JP7573288B2 - Devices and methods for treating edema - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 62/810,653 (filed February 26, 2019), U.S. Provisional Application No. 62/810,658 (filed February 26, 2019), U.S. Provisional Application No. 62/810,660 (filed February 26, 2019), U.S. Provisional Application No. 62/810,668 (filed February 26, 2019), and U.S. Provisional Application No. 62/810,672 (filed February 26, 2019), the contents of each of which are incorporated herein by reference.

(Technical field)
The present disclosure relates to devices and methods for the treatment of edema.

Congestive heart failure occurs when the heart cannot keep blood flowing and pumping enough to meet the body's needs. A person with heart failure may suffer from shortness of breath, extreme fatigue, and swelling of the limbs. Heart failure is a common and potentially fatal condition. In 2015, it affected approximately 40 million people worldwide, about 2% of all adults. As many as 10% of people over the age of 65 may be affected by heart failure.

In heart failure, pressure within the ventricles and atria becomes excessively elevated. As a result, the heart works harder to pump blood, leading to increased blood pressure that can result in edema forming within the body's interstitial compartments. Edema refers to the abnormal accumulation of fluid within the body's tissues and results when elevated blood pressure prevents lymphatic fluid from draining from the interstitium. The additional work of the heart weakens and remodels the heart over time, thus further reducing the heart's ability to function properly. Fluid accumulation leads to difficulty breathing and hospitalization for acute decompensated heart failure (ADHF). These conditions can have serious health consequences, including death.

The present invention provides a device and method for the treatment of edema using an indwelling catheter with an impeller to reduce pressure at the outlet of the lymphatic vessel and a balloon on the impeller to guide and restrict blood flow. The balloon restricts return flow from the jugular vein and guides the flow into the impeller cage. By forcing the flow into the impeller cage, the flow rate through the blood vessels can be increased, resulting in a lateral pressure reduction, resulting in a lymphatic outlet. As the lymphatic outlet experiences a pressure reduction, fluids within the lymphatic system drain to the outlet and into the circulatory system. These effects can be optimized by placing a balloon on or around the impeller cage, and in some embodiments, the balloon can be connected directly to the impeller cage, forming an annulus that surrounds the cage and funnels the flow into the impeller cage. The shape of the balloon in the deployed state guides and promotes blood flow into the inlet of the impeller. By using an impeller in conjunction with a balloon on the catheter, the ability of the device to reduce pressure at the lymphatic outlet is optimized.

The combined impeller cage and annular balloon geometry employs flow dynamics to drain the lymphatic system. The impeller cage, in combination with the balloon, creates a localized restriction (or occlusion) in the cross-sectional area of flow through the vessel (e.g., the brachiocephalic vein). This flow restriction creates a Venturi effect in which fluid pressure is reduced as applicable to the lymphatic outlet. Due to the reduced pressure experienced by the lymphatic outlet, lymphatic fluid drains from the lymphatic system to the circulatory system. Thus, the disclosed device and method utilizes the laws of fluid dynamics to drain lymphatic fluid using a balloon mounted on an impeller. The device and method of the present disclosure are useful for alleviating symptoms of edema, since operating an impeller in the brachiocephalic vein near the lymphatic outlet with a balloon connected to the impeller cage is effective to reduce pressure at the lymphatic outlet and drain lymphatic fluid. Thus, the present invention provides a method and device for treating edema and congestive heart failure using a balloon mounted on an impeller cage.

In one aspect, the present disclosure provides a device for treating edema. The device includes a catheter having a proximal portion and a distal portion, an impeller housing attached to the distal portion of the catheter with an impeller disposed therein, and an expandable member (e.g., a balloon) aligned over the outside of the impeller housing. The exterior surface of the expandable member may be physically coupled to the exterior surface of the impeller housing. Preferably, the exterior surface of the expandable member is physically coupled directly to the exterior surface of the impeller housing, i.e., without any membrane, sheath, or device between the exterior surface of the expandable member and the exterior surface of the impeller housing. The expandable member may surround the impeller housing.

When the expandable member is a balloon, the balloon may be inflatable and may surround the impeller housing. In some embodiments, the impeller housing is made of metal and a portion of the expandable member is secured to a surface of the metal by an adhesive. At least a portion of the surface of the metal may be impregnated with a polymer to promote bonding to the adhesive. An embodiment of the device may include a motor housing connected to a proximal portion of the catheter, with a motor disposed within the motor housing. A drive cable may extend from the motor through the catheter to the impeller, with an inflation lumen extending along the catheter to the expandable member. A related embodiment provides a method of using the device to treat edema. The method includes inserting a distal portion of the catheter into a patient's brachiocephalic vein, operating the impeller, and expanding the expandable member, thereby reducing pressure in the lymphatic vessel.

Aspects of the invention provide an edema treatment device including a catheter with a proximal portion and a distal portion, the distal portion being dimensioned for insertion into a lumen of a patient and including a pump, and an expandable member connected to the pump. When expanded, the expandable member includes an annular shape where a proximal surface of the annular shape directs fluid into the pump. Preferably, an inner radius of the annular shape is substantially the same as a radius of the proximal end of the pump. The expandable member may include an inflatable balloon mounted on the pump. In some embodiments, the pump includes an impeller housing with an impeller therein, the balloon mounted around at least a portion of the proximal end of the impeller housing. In certain embodiments, the impeller housing has a distal portion and a proximal portion, where an outer diameter of the proximal portion is smaller than an outer diameter of the distal portion, such that the expandable member is disposed around the proximal portion of the impeller housing when unexpanded. The impeller may have one or more blades on a shaft with a radius measured from the axis of the impeller to the outer edge of the blade that decreases from the distal portion to the proximal portion of the impeller. The outer edge of each blade may include a dog leg that defines the decreasing radius located adjacent the transition between the distal and proximal portions of the impeller housing. In a preferred embodiment, the distal portion of the impeller housing has an outlet and the impeller shaft flares outward near the distal end of the impeller such that when the impeller is rotated, the impeller pumps blood through the impeller housing and out of one or more outlets.

The pump may include an impeller disposed within the impeller housing, and the expandable member may include an inflatable balloon connected to an exterior surface of the impeller housing. In an embodiment, the balloon defines an annulus when inflated. A surface of the annulus may be attached to a surface of the impeller housing when the balloon is inflated. Preferably, when the expandable member is not expanded, a distal portion of the catheter may be threaded through a 12Fr introducer sheath.

Aspects of the present disclosure provide devices and associated methods that use a restrictor for compensation to pressure changes due to pump-induced flow. In the restrictor for flow compensation aspect, the present invention provides a method of treating edema. The method includes operating a pump to increase flow through the patient's innominate vein, and, following operation, deploying a restrictor upstream of the pump, thereby restricting flow from the jugular vein to the innominate vein to balance pressure downstream of the pump. The method may include operating the pump and then restricting flow once the increased flow through the innominate vein affects pressure in the jugular vein. The method may further include sensing, with a pressure sensor, an increase in pressure in the jugular vein due to the increased flow, and restricting flow in response to sensing the increased pressure in the jugular vein. The flow restriction may be adjusted according to the sensed pressure. Preferably, the method includes placing a device including a pump in the patient's vasculature prior to operation. The device includes a catheter dimensioned to be implanted at least partially within the vasculature, and the pump includes an impeller assembly disposed in a distal portion of the catheter. In some embodiments, a proximal portion of the catheter is connected to the motor housing, and the device includes a pressure sensor and a deployable restrictor attached to the catheter proximal to the pump. Preferably, the restrictor includes an inflatable balloon, and restricting the flow includes inflating the restrictor. The sensing may be performed using a computer system communicatively connected to the pressure sensor. The inflation of the restrictor may be adjusted periodically or continuously according to the sensed pressure.

Another aspect of the invention provides a method of treating edema. The method includes operating a pump to increase flow through the patient's brachiocephalic vein, sensing a pressure change in the patient's jugular vein due to the increased flow, and adjusting a restrictor based on the sensed pressure to restrict flow from the jugular vein to the brachiocephalic vein. The method may further include inserting a catheter into the brachiocephalic vein, the catheter including a pump, a pressure sensor, and a restrictor. Preferably, the restrictor includes an inflatable balloon, and adjusting the restrictor includes at least partially inflating the balloon. The sensing may be performed using a pressure sensor. The method may include periodically or continuously adjusting the inflation of the restrictor according to the sensed pressure. Preferably, the method includes adjusting the inflation to balance the pressure downstream of the pump. Optionally, the pump includes an impeller assembly disposed in a distal portion of the catheter. A proximal portion of the catheter may be connected to a motor housing having a motor therein operably coupled to the impeller assembly. In some embodiments, the catheter is coupled to a computer system operable to read the pressure or control the inflation.

Aspects of the invention provide purge-free systems, devices, and methods for the treatment of edema. For example, aspects provide a purge-free device including a catheter with a proximal portion and a distal portion, an impeller connected to the distal portion of the catheter, a motor connected to the proximal portion of the catheter, a drive cable extending from the motor to the impeller through the catheter, and an impermeable sleeve extending through the catheter and over the drive cable. The sleeve features a distal seal at the impeller and a proximal seal at the motor such that fluids outside the sleeve are prevented from entering the sleeve and contacting the drive cable. The sleeve and at least the distal seal exclude fluids from the drive cable. Either seal (or both) may include one or more O-rings. The device may include a first lumen and a second lumen both extending through the catheter, the first and second lumens having respective first and second proximal ends accessible outside the motor housing. Preferably, the first and second lumens are symmetrically positioned about the drive cable to provide balance to the device. The catheter preferably does not include a purge system or purge fluid. In some embodiments, the impeller is seated within the impeller housing, and the device also has at least one expandable member connected to a distal portion of the catheter. The expandable member may be connected to the impeller housing, and the device may also include a second expandable member disposed along the catheter. Preferably, the first expandable member comprises an annular balloon directly connected to a surface of the impeller housing. The device may also include at least one pressure sensor disposed along the catheter proximal to the impeller.

In some embodiments, the proximal seal includes an attachment between an impermeable sleeve and a portion of the impeller such that the attachment excludes fluids and allows the impeller and drive cable to rotate within the device.

A related aspect provides a method of using the purgeless device. The purgeless device may be used in a method of treating edema. The method includes inserting a distal portion of a catheter into a patient's brachiocephalic vein and driving an impeller connected to the distal portion of the catheter with a motor in a proximal portion of the catheter. The motor is connected to the impeller by a drive cable extending through the catheter. Driving the impeller reduces pressure in the lymphatic vessel. An impermeable sleeve extends through the catheter and over the drive cable such that bodily fluids outside the impermeable sleeve are prevented from entering the impermeable sleeve and contacting the drive cable. The method may further include inflating a restrictor disposed along a distal portion of the catheter to restrict flow from the jugular vein into the brachiocephalic vein, the inflation using an inflation lumen extending through the catheter outside the impermeable sleeve. The reduced pressure in the lymphatic vessel promotes drainage from the lymphatic system into the circulatory system.

Preferably, the impermeable sleeve has a proximal seal at the motor housing and a distal seal at the impeller. The proximal seal prevents blood and bodily fluids from escaping the patient through the motor housing or the proximal portion of the catheter. The distal seal may include a fitting between the impermeable sleeve and a portion of the impeller that excludes fluids and allows the impeller and drive cable to rotate within the device. The impermeable sleeve may be made of a polymer such as Teflon.

The method may include inflating at least one balloon disposed along the catheter with an inflation lumen having a proximal end accessible outside the motor housing while a distal portion of the catheter is inserted into the brachiocephalic vein. Blood and bodily fluids are preferably excluded from the drive cable without the use of a purge fluid or purge system.

Other aspects of the present disclosure relate to methods and devices that use and deliver anticoagulant agents to facilitate effective operation of the device for the treatment of edema. For example, aspects of the present disclosure provide a device including an intravascular pump with a built-in delivery mechanism for the anticoagulant agent (i.e., for delivering the anticoagulant agent to the moving parts of the pump). Thus, the present invention provides an edema treatment device including a catheter, an impeller assembly mounted to a distal portion of the catheter, and a drug lumen extending through the catheter and terminating substantially at an inlet of the impeller assembly such that drug released from the drug lumen flows through the inlet and the impeller assembly. Preferably, the catheter and impeller assembly are dimensioned for insertion through a patient's jugular vein. The device may further include a reservoir in fluid communication with the drug lumen. The impeller assembly may include an impeller housing with an impeller rotatably disposed therein. The device may include a motor connected to a proximal end of the catheter and operably connected to the impeller via a drive cable extending through the catheter. Preferably, the port is located in the impeller housing proximal to the impeller.

In some embodiments, the catheter comprises a tube with a drive cable extending therethrough with a cap connected around a distal portion of the tube. The impeller housing is mounted to the cap by a number of struts to define an inlet into the impeller housing. The cap seals the distal end of the flexible tube to the shaft of the impeller, and a port may be located in the cap. The impeller housing may have one or more outlets around a distal portion of the impeller such that movement of the impeller within the blood vessel drives blood into the impeller assembly via the inlets and out of the impeller assembly via the outlets.

The device may contain an anticoagulant (e.g., tirofiban, heparin, warfarin, rivaroxaban, dabigatran, apixaban, edoxaban, enoxaparin, or fondaparinux) in a reservoir. When the device is inserted into a patient's blood vessel and the impeller is operated, the anticoagulant is released from a port in the impeller cage, where it mixes with the blood and overflows across the rotating impeller.

A related aspect of the invention provides a method of treating edema. The method includes operating a pump to increase flow through a patient's brachiocephalic vein and releasing an anticoagulant at or adjacent to an inlet of the pump. The pump may include an impeller within a cage in a distal portion of the catheter, and the anticoagulant may be released from a port in or adjacent to a proximal portion of the cage. Optionally, the proximal end of the catheter terminates in a housing including a motor, the motor operably coupled to the impeller by a drive cable extending through the catheter. The catheter may include a drug lumen extending therethrough and terminating at a port. The method may include providing an anticoagulant in a reservoir in fluid communication with the drug lumen, inserting the catheter into the patient's vasculature and positioning the impeller in the brachiocephalic vein, operating the motor to drive the impeller, and overflowing the anticoagulant over the impeller by releasing the anticoagulant from the port. Preferably, operating the pump reduces pressure in the lymphatic vessels, thereby draining lymphatic fluid from the patient's lymphatic system.

In one embodiment, the pump includes an impeller on the distal portion of the catheter, and the anticoagulant is released from a port in the proximal portion of the impeller.

The release of the anticoagulant prevents clotting or thrombosis from interfering with the operation of the impeller. Optionally, the method may include restricting flow from the jugular vein to the brachiocephalic vein, thereby promoting flow from the subclavian vein to the brachiocephalic vein.

The present invention provides devices and methods useful for treating edema with an indwelling catheter that is placed in a patient's blood vessels and used to pump blood and cause a reduction in pressure at the outlet of the lymphatic vessels. The catheter pumps blood with an impeller, but is purge-free in that the catheter does not include a system for purging or washing the catheter components with a purge fluid. A purge-free catheter avoids blood-related mechanical complications such as clotting or thrombosis using an impermeable sleeve or shroud that protects the moving parts of the impeller drive system. For example, the drive cable to the impeller may be protected by an impermeable sleeve that is closed at the distal end by a distal seal near the impeller and also closed at the proximal end (e.g., outside the patient) by a proximal seal, such as an O-ring fitted to the motor housing and/or catheter handle used to navigate and drive the impeller into place. The impermeable sleeve or shroud and appropriate seals exclude blood and body fluids from entering the operable parts of the catheter system. Thus, the impermeable sleeve or shroud and any associated seals provide a purge-free system that maintains smooth and reliable operation of the catheter by excluding blood or bodily fluids from the operable parts of the catheter.

Edema may be treated by accessing a blood vessel, such as the jugular vein, and navigating a catheter through it. The catheter is navigated to position the impeller in the vicinity of the exit of the lymphatic vessel. For example, the impeller may be located in the brachiocephalic vein. A substantial length of the catheter and impeller may be positioned to seat within the vessel, and thus be surrounded by blood and operate inside it. To avoid problems that would result from clotting within the moving parts of the impeller or hemolysis induced by those moving parts, the catheter includes a sealed sleeve or shroud that excludes blood from the impeller and associated moving parts. The catheter may further include a proximal seal on the external motor housing that prevents blood from backing up and flowing outside the patient. A sealed sleeve or shroud is much easier to operate and maintain than an elaborate purge system that uses a purge fluid delivered by a purge lumen and prevents blood from interfering with device operation. Also, by not using a purge fluid, the purge-free system of the device and method of the present invention does not affect blood chemistry or osmolality because it does not release external fluids into the bloodstream. Thus, the present invention provides a device and method that uses a blood pump or impeller and a sealed sleeve or shroud on an intravascular catheter to reduce pressure at the lymphatic outlet while also preventing adverse effects such as clotting or hemolysis. The device and method of the present invention promotes drainage of lymphatic fluid from the lymphatic system because it reduces pressure at the lymphatic outlet. Thus, the device and method of the present invention can be used to treat edema or congestive heart failure.

The present invention provides a device and method for treating edema that uses an indwelling catheter to place an impeller in a patient's blood vessel near the exit of the lymphatic vessel. Operating the impeller creates a local drop in blood pressure, which promotes drainage of lymphatic fluid from the lymphatic system. The catheter is also used to release an anticoagulant, such as heparin, to clean and lubricate the impeller. Specifically, the anticoagulant prevents clotting, hemolysis, or thrombosis from occurring and interfering with the smooth operation of the impeller. The anticoagulant may be released using a drug lumen that extends along the catheter to a release port just upstream or just proximal to the impeller. A suspension or solution of anticoagulant is released to flow down the lumen and wash over the moving parts of the impeller, such as the impeller blades, the drive cable, and the bearing surfaces between the impeller and the surrounding impeller housing. The anticoagulant prevents blood from clotting at those locations and on those surfaces, thus avoiding the adverse effects of thrombosis or hemolysis.

By releasing an anticoagulant into the impeller, the device of the present invention operates smoothly and reliably within the patient's blood vessels. By using the impeller to drive blood flow and relieve pressure at the lymphatic outlet, the device of the present invention promotes drainage of lymphatic fluid from the lymphatic system into the circulatory system. Preferably, the impeller is provided by a catheter that releases an anticoagulant, such as heparin, at or near the inlet of the impeller cage. Due to the drainage of lymphatic fluid, the devices and methods of the present invention are useful for treating edema and congestive heart failure. Because the devices use an anticoagulant and maintain the smooth and reliable operation of the impeller, the device avoids being adversely affected by clotting or other effects. Thus, the devices and methods of the present invention are useful for treating edema and congestive heart failure.

The present invention provides a device and method for treating edema that uses an intravascular pump to pump blood through the circulatory system in such a manner as to relieve pressure at the outlet from the lymphatic system into the circulatory system. The device and method of the present invention further uses a flow restrictor in the circulatory system upstream of the pump to balance the pressure changes induced by the pump and compensate for downstream flow. The device may be provided as an indwelling intravascular catheter with a mechanical pump such as an impeller and a selectively deployable restrictor such as an inflatable balloon. Congestive heart failure or edema is treated by inserting a catheter and operating a pump in the circulatory system (e.g., in the brachiocephalic vein) just downstream of the outlet of the lymphatic vessel. Pumping blood away from the outlet of the lymphatic vessel tends to reduce the pressure at the outlet. The method of the present invention further uses a restrictor for flow compensation, restricting the upstream flow and thus amplifying or maintaining the pressure reduction at the lymphatic outlet.

Access may be gained through the jugular vein, and the catheter may be navigated (e.g., under radiological imaging) into position to position the pump just downstream of the lymphatic outlet. The proximal end of the catheter may house a motor connected to an impeller by a drive cable. Once the impeller is positioned within the brachiocephalic vein, operating the motor and driving the impeller pumps blood toward the heart and away from the lymphatic outlet, reducing pressure at the lymphatic outlet. Without the methods and devices of the present invention, blood return or flow through the jugular vein may simply increase, restoring hydrostatic equilibrium. To compensate for that effect, the catheter includes a selectively deployable restrictor, such as an inflatable balloon via an inflation lumen extending along the catheter. When the balloon is inflated, it blocks return flow through the jugular vein, thereby maintaining a local pressure drop at the lymphatic outlet. Due to the low pressure at the lymphatic outlet, lymphatic fluid flows out of the interstitial spaces within the body tissues, relieving pressure there and therefore reducing edema and protecting against congestive heart failure.

The devices and methods of the present invention therefore use an intravascular pump and a flow restrictor to reduce lymphatic pressure and compensate for increased circulation, respectively. These measures are effective in draining lymphatic fluid from the lymphatic system and thus reducing edema. Thus, the devices and methods of the present invention are useful for preventing congestive heart failure.

The present invention provides an impeller assembly with a structure that promotes flow without recirculation. When the impeller is rotated, the structural features of the impeller assembly act as vanes that direct the flow and induce a smooth flow of fluid through the impeller. Due to the vane-like features that make up the structure of the impeller assembly, the fluid flow through the impeller assembly is directed along smooth, continuous flow lines such that the overall flow pattern does not exhibit any vortices or recirculation. The impeller assembly can be connected to a distal portion of an intravascular treatment catheter and used to treat edema.

By navigating a catheter into the jugular vein of a patient suffering from edema and operating an impeller in the vicinity of the lymphatic vessels, the device promotes and increases blood flow along the jugular vein, which, according to Bernoulli's principle, reduces pressure at the outlet of the lymphatic vessels. Because pressure is reduced at the outlet of the lymphatic vessels, lymphatic fluid drains from the lymphatic system into the circulatory system, thereby providing relief from the adverse effects and symptoms of edema.

Additionally, the impeller assembly can include a special combination of structures to promote flow therethrough. For example, the impeller assembly can have an inflatable balloon disposed thereon. An inflation lumen extends down the catheter and through rigid struts extending from the catheter to the impeller housing. Some of the rigid struts collectively support the housing against the catheter. One or any number of the rigid struts can each have an inflation lumen extending therethrough. However, the lumen need not be concentrically disposed within the struts, and in preferred embodiments, is eccentric with the struts and bears against the lumen excess material standing in the interior space of the impeller housing. The excess material extending inward from each strut acts as a flow directing vane that directs the flow into a smooth pattern without vortexes or recirculation. Since the primary benefit of the intravascular impeller is its ability to efficiently pump blood through it, efficient operation without recirculation or vortexing provides an optimized therapeutic tool for reducing the effects and symptoms of edema.

In one aspect, the present invention provides a device for treating edema. The device includes a catheter with a proximal portion and a distal portion. An impeller assembly is connected to the distal portion. The impeller assembly has an impeller operably disposed therein. The proximal portion of the impeller assembly is configured to promote flow into an inlet of the impeller assembly without recirculation. When the impeller operates within a blood vessel, blood flows through a housing of the impeller assembly without recirculation.

The impeller assembly may include a cap secured to the distal portion and one or more struts extending from the cap to the housing. The housing may have a diameter greater than the diameter of the cap such that the proximal base of the housing, the cap, and the one or more struts define an inlet. In some embodiments, the strut includes an inflation lumen extending therethrough for inflating a balloon mounted on the impeller assembly. Preferably, the strut is generally parallel to the axis of the impeller and projects radially inward from at least a portion of the inner surface of the impeller housing. Such struts may define vanes within the impeller assembly that direct fluid flow as the impeller operates, thereby preventing recirculation or vortexes. The struts may include a fluid lumen extending therethrough, the fluid lumen being non-concentric with at least a portion of the body of the strut due to the material of the strut forming the vanes within the impeller assembly. The device may have several of the struts, e.g., three, each defining a vane within the impeller assembly that directs fluid flow as the impeller operates, thereby preventing recirculation or vortexes. The device may optionally include a drug lumen that extends through the catheter and terminates substantially within a proximal portion of the impeller assembly, such that drug released from the drug lumen flows through the inlet and the impeller assembly.

In one embodiment, the catheter includes a tube with a cap connected around a distal portion of the tube and with a drive cable extending therethrough, with the impeller housing mounted to the cap by a plurality of struts that define vanes that promote laminar flow of fluid through the impeller assembly. The impeller housing may have one or more outlets around a distal portion of the impeller such that motion of the impeller within the vessel drives blood into the impeller assembly through the inlet and out of the impeller assembly through the outlet such that the blood exhibits smooth laminar flow without recirculation or vortexes.

Aspects of the invention provide a method of treating edema. The method includes inserting a distal portion of a catheter into a patient's brachiocephalic vein. The catheter includes an impeller assembly on the distal portion. Driving an impeller disposed within the impeller assembly reduces pressure in the lymphatic vessel. A proximal portion of the impeller assembly is configured to promote flow into an inlet of the impeller assembly without recirculation.

The catheter may include a cap secured to the distal portion and one or more struts extending from the cap and supporting a housing of the impeller assembly. The housing may have a diameter greater than that of the cap, and the proximal base of the housing, the cap, and the one or more struts may define an inlet. The struts may extend generally parallel to the axis of the impeller and project radially inward from at least a portion of an inner surface of the impeller housing. The struts may define vanes within the impeller assembly that direct fluid flow as the impeller operates, thereby preventing recirculation or vortexes. One or more of the struts may include a fluid lumen that is non-concentric with at least a portion of the body of the strut due to the material of the strut that forms the vanes in the impeller assembly.

The method may include inflating an inflatable flow restrictor mounted on the impeller assembly by delivering an inflation fluid to the restrictor via an inflation lumen extending through the catheter. The impeller housing may include one or more outlets about a distal portion of the impeller such that operation of the impeller within the blood vessel drives blood into the impeller assembly via the inlet and out of the impeller assembly via the outlet such that the blood exhibits smooth laminar flow without recirculation or vortexes.
The present invention provides, for example, the following:
(Item 1)
A device, the device comprising:
a catheter having a proximal portion and a distal portion;
an impeller housing attached to a distal portion of the catheter, the impeller housing having an impeller disposed therein;
an expandable member aligned on an exterior of the impeller housing; and
A device comprising:
(Item 2)
2. The device of claim 1, wherein an exterior surface of the expandable member is physically coupled to an exterior surface of the impeller housing.
(Item 3)
3. The device of claim 2, wherein the exterior surface of the expandable member is directly physically coupled to the exterior surface of the impeller housing without any membrane, sheath, or device between the exterior surface of the expandable member and the exterior surface of the impeller housing.
(Item 4)
2. The device of claim 1, wherein the expandable member surrounds the impeller housing.
(Item 5)
2. The device of claim 1, wherein the expandable member is a balloon.
(Item 6)
6. The device of claim 5, wherein the balloon is inflatable, and further wherein the balloon surrounds the impeller housing.
(Item 7)
2. The device of claim 1, wherein the impeller housing comprises metal and a portion of the expandable member is secured to a surface of the metal by an adhesive.
(Item 8)
8. The device of claim 7, wherein at least a portion of the surface of the metal is impregnated with a polymer to promote bonding to the adhesive.
(Item 9)
a motor housing connected to a proximal portion of the catheter;
a motor disposed within the motor housing;
a drive cable extending through the catheter from the motor to the impeller;
an inflation lumen extending along the catheter to the expandable member;
Item 1. The device of item 1, further comprising:
(Item 10)
13. A method of using the device described in item 1 for treating edema, the method comprising inserting the distal portion of the catheter into a patient's brachiocephalic vein, operating the impeller, and expanding the expandable member, thereby reducing pressure in a lymphatic vessel.
(Item 11)
A device, the device comprising:
a catheter having a proximal portion and a distal portion, the distal portion being dimensioned for insertion into a lumen of a patient, the distal portion comprising a pump;
an expandable member connected to the pump;
Equipped with
When expanded, the expandable member comprises an annular shape, the proximal surface of the annular shape directing fluid into the impeller housing.
(Item 12)
Item 12. The device of item 11, wherein the inner radius of the annular shape is substantially the same as the radius of the proximal end of the impeller housing.
(Item 13)
12. The device of claim 11, wherein the expandable member comprises an inflatable balloon mounted on the pump.
(Item 14)
Item 14. The device of item 13, wherein the pump comprises an impeller housing having an impeller therein, and the balloon is mounted around at least a portion of a proximal end of the impeller housing.
(Item 15)
Item 15. The device of item 14, wherein the impeller housing comprises a distal portion and a proximal portion, an outer diameter of the proximal portion being smaller than an outer diameter of the distal portion, and the expandable member is disposed around the proximal portion of the impeller housing when unexpanded.
(Item 16)
Item 16. The device of item 15, wherein the impeller comprises one or more blades on a shaft, and wherein a radial measurement taken from the axis of the impeller to an outer edge of the blade decreases from a distal portion to a proximal portion of the impeller.
(Item 17)
17. The device of claim 16, wherein an outer edge of each blade includes a dogleg defining a diminishing radius located adjacent a transition between the distal and proximal portions of the impeller housing.
(Item 18)
Item 16. The device of item 15, wherein the distal portion of the impeller housing includes one or more outlets and the impeller shaft flares outward near a distal end of the impeller, such that when the impeller is rotated, the impeller pumps blood through the impeller housing and out the one or more outlets.
(Item 19)
12. The device of claim 11, wherein the pump comprises an impeller disposed within an impeller housing, and the expandable member comprises an inflatable balloon connected to an exterior surface of the impeller housing.
(Item 20)
20. The device of claim 19, wherein when the balloon is inflated, the balloon defines a toroid.

FIG. 1 shows a device for the treatment of edema. FIG. 2 provides a detailed view of the impeller assembly. FIG. 3 shows the expandable member in a deployed state. FIG. 4 shows the motor housing connected to the catheter. FIG. 5 shows steps of a method of using the device to treat edema. FIG. 6 is a detailed view of the impeller assembly with the expandable members in a deployed state. FIG. 7 illustrates a method of treating edema using a restrictor to balance pressure and compensate for downstream flow. FIG. 8 shows a restrictor and pressure sensor for the balancing and compensation method. FIG. 9 shows the device inserted into a patient's vascular system. FIG. 10 illustrates a related method for treating edema using a restrictor for balancing/compensation. FIG. 11 is a detailed view of the features that provide a purge-free system. FIG. 12 illustrates a method of treating edema using a no-purge device. FIG. 13 illustrates a portion of an intravascular device for the treatment of edema that releases an anticoagulant in an intravascular pump. FIG. 14 is a cross-sectional view through the impeller assembly. FIG. 15 shows the results of the computerized flow model. FIG. 16 is a partial cutaway view of the impeller assembly. FIG. 17 is a side view of the impeller assembly. FIG. 18 illustrates an exemplary inlet region of the impeller assembly. FIG. 19 shows the inlet region with an internal inflation lumen. FIG. 20 is a detailed view of the proximal inlet. FIG. 21 shows a side view of an impeller assembly with a rectangular proximal inlet. FIG. 22 shows an impeller assembly with an arcuate proximal strut. FIG. 23 shows a side view of the proximal portion of the impeller assembly. FIG. 24 illustrates the impeller assembly. FIG. 25 shows an elongated impeller assembly. FIG. 26 shows a cross-sectional view of the impeller assembly. FIG. 27 is a cross-sectional view of the impeller assembly inside the vein. 28A-F illustrate the attachment and folding of the expandable member. 28A-F illustrate the attachment and folding of the expandable member. 28A-F illustrate the attachment and folding of the expandable member. FIG. 29 shows an impeller assembly with an expandable member having an elongated surface for interfacing with a vessel wall. FIG. 30 shows an impeller assembly with a two-part expandable member. FIG. 31 is a partial cross-sectional view of the distal portion of the catheter. FIG. 32 is a partial cross-sectional view of a self-expanding impeller assembly. FIG. 33 shows a partial cross-sectional view of the impeller assembly. FIG. 34 shows the inlet to the impeller assembly. FIG. 35 is an exemplary catheter system. FIG. 36 shows a catheter with an expandable member slidably mounted along the shaft of the catheter. FIG. 37 shows fluid channels traversing the expandable member that allow for a controlled amount of blood flow. FIG. 38 shows a catheter with an alternative bypass channel. FIG. 39 shows the patient interface with the sheath in place. FIG. 40 shows a patient interface with a sheath held in place by an adhesive membrane. FIG. 41 shows a flow control sheath. FIG. 42 shows the proximal portion of the catheter system. FIG. 43 illustrates a locking mechanism for securing the catheter shaft to the hub of the sheath during therapy. FIG. 44 shows the locking mechanism engaged with the catheter shaft. FIG. 45 shows a schematic diagram of the push-lock mechanism. FIG. 46 shows an alternative locking mechanism. FIG. 47 is a partial cutaway view of the jugular vein showing a flow control sheath inserted therein. FIG. 48 shows an indwelling catheter system. FIG. 49 is a cross-sectional view taken along line AA of FIG. FIG. 50 shows an indwelling catheter. FIG. 51 is an expanded view of dotted circle B of FIG. 50, in accordance with an embodiment of the present invention. FIG. 52 is an expanded view of dotted circle B of FIG. 50, according to another embodiment of the present invention. FIG. 53 is an expanded view of dotted circle B of FIG. 50, according to a different embodiment of the present invention. FIG. 54 illustrates distal flushing of an indwelling catheter. FIG. 55 illustrates distal flushing of an indwelling catheter according to a different embodiment. FIG. 56 shows an indwelling catheter with a purging system. FIG. 57 shows a cross-sectional view of the central lumen taken along line AA of FIG. 56, according to one embodiment of the present invention. FIG. 58 shows a cross-sectional view of the central lumen taken along line AA of FIG. 56, according to a different embodiment of the present invention. FIG. 59 shows a cross-sectional view of the central lumen taken along line AA of FIG. 56, according to another embodiment of the present invention. FIG. 60 shows an optimized guide surface for the cage inlet. FIG. 61 shows a suboptimal guide surface. FIG. 62 shows the cage entrance. FIG. 63 shows a suboptimal inlet configuration.

The present disclosure relates to devices and methods for treating edema or congestive heart failure. The disclosed devices include catheters dimensioned for insertion through the jugular vein, which may use or include various features, either alone or in combination, as described herein. Device embodiments include treatment devices in which a flow restrictor, such as a balloon, is mounted on an intravascular pump or impeller cage or housing. In some of these embodiments, the shape of the balloon in a deployed state directs and promotes blood flow into the inlet of the impeller. In certain embodiments, the disclosed devices include an impeller having a smaller diameter proximal end compared to the distal end to compensate in size for the positioning of the balloon on the impeller cage. Aspects of the invention relate to purge-free systems or purge-free intravascular treatment catheters that do not use a purge fluid and protect the impeller from thrombosis or clotting. In certain embodiments, the disclosed devices and methods use the release of an anticoagulant, such as heparin, at the inlet of the impeller cage. Other embodiments of the present disclosure relate to devices and methods that use restrictors, such as balloons, to balance pressure and compensate for downstream flow when the impeller is operated to drain lymphatic vessels. Features and embodiments of the present disclosure include an edema treatment device that includes an arrangement of lumens that are symmetrical about the drive shaft to provide balance to the drive shaft. In some embodiments, the lumens have a proximal end outside the motor housing and extend down to the distal portion of the catheter. The devices of the present disclosure may include an atraumatic tip with threads therein to allow for smooth material transitions. An embodiment of the present disclosure may include a guidewire extending through the impeller cage. These embodiments are described and illustrated in further detail herein and may be present in any combination in the devices of the present disclosure.

FIG. 1 shows a device 101 for the treatment of edema. The device 101 includes a catheter 105 with a proximal portion 109 and a distal portion 115. An impeller housing 203, with an impeller disposed therein, is attached to the distal portion 115 of the catheter 105. An expandable member 301 may be aligned over the outside of the impeller housing 203. The expandable member 301 is depicted in a collapsed configuration and thus appears to be nothing more than a smooth continuation of the impeller housing 203.

The device 101 may include a restrictor 801 and at least one pressure sensor 805. In the depicted embodiment, the restrictor 801 is proximal to the expandable member 301. Preferably, each of the restrictor 801 and the expandable member 301 is independently selectively deployable to restrict, impede, direct, or guide fluid flow around the relevant portion of the device 101. In a preferred embodiment, each of the restrictor 801 and the expandable member 301 is in fluid communication with a dedicated inflation lumen extending along the length of the catheter 105.

One feature of the device 101 is the impeller 205 preferably provided within an impeller assembly 201 that provides an impeller housing 203 and other mechanical features such as ports and openings useful for pumping blood and fluids within the patient's blood vessels.

2 provides a detailed view of the impeller assembly 201. The impeller assembly 201 includes an impeller housing 203 with an impeller 205 rotatably disposed therein. An expandable 301 member is aligned over the exterior of the impeller housing 203. The expandable member is represented in FIG. 2 using dashed lines (imaginary lines to aid in viewing other features of the device 101). The dashed lines represent the location and placement of the expandable member 301 in its collapsed or undeployed state. The impeller housing 203, with the impeller disposed therein, is attached to the distal portion 115 of the catheter 105. An expandable 301 member is aligned over the exterior of the impeller housing 203. The expandable member is represented in FIG. 2 using dashed lines (imaginary lines to aid in viewing other features of the device 101). The dashed lines represent the location and placement of the expandable member 301 in its collapsed or undeployed state.

As shown, the impeller 205 has blades 206 on a shaft 207. The radius measured from the axis of the impeller 205 to the outer edge of the blades 206 decreases from the distal to the proximal portion of the impeller. This can be seen in that the outer edge of each blade 206 includes a dog leg 209 that defines a decrease in radius, located adjacent the transition between the distal and proximal portions of the impeller housing 203.

When the distal portion 115 of the device 101 is inserted into the vascular system of a patient and the motor in the motor housing 401 is operated, the impeller 205 rotates and drives fluid (i.e., blood) through the impeller housing 203. To that end, the proximal end of the impeller housing 203 includes one or more inlets 255 and the distal portion of the impeller housing 203 includes one or more outlets 227. The impeller shaft 207 flares outward near the distal end of the impeller 205 such that when the impeller 205 is rotated, the impeller pumps blood through the impeller housing 203 and out the one or more outlets 227.

FIG. 14 is a cross-sectional view through the impeller assembly 201 on the distal portion 115 of the device 101. The impeller assembly 201 includes an impeller housing 203 with an impeller 205 rotatably disposed therein.

The impeller assembly 201 is connected to the distal portion 115 of the catheter. The impeller assembly has an impeller 205 operably disposed therein. A cutaway view of the impeller assembly 201 shows that the proximal portion of the impeller assembly is configured to promote flow into the inlet of the impeller assembly without recirculation.

When the impeller 205 operates within a blood vessel, blood flows through the housing 203 of the impeller assembly 201 without recirculation.

As illustrated by the cross-sectional view, in the depicted embodiment, the impeller assembly 201 includes a cap 249 secured to the distal portion 115 and one or more struts 1405 extending from the cap 249 to the housing 203. Any one or more of the struts 1405 may include a lumen 415. The housing 203 has a diameter that exceeds the diameter of the cap 249. Characteristically, the proximal base of the housing 203, the cap 249, and the one or more struts 105 may be seen to define one or more inlets into the impeller housing 201.

In the depicted embodiment, the struts 1405 include an inflation lumen 415 extending therethrough for inflating a balloon mounted on the impeller assembly. The struts 1405 are generally parallel to the axis of the impeller 205 and project radially inward from at least a portion of the inner surface of the impeller housing 203. When so structured, each strut 1405 defines a vane within the impeller assembly 201 that directs fluid flow as the impeller 205 operates, thereby preventing recirculation or vortexes.

As shown, the strut 1405 has a fluid lumen 415 extending therethrough. The fluid lumen 415 is non-concentric with at least a portion of the body of the strut 1405 due to the material of the strut 1405 that forms the blades in the impeller assembly 201. For example, with reference to FIG. 3, it can be seen that the device 101 can include a plurality of struts, at least three. Together, the struts define the blades in the impeller assembly that direct the fluid flow as the impeller operates, thereby preventing recirculation or vortexes.

The impeller housing 201 includes one or more outlets 258 around a distal portion of the impeller 205. Operation of the impeller 205 within the blood vessel drives blood into the impeller assembly 201 via the inlet 255 and out of the impeller assembly 201 via the outlet 258 such that the blood exhibits smooth laminar flow without recirculation or vortexes.

Figure 15 shows how blood flows through impeller assembly 201 via inlet 255 and out of impeller assembly 201 via outlet 258 such that the blood exhibits smooth laminar flow without recirculation or vortexes. The images depict the results of a computerized flow model. The flow model shows that the flow through the impeller assembly with the structure of the present invention is smooth and does not exhibit recirculation.

Model testing results show smooth and efficient flow, so the device of the present invention pumps blood pressure more efficiently than other devices lacking the structures shown herein.

Computer model testing shows that the flow is smooth and there are no vortexes or recirculations within the flow.

The device of the present invention is beneficial for treating patients with edema because it pumps blood pressure more efficiently than other devices and without vortex or recirculation. Thus, using the device of the present invention, a clinician may perform a method of treating edema. The method includes inserting a distal portion 115 of a catheter into the brachiocephalic vein of a patient. The catheter has an impeller assembly 201 on the distal portion 115. The method includes driving an impeller 205 disposed within the impeller assembly 201, thereby reducing pressure in the lymphatic vessel. The proximal portion of the impeller assembly 201 is configured to promote flow into the inlet of the impeller assembly without recirculation, as clearly shown in the depicted computer flow model. The catheter may have any of the other features disclosed herein (e.g., the housing has a diameter greater than the diameter of the cap, the proximal base of the housing, the cap, and one or more struts extending from the cap defining an inlet and secured to the distal portion with one or more struts supporting the housing of the impeller assembly).

As shown by the resulting image from the computer flow model, the struts define the blades in the impeller assembly that direct the fluid flow as the impeller operates, thereby preventing recirculation or vortices. The flow lines that appear clearly in the computer flow model avoid any loops that would appear if the flow had recirculations or vortices. Because the flow through the impeller assembly 201 did not have recirculations or vortices, the image from the computer flow model shows only flow lines that do not have loops, circles, spirals, etc.

The impeller housing includes one or more outlets about a distal portion of the impeller. When the impeller is operated within a blood vessel, the impeller drives blood into the impeller assembly through the inlets and out of the impeller assembly through the outlets such that the blood exhibits smooth laminar flow without recirculation or vortexes.

The devices and methods of the present disclosure may include other features.

The device 101 of the present disclosure may further include a drug lumen 251 that extends through the catheter 105 and substantially terminates at the inlet 255 of the impeller assembly 201. In some embodiments, the impeller assembly 201 also includes an atraumatic tip 231 with a threaded fitment 237 therein to allow for a smooth transition in material properties between the rigid impeller cage 203 (e.g., metal) and the softer material of the atraumatic tip 239. The tip 239 preferably includes a suitable soft material, such as a polymer. The material may include, for example, a polyether block amide, such as those sold under the trademark PEBAX by Arkema Inc. (King of Prussia, PA). Although polyether block amide is detailed, the polymer may be comprised of any number of other polymers such as polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), polyurethane, polypropylene (PP), polyvinyl chloride (PVC), polyetherester, polyester, polyamide, elastomeric polyamide, block polyamide/ether, silicone, polyethylene, Marlex high density polyethylene, linear low density polyethylene, polyetheretherketone (PEEK), polyimide (PI), or polyetherimide (PEI). The threaded fitment 237 may include a threaded post (e.g., of metal or plastic such as polycarbonate) that is threadably fitted to both the impeller housing 203 and the atraumatic tip 231. By including a long post for the fitment 237 (e.g., longer than its own maximum diameter, preferably at least about 2 or 3 times longer), the tip 231 may deform but is prevented from assuming or exhibiting any kinks or discontinuities. Additionally, as shown, the tip 231 may include a guidewire lumen 239.

The expandable member 301 on the impeller assembly 201 is depicted in a collapsed configuration using dashed lines. The impeller assembly 201 operates as a pump and includes an impeller 205 disposed within an impeller housing 203. In a preferred embodiment, the expandable member 301 comprises an inflatable balloon connected to an exterior surface of the impeller housing 203.

FIG. 3 shows the expandable member 301 in a deployed state. In the depicted embodiment, the expandable member 301 is provided as a balloon. As shown, when the balloon is inflated it defines a toroid. The exterior surface of the expandable member 301 is physically coupled to the exterior surface of the impeller housing 203 (e.g., the balloon can be glued to the housing 203 using an adhesive).

Preferably, the exterior surface of the expandable member 301 is physically directly coupled to the exterior surface of the impeller housing 203 without any membrane, sheath, or device 101 between the exterior surface of the expandable member 301 and the exterior surface of the impeller housing 203. The expandable member 301 may partially or completely surround the impeller housing 203. The expandable member 301 may be provided as an inflatable balloon that surrounds the impeller housing 203.

The devices of the present disclosure may include features to facilitate bonding of the balloon to the impeller housing 203. For example, the impeller housing may include a metal (e.g., stainless steel, steel, aluminum, titanium, nickel-titanium alloy, etc.) and a portion of the expandable member 301 may be secured to the metal surface by an adhesive. To facilitate bonding, at least a portion of the metal surface may be impregnated with a polymer. In some embodiments, the metal surface at least on the exterior proximal portion of the impeller cage 203 is impregnated with polyurethane to a depth of at least 3 μm.

Using the expandable member 301 mounted to the impeller cage 203, the device 101 is configured for placement within a body vessel. The impeller housing has an axis that may be placed generally parallel to the axis of the vessel. Preferably, the expandable member 301 is impermeable to flow across the expandable member. The expandable member 301 is configured to appose the vessel wall in use and, in doing so, direct fluid flow to the inlet of the impeller housing 203.

In use, the expandable member 301 anchors or holds the impeller assembly 201 in a fixed position relative to the axis of the blood vessel. In its anchored state, the expandable member 301 conforms to the vessel wall in the region of apposition, which region comprises a generally cylindrical section of the vessel wall. The central axis of the expandable member and the central axis of the impeller housing are preferably substantially the same.

The expandable member is configured to allow the axis of the impeller housing to articulate relative to the axis of the balloon, in use. The articulation of the impeller relative to the balloon preferably provides two degrees of freedom.

In some embodiments, the expandable member 301 comprises a balloon, the membrane of which has an omega shape in cross section.

The impeller housing 203 may include a tubular member, the wall of which may include a hole extending through the wall of the tubular member and at least partially defining an inflation port for the balloon. Preferably, the inflation port is connected to an inflation system external to the patient via a catheter. The connection may include a formed metal tube or tubing that couples to the inflation port and forms a seal therewith (i.e., is "hermetically coupled thereto"). In some embodiments, the coupling of the expandable member to the impeller housing includes at least one circumferential seal around the outer diameter of the housing. More preferably, the coupling of the expandable member to the impeller housing includes a first circumferential seal around the outer diameter of the housing and a second circumferential seal around the outer diameter, the second circumferential seal being axially spaced from the first circumferential seal. In some embodiments, the circumferential seal has an axial length, with a portion of the seal surrounding the inflation port extending across the walls of the impeller housing and the expandable member. The impeller housing may include an expansion port positioned between the first circumferential seal and the second circumferential seal.

2 and 3, preferably the balloon has a collapsed state (FIG. 2) for delivery and retrieval, and an expanded state (FIG. 3). In some embodiments, in the collapsed state, at least a portion of the balloon material can slide relative to the axis of the impeller housing (i.e., axially slidable relative to the impeller housing). For example, at least a portion of the balloon material can be configured to slide proximally during delivery and slide distally during retrieval. It can be provided that the balloon comprises an annular shape with a first constriction and a second constriction coupled to the impeller housing. Preferably, the distance between the first constriction and the second constriction is less than the circumference of the annular balloon.

The bond between the expandable member 301 and the impeller housing 203 may include an interface layer. For example, the interface layer may include an interpenetration layer. In an embodiment, the impeller housing includes a gap and the interpenetration layer includes interpenetration of material into the gap of the impeller housing. The interpenetration layer may include a tie layer, which may include an acrylate material.

In some embodiments, the expandable member 301 is configured to apply a radially outward force to the vessel wall. The device may be configured such that the application of the outward radial force substantially fixes at least a portion of the impeller housing 203 to the central axis of the vessel. The impeller housing comprises an inner lumen extending from a proximal section of the impeller housing to a distal section or outlet of the housing, the inner lumen configured to house the impeller 205. The impeller housing comprises a first diameter adjacent the proximal section and a second diameter adjacent the distal section. In certain embodiments, the diameter of the inner lumen of the impeller housing varies between the proximal and distal sections. Similarly, the radial dimension of the impeller blades 206 may vary between the proximal and distal sections. The diameter of the variation of the inner lumen diameter of the impeller housing may define a tapered, step, multiple steps, multiple tapers, dogbone, parabola, or combinations thereof. The impeller blades are configured to fluidly engage the inner lumen of the impeller housing. Preferably, the impeller blades 206 are configured to have clearance with the inner lumen of the impeller housing. The impeller assembly 201 has at least one inlet opening and at least one outlet opening. The at least one inlet opening and the at least one outlet opening may be separated by a distance of 1-40 millimeters. Preferably, the at least one inlet opening and the at least one outlet opening may be about 5 millimeters apart, positioning the proximal end of the impeller 205 about 0.5 millimeters from the distal edge of the inlet. This configuration is preferred as it helps to minimize recirculation at the transition from the inlet to the impeller 205. For example, in FIG. 25, in some embodiments discussed herein, the distance between the inlet and outlet may extend to about 25-30 millimeters. This configuration provides a more laminar flow within the impeller 205. In other embodiments, the at least one inlet opening and the at least one outlet opening may be approximately 3 millimeters apart to bring the impeller 205 closer to or just inside the inlet. The at least one inlet opening has a proximal end and a distal end. A proximal portion of the annulus extends proximal to the distal end of the proximal inlet opening and defines an entry funnel into the inlet opening. The distal portion 115 of the catheter 101 is configured for insertion into a blood vessel of a patient, and the proximal portion 109 of the catheter 101 is configured to extend outside of the patient.

The proximal portion 109 of the catheter 101 may terminate in the motor housing 401.

FIG. 4 shows a motor housing 401 connected to the proximal portion 109 of the catheter 105. The motor 405 is disposed within the motor housing 401. A drive cable 411 extends from the motor 405 through the catheter 105 to the impeller. In a preferred embodiment, an inflation lumen 415 extends along the catheter 105 to the expandable member 301. The drive cable 411 preferably extends through a sleeve within the catheter 101, such as the impermeable sleeve 121. In a non-purging embodiment, the impermeable sleeve 121 may include a seal at one or both ends to exclude fluid from the drive cable 411. The impermeable sleeve 121 abuts the motor housing 401 at a proximal seal 433.

In one embodiment, the motor 405 includes a rotor operable to rotate at high speeds, and the catheter 101 includes a drive cable 411 for transmitting the rotational speed through the catheter 101 to the impeller 205. The drive cable 411 may be capable of transmitting rotational speeds of greater than 5,000 rpm (e.g., >10,000 rpm, >15,000 rpm, or >20,000 rpm) to the impeller 205. Most preferably, the catheter is configured for heat-free operation while transmitting high rotational speeds to the impeller.

The impermeable sleeve 121 may comprise a material such as polytetrafluoroethylene (PTFE). For example, the impermeable sleeve 121 may be provided by thick-walled PTFE tubing. The thick-walled PTFE tubing may have a wall thickness greater than 75 micrometers, preferably greater than >100 microns, >125 microns, or greater than 150 microns. Optionally, the drive shaft has a second moment of area with a value. The drive cable 411 may comprise a cylindrical superelastic member over at least a portion of the length of the drive shaft. The clearance between the drive shafts may be less than a few micrometers. In some embodiments, the impermeable sleeve 121 is made of a hydrophobic material. The impermeable sleeve 121 may comprise a material with a Hildebrand solubility parameter (δ) of less than 16 MPa ^∧ (0.5). The impermeable sleeve 121 may comprise a material with a Hildebrand solubility parameter of less than 4 MPa ^∧ (0.5). For example, the δ of nylon is about 15.7 MPa ^∧ 0.5 and the δ of polytetrafluoroethylene (PTFE) is about 6.2 MPa ^∧ 0.5. The impermeable sleeve 121 may comprise a PTFE material and the drive cable 411 may comprise a Nitinol rod, with the gap between the rod and the sleeve being less than a few microns. Preferably, the concentricity of the rod is greater than 95%. The drive cable may have a first diameter and a second diameter, the first diameter being slightly larger than the second diameter. The impermeable sleeve may comprise a polymeric material with a dynamic coefficient of friction less than 0.08, or less than 0.07, 0.06, or 0.05.

The disclosed devices are useful for treating edema or congestive heart failure. The disclosed devices can be used to operate a pump to promote flow in the brachiocephalic vein and result in a reduction in pressure at the output of the lymphatic vessels that drain lymph from the lymphatic system. To compensate for what would otherwise be a change in pressure in the circulatory system that would result from operating the pump, the disclosure provides a method of compensating for the pressure change.

Figure 5 shows steps of a method 501 of using the device 101 to treat edema.

The method 501 includes inserting 510 the distal portion 115 of the catheter 105 into the patient's brachiocephalic vein 939, operating 515 the impeller, and expanding 517 the expandable member 301, thereby reducing pressure in the lymphatic vessel 907.

The method 501 may include the use of a device 101 including a catheter with a proximal portion 109 and a distal portion 115, the distal portion 115 being sized for insertion into a lumen of a patient. The device 101 includes a pump (e.g., an impeller assembly 201) and an expandable member 301 connected to the pump. When expanded, the expandable member 301 includes an annular shape, and a proximal surface of the annular shape directs fluid into the impeller housing 203. Preferably, the inner radius of the annular shape is substantially the same as the radius of the proximal end of the impeller housing 203. In some embodiments, the expandable member 301 includes an inflatable balloon mounted on the pump. The pump includes an impeller housing 203 with an impeller therein, the balloon mounted around at least a portion of the proximal end of the impeller housing 203. The impeller housing 203 may include a distal portion and a proximal portion, the outer diameter of the proximal portion being smaller than the outer diameter of the distal portion. When the expandable member 301 is unexpanded, it is disposed around the proximal portion of the impeller housing 203. When the balloon is inflated, the surface of the toroid is attached to the surface of the impeller housing 203. When the expandable member 301 is unexpanded, the distal portion 115 of the catheter 105 can be threaded through the 12Fr introducer sheath.

6 is a detailed view of the impeller assembly 201 with the expandable member 301 in a deployed state. The impeller 205 sits substantially within and/or just downstream of the deployed restrictor. An inflation lumen 415 extends through the distal portion 115 of the catheter and terminates at a port 601 into the expandable member 301. Visual inspection of the surfaces of the expandable member 301 on the proximal and inner surfaces of the impeller housing 203 reveals that they form a smooth continuous surface that funnels fluid under the impeller's propulsive force through the impeller housing 203. This drives blood through the vessel and modulates nearby fluid pressure. When operated substantially within the brachiocephalic vein, pressure at the lymphatic outlet is reduced, which promotes lymphatic drainage and reduction of edema.

7 illustrates a method 701 for treating edema. The method 701 includes the steps of operating 710 a pump to increase flow through the patient's brachiocephalic vein 939, and, following the operating step, deploying 717 a restrictor upstream of the pump, thereby restricting flow from the jugular vein to the brachiocephalic vein 939 to balance 729 pressure downstream of the pump. The method 701 may include the steps of operating the pump and then restricting flow once the increased flow through the brachiocephalic vein 939 affects the pressure in the jugular vein.

Method 701 preferably includes step 715 of sensing, with pressure sensor 805, an increase in pressure in the jugular vein due to increased flow, and restricting flow in response to sensing the increased flow in the jugular vein.

FIG. 8 shows the restrictor 801 and the pressure sensor 805. Indeed, as shown in FIG. 8, the device 101 includes a pressure sensor 805 along the catheter 105 at locations both proximal and distal to the restrictor 801. In the depicted embodiment, the pressure sensor 805 includes a pressure sensing lumen that extends along the catheter 105 and terminates at a skive cut sensing opening along the side of the catheter 105. The sensing lumen extends proximally along the catheter to the motor housing 401, where the sensing lumen preferably exits the housing 401 and is in fluid contact with a mechanical pressure sensor device, such as a piezoelectric pressure sensor. The interior of the pressure sensing lumen preferably establishes at least substantial hydrostatic equilibrium from the skive cut opening along the side of the catheter 105 to the mechanical pressure sensor device, such that readings from the sensing vise inform of the pressure within the area surrounding the restrictor 801. Thus, the pressure sensor 805 provides information that can be used as information to feed back to the method 701 and control the deployment 717 of the restrictor 801. Method 701 preferably includes, prior to operation 710, step 705 of inserting device 101 having a pump into the patient's vascular system.

9 shows the 705 device 101 inserted into the vasculature of a patient. The device 101 includes a catheter 105 sized to be partially implanted within the vasculature, and the pump includes an impeller assembly 201 disposed on a distal portion 115 of the catheter 105. The distal portion 115 is traced through the jugular vein and inserted into the brachiocephalic vein 939. Preferably, the proximal portion 109 of the catheter 105 is connected to a motor housing 401, and the device 101 includes one or more pressure sensors 805 and a deployable restrictor 801 attached to the catheter 105 proximal to the pump.

Once the impeller assembly is at least partially within the brachiocephalic vein 939, the impeller 205 is rotated to pump blood through the impeller housing 203. This causes a decrease in pressure around the outlet of the lymphatic vessel 907. The decrease in pressure causes lymphatic fluid to drain from the lymphatic vessel 907 into the circulatory system. The drainage of lymphatic fluid reduces edema or alleviates congestive heart failure. The method 701 further includes deploying 717 a restrictor 801 upstream of the impeller assembly 201, thereby restricting flow from the jugular vein to the brachiocephalic vein 939 to balance 729 the pressure downstream of the impeller assembly 201. The method 701 may further include sensing 715 pressure and adjusting 735 the flow restriction according to the pressure sensed 715 via one or more of the pressure sensors 805.

In some embodiments, the restrictor 801 includes an inflatable balloon, and the step of restricting flow 717 includes inflating the restrictor. Optionally, the sensing step 715 is performed using a computer system communicatively connected to the pressure sensor 805. The method 701 may include a step 735 of periodically or continuously adjusting the inflation of the restrictor according to the sensed pressure.

10 illustrates a related method 1001 for treating edema. The method 1001 includes inserting 1005 a pump into the brachiocephalic vein and operating 1010 the pump to increase flow through the patient's brachiocephalic vein 939. A pressure change in the patient's jugular vein due to the increased flow is sensed 1015 and the restrictor 801 is adjusted 1029 to restrict flow from the jugular vein to the brachiocephalic vein 939 based on the sensed pressure. Preferably, the method 1001 includes inserting 1005 a catheter 105 into the brachiocephalic vein 939. The catheter 105 includes a pump, a pressure sensor 805, and a restrictor 801. The restrictor may include an inflatable balloon and adjusting 1029 the restrictor may include at least partially inflating and/or deflating the balloon. The sensing 1015 may be performed using the pressure sensor 805. The method 1001 preferably includes a step of periodically or continuously adjusting the expansion of the restrictor according to the sensed pressure. The method 1001 may include a step 1029 of adjusting the expansion to balance the pressure downstream of the pump. In a preferred embodiment, the pump includes an impeller assembly 201 disposed in a distal portion 115 of the catheter 105. A proximal portion 109 of the catheter 105 is connected to a motor housing 401 having a motor therein operably coupled to the impeller assembly. In an embodiment, the catheter 105 is coupled to a computer system operable to read the pressure or control the expansion.

Aspects and embodiments of the present disclosure relate to purgeless systems, which may be understood to refer to or include methods and devices for the treatment of edema that do not use a purge system or purging liquid.

Figure 11 is a detailed view of features that provide a purge-free system. A purge-free system can be provided by a device 101 including a catheter 105 having a proximal portion 109 and a distal portion 115, an impeller 205 connected to the distal portion 115 of the catheter 105, a motor 405 connected to the proximal portion 109 of the catheter 105, a drive cable 411 extending from the motor 405 through the catheter 105 to the impeller 205, and an impermeable sleeve 121 extending through the catheter 105 over the drive cable 411.

The sleeve 121 has a distal seal 435 at the impeller. Referring back to FIG. 4, the sleeve 121 may have a proximal seal 433 at the motor 405. The sleeve 121 and at least the distal seal 435 prevent bodily fluids outside the impermeable sleeve 121 from entering the impermeable sleeve 121 and contacting the drive cable 411. The sleeve 121 and at least the distal seal 435 exclude fluids from the drive cable 411.

Referring back to FIG. 4, the proximal seal 433 (see FIG. 4) may include one or more O-rings. Similarly, the distal seal 435 between the sleeve 121 and the drive cable 411 may be provided by an O-ring, or a collar, or a press fit, or an extended friction fit tube. Any suitable seal may be included that prevents blood or bodily fluids from entering the sleeve and contacting the drive cable 121. The drive cable 121 may be provided by any suitable material, including, for example, a nickel titanium alloy or a braided steel cable. Contact with blood would present a risk of hemolysis or clotting that could interfere with the ability of the drive cable 411 to rotate freely (e.g., at >5,000 rpm) within the sleeve 121 and within the catheter 105. The sleeve excludes blood, thus eliminating concerns about clotting or hemolysis, and allowing the drive cable 411 and impeller 205 to operate freely without obstruction.

Embodiments of the device 101 may include multiple lumens. For example, the device 101 may include a first and second inflation lumen 415 (or a single inflation lumen 415). The device may include a drug lumen 251 extending through the catheter 105. In a preferred embodiment, the device 101 includes at least a first inflation lumen 415 and a second inflation lumen 415, both of which extend through the catheter 105. The first inflation lumen 415 and the second inflation lumen 415 have respective first and second proximal ends 416 (see FIG. 1) accessible outside the motor housing 401. The first and second lumens are preferably symmetrically positioned about the drive cable 411 to provide balance to the device 101. As shown, the catheter does not include a purge system or purge fluid.

1 and 3, the device 101 may include an impeller 205 seated within an impeller housing 203. The device 101 includes at least a first expandable member 301 connected to a distal portion 115 of the catheter 105. The first expandable member 301 may be connected to the impeller housing 203, and the device 101 further includes a second expandable member 801 disposed along the catheter 105. The first expandable member 301 may use an annular balloon directly connected to a surface of the impeller housing 203. The device 101 may further include at least one pressure sensor 805 disposed along the catheter 105 proximal to the impeller. In a non-purged embodiment, the distal seal 435 can be provided using a fitting 1107 between the impermeable sleeve 121 and a portion of the impeller 205, which excludes fluids and allows the impeller 205 and drive cable 411 to rotate within the device 101. The depicted device 101 is useful for the treatment of edema and can be characterized as a non-purged device. Non-purged devices can be used in methods of treating edema.

12 illustrates a method 1201 of treating edema using a purge-free device. The method 1201 includes the steps of inserting 1205 a distal portion 115 of a catheter 105 into the brachiocephalic vein 939 of a patient and driving 1210 an impeller 205 connected to the distal portion 115 of the catheter 105 with a motor 405 in the proximal portion 109 of the catheter 105. The motor 405 is connected 205 to the impeller by a drive cable 411 extending through the catheter 105, thereby reducing pressure 1217 in the lymphatic vessel 907. An impermeable sleeve 121 extends through the catheter 105 and over the drive cable 411 such that bodily fluids outside the impermeable sleeve are prevented from entering the impermeable sleeve and contacting the drive cable. The impermeable sleeve 121 and at least the distal seal 435 exclude fluid from entering the impermeable sleeve 121 and contacting the drive cable 411 1215.

The method 1201 may include inflating 1229 a restrictor disposed along the distal portion 115 of the catheter 105 to restrict flow from the jugular vein into the brachiocephalic vein 939. Inflating 1229 may be performed with an inflation lumen 415 extending through the catheter 105 outside of the impermeable sleeve 121. In some embodiments, blood and body fluids are excluded 1215 from the drive cable 411 using a repulsive gap between the drive cable 411 and the impermeable sleeve 121. For example, the repulsive gap may include a hydrophobic material (PTFE) on one side of the gap and a smooth metal shaft 411 on the other side, with a gap size that prevents the inflow of blood components. For example, a gap size of about 0.5 μm should prevent the inflow of red blood cells, white blood cells, and platelets. A gap size of 0.1 μm may be found to exclude 1215 all blood and body fluids. Since the drive cable 411 may not be concentric with the sleeve 121, preferably the gap dimension is the maximum gap between the two.

The reduced pressure in the lymphatic duct 907 promotes drainage from the lymphatic system into the circulatory system. Preferably, the impermeable sleeve 121 includes a proximal seal 433 at the housing of the motor 405 and a distal seal 435 at the impeller 205. The proximal seal 433 prevents blood and bodily fluids from escaping the patient through the motor housing 401 or the proximal portion 109 of the catheter 105. In some embodiments, the distal seal 435 includes an attachment between the impermeable sleeve and a portion of the impeller that excludes fluids and allows the impeller and drive cable to rotate within the device 101.

The method 1201 may include inflating at least one balloon 301, 801 disposed along the catheter 105 with an inflation lumen 415 having a proximal end accessible outside the motor housing 401 while the distal portion 115 of the catheter 105 is inserted into the brachiocephalic vein 939. In various embodiments, the proximal seal 433 uses an O-ring, the impermeable sleeve 121 is made of PTFE, the drive cable 411 is made of a metal such as a nickel-titanium alloy, and either or both of the balloon 301 and the restrictor 801 may be made of polyvinyl chloride, cross-linked polyethylene, polyethylene terephthalate (PET), or nylon, or any combination of these materials are included. Employing the method 1201, blood and bodily fluids are excluded 1215 from the drive cable 411 without the use of a purge fluid or purge system.

Other features and benefits are provided by or are within the scope of this disclosure.

The disclosed methods and devices avoid problems with thrombosis or hemolysis that may otherwise interfere with the function of the mechanical system or form surface irregularities that lead to other complications. For example, mechanical systems may be medically most beneficial when blood clots or other clotting-related phenomena are avoided. Thus, embodiments of the disclosed devices and methods are provided that prevent clotting, thrombosis, hemolysis, or other problems that may exist when treating edema.

Certain embodiments provide devices that operate with benefit from an anticoagulant. The device may include a pump (e.g., an impeller assembly) that is flushed with a solution or suspension of an anticoagulant, such as heparin. If the pump or impeller assembly is provided via a catheter, the catheter may include a lumen, reservoir, port, or other such feature for releasing the anticoagulant at or near the pump.

13 illustrates a portion of an intravascular device 101 for the treatment of edema that releases an anticoagulant in an intravascular pump. The device 101 includes a catheter 105, an impeller assembly 201 mounted to a distal portion 115 of the catheter 105, and a drug lumen 251 extending through the catheter 105 and substantially terminating at an inlet 255 of the impeller assembly 201. When the device 101 is in use (e.g., when the impeller 205 is operated within a patient's blood vessel), drug released from the drug lumen 251 flows through the inlet 255 and the impeller assembly 201. Preferably, the catheter 105 and impeller assembly are sized for insertion through the patient's jugular vein. The device 101 may include a reservoir in fluid communication with the drug lumen 251. The reservoir can be, for example, a solution bag (also known as an "IV bag") located on a rack near the treatment gurney and in fluid communication with the drug lumen 251 (e.g., via a Luer lock).

In one embodiment of the anticoagulant delivery device 101, the impeller assembly 201 has an impeller housing 203 with an impeller 205 rotatably disposed therein. The device 101 preferably includes a motor 405 connected to the proximal end of the catheter 105 and operably connected to the impeller 205 via a drive cable 411 extending through the catheter 105. The drug lumen 241 preferably extends through the catheter 105 (e.g., outside of the sleeve 121 surrounding the drive cable 411) and may terminate in a port 252 such that anticoagulant released therefrom flushes the impeller 205 or the impeller assembly 201. Preferably, the port 252 is located in the impeller housing 203 proximal to the impeller.

To define the inlet 255, the catheter 105 may include a tube with a drive cable extending therethrough, with a cap 249 connected around the distal portion of the tube, and the impeller housing 203 is mounted to the cap by a number of struts to define the inlet 255 into the impeller housing 203. In some embodiments, the cap 249 seals the distal end of the flexible tube to the shaft of the impeller, and the port 252 is located in the cap 249. Preferably, the impeller housing includes one or more outlets 258 around the distal portion 115 of the impeller, such that operation of the impeller 205 within the blood vessel drives blood into the impeller assembly 201 via the inlet 255 and out of the impeller assembly via the outlet 258.

The device 101 may include an anticoagulant in the reservoir. When the device 101 is inserted into the patient's blood vessel and the impeller 205 is operated, the anticoagulant is released from the port 252 in the impeller cage 201, and the released anticoagulant mixes with the blood and overflows over the rotating impeller 205. Any suitable anticoagulant may be used. For example, the anticoagulant may include one or any combination of heparin, tirofiban, warfarin, rivaroxaban, dabigatran, apixaban, edoxaban, enoxaparin, and fondaparinux. Due to the anticoagulant, the device 101 may be used for the treatment of edema using the impeller to cause lymphatic or vascular drainage.

Using such a device, aspects of the invention provide a method of treating edema. The method includes operating a pump to increase flow through the patient's brachiocephalic vein 939 and releasing an anticoagulant at or adjacent to the inlet of the pump. The pump may include an impeller 205 within a cage 203 in a distal portion 115 of the catheter 105, and the anticoagulant is released from a port 252 in or adjacent to a proximal portion of the cage. Preferably, the proximal end of the catheter 105 terminates in a housing that includes a motor 405, which is operably coupled to the impeller by a drive cable extending through the catheter 105. In the method, the catheter 105 includes a drug lumen extending therethrough and terminating in a port. The method may include providing an anticoagulant in a reservoir in fluid communication with the drug lumen, inserting a catheter 105 into the patient's vascular system and positioning an impeller in the brachiocephalic vein 939, operating a motor 405 to drive the impeller, and overflowing the anticoagulant over the impeller by releasing the anticoagulant from a port. Preferably, the method includes operating a pump to reduce pressure in the lymphatic vessel 907, thereby draining lymphatic fluid from the patient's lymphatic system. The pump may include an impeller on a distal portion 115 of the catheter 105. The method may include releasing the anticoagulant from a 109 port in a proximal portion of the impeller, preventing clots or thrombosis from interfering with the operation of the impeller by releasing the anticoagulant, or both. The anticoagulant may include heparin, warfarin, rivaroxaban, dabigatran, apixaban, edoxaban, enoxaparin, or fondaparinux. Using the restrictor 801, 301, the method may include restricting flow from the jugular vein to the brachiocephalic vein 939, thereby facilitating flow from the subclavian vein to the brachiocephalic vein 939.

FIG. 16 is a partial cutaway view of an impeller assembly 1601. The impeller assembly 1601 includes an impeller housing 1603 with an impeller 1605 rotatably disposed therein. An expandable member 1607 is attached to the exterior of the impeller housing 1603. The expandable member 1607 is depicted in an expanded state.

The impeller assembly 1601 may be designed to promote blood flow through the impeller housing 1603. To promote blood flow, the impeller housing 1603 may include a proximal inlet 1655. Preferably, the impeller housing 1603 includes at least four proximal inlets 1655. The proximal inlets 1655 may be generally rectangular and may include rounded corners. The impeller assembly 1601 may also include a distal outlet 1658. For example, the impeller assembly 1601 may include four to five distal outlets 1658. Preferably, the proximal inlet 1655 and the distal outlet 1658 include generally rounded features, such as rounded corners. Rounded features are preferred because they provide a smooth contact surface for blood flowing through the impeller housing 1603. This can reduce the occurrence of particles in the blood, such as damage to blood cells, that occur when blood strikes a sharp surface.

In a preferred embodiment, the expandable member 1607 is attached to an outer surface of the impeller housing 1603. The expandable member 1607 may have a shape that promotes blood flow into the impeller housing 1603 when the expandable member 1607 is in an expanded state. In some embodiments, the expandable member 1607 forms a D-shaped ring around the circumference of the impeller housing 1603. In other embodiments, the expandable member 1607 forms an omega-shaped ring around the circumference of the impeller housing 1603. In other embodiments, the expandable member 1603 forms a generally circular ring around the impeller housing 1603.

In the expanded state, the proximal surface 1613 of the expandable member 1607 can be substantially aligned with the distal portion 1615 of the proximal inlet 1655. The distal surface 1617 of the expandable member 1607 can be substantially aligned with the proximal extent 1619 of the distal outlet 1658.

In a preferred embodiment, the expandable member 1607 comprises an elastomeric membrane, e.g., a polyurethane membrane. The expandable member 1607 can be a balloon. The balloon can be made of a low durometer material, e.g., a durometer of <80 Shore D, or <70 Shore D, or less than 60 Shore D, or between 60 Shore A and 60 Shore D.

The expandable member 1607 may include a fluidly sealed space, i.e., an expansion space 1623, that is radially expandable relative to the impeller housing 1603. The impeller assembly 1601 may include an inflation tube 1627 that connects the expansion space 1623 to a lumen of the catheter 1602. The inflation tube 1627 may extend between the catheter 1602 and the expansion space 1623, for example, parallel to the proximal strut 1633. The inflation tube 1627 may extend external to the proximal strut 1633 (as shown). Alternatively, the inflation tube 1627 may extend internal to the proximal strut 1633. The inflation tube 1627 may connect to the expansion space 1623 by extending through a wall of the expandable member 1607. Alternatively, the inflation tube 1627 may connect to the expansion space 1623 by extending through an interface between the expandable member 1607 and the impeller housing 1603 or by extending through a wall of the impeller housing 1603. The fluidly sealed space 1623 may include an inflation port for expanding the expandable member 1607.

The inflation tube 1627 may include an outer surface and a lumen. The inflation tube 1627 preferably provides a sealed penetration into the expansion space 1623. The penetration of the inflation tube 1627 into the expansion space 1623 may include sealing in the area of the penetration. The sealing may include a melting or bonding operation.

17 is a side view of the impeller assembly 1701. An expandable member 1707, e.g., a balloon, is attached to the outer surface of the impeller housing 1703. The expandable member 1707 may be generally toroidal in shape. The expandable member 1707 is depicted with low-profile lines to reveal the structure beneath the expandable member 1707. A proximal surface 1713 of the expandable member 1707 extends across a distal inlet region 1715. In this configuration, the proximal surface 1713 of the expandable member 1707 provides a funnel to converge blood flow toward the inlet of the impeller housing 1703, thereby facilitating blood flow through the device.

The impeller assembly 1701 is dimensioned for insertion into the brachiocephalic vein. The expandable member 1707 is dimensioned such that in a deployed state, the expandable member 1707 faces the wall of the brachiocephalic vein and impedes, induces, or directs blood flow into the impeller housing 1703. In some embodiments, the inner diameter of the expandable member 1707 is substantially equal to the outer diameter of the impeller housing 1703. The inner diameter of the expandable member 1707 may extend over a portion of the proximal inlet. This arrangement helps direct blood into the impeller assembly 1701 without the distal edge of the inlet impeding blood flow. In some embodiments, the proximal inlet is generally D-shaped with rounded features to prevent shearing of blood cells.

The expandable member 1707 may include a bonded region that includes a generally cylindrical section where the expandable member 1707 is bonded to the impeller assembly 1701. In some embodiments, the inlet region may include a conical element 1737 that is coaxial with the impeller. The conical element 1737 may be proximal to the impeller and configured to minimize flow recirculation regions.

18 shows an exemplary inlet region 1855 of the impeller assembly 1801. The inlet region 1855 includes a conical element 1837 with flow directing features protruding radially outward from a surface of the conical element 1837. The flow directing features may be aligned with the proximal post. A drive element 1839 may extend through the conical element 1837 and connect with an impeller disposed inside the impeller assembly 1601. In the embodiment shown, the inflation lumen 1827 is external to the impeller assembly 1801.

FIG. 19 shows an inlet region 1955 with an internal inflation lumen. The inflation lumen is internal to the impeller housing 1903. The inflation lumen may connect to and extend through the cone-shaped element 1937. The inflation lumen may extend, for example, through a wall of the impeller housing 1903. Alternatively, the inflation lumen may be located internally within the impeller housing 1903.

20 is a detailed view of the proximal inlet 2055. The proximal inlet 2055 is defined by proximal struts 2033. The proximal struts 2033 extend parallel to one another and connect the proximal portion 2041 of the impeller housing 2003 to the distal portion 2043 of the impeller housing 2003. The proximal struts 2033 are designed such that when the catheter is operating inside the patient's body, the proximal struts 2033 can separate and direct blood flow into the impeller housing 2003 without inducing a recirculation flow pattern. The proximal struts 2033 can include proximal and distal perimeters 2045, 2047. The proximal struts 2033 and perimeters 2045, 2047 can define, for example, a generally rectangular inlet region 2055. In some embodiments, the generally rectangular inlet region 2055 comprises a curvilinear rectangular inlet. The curved rectangular inlet may, for example, have a bevel around at least a portion of the periphery 2045, 2047 of the inlet 2055. The bevel may provide a gradual transition area for blood to enter the impeller housing 2003.

In some embodiments, the proximal struts 2033 include a substantially constant width along the length of the proximal struts 2033. In other embodiments, the width of the proximal struts 2033 may vary, e.g., the width of the proximal struts 2033 may be greater at the proximal end than at the distal end, or vice versa. The proximal struts 2033 may include a first wall thickness and a second wall thickness, the first wall thickness being greater than the second wall thickness. In some embodiments, the proximal struts 2033 may include a tapered wall thickness.

Preferably, the impeller housing 2003 is generally cylindrical in shape for easy passage through the brachiocephalic vein. The impeller housing 2003 may include multiple inner diameters for manipulating the blood flow through the impeller housing 2003 such that the blood flow experiences minimal disturbances, such as recirculation or vortices, within or near the impeller assembly 2001. For example, the impeller housing 2003 may include a first inner diameter D1 and at least a second inner diameter D2, the first inner diameter being greater than the at least second diameter. In some embodiments, the impeller housing 2003 may include a stepped portion defined by a change in inner diameter. In some embodiments, the impeller housing 2003 may include a tapered diameter, defined by, for example, a decreasing or reduced inner diameter along the length of the impeller housing 2003 toward one end.

FIG. 21 shows a side view of the impeller assembly 2101 with a rectangular proximal inlet 2155. This configuration may reduce blood recirculation in the proximal area of the impeller assembly 2101 by providing a larger inlet area at the distal-most region of the inlet 2147.

22 illustrates an impeller assembly 2201 with an arcuate proximal strut 2233. The arcuate proximal strut 2233 extends longitudinally and radially. In some embodiments, the arcuate proximal strut 2233 comprises a tubular member. The tubular member may be welded to the impeller assembly 2201, connecting the proximal portion 2241 of the impeller housing 2203 to the distal portion 2243 of the impeller housing 2203. The arcuate proximal strut 2233 may be connected to the proximal portion 2241 of the impeller housing 2203 integrally with the catheter shaft. The arcuate proximal strut 2233 may comprise a monolithic structure. The monolithic structure may comprise a 3D printed structure.

The impeller assembly 2201 may be mounted distally to a catheter shaft (not shown) that includes multiple lumens, at least one of which is sealingly connected to an expandable member 2207 attached to the outer surface of the impeller housing 2203.

23 shows a side view of the proximal portion of the impeller assembly 2301. The proximal portion of the impeller assembly 2301 includes a proximal hub 2383, a proximal inlet 2355, and a body section 2385. The proximal hub 2383 can be configured to promote a smooth flow pattern as fluid, e.g., blood, is directed into the proximal inlet 2355. The hub 2383 can include a generally circular outer geometry in axial cross section for easy movement within the vein. The hub 2383 can include a tapered geometry. For example, a cross-sectional diameter of the hub 2383 can decrease along the length of the hub 2383 from a first end to a second end. The hub 2383 may have a tapered outer geometry that may include a proximal diameter, an intermediate diameter, and a distal diameter, where the intermediate diameter is greater than either the proximal or distal diameter, and the transitions between the proximal, intermediate, and distal diameters are generally smooth. The curves between the proximal, intermediate, and distal diameters may not involve inflection points.

FIG. 24 illustrates an impeller assembly 2401. The impeller assembly 2401 includes an impeller housing 2403 with an impeller 2405 rotatably disposed therein. An expandable member 2407, depicted in phantom, is attached to an outer surface of the impeller housing 2403, the expandable member 2407 being shown in an expanded state.

The impeller assembly 2401 is designed to promote blood flow through the impeller housing 2403. The impeller assembly 2401 includes fillets 2435 under the proximal ends of the proximal struts 2433 to provide mechanical support and may prevent recirculation of blood in these areas when the catheter is inside the vein. In some embodiments, the proximal struts 2433 taper toward their distal ends.

FIG. 25 shows an elongated impeller assembly 2501. The elongated impeller assembly 2501 includes an expandable member 2507 spaced from a proximal entrance region 2555. The expandable member 2507 can be, for example, about 1-25 cm from the proximal entrance region 2555. Preferably, the expandable member is at least 1 cm from the proximal entrance region 2555.

26 shows a cross-sectional view of an impeller assembly 2601. The impeller assembly 2601 includes an impeller housing 2603 with an impeller 2605 rotatably disposed therein. The impeller assembly 2601 includes a distal portion 2645. The distal portion 2645 can include a tip 2647 that is generally disc-shaped. The distal portion 2645 can have an at least partially flat surface. The disc-shaped tip 2647 can be spaced from a proximal surface of the distal portion 2645.

The impeller 2605 may have a substantially fixed axial position relative to the impeller housing 2603. The distal portion 2645 may have a substantially fixed axial position relative to the impeller housing 2603. The fixed axial positions of the impeller 2605 and the distal portion 2645 may define a distal gap 2651 between the distal portion 2645 and the impeller 2605. The gap 2651 is preferably greater than 5 μm. The gap 2651 may be greater than 10 μm or 20 μm. The gap 2651 may preferably be less than 150 μm, 120 μm, or 100 μm. Ideally, the gap 2651 is between 25 μm and 50 μm.

Figure 27 is a cross-sectional view of the impeller assembly 2601 inside a vein 2756. The impeller assembly 2701 includes an impeller housing 2703 with an impeller 2705 inside. The impeller housing 2703 has an expandable member 2707 attached to an outer surface of the impeller housing 2703.

The impeller 2705 includes at least one blade 2753. The blade 2753 has a proximal end and a distal end. The core diameter of the impeller 2705 has a proximal end and a distal end. The core diameter proximal end is proximal to the proximal end of the blade 2753. The core diameter distal end and the blade distal end terminate at substantially the same axial region. The core diameter is smallest at the proximal end of the impeller 2705 and largest near the distal end of the core diameter. The core diameter may include a curved tapered surface.

The proximal end of the impeller 2705 core diameter can be spaced from the distal end of the cuff 2761. The proximal end of the impeller 2705 core diameter and the distal end of the cuff 2761 have a controlled proximal gap. The gap 2751 is preferably greater than 5 μm. The gap 2751 can be greater than 10 μm or 20 μm. The gap 2751 can preferably be less than 150 μm, 120 μm, or 100 μm. Ideally, the gap 2751 is between 25 μm and 50 μm.

The impeller 2705 may include an inner diameter that extends through at least a portion of the length of the impeller 2705 and is coaxial with the impeller 2705. The impeller 2705 may include a bearing arrangement distal to a distal surface. The bearing surface may include a ball bearing arrangement, e.g., a ceramic bearing arrangement, or a PTFE or PEEK bearing surface arrangement.

Figures 28A-F illustrate the attachment and folding of the expandable member 2807. In particular, these figures detail the attachment of the expandable member 2807 to the outer surface of the impeller housing 2803 and the folding of the expandable member 2807 when it is inflated or when the catheter is being delivered or retrieved.

FIG. 28A is a partial cross-sectional view of the impeller assembly 2801. The portion of the cross-section bounded by the dashed line and labeled B shows a portion of the expandable member 2807 and is enlarged in FIG. 28B. The expandable member 2807 includes at least one coupling 2863 that attaches the expandable member 2807 with the impeller housing 2803. The coupling 2863 can create a sealed annular space within the expandable member 2807.

The joint 2863 may comprise a laser welded joint, a solvent welded joint, an adhesive welded joint, a hot air or heated surface welded joint, or any other similar type of attachment. The joint 2863 may comprise a prepared outer surface of the impeller housing 2803 onto which the expandable member 2807 is attached. For example, the impeller housing 2803 may be prepared such that the impeller housing 2803 includes at least one of a primed surface, a chemically activated surface, a plasma activated surface, a mechanically polished surface, a laser ablated surface, and an etched surface, or a textured surface. The prepared outer surface of the impeller housing 2803 may comprise a surface roughness, a patterned surface, or a high energy surface.

28B, the expandable member 2807 may include at least one reduced diameter section 2867, which may be dimensioned to mate with the impeller housing 2803. The expandable member 2807 may include a fitting distal end 2831 and a fitting proximal end 2832. The shape of the distal end 2831 may be configured to change as the expandable member is inflated/deflated (compare FIGS. 28B, 28D, and 28E) or when the catheter is moved inside the vein. In particular, the fitting distal end 2831 may include a distal reduced diameter section that is joined to the impeller housing 2803 and a distal transition section 2845 that is integral with the reduced diameter section 2867 but not attached to the impeller housing 2803. As the expandable member 2807 is inflated, the distal transition section 2867 may fold inward. The fitting proximal end may include a reduced diameter section 2832 joined to the impeller housing 2803 and a proximal transition section integral with the reduced diameter section but not attached to the impeller housing. The expandable member 2807 may be configured to be substantially rigid in the expanded configuration. The expandable member 2807 may be configured to be conformable in the expanded configuration. The expandable member 2807 may be made from a polyurethane, or Pebax, or nylon material. The expandable member 2807 may be made from polytetrafluoroethylene.

Figure 28C is a partial cross-sectional view of the impeller assembly 2801 with the expandable member 2807 partially expanded. A portion of the partial cross-sectional view (labeled D) showing the expandable member 2807 is enlarged in Figure 28D. Notably, the shape of the distal neck down changes as the expandable member 2807 is expanded (compare Figure 28D, where the expandable member is partially expanded, to Figure 28B, where the expandable member is fully expanded).

28E is a partial cross-sectional view of the impeller assembly 2801 with the expandable member 2807 moderately inflated. A portion of the partial cross-sectional view (labeled F) showing the expandable member 2807 is enlarged in FIG. 28F. Notably, the expandable member 2807 is more inflated than the expandable member 2807 illustrated in FIG. 28D. In response to inflating the expandable member 2807, the distal transition section 2845 may fold outward, eliminating a potential recirculation zone at the interface between the balloon and the housing 2803.

29 shows an impeller assembly 2901 with an expandable member 2907 having an elongated surface 2974 for interfacing with the vessel wall. The elongated surface 2974 increases the interaction between the vessel and the impeller assembly 2901 and limits the movement of the impeller assembly inside the vessel. The expandable member 2907 can be made of a flexible material. The flexible material can be polyurethane or silicone. The flexible material can stretch 100%-800% thus creating the elongated surface 2974. In other embodiments, the expandable member 2907 can be made of a non-compliant material that can expand to one specific size or size range even with increased internal pressure.

FIG. 30 shows an impeller assembly 3001 with a two-part expandable member 3007. The two-part expandable member 3007 includes a first part 3065 made of a flexible material and a second part 3066 made of a non-compliant material. The first part 3065 and the second part 3066 can be attached to each other and to the impeller housing 3003 to define an annular space for expansion. Preferably, the first part 3065 of the expandable member 3007 comprises the portion of the expandable member 3007 that interacts with the blood vein wall during operation of the catheter.

31 is a partial cross-sectional view of a distal portion of the catheter 3101. The distal portion of the catheter 3101 is attached to the impeller housing 3103 with an expandable member 3107 mounted to the outer surface of the impeller housing 3103. The impeller housing 3103 is connected to the distal portion of the catheter 3101 by a number of proximal struts 3133. The proximal struts 3133 are preferably made of a flexible material, such as latex, silicone, or Teflon, to provide easier navigation inside the patient's vein. The proximal struts 3133 may be configured to conform to anatomical curvatures. A drive shaft 3139, which connects the motor to the impeller disposed inside the impeller housing 3103, may comprise a flexible drive cable.

32 is a partial cross-sectional view of a self-expanding impeller assembly 3201. The impeller assembly 3201 includes an impeller housing 3203 with an impeller 3205 disposed therein. An expandable body 3207 is attached to a surface of the impeller housing 3203 between a proximal inlet 3255 and a distal outlet 3258.

In the expanded configuration, the expandable body 3207 is configured to face the venous wall across a longitudinal section of the vein. The longitudinal section of apposition extends proximal to the proximal inlet 3255. The longitudinal section of apposition extends distal to the distal inlet 3258. The expandable body 3207 is configured to provide a proximal flow-directing funnel extending from the region of apposition with the vessel wall to the distal end of the inlet 3255. The proximal flow-directing funnel is configured to promote a converging flow pattern at the ingress to the proximal inlet 3255. The expandable body 3207 can be configured to provide a distal flow-directing leak extending from the proximal region of the outlet 3258 to the distal end of the outlet 3258 from the region of apposition with the vessel wall to the distal end of the inlet 3255. The distal flow-directing funnel can be configured to promote a diverging flow pattern at the exit of the outlet 3258. The divergent flow pattern can be configured to provide a gradual deceleration of the fluid distal to the outlet to reduce recirculation, or to maintain a greater percentage of the pressure gain exerted by the impeller 3205 through a negative velocity flow pattern.

The expandable body 3207 may comprise a nitinol membrane, a non-compliant membrane, or a porous membrane. The longitudinal sections of the expandable body 3207 may be made of a compliant material. Preferably, the flow-directing funnels of the expandable body 3207 are made of a relatively less compliant material (or a semi-compliant or non-compliant material).

The catheter 3200 may include a plurality of pull wires 3279 attached to the expandable body 3207 and facilitating collapse of the expandable body 3207 in preparation for removal of the catheter 3200 from the body.

33 shows a partial cross-sectional view of the impeller assembly 3301. The impeller assembly 3301 includes a proximal strut 3333 that attaches a proximal portion 3341 of the impeller assembly 3301 to a distal portion 3343 of the impeller assembly 3301. At least one proximal strut 3333 includes an inflation lumen, i.e., an integral inflation channel, that extends through the proximal strut 3333 and into the interior of an expandable member 3307 that is attached to the outer surface of the impeller assembly 3301. The inflation lumen provides a structure for inflating the expandable member 3307. The inflation lumen is preferably terminated in an inlet to minimize interference with flow inside the housing. This is facilitated by the expandable member 3307 being positioned more proximally.

34 shows the inlet 3433 of the impeller assembly 3401. The inlet 3433 is configured to provide easier fluid flow into the assembly 3401. The configuration includes a proximal hub 3480 with at least one flow area 3481. The flow area 3481 extends from a proximal region of the proximal hub 3480 and terminates at the inlet 3433. The flow area 3481 extends between the first and second struts 3433, 3434. The flow area 3481 can be configured to modulate blood flow upstream of the inlet. For example, the flow area 3481 can be gradually angled inward along the length of the flow area 3481 toward the inlet 3433.

35 is an exemplary catheter system 3500. In particular, FIG. 35 illustrates a catheter 3500 in accordance with aspects of the present invention, showing the interaction between an impeller assembly 3501 of the catheter 3500 and a vessel wall 3556. The catheter 3500 includes an impeller assembly 3501, a catheter shaft 3581, a proximal expandable member 3508, a hub 3583, and a motor (not shown).

The impeller assembly 3501 is dimensioned for placement inside a blood vessel with a shaft 3581 extending from the impeller assembly 3501 to a location external to the patient. The shaft 3581 may comprise a multi-lumen shaft. A first proximal expandable member 3508 is attached to the shaft 3581 and may be configured to restrict blood flow to the impeller assembly 3501.

A motor may be connected to the impeller housed within the impeller assembly 3501 and configured to drive the impeller at high RPM. The impeller assembly 3501 may include a distal expandable member 3507 mounted on an outer surface of the impeller housing 3503 and wrapped around the impeller housing 3503, e.g., as an expandable ring. The distal expandable member 3503 may be configured to appose the vessel wall 3556 during operation of the catheter.

The proximal expandable member 3508 may be mounted on the catheter shaft 3581 proximal to the impeller assembly 3501. The proximal expandable member 3508 may be spaced apart from the impeller assembly 3501. For example, the proximal expandable member 3508 may be a distance of 1-10 cm, preferably about 5 cm or less, upstream of the impeller assembly 3501.

The proximal expandable member 3508 may be sized for placement (inflation) between the vascular access site and the outflow port of the thoracic duct 3585. The expandable members 3507, 3508 are preferably configured to atraumatically contact the vessel wall.

In some embodiments, the proximal expandable member 3508 may be configured to reduce the volume of blood flowing in the vessel by impeding blood flow. The proximal expandable member 3508 may be configured to regulate the volume of blood flowing in the vessel by impeding, restricting, directing, or guiding blood flow. For example, the proximal expandable member 3508 may include an orifice for fluid to flow across the expandable member 3508 while the expandable member 3508 is in an expanded state. For example, the orifice may comprise substantially one of an annular ring or a crescent shape with a lumen through the body of the expandable member 3508. The orifice may comprise a valley or recess in the outer surface of the expandable member 3508. The orifice may comprise a channel beneath the expandable member 3508. The expandable member 3508 may comprise a shape that defines the orifice. For example, the expandable member 3508 may be shaped at least partially as a sphere, cone, or cylinder, and the orifice may comprise an annular ring or crescent shape. The shape of the expandable member 3508 may comprise, for example, a double D-shape, and the orifice may be defined by a surface between two mating shapes. The expandable member 3508 may comprise a helix wound around the catheter shaft 3581, and the orifice may comprise a channel defined by a space between adjacent helices.

The proximal expandable member 3581 can be comprised of a flexible material, which can have a flexibility-pressure relationship. The expandable member 3581 can be processed so that the flexibility-pressure relationship is repeatable. The expandable member 3581 can comprise an annealed member. The expandable member 3581 can be configured to achieve a precise diameter at a given pressure. The expandable member 3581 can be configured to have minimal hysteresis when expanded, contracted, and re-expanded.

The hub 3583 may be configured to facilitate expansion of the distal expandable member 3507 and may be configured to at least partially expand the proximal expandable member 3508. For example, the hub 3583 may include access to one or more lumens that extend through the catheter shaft 3581 and connect to the proximal and/or distal expandable members 3508, 3507. The expandable members can be expanded by injecting fluid into the lumens at the hub 3583. The hub 3583 may be configured to expand the proximal expandable member 3508 into apposition with the brachiocephalic vessel.

The device may include a connector cable 3585 configured to connect the catheter to a console (not shown), which may include a computer with hardware, software, and a user interface. The console may be configured to operate the device.

FIG. 36 shows a catheter 3600 with an expandable member 3608 slidably mounted along a shaft 3681 of the catheter 3600. The catheter 3600 comprises a first catheter shaft 3681 and a second catheter shaft 3682. The catheter 3600 includes an impeller assembly 3601 attached to the distal end of the first catheter shaft 3681. A proximal expandable member 3608 is mounted near the distal end of the second catheter shaft 3682.

The first catheter shaft 3681 may include multi-lumen tubing with a first lumen configured to facilitate expansion of the distal expandable member 3607 and a second lumen configured to transmit mechanical or electrical energy to facilitate operation and control of an impeller disposed within the impeller assembly 3601.

The second catheter shaft 3682 may comprise multi-lumen tubing with a first lumen configured to encapsulate the first catheter shaft 3681 and a second lumen configured to inflate the proximal expandable member 3608. The first and second catheter shafts 3681, 3682 may be configured to facilitate relative axial movement (indicated by arrows) between the distal expandable member 3607 and the proximal expandable member 3608. The relative axial movement may be limited distally. The relative axial movement may be limited proximally. The catheter 3600 may include a first stop and a second stop, and the axial movement of the second shaft 3682 may be limited by the first and second stops. The first and second stops may be mounted on the first shaft 3681 external to the patient (inside or around a hub). The axial movement may include fine movement. The fine movement may include, for example, a screw thread or a ratchet mechanism.

The relative axial movement between the distal expandable member 3607 and the proximal expandable member 3608 may provide better anatomical placement, i.e., accurate placement of the distal expandable member 3607 in the brachiocephalic vein and then accurate placement of the proximal expandable member 3608 between the vessel wall access site and the thoracic duct.

The first and second shafts 3681, 3682 may extend outside the patient. The second shaft 3682 may be coupled and decoupled to the first shaft during use. In the collapsed state, the catheter may be sized for advancement through the lumen of the valve and sheath. The second shaft 3682 may include a distal section and a proximal section. The distal section may include a tubular member and an inflation lumen, with the proximal expandable member hermetically welded (joined) to the distal section to create an inflation space within the expandable member 3607 in fluid communication with the inflation lumen.

The proximal section of the second shaft may include an inflation lumen and a member configured to transmit axial pushing and pulling forces to the distal section of the second shaft 3682. The proximal section of the second shaft may be concentric or eccentric with the first shaft. The inflation lumen of the proximal section may be integral with the wall of the proximal section of the second shaft.

37 shows a fluid channel traversing the expandable member 3708 that allows for a controlled amount of blood flow. The proximal expandable member 3708 can be configured to face the vessel wall. The proximal expandable member 3708 can include a flow channel 3706 that defines a lumen through the body of the expandable member 3708. The flow is indicated by the black arrows. The flow channel 3706 can include a collapsed state and an expanded configuration. The flow channel 3706 can be configured to expand when the expandable member 3708 is inflated. The expandable member 3708 can include at least one inner membrane that can be configured to support the body flow channel 3706 in the expanded state. The proximal expandable member 3708 can be configured to allow 100 ml or more of fluid per minute to traverse the expandable member 3708.

38 shows a catheter 3800 with an alternative bypass channel 3806. The second shaft 3882 comprises a tubular member with a distal end and a proximal end and a lumen 3883 extending through both the distal and proximal ends. The lumen 3883 can be sized to provide a fluid flow path under the inflated expandable member 3808 in the distal section. The second shaft 3882 can comprise an entry port 3885 at the proximal end of the distal section of the second shaft 3882, which can be configured to facilitate blood flow into the fluid flow path.

Figure 39 shows a patient interface 3900 with a sheath 3904 in situ. A proximal expandable member, flow entry ports, and a pressure sensor may be on the sheath. The catheter system may include a catheter and a flow control sheath 3904, the catheter including an impeller assembly at the distal end of an elongated shaft, the flow control sheath 3904 including a flow restrictor, a fluid channel, and a pressure sensor.

The system may be configured for percutaneous insertion into a vein of a patient 3908. Insertion of the catheter includes percutaneous insertion in the region of the jugular vein. The flow control sheath 3904 may be configured for placement to provide an access platform for other components of the system. The flow control sheath 3904 may include a flow restrictor adjacent a tip. The flow restrictor may include an expanded state and a collapsed state. In the collapsed state, the flow restrictor may be configured to collapse completely onto the shaft of the sheath. In the collapsed state, the OD of the flow restrictor may be substantially the same as the shaft of the sheath. The restrictor may seat within an annular recess within the diameter of the shaft of the flow control sheath in the collapsed configuration. In the expanded configuration, the flow restrictor may be configured to at least partially restrict fluid flow through the jugular vein. The flow restrictor may be configured to control the flow rate through the jugular vein. The flow restrictor may be configured to prevent inadvertent displacement of the flow control sheath during the procedure.

The flow control sheath may include a pressure sensor, which may be configured to measure pressure in the vein upstream of the restrictor. The sheath may include a lumen in a wall of the sheath, and the pressure sensor may be positioned in the lumen. The pressure sensing lumen may include a port, which may be configured to establish a hydrostatic connection between blood in the vein and the pressure sensor. The pressure sensor and pressure sensing lumen may be sized to prevent blood flow ingress into the pressure sensing lumen.

FIG. 40 shows a patient interface 4000 with a sheath 4004 held in place by an adhesive membrane 4010. The adhesive member 4010 helps maintain a sterile field around the access site and secures the hub 4080 of the sheath 4004 to the skin. This reduces irritation to the patient from movement of 4080 caused by accidental forces. The membrane 4010 can be shaped to allow for second or third layers to be added, tying all of the various system elements of the sheath 4004 or catheter together or to the skin.

FIG. 41 illustrates a flow control sheath 4150. Shown are various features of the flow control sheath 4150, according to several preferred embodiments. In particular, the flow control sheath 4150 may include a restrictor 4151 (shown in an inflated state), a sheath tip 4152, a port 4153, a pressure sensor 4154, a sheath shaft 4155, and a hub 4159 including a pressure sensor lead 4156, an inflation side port 4157, and an irrigation and injection side port 4158. At least one suture hole may be added to the hub 4159 to facilitate fixation to the patient.

Figure 42 shows the proximal portion of the catheter system 4200. A catheter 4269, similar to the catheter described in Figure 40, is disposed within a catheter sheath 4280. The catheter 4269 includes a shaft 4270, a proximal expandable member 4271 (depicted in an expanded state), and a catheter pressure sensor 4273. The sheath 4280 includes a sheath tip 4272, a sheath pressure sensor 4274, a sheath shaft 4275, a pressure sensor lead 4276, an inflation port 4277, and a hub 4278.

FIG. 43 illustrates a locking mechanism 4300 for securing the catheter shaft 4392 to the hub 4391 of the sheath 4390 during therapy. The locking mechanism 4300 includes an arm 4396 with a catheter shaft grip 4395 attached to the distal end of the arm 4396. When engaged, the catheter shaft grip 4395 attaches to the catheter shaft 4392 and prevents migration. The locking mechanism 4300 is advantageous because it prevents migration of the distal expandable member of the catheter system described above during therapy. The locking mechanism 4300 is configured to lock the catheter shaft 4392 to the sheath 4390 during at least a portion of the procedure.

The locking mechanism 4300 may be configured for easy engagement and disengagement. The locking mechanism may be configured to prevent relative movement between the catheter distal balloon and the access sheath 4390. The locking mechanism 4300 may include a clip 4395 on the locking mechanism 4300, which may be configured to clip onto the catheter shaft 4392 from one side of the shaft 4392. The locking mechanism 4300 may be pre-loaded onto the catheter shaft 4392 such that the locking mechanism 4300 may slide into place when fixation is required.

The locking mechanism may be integral with the sheath. Optionally, the locking mechanism may be attached to the sheath. Preferably, the locking mechanism may be a Tuohy Borst type locking mechanism.

Figure 44 shows the locking mechanism 4300 engaged with the catheter shaft.

Figure 45 shows a schematic diagram of the push lock mechanism 4500.

FIG. 46 shows an alternative locking mechanism 4600. The locking mechanism 4600 includes an arm 4696 attached to a hub 4691 of a sheath 4690. The arm 4696 includes a catheter shaft grip 4695 attached to a distal end of the arm 4696. When engaged, the catheter shaft grip 4695 attaches to the catheter shaft 4692 and prevents migration. A further embodiment of the locking system may include a C-shaped shaft that may be secured over the catheter shaft proximal to the sheath. The shaft would be configured to create an interference fit between the catheter shaft OD and the sheath ID when the shaft is slid into the sheath hub.

FIG. 47 is a partial cutaway view of the jugular vein 4752 showing the flow control sheath 4750 inserted therein. The restrictor 4751 of the sheath 4750 is shown in a deployed state with the restrictor 4751 facing the wall of the jugular vein 4752. In a preferred position, the shaft 4755 of the sheath 4750 terminates adjacent the junction of the subclavian vein 4753 and the thoracic duct 4756. The hub 4759 is external to the jugular vein 4752.

FIG. 48 illustrates an indwelling catheter system 4800 in accordance with an aspect of the present invention. The indwelling catheter system 4800 includes a catheter shaft 4851 with an impeller assembly 4861 mounted on a distal portion thereof. The catheter shaft 4851 includes a proximal expandable member 4850 attached to an outer surface of the catheter shaft 4851. The proximal expandable member 4850 includes a flow channel 4854 that allows fluid to bypass the proximal expandable member 4850 at a controllable rate.

Figure 49 is a cross-sectional view taken along line A-A of Figure 48 to reveal the internal lumen of the catheter shaft 4851. An internal lumen extends internally through the catheter shaft 4851. Shown is a proximal expandable member lumen 4901 for delivering fluid, i.e., gas or liquid, used to inflate the proximal expandable member 4850. A separate distal expandable member lumen 4902 is provided for delivering fluid and inflating the distal expandable member 4862. The separate lumens allow the proximal and distal expandable members 4850, 4862 to be operated independently of one another during therapeutic treatment. A pressure sensor lumen 4966 is provided for sensing and receiving electrical signals with one or more pressure sensors disposed on the catheter system 4800. One or more reinforcing lumens 4930 may be provided to reinforce the catheter 4800 so that it may be more easily navigated through the body.

50 is an indwelling catheter 5000. The catheter 5000 includes mechanical components, such as the impeller 5005 and/or drive shaft 5007, and a purge system. The purge system operates to exclude biological fluids and materials from the catheter 5000 and the mechanical components operating within the catheter 5000. In that way, bodily fluids are prevented from entering crevices in the catheter 5000, ensuring smooth and efficient operation of the mechanical parts, such as the impeller 5005 and drive shaft 5007, within the catheter 5000, while also preventing the patient's bodily fluids from progressing to the proximal portion of the catheter 5000 outside the patient's body, where they may leak from the catheter. The purge system will also prevent air from entering the vein through the same channels.

The catheter 5000 may be used to reduce pressure in a region of the venous system. The catheter 5000 includes an impeller assembly 5009 mounted to a distal end of the catheter 5000. The impeller assembly 5009 includes an expandable member 5013, a cage 5015 with an inlet region 5017 and an outlet region 5019, and an impeller therein. The impeller 5005 may rotate at high RPM within the cage 5015. The impeller 5005 may further include a distal surface, a proximal surface, and an impeller blade surface. The distal surface, the proximal surface, and the impeller blade surface are configured to rotate in close proximity to, but without contacting, adjacent surfaces inside the cage.

The impeller assembly 5009 may further include a cuff 5023. The cuff 5023 may include a distal surface 5025 and a proximal surface 5027. The impeller 5005 may rotate within a clearance in the distal surface of the cuff 5023.

The clearance between the cuff distal surface 5025 and the impeller 5005 comprises a proximal gap 5029, which is configured to remain fixed during operation. The proximal gap 5029 is configured to define a transition between the static cuff and the rotating impeller 5005. The proximal gap 5029 is configured to allow blood to flow across the proximal gap 5029 without flow disturbances, flow recirculation, or vortexes. The proximal gap 5029 may be in fluid communication with a catheter lumen, which is in fluid communication with a fluid reservoir external to the patient. The proximal gap 5029 may be configured to prevent blood flow from entering the proximal gap 5029.

In a preferred embodiment, the proximal gap 5029 includes a resistive fluid pressure configured to prevent blood from entering the proximal gap. For example, the resistive fluid can be a purge fluid delivered from a fluid reservoir to the outside of the patient. The purge fluid can be used to purge or wash the proximal gap 5029 and clear debris, for example, as described in commonly owned U.S. Provisional Application No. 62/629,914, which is incorporated herein by reference. The resistive fluid pressure can include a hydrostatic fluid pressure, which can include pulses of fluid pressure. The fluid pressure includes a solution, which can include saline, dextrose, or heparin solution.

The viscosity of the purge solution can be tailored to effectively purge small gaps and orifices. The solution can also be immiscible with blood to prevent blood contact with the purging surfaces. For example, the solution can be a hydrophobic solution. In some embodiments, the proximal gap 5029 can include a seal, such as, for example, a spring-loaded seal.

The clearance between the distal most surface of the impeller 5005 and the tip 5031 comprising the bearing housing 5033 may comprise a distal gap 5041, which may be configured to remain fixed during operation. The distal gap 5041 may be configured to define a transition between the rotating impeller 5005 and the static tip 5031. The distal gap 5041 may be configured to allow blood to flow across the distal gap without flow disturbances, recirculation, or vortexes.

In a preferred embodiment, the distal gap 5041 is in fluid communication with the catheter lumen, which is in fluid communication with a fluid reservoir external to the patient. The distal gap 5041 may be configured to prevent blood flow from entering the distal gap, for example, by providing a purge from a fluid reservoir, as discussed above. The distal gap 5041 may comprise a resistive fluid pressure configured to prevent blood from entering the distal gap. The resistive fluid comprises a hydrostatic pressure. The resistive fluid pressure comprises a pulse of fluid pressure. The fluid pressure comprises a solution, for example, a saline, dextrose, or heparin solution. The viscosity of the purge solution may be tailored to effectively purge small gaps and orifices. The solution may also be immiscible with blood to prevent blood contact with the purge surface. The solution may be a hydrophobic solution. The distal gap 5041 may comprise a seal, for example, a spring-loaded seal.

Figure 51 is an expanded view of dotted circle B of Figure 50, according to an embodiment of the invention. In this embodiment, fluid is delivered from a purge channel 5101 that runs along the central lumen of the device. The purge channel can be external to the PTFE liner that surrounds the central lumen of the catheter.

FIG. 52 is an expanded view of dotted circle B of FIG. 50 according to another embodiment of the present invention. In this embodiment, purge fluid is delivered from a reservoir external to the patient via a purge channel 5201 that travels through the lumen used to inflate the expandable member 5013. The purge channel 5201 is external to the PTFE liner of the drive cable.

Figure 53 is an expanded view of dotted circle B of Figure 50 according to a different embodiment of the present invention. In this embodiment, purge fluid is delivered from purge channel 5301, which extends through a PTFE liner surrounding the drive lumen.

FIG. 54 illustrates distal flushing of the indwelling catheter 5400. A flushing or purging fluid is delivered through the lumen 5403 of the expandable member 5407. The purge proceeds through the lumen 5403 and through the distal bearing housing 5411 to prevent blood spilling into the catheter's bearings. The purge fluid flows into the distal gap 5431, flushing blood and preventing it from filling. The purge fluid proceeds up the second lumen 5437 to the proximal gap 5439, flushing blood from the proximal gap 5439.

55 illustrates distal flushing of an indwelling catheter 5500 according to a different embodiment. In this embodiment, purge fluid is delivered through a purge lumen 5505 that is separate and distinct from the lumen for inflating the expandable member 5507. The purge proceeds through the purge lumen 5505 and into the distal bearing housing 5511, thereby preventing blood spillage into the catheter's bearings. The purge fluid flows into the distal gap 5531, flushing blood and preventing it from filling. The purge fluid then follows a second lumen 5537 to the proximal gap 5539, flushing blood from the proximal gap 5539.

Figure 56 shows an indwelling catheter 5600 with a purge system. The catheter 5600 includes a central lumen 5603 that is optimized to carry purge fluid and maintain concentricity of the catheter 5600 assembly. The internal structure of the central lumen 5306 can have a variety of configurations, some of which are detailed below in a cross-sectional view taken through the cuff 5606 along line A-A.

Figure 57 shows a cross-sectional view of the central lumen 5603 taken along line A-A in Figure 56 according to one embodiment of the present invention. In this embodiment, the purge channel 5709 is external to the drive shaft 5711, which connects the motor to the impeller of the device. Between the purge channel and the drive shaft 5711 is a profile extrusion 5713. The profile extrusion extrusion 5713 includes several protrusions 5715, for example at least two protrusions 5715, preferably three protrusions 5715, which extend outwardly from a central hub 5717 that encases the drive shaft 5711. The profile extrusion 5713 optimizes the purge cross-sectional area and also helps maintain assembly concentricity.

FIG. 58 shows a cross-sectional view of the central lumen 5603 taken along line A-A in FIG. 56 according to a different embodiment of the present invention. In this embodiment, a purge channel 5809 is associated with the drive shaft 5711, which connects the motor to the impeller of the device. The purge channel 5809 is defined by a profile extrusion 5813. The profile extrusion extrusion 5813 includes a number of protrusions 5815, for example at least two protrusions 5815, preferably three protrusions 5815, which extend inwardly from an outer hub 5817 that encases the drive shaft 5711. The profile extrusion 5813 defines and optimizes the purge cross-sectional area and maintains assembly concentricity.

FIG. 59 shows a cross-sectional view of the central lumen 5603 taken along line A-A of FIG. 56 according to another embodiment of the present invention. In this embodiment, the central lumen 5603 houses a coil drive shaft 5905, which connects the motor to the impeller of the device. A purge channel 5909 surrounds the coil drive shaft 5905. The purge channel 5909 is defined by an outer hub 5911 that encases the coil drive shaft 5905.

FIG. 60 shows an optimized guide surface 6001 of the cage inlet 6003. Referring to FIG. 27, the optimized guide surface 6001 comprises a portion of the cuff 6007 that tapers toward the impeller 6011 in harmony with the outer boundary surface 6015. The optimized guide surface 6001 maintains axial momentum and prevents recirculation of the fluid 6017 entering the cage assembly 6021. In particular, the optimized guide surface 6001 tapers in a manner that creates flow field focusing and minimizes fluid focusing in the inlet region 6003. The optimized guide surface 6001 may comprise a curved tapered section. The optimized guide surface 6001 may be configured to smoothly reduce the cross-sectional area along the length of the inlet 6003. For example, the change in cross-sectional area of the optimized guide surface 6001 along the length of the inlet 6003 may be less than or equal to about 1 ^mm2 . The optimized guide surface 6001 may comprise a curved taper. The optimized guide surface 6001 may comprise a cylindrical section. The optimized guide surface 6001 may comprise a generally conical section.

In some embodiments, the outer boundary surface 6015 tapers over at least a portion of the inlet region 6003. With reference to FIG. 17, the outer boundary surface 6015 may comprise a proximal surface of the expandable member. Alternatively, the outer boundary surface 6015 may comprise an inner surface of the cage.

FIG. 61 illustrates a sub-optimal guide surface 6105. The sub-optimal guide surface 6105 can cause disturbances in the flow 6107 of the fluid entering the inlet region 6111. In particular, the sub-optimal guide surface 6105 has a steeper profile compared to the optimized guide surface 6017 of FIG. 60. The steeper profile causes changes in the axial momentum and fluid convergence of the blood entering the inlet region 6111. These disturbances in the flow 6107 are prevented by the optimized guide surface 6017.

Figure 62 shows the cage inlet 6201. Shown is the optimal configuration where the fluid flow 6207 is aligned with the inlet 6201 along the optimized guide surface 6017. The flow 6207 is primarily in the X direction with no rotational component which promotes a smooth flowing inlet 6201.

Figure 63 shows a suboptimal inlet 6301 configuration. This suboptimal configuration includes a steep guide surface 6105 that causes recirculation and stalls the flow in the inlet. A rotational component of the velocity dominates and conveys the flow below the inlet struts 6215. This phenomenon creates a disturbed flow 6217 in the inlet 6301, reducing the effectiveness of the inlet 6301 in directing the flow towards the impeller.

(Incorporated by reference)
References and citations to other documents, such as patents, patent applications, patent publications, journals, books, articles, web content, etc. are made throughout this disclosure. All such documents are incorporated herein by reference in their entirety for all purposes.

(Equivalents)
Various modifications of the present invention and many further embodiments thereof, in addition to those shown and described herein, will be apparent to those skilled in the art from the entire contents of this document, including the scientific and patent references cited herein. The subject matter of this specification contains important information, exemplification, and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents.

Claims (17)

A device, the device comprising:
a catheter having a proximal portion and a distal portion;
an impeller housing attached to the distal portion of the catheter, the impeller housing having an impeller disposed therein;
an expandable member aligned on an exterior of the impeller housing, an exterior surface of the expandable member directly physically coupled to the exterior surface of the impeller housing , the expandable member positioned at least partially proximal to the impeller such that when the expandable member expands and is in an expanded state, a portion of an inner diameter of the expandable member extends across a portion of an inlet of the impeller housing and directs fluid flow into the inlet of the impeller housing. The device of claim 1, wherein the expandable member surrounds and is attached to the proximal end of the impeller housing. The device of claim 1, wherein the expandable member is a balloon, the balloon defines an annular shape when expanded, and a proximal surface of the annular shape directs fluid into the impeller housing. The device of claim 3, wherein the balloon is inflatable, the balloon surrounds and is attached to the proximal end of the impeller housing, and the annular shape directs fluid into the inlet of the impeller housing. The device of claim 1, wherein the impeller housing comprises a metal and a portion of the expandable member is physically bonded to a surface of the metal by an adhesive. The device of claim 5, wherein at least a portion of the surface of the metal is impregnated with a polymer to promote bonding to the adhesive. The device comprises:
a motor housing connected to the proximal portion of the catheter;
a motor disposed within the motor housing;
a drive cable extending through the catheter from the motor to the impeller;
The device of claim 1 , further comprising: an inflation lumen extending along the catheter to the expandable member. A device, the device comprising:
a catheter having a proximal portion and a distal portion, the distal portion sized for insertion into a lumen of a patient, the distal portion comprising a housing, the housing comprising a pump disposed within the housing;
an expandable member connected to the pump, the expandable member disposed about the proximal portion of the housing when unexpanded, the expandable member having an annular shape when expanded, a proximal surface of the annular shape and an inner surface of the housing forming a smooth continuous surface for channeling fluid through the housing under the force of the pump. The device of claim 8, wherein the housing comprises a metal, a portion of the expandable member is secured to a surface of the metal by an adhesive, and at least a portion of the surface of the metal is impregnated with a polymer to promote bonding to the adhesive. The device of claim 8, wherein the expandable member comprises an inflatable balloon mounted on the proximal end of the pump housing. The device of claim 10, wherein the pump comprises an impeller disposed within the housing, and the inflatable balloon is mounted about the proximal end of the housing. The device of claim 11, wherein the housing comprises a distal portion and a proximal portion, the outer diameter of the proximal portion being smaller than the outer diameter of the distal portion. The device of claim 12, wherein the impeller comprises one or more blades on a shaft, and a radial measurement taken from the axis of the impeller to the outer edge of the blade decreases from the distal portion to the proximal portion of the impeller. The device of claim 13, wherein an outer edge of each blade includes a dog leg defining a decreasing radius disposed adjacent a transition between the distal and proximal portions of the housing. The device of claim 13, wherein the distal portion of the housing includes one or more outlets, the shaft flares outwardly near a distal end of the impeller, and when the impeller is rotated, the impeller pumps blood through the housing and out the one or more outlets. The device of claim 8, wherein the pump comprises an impeller disposed within the housing, and the expandable member comprises an inflatable balloon connected to an exterior surface at a proximal end of the housing. The device of claim 16, wherein the inflatable balloon defines an annulus when inflated.

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