JP6681453B2 - Abrasive elements for a rotary atherectomy system - Google Patents

Description

  [0001] The present disclosure is generally directed to systems, devices and methods for atherectomy. More specifically, the present disclosure is directed to novel shapes of abrasive elements used in atherectomy procedures.

  [0002] Atherosclerosis is the major cause of coronary heart disease. Atherosclerosis occurs when lipids, cholesterol and / or other substances accumulate in the walls of blood vessels to form hard structures called plaques and / or atherosclerotic lesions. Over time, these plaques and / or lesions may increase in size such that blood vessels become blocked and / or completely occluded.

  [0003] Rotary atherectomy is a technique used, for example, to polish calcified arterial lesions. Also, the rotary atherectomy device and the rotary atherectomy procedure may be referred to as a rotary angioplasty device and / or a rotary angioplasty procedure. One type of rotary atherectomy device is known as an orbital atherectomy device.

  [0004] The rotary atherectomy device can include an abrasive element attached to the proximal portion of the rotatable flexible drive shaft. A rotatable flexible drive shaft may be carried to the desired location on the guidewire and / or through the sheath. Abrasive elements may be referred to as burrs, crowns and / or beads. The drive shaft may be rotated at high speed (eg, between 20,000 and 160,000 rpm). As the polishing element rotates, it can be advanced over the stenotic lesion or plaque to contact the occluded tissue and / or plaque. In this way, the abrasive element rubs the lesion surface, abrading the lesion into very small particles. These small particles can be removed from this site by the bloodstream.

  [0005] The devices, systems and methods of the present disclosure have several features, no single one of which is solely responsible for its desirable properties. Without limiting the scope of the invention described below, which is represented by the claims, its superior features are briefly discussed. After considering this discussion, and especially after reading the "Modes for Carrying Out the Invention" section, how the features of the present disclosure provide several advantages over other rotary atherectomy systems. Will be understood.

  [0006] The present disclosure is directed to novel bead shapes that can provide improved polishing efficiency in atherectomy procedures. One embodiment is a fast rotating atherectomy device for opening stenoses in an artery having a lumen extending therethrough. The device can include a flexible elongated rotatable drive shaft. The device can also include a guidewire having a maximum diameter that is less than the diameter of the lumen. In such an embodiment, the drive shaft may be advanceable over the guide wire. Abrasive elements may be arranged on the drive shaft. The polishing element can have a first center of mass offset in a first radial direction from a center of mass of the drive shaft. The polishing element can have a second center of mass offset from the center of mass of the drive shaft in a second radial direction. The second center of mass may be positioned proximal to the first center of mass. The second radial direction may be mainly opposite to the first radial direction. In some aspects, the polishing element is eccentric in shape.

  [0007] The polishing element can have a proximal end and a distal end. The polishing element can have a total center of mass located between the proximal and distal ends. In some embodiments, the total center of mass can be located at the midpoint between the proximal and distal ends. The distal end can have a center of mass offset in the first radial direction from the center of mass of the drive shaft. The proximal end may have a center of mass offset in the second radial direction from the center of mass of the drive shaft. The second radial direction may be opposite to the first radial direction. In some aspects, the polishing element comprises a waist disposed between the proximal end and the distal end of the polishing element. In some aspects, at least a portion of the outward facing surface is roughened, i.e. rough compared to the outer surface of the drive shaft. In some aspects, the center of mass comprises a heavier material than the rest of the polishing element. In other words, the center of mass of the polishing element can include a material having a higher density than that of the material of the rest of the polishing element. In some aspects, the polishing element is positioned on the drive shaft to allow the polishing element to move radially with respect to the drive shaft. For one embodiment, it is not unthinkable that the polishing element comprises a distal portion, a central portion and a proximal portion. In such an embodiment, each of these portions may have a radially offset center of mass, the radial direction being more or less the same with respect to the distal and proximal portions. Good. For the central portion, this offset may be in a direction that is substantially opposite the offset direction for the distal and proximal portions. The center of mass of the distal and proximal portions obtained in combination can be proximal or distal from the center of mass of the central portion as viewed in the longitudinal direction of the drive shaft. However, it is not unthinkable that the combined center of mass of the distal and proximal parts, with respect to their longitudinal position along the drive axis, coincides with the center of mass of the central part. The center of mass may be balanced or slightly unbalanced with respect to the drive axis.

  [0008] Another embodiment is a fast rotating atherectomy device for opening a stenosis in an artery having a lumen extending therethrough. The device can comprise a flexible elongate rotatable drive shaft sized and shaped for insertion into the lumen. The device can also include a body. The body can have a radially expandable structure at a location between its distal and proximal ends. At least two polishing elements may be arranged on the outer surface of the body and may be distributed around the radially expandable structure, so that when rotating the drive shaft at least two polishing elements. The elements are pulled away from each other, radially increasing the size of the radially expandable structure between them. The body can have a slot extending through a side of the body at a location between its distal and proximal ends. The proximal and distal ends can be coupled to a flexible elongate rotatable drive shaft. The body and drive shaft can be advanceable over a guide wire. The body can include an elongated tube. Abrasive elements may be located on either side of the slot. When the drive shaft is rotated, the at least two polishing elements can be pulled away from each other, increasing the width of the slot between them. In some aspects, the polishing element and the body are formed of different materials, ie, the polishing element may be formed of a different material than the material from which the body is formed. In some aspects, at least two polishing elements are located at different longitudinal locations along the body. In some embodiments, a rod extends from the proximal end of the slot to the distal end of the slot. The polishing element can have a rough outer surface as compared to the outer surface of the drive shaft. It is not unthinkable that an embodiment comprises three polishing elements or more. These may be evenly distributed around the radially expandable structure. The centers of mass may be balanced with respect to the drive axis or may be slightly unbalanced from each other.

[0009] Another embodiment includes a method of excising a lesion in a blood vessel. The method can include advancing a guidewire through the blood vessel. The sheath can be advanced over the guidewire. The sheath can have a proximal end, a distal end, and a lumen extending therethrough. The sheath can include an introducer sheath. In aspects, the sheath comprises a catheter having a lumen extending therethrough. The method can also include advancing a flexible drive shaft over the guidewire and within the sheath. The drive shaft can have a proximal end, a distal end, and an abrasive element attached to the distal end. The polishing element can have a first diameter. The method can also include advancing the polishing element out of the distal end of the sheath and rotating the drive shaft to increase the first diameter of the polishing element. The method can also include the step of excising the lesion. In some aspects, the polishing element is constrained to a second diameter that is less than the first diameter as the polishing element is advanced through the sheath. This diameter may be the effective diameter.

  [0010] These and other features, aspects, and advantages of the invention disclosed herein are intended to exemplify the invention and are not intended to limit the same to the figures of specific embodiments. Described below with reference. Additionally, throughout the drawings, the same reference numbers are used to indicate the same components in the illustrated embodiments. The following is a brief description of each of the figures.

[0011] FIG. 1 is a schematic perspective view of an atherectomy system that may be used with the polishing elements disclosed herein, the atherectomy system comprising a drive system coupled to a drive shaft. Yes, the polishing element can be coupled to the distal portion of the drive shaft. [0012] FIG. 1A is an enlarged perspective view of a polishing element coupled to a distal portion of the drive shaft shown in FIG. [0013] FIG. 1B is an enlarged perspective view of the polishing element of FIGS. 1 and 1A with the drive shaft removed. [0014] FIG. 3 is a side view of the polishing element of FIG. [0015] FIG. 3 is a top view of the polishing element of FIG. [0016] FIG. 5 is a cross-sectional view of the polishing element of FIG. 4 taken along line 5-5. [0017] FIG. 4 is a front view of the polishing element of FIG. [0018] FIG. 4 is a rear view of the polishing element of FIG. [0019] FIG. 3 is a schematic cross-sectional view of the polishing element of FIG. 2 coupled to a drive shaft and biased against the inner wall of the sheath. [0020] FIG. 8B is a cross-sectional view taken around line 8B-8B of FIG. 8A. [0021] FIG. 8B is the same view as FIG. 8A, except that the polishing element has been removed from the sheath and returned to the unbiased position. [0022] FIG. 8D is a cross-sectional view taken about line 8D-8D in FIG. 8C. [0023] FIG. 8B is the same view as FIG. 8A, except that the polishing element is coupled to the drive shaft in an alternative manner, and the polishing element is biased against the inner wall of the sheath. There is. [0024] FIG. 8F is a cross-sectional view taken around line 8F-8F of FIG. 8E. [0025] FIG. 8E is the same view as FIG. 8E, except that the polishing element has been removed from the sheath and returned to the unbiased position. [0026] FIG. 8D is a cross-sectional view taken around line 8H-8H of FIG. 8G. [0027] FIG. 8G is the same view as the polishing element is rotated at high speed, and as shown, at least a portion of the polishing element is movable with respect to the drive shaft. [0028] FIG. 8D is a cross-sectional view taken about line 8J-8J of FIG. 8I. [0029] FIG. 9 is a schematic cross-sectional view of a blood vessel showing exemplary operation of the polishing element disclosed herein. [0030] FIG. 3 is a schematic side view of a polishing element according to another embodiment, which is similar to the polishing element of FIG. 2, but without the oblique inner lumen extending therethrough. [0031] FIG. 10B is the same view as FIG. 10A, except that the polishing element is shown as biased against the inner wall of the sheath. [0032] FIG. 6 is a perspective view of a polishing element according to another embodiment, as shown, the polishing element includes a slotted tube and two polishing protrusions disposed on the outer surface of the tube and on either side of the slot. , Is provided. [0033] FIG. 12 is an exploded view of the polishing element of FIG. [0034] FIG. 13 is a perspective view of the slotted tube of FIG. [0035] FIG. 13 is a side view of the slotted tube of FIG. [0036] FIG. 13 is a top view of the slotted tube of FIG. [0037] FIG. 15 is a front view of the slotted tube of FIG. [0038] FIG. 13 is a perspective view of one of the polishing protrusions of FIG. [0039] FIG. 18 is a top view of the polishing protrusion of FIG. [0040] FIG. 18 is a bottom view of the polishing protrusion of FIG. [0041] FIG. 18 is a side view of the polishing protrusion of FIG. [0042] FIG. 18 is a front view of the polishing protrusion of FIG. [0043] FIG. 12 is a side view of the polishing element of FIG. [0044] FIG. 12 is a top view of the polishing element of FIG. [0045] FIG. 12 is a cross-sectional view of the polishing element of FIG. [0046] Same as FIG. 22, but showing the polishing element in an unsuppressed state. [0047] FIG. 12 is a side view of the polishing element of FIG. 11 positioned in a sheath and in a restrained state. [0048] FIG. 12 is a side view of the polishing element of FIG. 11 when the polishing element is rotated at high speed, and as shown, the polishing protrusions open slots when the polishing element is rotated at high speed. [0049] FIG. 27 is a cross-sectional view of FIG. 26 taken around line 28-28. [0050] FIG. 26 is a cross-sectional view of FIG. 25 taken around line 29-29. [0051] FIG. 28 is a cross-sectional view of FIG. 27 taken around line 30-30. [0052] FIG. 12 is a perspective view of a polishing element according to another embodiment, which is similar to the embodiment of FIG. 11, except that two polishing protrusions at least partially overlap the slots. [0053] FIG. 32 is a side view of the polishing element of FIG. [0054] FIG. 32 is a top view of the polishing element of FIG. [0055] FIG. 33 is a cross-sectional view of the polishing element of FIG. 32 taken around line 34-34. [0056] FIG. 32 is a side view of the polishing element of FIG. 31 positioned within a sheath. [0057] FIG. 35B is a cross-sectional view of FIG. 35A taken around line 35B-35B. [0058] FIG. 32 is a side view of the polishing element of FIG. 31 when the polishing element is rotated at high speed. 36B is a cross-sectional view of FIG. 36A taken around line 36B-36B. [0059] FIG. 12 is a perspective view of a polishing element according to another embodiment, which is similar to the embodiment of FIG. 11, except that the rod is positioned on a slot within a slotted tube, , May be referred to as a dual slotted embodiment. Although not shown, a dual slotted version of the device of Figure 31 is also contemplated. [0060] FIG. 38 is an exploded view of the polishing element of FIG. [0061] FIG. 39 is a perspective view of the double slotted tube of FIG. 38. [0062] FIG. 39 is a side view of the double slotted tube of FIG. 38. [0063] FIG. 39 is a top view of the double slotted tube of FIG. 38. [0064] FIG. 41 is a front view of the dual slotted tube of FIG. [0065] FIG. 38 is a side view of the polishing element of FIG. 37, showing the polishing element in an unrestrained state. [0066] FIG. 38 is a side view of the polishing element of FIG. 37 positioned within the sheath in a constrained state. [0067] FIG. 38 is a side view of the polishing element of FIG. 37 when the polishing element is rotated at high speed. [0068] FIG. 45 is a cross-sectional view of FIG. 44 taken around line 46-46. [0069] FIG. 44 is a cross-sectional view of FIG. 43 taken around line 47-47. [0070] FIG. 48 is a cross-sectional view of FIG. 45 taken around line 48-48. [0071] FIG. 50 is a perspective view of a polishing element according to another embodiment, wherein the embodiment of FIG. 49 is similar to the embodiment of FIG. 11, but with a different shaped polishing protrusion. [0072] FIG. 50 is a side view of the polishing element of FIG. 49. [0073] FIG. 51 is a top view of the polishing element of FIG. [0074] FIG. 51 is a cross-sectional view of the polishing element of FIG. 50 taken around line 52-52. [0075] FIG. 54 is a perspective view of a polishing element according to a different embodiment, the embodiment of FIG. 53 being similar to the embodiment of FIG. 49 except that the polishing protrusions are offset from each other along the longitudinal axis. . [0076] FIG. 54 is a side view of the polishing element of FIG. 53. [0077] FIG. 55 is a top view of the polishing element of FIG. 54. [0078] FIG. 55 is an axial view of the polishing element of FIG. 54.

  [0079] The following description and examples illustrate preferred embodiments of the inventive rotary atherectomy device disclosed in the context of use in an atherectomy procedure. More particularly, these embodiments relate to, for example, rotary atherectomy devices and related techniques used to ablate calcified lesions within blood vessels.

  [0080] The following description and accompanying drawings, which describe and illustrate preferred embodiments, are prepared to demonstrate a number of possible configurations. These configurations allow for atherectomy devices and / or systems to incorporate various aspects and features disclosed. Those skilled in the art are not limited to any particular atherectomy system or device in which the disclosed aspects and features may include one or more of the inventive aspects and features disclosed herein. You will understand that. Further, the disclosed embodiments can be used with a variety of commercial devices in a variety of medical procedures.

  [0081] Particular implementations of the subject matter described in this specification can be implemented to realize one or more of the following potential advantages. The atherectomy devices described herein are specifically configured to more efficiently ablate calcified lesions within blood vessels. In some embodiments, the device comprises a polishing element, the polishing element configured to move at least a portion thereof away from a central axis of the drive shaft. In some embodiments, the device comprises a distal polishing element, the distal polishing element configured to expand when rotated at high speed. In this way, the abrasive elements disclosed herein can be expanded further out of the drive shaft to press against the lesion. In other words, the polishing elements disclosed herein have larger polishing and / or scraping areas than other polishing elements.

[0082] In some embodiments, the polishing element can effectively allow a larger polishing element to fit within a standard lumen when delivered to a location of interest. . For example, the abrasive element can be configured to be radially constrained when placed within the lumen and then expand radially when it exits the lumen. The polishing element may be further configured to further expand radially when rotated. In this way, the abrasive element disclosed herein can open a stenotic lesion to a diameter substantially greater than the maximum diameter of the abrasive element and / or the sheath through which the abrasive element is carried. . Thus, the polishing elements disclosed herein can have improved polishing coverage, increased scraping area, can reduce treatment time, and / or make restenosis more effective. Can be prevented.

  [0083] Various aspects are now described with reference to particular forms or embodiments selected for purposes of illustration. It will be appreciated that the spirit and scope of the atherectomy system disclosed herein is not limited to any selected form. Further, it should be noted that the figures provided herein are not drawn to any particular proportion or scale and many modifications may be made to the illustrated embodiments. A brief introduction to some of the features common to the described embodiments of the atherectomy system will now be described.

  [0084] To assist in the description of these components of the atherectomy system, the following coordinate terms are used. The "longitudinal axis" is generally parallel to the elongated sides of the polishing elements disclosed herein. For example, see FIG. The "radial axis" is perpendicular to the longitudinal axis and extends radially.

  [0085] Additionally, as used herein, "longitudinal" refers to a direction substantially parallel to the longitudinal axis, and "radial" is substantially to the radial axis. Refers to the direction parallel to. The term "axial" may be used herein and is a synonym for the term "longitudinal" as used herein.

  [0086] Also, the terms "proximal" and "distal" used to describe the atherectomy system of the present invention are used consistently with the description of the exemplary application (the particular illustrated example). To be done. Thus, proximal and distal are used with reference to the handles of the atherectomy system.

  [0087] The terms "upper", "lower", "top", "bottom", "lower surface", "upper surface", etc. used to describe the atherectomy system of the present invention are illustrated. Used with reference to the orientation of the embodiments. For example, the term "upper surface" may be used to describe the portion of the polishing element that lies above the longitudinal and / or radial axis through the center of the polishing element. The term "lower surface" may be used to describe the portion of the polishing element that lies below the longitudinal and / or radial axis through the center of the polishing element.

[0088] FIG. 1 illustrates a rotary atherectomy system 1 according to one embodiment. The system 1 comprises a drive system 3 configured to rotate a flexible drive shaft 5 at high speed (eg 20,000 to 160,000 rpm). The drive system 3 can comprise an electric motor. Drive system 3 is a Boston Scientific Rotablator, Cardiovascular
Systems Inc. (“CSI”) Stealth, CSI Diamondback360, and / or can include or be designed to have portions substantially similar to other similar devices. The drive shaft 5 can be advanceable over a guide wire (not shown) or through a sheath. The drive shaft 5 can include a proximal end coupled to the drive system 3 and a distal end for insertion into a patient. The drive shaft 5 can extend, for example, through the lumen of an artery. In some embodiments, the rotary atherectomy system 1 comprises a sheath. In some embodiments, a catheter having a lumen extending therethrough is coupled to the proximal end of the drive shaft. In such an embodiment, the drive shaft 5 may extend through the lumen of the catheter.

  [0089] A polishing element 200 may be coupled to the distal portion of the drive shaft 5, as shown in FIG. 1A. In some embodiments, the polishing element 200 is coupled to the drive shaft 5 at a location proximal to the distal end. For example, the polishing element 200 may be coupled to the drive shaft 5 at a location that is approximately 20 mm proximal to the distal end of the drive shaft 5. In some embodiments, the polishing element 200 is located approximately 10 mm proximal to the distal end of the drive shaft 5. The drive shaft 5 can include a winding wire. In another embodiment, the drive shaft 5 comprises a tube.

  [0090] The polishing element 200 can include a proximal end 213 and a distal end 211. The polishing element may be between about 1 and 25 mm long. In another embodiment, the polishing element is about 1 to 15 mm long. In some embodiments, the polishing element is about 6 mm long. The polishing elements disclosed herein can be made of any suitable material or combination thereof. For example, the polishing element or a portion thereof may be made of surgical stainless steel, titanium, tungsten, nitinol, or the like. In some embodiments, the polishing element is solid as opposed to hollow. In some embodiments, the polishing element comprises a raised waist located between the proximal and distal ends. In some embodiments, the polishing element has an eccentric shape.

  [0091] Turning to FIG. 2, an enlarged view of the polishing element 200 according to the embodiment of FIGS. 1 and 1A is shown. As shown, the polishing element 200 comprises a generally cylindrical bead 201 having a beveled end 205 and a lumen 203 extending therethrough. The polishing element 200 may be mounted on a flexible drive shaft 5 which is rotated at high speed by an electric motor. Generally, the polishing element 200 is coupled to the drive shaft 5 such that the polishing element 200 and the drive shaft 5 rotate integrally about a longitudinal axis passing through the center of the drive shaft 5. That is, the polishing element 200 may be coupled to the drive shaft 5, whereby the polishing element 200 is restrained from moving with respect to the drive shaft 5. In another embodiment, the polishing element 200 is configured to be restrained from moving longitudinally with respect to the drive shaft 5, but not transversely and / or laterally. In some embodiments, the polishing element 200 moves in cooperation with at least a portion of the drive shaft 5 located within the polishing element 200.

  [0092] In some embodiments, at least a portion of the drive shaft 5 positioned within the polishing element 200 is welded to at least a portion of the interior surface of the lumen 203. In certain embodiments, the polishing element 200 is welded to the entire interior surface of the lumen 203. In other embodiments, the polishing element 200 is crimped such that at least a portion of the lumen 203 engages at least a portion of the drive shaft 5 positioned within the lumen 203. In some embodiments, the proximal portion of the lumen is welded to the proximal portion of the drive shaft and the distal portion of the lumen is welded to the distal portion of the drive shaft. For example, in some embodiments, a laser is used to melt at least a portion of polishing element 200 against at least a portion of drive shaft 5.

  [0093] The polishing element 200 can include a roughened outer surface 207. The roughened outer surface 207 can improve the polishing ability of the polishing element 200. In some embodiments, the roughened exterior surface 207 comprises diamond particles deposited on one or more of the exterior surfaces of the polishing element 200. The diameter of these particles may be about 20 μm. Although the polishing element 200 is shown as having a roughened overall outer surface, in some embodiments the outer surface is roughened to a lesser extent than the overall outer surface. The roughened outer surface 207 can be similar to sandpaper and can enhance the ability of the polishing element 200 to ablate a lesion.

[0094] An example shape of the polishing element 200 is further shown in FIGS. As best shown in FIG. 5, a lumen 203 extending through the polishing element 200 extends obliquely within the generally cylindrical bead 201. In other words, the lumen 203 extends from the left bottom corner of the distal end 211 of the cylindrical bead 201 to the upper right corner of the proximal end 213 of the cylindrical bead 201, as shown in FIG. In this way, when the polishing element 200 is mounted on the flexible drive shaft 5 positioned within the lumen 203, as shown for example in FIG. It extends radially further away from the flexible drive shaft 5 than other outer surfaces of the element 200. In this way, the ends of the distal 211 and the proximal 213 can have a local center of mass, which is oblique to each other, from the center of the longitudinal axis of the drive shaft 5. Exist at a distance. For example, as shown in FIG. 1A, the local center of mass of the distal end 211 of the polishing element 200 is located on the upper surface of the drive shaft 5 and the local center of mass of the proximal end 213 of the polishing element 200. Are located on the lower surface of the drive shaft 5.

  [0095] In some embodiments, the beveled end 205 is shaped to improve tracking of the polishing element 200 through the vasculature. For example, one or more angled surfaces can improve the ability to insert the polishing element 200 through a tortuous path and / or a narrow passage. The beveled end 205 can also help facilitate the polishing element 200 through calcified material within blood vessels.

  [0096] Although a generally cylindrical bead 201 is shown, other shapes are possible. For example, in some embodiments, the polishing element 200 can include a waist that is larger or smaller in diameter than the rest of the generally cylindrical bead 201.

  [0097] As shown in FIG. 5, the angle of the lumen 203 can create two offset local centers of mass located near the distal and proximal ends of the polishing element 200. . That is, due to the oblique lumen 203, there is more mass below the longitudinal axis extending through the center of the polishing element 200 at the proximal end 213 than at the distal end 211. Similarly, the oblique lumen 203 causes more mass to exist at the distal end 211 than at the proximal end 213 above the longitudinal axis extending through the center of the polishing element 200.

  [0098] In other embodiments, the distal and / or proximal ends may be made of a heavier material than the material of the rest of the polishing element 200. For example, in some embodiments, the beveled end 205 and / or at least a portion of the volume disposed below the beveled end 205 is made of a heavier material than the material of the rest of the polishing element 200. For example, in some embodiments, at least a portion of the distal end 211 and the proximal end 213 of the generally cylindrical bead 201 is made from tungsten, while the remainder of the generally cylindrical bead 201. The part of is made of steel. In this way, the heavier material at the distal end 211 and the proximal end 213 can further disperse the two masses, which are eccentrically located on both ends and on both sides of the polishing element 200. To do. In some embodiments, at least a portion of polishing element 200 is hollow. For example, in some embodiments at least a portion of the distal end and at least a portion of the proximal end comprise at least one hollow portion.

  [0099] In operation, the distribution of mass within the polishing element 200 can change the polishing angle of the polishing element 200 with respect to the longitudinal axis extending through the lumen of the blood vessel. For example, at low speeds, the sides of the generally cylindrical bead 201 can contact and ablate material deposited on the walls of the vessel lumen. At high speeds, the offset local centers of mass may cause the polishing element 200 to wobble with respect to the longitudinal axis extending through the vessel. In this way, the beveled end 205 of the polishing element 200 can also contact and ablate material deposited on the wall of the vessel lumen. In some embodiments, this variable polishing angle of polishing element 200 can enhance the effectiveness of the atherectomy device.

[0100] In some embodiments, mass distribution within the polishing element 200 can increase the static friction that the polishing element 200 has with the material deposited on the walls of the vessel lumen. For example, the mass distribution within the polishing element 200 can reduce the degree to which the polishing element springs away from the material with which it contacts when rotated. Therefore, in some embodiments, the distribution of mass of the polishing element 200 can enhance the effectiveness of the atherectomy device. The relative size and shape of the polishing element 200 can also be modified to increase stiction. For example, in some embodiments, the polishing element 200 comprises one or more protrusions and / or irregularities to increase the static friction of the polishing element with the material being ablated.

  [0101] As best shown in FIGS. 2, 4 and 5, the polishing element 200 includes a proximal notch 223 in communication with the proximal end of the lumen 203 and a distal end of the lumen 203. A distal notch 221 that communicates with the. Thus, lumen 203 opens upwardly and distally, and downwardly and proximally. Proximal notch 223 and distal notch 221 can provide a weld area. That is, the weld can be at least partially disposed within the proximal notch 223 and / or the distal notch 221 to secure the polishing element 200 to the drive shaft 5. In some embodiments, the proximal notch 223 and the distal notch 221 maximize the distance between the two offset local center of mass while maintaining a low profile while carrying the polishing element 200. Can help you. In some embodiments, the cutout can remove mass from portions of the proximal and distal ends to create two offset local centers of mass.

  [0102] In certain embodiments, the polishing element 200 can be axially moved at an angle to the longitudinal axis of the drive shaft 5. In other words, at least a portion of the drive shaft 5 can pass through at least a portion of the distal notch 221 and / or the proximal notch 223. Accordingly, the polishing element 200 is coupled to the drive shaft 5 such that movement in the longitudinal direction with respect to the drive shaft 5 is suppressed, but the polishing element 200 is moved in the longitudinal direction intersecting and / or lateral to the drive shaft 5. Doing is not suppressed. Thus, when the drive shaft 5 and the polishing element 200 are rotated about the longitudinal axis, the proximal end and / or the distal end of the polishing element 200 may be further away from the central axis of the drive shaft 5. . In other embodiments, the polishing element 200 is mounted on the drive shaft 5 such that movement relative to the drive shaft 5 is constrained. In certain embodiments, the polishing element 200 can be coupled to the drive shaft 5 such that the distal end of the polishing element 200 can move radially with respect to the drive shaft.

  [0103] Figures 8A-8D show example positions of the polishing element 200 attached to the flexible drive shaft 5. As shown in FIGS. 8A-8D, the weld 800 can secure the polishing element 200 to the drive shaft 5. Welds may be placed at or near the proximal and distal ends of polishing element 200. As shown in FIGS. 8B and 8D, the weld 800 may be disposed around the lumen 203 and the circumference of the drive shaft 5.

[0104] In Figures 8A-8B, the polishing element 200 attached to the flexible drive shaft 5 is shown in a restrained position within the sheath 801. The polishing element 200 can be moved to an unrestrained position when advanced and out of the sheath, as shown in FIGS. 8C-8D. That is, the effective diameter of the polishing element 200 increases as the polishing element 200 exits the sheath 801 (eg, length d ₂ in FIG. 8D is greater than d ₁ in FIG. 8B). In some embodiments, the polishing element 200 has an uninhibited or deployed profile that is 10-60% greater than the constrained profile, or 35-45% greater, or at least 40% greater. The portions of the polishing element 200 that overlap a portion of the drive shaft 5 may be fixed together so that the polishing element 200 and a portion of the drive shaft 5 within the polishing element 200 move in concert.

[0105] FIGS. 8E-8J illustrate example positions of a polishing element 200 attached to a flexible drive shaft 5 according to another embodiment. 8E-8J show the abrasive element 200 attached to the flexible drive shaft 5 by a weld 800. Although the attachment means is described as a weld, other attachment means may be used. For example, in some embodiments, an adhesive is used to attach the polishing element 200 to the flexible drive shaft 5. As shown, the weld 800 is located approximately in the center of the polishing element 200 and joins the outer surface of the drive shaft 5 to the inner surface of the lumen 203. However, the weld 800 can cover more or less than the area shown. For example, in some embodiments, weld 800 couples the entire length of lumen 203 to drive shaft 5. In other embodiments, the weld 800 does not contact all of the diameter 203 surface of the lumen 203. As discussed above, the weld 800 prevents the polishing element 200 from moving longitudinally with respect to the drive shaft 5. Depending on the type, size and / or location of weld 800, polishing element 200 may or may not move radially relative to drive shaft 5 during rotation.

  [0106] In certain embodiments, the weld 800 allows the polishing element 200 to pivot about the weld 800. That is, a portion of the polishing element 200 can move and / or rotate radially. In other embodiments, welds 800 are located at the proximal and distal ends of the polishing element as described above. In some embodiments, the portion of the polishing element 200 that overlaps the portion of the drive shaft 5 is secured together such that the polishing element 200 and the portion of the drive shaft 5 within the polishing element 200 cooperate. Moving.

[0107] In FIGS. 8E-8F, the polishing element 200 attached to the flexible drive shaft 5 is shown in a restrained position within the sheath 801. The polishing element 200 can move to the unrestrained position when advanced out of the sheath as shown in FIGS. 8G-8H. That is, the effective diameter of the polishing element 200 increases as the polishing element 200 exits the sheath 801 (eg, d ₃ in FIG. 8J is longer than d ₂ in FIG. 8H). In some embodiments, the polishing element 200 has an uninhibited or deployed profile that is 10-60% greater than the constrained profile, or 35-45% greater, or at least 40% greater. In certain embodiments, when the polishing element 200 and flexible drive shaft 5 are rotated as shown in FIGS. Further away from the central axis of 5. Therefore, the polishing range of the polishing element 200 can be further increased, and the polishing element 200 can have an even larger effective diameter when rotated (eg, d ₃ in FIG. 8J, FIG. 8H). Is larger than d _{2 of} ). Thus, within a tightly closed vessel, centrifugal forces acting on the local centers of mass of the distal and proximal ends of the polishing element 200 allow the polishing element 200 to have a larger effective diameter, and The effectiveness of the device is improved and / or the treatment time is reduced.

[0108] FIG. 9 schematically illustrates exemplary operation of the polishing elements disclosed herein. When the blood vessel 900 is opened by the rotating polishing element 200, 300, 1000, the shape of the polishing element (s) may also cause and / or facilitate a second movement. The small track 920 represents the path that the outermost radially facing surface of the polishing element can follow as the drive shaft 5 and the polishing element are rotated. The small track 920 may represent the path of the polishing element 200 as it wobbles with respect to the longitudinal axis passing through this center. In other words, the effective diameter of the small track 920 may be increased by relative movement of the polishing element with respect to the longitudinal axis through the center of the polishing element and / or by physical deformation of the polishing element. In some embodiments, the small track 920 can increase in effective diameter as the polishing element is rotated. In certain embodiments, for example, the effective diameter of the polishing element can have a first diameter at a first rotational speed and a second effective diameter at a second rotational speed. The second effective diameter can be larger in size than the first effective diameter if the second rotational speed is greater than the first rotational speed. In some embodiments, for example, when the polishing element 200 is mounted on the drive shaft 5 to allow relative radial movement, this relative radial movement further increases the size of the small track. Can be made. Thus, the movement of the drive shaft 5 and the polishing element can extend the scraping area and / or the polishing range of the polishing element beyond the small track 920.

  [0109] In certain embodiments, for example, where the polishing elements have ends having local centers of mass distributed opposite one another and away from the central axis of the drive shaft 5. Due to the rotation of the drive shaft 5 and the abrading element, a large trajectory 910 can be produced by centrifugal force (especially after sufficient space has been created in the lesion at high rotational speeds, eg 30,000 rpm or more). it can. Thus, the polishing elements disclosed herein can be configured such that the scraping area and / or the polishing area of the polishing element extends beyond the small track 920.

  [0110] FIGS. 10A-10B show a polishing element 300 according to a similar embodiment as described above. As shown, the polishing element 300 has two local centers of mass. The two local centers of mass are spaced apart (with approximate locations at 301 and 303) and are located at diagonal corners offset from the center of the flexible drive shaft 5. The polishing element 300 can comprise a substantially straight lumen extending from the proximal end 313 of the polishing element 30 to the distal end 311. The polishing element 300 may have a substantially cylindrical shape. The polishing element 300 may be attached to the drive shaft 5 as shown in FIG. 10A, such that the distal center of mass 301 is located above the longitudinal center of the drive shaft 5 and the proximal center of mass 303 is the drive. It is located below the longitudinal center of the shaft 5. Thus, when the polishing element 300 is rotated, the polishing range of the polishing element is increased over small trajectories, as described above. Further, as shown in FIG. 10B, the polishing element 300 has an effective diameter that is larger than the sheath 801 from which the polishing element 300 is deployed. The polishing element 300 can include curved edges to improve slidability of the device through tortuous paths and / or through the lumen.

  [0111] FIGS. 11-30 illustrate a polishing element 400 according to another embodiment. For example, as shown in FIG. 11, polishing element 400 comprises slotted tube 409 having at least two protrusions extending from polishing element 400. As shown, the protrusion comprises a two-part bead 405 attached to the polishing element 400. The polishing element 400 can have a distal end 411 and a proximal end 413. At least a portion of bead 405 comprises a roughened outer surface 407. Similar to the embodiments described above, the polishing element 400 may be coupled to the proximal portion of the flexible drive shaft 5. As described in more detail, the slotted tube 409 may be configured to compress, which allows the polishing element 400 to pass through the sheath for low profile transfer and expand during high speed rotation. The polishing range can be increased.

  [0112] FIG. 12 illustrates an exploded view of the polishing element 400. As shown, the two-part bead 405 comprises two molding halves having a roughened outermost surface 407. As shown, the two-part bead 405 is shaped such that the surface of the bead 405 facing the slotted tube 409 contacts the curved outer surface of the slotted tube 409. The two-part bead 405 is shaped so that the bead does not extend over and / or cover any portion of the slot 416. The bead 405 may be coupled to the slotted tube 409 by any suitable means. For example, bead 405 may be welded, glued, and / or fused to slotted tube 409. The bead 405 may be made of the same or different material as the tube 409. In some embodiments, the slotted tube 409 and bead 405 are made as one piece.

[0113] As shown in FIGS. 13-16, the slotted tube 409 can comprise a substantially cylindrical tube having a lumen 433 extending longitudinally therethrough. The slot 416 may be generally rectangular in shape and may extend radially through the tube 409 and communicate with the lumen 433. Tube 409 may be made of one or more materials that are sufficiently flexible to contract and / or expand under an applied force. In some embodiments, tube 409 can be configured to contract in size when an external force is applied and substantially return to its original shape and shape when the external force is removed. In some embodiments, the tube 409 can be configured to expand when an external force is applied and substantially return to its original shape and shape when the external force is removed.

  [0114] Figures 17-21 further show a bead 405. As shown, bead 405 includes a curved lower surface 440 having a shape that contacts the unslotted portion of slotted tube 409. The bead 405 comprises two beveled transition portions 445 and a central, generally cylindrical portion having a roughened surface 407. In some embodiments, the bead 405 has a shape that becomes thicker in a region of the slotted tube 409 that is further away from the slot 416. In some embodiments, the bead 405 is formed from a material that is relatively hard and / or dense as compared to the tube 409.

  [0115] As shown in FIG. 22, when the two-part bead 405 is coupled to the slotted tube 409, the mass of each half of the bead 405 is measured from the longitudinal center of the flexible drive shaft 5. Be separated. Therefore, the polishing element 400 comprises two local centers of mass, both offset from the longitudinal center of the flexible drive shaft 5. The local centers of mass of the polishing elements 400 are radially spaced apart, unlike the embodiments shown in FIGS. 1-10B, but the local centers of mass are not longitudinally spaced from each other. However, in some embodiments, the polishing element 400 can be configured such that this local center of mass is offset both radially and longitudinally. For example, the two bead elements 409 may not be symmetrically attached to the slotted tube 409. In other words, the first bead element may be coupled to the slotted tube 409 such that its most proximal end is positioned over the most proximal end of the slot 416, while , The second bead element may be coupled such that its most distal end is positioned over the most distal end of slot 416.

  [0116] As also shown in FIG. 22, the drive shaft 5 need not pass the entire length of the polishing element 400. Thus, the proximal end of the polishing element 400 may be secured to the distal end of the first drive shaft 5 and the distal end of the polishing element 400 may be near the portion of the second drive shaft 5. It may be fixed to the end portion. With the drive shaft removed from the center of the polishing element 400, the polishing element can be compressed and the two bead elements 409 can move toward each other, thereby causing the polishing element to have a low profile. Can be taken. In another embodiment, the drive shaft 5 passes the entire length of the polishing element.

  [0117] FIGS. 22-24 illustrate that the polishing element 400 can generally include a central polishing region 450 and proximal and distal attachment regions 455. Central polishing region 450 may be coupled to proximal and distal attachment regions 455 by tube gap region 460. Proximal and distal attachment regions 455 are portions of slotted tube 409 secured to flexible drive shaft 5 extending through lumen 433 of slotted tube 409. Proximal and distal attachment regions 455 may include welds and / or crimps or any other suitable securing means. Therefore, the proximal and distal attachment regions 455 are restrained from moving away from the flexible drive shaft 5. In embodiments where the drive shaft 5 passes the entire length of the polishing element, the drive shaft may be fixed in the mounting region 455, but not in the tube clearance region 460 and the central polishing region 450. Therefore, the tube gap region 460 and the central polishing region 450 are unrestrained and can move toward and / or away from the flexible drive shaft 5.

  [0118] FIGS. 25-30 illustrate example positions of the polishing element 400 attached to the flexible drive shaft 5. Polishing element 400 is shown in a stationary configuration in FIGS. The radial thickness of this unrestrained quiescent device is labeled as dl. Polishing element 400 is shown in a restrained configuration in FIGS. 26 and 28, the polishing element 400 is positioned within the sheath 801. In this constrained configuration, the radial thickness of the device is the thickness of the sheath 801, labeled as d2. As illustrated, the radial thickness d2 in the suppressed form is smaller than the radial thickness d1 in the non-suppressed form. In the restrained position, as shown in FIGS. 26 and 28, the slotted tube is compressed such that the slot has a width that is less than the width in the unrestrained configuration of FIGS. 25 and 29. In other words, the slotted tube 409 allows the polishing element 400 to be radially compressed. In this way, the polishing element 400 can have an effective diameter that is larger than the sheath 801 in which it is carried.

  [0119] In some embodiments, the polishing element 400 spontaneously returns to its unrestrained form in a relatively short time after being removed from the sheath 801. In other words, the material of the polishing element 400 is selected so that the slotted tube 409 will spring back to its unrestrained form as soon as the passive restraint exerted by the sheath is removed. In other embodiments, the polishing element 400 is rotated at a relatively low speed (eg, 5000 rpm or less) before returning to its unrestrained form.

  [0120] In FIGS. 27 and 30, the polishing element 400 is shown in an expanded configuration. For example, when the polishing element 400 is rotated at high speed, centrifugal forces cause the polishing element 400 to expand as the slotted tube 409 expands. That is, because the two-part bead 405 has a localized center of mass distributed away from the central axis of the slotted tube 409 and drive shaft 5, rotation also pulls the bead portion 405 away from the tube axis by centrifugal force. Therefore, the slotted tube 409 expands. Thus, when the polishing element 400 is rotated at high speed (eg, about 90,000 rpm or higher), the polishing element 400 can expand to a diameter d3 that is greater than d1 and d2. Therefore, the polishing area of the polishing element 400 extends beyond its non-inhibiting diameter d2. Although d3 is shown to be much larger than d2, it is understood that the diameter of polishing element 400 may not actually increase to such an extent when the device is rotated. The relative sizes of d1-d3 are merely to aid in an easy understanding of the functionality of the device and do not indicate the actual rate of expansion in use.

  [0121] In some embodiments, the polishing element 400 spontaneously returns to its unrestrained form in a relatively short time after it has stopped spinning. In other words, the material of the polishing element 400 is selected such that the slotted tube 409 returns to the unrestrained configuration as soon as the drive shaft 5 is stationary. In other embodiments, the polishing element 400 returns to a substantially unrestrained configuration as soon as the drive shaft 5 is stationary and transitions to a restrained configuration when retracted into the sheath 801.

[0122] The polishing element 400 has been shown and described as a two-piece bead 405 coupled to a slotted tube 409, although a unitary construction is also contemplated. Thus, in some embodiments, the slotted tube 409 can have thicker walls in the central region of the slotted tube 409 than the walls at its proximal and distal ends. At least a portion of the slotted tube can include a polished outer surface. In other words, the thickness of the walls on either side of the slot 416 can increase from the two ends of the slotted tube 409 to reach the thickness apex at the center of the slotted tube 409. The change in wall thickness can create two local centers of mass distributed away from the central axis of the slotted tube 409 and drive shaft 5. The change in wall thickness can form one or more protrusions that extend radially outward from the center of the polishing element. Thus, when the device is rotated at high speeds, centrifugal forces pull the two local centers of mass open the slots, causing the polishing element 400 to expand radially. Similarly, different masses of material can be used to create a slotted tube that expands when the slotted tube is rotated at high speed.

  [0123] FIGS. 31-36 illustrate a polishing element 500 according to another embodiment. Abrasive element 500 except that two-part bead 505 is configured to extend at least partially over slot 416 of slotted tube 409 when abrasive element 500 is unrestrained and at rest. Similar to polishing element 400.

  [0124] For example, as shown in FIGS. 31-34, the two-part bead 505 extends substantially over the slots of the slot 416 of the slotted tube 409 so that the two-part bead only with a small void 515. 505 is separated. For example, as shown in FIGS. 35A-35B, when constrained by a sheath 801 similar to the embodiment shown in FIG. 26, the two-part bead 505 is pressed together. Similar to the embodiment shown in FIGS. 27 and 30 described above, when the polishing element 500 is rotated at high speed as shown in FIGS. 36A-36B, the beads 505 are separated from each other by centrifugal force. It is forcibly released. Therefore, the diameter d3 of the polishing element 500 in operation is greater than the diameter d1 when the device is in its unrestrained configuration.

  [0125] FIGS. 37-47 illustrate a polishing element 600 according to another embodiment. For example, as shown in FIGS. 37-40, polishing element 600 includes slotted tube 509 with support rods 520 extending on opposite sides of slotted tube 509 over the longitudinal length of the slot, thereby providing two openings. Similar to polishing element 400 described above, except to create 516 and 517. The support rods 520 can help cure the polishing element 600. As shown in FIG. 42, the slotted tube 509 comprises a substantially cylindrical tube having a lumen 433 extending longitudinally therethrough.

  [0126] FIGS. 43-48 show various configurations of the polishing element 600 in use. Similar to FIGS. 26 and 35A, the polishing element 600 can be constrained to a smaller maximum diameter when an external force is applied, for example, to the two-part bead 405. As shown in FIG. 44, the slotted tube 509 may be compressed within the sheath 801, thereby reducing the radial width of the slotted tube 509. As explained above, the polishing element 600 can return to the unrestrained configuration when removed from the sheath 801 as shown in FIG. Similar to the embodiments illustrated in FIGS. 27, 30 and 36A and described above, the polishing element 600 can expand in diameter when rotated at high speed and when rotation is stopped. It is possible to return to the unsuppressed form.

  [0127] FIGS. 49-52 illustrate a polishing element 700 according to another embodiment, similar to the polishing element 400 (eg, as shown in FIG. 11) except that the two-part bead 705 has a different shape. Although the two-part bead 705 is shown as not extending over the slot 416 of the slotted tube 409, in some embodiments the two-part bead 705 extends at least partially or completely over the slot.

  [0128] Figures 53-56 show a polishing element 1000 according to another embodiment, similar to the polishing element 700, except that the bead 705 is longitudinally offset from each other. Therefore, as explained above, the polishing area of the polishing element 1000 extends beyond a small trajectory when the polishing element 1000 is rotated by the drive shaft 5.

[0129] The atherectomy system disclosed herein may be used, for example, in the following manner. A guidewire can be inserted into the patient and advanced over the area of interest. A rotatable drive shaft with an abrasive element attached to its proximal portion can be advanced over the guidewire. The rotatable drive shaft and polishing element can be advanced through the sheath. In some embodiments, the abrasive element expands radially when advanced out of the sheath. In some embodiments, the polishing element expands to a first diameter when rotated at a first speed and more than a first diameter when rotated at a second speed that is greater than the first speed. Expands to a larger second diameter. The polishing element can be advanced over the arterial lesion. The polishing element can be rotated to ablate the arterial lesion. Fluid may or may not be carried through the sheath. The arterial lesion may be excised and the abrasive element, drive shaft, sheath and guide wire may be removed from the patient. In some embodiments, the material is aspirated and the material is withdrawn through the drive shaft.

  [0130] One of ordinary skill in the art will appreciate that the disclosed aspects and features presented herein are not limited to any particular embodiment of the atherectomy system, but to one of the features described herein. Or, it will be appreciated that an atherectomy system comprising a plurality can be designed for use in a variety of medical procedures. Furthermore, those skilled in the art will recognize the interchangeability of various features from different embodiments. For example, the features of the polishing elements disclosed in various embodiments may be interchanged between embodiments. In addition to the variations described herein, other known equivalents of each feature may be mixed and combined by those of ordinary skill in the art to achieve polishing elements and atherectomy in accordance with the principles of the present invention. Techniques can be constructed.

  [0131] It should be understood, of course, that not all objects or advantages are necessarily achieved by any particular embodiment of the invention. Thus, for example, the present invention accomplishes or optimizes one advantage or group of advantages as taught herein, and achieves other objectives or advantages as necessarily taught or suggested herein. Those of ordinary skill in the art will recognize that they can be embodied or implemented in a manner that need not be done.

  [0132] Furthermore, although the present invention has been disclosed in the context of specific embodiments and examples, the present invention extends beyond the embodiments disclosed in detail to other alternative embodiments and / or inventions. It will be understood by a person skilled in the art that the use of and extends to its obvious modifications and equivalents. Therefore, it is intended that the scope of the invention herein disclosed should not be limited by the particular disclosed embodiments described above.

DESCRIPTION OF SYMBOLS 1 ... Rotary atherectomy system 3 ... Drive system 5 ... Drive shaft 30, 200, 300, 400, 500, 600, 700, 1000 ... Polishing element 201, 405, 505, 705 ... Ball edge 203, 433 ... Tube Cavity 205 ... Inclined end 207, 407 ... Outer surface 211, 311, 411 ... Distal end 213, 313, 413 ... Proximal end 221 ... Distal notch 223 ... Proximal notch 301 ... Distal mass center 303 ... Proximal mass center 409, 509 ... Slotted tube 416 ... Slot 440 ... Lower surface 445 ... Transition part 450 ... Central polishing area 455 ... Attachment area 460 ... Tube gap area 515 ... Void 516 ... Opening 520 ... Support rod 800 ... Welded part 801 ... Sheath 900 ... Blood vessels 910, 920 ... Orbit

Claims (7)

A device for atherectomy,
A flexible elongate rotatable drive shaft having a size and shape for insertion into a lumen and having flexibility;
An elongated tube having a radially expandable structure at a position between a distal end and a proximal end, the radially expandable structure comprising a slot extending through a side of the tube. And an elongated tube with
Each of the ends is coupled to the drive shaft,
The atherectomy device further comprises an abrasive element including a two-part bead disposed on the tube ,
An atherectomy device in which the two-part bead is distributed around the radially expandable structure. The atherectomy device according to claim 1 , wherein
Said Migaku Ken elements, by rotating the drive shaft, the two the two halves of the portion Welt away from each other, atherectomy device which is arranged to increase the width of the slot. The atherectomy device according to claim 1, wherein
It said polishing element is atherectomy device comprising tungsten. The atherectomy device according to claim 1, wherein
An atherectomy device in which the tube comprises nitinol. The atherectomy device according to claim 1, wherein
The atherectomy device, wherein the polishing element contains a material different from the material contained in the tube . The atherectomy device according to claim 1, wherein
Said Migaku Ken element, atherectomy device is solid. The atherectomy device according to claim 1 , wherein
An atherectomy device, wherein a rod extends from the proximal end of the slot to the distal end of the slot.

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