JP6046892B2 - Infusion catheter - Google Patents

Description

  The present invention relates to an infusion catheter for injecting a desired substance through a tubular organ to a required location in a living body.

  In general, there are various problems in the treatment of living bodies accompanied by surgical operations. For example, a patient to be treated must endure a long-time operation, and an operator is forced to concentrate nerves for a long time, and the risk of infection is relatively high. Recently, in order to alleviate such various burdens and to perform necessary operations more safely and simply, catheters, guide wires, stents, and other various medical devices have been developed and put into practical use. ing.

  For example, recent advances in medical devices such as balloon catheters have led to the implementation of endovascular treatment that approaches the desired affected area from within the blood vessel, especially ischemic heart diseases such as angina pectoris and myocardial infarction. It has come to be applied to many treatments.

  However, once treated, blood vessels once clogged tend to be “restenosis” that clogs again, and endovascular treatment using a balloon catheter had to be repeated.

  Therefore, a device called DES (Drug Eluting Stent), in which a stent and a drug that suppresses the growth of smooth muscle cells were applied to the stent, appeared, and the restenosis rate in treatment with only a balloon catheter was 30% to 40%. However, with the advent of stents, it became 20% to 30% and was reduced to 10% by DES. However, the occurrence of “stent thrombosis”, in which thrombus occurs and blood vessels are clogged, is a problem.

  Under such circumstances, it is required that the restenosis rate is low and stent thrombosis does not occur. For this purpose, it is necessary to reduce the restenosis rate without using a stent. As a device having a required function, an infusion catheter capable of locally administering a drug to an affected area without placing a foreign substance in the body is known.

  For example, Patent Document 1 discloses a balloon catheter in which a conduit through which a drug passes is arranged on the outer surface of a balloon and a hole is formed in the outer wall of the conduit, so that the drug can be released from the hole. It is supposed to be configured. However, in the balloon catheter of Patent Document 1, for example, when the target site is locally hard and the blood vessel inner diameter of a part of the lesioned part is small, it is difficult to release the drug from the minute hole ahead of it. It is difficult to release the drug evenly from the minute holes.

Japanese National Patent Publication No. 11-503039

  This invention is made | formed in view of the subject which the said prior art has, and provides the infusion catheter which can apply | coat a chemical | medical agent equally to a lesioned part.

  As a result of intensive studies based on the above problems, the present inventors have found that a balloon catheter having an inner balloon and an outer balloon having a minute hole has a structure that inhibits adhesion between the inner balloon and the outer balloon. As a result, it was found that the drug can be released uniformly from all the minute holes, and the present invention has been completed. That is, the present invention has an inner balloon, an outer balloon having a minute hole, and a structure that inhibits adhesion between the inner balloon and the outer balloon, and has a minute space between the inner balloon and the outer balloon. The present invention relates to an infusion catheter.

  The present invention also relates to an infusion catheter characterized in that adhesion is inhibited by the presence of microfibers between the inner balloon and the outer balloon.

  The present invention also relates to an infusion catheter, wherein the minute space is an infusion channel.

  The present invention also relates to an infusion catheter characterized in that the stenosis can be expanded by expanding the inner balloon.

  The present invention also relates to the infusion catheter, wherein the inner balloon is entirely located inside the outer balloon.

  According to the infusion catheter of the present invention, since there is a minute space between the inner balloon and the outer balloon at any time, the drug can be evenly released from all the minute holes. Even when the blood vessel inner diameter of a part of the part is small, the medicine can be evenly applied to the lesioned part.

1 is an overall view of an infusion catheter of the present invention. 1 is an overall view (partially sectional view) of an infusion catheter of the present invention. It is detail drawing of the infusion catheter balloon part of this invention. It is detail drawing of an inner side balloon. It is a figure which shows the state which has arrange | positioned the fiber between balloons (microfiber) to the inner side balloon. It is a detailed sectional view of a balloon part. It is detail drawing of a guide wire opening part and a base end part. It is sectional drawing of the axial direction in (A) of FIG. It is sectional drawing of the axial direction in (B) of FIG. It is sectional drawing of the axial direction in (C) of FIG.

  The present invention relates to an infusion catheter having an inner balloon and an outer balloon having a minute hole, and having a minute space between the inner balloon and the outer balloon.

  The infusion catheter of the present invention relates to a high-speed exchange type (RX type) catheter in which a guide wire passing tube 16 is disposed only on the distal side of the infusion catheter as shown in FIGS. It is. 1 and 2 show the entire infusion catheter of the present invention, but there are a hub 40, a proximal tube 30, a distal tube 20, and a balloon 10 in this order from the proximal side.

  The balloon 10 has a double structure of an outer balloon 12 and an inner balloon 14 each having a minute hole. As shown in FIG. 6, both the outer balloon 12 and the inner balloon 14 are connected to a guide wire passing tube 16 on the distal side. It is bonded by heat fusion or an adhesive. On the proximal side, the outer balloon 12 is bonded to the outer tube 25 and the inner tube 26 of the distal end tube 20 respectively by heat fusion or adhesive.

  In this way, three lumens are formed in the distal end tube 20. Although the embodiment of FIG. 7 shows an example of a coaxial structure, these lumens can be arranged in a parallel structure. One lumen is a guide wire lumen in which the distal side is joined to the proximal side of the guide wire passing tube 16 and a guide wire port is formed on the proximal side, and one lumen is located on the proximal side of the inner balloon 14 on the distal side. And the proximal side is joined to the distal side of the proximal tube 30, and the other lumen is joined to the proximal side of the outer balloon 12 and the proximal side is proximal. This is an infusion lumen formed by being joined to the distal side of the part tube 30. The guide wire lumen is a passage for passing a metal wire called a guide wire that guides the balloon catheter, the inflation lumen is a passage for liquid to inflate the balloon, and the infusion lumen is a passage for drug to pass .

  The hand tube 30 is a two-hole tube having two lumens. Although the embodiment of FIG. 7 shows an example of a coaxial structure, it can be arranged in a parallel structure. The proximal tube is formed to extend the two lumens of the distal tube 20, the inflation lumen and the infusion lumen. The first lumen of the hand tube is formed by joining the distal side with the inflation lumen on the proximal side of the tip tube 20 and joining the proximal side of the first lumen with the distal side of the hub 40, and connecting the inflation lumen to the hub. It is extended to 40. The second lumen of the proximal tube is formed by joining the distal side with the infusion lumen on the proximal side of the tip tube 20 and joining the proximal side of the second lumen with the distal side of the hub 40, and the infusion lumen. Is extended to the hub 40. When connecting the hub 40 and the hand tube, a strain relief 39 may be provided as shown in the figure.

  The hub 40 has one opening on the distal side, and two openings (7C and 7D) on the proximal side.

  As shown in FIGS. 2 and 7, a core wire 32 is disposed in the distal end tube 20 and the proximal tube 30 for the purpose of increasing the rigidity of the distal side of the infusion catheter. Further, as shown in FIG. 6, a position marker 18 exists in the guide wire passing tube 16 in the inner balloon 14.

  The material of the distal end tube 20, the proximal tube 30, and the guide wire passing tube 16 is not particularly limited. That is, polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer and the like can be used.

  The material of the core wire 32 is stainless steel, C—Mn—Si—PS—Cr—Mo—Ni—Fe—X (X = Au, Os, Pd, Re, Ta, Ir, Ru) alloy, C—Mn. -Si-PS-Cr-Mo-Ni-X (X = Au, Os, Pd, Re, Ta, Ir, Ru) alloy, copper, nickel, titanium, piano wire, Co-Cr alloy, Ni-Ti Various alloys such as alloys, Ni—Ti—Co alloys, Ni—Al alloys, Cu—Zn alloys, Cu—Zn—X alloys (for example, X = Be, Si, Sn, Al, Ga), amorphous alloys, etc. Metal wires are used, and among these materials, stainless steel is preferable because it has an appropriate rigidity and is not workable, economical, or toxic. The core wire 32 is preferably tapered so that it gradually becomes thinner in the region of the proximal tube 30 and has a constant diameter in the region of the distal tube 20.

  As the material of the position marker 18, it is preferable to use a metal having high radiopacity such as platinum or gold.

  The inner balloon 14 of the present invention is fixed to the distal end of the tip tube 20 and the distal end of the guide wire passing tube 16. A tip opening is provided at the tip of the guide wire passing tube 16. The inner balloon 14 can be inflated and deflated by adjusting the internal pressure. As a manufacturing method of the inner balloon 14, there are dipping molding, blow molding and the like, and an appropriate method can be selected according to the use application of the medical balloon catheter. In particular, in the case of a medical balloon catheter for the purpose of expanding and treating a stenosis of a blood vessel or a body cavity, blow molding is preferable in order to obtain sufficient pressure resistance. For example, a tubular parison having an arbitrary size is first formed by extrusion molding or the like. The tubular parison is placed in a mold having a mold that matches the balloon shape, and stretched in the axial direction and the radial direction by a biaxial stretching process, thereby forming a balloon having the same shape as the mold. In addition, the said biaxial stretching process may be performed on heating conditions, and may be performed in multiple times. Further, the stretching in the axial direction may be performed simultaneously with or before or after the stretching in the radial direction. Furthermore, in order to stabilize the shape and dimensions of the balloon, the balloon may be annealed. As shown in FIGS. 4 to 6, the inner balloon 14 has a straight tube portion 14a and a sleeve portion 14b for liquid-tight bonding on the distal and proximal sides thereof, and between the straight tube portion and the bonded portion. Has a tapered portion 14c. The dimensions of the inner balloon 14 are determined by the intended use of the medical balloon catheter, but the outer diameter of the straight tube portion 14a when expanded by adjusting the internal pressure is 1.50 to 35.00 mm, preferably 1. The length of the straight pipe portion 14a is 10.00 to 80.00 mm, preferably 10.00 to 60.00 mm. The resin material of the tubular parison is not particularly limited. For example, polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane and polyurethane elastomer can be used, and two types of these resin materials can be used. You may have the multilayer material by the blend material which mixed the above, or 2 or more types of lamination | stacking. It is preferable that the stenosis in the blood vessel can be expanded.

  As shown in FIGS. 1 to 3, the microhole 13 of the present invention is preferably disposed in the straight tube portion of the outer balloon and has a diameter of 1 to 50 μm. Further, as a method for producing the minute hole 13 in the outer balloon 12, it is preferable to use a laser capable of fine processing before the inner balloon 14 is disposed inside the outer balloon 12.

  The outer balloon 12 of the present invention is fixed to the distal end of the tip tube 20 and the distal end of the guide wire passing tube 16. The performance, material, and manufacturing method of the outer balloon 12 may be the same as those of the inner balloon 14, but it is preferable that expansion of the inner balloon 14 is not significantly hindered when the inner balloon 14 is expanded. It is preferable to have a plurality of minute holes 13 in the straight pipe portion as shown in FIG.

  As the microspace 15 of the present invention, the distance between the outer surface of the inner balloon 14 and the inner surface of the outer balloon 12 is preferably 2 to 100 μm in the radial direction. In particular, it is preferable to create a microspace 15 by disposing interfiber balloon fibers (microfibers) between the outer balloon 12 and the inner balloon 14, but the present invention is not limited thereto. Microprojections or microgrooves may be disposed on the inner surface or the outer surface of the inner balloon or both.

  For example, the infusion catheter of the present invention expands the lesioned part by expanding the inner balloon 14 after placing the balloon part in a target site, for example, a stenotic vascular lesioned part, and presses the outer balloon 12 against the vascular wall. Next, by applying pressure between the outer balloon 12 and the inner balloon 14 using a drug, the drug oozes out from the microhole 13 and can be applied to the blood vessel wall.

  The infusion catheter of the present invention is used in the same manner as a known infusion catheter. However, for example, when the target location is locally hard and the blood vessel inner diameter of a part of the lesioned portion is small, the infusion catheter is smaller than that. Although it is difficult to release the drug from the hole and the drug cannot be released evenly from all the minute holes, the infusion catheter of the present invention always has a minute space 15 between the inner balloon 14 and the outer balloon 12. Therefore, the drug can be released from all the minute holes 13 evenly.

  Hereinafter, the present invention will be described with reference to the drawings showing one embodiment of the present invention (however, the present invention is not limited to this one embodiment, and various modifications are made without departing from the spirit of the present invention). Is possible.)

  1 and 2 are views showing an overall view of an infusion catheter according to an embodiment of the present invention. As shown in FIG. 6, the balloon portion of the infusion catheter is composed of an inner balloon 14, an outer balloon 12, and an inter-balloon fiber 23. The inner tube (guide wire passage tube) 16, the tip tube 20, and the proximal portion Tubes 30 are connected to each other. These connections were made to be joined by welding. There are three connection points: the balloon tip side, the balloon proximal side, and the distal shaft proximal side. On the balloon distal side, the inner balloon sleeve portion 14b, the outer balloon sleeve portion 12b, the inter-balloon fiber 23, and the inner tube 16 are connected. At the balloon proximal side, the inner balloon sleeve 14b is connected to the inner tube 23 of the proximal tube, and the inter-balloon fiber 230 and the outer balloon sleeve 12b are connected to the outer tube 23 of the proximal tube. ing. The proximal end portion of the distal end tube 20 is connected to the distal end portion 30 of the proximal portion tube, and a proximal opening 7B of the guide wire lumen is formed in the vicinity of the connection portion.

  FIG. 8a shows a cross-sectional view of the balloon portion. The inner balloon 14, the outer balloon 12, the inter-balloon fiber 23, and the inner tube 16 shown in FIG. 8 a have a coaxial structure in the order of the inner tube 16, the inner balloon 14, the inter-balloon fiber 23, and the outer balloon 12 from the inside. The inner balloon 14 and the outer balloon 12 were manufactured by the following method similar to that of the balloon of the existing balloon catheter. By forming a polyamide elastomer tube-shaped parison by extrusion molding, placing the tube-shaped parison in a mold having a mold that matches the balloon shape, and stretching it in the axial direction and the radial direction by a biaxial stretching process Then, a balloon having the same shape as the mold is formed. The mold has a diameter of 2.5 mm for the inner balloon 14 and a length of 15 mm, and a diameter for the outer balloon 12 of 3.0 mm and a length of 20 mm. Further, the outer balloon 12 was manufactured by laser machining of 4 micro holes 222 having a diameter of 10 μm, 5 in the circumferential direction and 5 in the axial direction in total. As shown in FIG. 5, the inter-balloon fiber 23 is arranged so as to cover the outer side of the inner balloon 14 by being connected at the front end side of the balloon, and further, by covering the outer balloon 12 from above, the inner balloon 14 and the outer balloon 14 are disposed. Arranged between balloons 12.

  FIG. 8 b shows a cross-sectional view of the tip tube 20. An inner tube (guide wire tube) 16 is disposed in the distal shaft tube shown in FIG. 8b, and a guide wire lumen 70, an inflation lumen 50, and an infusion lumen 60 are formed. The structure is a coaxial structure, which is a guide wire lumen 70, an inflation lumen 50, and an infusion lumen 60 in this order from the inside.

  FIG. 8 c shows a cross-sectional view of the hand tube 30. In the hand tube 30 shown in FIG. 8c, an inflation lumen 50 and an infusion lumen 60 are formed. The structure is a coaxial structure, and the inflation lumen 50 and the infusion lumen 60 are in this order from the inside. A hub is joined to the proximal end and communicates with the inflation lumen 50 and the infusion lumen 60.

  The inner balloon 14, the outer balloon 12, the inter-balloon fiber 23, the inner tube 16, and the tip tube 20 may be made of any material, but were made using a heat-weldable resin material. The hand tube 30 may be made of any material, but was made using a heat-weldable resin material and metal material.

  As a comparative example, a structure in which the inter-balloon fiber 23 was removed from the structure of the above example was produced.

  In order to evaluate the prepared Examples and Comparative Examples, a narrowed constriction model with a small diameter was prepared, and the Examples and Comparative Examples were expanded within the stenosis model, and the drug was not blocked by the small diameter portion. It was verified whether or not can be applied evenly. In order to confirm how the drug came out, red ink that was easy to observe was used instead of the drug.

  The comparative example was placed in the constriction stenosis model, and the outer balloon was gradually pressurized with 8 atm (recommended pressure) applied to the inner balloon. Infusion started at 2 atm, and the proximal side of the constriction stenosis model was distant. It was infused only on the back side. At the small diameter part, the outer balloon wrinkled, and it seemed to flow along the wrinkled part to the proximal side and the distal side. For this reason, it was confirmed that the red ink did not spread between the balloons.

  With the example placed in a constricted stenosis model, with 8atm (recommended pressure) applied to the inner balloon, the outer balloon was gradually pressurized, and before reaching 1atm, red ink was scattered all over the balloon, 1atm Occasionally, infusion was initiated, and it was confirmed that the entire balloon was infused and applied to the entire constricted stenosis model.

  As mentioned above, the Example can discharge | release a chemical | medical agent equally from all the microholes from a comparative example.

7A. Tip side guide wire lumen opening 7B. 9. Proximal guide wire lumen opening Balloon 12. Outer balloon 12a. Outer balloon straight tube 12b. Outer balloon sleeve portion 12c. 12. Outer balloon taper part Micro hole 14. Inner balloon 14a. Inner balloon straight tube 14b. Inner balloon sleeve 14c. Inner balloon taper 15. Microspace 16. Guide wire passing tube 18. Position marker 20. Tip tube 23. Inter-balloon fiber 25. Outer tube of tip tube 26. Inner tube of tip tube 30. Hand tube 32. Core wire 39. Strain relief 40. Hub 50. Inflation lumen 60. Infusion lumen 70. Guide wire lumen

Claims (6)

The outer balloon and inner balloon have a double structure,
An inner balloon,
An outer balloon having a microhole;
Having a structure that inhibits adhesion between the inner balloon and the outer balloon;
An infusion catheter having a minute space extending in the entire circumferential direction between the inner balloon and the outer balloon.   The infusion catheter according to claim 1, wherein adhesion is inhibited by the presence of microfibers between the inner balloon and the outer balloon. The infusion catheter according to claim 2, wherein the microfibers are arranged along the shape of the inner balloon over the entire length of the space between the inner balloon and the outer balloon. The infusion catheter according to any one of claims 1 to 3, wherein the minute space is an infusion channel. The infusion catheter according to any one of claims 1 to 4 , wherein the stenosis can be expanded by expanding the inner balloon. The infusion catheter according to any one of claims 1 to 5 , wherein the inner balloon is located entirely inside the outer balloon.