WO2016158475A1

WO2016158475A1 - Catheter

Info

Publication number: WO2016158475A1
Application number: PCT/JP2016/058621
Authority: WO
Inventors: 博文溝口
Original assignee: 株式会社グッドマン
Priority date: 2015-03-30
Filing date: 2016-03-18
Publication date: 2016-10-06
Also published as: KR20170127415A; CN107206205B; JP6727757B2; CN107206205A; JP2016187527A; KR102051722B1

Abstract

[Problem] To provide a monorail-type catheter having a novel structure whereby catching of a guide wire during withdrawal from a body lumen can be avoided. [Solution] A monorail-type catheter 10 in which a guide wire lumen 20 is formed in a distal-end portion 18 of a shaft 12, wherein an easy-tearing part 36 is provided in a peripheral wall part of the guide wire lumen 20, and when a guide wire catches during withdrawal of the catheter 10, the peripheral wall part is torn at the easy-tearing part 36 and the guide wire can separate to the outside from the guide wire lumen 20.

Description

catheter

The present invention relates to a catheter used in the medical field, and more particularly, to a monorail type catheter in which a guide wire lumen extending in a length direction is formed at a distal end portion of a shaft.

Conventionally, various catheters have been used in the medical field. For example, a user can insert a catheter into a body such as a blood vessel or an abdominal cavity to inject a drug solution, collect blood or body fluid, and perform treatment or examination with a device inserted into the body through the catheter. Specifically, for example, a treatment is performed to restore blood flow by inserting a catheter into a stenotic site of a blood vessel and expanding the stenotic site with a balloon provided at the distal end of the catheter.

Such a catheter is generally inserted into a body lumen such as a blood vessel percutaneously from the outside of the body, and is guided by a guide wire introduced into the lumen in advance to reach a position to be treated. Therefore, a guide wire lumen through which the guide wire is inserted is formed in the catheter. In addition to over-the-wire type catheters in which the guide wire lumen is formed over the entire length of the shaft, there are also known monorail type catheters such as a rapid exchange type in which the guide wire lumen is formed only at the tip of the shaft. ing. A monorail type catheter is disclosed in, for example, Japanese Patent Laid-Open No. 10-85339 (Patent Document 1).

In the monorail type catheter, the distal end port of the guide wire lumen is located on the distal end surface of the catheter, and the proximal end port of the guide wire lumen is located on the outer peripheral surface of the catheter. Thereby, the full length of a guide wire lumen becomes shorter than the full length of a catheter. Therefore, the catheter is configured so that the guide wire can be easily inserted and removed, and the length of the guide wire required for inserting and removing the catheter can be set short.

However, in the case of a monorail type catheter, when the guide wire is withdrawn from the state of being guided by the guide wire and inserted into the body lumen, the guide wire to be placed in the body lumen is in front of the proximal end port of the guide wire lumen. When it bends in the side, there was a possibility that it would be caught in the peripheral edge of the base end side port without smoothly entering the base end side port.

If such a guide wire is caught, it is inevitable that the operation of pulling out the catheter will be a major obstacle. In particular, in a state where the bent guide wire is strongly hooked, for example, in a loop shape, the catheter may not be pulled out. If the catheter is forcibly pulled out, it is conceivable that the catheter breaks starting from the vicinity of the proximal end port caught by the guide wire, and the distal end side is separated and dropped.

Japanese Patent Laid-Open No. 10-85339

Here, the present invention has been made in the background of the circumstances as described above, and the problem to be solved is a novel guide wire that can avoid the guide wire from being pulled out from the body lumen. It is to provide a monorail type catheter having a structure.

A first aspect of the present invention made to solve such a problem is a monorail type catheter in which a guide wire lumen extending in the longitudinal direction is formed at the distal end portion of the shaft, and the peripheral wall of the guide wire lumen The portion is formed with an easy-to-tear portion that is a portion having a smaller tear strength in the length direction than in the circumferential direction.

In the catheter having the structure according to this aspect, when the guide wire is hooked to the proximal end port of the guide wire lumen when being pulled out from the body lumen, the hooking force acting on the peripheral edge of the proximal end port is applied to the peripheral wall portion of the guide wire lumen. On the other hand, it acts as a cutting force and a spreading force. At that time, the peripheral wall portion of the guide wire lumen is provided with an easy tear portion which is expected to be torn and has a small tear strength. Open so that is cut open in the length direction. As a result, the hooked guide wire is allowed to be released from the guide wire lumen through the opened easy tear portion, and the guide wire is detached from the guide wire lumen through the easy tear portion.

Therefore, it is possible to prevent an excessive external force from being applied to the distal end portion of the catheter by the hooked guide wire, and to avoid a problem that the catheter is broken and only the distal end side is separated. Then, the guide wire can be easily pulled out of the body lumen independently of the guide wire by removing the guide wire from the guide wire lumen through the easy tear portion.

Therefore, in the catheter having the structure according to this aspect, the problem at the time of pulling out the catheter due to the hook of the guide wire can be avoided without impairing the advantages of the monorail type catheter as described above due to the shortening of the total length of the guide wire lumen. Therefore, good operability can be stably achieved.

In addition, it is desirable that the easy tearing portion in this aspect is formed substantially parallel to the central axis in the peripheral wall portion of the guide wire lumen, so that it can be more smoothly torn by an external force exerted when the guide wire lumen is caught. . However, an easy tearing portion may be provided in the length direction of the peripheral wall portion of the guidewire lumen in such a manner that the guidewire lumen is inclined, curved, bent, or the like with respect to the central axis of the guidewire lumen. Adjustments can be made.

According to a second aspect of the present invention, the easy tear portion includes a cut portion that is not penetrated in the wall thickness direction in the peripheral wall portion of the guide wire lumen.

In the catheter having the structure according to this aspect, the tear strength of the peripheral wall portion can be partially reduced by forming a slit of the not-cut portion in the wall thickness direction, and an easy tear portion can be formed. Further, in this aspect, since the cut portion is not penetrated, the tear resistance of the easy tear portion in the peripheral wall portion can be secured in the portion left unpenetrated, and the cut portion By adjusting the depth, it is possible to appropriately set the tear resistance of the easy tear portion.

In addition, the non-penetrating cut portion according to this aspect is formed by making a non-penetrated cut at a predetermined depth using a cutter or the like with respect to the peripheral wall portion of the guide wire lumen formed with a predetermined thickness, for example. However, as described in the following embodiment, it can be realized by forming a peripheral wall portion in a laminated structure in the thickness direction and forming a slit penetrating a specific layer portion in the thickness direction.

That is, according to a third aspect of the present invention, in the catheter according to the second aspect, an inner wall is a cylindrical member that forms the guide wire lumen, and a first slit that penetrates in the wall thickness direction is formed. A first tubular portion that is a tubular member, and a second tubular portion that covers the first tubular portion in a wall thickness direction with respect to the first tubular portion, and The cut portion is formed by covering the first slit with the second cylindrical portion.

By forming the first slit that penetrates only to the specific layer portion having the laminated structure in this way, the slit having a constant dimension in the thickness direction can be easily and stably formed in the peripheral wall portion of the guide wire lumen. It becomes possible to form with the dimension of the thickness direction. In addition, by providing cylindrical portions that do not have slits on both the inner peripheral surface and the outer peripheral surface of the layer in which the first slit is formed, and covering the slit, the opening of the slit is formed on the peripheral wall surface of the guide wire lumen. It is also possible to form without exposing.

According to a fourth aspect of the present invention, in the catheter according to any one of the first to third aspects, the tearable portion includes a second slit penetrating in a wall thickness direction in a peripheral wall portion of the guidewire lumen. It is a waste.

In the catheter having the structure according to this aspect, it is possible to more reliably form the easy tearing portion of the peripheral wall portion by providing the second slit penetrating in the wall thickness direction in the peripheral wall portion of the guide wire lumen. The second slit in this embodiment is formed over the entire length of the guide wire lumen, for example, and is maintained in a closed state in the normal state due to the elasticity and rigidity of the peripheral wall portion of the guide wire lumen. You may make it open the slit as an easy tearing part, when abnormal external force is exerted by the hook of a wire. Particularly preferably, the second slit in this embodiment can be formed in the following manner.

That is, according to a fifth aspect of the present invention, in the catheter according to the fourth aspect, the second slit is partially formed in the length direction of the peripheral wall portion of the guide wire lumen. .

In the catheter having the structure according to this aspect, there is a portion in which the second slit penetrating in the wall thickness direction is formed in the easy tear portion and a portion in which the second slit is not formed. The strength can be ensured at a portion where the second slit is not formed. It is also possible to appropriately set the tear resistance of the easy-to-tear part by adjusting the ratio of the length between the part where the second slit penetrating in the wall thickness direction is formed and the part where the second slit is not formed. It becomes.

In addition, the 2nd slit which penetrates the wall part which concerns on this aspect is a predetermined length which does not reach from the other end to the other end of the axial direction of a surrounding wall part other than being formed in perforation shape with a predetermined space | interval, for example It can be formed with an arbitrary length, number, shape, etc., such as an aspect extending in the length direction or an aspect extending in the axially intermediate portion of the peripheral wall portion. Moreover, the length of the peripheral wall portion includes a notch portion that does not penetrate the peripheral wall portion of the guide wire lumen according to the second aspect and a second slit that penetrates the peripheral wall portion of the guide wire lumen according to the fourth aspect. It is also possible to configure the easy-to-tear part by using it at different places in the direction.

A sixth aspect of the present invention is the catheter according to any one of the first to fifth aspects, wherein the proximal-side port of the guidewire lumen is in the peripheral wall portion of the guidewire lumen in the length direction. It includes a tapered opening edge that is a portion whose opening width becomes narrower toward the easy tearing portion.

In the catheter structured according to this aspect, the proximal-side port of the guide wire lumen includes a tapered opening edge that is a portion in which the opening width becomes narrower toward the easy tearing portion in the length direction of the shaft. The guide wire is guided in the proximal port toward the easy tearing portion. As a result, the tearing force due to the hooked guide wire acts efficiently on the easy tearing portion, and the guide wire detachment action due to tearing of the peripheral wall portion of the guide wire lumen is achieved more stably. Become.

According to a seventh aspect of the present invention, in the catheter according to any one of the first to sixth aspects, a balloon is provided on the distal end side of the shaft, and the proximal end port of the guidewire lumen is It is formed in the front end side rather than the said balloon.

The present invention can be applied to various monorail type catheters such as an ultrasonic diagnostic imaging catheter (IVUS), a suction catheter, and a microcatheter (penetration catheter), but particularly extends from the balloon to the distal end side as in this embodiment. However, the present invention can be advantageously applied to a balloon catheter in which a short guide wire lumen is formed only at the distal end portion of the catheter. In such a balloon catheter, a high degree of flexibility is required in consideration of the followability to the curved portion of the body lumen. Therefore, there is a problem of breakage and separation of the distal end portion due to the catch of the guide wire as described above. By applying the present invention to a catheter in which the catheter is likely to occur, it is possible to facilitate the catheter removal operation by detaching the hooked guide wire from the guide wire lumen while maintaining the flexibility of the distal end portion of the catheter. It is.

In the monorail type catheter structured according to the present invention, when the guide wire lumen is hooked to the proximal side port of the guide wire lumen when the catheter is pulled out from the body lumen, it is easy to tear on the peripheral wall portion of the guide wire lumen. The guide wire can be detached from the lumen out of the lumen. Therefore, an excessive external force action on the distal end portion of the catheter is avoided by the hooked guide wire, breakage separation of the distal end portion of the catheter is prevented, and the catheter can be easily pulled out.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the whole balloon catheter which is one Embodiment of this invention. The perspective view which expands and shows the principal part of the balloon catheter shown by FIG. The longitudinal cross-sectional view which expands and shows the front-end | tip part in which the guide wire lumen was formed in the balloon catheter shown by FIG. IV-IV sectional drawing in FIG. It is a model figure for demonstrating the structure of the tip tube which comprises the balloon catheter shown by FIG. 1, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view. The longitudinal cross-sectional view which shows another aspect of the tip tube shown by FIG. 5 as a model. It is a model figure which shows another aspect of the tip tube shown by FIG. 5, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view, (c) shows the application state to the front-end | tip part of a balloon catheter. FIG. It is a model figure which shows another aspect of the tip tube shown by FIG. 5, Comprising: (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view. It is a model figure which shows another aspect of the tip tube shown by FIG. 5, Comprising: (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view. It is a model figure which shows another aspect of the tip tube shown by FIG. 5, Comprising: (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view. The longitudinal cross-sectional view corresponding to FIG. 3 which expands and shows the front-end | tip part of the balloon catheter which is another embodiment of this invention. XII-XII sectional drawing in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an overall view of a balloon catheter 10 which is an embodiment of the catheter of the present invention. The balloon catheter 10 of the present embodiment is used for percutaneous angioplasty. Specifically, for example, the practitioner inserts the balloon catheter 10 into a lesion site of a stenotic or occluded blood vessel along a guide wire previously inserted into the blood vessel. The balloon catheter 10 is inserted into the blood vessel until the distal end side reaches a predetermined position. The practitioner can operate the balloon catheter 10 on the proximal end side, expand the lesion site of the blood vessel with the balloon provided on the distal end side, and perform a blood flow recovery treatment. The left side and the right side in FIG. 1 are the distal side and the proximal side of the balloon catheter 10, respectively.

More specifically, the balloon catheter 10 includes a shaft 12 having a predetermined length. A hub 14 is connected to the proximal end portion of the shaft 12. The proximal end is the proximal side of the operator. Near the tip of the shaft 12, a balloon 16 that can be expanded and deformed in the radial direction is provided. As described above, the basic structure of the balloon catheter 10 including the shaft 12, the hub 14, and the balloon 16 is publicly known as described in Patent Document 1.

A supply / discharge lumen extending from the hub 14 to the balloon 16 is formed inside the shaft 12. Then, the pressure fluid can be supplied to and discharged from the balloon 16 through the supply and discharge lumen from the external conduit connected to the hub 14. The balloon 16 can be expanded and contracted by the action of pressure fluid.

The distal end portion 18 of the shaft 12 protrudes further toward the distal end side by a predetermined length from the distal end side of the balloon 16. It is desirable that the distal end portion 18 is particularly soft and easily deformable because it easily hits the blood vessel wall when inserted into the blood vessel. Therefore, for example, a tip end made of a material softer than the main body portion of the shaft 12 may be fixed to the front end of the main body portion of the shaft 12. That is, the distal end portion 18 may be configured by integrally connecting the distal end tips.

As shown in FIG. 3, a guide wire lumen 20 is formed at the distal end portion 18 of the shaft 12 protruding from the balloon 16 toward the distal end side. The left side and the right side in FIG. 3 are the distal side and the proximal side of the balloon catheter 10, respectively. The guide wire lumen 20 extends in the length direction inside the distal end portion 18. The guide wire lumen 20 is a through hole extending between the distal end side port 22 and the proximal end port 24. The distal end side port 22 opens at the distal end surface of the shaft 12. The proximal end side port 24 is opened at the outer peripheral surface of the distal end portion 18 of the shaft 12. The proximal port 24 is formed on the distal side of the balloon 16.

That is, the guide wire lumen 20 of the present embodiment is formed only at the tip portion 18 protruding from the balloon 16 on the shaft 12. That is, the balloon catheter 10 is a monorail type catheter in which the guide wire is not inserted through the entire length of the shaft 12.

In this embodiment, the proximal end side port 24 of the guide wire lumen 20 is an opening that opens at the outer peripheral surface of the distal end portion 18 of the shaft 12 (see FIG. 2). The shape of the base end side port 24 is a shape in which the opening width becomes narrower from both sides and gradually becomes smaller from a predetermined position toward the distal end. Specifically, the proximal port 24 includes a tapered opening edge 26. The tapered opening edge 26 is an edge whose width becomes narrower toward the tip. As shown in FIG. 3, the peripheral edge portion of the base end side port 24 is inclined so as to become slightly higher from the base end side toward the front end side. Therefore, the height of the distal end of the tapered opening edge 26 is the highest among the height of the peripheral edge portion of the base end side port 24. The height corresponds to the shortest distance from the axis of the guide wire lumen 20. That is, the distal end of the tapered opening edge 26 is farthest from the axis of the guide wire lumen 20 in the peripheral edge portion of the proximal port 24.

Further, in the present embodiment, a distal end tube 30 is disposed at the distal end portion 18 of the shaft 12. The tip tube 30 is a straight tubular member (first tubular portion) extending in a substantially constant circular cross section. The distal end tube 30 extends from the distal end surface of the shaft 12 toward the proximal end side to the vicinity of the proximal end side port 24 of the guide wire lumen 20. An inner hole of the distal tube 30 forms a guide wire lumen 20.

Further, the tip portion 18 of the shaft 12 as the second cylindrical portion covers the tip tube 30 as the first cylindrical portion in the wall thickness direction. That is, the outer peripheral surface of the tip tube 30 is substantially entirely covered with the tip portion 18 of the shaft 12. Therefore, the portion where the tip portion 18 covers the tip tube 30 has a two-layered peripheral wall structure in which the tip tube 30 is an inner peripheral wall portion and the tip portion 18 of the shaft 12 is an outer peripheral wall portion. As described above, the peripheral wall portion of the guide wire lumen 20 includes a two-layer peripheral wall structure including the distal end tube 30 that is the inner peripheral wall portion and the distal end portion 18 that is the outer peripheral wall portion. The peripheral wall portion of such a laminated structure is formed by, for example, filling a predetermined cavity with a predetermined resin material in a molding cavity in which a tip tube 30 prepared in advance is set, and molding a resin layer on the outer peripheral surface of the tip tube 30. At the same time, it is obtained by forming the tip portion 18 in which the tip tube 30 is integrated.

The material forming the tip portion 18 of the shaft 12 and the material forming the tip tube 30 are not particularly limited. In addition to chemical resistance depending on the application, a soft synthetic resin material is preferably employed so that the flexibility required for the shaft tip as a whole and the tearability required in the present invention can be satisfied. Specifically, polyurethane resin, polyamide resin, polyolefin, or the like can be suitably used as a material for forming the tip portion 18 of the shaft 12 and the tip tube 30.

Referring to FIGS. 3 to 5, the easy tear portion 36 provided on the peripheral wall portion of the guide wire lumen 20 will be described. A notch-shaped slit 32 is formed in the cylindrical wall portion of the distal tube 30 arranged in the embedded state in the distal end portion 18 of the shaft 12. In particular, in the present embodiment, the slit 32 formed in the distal tube 30 is a first slit that penetrates the cylindrical wall portion of the distal tube 30 in the thickness direction (see FIG. 4). In the length direction of the distal tube 30, the slit 32 is partially formed with a shorter length than the distal tube 30 (see FIG. 3). Thereby, the slit non-formation part 34 is also left in the length direction of the distal end tube 30. The slit-unformed portion 34 is a portion where the slit 32 is not formed on an imaginary line extending along the slit 32.

More specifically, as shown in FIG. 5, in the length direction of the distal tube 30, a slit-like slit 32 extending a predetermined length from the distal end toward the proximal end side, and from the proximal end A notch-like slit 32 extending at a predetermined length is formed in the distal end tube 30. Between the two slits 32 in the length direction, there is a non-slit portion 34. Further, the proximal end side opening of the distal tube 30 is widened at the portion where the slit 32 is formed. The tapered opening edge 26 of the proximal end port 24 of the shaft 12 is located so as to enter the expanded portion.

Thus, the tip portion 18 of the shaft 12 constituting the peripheral wall portion of the guide wire lumen 20 has a two-layer structure, and a slit 32 is formed in the tip tube 30 that forms the one layer. By forming the slit 32 in the tip tube 30, the tear strength at the tip portion 18 is partially reduced at the circumferential position where the slit 32 is located. Thereby, the tip end portion 18 is easily torn along the slit 32 in the length direction. Thus, in the present embodiment, the easy-to-tear portion 36 that extends linearly in the axial direction along the

slits

32, 32 of the distal tube 30 is provided at the distal end portion 18 of the shaft 12.

Particularly in this embodiment, the slit 32 is formed on the periphery of the distal end portion 18 within a range where the proximal end port 24 of the guide wire lumen 20 is formed. That is, the proximal end port 24 is positioned on the extension line of the slit 32. The tapered opening edge 26 of the proximal end port 24 has a shape in which the opening width becomes narrower toward the slit 32. The tip of the tapered opening edge 26 is located on the extension line of the slit 32.

In order to perform a blood flow recovery treatment using such a balloon catheter 10, for example, the practitioner inserts a guide wire into the blood vessel percutaneously and guides the tip to the lesion site. Thereafter, the practitioner inserts the guide wire into the guide wire lumen 20 of the balloon catheter 10 from the proximal end side, and guides the balloon catheter along the guide wire to the lesion site in the blood vessel. Thereafter, a pressure fluid is supplied from the hub 14 through the supply / discharge lumen to the balloon 16 to be expanded. Thereby, the lesioned part of the blood vessel can be expanded. After the expansion treatment, the pressure fluid is discharged from the balloon 16 through the supply / discharge lumen 18 and contracted, and then the balloon catheter 10 is removed from the blood vessel.

Here, in the balloon catheter 10 of the present embodiment, when the balloon catheter 10 is extracted from the blood vessel, the guide wire 38 is bent in a loop shape or the like as shown by a virtual line (two-dot chain line) in FIG. The balloon catheter 10 cannot be removed from the guiding catheter (not shown) while being caught in the proximal port 24, or is broken in the transverse direction from the proximal port 24 and only the distal end portion 18 is left in the blood vessel. The problem of end up being avoided.

That is, when the guide wire 38 is bent and hooked on the proximal end port 24, the guide wire 38 is strongly pressed against the opening peripheral edge of the proximal end port 24 by the pulling force applied to the balloon catheter 10 from the outside. . This pushing force is exerted on the peripheral wall portion of the guide wire lumen 20 as an external force that pushes and tears the opening peripheral edge of the proximal end port 24 toward the distal end side. As a result, the peripheral wall portion of the guide wire lumen 20 is torn from the proximal end side toward the distal end side by the external force in the easy tear portion 36 whose tear strength is locally reduced on the circumference. At the same time, the guide wire 38 is detached from the guide wire lumen 20 through the tearing portion.

Then, in the peripheral wall portion of the guide wire lumen 20, the tearing portion gradually extends from the proximal end side port 24, and when the tearing portion reaches the distal end side port 22 and extends over the entire length, the guide wire 38 is detached from the guide wire lumen 20. Thereby, the hook of the guide wire 38 with respect to the balloon catheter 10 is completely eliminated. Therefore, the balloon catheter 20 can be easily pulled out from the blood vessel without being obstructed by the guide wire 38.

Particularly in the present embodiment, the distal end side peripheral portion of the proximal end side port 24 includes a tapered opening edge 26 whose opening width gradually decreases toward the tearing easy portion 36. Therefore, the pressing position of the guide wire 38 caught by the proximal end side port 24 is guided along the distal end opening edge 26 toward the distal end of the tapered opening edge 26. The tip of the tapered opening edge 26 is located on the extension line of the easy tear portion 36. In this way, the proximal end port 24 is formed so that the contact portion between the guide wire 38 and the proximal end port 24 is guided to a position close to the tearable portion 36. Then, the pressing force of the guide wire 38 against the peripheral edge portion of the proximal port 24 acts more efficiently and stably as the tearing force to the tearing easy portion 36. Thereby, the action of releasing the catch of the guide wire 38 can be stably exhibited.

Further, in the present embodiment, the slit-unformed portion 34 is left in the middle portion in the length direction of the tip tube 30 constituting the tip portion 18. It is also possible to adjust the tear strength at the tip portion 18 by changing the length of the slit non-formed portion 34.

Even if the slit-unformed portion 34 is present, the proximal end side is located between the ends of the

slits

32, 32 formed on both sides in the length direction and facing each other in the tearing direction. The tearing portion formed in the tip portion 18 along the slit 32 forming portion extends substantially linearly in the length direction and continues to grow until reaching the tip-side slit 32 forming portion located substantially on the extension line. It becomes.

In the present embodiment, the slit 32 is formed from the distal end opening of the distal tube 30 toward the proximal end. Thereby, the deformation rigidity of the distal end opening of the distal end tube 30, and hence the deformation rigidity of the distal end opening in the distal end portion 18 of the shaft 12, is set smaller by the slit 32. Thereby, it becomes easy to set the most distal end portion of the shaft 12 that is likely to hit the inner surface of the lumen such as a blood vessel softer than the proximal end side. In order to set the most distal end portion of the shaft 12 to be softer, a notch extending from the distal end opening portion of the distal tube 30 toward the proximal end side is separated from the slit 32 constituting the tear easy portion 36 described above. It is also possible to form it at an appropriate position above.

By the way, the above-described embodiment exemplifies one aspect of the easy tearing portion 36 in the tip portion 18 of the shaft 12 constituting the peripheral wall portion of the guide wire lumen 20. In the present invention, it is possible to employ various modes in which the tear strength of the tip portion 18 is reduced at a specific portion on the circumference. Some of the other embodiments will be exemplified below.

FIG. 6 exemplifies another aspect of the slit formed portion and the non-formed portion in the tip tube employed in the embodiment. That is, in the embodiment shown in FIG. 6, in the distal tube 40 having the same structure as that of the above embodiment, the slit 42 penetrating in the wall thickness direction has a predetermined length from the proximal side to the distal side in the axial direction. It is formed continuously. That is, in the distal tube 40 of this aspect, the slit 42 extends from the proximal end to the vicinity of the distal end in the axial direction, and the slit-unformed portion 44 extends from the distal end of the slit 42 to the distal end of the distal tube 40.

The tip tube 40 having such a configuration can also be used in place of the tip tube 30 described in the above embodiment. This form can also obtain the same operation effect as the above-mentioned embodiment. In particular, the distal tube 40 according to this aspect is provided with two slits extending from both sides in the axial direction because it is only necessary to form one slit 42 (first slit) extending from one side in the axial direction toward the other side. Further, the manufacture is also easier than the tip tube 30 of the above embodiment.

Further, FIG. 7 shows another embodiment of the distal tube 46 that can be employed in place of the distal tube employed in the embodiment. The tip tube 46 of this aspect has a substantially cylindrical shape over the entire length. The distal tube 46 is formed with a plurality of slits 48 (first slits) extending in the axial direction at substantially constant intervals. The plurality of slits 48 are formed on the same line. Each of the plurality of slits 48 has a predetermined length. Between the adjacent slits 48 among the plurality of slits 48, there is a slit-unformed portion 49 where no slit is formed. In other words, in this embodiment, the slits 48 and the non-slit portions 49 are alternately formed, and the easy tear portion is formed by a perforated slit.

The tip tube 46 having such a configuration can also be used in place of the tip tube 30 described in the above embodiment, as shown in FIG. Accordingly, as in the above-described embodiment, the easy tearing portion 36 extending in the length direction is formed in the peripheral wall portion of the guide wire lumen 20 in the portion where the slit 48 is intermittently formed, and the same action as in the above-described embodiment. The effect can be exhibited.

In this embodiment, since the slits 48 and the non-slit portions 49 are alternately positioned, the weak tearing portions and the strong portions are alternately positioned in the easy tearing portion. Therefore, when the peripheral wall portion of the guide wire lumen 20 is torn by the hooked guide wire 38, the operator who pulls out the balloon catheter 10 is more easily transmitted to the feel of tearing the easy tear portion. It is also possible to raise awareness of more prudent techniques by actively promoting the consciousness of the person. In the embodiment shown in FIG. 7, the lengths of the plurality of slits 48 are substantially the same. However, the lengths of the plurality of slits 48 may be different from each other.

By the way, when the slit forming part and the slit non-forming part are formed in the length direction of the distal end tube as in the above-described embodiment shown in FIGS. 1 to 5 and another aspect shown in FIGS. In the axial direction, it is desirable that the total length of the slit forming portions is larger than the total length of the slit non-forming portions. Thereby, when the guide wire 38 is hooked, the peripheral wall portion of the guide wire lumen 20 is torn more smoothly at the easy tear portion 36, and the guide wire 38 is detached.

FIG. 7C is a longitudinal sectional view corresponding to FIG. 3 in the above embodiment, and the members and parts having the same structure as in the above embodiment are the same as those in the above embodiment for easy understanding. The same reference numerals are given. FIGS. 7A and 7B are model diagrams corresponding to FIG. 5 in the above-described embodiment, in which characteristic components are enlarged in an easily understandable manner regardless of actual scales. . Furthermore, the proximal end side of the distal tube 46 of this aspect may have a tapered shape that is cut open and widened as in the embodiment shown in FIGS. 5 (a) and 5 (b). .

In addition, tip tubes of still another embodiment that can be employed instead of the tip tube 46 shown in FIG. 7 are shown in FIGS. 8 (a), (b), FIG. 9 (a), (b), and FIG. It is shown in (a) and (b).

In the distal tube 50 shown in FIGS. 8A and 8B, a slit 52 (first) extends continuously in the axial direction from the proximal end side to the distal end side through one place on the circumference in the wall thickness direction. 1 slit) is formed. That is, the tip tube 50 of this aspect is torn over the entire length by the slit 52. The slit 52 is covered with the tip portion 18 of the shaft 12 that forms the outer layer of the tip tube 50, thereby forming the easy tear portion 36.

9 (a) and 9 (b) is formed with a slit 58 formed at a depth not penetrating in the wall thickness direction from the inner peripheral surface toward the outer peripheral surface. The slit 58 continuously extends in the axial direction from the proximal end to the distal end of the distal tube 56. The outer peripheral surface of the distal tube 56 in which the slit 58 is formed is covered with the distal end portion 18 of the shaft 12 to form a two-layer structure, so that the easy tearing portion 36 is formed on the peripheral wall portion of the guide wire lumen 20. The

8 and 9, the easy-to-tear portion 36 is formed by

slits

52, 58 extending in a substantially constant cross section over the entire length in the axial direction. Therefore, the tear strength of the easy tear portion provided in the

tip tubes

50 and 56 is substantially constant over the entire length. Therefore, when the guide wire 38 is caught, the peripheral wall portion of the guide wire lumen 20 is torn more smoothly and stably along the easy tear portion 36, and the catch of the guide wire can be eliminated.

In the tip tube 56 shown in FIG. 9, the tear strength at the easy tear portion may change in the length direction. For example, the depth of the slit 58 in the wall thickness direction may be different in the length direction of the tip tube 56.

Further, the distal tube 60 shown in FIGS. 10A and 10B has a slit 62 (first slit) penetrating in the wall thickness direction in the axial direction as in the distal tube 50 shown in FIG. It is formed continuously over the entire length. Further, a substantially annular marker 64 is mounted on the outer periphery of the distal tube 60. The marker 64 is made of an X-ray opaque material such as platinum, for example, and has an appropriate axial length in consideration of visibility by X-rays during the treatment.

Further, the marker 64 is configured to be locked to the outer peripheral surface of the tip tube 60 by having a circumferential length exceeding a half circumference. The marker 64 is formed with an opening 66 divided at one place on the circumference. In a state where the marker 64 is attached to the tip tube, the opening 66 is located at the same position on the circumference with respect to the slit 62 of the tip tube 60.

The guide wire lumen is configured in a two-layer peripheral wall structure by covering the outer peripheral surface of the tip tube 60 to which the marker 64 is attached with the tip portion 18 of the shaft 12. As described above, the slit 62 and the opening 66 are located at the same position on the circumference. Therefore, the portion where the slit 62 and the opening 66 are located on the circumference has a smaller tear strength in the longitudinal direction than the other portions. As a result, when the guide wire is caught, a tearing portion extending from the slit 62 to the outer peripheral surface through the opening 66 of the marker 64 is formed so as to penetrate in the wall thickness direction in the peripheral wall portion of the guide wire lumen.

Therefore, the same effect as that of the above embodiment can be realized in the distal end portion 18 of the shaft 12 together with the mounting structure of the marker 64 that can be recognized by X-rays during the treatment. The effect similar to that of the above embodiment is that the easy-to-break portion 36 extending in the length direction is formed in the peripheral wall portion of the guide wire lumen 20 so that the guide wire can be quickly caught when the balloon catheter 10 is pulled out. This is the effect.

The slit structure of the tip tube 60 used in the embodiment shown in FIG. 10 is not limited to the illustrated one, and for example, the slit structure shown in FIGS. 5 to 9 may be used. In addition, the opening 66 may not necessarily be formed on the circumference of the marker 64 if a material or shape that can be easily broken is used. For example, a ring-shaped marker 64 that is cut by an external force exerted by the hooked guide wire 38 may be used. Furthermore, the specific shape and number of the markers 64 are not limited. For example, a plurality of markers may be attached along the length direction of the distal end tube 60.

As is clear from the above description, in each of the above-described embodiments, the

distal end tubes

30, 40, 46, 50, 56, and 60 in which the

slits

32, 42, 48, 52, 58, and 62 are formed are respectively connected to the distal end of the shaft 12. By covering with the portion 18, an easy tear portion 36 including a notched portion not penetrating in the wall thickness direction is formed in the peripheral wall portion of the guide wire lumen 20.

Further, the easy tearing portion 36 at the distal end portion 18 of the shaft 12 constituting the peripheral wall portion of the guide wire lumen 20 is easily realized by employing the

distal end tubes

30, 40, 46, 50, 56, 60 as described above. However, it can also be realized without using such a tip tube.

Specifically, the peripheral wall portion of the guide wire lumen 20 may be constituted by a tip portion 18 made of a single resin layer without using a tip tube. For example, as shown in FIGS. 11 to 12, a guide wire lumen is formed by forming a slit 70 extending in the length direction in the wall thickness direction from the outer peripheral wall of the tip portion 18 toward the inner peripheral wall in the length direction. It is also possible to constitute the easy tear portion 36 including a notched portion that is not penetrated in the wall thickness direction in the 20 peripheral wall portions. The slit 70 may be formed with a predetermined depth in the wall thickness direction from the inner peripheral wall of the distal end portion 18 toward the outer peripheral wall.

Further, also in the tip portion 18 formed of such a single layer, a slit (second slit) penetrating in the wall thickness direction is partially formed in the axial direction, or intermittently perforated in the axial direction. Alternatively, a slit (second slit) penetrating in the wall thickness direction may be formed over the entire length in the axial direction.

Furthermore, a marker 64 as shown in FIG. 10 may be attached to the peripheral wall portion of the guide wire lumen 20 at the tip portion 18 made of a single layer.

As described above, some of the other aspects of the embodiment of the present invention have been described in detail with reference to the drawings. However, the present invention is not construed as being limited in any way by the description regarding these specific aspect examples.

For example, the peripheral wall portion of the guide wire lumen may have a laminated structure of three or more layers. In this case, the easy tear portion may be provided by forming a slit in one or more of the plurality of layers of three or more layers.

Further, the specific aspect of the easy tearing portion in the peripheral wall portion of the guide wire lumen is not limited to the slit as illustrated. For example, when a reinforcing fiber such as a braided carbon fiber is made into a cylindrical shape and embedded in a peripheral wall portion, a guide wire is formed by forming a cut portion extending in a longitudinal direction at a predetermined position on the circumference in the cylindrical reinforcing fiber. It is also possible to constitute an easy tear portion including a not-cut portion that is not penetrated in the wall thickness direction in the peripheral wall portion of the lumen 20. Moreover, the tear easy part may be configured by a combination of a slit and a cutting part.

Alternatively, the circumferential direction can be obtained by blending short fibers oriented in the length direction with respect to the resin layer constituting the peripheral wall portion of the guide wire lumen, or by deflecting the arrangement direction of the resin molecular structure in the length direction. It is also possible to configure the easy tear portion by reducing the tear strength in the axial direction as compared with the above.

As can be understood from the above description, the easy tear portion in the catheter according to the present invention is configured by partially reducing the tear strength in the longitudinal direction on the peripheral wall portion of the guide wire lumen. It is desirable. However, the present invention is not limited to the aspect in which the easy tearing portion is formed only at the location specified on the circumference of the outer peripheral wall of the guide wire lumen 20. That is, as shown in the above-described embodiment or a plurality of other aspects, by setting the easy tearing portion at only one place on the circumference of the outer peripheral wall of the guide wire lumen 20, the site to be torn is specified. There are advantages such as being able to design. However, even when tearing easy parts are set at multiple locations on the circumference due to, for example, fiber orientation or molecular alignment, the external force that generally accompanies the guide wire lumen is concentrated on one location and tears at one location. Extends in the length direction. In addition, since the guide wire is released through the easy-to-tear part where tearing reaches the full length first, the intended guide wire releasing action can be effectively exhibited.

Moreover, tearing easy portions may be provided at a plurality of locations on the circumference. That is, a plurality of easy tearing portions may be provided on the peripheral wall portion of the guide wire lumen. In this case, even when the guide wire catching position is not planned, or when tearing at one easy-to-tear part is inhibited for some reason, the tearing action at the other easy-to-tear part is made fail-safe. It can also function. In that case, it is possible to rank the places where tearing occurs by providing a plurality of easy tearing portions so that the tear resistance strengths of the plurality of easy tearing portions are different from each other.

In the above embodiment, the present invention has been described using a balloon catheter as an example. However, the type of catheter need not be a balloon catheter. The catheter may be various monorail type catheters such as an ultrasonic diagnostic imaging catheter (IVUS), a suction catheter, and a microcatheter (penetration catheter).

Further, the tip portion 18 may be configured by, for example, a tip tip formed of a softer material than the main body portion of the shaft 12 being fixedly connected to the tip of the main body portion of the shaft 12 and integrally connected thereto. In this case, the guide wire lumen may be formed by the lumen of the tip. Specifically, the distal end side port may be formed at the distal end of the distal end tip, and the proximal end port may be formed at the outer peripheral wall of the distal end tip. Further, the peripheral wall structure of the tip may be composed of a single layer or a plurality of layers. When the peripheral wall structure of the tip is constituted by a plurality of layers, the materials forming each layer may be different from each other. Further, for example, the distal end portion 18 may be configured by joining a two-layered cylindrical member in which the easy tear portion 36 is formed only in the inner layer to the distal end of the catheter. In this case, the guide wire lumen may be formed in a two-layered cylindrical member. For example, the distal end port of the guide wire lumen is formed on the distal end surface of a two-layered cylindrical member. The proximal end port of the guide wire lumen is formed on the outer peripheral surface of the two-layered cylindrical member.

The shape of the proximal end port of the guide wire lumen may be, for example, a polygonal shape such as a rectangular shape or a triangular shape, or a circular shape such as an ellipse. Further, the proximal port may not include a tapered opening edge. For example, the width of the opening edge of the proximal port may be constant in the length direction. In the above embodiment, the tip of the tapered opening edge 26 is located on the extension line of the slit 32. However, the tip of the tapered opening edge 26 may not be located on the extension line of the slit 32. For example, the tip of the tapered opening edge 26 may be separated from the extension line of the slit 32 by a predetermined distance.

In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

10: balloon catheter, 12: shaft, 18: distal end portion, 20: guide wire lumen, 22: distal end port, 24: proximal end port, 26: tapered opening edge, 30, 40, 46, 50, 56, 60 : End tube, 32, 42, 48, 52, 58, 62, 70: Slit, 34, 44, 49: Slit-unformed part, 36: Easy tear part, 38: Guide wire, 64: Marker, 66: Opening part

Claims

A monorail type catheter in which a guide wire lumen extending in the length direction is formed on the tip portion of the shaft,
A catheter having an easy tear portion, which is a portion having a smaller tear strength in the longitudinal direction than the circumferential direction, is formed on the peripheral wall portion of the guide wire lumen.
The catheter according to claim 1, wherein the tear-easy portion includes a cut portion that is not penetrated in a wall thickness direction in a peripheral wall portion of the guide wire lumen.
A first tubular portion, an inner wall of which is a tubular member forming the guide wire lumen, and is a tubular member formed with a first slit penetrating in the wall thickness direction;
A second tubular portion covering the first tubular portion in a wall thickness direction with respect to the first tubular portion, and
The catheter according to claim 2, wherein the cut portion is formed by covering the first slit with the second cylindrical portion.
The catheter according to any one of claims 1 to 3, wherein the tearable portion includes a second slit penetrating in a wall thickness direction in a peripheral wall portion of the guidewire lumen.
The catheter according to claim 4, wherein the second slit is partially formed in a length direction of a peripheral wall portion of the guide wire lumen.
The proximal-side port of the guide wire lumen includes a tapered opening edge that is a portion whose opening width becomes narrower toward the easy tearing portion in the peripheral wall portion of the guide wire lumen in the length direction. The catheter according to any one of 5.
A balloon is provided on the distal end side of the shaft;
The catheter according to any one of claims 1 to 6, wherein a proximal end port of the guidewire lumen is formed on a distal end side with respect to the balloon.