JP2008000276A - Expansion body of catheter and expansion catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter having a flexible expansion body with improved expansibility with respect to an affected area which can be easily inserted into the highly curved lumen of the living body. <P>SOLUTION: The expansion body of a catheter comprises a straight pipe section and a joint section to be attached to a shaft of a catheter. The expansion body has a plurality of stress concentration elements arranged on the outer circumferential surface thereof along the longitudinal direction of the straight pipe section. When the expansion body expands, the stress concentration elements move in a direction separating from a longitudinal central axis of the straight pipe section. At least a part of the plurality of stress concentration elements are arranged scatteringly along the central axis of the straight pipe section. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an expansion body and an expansion catheter used in a surgery for the purpose of expanding a living body lumen.

  The dilatation catheter is mainly used for a living lumen forming treatment for a living lumen such as a stenotic or occluded blood vessel. In general, an expansion catheter has an expansion body communicating with an expansion lumen for supplying pressure fluid at a distal end portion of a tubular catheter shaft having a plurality of lumens therein, and a port communicating with each lumen at a proximal end portion. In the normal state, the expansion body is folded with respect to the catheter shaft. In this treatment, the dilatation body of the dilatation catheter is inserted into the stenosis site, where it is dilated by introducing pressure fluid into the dilatation body, and the stenosis or occluded affected area is expanded.

  However, in this dilatation treatment, there is a case where excessive damage is simultaneously caused to a tissue of a living body lumen such as a blood vessel. That is, in this expansion treatment, a biological lumen such as a blood vessel is expanded while being torn by pressurization from the inside, and at that time, excessive stress and friction are applied to the tissue of the biological lumen wall. In that case, due to excessive wounding, a state such as acute occlusion or thrombosis immediately after dilation, or reocclusion due to tissue proliferation caused by the wound in the chronic phase may occur.

  In order to remedy this drawback, a plurality of atheromas that are directly attached to the outer surface of the expansion body and the expansion body for the purpose of reducing stress applied to the tissue of the body lumen wall such as blood vessels during dilatation treatment An expansion catheter composed of an incision device (a metal blade attached to an expansion body with polyurethane adhesive) is shown in Patent Document 1 and is effective in actual clinical practice.

  However, the dilatation catheter composed of the dilatation body shown in this Patent Document 1 and a plurality of atherectomy devices attached to the outer surface of the dilatation body is an adhesive to a long atherectomy device extending over the entire dilation body. However, there is a drawback that the flexibility of the expanded body portion is mainly poor due to an increase in hardness due to the adhesive after the fixing. Blood vessels such as coronary arteries in which this catheter is used are often highly bent, and there is a problem that if the flexibility of the expansion body is poor, the intended affected area cannot be reached.

  Patent Document 2 discloses a catheter that includes a flexible elongated element on a balloon and forms a longitudinal axial channel (cut) in a lesion. One object of the prior art is that the flexible elongated elements function flexibly to facilitate passage through tortuous blood vessels. As a method of flexibly functioning a flexible elongated element, the element has a plurality of cutout portions, and the cutout portions are filled with a soft material. However, in this case, there is a disadvantage that the lesion portion cannot be stably expanded because the cut portion of the lesion portion cannot contact with the cut portion. Furthermore, since the cut-out portion is filled with a soft material, the strength of the element itself is lowered, and there is a possibility that the flexible elongated element is broken or broken when passing through the bent portion.

Patent Document 3 discloses a catheter having a plurality of blade segments attached to a base member on a balloon, and a part of each blade segment is juxtaposed with another blade segment. In this prior art, the blade segments are juxtaposed to improve the flexibility of the catheter rather than placing a long continuous blade on the balloon. However, since the base member is provided on the balloon and the blade segments are juxtaposed, the flexibility of the blade segments in the lateral direction is deteriorated.
JP-A-5-293176 JP 2005-517474 A JP-T-2005-507683

  In view of these circumstances, the problem to be solved by the present invention is to improve the expandability of the expansion body with respect to the lesioned part and to have the flexibility of the expansion body portion, and to be easily inserted into a highly bent biological lumen It is to provide an expandable body and a catheter.

  The present invention is a catheter expansion body having a straight tube portion and a joint portion that is bonded to a catheter shaft, and the catheter expansion body is formed in the longitudinal direction of the straight tube portion as the expansion body expands. A plurality of stress concentration elements arranged on the outer peripheral surface of the expansion body along the longitudinal direction of the straight pipe portion, moving in a direction away from the central axis, and at least included in the plurality of stress concentration elements Some of the stress concentration elements are distributed over the central axis direction of the straight pipe portion. According to these structures, the expandability of the expansion body with respect to the lesioned portion is improved, and the expansion body portion has flexibility, and can be easily inserted into a highly bent biological lumen.

  Further, it is preferable that the at least some stress concentration elements are arranged at different circumferential positions with respect to the central axis of the straight pipe portion. According to this structure, the expandability of the expansion body and the flexibility of the expansion body portion can be further improved.

  The at least some stress concentration elements are preferably arranged so that at least a part of the stress concentration elements are arranged in parallel in the circumferential direction of the straight pipe portion, and the circumferential direction of the straight pipe portion More preferably, the length of at least one parallel portion of the stress concentration elements parallel to each other is ½ or less of the longitudinal length of the at least one stress concentration element parallel. According to these structures, the expandability of the expansion body and the flexibility of the expansion body portion can be further improved.

  In addition, it is preferable that the at least some stress concentration elements include only one other stress concentration element that is parallel to the circumferential direction of the straight pipe portion with respect to at least a part of the stress concentration elements. According to this structure, it is possible to further improve the flexibility of the expansion body portion.

  Further, the at least some stress concentration elements include other stress concentration elements parallel to the circumferential direction of the straight pipe portion with respect to at least a part of the stress concentration elements existing at one end of the straight pipe portion. While there is only one, there are two or more other stress concentration elements juxtaposed in the circumferential direction of the straight pipe portion with respect to at least a part of the stress concentration elements existing at the other end of the straight pipe portion. It is preferable to do. According to this structure, it is possible to have different properties of the expandability of the expansion body and the flexibility of the expansion body portion at each end of the straight pipe portion.

  Each of the stress concentration elements included in the plurality of stress concentration elements has different circumferential positions on the basis of the central axis of the straight pipe portion, and has circumferential portion lengths at regular intervals. It is preferable that they are arranged at separated positions. According to this structure, the expandability of the expansion body can be further improved.

  Moreover, it is preferable that the length in the longitudinal direction of each stress concentration element included in the plurality of stress concentration elements is the same. According to this structure, the number of members is reduced, and the expanded body can be easily manufactured.

  Moreover, it is preferable that the cross-sectional shape of at least a part of the stress concentration element is circular. According to this structure, the lesioned part can be stably expanded and can be used more safely.

  In addition, it is preferable that a cross-sectional shape of at least a part of the stress concentration element is a taper shape that gradually decreases in a direction away from the straight pipe portion, and is the outermost circumferential direction of the straight pipe portion of the stress concentration element. More preferably, at least part of the tip is a blade. According to this structure, the expandability of the expansion body can be further improved.

  Moreover, it is preferable to provide a protective member for protecting the blade. According to this structure, the extended body can be used more safely.

  Another feature of the present invention is a catheter having the shaft to which the catheter expansion body is joined.

  Other features of the present invention and their effects will become apparent from the following embodiments and drawings.

  As described above, the catheter expansion body according to the present invention includes a plurality of stress concentration elements arranged on the outer peripheral surface of the expansion body along the longitudinal direction of the straight tube portion. Since at least some of the stress concentration elements included are distributed over the central axis direction of the straight pipe portion, the expandability of the expansion body with respect to the lesioned portion is improved, and the flexibility of the expansion body portion is increased. It can be easily inserted into a highly bent biological lumen.

  EMBODIMENT OF THE INVENTION Below, the expansion body for catheters and catheter which concern on this invention are demonstrated based on embodiment. The present invention is a catheter expansion body (balloon) having a straight tube portion and a joint portion that is bonded to a catheter shaft, and the catheter expansion body is formed by the expansion of the expansion body. A plurality of stress concentration elements arranged on the outer peripheral surface of the expansion body along the longitudinal direction of the straight pipe portion, moving in a direction away from the central axis in the longitudinal direction of At least some of the stress concentration elements included are distributed over the central axis direction of the straight pipe part (or divided over the central axis direction, or discontinuously arranged over the central axis direction). The catheter expansion body is provided. According to these structures, the expandability of the expansion body with respect to the lesioned portion is improved, and the expansion body portion has flexibility, and can be easily inserted into a highly bent biological lumen.

1. Prior Art FIG. 1 is a side view of a prior art having a plurality of stress concentration elements 103 (blades) on the surface of an expansion body 101, FIG. 2 is a cross-sectional view of the expansion body, and FIG. Show. Referring to FIGS. 1 and 3, it can be seen that the stress concentration element 103 in the prior art is arranged in a state where the end portion is aligned with the central axis direction of the straight tube portion 102. As a result, the cross section of the straight pipe portion 102 is in a state in which a plurality (three in the figure) of stress concentration elements 103 are arranged at any position as shown in FIG. 2, and the flexibility of the expansion body 101 is poor. Thus, when the flexibility of the expansion body 101 part is bad, there exists a problem that it cannot reach the target affected part.

2. One embodiment of expansion body for catheter (expansion body 201: FIGS. 4-6, expansion body 301: FIG. 7)
One embodiment of the “catheter expansion body” according to the present invention is shown in FIG. The expansion body 201 includes a straight pipe portion 202 and stress concentration elements 203 (203A, 203B, 203C, 203D, and 203E). The stress concentration element 203 moves away from the central axis as the expansion body 201 expands. It is supposed to move. FIG. 5 shows a development view of the straight pipe portion 202 of this embodiment. Referring to FIG. 5, it can be seen that one end of each of the stress concentration elements 203A, 203B, and 203C is arranged in a distributed manner with the end of the other stress concentration elements in the same direction. In other words, the stress concentrating element includes a proximal end plane perpendicular to the longitudinal central axis of the straight tube portion of the expansion body including the proximal end of the stress concentrating element, and a distal end of the stress concentrating element. A distal end plane perpendicular to the longitudinal central axis of the straight tube portion of the expansion body, wherein the proximal end plane of at least some of the stress concentrating elements is a different plane, or of at least some of the stress concentrating elements It can also be expressed that the distal end plane is a different plane. With these structures, the length of each stress concentrating element can be made shorter than that of the prior art, and the flexibility of the expanded body 201 can be improved as compared with the prior art. Furthermore, referring to FIG. 6, which is a cross-sectional view of the expansion body 201 in FIG. 4 taken along the line AA, there are only two stress concentration elements 203A and 203D in the AA cross section. Thus, since the cross section with few stress concentration elements (the cross section in which one or two stress concentration elements exist in this embodiment) works like a joint in the entire expansion body 201, such a cross section becomes the expansion body 201. It is clear that the flexibility is further improved as compared with the prior art.

  The number of stress concentration elements, the length in the longitudinal direction, and the position should be such that at least some of the stress concentration elements of the plurality of stress concentration elements are dispersed and arranged over the central axis direction of the straight pipe portion (see FIG. The stress concentration element 203 such as 4) is not particularly limited. These can be designed in consideration of the balance between extensibility and flexibility of the expansion body. As in the embodiment shown in FIG. 5, the length of each stress concentration element 203 may be different. Further, a plurality of them may be arranged at the same circumferential position with reference to the central axis of the straight pipe portion 202, such as 203A and 203B and 203D and 203E.

  The stress concentration elements may be arranged only at the same circumferential position as in another embodiment of the expansion body according to the present invention shown in FIG. However, in this embodiment, since the stress concentration element 303 (303A, 303B) exists only in one direction of the expansion body 301, in the case of an eccentric lesion, the stress concentration element 303 does not contact the lesion part well. there is a possibility. In this embodiment, there is a space between the stress concentration elements 303A and 303B, and there is a portion where the stress concentration element does not contact the lesion when the expansion body 301 is expanded. Therefore, from the viewpoint of further improving the expandability of the expansion body, the stress concentration elements 203A, 203C, and 203D of the embodiment shown in FIGS. 4 to 6 are different from each other based on the central axis of the straight pipe portion 202. It is preferable that a stress concentration element is disposed at the circumferential position. However, the embodiment shown in FIG. 7 can be suitably used for a predetermined lesion part such as a case where the lesion part is not eccentric.

  Further, it is preferable that the stress concentration elements arranged at the different circumferential positions are partially arranged in the circumferential direction so that there is no interval in the longitudinal direction (“at least a part of the stress concentration elements is the straight pipe portion”). Corresponding to “Arranged in parallel in the circumferential direction”). In FIG. 5, a part (204A) of stress concentration elements 203A, 203C and 203D and a part (204B) of 203B, 203C and 203E are arranged in parallel in the circumferential direction. By having such parallel portions 204A and 204B, the stress concentration element exists over almost the entire length of the straight pipe portion 202. The stress concentration element is brought into contact with the lesioned portion without any gap, and the expandability of the expansion body 201 is increased. Can be further improved. By improving the expandability of the expansion body, it is possible to lower the expansion pressure for expanding the expansion body when expanding the same lesion. If the dilation pressure can be reduced, the possibility of the rupture of the dilatation body during the procedure can be reduced, and further, adverse effects on the normal living body lumen around the lesion can be suppressed.

3. One embodiment of expansion body for catheter (expansion body 401: FIGS. 8 to 9)
FIG. 8 shows another embodiment according to the present invention, and FIG. 9 shows a developed view of the straight pipe portion. Similar to the embodiment of FIGS. 4 to 6, the expansion body 401 includes a straight pipe portion 402, a stress concentration element 403 (403 </ b> A, 403 </ b> B, 403 </ b> C, 403 </ b> D), and a parallel portion 404 (404 </ b> A, 404 </ b> B). In this embodiment, there is only one other stress concentration element 403C in parallel with respect to a part of the stress concentration element 403B existing at one end portion (right side of the drawing) of the straight pipe portion 402 (parallel portion 404B). For a part of the stress concentration element 403A existing at the other end (the left side of the drawing) of the straight pipe portion 402, there are two other stress concentration elements 403C and 403D in parallel (parallel portion 404A). The relationship between each of these stress concentration elements 403 is that “at least a part of the stress concentration elements existing at one end of the straight pipe portion is one other stress concentration element parallel to the circumferential direction of the straight pipe portion. The concept is that there are two or more other stress concentration elements juxtaposed in the circumferential direction of the straight pipe portion with respect to at least a part of the stress concentration elements existing at the other end of the straight pipe portion. include.

  As the number of stress concentration elements arranged in parallel increases, the expandability of the expansion body at that portion improves, and as the number of stress concentration elements decreases, the flexibility at that portion increases. As shown in this embodiment, by controlling the number of parallel stress concentration elements 403 at each end of the straight pipe portion 402, it is possible to have different properties at each end of the straight pipe portion 402. Become. For example, there are two other stress concentrating elements in parallel (parallel portion 404A) with the end on the proximal side of the catheter and the other (parallel portion 404B) on the distal side. Insertability can be improved.

4). One embodiment of expansion body for catheter (expansion body 501: FIGS. 10-13, expansion body 601: FIG. 14)
FIG. 10 shows another embodiment according to the present invention, and FIG. 11 shows a developed view of the straight pipe portion. Similar to the embodiment of FIGS. 4 to 6, the expansion body 501 includes a straight pipe portion 502, a stress concentration element 503 (503 </ b> A, 503 </ b> C, 503 </ b> E), and a parallel portion 504 (504 </ b> A, 504 </ b> B). In the present embodiment, a part of the stress concentration element 503A and a part of the parallel part 504A of 503C, and a part of the stress concentration element 503C and a part of the parallel part 504B of 503E, each of the other stress concentration elements parallel to each other are 1 There is only one. The relationship between each of these stress concentration elements 503 is as follows: “At least some of the stress concentration elements are in addition to other stress concentration elements parallel to the circumferential direction of the straight pipe portion with respect to at least a part of the stress concentration elements. Included in the concept of “only one”. This is because one stress concentration element different from the stress concentration element intersects with the proximal end plane of at least one stress concentration element excluding the proximal end plane of the stress concentration element present at the most proximal side. In other words, it can only be said. In addition, there is only one other stress concentration element different from the stress concentration element that intersects the distal end plane of at least one stress concentration element except the distal end plane of the stress concentration element present at the most distal side. It can be said that it exists.

  Since one stress concentration element exists in a cross section of the expanded body, the expandability of the expanded body is remarkably improved. In addition, when more extensibility is required, high extensibility can be obtained by expanding a plurality of times. Furthermore, since the stress concentration element can be brought into contact with the other part of the lesioned part by rotating and then expanding the expansion body, higher expandability can be obtained.

  Referring to FIG. 12, which is a cross-sectional view taken along the BB cross section of the expansion body, and FIG. 13, which is a cross-sectional view taken along the CC cross section, there is only one stress concentration element 503 </ b> A in the BB cross section. There are only two stress concentration elements 503A and 503C in the cross section. The presence of many stress concentration elements in a cross section of the expansion body deteriorates the flexibility of the expansion body. Therefore, it is clear that this embodiment has improved flexibility over the prior art. In this way, there is only one other stress concentration element that is parallel to a part of the stress concentration element (or there is no other stress concentration element that is parallel to a part), so the expandability and flexibility of the expansion body It becomes possible to optimize the balance of sex.

Further, it is preferable that the parallel portion is ½ or less of the longitudinal length of the parallel stress concentration elements (“at least one parallel portion of the stress concentration elements parallel to the circumferential direction of the straight pipe portion”). The length corresponds to “1/2 or less of the longitudinal length of at least one stress concentration element in parallel”). The parallel portions 504A and 504B of the stress concentration element 503 have two stress concentration elements 503 as in the CC cross section, and the cross section of the other portion has only one stress concentration element 503 as in the BB cross section. Since it does not exist, the BB cross section is more flexible. Therefore, about the parallel part 504 which has CC cross section, it becomes possible to improve a softness | flexibility more because it is 1/2 or less of the longitudinal direction length of the stress concentration element 503. FIG.
It is preferable that the circumferential distances D and E between the stress concentration elements 503 are all the same (“each stress concentration element included in the plurality of stress concentration elements is based on the central axis of the straight pipe portion). Corresponding to “disposed at different circumferential positions and spaced apart from each other by a certain circumferential length”). With this structure, the expandability of the expansion body 501 can be further improved.

  Moreover, the length of the stress concentration element 503 in the longitudinal direction can be made uniform by making all the stress concentration elements 503 on the expansion body 501 the same length, and manufacturing is facilitated.

  The cross-sectional shape of the stress concentration element is not particularly limited as long as the stress concentration element has a shape and a size that can concentrate stress during expansion on a lesioned part as compared with the size of the expansion body. Since the expandability of the expansion body improves as the stress concentration becomes more conspicuous, the taper shape is preferably such that it gradually narrows away from the straight pipe portion of the expansion body. In order to improve the expandability of the expansion body, any structure may be used as long as the tip of the tapered shape comes into contact with the lesion when the expansion body is expanded, and it may be a triangle as shown in FIG. 6 or FIG. In addition, only a portion away from the expansion body of the stress concentration element 603 may have a tapered shape. Moreover, in order to concentrate stress | extremely extremely, the taper-shaped front-end | tip part of the stress concentration element 603 may be a blade or a blade. By adopting such a structure, it becomes possible to further improve the expandability of the expansion body.

  Particularly in the case where the stress concentration element 603 has a blade or a structure having a blade, a protective member 605 that sandwiches the stress concentration element 603 from both sides as shown in FIG. It is preferable to provide. The protective member 605 is preferably made of a resin containing a rubber material, and more preferably a thermoplastic elastomer material such as a polyamide elastomer. By including such a protective member 605, it is possible to reduce damage to a normal living body lumen when the expansion body 601 is inserted into the lesioned part or removed from the lesioned part 601. Since the outer circumferential portion of the protective member 605 is not joined to the stress concentration element 603, when the expansion body 601 is expanded, the distal end portion is opened by the pressure of the expansion body 601, and the stress concentration element 603 comes into contact with the lesion. Does not prevent you from doing.

5. One embodiment of expansion body for catheter (expansion body 701: FIGS. 15 and 16)
FIG. 15 shows another embodiment according to the present invention, and FIG. 16 shows a cross-sectional view taken along the line FF. The expansion body 701 includes a straight pipe portion 702 and a stress concentration element 703 (703A, 703C, 703E), and the cross section of the stress concentration element is circular. By making the cross section of the stress concentration element 703 circular, there is no problem in any state of the stress concentration element 703 when the expansion body 701 is expanded, and stable expandability of the expansion body 701 can be exhibited. It becomes possible. In addition, since the surface of the stress concentration element 703 that contacts the expansion body 701 is circular, the influence of the stress concentration element 703 on the expansion body 701 (such as a decrease in pressure resistance due to damage or the like) can be reduced. Furthermore, the possibility of damage to the stress concentration element 703 itself can be reduced. Therefore, troubles during the procedure can be reduced, and the operator can perform the procedure with peace of mind.

6). One embodiment of expansion body for catheter (expansion body 801: FIG. 17)
The stress concentration element may be joined to the surface of the expansion body directly or via a base, and extended from the vicinity of both ends of the expansion body 801 as shown in FIG. 17 in order to improve flexibility. It may be held by the support member 806. Bonding between the stress concentration element and the surface of the expansion body and bonding between the stress concentration element 803 and the support member 806 are performed by a method well known to those skilled in the art (adhesion, welding, etc.). The support member 806 is preferably composed of a flexible member such as rubber. According to this structure, when the expansion body 801 contracts, the support member 806 is disposed along the surface of the expansion body 801 without sagging. Therefore, when the expansion body 801 is pulled out from the body, it can be pulled out without applying excessive resistance, and the risk of the stress concentration element 803 being damaged or dropped off can be avoided.

7). Material of Stress Concentrating Element The material of the stress concentrating element (including the above “blade” and “blade”) described in the above embodiments is not particularly limited, but in order to further improve the expandability of the expansion body Is preferably a metal, and more preferably stainless steel. Further, in order to place importance on flexibility, it is preferably a superelastic metal, more preferably a Ni—Ti alloy. In consideration of the balance between expandability and flexibility of the expansion body, the stress concentration element may have a plurality of through holes.

8). Catheter to which catheter expansion body is joined The expansion body according to the present invention is usually used by being joined near the distal end of the catheter shaft. The catheter to be joined is not particularly limited, and may be an over-the-wire type in which the guide wire lumen exists over the entire length of the catheter, or a rapid exchange type in which the guide wire lumen exists only at the distal end portion of the catheter. The outer diameter of the straight tube portion when it is expanded is not particularly limited. However, when treating a blood vessel or the like below the coronary artery or the knee, about 2 to 4 mm is preferable. When treating a blood vessel etc., about 4-9 mm is preferable. Moreover, it is preferable that the longitudinal direction length of an expansion body is about 10-50 mm in a straight pipe part. The longer the straight pipe part is, the greater the effect of dispersing and arranging the stress concentration elements. The longitudinal length of the stress concentration element is 1/3 to 1/5 of the straight pipe part, and is about 3 to 10 mm. Preferably there is. In this case, it is preferable that the parallel part of the stress concentration elements is about 1 to 2 mm.

  The number of stress concentration elements, the length in the longitudinal direction, the position, and the shape of each embodiment described above can be changed by means well known to those skilled in the art. For example, all the stress concentration elements included in the expansion body may be the same as any one of the embodiments, or some stress concentration elements included in the expansion body may be the same as any one of the embodiments. Good. In addition, it is also possible to create an extension that combines any of the features of the above-described embodiments.

  Hereinafter, examples and comparative examples of the expansion body according to the present invention will be described in detail, but the following examples do not limit the present invention.

(Example 1)
Expanded body made of polyamide elastomer in which the length of the straight pipe portion is 12 mm, the expanded outer diameter is 3.0 mm, the proximal sleeve inner diameter is 0.90 mm, and the distal sleeve inner diameter is 0.60 mm Was used (Shore hardness 72D). Three triangular prisms made of SUS440, having an isosceles triangular cross section with a base of 0.3 mm and a height of 0.2 mm, and a longitudinal length of 4 mm were used as stress concentration elements. The bottom surface of this stress concentration element was joined to the surface of the expanded body using urethane adhesive.

  One stress concentrating element is joined at a position 1 mm away from the proximal end of the straight pipe section, the expansion body is rotated by 120 °, one is joined at a position 4 mm away from the proximal end, and the expansion body is further joined by 120 °. Rotated and joined one at a position 8 mm away from the proximal end. Therefore, the length of the parallel portion of each stress concentration element is 1 mm (see FIGS. 10 to 13).

  The outer tube is a polyamide elastomer tube (Shore hardness 72D) having an inner diameter of 0.71 mm, an outer diameter of 0.88 mm, and a length of 400 mm. The inner tube is a polyamide having an inner diameter of 0.43 mm, an outer diameter of 0.56 mm, and a length of 435 mm. An elastomer tube (Shore hardness 72D) was used. The distal end of the outer tube and the proximal sleeve of the expansion body were joined together by the thermal welding of the distal end of the inner tube and the distal sleeve of the expansion body. The proximal end of the outer tube and the proximal end of the inner tube were each joined to a polycarbonate hub using urethane adhesive to produce a catheter having an expansion shown in FIG.

(Example 2)
Four triangular prisms similar to Example 1 and one triangular prism having a longitudinal length of 8 mm were used as stress concentration elements. Similar to Example 1, the bottom surface of the stress concentration element was joined to the surface of the expanded body using urethane adhesive. The stress concentrating element joins a triangular prism having a longitudinal length of 4 mm at a position 1 mm away from the proximal end of the straight pipe portion, and further has a longitudinal length of 4 mm at a position 2 mm away from the distal end of the triangular prism. Another triangular prism was joined. The expansion body was rotated 120 °, and a triangular prism having a longitudinal length of 8 mm was joined at a position 2 mm away from the proximal end. Further, the expansion body is rotated 120 °, and one triangular prism having a longitudinal length of 4 mm is joined at a position 1 mm away from the proximal end, and the remaining one is joined at a position 2 mm away from the distal end of the triangular pillar. (See FIGS. 4 to 6). The length of the parallel portion of each stress concentration element is 3 mm.

  Other portions were produced in the same manner as in Example 1 to produce a catheter having an expanded body shown in FIG.

(Example 3)
Three triangular prisms similar to those in Example 1 and one triangular prism having a longitudinal length of 8 mm were used as stress concentration elements. Similar to Example 1, the bottom surface of the stress concentration element was joined to the surface of the expanded body using urethane adhesive. The stress concentrating element joins a triangular prism having a longitudinal length of 4 mm at a position 1 mm away from the proximal end of the straight pipe portion, and further has a longitudinal length of 4 mm at a position 2 mm away from the distal end of the triangular prism. Another triangular prism was joined. The expansion body was rotated 120 °, and a triangular prism having a longitudinal length of 8 mm was joined at a position 2 mm away from the proximal end. Further, the expansion body was rotated 120 °, and one triangular prism having a longitudinal length of 4 mm was joined at a position 1 mm away from the proximal end (see FIGS. 8 and 9). The length of the parallel portion of each stress concentration element is 3 mm.

  Other parts were the same as in Example 1, and a catheter having an expanded body shown in FIG. 8 was produced.

(Comparative Example 1)
Three triangular prisms made of SUS440, having a base of an isosceles triangle with a base of 0.3 mm and a height of 0.2 mm, and a longitudinal length of 10 mm were used as stress concentration elements. Similar to Example 1, the bottom surface of the stress concentration element was joined to the surface of the expanded body using urethane adhesive. For the stress concentration element, one triangular prism was joined at a position 1 mm away from the proximal end of the straight pipe portion, the expansion body was rotated 120 °, and one triangular prism was joined at a position 1 mm away from the proximal end. Further, the expansion body was rotated 120 °, and one triangular prism was joined at a position 1 mm away from the proximal end. Other parts were the same as in Example 1, and a catheter having an expanded body shown in FIG. 1 was produced.

(Evaluation)
FIG. 18 is a schematic view of a bending plate used for evaluation. A bending plate 11 simulating a blood vessel was placed in a water tank filled with physiological saline at 37 ° C., and a polyethylene tube 12 was placed on the bending plate 11. The polyethylene tube 12 is composed of a straight portion 13 and a bent portion 14, the length of the straight portion 13 is 60 mm, the radius of curvature of the bent portion 14 is 10 mm, the outer diameter 15 of the polyethylene tube 12 is 5 mm, and the inner diameter 16 is 3 mm. is there. A 0.014 ″ guide wire was inserted in advance into the polyethylene tube 12. The end of the guide wire was placed at a position 50 mm from the end of the bending plate 11.

  An inflation device was attached to the hub at the proximal end of the catheter, and evaluation was performed in a state where the expansion body was contracted by reducing the pressure. The operability when the catheter was inserted along the guide wire from the entrance of the bending plate 11 was evaluated. When the proximal end of the catheter was held by hand and it could be advanced to the end of the bending plate 11, it was evaluated as passing, and when the catheter kink or the like occurred in the middle, it was evaluated as non-passing. The evaluation results are shown in Table 1.

この評価により、カテーテルを体内へ挿入する際の操作性が評価できる。実施例１から３は通過時の抵抗に差は感じたものの、全て屈曲部を通過し、良好なカテーテル操作性を示した。これに対して、比較例１は屈曲部を通過する際にかなりの抵抗を感じ、カテーテルの近位側でキンクが生じ、不通過となった。

By this evaluation, the operability when inserting the catheter into the body can be evaluated. Although Examples 1 to 3 felt a difference in resistance during passage, they all passed through the bent portion and showed good catheter operability. On the other hand, Comparative Example 1 felt considerable resistance when passing through the bent portion, and kink occurred on the proximal side of the catheter, and it did not pass.

FIG. 1 is a side view of a prior art expansion body. FIG. 2 is a cross-sectional view of a straight tube portion of an expansion body according to the prior art. FIG. 3 is a developed view of the straight pipe portion of the expansion body of the prior art. FIG. 4 is a side view of an embodiment of the expansion body according to the present invention. FIG. 5 is a development view of the straight pipe portion of one embodiment of the expansion body according to the present invention. FIG. 6 is a cross-sectional view taken along the line AA of one embodiment of the expansion body according to the present invention. FIG. 7 is a side view of an embodiment of the expansion body according to the present invention. FIG. 8 is a side view of an embodiment of the expansion body according to the present invention. FIG. 9 is a development view of the straight pipe portion of one embodiment of the expansion body according to the present invention. FIG. 10 is a side view of an embodiment of the expansion body according to the present invention. FIG. 11 is a development view of the straight pipe portion of one embodiment of the expansion body according to the present invention. FIG. 12 is a cross-sectional view taken along the line B-B of an embodiment of the expansion body according to the present invention. FIG. 13: is sectional drawing in CC cross section of one Embodiment of the expansion body based on this invention. FIG. 14 is a cross-sectional view of one embodiment of the expansion body according to the present invention. FIG. 15 is a side view of an embodiment of the expansion body according to the present invention. FIG. 16: is sectional drawing in the FF cross section of one Embodiment of the expansion body which concerns on this invention. FIG. 17 is a side view of an embodiment of the expansion body according to the present invention. FIG. 18 is a schematic view of a bending plate used for evaluation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Bending plate 12 Polyethylene pipe 13 Linear part 14 Bending part 15 Outer diameter of polyethylene pipe 16 Inner diameter of polyethylene pipe 101 Expansion body 102 Straight pipe section 103 Stress concentration element 201 Expansion body 202 Straight pipe section 203 Stress concentration element 203A Stress concentration element 203B Stress Concentrating Element 203C Stress Concentrating Element 203D Stress Concentrating Element 203E Stress Concentrating Element 204A Parallel Part 204B Parallel Part 301 Expansion Body 302 Straight Pipe Part 303 Stress Concentration Element 303A Stress Concentration Element 303B Stress Concentration Element 401 Expansion Body 402 Straight Pipe Part 403 Stress Concentration Element 403A Stress concentration element 403B Stress concentration element 403C Stress concentration element 403D Stress concentration element 404A Parallel portion 404B Parallel portion 501 Expansion body 502 Straight pipe portion 503 Stress concentration element 503A Stress concentration element 03C Stress concentration element 503E Stress concentration element 504A Parallel portion 504B Parallel portion 601 Expansion body 602 Straight tube portion 603 Stress concentration element 605 Protection member 701 Expansion body 702 Straight tube portion 703 Stress concentration element 703A Stress concentration element 703C Stress concentration element 703E Stress concentration element 703E Element 801 Expansion body 802 Straight pipe portion 803 Stress concentration element 803A Stress concentration element 803C Stress concentration element 803E Stress concentration element 806 Support member

Claims (13)

A catheter expansion body having a straight tube portion and a joint portion to be joined to the catheter shaft,
The catheter expansion body comprises:
A plurality of stress concentration elements arranged on the outer peripheral surface of the expansion body along the longitudinal direction of the straight pipe section, which moves in a direction away from the longitudinal central axis of the straight pipe section with expansion of the expansion body, With
The catheter expansion body, wherein at least some of the stress concentration elements included in the plurality of stress concentration elements are distributed over the central axis direction of the straight pipe portion. The at least some stress concentrating elements further include:
The catheter expansion body according to claim 1, wherein the catheter expansion body is disposed at different circumferential positions with respect to a central axis of the straight pipe portion. The at least some stress concentrating elements further include:
The catheter expansion body according to claim 2, wherein at least a part of the stress concentration element is arranged so as to be parallel to a circumferential direction of the straight pipe portion. The length of at least one parallel portion of the stress concentration elements juxtaposed in the circumferential direction of the straight pipe portion is ½ or less of the longitudinal length of the at least one stress concentration element in parallel;
The catheter expansion body according to claim 3. The at least some stress concentrating elements further include:
There is only one other stress concentration element parallel to the circumferential direction of the straight pipe portion with respect to at least a part of the stress concentration element;
The expansion body for catheters of Claim 3 or 4 characterized by these. The at least some stress concentrating elements further include:
While at least a part of the stress concentration element existing at one end of the straight pipe portion has only one other stress concentration element parallel to the circumferential direction of the straight pipe portion, There are two or more other stress concentration elements juxtaposed in the circumferential direction of the straight pipe portion with respect to at least a part of the stress concentration elements existing at the other end,
The expansion body for catheters in any one of Claims 3-5 characterized by these. Each stress concentration element included in the plurality of stress concentration elements is:
The circumferential positions are different from each other with respect to the central axis of the straight pipe portion, and are arranged at positions spaced apart from circumferential portion lengths at regular intervals.
The expansion body for catheters in any one of Claims 2-6 characterized by these. The longitudinal lengths of the stress concentration elements included in the plurality of stress concentration elements are the same;
The expansion body for catheters in any one of Claims 1-7 characterized by these.   The catheter expansion body according to any one of claims 1 to 8, wherein a cross-sectional shape of at least a part of the stress concentration element is circular.   The catheter expansion body according to any one of claims 1 to 8, wherein a cross-sectional shape of at least a part of the stress concentration element is a tapered shape that gradually decreases in a direction away from the straight pipe portion. .   The expansion body for a catheter according to any one of claims 1 to 9, wherein at least a part of the distal end portion in the circumferential direction of the straight pipe portion of the stress concentration element is a blade.   The catheter expansion body according to claim 11, further comprising a protection member that protects the blade. The catheter which has the said shaft with which the said catheter expansion body in any one of Claims 1-12 was joined.

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