JP2012239758A - Stent delivery catheter and method for manufacturing pusher tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stent delivery catheter having a softened inner shaft besides, suitably designing a gap between an outer shaft and the inner shaft, and accordingly improving a stent indwelling performance.SOLUTION: The inner shaft includes a guide wire guiding tube 12 and a pusher tube 11 into which the guide wire guiding tube 12 is inserted, and only the resin pusher tube 11 includes a slit.

Description

  The present invention relates to a stent delivery catheter and a pusher tube manufacturing method.

  A stent is a medical device for treating various diseases caused by stenosis or occlusion of blood vessels or other in vivo lumens. Specifically, the stent is placed at the lesion site to expand the stenosis or occlusion site (lesion site) and maintain an expanded lumen size.

  Examples of the stent include two types (types). One is a balloon-expandable type that is expanded by a balloon in a balloon catheter, and the other is a self-expandable type that expands itself by removing a member that holds the stent to be expanded from the outside. .

  The self-expanding stent delivery catheter that carries the self-expanding stent has a cylindrical structure having a distal end and a proximal end, and an outer shaft that holds the self-expanding stent in the lumen, An inner shaft inserted into the cavity.

  More specifically, the outer shaft and the inner shaft are independent of each other, and both shafts are arranged coaxially by inserting the inner shaft into the inner cavity of the outer shaft. Then, the outer shaft slides with respect to the inner shaft, so that the self-expanding stent attached in a reduced diameter state near the tip of the lumen in the outer shaft comes into contact with a part of the inner shaft, It is pushed out from the lumen of the shaft and percutaneously placed at the treatment site in the body lumen of the patient (Patent Document 1, etc.).

International Publication No. 2006/13396

  A problem of the stent delivery catheter as described above is safe and accurate placement of the stent. If the rigidity of the inner shaft that pushes out the stent from the lumen of the outer shaft is large, the stent can be accurately placed. However, if the outer diameter of the inner shaft is small, the gap between the outer shaft and the inner shaft becomes large, and the inner shaft is bent in the outer shaft regardless of the rigidity of the inner shaft, making accurate stent placement difficult.

  For example, according to the description in Patent Document 1, a metal tube is used as a part of the inner shaft so that the inner shaft has axial rigidity. Furthermore, the flexibility is ensured by continuously forming a spiral slit in the metal tube. However, in metal tubes that require microfabrication, such as spiral slits, the thickness of the metal tube must be reduced, and the gap between the outer shaft and the inner shaft becomes large, impairing stent placement performance. There is a fear.

  An object of the present invention is to provide a stent delivery catheter in which the gap between the outer shaft and the inner shaft can be appropriately designed and the inner shaft can be made flexible, resulting in improved stent placement performance. .

  The stent delivery catheter includes an outer shaft and an inner shaft that is inserted into the outer shaft. In the stent delivery catheter, the inner shaft includes a guide wire guide tube and a pusher tube into which the guide wire guide tube is inserted, and only the resin pusher tube includes a slit.

  Further, when a plurality of slits are formed side by side in the direction of extension of the pusher tube, it is preferable that there are a plurality of types of slit insertion directions.

  Also, one of the slit insertion directions is defined as a first insertion direction, a slit inserted in that direction is defined as a first slit, another direction relative to the first insertion direction is defined as a second insertion direction, and a slit inserted in that direction is defined as When the second slit is used, it is preferable that the first slit and the second slit are alternately arranged in at least a part of the group of the plurality of slits arranged in parallel.

  Further, it is preferable that a fifth slit which is a slit to be inserted is formed between the first slit and the second slit arranged in parallel in a fifth insertion direction different from the first insertion direction and the second insertion direction.

  In addition, in the first slit, the fifth slit, and the second slit that are arranged in parallel, when the insertion direction of these slits is projected onto one cross section in the extension direction of the pusher tube, the first insertion direction, the fifth slit, The insertion direction and the second insertion direction are preferably grasped radially.

  Further, when a plurality of fifth slits are formed side by side in the pusher tube extension direction, one of the fifth insertion directions of the slits is defined as a third insertion direction, and the fifth slit inserted in that direction is defined as the third slit. If the slit and another direction with respect to the third insertion direction are the fourth insertion direction and the fifth slit inserted in that direction is the fourth slit, at least a part of the group of the plurality of fifth slits arranged in parallel is the third slit. And the fourth slits are preferably arranged alternately.

  Further, in the first slit, the third slit, the second slit, and the fourth slit, which are arranged in parallel, when the insertion direction of the slit is projected onto one cross section in the extension direction of the pusher tube, It is preferable that the insertion direction, the third insertion direction, the second insertion direction, and the fourth insertion direction are grasped radially.

  In addition, it is preferable that the first insertion direction and the second insertion direction have a forward / reverse direction relationship.

  Moreover, it is preferable that the first insertion direction, the fifth insertion direction, and the second insertion direction have a radial arrangement relationship at intervals of 120 ° in the cross section.

  In addition, it is preferable that the first insertion direction, the third insertion direction, the second insertion direction, and the fourth insertion direction have a radial arrangement relationship at intervals of 90 ° in the cross section.

  The inner shaft preferably includes a pusher wire connected to the guide wire guide tube.

  Moreover, it is preferable that the guide wire guide tube and the pusher tube are integrally formed.

  Moreover, it is preferable that at least a part of the outer shaft is formed of a composite tube of metal and resin.

  The stent delivery catheter is preferably an over-the-wire type or a rapid exchange type.

  The stent is preferably a self-expanding stent or a self-expanding stent graft.

  In addition, the manufacturing method of the pusher tube included in the stent delivery catheter includes a preparation step of preparing a resin tube as a main body of the pusher tube, an insertion step of inserting a slit into the resin tube, and heating for applying heat to the resin tube. And a process.

  In the insertion step, it is preferable to insert the slits from at least two directions.

  Moreover, it is preferable that a heating process is performed in the state which applied the tension | tensile_strength to the resin tube.

  According to the stent delivery catheter of the present invention, the gap between the outer shaft and the inner shaft can be appropriately designed, and the inner shaft can be made flexible. As a result, the stent placement performance can be enhanced.

These are explanatory drawings of a stent delivery catheter. These are explanatory drawings of the outer shaft contained in a stent delivery catheter. These are explanatory drawings of the inner shaft contained in a stent delivery catheter. FIG. 3 is a perspective view of a stent. FIG. 2 is a cross-sectional view showing a stent or the like attached to an outer shaft (a cross-sectional view taken along the line A-A ′ in FIG. 1). FIG. 3 is a cross-sectional view showing a pusher tube and the like in the outer shaft (a cross-sectional view taken along line B-B ′ in FIG. 1). FIG. 2 is a cross-sectional view showing a pusher tube and the like in the outer shaft (a cross-sectional view taken along line C-C ′ in FIG. 1). FIG. 3 is a cross-sectional view showing a pusher tube and the like in the outer shaft (a cross-sectional view taken along line D-D ′ in FIG. 1). These are explanatory drawings of a stent delivery catheter. These are explanatory drawings of a stent delivery catheter. FIG. 11 is a cross-sectional view showing a pusher tube and the like in the outer shaft (a cross-sectional view taken along line E-E ′ in FIG. 10). FIG. 11 is a cross-sectional view showing a pusher tube and the like in the outer shaft (a cross-sectional view taken along line F-F ′ in FIG. 10). FIG. 12 is a cross-sectional view showing a pusher tube and the like in the outer shaft (a cross-sectional view taken along line G-G ′ in FIG. 10). FIG. 11 is a cross-sectional view showing a pusher tube and the like in the outer shaft (a cross-sectional view taken along line H-H ′ in FIG. 10). These are explanatory drawings which show the insertion direction of a slit. These are explanatory drawings which show the insertion direction of a slit. These are explanatory drawings of a stent delivery catheter. FIG. 19 is a cross-sectional view showing a pusher tube and the like in the outer shaft (a cross-sectional view taken along line J-J ′ in FIG. 18). These are explanatory drawings of a stent delivery catheter. These are explanatory drawings of the inner shaft contained in a stent delivery catheter.

[Embodiment 1]
The following describes one embodiment with reference to the drawings. For convenience, hatching, member codes, and the like may be omitted, but in such a case, other drawings are referred to. Conversely, for convenience, hatching may be used even if it is not a sectional view. Moreover, the dimension of the various members in drawing may be adjusted so that it may be easy to see for convenience.

  Further, on both sides of the stent delivery catheter, the side that accommodates the stent is referred to as the distal side, and the opposite side to the distal side is referred to as the proximal side (note that the distal end is the distal end and the proximal side) Is also referred to as the proximal end). A delivery catheter equipped with a stent may be referred to as a stent delivery catheter, or the delivery catheter itself may be referred to as a stent delivery catheter.

  FIG. 1 shows a stent delivery catheter 49 fitted with a self-expanding stent 39. FIG. 2 shows the outer shaft 29 included in the self-expanding stent delivery catheter 49 of FIG. FIG. 3 shows the inner shaft 19 included in the self-expanding stent delivery catheter 49 of FIG. 1 (the inner shaft 19 is accommodated in the lumen 29L of the outer shaft 29). 4 shows an example of a self-expanding stent 39, and FIG. 5 is a cross-sectional view showing the stent 39 attached to the outer shaft 29 (note that FIG. 5 is a view taken along the line AA ′ in FIG. It is a sectional view).

  The self-expanding stent 39 shown in FIG. 4 is formed by continuously arranging an annular substantially corrugated component 31 along one direction. The substantially corrugated component 31 is formed by connecting extending struts 32. The stent 39 is accommodated at the tip of the lumen 29L of the outer shaft 29. When a self-expanding stent is covered with a resin tube, the stent 39 is called a stent graft.

  The outer shaft 29 shown in FIG. 2 holds the self-expanding stent 39 in a reduced diameter state on the distal side of its own lumen 29L. Further, the outer shaft 29 must have a strength that can withstand the force generated when the stent 39 is placed. Therefore, the outer shaft 29 is formed of a material having flexibility and kink resistance that does not break during blood vessel following. For example, the outer shaft 29 (for example, a tube constituting a part of the distal side; a distal tube) preferably has a tensile strength of 20 N or more and a kink bending radius of 15 mm or less as a physical property example.

  In order to ensure such physical properties, the outer shaft 29 is preferably a multilayer tube (a multilayer tube including a metal and a resin) including the inner layer 21, the reinforcing layer 22, and the outer layer 23.

  The inner layer 21 is preferably formed of a low friction material. This is because, when the inner layer 21 is made of a low friction material, when the stent 39 housed in the lumen 29L of the outer shaft 29 is left in the body, the outer shaft 29 generates a load as much as possible without causing a load. This is for sliding with respect to the shaft 19. In addition, as a low friction material, a fluorine resin or a high density polyethylene is mentioned, for example.

  The reinforcing layer 22 is preferably formed of a metallic strand or a resin strand so as to have flexibility or kink resistance. Examples of these strands include, for example, stainless steel strands or Nitinol strands. The reinforcing layer 22 has a blade structure or a coil structure.

  In the case where the outer shaft 29 is a multilayer tube, in order to fix the reinforcing layer 22 to the inner layer 21 in the step of manufacturing the multilayer tube, the distal end and the proximal end of the reinforcing layer 22 having a blade structure or a coil structure are provided. For example, a ring-shaped braided marker (not shown) made of Pt: Ir is arranged.

  The outer layer 23 is preferably formed of a material that can be welded or adhered when the outer shaft 29 is manufactured. Examples of such a material include polyamide elastomer, nylon, or polyethylene.

  A hub 27 is connected to the proximal end of the outer shaft 29, and a Y-type connector or the like is connected through the hub 27. As a result, the contrast agent or the like is released to the distal end of the stent delivery catheter 49 via the Y-type connector.

  The inner shaft 19 shown in FIG. 3 has a role of relatively pushing out the stent 39 by sliding the outer shaft 29 holding the stent 39 on the distal side. Therefore, the inner shaft 19 has a strength that accurately pushes out the stent 39 without bending and does not bend in the axial direction of pushing out.

  The inner shaft 19 includes a guide wire guide tube 12 for passing a guide wire (not shown), a distal tip 13 for preventing blood vessel damage, a stent pressing member 14 for pushing out a stent 39, a pusher tube 11, and an inner operation portion 17. .

  The guide wire guide tube 12 is a tube having a lumen 19L of a size that allows a guide wire (not shown) to pass therethrough. Examples of the material of the guide wire guide tube 12 include polyimide, polyamide-based elastomer, nylon, polyethylene, and polyetheretherketone. Further, the guide wire guide tube 12 may be a single layer tube or a multilayer tube.

  The distal tip 13 is disposed at the distal end (distal end) of the guide wire guide tube 12. The tip 13 has a shape that does not include an edge in order to prevent blood vessel damage. Further, a reduced diameter stent 39 in the outer shaft 29 is disposed between the distal tip 13 and the stent compression member 14 (see FIG. 1).

  The stent compression member 14 is, for example, a metal tube, and is disposed in the vicinity of the guide wire guide tube 12 that is deviated from the distal tip 13 by a predetermined distance {Note that the stent compression member 14 and the guide wire guide tube 12 are connected ( Fixing) is not particularly limited such as adhesion, pressure bonding, or welding}. The stent compression member 14 contacts the proximal end (proximal end) of the stent 39 that moves in accordance with the proximal slide of the outer shaft 29 and has a role of pushing out as an action point. In addition, as for the metal used as a stent compression member, the alloy of stainless steel or Pt and Ir is mentioned, for example.

  The pusher tube 11 is, for example, a cylindrical resin tube, is disposed on the proximal side with the stent compression member 14 as a boundary, and covers the surface (outside) of the guide wire guide tube 12. More specifically, the proximal end of the stent compression member 14 and the distal end of the pusher tube 11 are arranged to contact each other (note that the pusher tube 11 and the guide wire guide tube 12 can be connected by, for example, bonding, Welding or crimping). Examples of the material for forming the pusher tube 11 include polyamide-based elastomer, polyimide, polyethylene terephthalate, nylon, polyethylene, and polyetheretherketone.

  The pusher tube 11 is inserted with slits ST in the radial direction of the pusher tube 11 (which can be said to be orthogonal to the extension direction of the pusher tube 11), and the plurality of slits ST are arranged in the extension direction of the pusher tube 11. line up. The slit ST will be described in detail later.

  The inner operation portion 17 is an operation portion that covers the guide wire guide tube 12 and is connected to the proximal end of the pusher tube 11, and includes, for example, a metal hollow tube. In addition, when the stent 39 is indwelling, it is desirable that the inner operation portion 17 has a size that can easily support the stent delivery catheter by the operator's hand.

  Here, the pusher tube 11 shown in FIG. 1, FIG. 3, and FIG. 6 to FIG. 8 will be described in detail (Note that FIG. 6 is a cross-sectional view taken along line BB ′ in FIG. 1, and FIG. 1 is a cross-sectional view taken along the line CC ′ of FIG. 1, and FIG. 8 is a cross-sectional view taken along the line DD ′ of FIG.

  As shown in FIG. 1, the inner shaft 19 includes a guide wire guide tube 12 and a pusher tube 11 into which the guide wire guide tube 12 is inserted, but only the resin pusher tube 11 has the slit ST. Including.

  Thus, when the pusher tube 11 in which the slit ST is engraved covers the guide wire guide tube 12, the pusher tube 11 has a strength that does not bend with respect to the strength of the guide wire guide tube 12 (the axial direction of pushing out the stent 39). ), The flexibility of the inner shaft 19 does not decrease due to the slit ST.

  In addition, the pusher tube 11 including the slit ST is not metallic but made of resin. In general, a metal pusher tube having a slit has to be relatively thin in order to process the slit or the like, and the surface of the pusher tube 11 and the inner wall of the lumen 29L in the outer shaft 29 , And the placement accuracy of the stent 39 of the stent delivery catheter 49 is likely to be lowered.

  However, in the case of the resin-made pusher tube 11 having slits, the distance between the surface of the pusher tube 11 and the inner wall of the lumen 29L of the outer shaft 29 can be appropriately designed, so that the placement accuracy of the stent 39 of the stent delivery catheter 49 is improved. Get higher.

  In addition, since the metal pusher tube having a slit is easily distorted and easily plastically deformed, it is extremely dangerous when the stent delivery catheter is caught in the blood vessel, but the stent delivery includes the resin pusher tube 11 having the slit. Such a dangerous situation is unlikely to occur in the catheter 49.

  That is, according to the stent delivery catheter 49 as described above, the gap between the outer shaft 29 and the inner shaft 19 can be appropriately designed, and the inner shaft 19 can be made flexible. As a result, the placement performance of the stent 39 is improved. It is done.

  A plurality of slits ST are formed side by side in the extending direction of the pusher tube 11. Furthermore, the slit ST is inserted into the pusher tube 11 in a direction intersecting with the extending direction of the pusher tube 11 (for example, the slit ST is inserted along the radial direction of the pusher tube 11). There are a plurality of insertion directions of the slits ST. Therefore, the flexibility of the inner shaft 19 is ensured in various directions.

  For example, as shown in FIG. 6, one insertion direction in a cross section (for example, an orthogonal cross section) with respect to the extending direction of the pusher tube 11 is defined as a first insertion direction D1. A plurality of slits ST (first slits ST1) inserted in the first insertion direction D1 are arranged in the extension direction of the pusher tube 11 as shown in FIG.

  Further, as shown in FIG. 7, a plurality of slits ST inserted in the opposite direction, which is a different direction from the first insertion direction D1, are arranged in the extending direction of the pusher tube 11, as shown in FIG. (The insertion direction opposite to the first insertion direction D1 is referred to as the second insertion direction D2, and the slit ST inserted in the second insertion direction D2 is referred to as the second slit ST2.) .

  The first slit ST1 and the second slit ST2 do not exist in the same cross section, and are formed in a shifted manner in the extension direction of the pusher tube 11 (essentially as shown in FIGS. 1 and 8). A portion without the slit ST is generated between the first slit ST1 and the second slit ST2. For example, in the pusher tube 11, the first slits ST1 and the second slits ST2 are alternately arranged in at least a part of a group of the plurality of slits ST arranged in parallel (the intervals between all the slits ST are constant). Or irregular).

  A stent delivery catheter 49 including an inner shaft 19 having such a pusher tube 11 and an outer shaft 29 in which the inner shaft 19 is coaxially arranged is a self-expandable stent 39 as shown in FIG. In place. More specifically, only the outer shaft 29 is slid to the proximal side while the inner shaft 19 remains stationary, so that the inner shaft 19 relatively pushes out the stent 39 and the stent 39 held by the outer shaft 29 is released. Thus, the stent delivery catheter 49 is used by an unfamiliar medical staff because the stent 39 is released only by sliding the outer shaft 29, because the stent 39 is released. But simple and easy to operate).

  In addition, since the pusher tube 11 having the slit ST is included in the inner shaft 19, a gap between the outer shaft 29 and the inner shaft 19 is appropriately set, and the stent 39 is accurately placed without the inner shaft 19 being bent. Be made. Further, the pusher tube 11 causes the inner shaft 19 to secure axial rigidity. On the other hand, the slit ST of the pusher tube 11 ensures flexibility in the radial direction with respect to the stent delivery catheter 49. As a result, the stent delivery catheter 49 can place the stent 39 safely and accurately.

  The insertion length of the slit ST may be a length from the surface of the pusher tube 11 to the central axis of the pusher tube 11 as shown in FIGS. Good. Further, as long as the pusher tube 11 is not cut by the slit ST, the insertion length of the slit ST may be longer than the length from the surface of the pusher tube 11 to the central axis of the pusher tube 11 (preferably, the insertion length). The length from the surface of the pusher tube 11 to the central axis of the pusher tube 11 is good, with half the circumferential length of the pusher tube 11 as a cut surface).

  Further, the inner shaft 19 having the slit ST along the radial direction of the pusher tube 11 is, for example, an inner shaft in the patient's blood vessel as compared with an inner shaft in which a spiral slit is formed along the extending direction of the pusher tube. When a situation where the wire is pulled occurs, the structure is less likely to be distorted and less likely to be plastically deformed.

  Note that the slit ST inserted into the pusher tube 11 is not limited to the first slit ST1 and the second slit ST2. For example, a stent delivery catheter 49 including the pusher tube 11 as shown in FIGS. 10 shows the stent delivery catheter 49, FIG. 11 is a cross-sectional view taken along line EE ′ of FIG. 10, and FIG. 12 is a cross-sectional view taken along line FF ′ of FIG. 13 is a cross-sectional view taken along the line GG ′ in FIG. 10, and FIG. 14 is a cross-sectional view taken along the line HH ′ in FIG. 10, and the points from E to H are aligned in the direction of extension of the pusher tube. Yes.

  According to these drawings, the first insertion direction D1 shown in FIG. 11 and the second insertion direction D2 shown in FIG. [5th insertion direction], a slit [fifth slit] ST is formed (note that the first insertion direction D1 is 0 o'clock direction and the second insertion direction D2 is 6 o'clock direction using the dial of the watch) Sometimes called).

  The different direction includes, for example, a direction (third insertion direction D3) inclined 45 ° clockwise toward the distal side with respect to the first insertion direction D1, as shown in FIG. Moreover, as shown in FIG. 14, the direction (4th insertion direction D4) which inclined 45 degrees clockwise toward the distal side with respect to the 2nd insertion direction D2 is mentioned as an example of another direction.

  That is, the third insertion direction D3 and the fourth insertion direction D4 in different directions are different from each other and have a forward / reverse direction relationship. In other words, the third insertion direction D3 is the 3 o'clock direction and the fourth insertion direction. It can be said that D4 is oriented in the 9 o'clock direction.

  Then, in at least a part of the group of the plurality of slits ST in different directions arranged in parallel, the slit ST (third slit ST3) inserted in the third insertion direction D3 and the fourth insertion inserted in the fourth insertion direction D4. The slits ST4 are alternately arranged.

  In addition, in the first slit ST1, the third slit ST3, the second slit ST2, and the fourth slit ST4 arranged in parallel, the insertion direction of these slits ST is as shown in FIG. 15 in the extension direction of the pusher tube 11. When projected onto one cross section CS, the first insertion direction D1, the third insertion direction D3, the second insertion direction D2, and the fourth insertion direction D4 are grasped radially.

  More specifically, the first insertion direction D1, the third insertion direction D3, the second insertion direction D2, and the fourth insertion direction D4 are in a radial arrangement relationship at 90 ° intervals in the cross section CS.

  With such a pusher tube 11, slits ST from multiple directions are inserted around the pusher tube 11, and the flexibility of the inner shaft 19 is further secured in various directions (note that all The intervals between the slits ST may be constant or irregular).

  The relationship of the radial arrangement in the insertion direction in the cross section CS is not limited to the relationship of the equal arrangement in the four insertion directions as shown in FIG. 15. For example, as shown in FIG. The relationship may be an even arrangement in the insertion direction.

  For example, one of the slit insertion directions is the insertion direction Da [first insertion direction], the slit inserted in that direction is the slit STa [first slit], and another direction with respect to the insertion direction Da is the insertion direction Db [second insertion direction]. The insertion direction] is a slit STb [second slit], and the insertion direction Da and the insertion direction Dc [fifth] are different from the insertion direction Da and the insertion direction Db. The slit inserted in the “insertion direction” is defined as a slit STc [fifth slit].

  Then, in the slit STa, the slit STc, and the slit STb that are sequentially arranged in parallel, when the insertion direction of these slits is projected onto one cross section CS in the extension direction of the pusher tube 11, as shown in FIG. The direction Da, the insertion direction Dc, and the insertion direction Db may be grasped radially.

  In this way, the insertion direction Da, the insertion direction Dc, and the insertion direction Db are in a radial arrangement relationship at an interval of 120 ° in the cross-section CS (note that the intervals between all the slits ST) Can be constant or irregular). And even if it is such a pusher tube 11, the slit ST from many directions will be inserted in the circumference | surroundings of the pusher tube 11, and the softness | flexibility of the inner shaft 19 is further ensured in various directions.

  In addition, the method of inserting the slit ST into the pusher tube 11 (that is, the manufacturing method of the pusher tube 11 including the slit ST) is as follows.

  The slit ST is formed using a razor. More specifically, a razor is used to cut a resin tube (a tube on which the pusher tube 11 is based). The interval between the cuts (that is, the interval between the slits ST) may be constant or irregular.

  The cutting direction is the radial direction of the resin tube. The cross section of the resin tube can be compared to a clock face. For example, the direction of 0 o'clock, 6 o'clock (2 directions), 0, 3, 6, 9 o'clock (4 directions), 0 o'clock, 4 o'clock , 8 o'clock direction (3 directions), it is preferable to cut the pusher tube 11 in order from the distal side to the proximal side.

  In the process of forming the cuts in the resin tube, it is preferable that the resin tube is heat-treated in a state where a weight or the like is attached to the distal end and the proximal end and tension is generated.

  Further, the guide wire guide tube 19 and the pusher tube 11 may be integrally formed. In the case of an integral tube including the guide wire guide tube 19 and the pusher tube 11 as described above, a partially thick resin tube is used for forming the slit ST, and a cut is formed. In the process, it is preferable that the resin tube is heat-treated in a state where a weight or the like is attached to the distal end and the proximal end and tension is generated.

  Further, an integrally molded tube including the guide wire guide tube 19 and the pusher tube 11 may be formed by injection molding using a mold that generates the slit ST.

[Embodiment 2]
A second embodiment will be described. In addition, the same code | symbol is attached about the member which has the same function as the member used in Embodiment 1, and the various description of the member is abbreviate | omitted.

  In the first embodiment, as shown in FIG. 1, the inner shaft 19 includes the pusher tube 11 that covers the guide wire guide tube 12, but may further include another member. For example, as shown in FIGS. 17 and 18 (a cross-sectional view taken along line J-J ′ in FIG. 17), the pusher wire 16 may be included in the inner shaft 19.

  More specifically, the pusher wire 16 is housed in the gap between the pusher tube 11 and the guide wire guide tube 12, and the vicinity of the proximal end of the stent compression member 14 and the vicinity of the distal end of the pusher wire 16 are aligned. It arrange | positions so that it may overlap with the surface of the guide wire guide tube 12 (namely, the proximal end of the stent compression member 14 and the distal end of the pusher tube 11 contact | connect). The pusher tube 11 covers the proximal guide wire guide tube 12 and the push wire 16 with the stent compression member 14 as a boundary.

  Note that the pusher wire 16 is made of, for example, a metal such as stainless steel or nickel titanium.

  Even in the stent delivery catheter 49 including such an inner shaft 19, when the pusher tube 11 described in the first embodiment covers the guide wire guide tube 12, the pusher tube 11 is connected to the guide wire guide tube 12. While the strength is reinforced, the flexibility of the inner shaft 19 does not decrease due to the slit ST. As a result, the effects described in the first embodiment are achieved.

[Embodiment 3]
A third embodiment will be described. In addition, about the member which has the same function as the member used in Embodiment 1 * 2, the same code | symbol is attached, and various description of the member is abbreviate | omitted.

  In the first and second embodiments, as shown in FIGS. 1 and 17, the over-the-wire stent delivery catheter 49 in which the guide shaft lumen 19L is included in the entire length of the inner shaft 19 is taken as an example. However, it is not limited to this.

  For example, as shown in FIG. 19, a high-speed exchange type (rapid exchange type) stent delivery catheter 49 in which a guide wire lumen is formed in a part of the entire length of the shaft tube may be used.

  In such a fast exchange type stent delivery catheter 49, the outer shaft 29 is connected to the distal tube 24 disposed on the distal side, the intermediate tube 25 connected to the distal tube 24, and the two-hole type intermediate tube 25. (In the vicinity of the joint between the distal tube 24 and the intermediate tube 25, the tubes 24 and 25 are mixed together, and this portion is referred to as a transition portion MX).

  The inner shaft 19 allows the guide wire guide tube 12 to be inserted into one hole of the intermediate tube 25 having two holes by the outer shaft 29, while the pusher wire 16 is inserted into the other hole.

  Even in the stent delivery catheter 49 including such an inner shaft 19, when the pusher tube 11 described in the first embodiment covers the guide wire guide tube 12, the pusher tube 11 is connected to the guide wire guide tube 12. While the strength is reinforced, the flexibility of the inner shaft 19 does not decrease due to the slit ST. As a result, the effects described in the first embodiment are achieved.

  Further, the guide wire guide tube 19 and the pusher tube 11 may be integrally formed. In such a case, for example, by using a mold, as shown in FIG. 20, the pusher tube and the guide wire guide tube may be integrally injection-molded. (Note that the integrally molded tube 10 has a hole 16L into which the push wire 16 can be inserted, and the push wire 16 is inserted into the hole 16L and then bonded.

  Examples of the stent delivery catheter 49 will be described below, but the present invention is not limited to this.

Example 1
The self-expanding stent 39 is manufactured as follows. That is, a nickel-titanium alloy pipe with φ (outer diameter) of 2.2 mm is laser-cut, expanded to φ8.0 mm and subjected to heat treatment, so that the expanded diameter is 8 mm and the axial length (full length) is 45 mm The stent 39 is manufactured.

  The outer shaft 29 (outer diameter 2.08 mm, inner diameter 1.78 mm) is manufactured as follows. First, a PTFE-coated wire having a thickness of 40 μm (core material: φ1.78 mm annealed copper wire, manufactured by Nissei Electric Co., Ltd.), a SUS304 strand having a width of 100 μm and a thickness of 25 μm, a Pt: Ir ring having a thickness of 50 μm and an outer diameter of 2.05 mm Marker (contrast marker, Pt: Ir = 9: 1 / Accelent), outer layer tube made of nylon 12 with outer diameter of 2.23 mm and inner diameter of 2.05 mm (Daiamide / Daicel Dexer), and heat shrinkable tube (RNF -100-3 / 32, made of cross-linked polyethylene / Tyco Electronics).

  Then, 16 strands are arranged at equal intervals on the PTFE covered wire, and bladed at intervals of 4 mm. The ring marker is coaxially arranged outside the braided covered wire and further fixed.

  Next, the end of the SUS wire is cut with a YAG laser, and the sharp portion of the end is dissolved by electropolishing. An 850 mm outer layer tube is then placed outside the 950 mm bladed coated wire, and the heat-shrinkable tube covers the bladed coated wire. Then, only the outer layer tube is disposed outside the 10 mm ring marker.

  Next, the core material of the PTFE-coated wire is removed, and the coated wire is cut so that the effective length is 830 mm. Thereby, the outer shaft 29 is completed (the hub 27 is urethane-bonded to the proximal end of the outer shaft 29).

  The inner shaft 19 is manufactured as follows. First, guide wire guide tube 12 (outer diameter 0.73 mm, inner diameter 0.53 mm, length 260 mm, polyimide, manufactured by Micro-Lumen), pusher wire 16 (φ0.50 mm, length 1000 mm, manufactured by Yokowo), resin tube (Outer diameter 1.60 mm, inner diameter 1.28 mm, length 700 mm, polyamide elastomer, manufactured by Arkema), stent compression member 14 (outer diameter 1.61 mm, inner diameter 1.25 mm, length 2 mm, manufactured by SUS304), heat shrink A tube (pennit-AWG-20), a core (φ0.52 mm, manufactured by Parylene Coating / Precision Wire), and a two-component mixed urethane adhesive are prepared.

  And from the distal side 20 mm to the proximal end of the resin tube, a notch is made with a razor at intervals of 5 mm. More specifically, while rotating the resin tube by 90 degrees in order to make incisions along the 0, 3, 6 and 9 o'clock directions of the timepiece in the cross section of the resin tube (cross section perpendicular to the full length direction, etc.) Cuts are made in four directions at intervals of 5 mm. The cut resin tube is heat-treated in an oven at 100 ° C. for 1 hour. In addition, the resin tube is heated in a state where tension is applied by a weight of 3 grams, so that the notch creates a gap and becomes a slit. As a result, the pusher tube 11 is completed.

  The pusher wire 16 is arranged at a position 70 mm from the distal end of the guide wire guide tube 12 in parallel with the guide wire guide tube 12 with its distal end in contact. The guide wire guide tube 12 and the pusher wire 16 in contact with each other are inserted into the pusher tube 11. The distal end of the pusher wire 16 and the distal end of the pusher tube 11 are arranged to be aligned. Then, one drop of urethane adhesive is poured into the distal end of the pusher tube 11 and left for 1 hour, and then a range of 10 mm from the distal end of the pusher tube is thermally welded.

  Next, the stent compression member 14 is disposed so as to cover the distal end of the pusher wire 16 and the distal end of the pusher tube 11 and bonded with a urethane adhesive. Thereby, the inner shaft 19 is completed. (In addition, the inner operation portion 17 (outer diameter 1.61 mm, inner diameter 0.51 mm, length 300 mm, made of SUS304) is made of urethane adhesive at the proximal end of the inner shaft 19. Glued}.

  The inner shaft 19 is inserted into the proximal end of the outer shaft 29 from the distal end of the inner shaft 19 and is arranged coaxially. As a result, the stent delivery catheter 49 to which the self-expanding stent 39 shown in FIG. 17 is attached is completed (the stent 39 is mounted in a reduced diameter state in the delivery catheter).

(Comparative Example 1)
The stent delivery catheter of Comparative Example 1 differs from the stent delivery catheter 49 of Example 1 only in that the slit is not included in the pusher tube of the inner shaft, and the rest is the same as the stent delivery catheter 49 of Example 1. It is the same.

(Evaluation 1)
With respect to Example 1 and Comparative Example 1, the following Evaluation 1 was performed. More specifically, the guide wire is sufficiently hydrated, and the delivery catheters of Example 1 and Comparative Example 1 sufficiently contain water in the lumens of the outer shaft and the inner shaft. The guide wire is disposed in the guide wire guide tube of Example 1 and Comparative Example 1. In the 37 ° C. warm water tank, the delivery catheter is placed in a bent state in a lower limb blood vessel model made of a PTFE tube (outer diameter 8 mm, inner diameter 6 mm) while being immersed in warm water. Thereafter, the inner operating portion is fixed by hand, and the hub of the outer shaft is slid proximally, whereby the stent is released. The number of samples is one each.

(Evaluation results)
In Comparative Example 1, the outer shaft could not slide well, the entire delivery catheter was bent, and the stent could not be placed at the target position. In Example 1, the stent could be placed at the target position.

11 Pusher tube ST slit ST1 first slit D1 first insertion direction ST2 second slit D2 second insertion direction ST3 third slit [fifth slit]
D3 Third insertion direction [Fifth insertion direction]
ST4 4th slit [5th slit]
D4 Fourth insertion direction [Fifth insertion direction]
STa slit [first slit]
Da slit insertion direction [first insertion direction]
STb slit [second slit]
Db Slit insertion direction [second insertion direction]
STc slit [5th slit]
Dc Slit insertion direction [Fifth insertion direction]
DESCRIPTION OF SYMBOLS 12 Guide wire guide tube 13 Tip tip 14 Stent compression member 16 Pusher wire 17 Inner operation part 19 Inner shaft 19L Lumen of inner shaft 21 Inner layer 22 Reinforcement layer 23 Outer layer 24 Distal tube 25 Intermediate tube 26 Proximal tube 27 Hub 29 Outer shaft 29L Lumen of outer shaft 39 Stent 49 Stent delivery catheter

Claims (18)

In a stent delivery catheter including an outer shaft and an inner shaft inserted into the outer shaft,
The inner shaft includes a guide wire guide tube and a pusher tube into which the guide wire guide tube is inserted,
A stent delivery catheter in which only the resin pusher tube includes a slit. When the plurality of slits are formed side by side in the direction of extension of the pusher tube,
The stent delivery catheter according to claim 1, wherein there are a plurality of slit insertion directions. One of the slit insertion directions is a first insertion direction, a slit inserted in that direction is a first slit, another direction relative to the first insertion direction is a second insertion direction, and a slit is inserted in that direction. As the second slit,
The stent delivery catheter according to claim 2, wherein the first slit and the second slit are alternately arranged in at least a part of a group of the plurality of slits arranged in parallel.   Between the first slit and the second slit that are arranged in parallel, a fifth slit that is the slit to be inserted is formed in a fifth insertion direction different from the first insertion direction and the second insertion direction. The stent delivery catheter according to claim 3. In the first slit, the fifth slit, and the second slit arranged in parallel, when the projection direction of the slit is projected onto one cross section in the extension direction of the pusher tube,
The stent delivery catheter according to claim 4, wherein the first insertion direction, the fifth insertion direction, and the second insertion direction are grasped radially. When the plurality of fifth slits are formed side by side in the direction of extension of the pusher tube,
One of the fifth insertion directions of the slit is defined as a third insertion direction, the fifth slit inserted in that direction is defined as a third slit, and another direction relative to the third insertion direction is defined as a fourth insertion direction. When the fifth slit to be inserted is the fourth slit,
The stent delivery catheter according to claim 5, wherein the third slit and the fourth slit are alternately arranged in at least a part of the group of the plurality of fifth slits arranged in parallel. In the first slit, the third slit, the second slit, and the fourth slit arranged in parallel, the insertion direction of the slits is projected onto one cross section in the extension direction of the pusher tube. When,
The stent delivery catheter according to claim 6, wherein the first insertion direction, the third insertion direction, the second insertion direction, and the fourth insertion direction are grasped radially.   The stent delivery catheter according to claim 3, wherein the first insertion direction and the second insertion direction are in a forward / reverse direction relationship.   The stent delivery catheter according to claim 5, wherein the first insertion direction, the fifth insertion direction, and the second insertion direction are in a radial arrangement relationship at intervals of 120 ° in the cross section.   The first insertion direction, the third insertion direction, the second insertion direction, and the fourth insertion direction are in a radial arrangement relationship at 90 ° intervals in the cross section. Stent delivery catheter.   The stent delivery catheter according to any one of claims 1 to 10, wherein the inner shaft includes a pusher wire connected to the guide wire guide tube.   The stent delivery catheter according to any one of claims 1 to 11, wherein the guide wire guide tube and the pusher tube are integrally formed.   The stent delivery catheter according to any one of claims 1 to 12, wherein at least a part of the outer shaft is formed of a composite tube of metal and resin.   The stent delivery catheter according to any one of claims 1 to 13, which is an over-the-wire type or a rapid exchange type.   The stent delivery catheter according to any one of claims 1 to 14, wherein the stent is a self-expanding stent or a self-expanding stent graft. In the manufacturing method of the pusher tube included in the stent delivery catheter,
A preparation step of preparing a resin tube as a main body of the pusher tube;
A step of inserting a slit into the resin tube;
A heating step of applying heat to the resin tube;
Of manufacturing a pusher tube containing   The pusher tube manufacturing method according to claim 16, wherein in the inserting step, the slit is inserted from at least two directions. The pusher tube manufacturing method according to claim 16 or 17, wherein the heating step is performed in a state where tension is applied to the resin tube.