JP3754055B2 - Instrument for treatment of stenosis in body cavity - Google Patents

Description

  The present invention is for placing a self-expandable stent (self-expandable stent) in a stenosis or occlusion formed in a living body such as a blood vessel, bile duct, trachea, esophagus, urethra, gastrointestinal tract, or other organs. The present invention relates to a device for treating a stenosis in a body cavity.

Conventionally, a stenosis in a body cavity that secures a lumen or body cavity space by placing a stent in a stenosis or occlusion in a body lumen or body lumen such as a blood vessel, bile duct, esophagus, trachea, urethra, digestive tract, or other organ An orthopedic device has been proposed.
As the stent constituting the therapeutic device, there are a balloon expandable stent and a self-expandable stent depending on the function and the indwelling method.

The balloon expandable stent does not have an expansion function, and in order to place the stent at a target site, for example, after inserting the stent to the target site, the balloon is positioned in the stent and the balloon is expanded. The stent is expanded (plastically deformed) by an expansion force, and is fixed in close contact with the inner surface of the target site.
This type of stent requires the above-described stent expansion operation, but it can be placed by directly attaching the stent to a deflated balloon, so that there is not much problem with placement. However, since the stent itself has no expansion force, the diameter is reduced with time due to the pressure of the blood vessel and the like, and there is a high possibility that restenosis will occur.

In contrast, the self-expandable stent has a contraction and expansion function. In order to place the stent in the target site, the stress applied to maintain the contracted state is removed after the stent is inserted into the target site in the contracted state. For example, the stent is contracted and stored in a sheath having an outer diameter smaller than the inner diameter of the target site, and after the distal end of the sheath reaches the target site, the stent is pushed out of the sheath. The extruded stent is released from the sheath to release the stress load, and restores and expands to the shape before contraction. Thereby, it adheres and fixes to the inner surface of the target part.
Since this type of stent has an expansion force, the stent itself does not need to be expanded like a balloon expandable stent, and there is no problem that the diameter is gradually reduced due to the pressure of the blood vessel and restenosis is caused. .

As a device for treating a stenosis in a body cavity for placing such a self-expandable stent at a target site, for example, a self-expanding built-in artificial organ disclosed in Japanese Patent Laid-Open No. 6-197985 (Patent Document 1) is used. The apparatus 70 is disclosed. As shown in FIG. 7, the device 70 is accommodated in the outer tube body 71, the inner tube body 73 having the small diameter portion 72, and the outer tube body 71 in the vicinity of the outside of the small diameter portion 72. And a stent 74.
US Pat. No. 4,735,152 (Patent Document 2) discloses a technique in which a stent is covered with a double-structured membrane, the membrane is peeled off while pressing between the membranes at about 5 atm, and the stent is released.
Further, US Pat. No. 5,026,377 (Patent Document 3) discloses a stent in which a stent is housed between an inner catheter and an outer catheter, and an anti-slip member is attached to the inner catheter or anti-slip processing is performed.
Further, JP-A-6-210004 (Patent Document 4) discloses an inner catheter formed by connecting a tip, a connector piece, and a catheter, and an outer catheter, and a portion formed between the outer catheter and the connector piece. In which a stent is housed.
JP-A-6-197985 USP 4735152 USP 5026377 JP-A-6-210004

However, in the apparatus of Japanese Patent Laid-Open No. 6-197985 (Patent Document 1), a step is formed on the rear end side of the distal end portion 73 a of the inner tube body 73, so that the inner tube body 73 is expanded after the stent 74 is expanded. When pulling out, the rear end surface of the distal end portion 73a of the inner tube body may be caught by the stent 74, shifting the placement position of the stent 74, or making it difficult or impossible to remove the inner tube body 73. Further, the apparatus of USP 4735152 (Patent Document 2) has a complicated structure and peels the membrane while applying pressure, so two operators are required for the stent placement operation. Furthermore, the device of USP 50263377 (Patent Document 3) or Japanese Patent Laid-Open No. 6-210004 (Patent Document 4) requires attachment of a non-slip member, anti-slip processing, or connection processing of a tip, a connector piece, and a catheter. The production was not easy.
Therefore, the object of the present invention is to prevent the extraction of the tube body from the possibility that the rear end surface of the tube body is caught on the stent, the placement position of the stent is shifted, and the tube body is difficult or impossible to remove. An object of the present invention is to provide a treatment device for treating a stenosis in a body cavity that can easily place a panda stent in an accurate position and can be easily manufactured with a simple structure.

What solves the above-described problem is a sheath, a tube body that includes a distal end portion that is inserted through the sheath and protrudes from the distal end of the sheath, and a stent storage portion that is provided proximal to the distal end portion; A device for treating a stenosis in a body cavity comprising a stent accommodated between the sheath and the stent accommodating portion of the tube body, wherein the stent is formed in a substantially cylindrical shape and is inserted in a central axis direction when inserted into a living body. It is compressed and expanded outward during indwelling and restored to its original shape, and is held in the sheath in a compressed state in the direction of the central axis. The vicinity of the distal end of the portion is formed in a tapered portion that gradually increases in diameter toward the distal end side, and further, one or more holes are provided near the distal end of the sheath, and the distal end of the sheath Said A body cavity stricture therapeutic instrument is in contact with the outer surface of the cube body. In particular, the vicinity of the distal end of the stent storage portion is formed in a tapered portion that gradually increases in diameter toward the distal end side (in other words, gradually decreases in diameter toward the proximal end side), so the tube body is removed. In doing so, it is possible to prevent the stent from being caught by the distal end portion of the tube body and the indwelling position to shift, and the tube body from being difficult or impossible to remove.

  The distal end portion of the tube body is preferably formed in a tapered portion that gradually decreases in diameter toward the distal end side. By forming the tip portion in this manner, expansion of the constricted portion and insertion resistance to the constricted portion can be reduced. In addition, a stent locking portion is provided on the proximal end side of the stent housing portion of the tube body. This makes it easier to release the stent than the sheath.

The distal end of the sheath is preferably curved inward so that the distal end surface is in contact with the outer surface of the tube body. As a result, since the distal end surface of the sheath is not exposed, there is no step at the distal end, insertion resistance to the narrowed portion is reduced, and damage to the inner wall of the blood vessel by the distal end surface can be prevented. Further, the distal end of the sheath may be located outside the tapered portion of the stent housing portion, and the outer diameter of the sheath may be formed substantially the same as the diameter of the maximum diameter portion of the tube body. .

  A hub having a valve body that is slidable and liquid-tightly holds the tube body is provided at a proximal end portion of the sheath, and the hub preferably has a liquid port. With these configurations, the inside of the sheath can be primed by flowing physiological saline or contrast medium into the sheath from the liquid port. In addition, the contrast agent is injected into the sheath from the liquid port, the contrast agent is allowed to flow out from the hole at the tip, and the operation can be advanced while confirming the state of the stenosis with an X-ray monitor, so that the stent is positioned accurately. Can be detained.

  The intra-body-cavity stenosis treatment instrument preferably has a fixing means for releasably fixing the sheath to the tube body. Since the relative position of the tube body and the sheath can be fixed until the target site is reached, the operation can be made easy and safe. Moreover, it is preferable that the diameter of the stent accommodating portion of the tube body is formed such that the rigidity of the entire device for treating a stenosis in the body cavity is substantially uniform. Thereby, the insertion into the bent body cavity becomes easier.

  In the body cavity stenosis treatment instrument of the present invention, the vicinity of the distal end of the stent housing portion is formed as a tapered portion that gradually increases in diameter toward the distal end side. For this reason, when the tube body is removed, it is possible to prevent the stent from being caught by the distal end portion of the tube body and the placement position from being displaced or the tube body from becoming unremovable.

A device for treating a stenosis in a body cavity of the present invention will be described with reference to an embodiment shown in the drawings.
FIG. 1 is a front view of an embodiment of the intraluminal stenosis treatment instrument of the present invention, and FIG. 2 is a cross-sectional view of the vicinity of the distal end of the intraluminal stricture treatment apparatus shown in FIG. 3 is a partially omitted enlarged cross-sectional view in the vicinity of the proximal end portion of the intraluminal stenosis treatment device shown in FIG. 1, and FIGS. 4 and 5 are used for the intraluminal stenosis treatment device of the present invention, respectively. It is a perspective view of an example of the stent for indwelling in a body cavity.
The intra-body-cavity stenosis treatment instrument 1 according to this embodiment is provided with a hollow sheath 3, a distal end portion 4 that is inserted through the sheath 3 and protrudes from the distal end of the sheath 3, and a proximal end side from the distal end portion 4. A device for treating a stenosis in a body cavity comprising a stent 2 housed between a tube body 6 provided with a stent housing portion 5 and a stent housing narrow diameter portion 5 of the sheath 3 and the tube body 6. The stent 2 is formed in a substantially cylindrical shape, is compressed in the central axis direction when inserted into a living body, expands outward when it is placed in the living body, and restores the original shape, and is compressed in the central axis direction. In this state, it is held in the sheath 3. The vicinity of the distal end of the stent housing small-diameter portion 5 of the tube body 6 is formed in a tapered portion 6a that gradually increases in diameter toward the distal end side.
Each configuration will be described below.

  As shown in FIG. 1, the tube body 6 has a distal end portion 4 protruding from the distal end of the sheath 3. The distal end portion 4 is a portion that is inserted while expanding the skin or tissue, and is preferably formed in a tapered portion that gradually decreases in diameter toward the distal end side. By forming in this way, it is possible to reduce expansion of the constriction and insertion resistance into the constriction.

  The outer diameter of the most distal end portion 4a of the distal end portion 4 is preferably 0.5 mm to 1.8 mm, and in this embodiment is formed to 1.2 mm. Moreover, it is preferable that the outer diameter of the maximum diameter part 4b of the front-end | tip part 4 is 0.8-4.0 mm, and is formed in this Example at 3.1 mm. Further, the length of the tip side taper portion is preferably 5.0 to 30.0 mm. In this embodiment, the tip side taper portion is formed to have a long taper of 15.0 mm, and the insertion resistance to the narrowed portion of the tip portion is less. It is supposed to be.

  As shown in FIG. 2, a stent accommodating small-diameter portion 5 for accommodating a body cavity placement stent 2 described later is provided on the proximal end side of the distal end portion 4 of the tube body 6. The vicinity of the distal end of the stent accommodating thin diameter portion 5 is formed into a tapered portion 6a that gradually decreases in diameter toward the proximal end side (in other words, gradually increases in diameter toward the distal end side). That is, it is formed on a gently sloping surface without a step so that the diameter between the tip of the narrow diameter portion 5 and the maximum outer diameter portion of the non-thin diameter portion (tip portion) gradually increases toward the tip side. Has been. Since it has such a taper part 6a, when extracting a tube body, it can prevent that a stent is hooked on the front-end | tip part of a tube body, and an indwelling position shifts, or it becomes difficult or impossible to remove a tube body. .

The outer diameter of the stent accommodating thin diameter portion 5 is preferably 0.7 to 3.5 mm, and in this embodiment, it is formed to 2.2 mm. Note that the outer diameter of the stent accommodating small diameter portion 5 is selected in consideration of the thickness of the stent 2 to be used. The length of the tapered portion 6a provided in the vicinity of the distal end of the stent accommodating small diameter portion 5 is preferably 2 to 10 mm, and in this embodiment is formed to be about 8 mm. Various methods for producing the stent accommodating small-diameter portion 5 are conceivable. For example, any of mechanical polishing, chemical polishing, electrical polishing, and the like may be used, but mechanical polishing is preferable, and centerless polishing is particularly preferable. Is more preferable because it is easy to work.
In addition, it is preferable that the diameter of the small diameter part 5 for stent accommodation of the tube body 6 is formed in the magnitude | size which becomes substantially uniform with the rigidity of the whole instrument 1 for treatment of a constriction in a body cavity. Thereby, the insertion into the bent body cavity becomes easier. In this embodiment, the outer diameter of the tube body 6c on the proximal end side with respect to the stent locking portion 8 to be described later is set to 2.5 mm so that the rigidity of the entire body stenosis treatment instrument 1 becomes substantially uniform. Is formed. Since the outer diameter of the tube body 6c on the proximal end side from the stent locking portion 8 changes depending on the rigidity of the stent to be used, the outer diameter of the tube body 6c is appropriately determined in consideration of the rigidity of the stent (particularly, the rigidity stored in the sheath). select.

  A stent locking portion 8 is provided on the proximal end side of the stent housing thin diameter portion 5 of the tube body 6. As a result, when the sheath 3 moves toward the rear end of the sheath 3, the stent 2 can be abutted, and the stent 2 can be discharged from the distal end opening of the sheath 3 and can be left in the stenosis. In other words, the stent locking portion 8 is for locking the movement of the stent 2 accompanying the movement of the sheath 3 in the rear end direction.

  As shown in FIG. 2, the stent locking portion 8 of this embodiment is formed by an annular protrusion (annular rib) having an outer diameter smaller than the inner diameter of the sheath 3 and larger than the inner diameter of the contracted stent 2. For this reason, the stent locking portion 8 does not become an obstacle to the movement of the sheath 3 in the axial direction, and since it is annular, the stent 2 is reliably brought into contact with the stent 2 when the sheath 3 moves forward. Can be released. In addition, since the front end surface 8a of the stent locking portion 8 that contacts the rear end of the stent 2 of this embodiment extends in the direction perpendicular to the axial direction, it contacts the stent 2 more reliably.

  The outer diameter of the stent locking portion 8 is preferably 0.8 to 4.0 mm. In this embodiment, the outer diameter is 3.1 mm. In addition, although the stent latching | locking part 8 has such a preferable annular protrusion part, what is necessary is just what can latch the movement of the stent 2 accompanying the movement to the rear-end direction of the sheath 3, for example, a tube One or a plurality of protrusions may be provided integrally with the body 6 or as separate members. Moreover, when forming the stent latching | locking part 8 by another member, you may form by X-ray contrast material (X-ray impermeable material). Thereby, the position of the stent can be accurately grasped under X-ray contrast, and the procedure becomes easier. In addition, when a portion of the stent is covered, in order to confirm the position where the covering portion is provided, the stent accommodating small diameter portion at a position corresponding to both ends of the portion where the covering portion is provided is provided. X-ray contrast material can also be wrapped or implanted. As the X-ray opaque material, for example, a wire can be wound and fixed with gold, platinum, platinum-iridium alloy, silver, stainless steel, platinum, or an alloy thereof, or a pipe can be suitably used.

  As shown in FIGS. 2 and 3, a lumen 6 b for inserting a guide wire over the entire length is provided inside the tube body 6. The diameter of the lumen 6b varies depending on the guide wire used, but is preferably about 0.4 to 1.3 mm. In this embodiment, the diameter is 1.2 mm. The total length of the tube body 6 is preferably about 350 to 850 mm. In this embodiment, the total length is 420 mm.

  The tube body 6 penetrates through the sheath 3 and protrudes from the rear end opening of the sheath. As shown in FIG. 3, a hub 7 is fixed to the base end portion of the tube body 6, and the hub 7 is provided with a guide wire insertion portion 7 a that communicates with the lumen 6 b of the tube body 6 and has an open rear end. It has been.

  The material for forming the tube body 6 is preferably a material having hardness and flexibility. For example, fluorine-based polymers such as polyethylene, polypropylene, nylon, polyethylene terephthalate, and ETFE can be suitably used. The outer surface of the tube body 6 may be coated with a resin having biocompatibility, particularly antithrombogenicity. As the antithrombogenic material, for example, polyhydroxyethyl methacrylate, a copolymer of hydroxyethyl methacrylate and styrene (for example, HEMA-St-HEMA block copolymer), or the like can be preferably used.

  Furthermore, it is preferable that the outer surface of the part which protrudes from the sheath 3 among the tube bodies 6 has lubricity. For this purpose, for example, coated with a hydrophilic polymer such as poly (2-hydroxyethyl methacrylate), polyhydroxyethyl acrylate, hydroxypropyl cellulose, methyl vinyl ether maleic anhydride copolymer, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, or It may be fixed. Moreover, you may coat or fix the said thing to the whole outer surface of the tube body 6. FIG. Furthermore, in order to improve the slidability with the guide wire, the above may be coated or fixed on the inner surface of the tube body 6.

  As the material for forming the hub 7, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be suitably used.

  The stent 2 used in this intraluminal stenosis treatment instrument 1 is a so-called self-expandable stent. Specifically, it has a shape as shown in FIG. 4 (showing a state expanded and restored to its original shape). The stent 2 of this embodiment has a cylindrical frame body 20, an opening 24 partitioned (enclosed) by frames 26 a and 26 b constituting the cylindrical frame body 20, and a notch 25 partitioned by the frame 26 a. The frame body 20 has both end portions 23a and 23b.

  A synthetic resin or a metal is used as a material for forming the stent. As the synthetic resin, those having a certain degree of hardness and elasticity are used, and a biocompatible synthetic resin is preferable. Specifically, polyolefin (for example, polyethylene, polypropylene), polyester (for example, polyethylene terephthalate), fluororesin (for example, PTFE, ETFE), or polylactic acid, polyglycolic acid, or polylactic acid that is a bioabsorbable material For example, a copolymer of polyglycolic acid. In addition, a metal having biocompatibility is preferable, and examples thereof include stainless steel, tantalum, and nickel titanium alloy. In particular, a super elastic metal is preferable. It is preferable that the stent 2 is integrally formed without forming a sudden change point of physical properties as a whole. For example, a stent is prepared by preparing a metal pipe having an outer diameter suitable for an in-vivo site to be placed, and partially removing the side surface of the metal pipe by cutting, chemical etching, or the like, so that a plurality of notches are formed on the side surface. It is created by forming a part or a plurality of openings.

  Since the stent 2 has the notch 25 at the end of the frame body 20, the ends 23a and 23b of the stent 2 can be easily deformed. In particular, the end can be partially deformed, and the indwelling blood vessel is deformed. Good response to time. Moreover, since the edge part 23 is formed of the edge part of the some flame | frame 26a, it is hard to be crushed and has sufficient intensity | strength. Further, an opening 24 surrounded by the frames 26a and 26b is formed between both ends, and the opening 24 is easily deformed by deformation of the frame 26a. For this reason, the stent 2 can be easily deformed at the center (the center of the frame body 20). Note that the cutouts and openings are not limited to the shape and number shown in the figure, and 3 to 10 cutouts and about 3 to 10 openings are suitable.

  The frame body 20 has an outer diameter of 2.0 to 30 mm, preferably 2.5 to 20 mm, an inner diameter of 1.4 to 29 mm, preferably 1.6 to 29.4 mm, and has a length of 10 It is -150mm, More preferably, it is 15-100mm.

  The shape of the stent is not limited to the stent shown in FIG. 4, for example, a trapezoidal notch is formed at both ends, and a plurality of hexagonal openings are formed in a honeycomb at the center. Further, a rectangular cutout may be formed at both ends, and a plurality of rectangular openings (having twice the length of the cutout) may be formed at the center. Furthermore, the shape of the stent 2 is not limited to the above-described shape as long as it can be reduced in diameter when inserted and can be expanded (restored) when released into the body. For example, a coil shape, a cylindrical shape, a roll shape, a deformed tubular shape, a higher order coil shape, a leaf spring coil shape, a cage or a mesh shape may be used.

  As the superelastic metal forming the stent, a superelastic alloy is preferably used. The superelastic alloy here is generally called a shape memory alloy, and exhibits superelasticity at least at a living body temperature (around 37 ° C.). Particularly preferably, a TiNi alloy of 49 to 53 atomic% Ni, a Cu—Zn alloy of 38.5 to 41.5 wt% Zn, a Cu—Zn—X alloy of 1 to 10 wt% X (X = Be, Si, Sn, Al, Ga), a super elastic metal body such as a 36-38 atomic% Al Ni-Al alloy is preferably used. The TiNi alloy is particularly preferable. Further, a Ti—Ni—X alloy in which a part of the Ti—Ni alloy is substituted with 0.01 to 10.0% X (X = Co, Fe, Mn, Cr, V, Al, Nb, W, B, etc.) Or a Ti—Ni—X alloy (X = Cu, Pb, Zr) in which a part of the Ti—Ni alloy is substituted by 0.01 to 30.0% atoms, and the cold work rate Alternatively, mechanical properties can be appropriately changed by selecting conditions for the final heat treatment. Further, the mechanical properties can be appropriately changed by selecting the cold work rate and / or the final heat treatment conditions using the Ti—Ni—X alloy.

The buckling strength (yield stress during loading) of the superelastic alloy used is 5 to 20 kg / mm ² (22 ° C.), more preferably 8 to 150 kg / mm ^2. Restoring stress (yield stress during unloading) ) Is 3 to 180 kg / mm ² (22 ° C.), more preferably 5 to 130 kg / mm ² . Superelasticity here means that even if it is deformed (bending, pulling, compressing) to a region where normal metal is plastically deformed at the operating temperature, it is restored to its original shape without requiring heating after the deformation is released. Means that.

  In addition, the stent constituting the intraluminal stenosis treatment instrument of the present invention may be as shown in FIG. The stent 42 according to this embodiment includes a stent body 42a having a substantially cylindrical shape, a thermoplastic resin layer covering the stent body 42a, a side surface of the stent body 42a, and a thermoplastic resin layer. And a cylindrical cover 43 fixed to the head. The difference between the stent 42a and the stent 2 described above is that the side wall (outer periphery, inner periphery, outer periphery surface, or inner peripheral surface) of the stent body 42a is encapsulated (sealed) by the cylindrical cover 43. For this reason, since the communication part (hole) formed in the stent side wall such as the opening and the notch of the stent body 42a is sealed by the cover, it is possible to prevent the living tissue from entering the stent from the outside. Further, the cylindrical cover 43 is heat-sealed to a thermoplastic resin, so that the cylindrical cover 43 is not peeled off from the stent body 42a, and both are not separated during and after placement of the stent. .

  The stents 2 and 42 formed as described above are accommodated between the inner wall surface near the distal end of the sheath 3 and the stent accommodating small diameter portion 5 of the tube body 6 in a contracted state, and contact the inner surface of the sheath. Is retained. Since the stent 2 has an expansion force as described above, the stent 2 is in a state of being stuck by pressing the inner wall surface of the sheath 3 in the radial direction.

  The sheath 3 is a tubular body as shown in FIG. 1, and has a front end opening and a rear end opening (not shown) at the front end and the rear end. The distal end opening functions as a discharge port of the stent 2 when the stent 2 is placed in a stenosis in the body cavity. When the stent 2 is detached from the distal end opening, the stress load is released and the stent 2 is expanded and restored to its original shape.

  As shown in FIG. 2, the distal end of the sheath 3 is curved inward so that the distal end surface 31 is in contact (preferably in close contact) with the outer surface of the tube body 6 to form a curved portion 32. This is so-called R processing, whereby the distal end surface of the sheath does not form a step and is not exposed.

  As shown in FIG. 3, a sheath hub 34 including a valve body 33 that is slidable and liquid-tight is provided at the proximal end portion of the sheath 3. The sheath hub 34 has a liquid port 35. Further, one or more holes 36 are provided in the vicinity of the distal end of the sheath 3. With these configurations, the inside of the sheath 3 can be primed by flowing physiological saline or an angiographic contrast agent into the sheath 3 from the liquid port 35. Further, since the contrast agent is injected into the sheath 3 from the liquid port 35 and the contrast agent is allowed to flow out from the hole 36 at the tip, the operation can be advanced while confirming the state of the stenosis with an X-ray monitor. It can be placed in the correct position. More specifically, as shown in FIG. 1, the device 1 for treating a stenosis in a body cavity of this embodiment has a three-way cock 37 attached to the liquid port 35, and a syringe (not shown) is attached to the three-way cock 37. )) And injecting physiological saline or contrast medium.

  The outer diameter of the sheath 3 is preferably about 1.0 to 5.2 mm. In this embodiment, the outer diameter is 3.8 mm. The inner diameter of the sheath 3 is preferably about 0.9 to 4.5 mm. In this embodiment, the inner diameter is 3.4 mm. The length of the sheath 3 is preferably about 250 to 750 mm. In this embodiment, the length is 320 mm.

The material for forming the sheath 3 is preferably a thermoplastic elastomer in consideration of physical properties required for the sheath (flexibility, hardness, strength, kink resistance, stretchability), nylon-based (for example, polyamide elastomer), urethane It is appropriately selected from a system (for example, polyurethane elastomer), a polyester system (for example, polyethylene terephthalate elastomer), and an olefin system (for example, polyethylene elastomer, polypropylene elastomer), and more preferably a urethane system.
Furthermore, it is preferable that the outer surface of the sheath 3 is subjected to a treatment for exhibiting lubricity. Examples of such treatment include hydrophilic polymers such as poly (2-hydroxyethyl methacrylate), polyhydroxyethyl acrylate, hydroxypropyl cellulose, methyl vinyl ether maleic anhydride copolymer, polyethylene glycol, polyacrylamide, and polyvinylpyrrolidone. Examples of the method include coating or fixing. Moreover, in order to improve the slidability with the tube body 6 on the inner surface of the sheath 3, the above-described one may be coated or fixed.

  As a material for forming the sheath hub 34, a thermoplastic resin such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be suitably used.

  Furthermore, the intraluminal stenosis treatment instrument 1 of this embodiment has a fixing means 50 for releasably fixing the sheath 3 to the tube body 6 as shown in FIG. Thereby, since the relative position of the tube body and the sheath can be fixed until the target site is reached, the operation can be made easy and safe.

  Specifically, the fixing means 50 (fixing mechanism, locking mechanism) is integrally formed with a sheath mounting portion 51, a tube body mounting portion 52, and a connecting portion 53 that connects both, and the sheath mounting portion 51. Has a sheath fixing recess 51 a having a shape corresponding to the outer shape of the sheath hub 34, and the tube body mounting portion 52 has a shape corresponding to the outer shape of the enlarged diameter portion 7 b near the tip of the hub 7. It has a tube body fixing recess 52a. Then, the fixing means 50 moves the sheath 3 and the tube body 6 downward from the upper side of FIG. 1 with the side where the sheath fixing recess 51a and the tube body fixing recess 52a are provided downward. When attached and removed, it is formed so that it can be easily detached by moving upward.

Next, another embodiment of the intraluminal stenosis treatment instrument of the present invention shown in FIG. 8 will be described.
The difference between the embodiment 60 and the above-described intra-body-cavity stenosis treatment instrument 1 is that the distal end 63a of the sheath 3 is positioned outside the tapered portion 6a of the stent accommodating thin diameter portion 5, and the outer diameter of the sheath 3 is determined. However, it is only the point currently formed substantially the same as the diameter of the largest diameter part 64 of the tube body 6, and others are the same. Thereby, the piercing resistance can be further reduced and the operation is facilitated.

Next, a method of using the device for treating a stenosis in a body cavity of the present invention will be described with reference to the drawings.
First, as shown in FIG. 1, in a state where the relative position between the sheath 3 and the tube body 6 is fixed by the fixing means 50, the fixing means 50 or the sheath 3 is grasped, and a guide wire (indwelled in advance) ( (Not shown) is inserted into the lumen 6b of the tube body 6, and the intraluminal stenosis treatment instrument 1 of the present invention is inserted into the body cavity (for example, blood vessel) along the guide wire. This insertion is performed while allowing the contrast medium injected from the fluid port 35 to flow out of the hole 36 and confirming its position by X-ray contrast, and positioning the stent 2 in the target stenosis.
Next, the fixing means 50 is removed and the sheath 3 is moved to the proximal side in the axial direction. At this time, since the rear end surface of the stent 2 is brought into contact with and locked with the distal end surface of the stent locking portion 8, the stent 2 is discharged from the distal end opening of the sheath 3 as the sheath 3 moves as shown in FIG. Is done. By this discharge, the stent 2 is placed in the stenosis.
Thereafter, the procedure is completed by moving the tube body 6 toward the proximal end side in the axial direction and removing it from the stent 2 and the body cavity. When the tube body 6 is removed, the intraluminal stenosis treatment instrument 1 of the present invention is gradually reduced in diameter near the distal end side of the stent accommodating thin diameter portion 5 of the tube body 6 toward the proximal end side. Since the taper portion 6a is formed, the stent 2 is not caught by the distal end portion of the tube body 6 so that the placement position is not shifted and the tube body 6 cannot be removed.

FIG. 1 is a front view of an embodiment of a device for treating a stenosis in a body cavity according to the present invention. 2 is a cross-sectional view of the vicinity of the distal end portion of the intra-body-cavity stenosis treatment instrument shown in FIG. FIG. 3 is a partially omitted enlarged cross-sectional view in the vicinity of the proximal end portion of the intraluminal stenosis treatment instrument shown in FIG. FIG. 4 is a perspective view of an example of a stent for placement in a body cavity used in the device for treating a stenosis in a body cavity of the present invention. FIG. 5 is a perspective view of another example of a stent for placement in a body cavity used in the device for treating a stenosis in a body cavity of the present invention. FIG. 6 is a front view for explaining the operation of the device for treating a stenosis in a body cavity of the present invention. FIG. 7 is an explanatory diagram for explaining the operation of the device for treating a stenosis in a body cavity of the present invention. FIG. 8 is a cross-sectional view showing another embodiment of the device for treating a stenosis in a body cavity of the present invention. FIG. 9 is a front view of a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intrabody cavity constriction part treatment instrument 2 Intrabody cavity placement stent 3 Sheath 3a Sheath inner surface 4 Tip part 5 Stent accommodation thin diameter part 6 Tube body 6a Taper part 6b Lumen 7 Hub 7a Guide wire insertion part 7b Widening part 8 Stent Locking portion 8a Tip surface 36 hole

Claims (7)

A sheath including a sheath, a distal end portion that is inserted through the sheath and protrudes from the distal end of the sheath, and a stent storage portion provided on a proximal end side from the distal end portion; and the sheath and the stent of the tube body A device for treating a stenosis in a body cavity comprising a stent stored between storage units, wherein the stent is formed in a substantially cylindrical shape, compressed in the direction of the central axis when inserted into a living body, and externally placed when placed in a living body. And is restored in its original shape and held in the sheath in a state compressed in the direction of the central axis, and the vicinity of the distal end of the stent storage portion Further, one or more holes are provided in the vicinity of the distal end of the sheath, and the distal end of the sheath is formed on the outer surface of the tube body. In contact Vivo stenosis treatment device, characterized in that that. The device for treating a stenosis in a body cavity according to claim 1, wherein the distal end portion of the tube body includes a tapered portion that gradually decreases in diameter toward the distal end side. 3. The intra-body-cavity stenosis treatment instrument according to claim 1, wherein a stent locking portion is provided on a proximal end of the tube housing portion of the tube body or on a proximal end side of the stent housing portion. The device for treating a stenosis in a body cavity according to any one of claims 1 to 3, wherein the distal end of the sheath is curved inward so that the distal end surface is in contact with the outer surface of the tube body. The hub of the valve | bulb body provided with the valve body which can hold | maintain the said tube body is slidable and liquid-tightly is provided in the base end part of the said sheath, This hub has a liquid port. The device for treating a stenosis in a body cavity according to any one of the above. The stent storage portion has a cylindrical portion without a step, and further, the vicinity of the distal end of the stent storage portion is continuous with the cylindrical portion without the step, toward the distal end, and at the maximum diameter portion of the distal end portion The device for treating a stenosis in a body cavity according to any one of claims 1 to 5, wherein the device is formed in a tapered portion that gradually increases in diameter without any step extending to the end. The intra-body-cavity stenosis-treating device according to any one of claims 1 to 6, further comprising a fixing unit that releasably fixes the sheath to the tube body.

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