JP3586019B2 - Instrument for treating stenosis in body cavity - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is a blood vessel, bile duct, trachea, esophagus, urethra, the stenosis or occlusion formed in the living body such as the digestive tract and other organs, for placing a self-expanding stent (self-expander Bed Rusutento) The present invention relates to a device for treating a stenosis in a body cavity.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a stent is placed in a stenosis or occlusion of a living body lumen or a body cavity such as a blood vessel, a bile duct, an esophagus, a trachea, a urethra, a digestive tract, and other organs to secure a lumen or a body cavity space. Head treatment devices have been proposed.
As the stents constituting the therapeutic device, there are a balloon expandable stent and a self-expandable stent depending on the function and the placement method.
[0003]
The balloon expandable stent has no expansion function in the stent itself.In order to place the stent at the target site, for example, after inserting the stent to the target site, the balloon is positioned inside the stent, the balloon is expanded, and the balloon is expanded. The stent is expanded (plastically deformed) by the expanding force, and is fixed in close contact with the inner surface of the target portion.
This type of stent requires the operation of expanding the stent as described above. However, since the stent can be directly attached to the deflated balloon and placed, there is not much problem with the placement. However, since the stent itself does not have an expanding force, the diameter decreases over time due to pressure of a blood vessel or the like, and there is a high possibility that restenosis occurs.
[0004]
On the other hand, in the self-expandable stent, the stent itself has contraction and expansion functions. In order to place the stent at the target site, the stent is inserted into the target site in a contracted state, and then the stress applied for maintaining the contracted state is removed. For example, the stent is contracted and stored in a sheath having an outer diameter smaller than the inner diameter of the target portion, and after the distal end of the sheath reaches the target portion, the stent is pushed out of the sheath. When the extruded stent is released from the sheath, the stress load is released, and the stent is restored to the shape before contraction and expanded. Thereby, it adheres and fixes to the inner surface of the target part.
This type of stent does not require an expansion work like a balloon expandable stent because the stent itself has an expanding force, and there is no problem that the diameter gradually decreases due to the pressure of the blood vessel and restenosis occurs. .
[0005]
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 device 70 for implanting a self-expanding type built-in artificial organ disclosed in JP-A-6-197985 is disclosed. Have been. As shown in FIG. 7, the device 70 is housed in the outer tube body 71, the inner tube body 73 having the small diameter portion 72, and the inside of the outer tube body 71 near the outside of the small diameter portion 72. And a stent 74.
Further, US Pat. No. 4,735,152 discloses a stent in which a stent is covered with a double-structured membrane, the membrane is peeled off while applying a pressure of about 5 atm between the membranes, and the stent is released.
Further, U.S. Pat. No. 5,026,377 discloses a stent in which a stent is housed between an inner catheter and an outer catheter, and a non-slip member is attached to the inner catheter or a non-slip process is performed.
Further, JP-A-6-210004 discloses that a stent is housed in an inner catheter formed by connecting a distal end tip, a connector piece and a catheter, and an outer catheter and a portion formed between the outer catheter and the connector piece. Things are disclosed.
[0006]
[Problems to be solved by the invention]
However, in the device disclosed in JP-A-6-197985, since a step is formed on the rear end side of the distal end portion 73a of the inner tube body 73, when the inner tube body 73 is removed after the stent 74 is expanded. , the rear end surface of the distal end portion 73a of the inner tube member is caught in the stent 74, or Rashi without the indwelling position of the stent 74, there is a risk that the inner tube member 73 becomes difficult or impossible removal. Further, the device disclosed in US Pat. No. 4,735,152 has a complicated structure, and the membrane is peeled off under pressure, so that two operators are required for the stent placement operation. Furthermore, the apparatus disclosed in US Pat. No. 5,026,377 or Japanese Patent Application Laid-Open No. 6-210004 requires mounting of a non-slip member or non-slip processing, or connection between a distal tip, a connector piece and a catheter, and is not easy to manufacture.
Therefore, an object of the present invention is to remove the tube body, the rear end surface of the tube body distal end portion is caught by the stent, the stent placement position is not shifted, and there is no possibility that the tube body will be difficult or impossible to extract. It is an object of the present invention to provide an instrument for treating a stenosis in a body cavity, which can easily place a pandable stent at an accurate position, has a simple structure, and is easy to manufacture.
[0007]
[Means for Solving the Problems]
What solves the above problem is a tube body including a sheath, a distal end portion that penetrates through the sheath, protrudes from the distal end of the sheath, and a stent storing narrow portion provided on a proximal side from the distal end portion. A device for treating a stenosis in a body cavity comprising a stored stent between the sheath and the small diameter portion for storing the stent of the tube body, wherein the stent is formed in a substantially cylindrical shape and inserted into a living body. The stent is compressed in the central axis direction, expands outward during indwelling in a living body, and restores its original shape, and is held in the sheath in a state of being compressed in the central axis direction, and the stent The storing small-diameter portion has a stepless cylindrical portion, and further, the vicinity of the distal end of the stent storing small-diameter portion is continuous with the stepless cylindrical portion, and heads toward the distal end side and the distal end portion. Extending to the largest diameter part of A body cavity stricture treatment device gradually formed into a tapered portion for diameter expansion without steps. In particular, the vicinity of the distal end of the small diameter portion for storing a stent is formed in a tapered portion that gradually increases in diameter toward the distal end (in other words, gradually decreases in diameter toward the proximal end). When removing the tube, it is possible to prevent the stent from being caught on the distal end portion of the tube body, thereby displacing the indwelling position, and preventing the tube body from being difficult or impossible to remove.
[0008]
It is preferable that the distal end of the tube body is formed in a tapered portion whose diameter gradually decreases toward the distal end side. By forming the distal end portion in this manner, the expansion of the stenosis portion and the insertion resistance to the stenosis portion can be reduced. In addition, a stent locking portion is provided on the proximal end side of the small diameter portion for storing the stent of the tube body. This facilitates release of the stent from the sheath.
[0009]
It is preferable that the distal end of the sheath is curved inward so that the distal end surface is distal to the outer surface of the tube body. Thus, the distal end surface of the sheath is not exposed, there is no difference in level at the tip, the insertion resistance to the stenosis is lowered, or One, it is possible to prevent damage imparted to such a blood vessel inner wall by the distal end surface. Further, the distal end of the sheath is located outside the tapered portion of the thin portion for storing the stent, and the outer diameter of the sheath is formed to be substantially the same as the diameter of the largest diameter portion of the tube body. Is also good.
[0010]
At the base end of the sheath, a hub provided with a valve body slidably and liquid-tightly holding the tube body is provided, and the hub preferably has a liquid port. Further, it is preferable that one or more holes are provided near the distal end of the sheath. With these configurations, a physiological saline solution or a contrast medium can flow into the sheath from the liquid port to prime the sheath. In addition, the contrast agent is injected into the sheath from the liquid port, the contrast agent flows out from the hole at the distal end, and the operation can be performed while confirming the state of the stenosis on the X-ray monitor, so that the stent can be accurately positioned. Can be detained.
[0011]
The instrument for treating a stenosis in a body cavity preferably has fixing means for releasably fixing the sheath to the tube body. Since the relative position between the tube body and the sheath can be fixed until the tube reaches the target portion, the operation can be made easy and safe. Further, it is preferable that the diameter of the stent-containing small-diameter portion of the tube body is set to a size such that the rigidity of the entire instrument for treating a stenosis in a body cavity is substantially uniform. This makes insertion into a bent body cavity easier.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
A device for treating a stenosis in a body cavity according to the present invention will be described with reference to an embodiment shown in the drawings.
FIG. 1 is a front view of one embodiment of a device for treating a stenosis in a body cavity of the present invention, and FIG. 2 is a cross-sectional view near the distal end of the device for treating a stenosis in a body cavity shown in FIG. FIG. 3 is a partially omitted enlarged cross-sectional view showing the vicinity of the base end of the instrument for treating stenosis in a body cavity shown in FIG. 1, and FIGS. 4 and 5 are used for the instrument for treating stenosis in a body cavity of the present invention. It is a perspective view of an example of the stent for indwelling in a body cavity.
[0013]
The instrument 1 for treating stenosis in a body cavity of this embodiment is provided with a hollow sheath 3, a distal end portion 4 that penetrates through the sheath 3, and protrudes from the distal end of the sheath 3, and is provided on the proximal side from the distal end portion 4. This is a device for treating a stenosis in a body cavity, comprising a tube body 6 provided with a small diameter portion 5 for storing a stent and a stent 2 housed between the sheath 3 and the small diameter portion 5 for storing a stent of 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 indwelling in a living body, and restores its original shape, and is compressed in the central axis direction. It is held in the sheath 3 in a state where it is closed. A portion of the tube body 6 near the distal end of the small diameter portion 5 for storing a stent is formed as a tapered portion 6a whose diameter gradually increases toward the distal end side.
Hereinafter, each configuration will be described.
[0014]
As shown in FIG. 1, the distal end portion 4 of the tube body 6 protrudes from the distal end of the sheath 3. The distal end portion 4 is a portion into which the skin or tissue is inserted while expanding, and is preferably formed in a tapered portion whose diameter gradually decreases toward the distal end side. By forming in this manner, it is possible to reduce the expansion resistance of the constricted portion and the insertion resistance into the constricted portion.
[0015]
The outer diameter of the tip 4a of the tip 4 is preferably 0.5 mm to 1.8 mm, and is 1.2 mm in this embodiment. Further, the outer diameter of the maximum diameter portion 4b of the tip portion 4 is preferably 0.8 to 4.0 mm, and is 3.1 mm in this embodiment. Further, the length of the tapered portion on the distal side is preferably 5.0 to 30.0 mm. In this embodiment, the tapered portion is formed to have a long taper of 15.0 mm, and the insertion resistance of the distal portion into the narrow portion is further reduced. It is assumed.
[0016]
As shown in FIG. 2, on the proximal side of the distal end portion 4 of the tube body 6, a stent storing small diameter portion 5 for storing a stent 2 for indwelling in a body cavity described later is provided. In addition, the vicinity of the distal end of the small diameter portion 5 for storing a stent is formed as a tapered portion 6a that gradually decreases in diameter toward the proximal end (in other words, gradually expands in diameter toward the distal end). In other words, a gently sloped surface with no steps is formed so that the diameter between the distal end of the small diameter portion 5 and the maximum outer diameter portion of the non-narrow diameter portion (tip portion) gradually increases toward the distal end side. Have been. Since such a tapered portion 6a is provided, it is possible to prevent the stent from being caught by the distal end portion of the tube body when the tube body is pulled out, thereby displacing the indwelling position, and making it difficult or impossible to pull out the tube body. .
[0017]
The outer diameter of the stent storing small diameter portion 5 is preferably 0.7 to 3.5 mm, and in this embodiment, it is formed to 2.2 mm. The outer diameter of the small diameter portion 5 for storing the stent 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 small-diameter portion 5 for storing a stent is preferably 2 to 10 mm, and is approximately 8 mm in this embodiment. In addition, although various methods of manufacturing the stent containing small diameter portion 5 are conceivable, for example, any of mechanical polishing, chemical polishing, and electric polishing may be used, but mechanical polishing is preferable, and particularly, centerless polishing. However, it is more preferable because of easy work.
In addition, it is preferable that the diameter of the stent containing small diameter portion 5 of the tube body 6 is formed to have a size that is substantially uniform with the rigidity of the entire instrument 1 for treating stenosis in a body cavity. This makes insertion into a bent body cavity easier. In this embodiment, by setting the outer diameter of the tube body 6c on the base end side of the stent locking portion 8 described later to be 2.5 mm, the rigidity of the entire instrument 1 for treating a stenosis in a body cavity becomes substantially uniform. Is formed. Since the outer diameter of the tube body 6c on the base end side of the stent locking portion 8 varies depending on the rigidity of the stent to be used, the rigidity of the stent (particularly, the rigidity in a state of being housed in the sheath) is appropriately considered. select.
[0018]
A stent locking portion 8 is provided on the proximal end side of the small diameter portion 5 for storing the stent of the tube body 6. This allows the stent 2 to come into contact with the stent 2 when moving toward the rear end of the sheath 3, discharge the stent 2 from the distal end opening of the sheath 3, and place the stent 2 in the stenosis. In other words, the stent locking portion 8 locks the movement of the stent 2 accompanying the movement of the sheath 3 toward the rear end.
[0019]
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. Therefore, the stent locking portion 8 does not hinder the movement of the sheath 3 in the axial direction. Further, since the stent locking portion 8 is annular, the stent 3 reliably comes into contact with the stent 2 when the sheath 3 moves forward, so that the stent 2 is securely held. Can be released. In addition, since the distal end face 8a of the stent locking portion 8 which comes into contact with the rear end of the stent 2 of this embodiment extends in the direction perpendicular to the axial direction, it comes into more reliable contact with the stent 2.
[0020]
The outer diameter of the stent locking portion 8 is preferably 0.8 to 4.0 mm, and is 3.1 mm in this embodiment. In addition, the stent locking portion 8 is preferably such an annular projecting portion, but may be any as long as it can lock the movement of the stent 2 accompanying the movement of the sheath 3 toward the rear end. It may be one or more projections provided integrally with the body 6 or as a separate member. When the stent locking portion 8 is formed of a separate member, it may be formed of an X-ray opaque material (X-ray opaque material). Thereby, the position of the stent can be accurately grasped under X-ray contrast, and the procedure becomes easier. Further, when a part of the stent is covered, in order to confirm the position where the covering part is provided, the stent storing small diameter part at a position corresponding to both ends of the part where the covering part is provided. X-ray contrast material can also be wound or embedded. As the X-ray opaque material, for example, a wire can be wound around gold, platinum, a platinum-iridium alloy, silver, stainless steel, platinum, or an alloy thereof, or a pipe can be suitably used.
[0021]
As shown in FIGS. 2 and 3, a lumen 6b for inserting a guide wire is provided inside the tube body 6 over the entire length. The diameter of the lumen 6b varies depending on the guide wire used, but is preferably about 0.4 to 1.3 mm, and in this embodiment, it is 1.2 mm. Further, the total length of the tube body 6 is preferably about 350 to 850 mm, and in this embodiment, it is formed to 420 mm.
[0022]
The tube body 6 penetrates through the sheath 3 and protrudes from a rear end opening of the sheath. As shown in FIG. 3, a hub 7 is fixed to the base end of the tube body 6, and the hub 7 is provided with a guide wire insertion portion 7a communicating with the lumen 6b of the tube body 6 and having an open rear end. Have been.
[0023]
The material for forming the tube body 6 is preferably a material having hardness and flexibility. For example, a fluorine-based polymer 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, especially antithrombotic properties. As the antithrombotic material, for example, polyhydroxyethyl methacrylate, a copolymer of hydroxyethyl methacrylate and styrene (for example, a HEMA-St-HEMA block copolymer) and the like can be suitably used.
[0024]
Further, the outer surface of a portion of the tube body 6 protruding from the sheath 3 preferably has lubricity. For this purpose, for example, a hydrophilic polymer such as poly (2-hydroxyethyl methacrylate), polyhydroxyethyl acrylate, hydroxypropyl cellulose, methyl vinyl ether maleic anhydride copolymer, polyethylene glycol, polyacrylamide, or polyvinylpyrrolidone is coated, or It may be fixed. Moreover, the above-mentioned thing may be coated or fixed on the entire outer surface of the tube body 6. Further, in order to improve the slidability with the guide wire, the above-mentioned thing may be coated or fixed on the inner surface of the tube body 6.
[0025]
As a material for forming the hub 7, a thermoplastic resin such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be suitably used.
[0026]
The stent 2 used in the device 1 for treating a stenosis in a body cavity is a so-called self-expandable stent. Specifically, it has a shape as shown in FIG. 4 (showing a state where it has been expanded and restored to the original shape). The stent 2 of this embodiment has a cylindrical frame body 20, an opening 24 defined (surrounded) by frames 26a and 26b constituting the cylindrical frame body 20, and a cutout 25 defined by the frame 26a. The frame body 20 has both ends 23a and 23b.
[0027]
A synthetic resin or metal is used as a material for forming the stent. As the synthetic resin, a resin having a certain degree of hardness and elasticity is used, and a biocompatible synthetic resin is preferable. Specifically, polyolefin (eg, polyethylene, polypropylene), polyester (eg, polyethylene terephthalate), fluororesin (eg, PTFE, ETFE), or polylactic acid, polyglycolic acid, or polylactic acid that is a bioabsorbable material And copolymers of polyglycolic acid. Further, as the metal, those having biocompatibility are preferable, and examples thereof include stainless steel, tantalum, and nickel titanium alloy. Particularly, a superelastic metal is preferable. It is preferable that the stent 2 is integrally formed without forming a sudden change in physical properties as a whole. For example, a stent is prepared by preparing a metal pipe having an outer diameter adapted to an in-vivo site to be placed, and partially removing the side of the metal pipe by cutting, chemical etching, etc. It is created by forming a part or a plurality of openings.
[0028]
Since the stent 2 has the cutouts 25 at the ends of the frame body 20, the ends 23a and 23b of the stent 2 can be easily deformed. In particular, the ends can be partially deformed, and the deformed blood vessel can be deformed. Good response to time. Further, since the end portion 23 is formed by the end portions of the plurality of frames 26a, it is hard to be crushed and has sufficient strength. An opening 24 surrounded by frames 26a and 26b is formed between both ends, and this opening 24 is easily deformed by deformation of the frame 26a. For this reason, the stent 2 can be easily deformed at its central portion (the central portion of the frame body 20). The shape and the number of the cutouts and the openings are not limited to the illustrated shapes and the numbers. The cutouts are preferably 3 to 10 and the openings are preferably about 3 to 10.
[0029]
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 a length of 10 to 20 mm. To 150 mm, more preferably 15 to 100 mm.
[0030]
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 shape at the center, and Alternatively, a rectangular notch may be formed at both ends, and a plurality of rectangular openings (having twice the length of the notch) may be formed at the center. Furthermore, the shape of the stent 2 is not limited to the above-mentioned shape, as long as the diameter can be reduced when inserted and the diameter can be expanded (restored) when released into the body. For example, it may be a coil, a cylinder, a roll, a deformed tube, a higher coil, a leaf spring coil, a basket or a mesh.
[0031]
A superelastic alloy is suitably used as the superelastic metal forming the stent. The superelastic alloy mentioned here is generally called a shape memory alloy, and exhibits superelasticity at least at a biological 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, and a Cu-Zn-X alloy of 1 to 10 wt% X (X = Be, Si, Superelastic metal bodies such as Sn, Al, Ga) and a 36-38 atomic% Al-Ni-Al alloy are preferably used. Particularly preferred is the above-mentioned TiNi alloy. Also, 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 part of the Ti—Ni alloy is substituted with 0.01 to 30.0% of atoms, and a cold working rate Alternatively, by selecting the conditions of the final heat treatment, the mechanical properties can be appropriately changed. Further, by selecting the cold working ratio and / or the condition of the final heat treatment using the above-mentioned Ti-Ni-X alloy, the mechanical properties can be appropriately changed.
[0032]
The buckling strength (yield stress under load) of the superelastic alloy used is 5 to 20 kg / mm ² (22 ° C.), more preferably 8 to 150 kg / mm ² , and the restoring stress (yield stress at unloading). ) Is 3 to 180 kg / mm ² (22 ° C.), more preferably 5 to 130 kg / mm ² . Superelasticity here means that even if the metal is deformed (bent, tensioned, compressed) to the area where normal metal plastically deforms at the operating temperature, it recovers to almost its original shape without the need for heating after the deformation is released. Means that.
[0033]
Further, the stent constituting the device for treating a stenosis in a body cavity of the present invention may be as shown in FIG. The stent 42 according to this embodiment has a substantially cylindrical stent body 42a that can be reduced in diameter, a thermoplastic resin layer covering the stent body 42a, and a side wall of the stent body 42a. And a cylindrical cover 43 fixed to the cover. The difference between the stent 42a and the above-described stent 2 is that the side wall (outer or inner or outer or inner peripheral surface) of the stent body 42a is covered (closed) by the cylindrical cover 43. For this reason, since the communicating portion (hole) formed in the side wall of the stent such as the opening and the cutout portion of the stent body 42a is closed by the cover, it is possible to prevent the living tissue from entering the stent from the outside. In addition, the tubular cover 43 is thermally fused to the thermoplastic resin, so that the tubular cover 43 does not peel off from the stent body 42a, and the two do not separate during and after placement of the stent. .
[0034]
The stents 2, 42 formed as described above are housed in a contracted state between the inner wall surface near the distal end of the sheath 3 and the stent housing small diameter portion 5 of the tube body 6, and come into contact with the inner surface of the sheath. Is held. Since the stent 2 has an expanding force as described above, the stent 2 presses the inner wall surface of the sheath 3 in the radial direction by itself and is in a state of sticking.
[0035]
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 and rear ends. The distal end opening functions as a discharge port for the stent 2 when the stent 2 is placed in a stenosis in a body cavity. When the stent 2 is detached from the opening at the distal end, the stress load is released, and the stent 2 expands and restores its original shape.
[0036]
As shown in FIG. 2, the distal end of the sheath 3 is curved inward so that the distal end surface 31 contacts (preferably closely contacts) the outer surface of the tube body 6 to form a curved portion 32. This is a so-called R process, whereby the distal end surface of the sheath does not form a step and is not exposed.
[0037]
As shown in FIG. 3, a sheath hub 34 having a valve body 33 slidably and liquid-tightly holding the tube body 6 is provided at a proximal end portion of the sheath 3. Further, the sheath hub 34 has a liquid port 35. Further, one or more holes 36 are provided near the distal end of the sheath 3. With these configurations, it is possible to prime the inside of the sheath 3 by flowing a physiological saline or an angiography agent into the sheath 3 from the liquid port 35. Further, a contrast agent is injected into the inside of the sheath 3 from the liquid port 35, the contrast agent flows out from the hole 36 at the distal end, and the operation can be performed while confirming the state of the stenosis portion with an X-ray monitor. It can be placed in the correct position. More specifically, in the instrument 1 for treating a stenosis in a body cavity of this embodiment, as shown in FIG. 1, a three-way cock 37 is attached to the liquid port 35, and a syringe (not shown) is attached to the three-way cock 37. ) Are connected to inject physiological saline or a contrast medium.
[0038]
The outer diameter of the sheath 3 is preferably about 1.0 to 5.2 mm, and is 3.8 mm in this embodiment. The inner diameter of the sheath 3 is preferably about 0.9 to 4.5 mm, and is 3.4 mm in this embodiment. The length of the sheath 3 is preferably about 250 to 750 mm, and in this embodiment, it is formed to be 320 mm.
[0039]
As a material for forming the sheath 3, a thermoplastic elastomer is preferable in consideration of physical properties (flexibility, hardness, strength, kink resistance, stretchability) required for the sheath, and nylon (eg, polyamide elastomer), urethane The material is appropriately selected from a system (for example, a polyurethane elastomer), a polyester system (for example, a polyethylene terephthalate elastomer), and an olefin system (for example, a polyethylene elastomer or a polypropylene elastomer), and is more preferably a urethane system.
Further, the outer surface of the sheath 3 is preferably subjected to a treatment for providing lubrication. As such a treatment, for example, hydrophilic polymers such as poly (2-hydroxyethyl methacrylate), polyhydroxyethyl acrylate, hydroxypropyl cellulose, methyl vinyl ether maleic anhydride copolymer, polyethylene glycol, polyacrylamide, and polyvinylpyrrolidone are used. Examples of the method include coating or fixing. Moreover, the above-mentioned thing may be coated or fixed on the inner surface of the sheath 3 in order to improve the slidability with the tube body 6.
[0040]
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.
[0041]
Further, as shown in FIG. 3, the instrument 1 for treating a stenosis in a body cavity of this embodiment has a fixing means 50 for releasably fixing the sheath 3 to the tube body 6. Thereby, the relative position between the tube body and the sheath can be fixed until the tube reaches the target portion, so that the operation can be made easy and safe.
[0042]
More 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 for connecting the two. Has a sheath fixing concave portion 51a having a shape corresponding to the outer shape of the sheath hub 34 inside, and the tube body mounting portion 52 has a shape corresponding to the outer shape of the enlarged diameter portion 7b near the distal end of the hub 7 inside. It has a tube body fixing recess 52a. The fixing means 50 is moved downward from above in FIG. 1 with the side on which the sheath fixing concave portion 51a and the tube body fixing concave portion 52a are provided on the lower side. When it is attached and removed, it is formed to be easily detachable by moving it upward.
[0043]
Next, another embodiment of the device for treating a stenosis in a body cavity of the present invention shown in FIG. 8 will be described.
The difference between this embodiment 60 and the above-described instrument 1 for treating a stenosis in a body cavity is that the distal end 63a of the sheath 3 is located outside the tapered portion 6a of the stent containing small diameter portion 5, and the outer diameter of the sheath 3 However, the only difference is that the diameter is formed substantially the same as the diameter of the maximum diameter portion 64 of the tube body 6, and the other points are the same. Thereby, the piercing resistance can be further reduced, and the operation becomes easy.
[0044]
Next, a method for using the instrument 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 ( (Not shown) is inserted into the lumen 6b of the tube body 6, and the instrument 1 for treating stenosis in a body cavity of the present invention is inserted into a body cavity (for example, a blood vessel) along a guide wire. This insertion is performed while the contrast agent injected from the fluid port 35 flows out of the hole 36 and its position is confirmed by X-ray contrast, and the stent 2 is positioned 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 abuts on and is locked by the distal end surface of the stent locking portion 8, the stent 2 is discharged from the distal end opening of the sheath 3 with the movement of the sheath 3 as shown in FIG. Is done. By this ejection, the stent 2 is placed in the stenosis.
Thereafter, the procedure is completed by moving the tube body 6 to 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 instrument 1 for treating a stenosis in a body cavity of the present invention gradually reduces the diameter of the vicinity of the distal end of the small-diameter portion 5 for storing a stent of the tube body 6 toward the base end side. Since the tapered portion 6a is formed, the stent 2 is not caught by the distal end portion of the tube body 6 and the indwelling position is not shifted, and the tube body 6 cannot be removed.
[0045]
【The invention's effect】
An instrument for treating a stenosis in a body cavity of the present invention includes a sheath, a distal end portion that penetrates through the sheath, protrudes from the distal end of the sheath, and a stent-containing thin portion provided on the proximal side from the distal end portion. A tubular body comprising, between the sheath and the small diameter portion for storing the stent of the tubular body, a device for treating a stenosis in a body cavity comprising a stored stent, wherein the stent is formed in a substantially cylindrical shape, It is compressed in the central axis direction during insertion into a living body, expands outward during indwelling in a living body, and restores its original shape, and is held in the sheath while being compressed in the central axis direction. Further, the vicinity of the distal end of the small diameter portion for storing a stent is formed as a tapered portion that gradually increases in diameter toward the distal end side. For this reason, when removing 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 and a tube body cannot be removed.
[Brief description of the drawings]
FIG. 1 is a front view of one embodiment of a device for treating a stenosis in a body cavity of the present invention.
FIG. 2 is a sectional view of the vicinity of the distal end of the instrument for treating stenosis in a body cavity shown in FIG. 1;
FIG. 3 is an enlarged partial cross-sectional view of the vicinity of a base end of the instrument for treating stenosis in a body cavity shown in FIG. 1;
FIG. 4 is a perspective view of an example of a stent for indwelling 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 an indwelling stent 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 instrument for treating a stenosis in a body cavity of the present invention.
FIG. 7 is an explanatory view for explaining the operation of the instrument for treating a stenosis in a body cavity of the present invention.
FIG. 8 is a 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 Instrument for treating stenosis in body cavity 2 Stent for indwelling in body cavity 3 Sheath 3a Inner surface 4 End portion 5 Narrow diameter portion for storing stent 6 Tube body 6a Taper portion 6b Lumen 7 Hub 7a Guide wire insertion portion 7b Enlarged diameter portion 8 Stent Locking part 8a Tip surface

Claims (6)

A tube body including a sheath, a distal end portion that penetrates through the sheath, and protrudes from the distal end of the sheath, and a stent storage thin portion provided on the proximal side from the distal end portion; the sheath and the tube body A device for treating a stenosis in a body cavity, comprising a stent accommodated between the small diameter portions for accommodating a stent, wherein the stent is formed in a substantially cylindrical shape, and is compressed in a central axis direction at the time of insertion into a living body. At the time of indwelling in the body, it expands outward and restores its original shape, and is held in the sheath in a state where it is compressed in the central axis direction, and the stent storing small-diameter portion has a step. A cylindrical portion without the, further, the vicinity of the distal end of the thin portion for storing the stent is continuous with the cylindrical portion without the step , the step toward the distal end and extends to the maximum diameter portion of the distal end. gradually expanded no Vivo stenosis treatment device, characterized in that it is formed in supermarkets portion. The device for treating a stenosis in a body cavity according to claim 1, wherein the distal end of the tube body has a tapered portion whose diameter gradually decreases toward the distal end. The device for treating a stenosis in a body cavity according to claim 1 or 2, wherein a stent engaging portion is provided at a proximal end of the narrow diameter portion for storing the stent of the tube body or at a proximal end side thereof. Distal end of the sheath, the body cavity stricture treatment device according to any one of claims 1 are curved inward so that the distal end surface is in contact with the outer surface of the tube body 3. 5. A hub provided with a valve slidably and liquid-tightly holding the tube body at a proximal end portion of the sheath, wherein the hub has a liquid port. The device for treating a stenosis in a body cavity according to any one of the above. The device for treating a stenosis in a body cavity according to any one of claims 1 to 5 , wherein the device for treating a stenosis in a body cavity has a fixing means for releasably fixing the sheath to the tube body.

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