JP4422578B2 - Stent and stent graft - Google Patents

Description

  The present invention relates to a stent used for the treatment of diseases such as severe pulmonary embolism, superior vena cava syndrome, Bad Chiari syndrome, obstructive jaundice, thrombosis / embolism, and a stent graft used for the treatment of thrombosis / embolism, More specifically, after indwelling for a certain period of time through a catheter in the lumen of a body tubular organ such as a blood vessel, biliary tract, urethra, trachea, etc. and treating the disease as described above, again without damaging the inner wall of the body tubular organ The present invention relates to a stent and a stent graft that can be safely housed in a catheter.

  A stent is an artificial cylindrical structure that is inserted into a body tubular lumen such as a blood vessel in order to support a body tubular organ such as a blood vessel. For example, when a tubular organ such as a blood vessel, gallbladder, esophagus, intestine, or urethra is narrowed or deformed, the stent is inserted into the tubular organ to support the tubular organ. To prevent. A stent that has been widely applied clinically for the purpose of treating arterial stenosis is a cylindrical body formed of a mesh or spring made of stainless steel or a shape memory alloy (NiTi) wire. This cylindrical body can be repeatedly contracted and expanded in the radial direction. In addition, a cylindrical body made of stainless steel or nickel titanate wire as described above is inserted or extrapolated into an artificial blood vessel (graft) made of polyester or fluororesin, and is sutured and fixed. It is considered a blood vessel. This endovascular artificial blood vessel is called a stent graft and is effectively used for the treatment of aneurysms.

  Such a stent or stent graft is placed in an affected area in a blood vessel via a catheter. That is, the stent or stent graft is compressed to a diameter smaller than the inner diameter of the thin pipe-shaped catheter and stored in the catheter, and this is inserted from the incision portion of the peripheral artery (mainly the femoral artery) to the affected portion in the blood vessel. Therefore, the stent or stent graft is pushed out from the catheter, radially expanded to a predetermined diameter, and placed in the affected area in the blood vessel, thereby expanding the arterial stenosis lesion or blocking the aneurysm and simultaneously reconstructing the blood flow. To achieve. The treatment with stents or stent-grafts not only reduces the burden on the patient because the surgical invasion is mild, but can also be applied to aneurysm diseases that have been excluded from the conventional application. It is a beneficial treatment for patients with diseases and diastolic diseases.

As such a stent, for example, (1) it is composed of one continuous elastic knitting wire, and both ends have a plurality of fold-back points of a knitting wire loop structure and spiral from one end. A luminal stent in which a braided wire wound in a spiral shape and a braided wire wound in a spiral shape from the folding point at the other end intersect with each other by periodically changing the upper and lower positions of the braided wire (see Patent Document 1) .), (2) A predetermined number of filaments are twisted in a sine curve shape to form a cylindrical braided braid structure, and both ends of the cylindrical braided braid structure are formed by folding or joining the filaments. A stent (see Patent Document 2), which is formed in a loop structure, and in which each filament is an endless loop with no end as a whole (see Patent Document 2), (3) a main body portion having a proximal portion and a distal portion, and a connection A plurality having an end, a free end, and an outer surface A wire, a connection end of each wire fixed to the distal portion of the main body, each wire forming a spiral shape extending radially from the main body and expanding, and an outer surface of each wire is in contact with the blood vessel wall A thrombus formed to be placed in a blood vessel lumen formed by a blood vessel wall consisting of a maximum diameter of a selected helical shape and an outer surface of each wire, usually continuous, without sharp protrusions A filter (see Patent Document 3), and (4) a blood vessel filter (see Patent Document 4) including a hook composed of a single filament provided as a mooring connecting portion at the tip of the thrombus filter. .) Has been proposed. In addition, as a stent graft having such a stent, for example, (5) a stent in which one or a plurality of filaments are spirally twisted to form a braided structure, and a temporary indwelling stent graft having a graft, (A) The stent is a body portion that can be expanded and contracted in a normal state and expands into a cylindrical shape in a normal state, a tail portion that expands in a normal state and is tapered following the main body portion, and (B) The main body portion of the stent is covered with a graft, and (c) the distal end of the graft can be turned to the distal end of the stent. There has been proposed a temporary indwelling stent graft (see Patent Document 5) that is engaged with an engaging means.
JP-A-9-173469 Japanese Patent Laid-Open No. 11-57021 Special table 2003-521970 gazette Special Table 2002-514102 JP 2001-333987 A

  In the stents described in Patent Documents 1 and 2, both ends of the cylindrical rod-like braid structure are formed into a loop structure by folding or joining the filaments, and each filament is an endless loop with no ends as a whole. Therefore, there is no possibility of damaging the inner wall of the tubular organ when the stent is inserted from the catheter into the tubular organ such as a blood vessel. However, this stent can be stored in the catheter and released again to another place in the tubular organ while it is being released from the catheter in which it is stored into the tubular organ such as a blood vessel. However, once it has been released and placed in a tubular organ such as a blood vessel, there has been a problem that it cannot be stored in a catheter and recovered outside the body.

  The thrombus filter described in Patent Document 3 has a tapered filter portion formed of a plurality of spiral wires, and a portion that extends from the filter portion and contacts a blood vessel wall formed in a cylindrical shape. Therefore, after the thrombus filter stored in the catheter is once released into the blood vessel and indwelled for a long time, it can be stored again in the catheter and recovered outside the body. The thrombus filter is recognized as a hook composed of a single thick filament inserted into the tip of the thrombus filter described in Patent Document 4 related to the prior application of the same applicant. There is a problem that the hook may come off when the loop pulled out from the catheter is engaged and retracted from the blood vessel into the catheter. . In addition, since the hook formed of a single thick filament is not flexible, there is a problem that the hook may damage the blood vessel wall. Furthermore, since the thrombus filter described in Patent Document 3 has a plurality of free ends in a portion in contact with the cylindrical blood vessel wall, there is a risk that these free ends may damage the blood vessel wall. There was a problem such as.

  Further, in the temporary indwelling stent graft described in Patent Document 5, the stent constituting the temporary indwelling stent graft can be freely expanded and contracted. Subsequently, it is composed of a tail portion which is diameter-expanded in a normal state and becomes tapered, and a strut portion in a reduced diameter state provided next to the tail portion, and the distal end of the graft is rotated to the distal end of the stent. Since it is engaged by the engaging means, the temporarily indwelling stent graft that has been temporarily released into the blood vessel can be retracted into the catheter and safely stored. Since the extending strut portion is provided, there is a problem that the stent graft cannot be placed in the blood vessel for a long time.

  The present invention aims to solve this problem.

That is, according to the present invention, the hook-shaped engaging portion can be put into the loop of the loop snare catheter and can be reliably engaged, and the tubular body by the projection of each filament end at the distal end of the filament bundle. It is an object of the present invention to provide a stent that can be free of damage to the inner wall of the organ and that can further reduce the damage caused to the inner wall of the internal tubular organ by the engagement portion. .

In order to achieve the above object, the invention described in claim 1 is a stent in which one or a plurality of filaments are spirally twisted and formed into a braided structure ,
A main body that expands to a cylindrical shape when the stent is normally expanded and contracted, and a tail that is provided following the main body and expands and tapers when the stent is expanded and contracted. And a wire bundle provided subsequent to the tail portion, and a hook formed by bending or bending the wire bundle provided subsequent to the rear end of the wire bundle and the wire. In a stent having an engagement portion in which each filament at the tip of the bundle is integrally welded,
A large number of filaments arranged in a ring-shaped cross section constituting the tail portion twisted in the braid structure are cut at equal intervals at the tail end, and the number of filaments constituting the filament bundle is Less than the number of filaments that make up the tail end, and
A stent characterized in that a portion near the tip of the filament constituting the filament bundle is fixed by being twisted to another adjacent filament that is not cut .

The invention described in claim 2 is the invention described in claim 1,
A large number of filaments arranged in a ring shape in section are cut at every other end of the tail, and
The portion near the tip of the wire constituting the wire bundle is fixed by being twisted to another adjacent wire that is not cut .

The invention described in claim 3 is the invention described in claim 1, wherein the loops formed by folding the line at the tip of the main body part or joining two adjacent line ends are equally spaced. It is characterized by being formed .

  The invention described in claim 4 is the invention described in claim 1, wherein the engaging portion is formed into a circular shape, an elliptical shape, a rhombus shape, or a triangular shape by bending or bending the filament bundle. In addition, each filament at the tip of the filament bundle is integrally welded.

The invention described in claim 5 is the invention described in any one of claims 1 to 4 , wherein the filament is made of a shape memory material, and the diameter of the main body is expanded in a normal state to form a cylinder. The shape is memorized so that the tail is tapered, the shape is memorized so that it is tapered in the normal state, the shape bundle is memorized so that the diameter is reduced in the normal state, and the engaging portion is hooked in the normal state. A structure or a shape memorized so as to have a perforated structure selected from a circle, an ellipse, a rhombus and a triangle, and each filament at the tip of the filament bundle is integrally welded It is.

The invention described in claim 6 is the invention described in claim 5 , wherein the shape memory material is a Ni—Ti based shape memory alloy, a Cu—Al—Ni based shape memory alloy, or a Cu—Zn—. It is an Al-based shape memory alloy.

The invention described in claim 7 is the invention described in any one of claims 1 to 4 , wherein the wire is a metal wire made of stainless steel, titanium, nickel, or tantalum. It is a feature.

The invention described in claim 8 is the invention described in claim 1 , wherein the main body has a diameter of 10 to 40 mm, the main body has a length of 50 to 150 mm, and the tail has a length. Is 10 to 60 mm, the length of the filament bundle is 5 to 20 mm, and the length of the engaging portion is 5 to 20 mm.

The invention described in claim 9 is a stent characterized by storing the stent according to any one of claims 1 to 8 in a sterilized normal state in a pipe-shaped catheter.

In the tenth aspect of the present invention , a cylindrical graft is extrapolated or interpolated on the main body portion of the stent according to any one of the first to ninth aspects, and is fixed with a suture. It is a stent graft characterized by having.

The invention described in claim 11 is a stent graft characterized in that the stent graft according to claim 10 is stored in a sterilized state in a pipe-shaped catheter.

According to the invention described in claims 1, 2, 7, and 8,
A stent formed by braiding one or a plurality of filaments into a braid structure by spirally braiding,
A main body that expands to a cylindrical shape when the stent is normally expanded and contracted, and a tail that is provided following the main body and expands and tapers when the stent is expanded and contracted. And a wire bundle provided subsequent to the tail portion, and a hook formed by bending or bending the wire bundle provided subsequent to the rear end of the wire bundle and the wire. In a stent having an engagement portion in which each filament at the tip of the bundle is integrally welded,
A large number of filaments arranged in a ring-shaped cross section constituting the tail portion twisted in the braid structure are cut at equal intervals at the tail end, and the number of filaments constituting the filament bundle is Less than the number of filaments that make up the tail end, and
Since the vicinity of the tip of the filaments constituting the filament bundle is fixed by being twisted by other adjacent filaments that are not cut ,
1) “Stent formed by braiding one or a plurality of filaments in a spiral structure to form a braided structure , wherein the stent expands in a normal state where the diameter of the stent is freely expandable and becomes a cylindrical body. And a tail portion which is provided following the main body portion so that the diameter thereof can be freely expanded and contracted and is tapered in a normal state, a wire bundle provided subsequent to the tail portion, and a rear end of the wire bundle And an engaging portion formed in the shape of a hook formed by bending or bending the filament bundle provided subsequently, and each filament at the tip of the filament bundle being integrally welded. After being placed in the lumen of a body organ such as a blood vessel for a certain period of time, it can be safely placed without damaging its inner wall. Can be safely removed without damaging the inner wall of the tubular organ. Stored in ether can be recovered from the body, moreover, can be made completely free of the risk of falling out of the engagement portion in the recovered operation,
2) “It is formed in a hook shape formed by bending or bending the filament bundle provided subsequent to the rear end of the filament bundle, and each filament at the tip of the filament bundle is integrally welded. The engagement portion formed in a hook shape can be surely engaged by being put into the loop of the loop snare catheter, and at the tip of the filament bundle. No damage to the inner wall of the internal tubular organ by the projections of each filament end; and
3) “The number of filaments constituting the bundle of bundles, in which a large number of filaments arranged in a ring-shaped cross section constituting the tail portion twisted in the braid structure are cut at equal intervals at the tail ends. However, the number of the filaments constituting the tail end is reduced, and the portion in the vicinity of the tip of the filament constituting the bundle is twisted and fixed to other adjacent filaments that are not cut. The engagement portion can be made more flexible, and therefore damage to the inner wall of the body tubular organ by the engagement portion can be further reduced.
A stent can be provided.

According to the invention described in claim 3 , since the loops formed by folding the filaments or joining the two adjacent filament ends are formed at equal intervals at the distal end of the main body, It is smooth and therefore does not damage the inner wall of the body tubular organ.

According to the invention described in claim 4 , the engaging portion is formed in a circular shape, an elliptical shape, a rhombus shape, or a triangular shape by bending or bending the linear bundle, and the linear bundle Since each filament at the tip is integrally welded, it is possible to reliably engage the engaging portion formed in a circular shape, an elliptical shape, a rhombus shape or a triangular shape into the loop of the loop snare catheter. In addition, it is possible to prevent damage to the inner wall of the body tubular organ due to the projections of the ends of the filaments at the tip of the filament bundle.

According to the invention described in claims 5 and 6 , the filament is made of a shape memory material, the shape of the main body is expanded so as to become a cylindrical shape in a normal state, and the tail is in a normal state. The shape is sometimes memorized so as to be tapered, the shape bundle is memorized so as to be in a diameter-reduced state in a normal state, and the engagement portion is normally in a hook structure, or circular, oval, rhombus and Since the shape is memorized so as to have a perforated structure selected from triangles, a stent having such a complicated structure can be manufactured at low cost.

According to the invention described in claim 9 , since the stent according to any one of claims 1 to 8 is stored in a sterilized state in a pipe-shaped catheter, it can be used immediately in an emergency. Can do.

According to the invention described in claim 10 , the cylindrical graft is extrapolated or inserted into the main body portion of the stent according to any one of claims 1 to 9 , and fixed with a suture. Since it is a stent graft, it can be safely placed in a tubular lumen such as a blood vessel without damaging its inner wall, and even after being placed in a tubular lumen such as a blood vessel for a certain period of time, It is possible to provide a stent graft that can be safely stored in the catheter and recovered outside the body without damaging the inner wall of the tubular device, and that there is no risk of the engagement portion falling off during the recovery operation.

According to the eleventh aspect of the present invention, since the stent graft according to the tenth aspect is stored in a sterilized state in a pipe-shaped catheter, it can be used immediately in an emergency.

  Hereinafter, the present embodiment will be described with reference to the drawings.

  FIG. 1 is an explanatory view of a stent showing an embodiment of the present invention. FIG. 2 is an explanatory view of a stent showing another embodiment of the present invention. FIG. 3 is an explanatory view of a stent showing another embodiment of the present invention. FIG. 4 is an explanatory view of a graft showing another embodiment of the present invention. FIG. 5 is an explanatory view of a stent graft showing another embodiment of the present invention. FIG. 6 is an explanatory view showing a procedure for placing a stent according to an embodiment of the present invention in a blood vessel, wherein (a) shows a state in which the stent is stored in a sheath catheter, and (b) FIG. 2 shows a state where the stent is pushed out from the sheath catheter into the blood vessel, and FIG. 3C shows a state where the stent is placed in the blood vessel. FIG. 7 is an explanatory view showing a procedure for collecting a stent showing an embodiment of the present invention from a blood vessel into a sheath catheter. FIG. 7A shows a loop snare catheter loop at an engaging portion of the stent. (B) shows a state in which the stent is to be stored in the sheath catheter from within the blood vessel, and (c) shows a state in which the stent has been stored in the sheath catheter. .

As shown in FIG. 1, the stent 10 of the present invention is formed in a braided structure by twisting one or a plurality of filaments W spirally. The stent 10 has a cylindrical main body portion 1 that expands in the normal state in which the diameter can be reduced and expands, and a normal diameter expandable in the normal state that is provided in the main body portion 1 and that can be expanded and contracted. It is formed by bending or bending the tail 2 having a tapered shape, the filament bundle 3 provided following the tail 2, and the filament bundle 3 provided subsequent to the rear end of the filament bundle 3. And an engaging portion 4 which is formed in a hook shape and in which each filament at the tip of the filament bundle 3 is integrally welded.

  Stents having such a “braid structure” are known in the art as described in Patent Documents 1 and 2, for example. As described in these patent documents, the stent 10 according to the present invention may have a “braid structure” in which a single filament W is spirally twisted into a braid structure. In addition, it may have a “braid structure” in which a plurality of filaments W are twisted in a spiral shape to form a braid structure.

  Since the stent 10 has a “braid structure” in which one or a plurality of filaments W are spirally twisted together, it is extremely flexible. In addition, the stent 10 of the present invention is composed of a main body portion 1, a tail portion 2, a filament bundle 3, and an engaging portion 4, and these are formed by a continuous “braid structure”. Is not formed. Furthermore, since the said bundle 3 and the engaging part 4 are comprised by many continuous filaments, they are formed very flexibly.

Therefore, the stent 10 of the present invention can prevent the inner wall of the internal tubular organ from being narrowed or deformed in order to prevent narrowing or deformation of the internal tubular organs such as blood vessels, gallbladder, esophagus, intestine, and urethra. It will not be damaged, and even if it is recovered after indwelling for a certain period of time, it will not damage the inner walls of these tubular organs. Further, when the wire bundle 3 and the engaging portion 4 are constituted by a large number of continuous wires, there is no risk of the engaging portion falling off during the collecting operation. Moreover, the engaging portion 4 is formed in a hook shape formed by bending or bending the filament bundle 3 provided subsequent to the rear end of the filament bundle 3 and the tip of the filament bundle 3. Are integrally welded , the engaging portion 4 formed in a hook shape can be put into the loop of the loop snare catheter to be surely engaged. There can be no damage to the inner wall of the internal tubular organ due to the protrusion at the end of each of the filaments W.

And in the stent 10 of the present invention, a large number of filaments W arranged in a cross-sectional ring shape constituting the tail portion 2 twisted in the braid structure are cut at equal intervals at the tail 2 end, The number of the filaments W constituting the filament bundle 3 is less than the number of the filaments W constituting the end of the tail portion 2, and the vicinity of the tip of the filament W constituting the filament bundle 3 is: It is twisted and fixed to other adjacent filaments that are not cut. A large number of filaments W arranged in a ring shape in the cross section are preferably cut at every other end of the tail 2 and a portion near the tip of the filament W constituting the filament bundle 3 is cut. It is fixed by being twisted by other adjacent wire W which is not made. In this way, a large number of filaments W arranged in a cross-sectional ring shape that constitutes the tail portion 2 twisted in the braided structure are cut at equal intervals at the ends of the tail portion 2 to constitute the filament bundle 3 The number of the filaments W to be formed is less than the number of the filaments W constituting the tail 2 end, and the portion near the tip of the filament W constituting the filament bundle 3 is not cut and adjacent. When the wire is twisted and fixed to another wire, the engaging portion 4 can be made more flexible, and therefore, the damage to the inner wall of the body tubular organ by the engaging portion 4 can be further reduced. Can do.

  In the present invention, loops are formed at equal intervals at the front end of the main body 1 by folding the line W or joining two adjacent line ends. In this way, when the loop of the line W is folded at the front end of the main body part 1 or a loop formed by joining two adjacent line ends is formed at equal intervals, the front end of the stent 10 becomes smooth. Does not damage the inner wall of the body tubular organ.

  In addition, as shown in FIGS. 2 to 4, in the present invention, the engaging portions 14, 24, and 34 are each formed into a circular shape, an elliptical shape, a rhombus shape, or a triangular shape by bending or bending the filament bundle 3. In addition, each filament W at the tip of the filament bundle 3 is integrally welded. As described above, the engaging portions 14, 24, and 34 are formed in a circular shape, an elliptical shape, a rhombus shape, or a triangular shape by bending or bending the linear bundle 3, respectively, and the leading ends of the linear bundle 3 Are integrally welded, the engaging portions 14, 24, 34 formed in a circular shape, an elliptical shape, a rhombus shape, or a triangular shape are connected to the loop of the loop snare catheter (see 103a in FIG. 7). .) Can be reliably engaged with each other, and damage to the inner wall of the body tubular organ due to the projections of the ends of the filament bundle at the distal end of the bundle can be prevented.

  In the present invention, the filament W is made of a shape memory material, the shape of the main body 1 is expanded so as to be a cylindrical shape in a normal state, and the shape of the tail 2 is a tapered shape in a normal state. The shape of the filament bundle 3 is memorized so that the diameter is reduced in the normal state, and the engaging portions 4, 14, 24, and 34 are selected from the hook structure or the circular shape, the elliptical shape, the rhombus shape, and the triangular shape in the normal state. The shape can be memorized so as to have a perforated structure. The shape memory material is preferably a Ni—Ti based shape memory alloy, a Cu—Al—Ni based shape memory alloy, or a Cu—Zn—Al based shape memory alloy. As described above, the filament W is made of a shape memory material, and the body portion 1 is expanded in diameter in a normal state so as to have a cylindrical shape, and the tail portion 2 is stored in a shape in a tapered shape in a normal state. The shape of the filament bundle 3 is memorized so as to be reduced in the normal state, and the engagement portion 4 is formed in a hook structure or a perforated structure selected from a circle, an ellipse, a rhombus and a triangle in the normal state. If shape memory is used, a stent having such a complicated structure can be manufactured at low cost.

  Unless it is contrary to the object of the present invention, the wire W in the present invention may be a metal wire made of stainless steel, titanium, nickel or tantalum.

  In the stent 10, 20, 30, 40 of the present invention, the diameter of the main body 1 is preferably 10 to 40 mm, the length of the main body 1 is 50 to 150 mm, and the length of the tail 2 is 10 to 60 mm. The length of the line bundle is 5 to 20 mm, and the length of the engaging portion is 5 to 20 mm.

  In the present invention, the stent 10, 20, 30, 40 according to any one of claims 1 to 10 may be stored in a sterilized state in a pipe-shaped catheter. Thus, if the stent 10, 20, 30, 40 according to any one of claims 1 to 10 is stored in a sterilized state in a pipe-shaped catheter, it can be used immediately in an emergency. be able to.

  As shown in FIG. 5, according to the stent graft 50 of the present invention, the cylindrical graft (artificial blood vessel) 5 is a stent 10, 20, 30, 40 according to any one of claims 1 to 10. Are extrapolated or inserted into the main body 1 and fixed with sutures (not shown). Thus, the cylindrical graft 5 is extrapolated or inserted into the main body 1 of the stent 10, 20, 30, 40 according to any one of claims 1 to 10, and fixed with a suture. With the stent graft being made, it can be safely placed in the lumen of a body tubular organ such as a blood vessel without damaging its inner wall, and even after being placed in a body tubular organ such as a blood vessel for a certain period of time, It is possible to provide a stent graft that can be safely stored in a catheter and recovered outside the body without damaging the inner wall of the internal tubular organ, and that there is no risk of the engagement portion falling off during the recovery operation. .

  The stent graft according to claim 12 may be stored in a sterilized state in a pipe-shaped catheter. Thus, if the stent graft according to claim 12 is stored in a sterilized state in a pipe-shaped catheter, it can be used immediately in an emergency.

  [I] A method of placing the stent of the present invention in a body tubular organ, for example, a pulmonary trunk, will be described as follows.

  (1) As shown in FIG. 6A, a sheath catheter 101 in which the stent 10 is stored and the pusher catheter 102 is inserted so as to abut against the engaging portion 4 of the stent 10 is inserted into a peripheral vein ( The sheath catheter 101 in which the stent is stored is made to reach the pulmonary artery main trunk 104 by being inserted along a guide wire (not shown) arranged in advance mainly from an incision portion of the femoral vein.

  (2) As shown in FIG. 6B, after the stent 10 stored in the sheath catheter 101 reaches the pulmonary artery main trunk 104, the pusher catheter 102 is brought into contact with the engaging portion 4 of the stent 10. The pusher catheter 102 is fixed (supported) so as not to move, and then the stent 10 is sequentially pushed out from the sheath catheter 101 to the pulmonary artery trunk 104 by pulling the sheath catheter 101 in the direction of the arrow (the direction of the hand).

  (3) As shown in FIG. 6C, the main body 1, tail 2, filament bundle 3 and engagement portion 4 of the stent 10 are sequentially pushed out to the pulmonary artery main trunk 104 to self-expand the main body 1. Then, the main body 1 is closely fixed to the blood vessel wall, and then the tail 2 is expanded to place the stent 10 in the main pulmonary artery trunk.

  [II] A method for recovering the stent of the present invention from a body tubular organ, for example, a pulmonary trunk, will be described as follows.

  (1) As shown in FIG. 7A, a guide wire (not shown) in which a sheath catheter 101 having a pusher catheter 102 inserted therein is disposed in advance from an incision in a peripheral vein (mainly a femoral vein). ) To reach the pulmonary artery main trunk 104, and then the loop snare catheter 103 is pushed out to engage the loop 103 a formed at the distal end thereof with the engaging portion 4 of the stent 10.

  (2) As shown in FIG. 7B, while engaging the loop 103a of the loop snare catheter 103 with the engaging portion 4 of the stent 10, the loop snare catheter 103 is fixed (supported) so as not to move, Next, by pushing the sheath catheter 101 in the direction of the arrow (the direction away from the hand), the engaging portion 4, the filament bundle 3, the tail portion 2, and the body portion 1 of the stent 10 are sequentially inserted into the sheath catheter 101. The entire 10 is stored in the sheath catheter 101.

  (3) As shown in FIG. 7C, the sheath 10 containing the stent 10 is pulled out in the hand direction and the stent 10 is recovered.

  As mentioned above, although the method of indwelling the stent of this invention to a body tubular organ, for example, a pulmonary artery main trunk, and the method of collect | recovering it were demonstrated, the stent graft of this invention can be demonstrated similarly.

(I) Treatment of severe pulmonary embolism There is a method of treating severe pulmonary embolism by permanently placing a stent beside the thrombus formed in the main trunk of the pulmonary artery, dissolving the thrombus, and allowing blood flow to resume. Although it has been proposed, even after the treatment of such severe pulmonary embolism has been completed, if the stent is permanently placed in the pulmonary artery trunk, there is a problem that a thrombus is generated in the stent itself. Therefore, it was proposed to recover the stent after the treatment of such severe pulmonary embolism was completed, but there is a risk of damaging the inner wall of the pulmonary artery trunk during the recovery of the stent, so the stent can be recovered safely. It was difficult to do. However, the stent of the present invention can be safely placed in the pulmonary artery trunk without damaging the inner wall thereof, and even after being placed in the pulmonary artery trunk for a certain period of time, the inner wall of the pulmonary artery trunk is not damaged. Since it can be safely stored in the catheter and recovered outside the body, and there is no risk of the engagement portion falling off during the recovery operation, it is effectively used for the treatment of severe pulmonary embolism.

(B) Treatment of superior vena cava syndrome and butchiari syndrome Upper vena cava syndrome is a disease that is secondary to diseases such as lung cancer and mediastinal lymph node metastasis. It is a secondary disease. These diseases can be ameliorated by permanently placing stents in the respiratory tract, but radiation therapy can be used to treat diseases such as lung cancer, mediastinal lymph node metastasis, primary liver cancer, and metastatic liver cancer. After successful treatment with chemotherapy or the like, the stent has a problem of causing complications by moving as a foreign object or breaking. However, the stent of the present invention can be safely placed in the airway without damaging the inner wall of the airway, and can be safely catheterized without damaging the inner wall of the body tubular organ even after being placed in the airway for a certain period of time. It can be stored inside and recovered outside the body, and since there is no risk of the engagement portion falling off during the recovery operation, it is effectively used for the treatment of superior vena cava syndrome and butchiari syndrome.

(C) Treatment of obstructive jaundice Obstructive jaundice is a disease caused by diseases such as pancreatic cancer and biliary tract cancer. Diseases such as pancreatic cancer and biliary tract cancer are treated after the yellowing of PTCD or ENBD temporarily placed in the biliary tract, but because the tube is exposed outside the body, it deteriorates the mobility of the patient and adversely affects the intestinal circulation There was a problem of giving. However, the stent of the present invention can excrete bile into the body and can be safely placed in the airway without damaging the inner wall of the biliary tract, and even after being placed in the airway for a certain period of time. It can be safely stored in the catheter and recovered outside the body without damaging the inner wall, and there is no risk of the engagement part falling out during the recovery operation, making it effective in treating jaundice due to obstruction. Used.

(D) Treatment of thrombosis and embolism Although a catheter for sucking a thrombus is already on the market, it applies hydrodynamics, so the applicable mother blood vessel diameter is only 1 cm or less. Since it is not uncommon for thrombus in severe pulmonary embolism and deep vein thrombosis causing it to reach 2 cm or more, there is a problem that it cannot be handled by a commercially available suction catheter. However, since the stent of the present invention can be combined with a balloon catheter to collect a thrombus of 2 cm or more in the stent, it not only enhances the effectiveness of the conventional suction catheter but also as a thrombus remover as it is. Can be safely placed on the pulmonary artery trunk without damaging the inner wall of the pulmonary artery trunk, and is safe without damaging the inner wall of the pulmonary artery after being placed on the pulmonary artery trunk for a certain period of time. It can be stored in the catheter and recovered outside the body, and since there is no risk of the engagement portion falling off during the recovery operation, it is effectively used for the treatment of thrombosis and embolism.

It is explanatory drawing of the stent which shows one embodiment of this invention. It is explanatory drawing of the stent which shows other one Embodiment of this invention. It is explanatory drawing of the stent which shows other one Embodiment of this invention. It is explanatory drawing of the graft which shows other one Embodiment of this invention. It is explanatory drawing of the stent graft which shows other one Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the procedure which indwells the stent which shows one embodiment of this invention in the blood vessel, Comprising: (a) shows the state which stored the stent in a sheath catheter, (b) shows a stent in a sheath. A state where the catheter is pushed out into the blood vessel is shown, and (c) shows a state where the stent is placed in the blood vessel. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the procedure which collect | recovers the stent which shows one embodiment of this invention in the sheath catheter from the inside of a blood vessel, Comprising: (a) engaged the loop of the loop snare catheter with the engaging part of the stent. The state is shown, (b) shows a state where the stent is being stored in the sheath catheter from within the blood vessel, and (c) shows a state where the stent has been stored in the sheath catheter.

DESCRIPTION OF SYMBOLS 1 Main body part 2 Tail part 3 Line bundle 4, 4, 24, 34 Engagement part 5 Graft 10, 20, 30, 40 Stent 50 Stent graft 101 Sheath catheter 102 Pusher catheter 103 Loop snare catheter 103a Loop 104 Pulmonary artery main trunk W line

Claims (11)

A stent formed by braiding one or a plurality of filaments into a braided structure , wherein the stent expands in a normal state to be freely expandable and expands into a cylindrical shape; Following the main body, the tail that is tapered and expands in the normal state to be freely contractible and expandable, the filament bundle provided following the tail, and the rear end of the filament bundle In a stent having an engagement portion that is formed in a hook shape formed by bending or bending the provided filament bundle, and in which each filament at the tip of the filament bundle is integrally welded ,
A large number of filaments arranged in a ring-shaped cross section constituting the tail portion twisted in the braid structure are cut at equal intervals at the tail end, and the number of filaments constituting the filament bundle is Less than the number of filaments that make up the tail end, and
A stent characterized in that a portion in the vicinity of the distal end of the filament constituting the filament bundle is fixed by being twisted to another adjacent filament that is not cut . A large number of filaments arranged in a ring shape in section are cut at every other end of the tail, and
The stent according to claim 1 , wherein a portion in the vicinity of the tip of the filament constituting the filament bundle is fixed by being twisted to another adjacent filament that is not cut . The stent according to claim 1, wherein loops formed by folding of the filaments or joining two adjacent filament ends are formed at equal intervals at the tip of the main body. The engaging portion is formed into a circular shape, an elliptical shape, a rhombus shape, or a triangular shape by bending or bending the filament bundle, and each filament at the tip of the filament bundle is integrally welded. The stent according to claim 1 . The filament is made of a shape memory material, the main body is expanded in diameter in a normal state so as to have a cylindrical shape, and the tail is in a shape of a taper in a normal state, and the linear The shape of the bundle is memorized so as to be reduced in diameter, and the engagement portion is memorized so as to have a hook structure or a perforated structure selected from a circle, an ellipse, a rhombus, and a triangle at the normal time. The stent according to any one of claims 1 to 4 , wherein The stent according to claim 5 , wherein the shape memory material is a Ni—Ti based shape memory alloy, a Cu—Al—Ni based shape memory alloy, or a Cu—Zn—Al based shape memory alloy. The stent according to any one of claims 1 to 4 , wherein the filament is a metal wire made of stainless steel, titanium, nickel, or tantalum.   The diameter of the main body is 10 to 40 mm, the length of the main body is 50 to 150 mm, the length of the tail is 10 to 60 mm, and the length of the filament bundle is 5 to 20 mm, And the length of an engaging part is 5-20 mm, The stent of Claim 1 characterized by the above-mentioned. A stent comprising the stent according to any one of claims 1 to 8 stored in a pipe-shaped catheter. A stent graft, wherein a cylindrical graft is extrapolated or inserted into the main body of the stent according to any one of claims 1 to 9, and is fixed with a suture. The stent graft according to claim 10, wherein the stent graft is stored in a sterilized state in a pipe-shaped catheter.

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