JP2011251117A - Polymer stent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer stent giving little influence to a living body while dwelling in a lumen and improving imaging/measuring accuracy of an MRI image, in which slit deformation giving a ratchet function is prevented and the ratchet function of the stent is maintained for a long period.SOLUTION: The polymer stent 1 is constituted by arranging a plurality of T shape unit parts 2 each comprising a head part 3 and body part 4 side by side and mutually coupling the same at the head parts and integrating the same. Hook shape protrusions 5 each having an oblique side and a vertical side are formed in one sides of the long sides of the body parts 4 of the respective unit parts 2 and slits in a vertical direction to the length direction of the body parts 4 are formed in the head parts 3. Width variable parts 7 are formed in the sides of the body parts 4 where the hook shape protrusions 5 are not formed or the tilting angle of the slits 6 are made variable at the end sides of the slits 6 of the head parts 3. Thus, the movement of the body part 4 in a direction reducing the diameter of the ring shape is stopped and the movement of the body parts 4 in a direction increasing the diameter of the ring shape is made possible when forming the ring part by rounding the body parts 4 and inserting the same into the slits 6.

Description

  The present invention relates to a polymer stent, and more particularly to a polymer stent that is bent into a tubular shape and placed in a lumen.

  As a treatment method for diseases caused by vascular diseases such as myocardial infarction and cerebral infarction, a blood vessel is expanded with a balloon catheter and a stent is placed. In general, a metal stent is used. Metal stents remain permanently in the body, so they cannot be applied to young people whose body size changes, and there is a risk of recurrence of stenosis due to prolonged mechanical stimulation .

  A polymer stent does not have the disadvantages of a metal stent, and a stent made of a biodegradable polymer has the advantage of eliminating the stress caused by the permanent presence of the stent in the body. Recently, many polymer stents are also used.

  There is a technique for a polymer stent as shown in the following patent document, which discloses an overlapping edge having a series of interlocking protrusions and holes, where the stent is part of the lumen wall. An intraluminal stent consisting of a cylindrical sheet that ratchets when expanded to an open position that supports the device. In Patent Document 2, a plurality of ladder-like elements are connected in series, and each ladder-like element is provided with two long ribs and two end crosspieces fixed to the long ribs. A ladder-type expandable stent that can be expanded from a reduced diameter to an expanded diameter and prevents sliding back to a reduced diameter by forming a variable distance between the end crosspieces of adjacent ladder-like elements Is described.

  Patent Document 3 includes at least one continuous slide / fixed radius element and at least one ratchet mechanism having one connecting element and a plurality of stops, and the ratchet mechanism has a radius from a reduced diameter to an expanded diameter. An expandable stent is described having a slide / fixed radius element that allows unidirectional sliding of the element and prevents radial recoil from the expanded diameter.

  Patent Document 4 is based on the present inventor, and is formed by connecting a plurality of T-shaped unit parts including a head part and a trunk part extending from the head part, on one side part or both side parts of the trunk part. A polymer stent is described that has at least one protrusion, the head having an opening that passes through the body and engages the protrusion.

  According to Patent Document 1, since the stent is formed in a cylindrical sheet, the stent has high rigidity, and it is difficult to make the end of the cylindrical sheet project and have a circular cross section in the lumen. There was a possibility that it could not adhere inside. The ladder-type expandable stent according to Patent Document 2 has a complicated shape and structure, and since the resistance applied to the long ribs is large, the stent diameter may not be easily variable. A tab stop for preventing sliding in the shrinking direction is provided on the long rib, and the end crosspiece is engaged with the tab stop, and the long rib and the end crosspiece are formed at a right angle. When the tab stop works due to the movement of the long rib, the end crosspiece is distorted and the stent is deformed.

  The expandable stent having a slide / fixed radius element according to Patent Document 3 is complicated in shape and structure, so that complicated and difficult processes are unavoidable in processing and manufacturing, and also prevents reaction to the diameter at the time of reduction. There is a problem that it is difficult to hang the tab because the tab that is hooked on the stop portion is small.

  Patent Document 4 is proposed by the present inventor in order to solve the structural problems in the prior art polymer stents shown in Patent Documents 1 to 3 and the like. It is a thing.

  FIG. 16 is a development view of a polymer stent provided with a ratchet mechanism shown in Patent Document 4, and this polymer stent has a T-shape composed of a head H and an elongated rectangular trunk R extending from the head. It is configured as a single sheet-like member in which a plurality of unit portions are connected. The trunk portion R is formed with a hook-like projection P composed of an oblique side portion and an upright side portion, and the head portion H is formed with a slit SL. N is a junction. The body portion R of each unit portion of the polymer stent of FIG. 16 is rounded, and the tip is inserted into the slit SL to form each unit in a ring shape as shown in FIG. 17, resulting in a cylindrical stent as a whole.

  One of the T-shaped unit parts is shown in FIG. 18A, and the slit SL formed in the head H can be inserted through the body part R at the width of the part without the hook-shaped protrusions. It consists of an opening Q having a height smaller than the combined width of the hook-like projections and a linear notch L extending in the extending direction of one side thereof, as shown in FIG. 18 (b). The length of L is such that the hook-like protrusion P of the body R can be inserted. A claw portion is formed by the linear cut portion L and the upper side of the opening Q adjacent thereto. This nail | claw part makes the effect | action which latches a projection part.

  As shown in FIG. 18C, when the body R is inserted into the slit SL of the head H and then an action of expanding the diameter of the ring-shaped body R is applied. Therefore, the hook-like projection P can pass through the slit SL. When the action of trying to narrow the diameter of the trunk portion R is applied, even if the upright side portion of the hook-shaped protrusion P tries to pass through the cut portion L of the slit SL, the hook portion locks the hook-shaped protrusion P. Therefore, the hook-shaped protrusion P cannot pass through the slit SL.

  19 (a) and 19 (b) are diagrams illustrating a situation in which a polymer stent is placed in a lumen such as a blood vessel. FIG. 19A is a cross-sectional view showing a state in which a cylindrical polymer stent as shown in FIG. 17 is inserted into a lumen with a smaller diameter. A balloon B (shown by a dotted line) in a contracted state is inserted in the center, and a polymer stent ST in a contracted state is attached to the balloon B and inserted into the lumen. When the inner balloon B is inflated after the polymer stent ST is inserted into a predetermined position, it becomes as shown in FIG. 19B. After the polymer stent ST is expanded and fixed in accordance with the inner diameter of the lumen, the balloon B is fixed. By extracting, the polymer stent is placed in the lumen.

  As shown in FIG. 20 (a), this polymer stent is formed in the body portion R at the claw portion formed by the linear cut portion L of the slit SL in each unit portion and the upper side of the opening Q adjacent thereto. When the upright side portion of the hook-shaped protrusion P is locked, movement in the direction in which the ring-shaped body portion is reduced in diameter (movement of the body portion R in the right direction in the drawing) is prevented. Movement in the direction in which the body part expands (movement of the body part R in the left direction in the figure) becomes possible.

  Thus, the hook-shaped protrusion P prevents the diameter of the stent from being reduced, so that the size of the ring shape of each unit part constituting the polymer stent is maintained, and the function of preventing the diameter of the lumen from being reduced is provided. It is done. N is a joint portion as a member for connecting the body portions of the plurality of unit portions, and by attaching this member, the shape of the cylindrical polymer stent can be further stabilized. At the time of mounting the joint portion, the notch at the tip on the joint portion side corresponding to the notch formed at the tip of the body portion R of each unit portion is engaged and fixed and welded.

  The polymer stent that is expanded by the balloon catheter to be placed in the lumen receives a strong pressure from the inside, and the head portion H and the trunk portion overlap each other where the trunk portion R passes through the slit SL. Since the pressure from the pipe and the body portion R are passed through the slit SL and are subjected to the frictional force generated by the tension, deformation occurs, and the linear cut portion L of the slit SL is expanded and deformed as shown in FIG. Can be. When the linear cut portion L is thus expanded, the upright side portion of the flange-like protrusion P of the trunk portion R is not locked to the slit SL, and resists pressure in the direction in which the polymer stent is reduced in diameter. There is a problem that the lumen wall cannot be supported and the function as a stent is impaired.

JP 7-531 A JP 2002-540841 A Special Table 2004-515307 JP 2006-68250 A

  As a stent that is placed in the lumen after surgery for cardiovascular disease, a metal stent is excellent in strength but inflexible, remains permanently in the body, and stresses the biological duct. In addition to this, if the metal stent remains in the body, the image by MRI (Magnetic Resonance Imaging) is affected, which makes diagnosis difficult. In addition, metal stents have poor flexibility, and are likely to give mechanical stimulation and stress to the blood vessel wall, leading to thickening of the defective wall and causing restenosis.

  The polymer stent eliminates the stress that is a problem in metal stents, but the polymer has a low elastic modulus and strength compared to metal stents, so the shrinkage restraining force is small, and it tends to cause creep deformation, so it contracts for a long time. However, if the ratio is reduced or the ratio of reduction is increased, permanent deformation occurs and restoration / expansion cannot be performed.

  Therefore, while a polymer stent can compensate for such drawbacks of a metal stent, creep deformation is likely to occur, so that it is difficult to realize a necessary function in a network structure as in the case of a metal stent. In order to maintain the cylindrical state of the polymer stent, the polymer stent having a ratchet mechanism in which the hook-shaped projections are locked to the slits can provide the same shape retention strength as that of metal, but when expanded, In some cases, the ratchet mechanism does not work due to the deformation of the slit caused by a strong force.

  As shown in Patent Document 4, a polymer stent having a connecting portion by a ratchet mechanism can obtain the same strength as that of a metal stent, but the ratchet may not function and may contract, and this is due to a friction force stent. This is considered to be caused by deformation of the structure, particularly the ratchet mechanism.

  Therefore, in the polymer stent that maintains the cylindrical shape by the ratchet mechanism, the shape / structure is simplified, the processing / manufacturing is facilitated, and the ratchet mechanism is deformed by the frictional force due to the expansion operation of the stent. There was a need to ensure that its function was not impaired.

  The present invention has been made to solve the above-mentioned problems, and a polymer stent according to claim 1 of the present invention includes a plurality of T-shaped unit portions each including a head and an elongated trunk extending from the head. It is formed side by side and is integrally formed so as to be connected to each other at the head, and each body is rounded and inserted into a slit formed in the head to form a ring shape. A polymer stent that is placed in a lumen in a cylindrical state, wherein the body portion is inserted through each of the head portions to form a slit in a direction substantially perpendicular to the direction of the body portion, By a link shape that is elastically deformable so that at least one hook-like projection is formed on one side of the long side of the body and the width of the body is reduced on the side facing the one side of the long side A variable width portion is formed, The width from the top of the protrusion to the opposite side of the width variable part on the opposite side is greater than the longitudinal length of the slit in the head, and the hook-shaped protrusion formed on the body passes through the slit in the head When forming the T-shaped unit into a ring shape by rounding the body part and inserting it into the slit of the head part, having an oblique side part and an upright side part engaged with the slit. Further, due to the elastic deformation of the variable width portion in the body portion, the portion of the hook-like projection portion can pass through the slit, and the movement of the barrel portion in the direction of reducing the diameter of the ring shape is caused by the movement of the hook-like projection portion. The upright side portion is locked by coming into contact with the end side of the slit, and the body portion can be moved in the direction of expanding the ring shape by passing from the oblique side portion of the hook-like projection portion. What I did A.

  The polymer stent according to claim 2 of the present invention is integrally formed so that a plurality of T-shaped unit portions each including a head portion and an elongated trunk portion extending from the head portion are juxtaposed and connected to each other at the head portion. A polymer stent that is placed in a lumen in a state where the body is rounded and inserted into and locked in a slit formed in the head to form a ring shape, which is cylindrical as a whole. Each of the heads is inserted with the body portion to form a slit in a direction substantially perpendicular to the direction of the body portion, and at least one hook-shaped protrusion on one side of the long side of each body portion. A variable width portion is formed by a link shape that is elastically deformable so as to expand the width of the body portion on the side opposite to one side of the long side, and is formed in a bowl shape formed on the body portion The protrusion passes through the slit in the head. And a side opposite to the top of the hook-shaped protrusion when the variable width portion of each of the body portions is not deformed. When the width to the width variable portion edge is smaller than the longitudinal length of the slit in the head, each of the body portions is rounded and inserted into the slit of the head to make each T-shaped unit into a ring shape The width from the top of the hook-shaped protrusion to the opposite width variable portion edge when the width of the body portion of the width variable portion is expanded by the frictional action with the side of the slit in contact with the width variable portion edge It is larger than the longitudinal length of the slit in the head, and the movement in the direction in which the trunk portion reduces the diameter of the ring is locked by the upright side portion of the hook-shaped projection contacting the end of the slit. And the torso Movement in the direction of diameter of the ring shape is obtained as is possible by passing from the hypotenuse portion of the hook-like projections.

  A polymer stent according to a third aspect of the present invention is the polymer stent according to the second aspect, wherein a hook-like protrusion is formed on an outer side of the variable width portion, and the hook-like protrusion is on the opposite side of the trunk. The movement in the direction of reducing the diameter of the ring shape of the body portion together with the portion acts so as to be locked.

  The polymer stent according to claim 4 of the present invention is integrally formed so that a plurality of T-shaped unit portions including a head portion and an elongated trunk portion extending from the head portion are juxtaposed and connected to each other at the head portion. A polymer stent that is placed in a lumen in a state where the body is rounded and inserted into and locked in a slit formed in the head to form a ring shape, which is cylindrical as a whole. Each of the heads is inserted with the body portion to form a slit in a direction substantially perpendicular to the direction of the body portion, and at least one hook-shaped protrusion on one side of the long side of each body portion. Is formed, the width from the top of the bowl-shaped projection of the trunk to the opposite edge is larger than the longitudinal length of the slit in the head, and the bowl-shaped projection formed on the trunk is Slanting on the side passing through the slit in the head A chevron-shaped protrusion formed on the body when the body is rounded and inserted into the slit on the head. A narrow slot extending in a direction perpendicular to the slit is extended to the end of the slit on the side where the edge on the non-passing side passes, and another narrow slot parallel to the extended narrow slot Is formed with a thin band-shaped connecting portion interposed therebetween, and a substantially 〒-shaped through hole is formed together with the slit, and each body portion is rolled and inserted into the slit in the head portion of the T-shaped unit. When the body portion is formed into a ring shape, the thin connecting portion connected to the slit is elastically bent by the pressing action of the edge on the side of the body portion where the hook-shaped protrusion is not formed, so that the vertical direction of the slit is increased. The length of the direction expands and the body passes The movement of the body portion in the direction of reducing the diameter of the ring shape is stopped by the upright side portion of the hook-shaped projection portion coming into contact with the slit, and the body portion expands the ring shape. Movement in the radial direction is made possible by passing through the oblique side portion of the hook-shaped projection.

  The polymer stent according to claim 5 of the present invention is integrally formed so that a plurality of T-shaped unit portions including a head portion and an elongated trunk portion extending from the head portion are juxtaposed and connected to each other at the head portion. A polymer stent that is placed in a lumen in a state where the body is rounded and inserted into and locked in a slit formed in the head to form a ring shape, which is cylindrical as a whole. In addition, at least one hook-like protrusion is formed on one side of the long side of each of the trunk parts, and the hook-like protrusion formed on the trunk part is a side that passes through a slit in the head. Each having a slanted side portion and an upright side portion that is latched by the slit, and the flange-like projections of the trunk portion pass through the head in a direction inclined with respect to the width direction of the trunk portion. A slit of possible length is formed and the slit A peninsula-shaped tab portion is formed by a slot that circulates most of the periphery of the lid, and the base portion of the peninsula-shaped tab portion is biased toward the hook-shaped projection side in the width direction of the trunk portion The tab portion is elastically deformed at the base portion thereof so that the slanted side portion of the hook-like projection of the trunk portion passes through the slit so that the inclined slit faces the width direction of the trunk portion. The portion of the hook-shaped projection portion of the tab portion can pass through the slit, and after the passage of the hook-shaped projection portion, the deformation of the base of the tab portion is restored, so that the slit is inclined and the upright side portion of the hook-shaped projection portion The movement of the body portion in the direction of reducing the diameter of the ring shape is retained so that the body portion is expanded in the diameter of the ring shape. As possible by passing through the hypotenuse of One in which the.

  The polymer stent according to claim 6 of the present invention is integrally formed so that a plurality of T-shaped unit portions including a head portion and an elongated trunk portion extending from the head portion are juxtaposed and connected to each other at the head portion. A polymer stent that is placed in a lumen in a state where the body is rounded and inserted into and locked in a slit formed in the head to form a ring shape, which is cylindrical as a whole. In addition, at least one hook-like protrusion is formed on one side of the long side of each of the trunk parts, and the hook-like protrusion formed on the trunk part is a side that passes through a slit in the head. Each of the heads is formed with a bent slit that is a direction that intersects the length direction of the body as a whole. In front of the slit A portion of the body portion on which the hook-like protrusion is not formed is surrounded by a thin band-like connecting portion partitioned by a cutout portion so as to circulate around the portion, so that at least the hook-like protrusion of the body portion is formed. The connecting portion that surrounds the portion of the slit that is not bent is bent and elastically deformable, and the height from the upper end to the lower end of the slit is the top of the bowl-shaped protrusion in the trunk portion The width of the ridge-shaped protrusion is formed when each of the body portions is rounded and inserted into the slit of the head to make each T-shaped unit into a ring shape. The height from the upper end to the lower end of the slit is formed by elastically deforming and extending the shape of the bent connecting portion that presses the lower end side of the slit by the edge portion of the body portion that is not formed and surrounds the slit. The trunk portion is larger than the width from the top of the bowl-shaped protrusion of the trunk section to the opposite side, and the trunk section can pass through the slit, and the trunk section moves in the direction of reducing the diameter of the ring shape. The upright side portion of the protruding portion is locked by contacting the slit, and the body portion can be moved in the direction of expanding the ring shape by passing from the oblique side portion of the hook-like protruding portion. It is what you have.

  The polymer stent according to claim 7 of the present invention is the polymer stent according to claim 6, wherein the slit in each of the heads is formed in a direction substantially perpendicular to the direction of the long side of the trunk. And a bent portion formed so as to be connected to a shape that bends to the slit main portion on the side of the body portion where the hook-shaped protrusion is not formed. .

  The polymer stent according to an eighth aspect of the present invention is the polymer stent according to the sixth aspect, wherein each of the slits in the head portion has a substantially three-letter shape with respect to the long side direction of the trunk portion. The most of the slits on the side where no protrusions are formed are surrounded by a thin strip-shaped connecting part and bent so as to project into a peninsula at the surrounding cutout part.

  The polymer stent according to a ninth aspect of the present invention is the polymer stent according to the sixth aspect, wherein the slit in each of the heads is in a direction substantially perpendicular to a long side direction of the trunk part, and the slit of the trunk part of the slit is formed. Three sides on the side where the hook-shaped protrusions are not formed are surrounded by a connecting portion comprising a spring portion bent in a zigzag shape on both sides in the longitudinal direction of the slit and a connecting portion connecting the tip side thereof, and the connecting portion It is made into the shape which protrudes in a peninsula shape in the cut-out part of the circumference | surroundings.

  A polymer stent according to a tenth aspect of the present invention is the polymer stent according to any one of the fourth, sixth to ninth aspects, and generally intersects with the length direction of the trunk portion of the slit formed in each head. Each of the heads is formed with an auxiliary slit in a direction parallel to the direction and longer than the length of the portion in which the slit and the cutout portion in the direction are combined.

  A polymer stent according to an eleventh aspect of the present invention is integrally formed so that a plurality of T-shaped unit portions including a head portion and an elongated trunk portion extending from the head portion are juxtaposed and connected to each other at the head portion. A polymer stent that is placed in a lumen in a state where the body is rounded and inserted into and locked in a slit formed in the head to form a ring shape, which is cylindrical as a whole. Each of the heads is inserted with the body part to form a slit in a direction substantially perpendicular to the direction of the body part, and a slit in the head part is formed on one side of the long side of each body part. At least one hook-shaped protrusion having a chevron shape having an oblique side portion on the passing side and an upright side portion locked to an end side of the slit is formed, and the hook-like protrusion portion of the body portion on the side where the hook-like protrusion portion is formed. A linear cut at the end of the slit Is formed so that the notch and the end of the slit form a claw for engaging the upright side of the hook-shaped protrusion, and the length of the slit does not include the hook-shaped protrusion of the trunk. Although the size is such that the portion can pass, it is smaller than the width from the top of the bowl-shaped projection to the opposite edge of the trunk, and the movement of the trunk in the direction of reducing the diameter of the ring is the bowl-shaped projection. The upright side portion of the portion is locked by coming into contact with the claw portion on the end side of the slit, and the movement of the body portion in the direction of expanding the ring shape is performed from the oblique side portion of the hook-shaped projection portion to the line. An auxiliary slit longer than the combined length of the slit and the linear cut portion is formed on the side of the body portion at an interval parallel to the slit in the head. Is.

  In the present invention, a plurality of T-shaped unit parts composed of a head part and an elongated body part are connected at the head part, and the body part of each unit part is rolled and inserted into the slit of the head part to form a tubular shape. In the polymer stent placed in the cavity, the portion of the trunk where the hook-shaped protrusion is provided can be elastically deformed and the width of the portion can be made variable, or the length and inclination angle of the slit of the head By making the shape, the part surrounding the slit deformable, etc., the barrel part can be inserted into the slit, and after the insertion, a ratchet function is produced in the direction of reducing the diameter of the trunk ring, and the trunk ring By making the body part movable in the slit in the diameter expansion direction, the hook-shaped protrusion is locked to the slit while the body part is inserted into the slit, and the cylindrical shape as a stent is maintained. Is Are those, never locking by the slit is deformed in the width direction the hook-shaped projections function is impaired by the tension force acting on the head, in which the ratchet feature of the stent over time is maintained.

  In addition, in the form of extending the linear cut portion on the end side of the slit, forming a claw portion and locking the hook-like projection portion of the trunk portion, an auxiliary slit parallel to the slit is formed, thereby forming a linear shape. It can prevent that the function which latches a notch part and latches a hook-shaped projection part is impaired. The polymer stent according to the present invention has a simple shape and structure and can be easily processed and manufactured, thereby reducing the time and cost required for processing and manufacturing.

1 is a developed view showing a polymer stent having a variable width portion on a body portion according to an embodiment of the present invention. (A) is a figure which shows one T-shaped unit part of the polymer stent of FIG. 1, (b) is a figure which shows the condition which rolls a trunk | drum and inserts into the slit of a head, (c) is a figure. It is a figure which shows the condition where a shape protrusion part is latched by the edge side of a slit, (d) is a figure which shows the unit part of a shape from which a width variable part differs, (e) is a variable width of another shape. It is a figure which shows the unit part which has a part. (A) is a figure which shows the unit part which has a width variable part of a different form, (b) is a figure which shows the state which the link part stood up in the width variable part of the unit part of (a). It is a figure which shows the other form of the width variable part of the unit part of Fig.3 (a). It is a figure which shows the further another form of the width variable part of the unit part of Fig.3 (a). 1 is a developed view of a polymer stent according to an embodiment of the present invention that provides a function for passing and locking a hook-like projection of a trunk in a slit of a head. (A) is a figure which shows one T-shaped unit part of the polymer stent by the expanded view of FIG. 6, (b) is a figure which shows the condition which inserts a trunk | drum to a slit, (c) is a hook-shaped protrusion. It is a figure which shows the condition where a part passes a slit. (A) is a figure which shows the T-shaped unit in which the slit of another form was formed in the head, (b) is the figure which expanded and showed the head, (c) is a hook-shaped projection part. It is a figure which shows the condition which passes a slit, (d) is a figure which shows the condition where a hook-shaped projection part is latched in the position of the restored slit. (A) is a figure which shows the T-shaped unit in which the slit of another form was formed in the head, (b) is a figure which shows a head, (c) is a hook-shaped projection part passing a slit It is a figure which shows a condition, (d) is a figure which shows the condition where a hook-shaped projection part is latched in the position of the restored slit. a) is a diagram showing a T-shaped unit in which a slit of another shape is formed in the head, (b) is a diagram showing a situation in which a hook-shaped protrusion passes through the slit, and (c) is restored. It is a figure which shows the condition where a hook-shaped projection part is latched in the position of a slit. (a) is a figure which shows the T-shaped unit in which the slit of another shape was formed in the head, (b) is a figure which expands and shows a head, (c) is a hook-shaped projection part having a slit. It is a figure which shows the condition which passes, (d) is a figure which shows the condition where a hook-shaped projection part is latched in the position of the restored slit. It is a figure which shows the T-shaped unit of the form by which the auxiliary | assistant slit was formed in the head in FIG. It is a figure which shows the T-shaped unit of the form by which the auxiliary | assistant slit was formed in the head in FIG. It is a figure which shows the T-shaped unit of the form by which the auxiliary | assistant slit was formed in the head in FIG. (A) is a figure which shows the T-shaped unit of the form by which the auxiliary | assistant slit was formed with the slit by which the nail | claw part was extended in the head, (b) is comprised by the edge part of a slit, and the linear cut | notch part. It is a figure which shows the state which the nail | claw part latched the hook-shaped projection part. The polymer stent which the slit by which the nail | claw part by the conventional technique was extended is comprised by a head part and a trunk | drum is shown with an expanded view. It is a figure which shows the state which rounded the trunk | drum of the polymer stent shown by the expanded view of FIG. 16, inserted in the slit of the head, and latched. (A) is a figure which shows one T-shaped unit of the polymer stent shown by the expanded view in FIG. 16, (b) is a figure which shows the state which the hook-shaped projection part of a trunk | drum passes the slit of a head. And (c) is a view showing a state in which the body portion of one T-shaped unit is rounded and inserted into a slit to form a ring shape. (A) is a figure which shows the state which attaches a diameter-reduced polymer stent to a balloon, and inserts it in a lumen in a cross section, (b) It is a figure shown by. It is a figure which shows the condition of the slit in the polymer stent indwelled in the lumen | bore, (a) shows the state which the linear notch part has not deform | transformed, (b) has deform | transformed so that the linear notch part may spread. It is a figure which shows a state.

  Embodiments of polymer stents according to the present invention are described below. FIG. 1 is a development view of a polymer stent according to an embodiment of the present invention. This developed view is the same as that shown in FIG. 11 in that it is a single sheet-like member in which a plurality of T-shaped unit portions composed of a head portion and a trunk portion are connected. In the development view of the polymer stent shown in FIG. 1, the polymer stent 1 is a single sheet in which a plurality of T-shaped unit portions 2 each having a head portion 3 and an elongated rectangular body portion 4 extending therefrom are connected. It is comprised as a shaped member.

  The body 4 is formed with hook-shaped projections 5 (three in each drawing in the figure) each having an oblique side and an upright side, and a slit 6 is formed on the head 3. The slit 6 has a substantially rectangular shape, the body portion 4 of each unit portion of the sheet-shaped polymer stent is rounded and the distal end portion thereof is inserted into the slit 6, and the hook-shaped projection portion 5 is locked to the end side of the slit 6. Has a ratchet function.

  As a material for forming the polymer stent 1, for example, a polyester film such as polyethylene terephthalate, a polyolefin film such as polyethylene, a polystyrene film, a fluororesin film, a bioabsorbable polymer film, or the like is used. In any case, the sheet-like material can be rounded and deformed into a cylindrical shape, and the thickness and other conditions are such that it has rigidity and elasticity to resist internal and external pressure in a cylindrical state.

  As a method for producing a polymer stent, a stent having a pattern according to a developed view can be formed by cutting out from a polymer film using a cutting plotter or the like. Although burrs are generated in the manufacturing process by this cut-out, the burrs are removed by etching using an etchant. As the etchant, for example, the one shown in Patent Document 4 is used.

FIG. 2A shows one of the T-shaped unit portions. Here, four hook-like projections 5 are formed in each unit portion 2, and each hook-like projection portion is a head portion. 3 has a hypotenuse side portion and an upright side portion on the side directed to 3. The head 3 is formed with a substantially rectangular slit 6 that is long in a direction substantially perpendicular to the longitudinal direction of the trunk, and the longitudinal length of the slit 6 is W ₁ and the lateral width is D.

  The variable width portion 7 is formed in a trapezoidal shape whose outer shape protrudes on the side opposite to the side where the bowl-shaped protrusion 5 is formed in the body portion 4, and the oblique sides on both sides are gently inclined with respect to the long side of the body portion. So that the slit 6 can be smoothly inserted. The inner part of the trapezoidal shape of the variable width portion 7 is cut into a triangle or trapezoidal shape so that the outer side portion 7a and the link portion 7b remain. In the case of the illustrated example, the inner side 7c of the cut-out portion is parallel to the outer side portion 7a, and the two sides are connected by a link portion 7b. When the force is received, the variable width portion 7 can be deformed so as to reduce the width of the body portion. When the force is not received, the width variable portion 7 is restored to its original shape by elasticity. The hook-like protrusions 5 on the opposite side are not basically deformed even when subjected to a lateral force.

The basic width of the portion of the body 4 where the hook-like protrusion 5 and the variable width portion 7 are not formed is W ₀ , and this width supports the lumen wall when the polymer stent is placed in the lumen. The width W ₀ should be as large as possible. When the width of the apex of the hook-like projections 5 to the bottom of the variable width portion 7 and W _2, so that locking is made by hook-like projections 6 after insertion of the body portion 4 into the slit 6 of the head 3 Therefore, W ₁ <W ₂ is set.

In order to ensure that the hook-like protrusion 5 is securely locked to the end side of the slit 6, the side of the width variable part 7 from the apex of the hook-like protrusion 5 from the longitudinal length W ₁ of the slit 6. it is necessary to increase the width W ₂ to the edge portion to some extent, whereas the width varying portions 7 elastically deformed hook-like projections 5 of the body 4 is in a state of reduced width are formed partially by slits The width is such that 6 can be passed.

When the barrel 2 having such a variable width portion 7 is rounded and the tip portion is inserted into the slit as shown in FIG. Insert 4 while pushing 4 downward in the figure. At this time, the variable width portion 7 is pressed against the lower side of the slit 6 and deformed inward, so that the body portion 4 is displaced downward so that the top portion of the hook-like projection portion 5 can pass through the slit 6. Become. As shown in FIG. 2 (c), when the variable width portion 7 is restored by spring elasticity, the width from the apex of the hook-shaped protrusion 5 to the bottom of the variable width portion 7 is W ₂ in the longitudinal direction of the slit 6. Since it is larger than the length W ₁ , the movement of the barrel 4 to the right (the direction of diameter reduction of the barrel ring) is locked by the contact between the upright side portion of the hook-like projection 5 and the end side of the slit 6. The The leftward movement of the body part 4 (in the diameter increasing direction of the body ring) is possible because the oblique side part of the hook-like projection part 5 is not locked to the slit 6.

In order to make it easy for the body portion 4 to pass through the slit 6, it is preferable to increase the lateral width D of the slit to some extent. When the width D of the slit 6 is greater, diagonal length of the rectangular slit is considerably longer than the longitudinal length W _1. When the body part 4 is passed through the slit 6 in a state where the body part 4 is inclined so as to be in the diagonal direction of the slit 6, the portion of the hook-shaped protrusion part 5 can be easily passed. become. In a state where the hook-shaped protrusion 5 passes through the slit 6 and is locked by the end side of the slit 6 and is left in the lumen, the body 4 is in a state along the longitudinal side of the slit 6 due to the intraluminal pressure. Locking by the hook-shaped protrusion 5 is ensured.

  In this way, by forming the variable width portion 7 that can be elastically restored on the side of the body portion 4 of each unit portion 2 that faces the hook-like projection 5, the body portion 4 of each unit portion is rounded to the head. It is easy to insert into the slit 6 and form a cylindrical stent, and the friction in the vicinity of the slit can be reduced as compared with a locking configuration in which the hook-shaped protrusion is inserted into the linear notch extending from the slit. Even if the slit is deformed to some extent at the time of expansion, the ratchet function by the hook-shaped protrusion is maintained, and the function of the stent is maintained. Reference numeral 10 denotes a joint portion as a member for connecting the body portions 4 of the plurality of unit portions. By mounting this member, the shape of the cylindrical polymer stent can be further stabilized.

  FIG. 2D shows an example of a unit portion in which the shape of the variable width portion 7 is different. In the case of FIG. 2 (a), the trapezoid inner part of the variable width portion is cut into a triangle or trapezoidal shape so that the outer side portion 7a and the linear link portion 7b remain, but FIG. 2 (d) In the variable width portion 7 shown in FIG. 1, the link portion 7b is bent in a curved shape. Also in this case, the width variable portion is elastically deformed so as to reduce the width by the pressing action from the side to the inside of the outer side portion 7.

  FIG. 2 (e) shows an example in which another mode of operation is provided as the variable width portion 7. In the variable width portion 7 of the trunk portion 4 in this example, 7a is an outer side portion, and a large number of link portions 7b bent in a square shape are provided in parallel so as to be connected to the trunk portion side. 7 d of longitudinal connection parts are formed in the form which connects the intermediate part of these. The width variable portion 7 is elastically deformable in the width direction of the body portion 4 in the same manner as in the previous case. However, in the embodiment of FIG. When the variable portion 7 passes through the slit 6, it receives a frictional force due to the contact between the side portion of the slit 6, the head 3, and the body, and particularly in the width variable portion 7 in the longitudinal connecting portion 7 d. An elastic deformation action occurs in the direction in which the width of the width variable portion decreases due to the frictional force acting to the right. As a result, the width of the body portion of the variable width portion 7 is deformed so as to be reduced, and the slit 6 passes through the portion of the hook-shaped protrusion 5.

  3 (a) and 3 (b) show examples of different forms of the width variable section 7. FIG. In FIG. 3A, the variable width portion 7 has a shape in which a linear outer side portion 7a is connected to the body portion 4 side by a large number of parallel oblique side link portions 7b, and the outer edge of the outer side portion 7a is It is substantially collinear with the lower side of the body 4. The longitudinal length of the slit 6 in the head is longer than the width from the top of the hook-like projection 5 to the lower edge of the outer side portion 7a in the trunk in this state. 4 can pass through the slit 6.

  The body 4 is rounded and inserted into the slit 6 from the tip, and the portion of the hook-shaped projection 5 passes through the slit 6 so that the body 4 of the T-shaped unit portion is ring-shaped and the slit is the outer side portion 7a of the body. In the upper position, the slit is between the front and rear hook-shaped protrusions, and the stent is locked as a cylindrical body. When the body portion 4 attempts to move in the direction of reducing the diameter of the ring shape from this state, a frictional force is generated by contact between the outer side portion 7a of the body portion and the lower end of the slit. This frictional force acts in the direction in which the oblique side link portion 7b rises, and as a result, the width variable portion 7 is in a state as shown in FIG.

At this time, the outer side portion spreads outward than in the case of FIG. 3 (a), and the width from the top of the hook-shaped projection 5 to the lower edge of the outer side portion is increased. the width corresponds to _{W 2} in FIG. 2 (a). The length of the slit 6 in the vertical direction is smaller than the width from the top of the bowl-shaped projection 5 to the lower edge of the outer side portion 7a at this time. In this state, the upright side of the bowl-shaped projection 5 is slit. Further contact (moving in the direction in which the ring of the trunk portion is reduced in diameter) is prevented at the point of contact with the end side of 6. Further, the movement of the trunk portion in the direction in which the diameter of the ring is expanded is possible because the hypotenuse portion of the bowl-shaped projection portion 5 contacts the slit 6.

  In this way, the movement of the outer side portion of the variable width portion outwardly is performed by the generation of frictional force between the lower edge portion of the outer side portion 7a and the lower end portion of the slit 6, and for this reason, the outer side portion The lower edge of the side portion 7a needs to be roughened to some extent. In the case of the polymer stent having the unit portion shown in FIGS. 3A and 3B, the function of the width variable portion 7 is that the width of the body portion 4 is changed by friction when the body portion 4 passes through the slit 6 in the head portion 3. Thus, a locking action by the hook-shaped protrusion 5 is generated, and there is a surface that is functionally different from that of the configuration shown in FIGS. 2 (a) and 2 (d).

  FIG. 4 shows a configuration of the unit portion in FIG. 3A in which a hook-like projection 7d is formed on the lower edge side of the outer side portion 7a of the variable width portion 7. FIG. This is because the hook-like protrusion 7d formed on the lower edge of the outer side portion 7a of the variable width portion 7 prevents the movement of the body ring in the direction of reducing the diameter of the trunk together with the hook-like protrusion 5, thereby expanding the ring. It acts to allow movement in the radial direction.

  FIG. 5 is a diagram in which the left end portion of the variable width portion 7 and the body portion 4 side are connected by a spring-like portion 7f as compared to the case of FIG. The link portion 7b also has a certain degree of elasticity due to the nature of the material, but by connecting it with the spring-like portion 7f, the outer edge portion 7a is further maintained in the initial state, and the frictional force with the lower end portion of the slit 6 is reliably ensured. Gives action to occur. When inserting the body portion 4 into the slit 6, the oblique link portion 7b is formed by both the action of the frictional force between the lower edge portion of the outer side portion 7a and the lower end portion of the slit 6 and the elasticity of the spring-like portion 7f. Will stand up.

  FIG. 6 shows an example of a polymer stent in the form of a ratchet mechanism different from that shown in FIGS. In the case of the polymer stent shown in FIG. 1, the variable width portion 7 is formed in the body portion 4, and in the case shown in FIG. The length of the slit 6 formed in the vertical direction can be enlarged when the body portion 4 passes, so that the ratchet mechanism acts after the hook-like projection portion 5 passes the slit 6.

  FIG. 7A shows one T-shaped unit portion 2 of the polymer stent. In the head portion 3, the slit 6 is formed in a direction substantially perpendicular to the length direction of the body portion 4. A narrow groove 6a in the lateral direction (a direction parallel to the long side of the body portion) is extended in both directions at the end of the slit 6 on the side corresponding to the side on which the protruding portion 5 is not formed. In this case, a narrow groove hole 6b having a length equal to that of the narrow groove hole 6a is formed.

  A narrow connecting portion 6c is formed between the narrow groove holes 6a and 6b, and the combined shape of the slit 6 and the narrow groove holes 6a and 6b is a substantially 〒 shape (upside down in the figure). The connecting portion 6c can be deformed so as to bend elastically downward when a force from above is applied in the drawing.

  FIG. 7B and FIG. 7C show the situation when the body 4 is rolled and inserted into the slit 6 of the head in the polymer stent having the unit portion in the form of FIG. 7A. The body 4 is inserted into the slit 6 from the tip side as shown in FIG. The width from the top of the bowl-shaped projection 5 of the trunk 4 to the opposite side edge is larger than the longitudinal length of the slit 6, and the upright side of the bowl-shaped projection 5 is the end side of the slit 6 in the insertion direction. It is locked to. From this state, when the body part 4 is pushed downward in the drawing and inserted into the slit 6, the connecting part 6 c is elastically bent downward as shown in FIG. 7C, and thereby the longitudinal direction of the slit 6. The length increases and the body 4 can pass through.

  After the trunk ring is formed, the width from the top of the bowl-shaped protrusion 5 of the trunk to the opposite side edge is larger than the longitudinal length of the slit 6 in a state where the connecting portion 6c is not deformed. The ratchet mechanism acts so that the movement of the body portion in the direction of reducing the diameter of the ring shape is locked when the upright side portion of the bowl-shaped projection portion comes into contact with the end side of the slit 6, and the body portion is The movement in the direction of expanding the ring shape passes through the oblique side portion of the hook-shaped projection and can pass while elastically deforming the connecting portion 6c.

  In FIG. 7 (a), the slit 6 and the narrow groove holes 6a and 6b are formed on the head 3 of the T-shaped unit portion to form a substantially 〒 shape. In this embodiment, the narrow groove 6b formed so as to interpose the connecting portion 6c is bent upward at, for example, both ends thereof in addition to the basic portion parallel to the narrow groove 6a as shown in FIG. You may extend so that it may have a part which goes around to the side of the narrow groove hole 6a. By including the extended portion bent as the narrow groove hole 6b in this way, the connecting portion 6c is easily bent when the body portion 4 is inserted and pressed on the lower side thereof, and the body portion is inserted into the slit. It becomes easy.

  FIG. 8A shows another example of the slit on the head, and shows one T-shaped unit portion. In this example, a peninsular tab portion 3a is formed by providing a substantially C-shaped cutout portion 6d in the head portion 3, and the slit 6 is provided in the tab portion 3a. The slit 6 is provided to be inclined with respect to a direction perpendicular to the length direction of the body portion 4. As shown in FIG. 8 (b), the width from the top of the bowl-shaped projection 5 of the trunk to the opposite edge is smaller than the length of the slit 6, but in a direction perpendicular to the longitudinal direction of the trunk. It is set larger than the projected component of the slit 6. The base of the peninsula-shaped tab portion 3a is biased to the upper side (the side on which the hook-like projection 5 is formed on the body portion 4) in the drawing, and this tab portion 3a is located on the left side (opposite to the body portion) in the drawing. The base portion is elastically bent and deformed by the action of pulling in the direction), and the slit 6 can be deformed so as to face a direction perpendicular to the longitudinal direction of the body portion.

  When the body 4 is rolled and passed through the slit 6 from the front end side, the body 4 is passed through the front end in a direction perpendicular to the inclined slit 6. When the trunk portion moves in the direction of expanding the ring shape after the ring shape of the trunk portion is formed, as shown in FIG. The base portion of the peninsular tab portion 3a is elastically deformed so that the slit 6 faces a direction perpendicular to the longitudinal direction of the trunk portion by applying a frictional force to the tab portion 3a while being in contact with the end side of the peninsula. . Thereby, the trunk portion can pass through the slit 6 in the direction of expanding the ring shape.

  As shown in FIG. 8 (d), in the state in which the body portion without the hook-shaped protrusion 5 is inserted into the slit 6, the base portion of the tab portion 3a is not elastically deformed. 6 inclines with respect to the length direction of a trunk | drum. From this state, when the body portion tries to move in the direction of reducing the diameter of the ring shape, the upright side portion of the hook-shaped projection portion 5 comes into contact with and is locked to the end side of the slit 6. Accordingly, the ratchet mechanism acts on the movement of the trunk portion in the direction of reducing the diameter of the ring shape.

  FIG. 9A shows still another example of the slit on the head, and shows one T-shaped unit portion. In this example, as shown in FIG. 9 (b), the slit 6 in the head 3 is connected as a portion 6e where the lower part (the side where the hook-like projection 5 is not provided in the body) is bent. The cut portion 6f is cut out so as to surround the bent portion 6e, and the portion in between surrounds the bent portion 6e below the slit 6 as a thin connecting portion 6g. It is a portion projecting in a peninsular shape on the side of the cut-out portion 6f.

  The length of the slit 6 combined with the bent portion 6e on the lower side is made larger than the width from the top of the flange-shaped projection 5 to the opposite edge on the body 4, and the bending in FIG. As the length projected in a direction perpendicular to the length direction of the body portion 4 in a state in which the portion is inclined with respect to the direction of the slit 6, the edge on the side facing away from the top portion of the hook-like projection portion 5 is used. It is made to become smaller than the width up to.

  When the body 4 is rounded and inserted into the slit 6, the body 4 is inserted while being pushed downward in the drawing so that the hook-shaped protrusion 5 can pass through the slit 6. At this time, when the side of the body portion 4 without the hook-like protrusion 5 pushes down the end side of the bent portion 6e, the peninsula-shaped connecting portion 6g is inclined as shown in FIG. 9C. The bent portion 6e on the lower side of the slit 6 is elastically deformed into an upright state, so that the bent portion 6e is also erected in accordance with this, and the slit 6 combined with the bent portion 6e is linear. Even as a projection component in a direction perpendicular to the length direction of the trunk portion at this time, the entire length of the slit 6 is larger than the width from the top of the bowl-shaped projection portion 5 to the edge on the opposite side. Can pass through the slit 6.

  In a portion where the hook-like protrusion 5 of the body portion 4 has passed the slit 6 and the hook-like protrusion 5 does not exist, the bent portion 6e below the slit 6 is inclined as shown in FIG. Restore to. As a result, the length of the slit 6 as a projection component in a direction perpendicular to the length direction of the trunk portion is smaller than the width from the top of the bowl-shaped protrusion 5 to the opposite side edge, and the trunk portion 4 is shown in FIG. If it is going to move rightward, the upright side portion of the hook-shaped projection 5 is locked to the upper end side of the slit 6. When the body part 4 moves to the left in the drawing, the oblique side portion of the hook-like projection part 5 is in contact with the slit 6 and the lower part (side without the hook-like protrusion part) of the trunk part is bent. By proceeding while being pressed downward, a deforming action in which the connecting portion 6g stands upright is given. Thereby, the trunk | drum 4 can move to the left in a figure. In this way, the movement of the body ring in the direction of expanding the diameter is possible, but a ratchet function is produced for the movement in the direction of reducing the diameter.

  FIG. 10A shows an example in which the slit on the head has another shape, and shows one T-shaped unit portion. The slit 6 in the head 2 has a substantially three-letter shape, and the lower part of the slit 6 (the side where the flange-like protrusion 5 is not provided in the body part) or more than that is a connecting part 6h. Surrounded by The connecting portion 6h has a shape that goes around the slit 6 in a thin band shape, and a cutout portion 6i in the head 3 is formed around the connecting portion 6h. Thus, the connecting portion 6h that goes around the lower portion of the slit 6 has a shape projecting downward in a peninsular shape at the cutout portion 6i, and this peninsular shape portion can be elastically deformed. Yes. In the state where the connecting portion 6h is not elastically deformed, the height in the vertical direction (the width direction of the trunk portion) between the upper end and the lower end of the slit 6 is on the side of the trunk portion 4 facing away from the top of the hook-like projection portion 5. The width is smaller than the width to the edge.

  FIG. 10B shows a state in which the body portion 4 is rolled up and inserted through the slit 6 of the head portion 3 from the front end side, and the body portion 4 is inserted into the slit 6 while being pushed downward in the drawing. The lower end of the slit 4 on the lower side of the body part 4 (the side facing the hook-shaped protrusion) is deformed, and the connecting part 6h that goes around the slit is deformed so that the lower end of the slit is further lowered downward. By deforming so that the height from the lower end to the lower end is enlarged, the portion of the ridge-like protrusion 5 of the trunk portion can pass through the slit 6.

  After a portion of the body portion 4 with the hook-like projection 5 passes through the slit 6, the lower portion of the connecting portion 6h that goes around the slit is restored as shown in FIG. Is smaller than the width from the apex of the hook-shaped protrusion 5 to the opposite edge, so that the body 4 from the position where the upright side portion of the hook-shaped protrusion 5 is locked to the upper end of the slit 6 in the figure. Can no longer move to the right, while the barrel 4 can be moved to the left in the figure. In this way, movement in the direction in which the ring of the trunk portion expands is possible, but a ratchet function is produced in the direction in which the diameter decreases. As the shape of the slit, the bent shape as shown in FIGS. 9A to 9D and the substantially three-letter shape as shown in FIGS. 10A to 10C have been described. Another bent slit shape such as a shape may be used.

  FIG. 11A shows still another example of the slit on the head, and shows one T-shaped unit portion. FIG. 10B shows an enlarged view of the head 3, and the connecting portion that circulates the slit 6 is a thin belt-like spring portion 6 j bent in the left and right wavy or zigzag shape in the drawing and a thin belt-like shape on the tip side. The connecting portion 6k is composed of a continuous spring portion 6j and the periphery of the connecting portion 6k is a cut-out portion 61. The spring portion 6j can be expanded and contracted in the vertical direction in the figure by elastic deformation. The inside of the connecting portion composed of the spring portion 6j and the connecting portion 6k has a width through which the body portion 4 can pass as the slit 6.

  When the connecting portion 6k is pressed downward from the inside during the passage of the body portion 4, the bent spring portion 6j is extended, the connecting portion 6k is lowered, and the length of the slit 6 is increased. The slit 6 may be only a portion surrounded by the spring portion 6j and the connecting portion 6k, but may be continuous with the upper straight portion as shown in the figure. In a state where the spring part 6j is not elastically deformed, the height from the upper end to the lower end of the spring part slit 6 is made smaller than the width from the top part of the flange-like projection part 5 to the opposite side edge in the body part 4. It is.

  FIG. 11C shows a state in which the body 4 is rolled up and inserted through the slit 6 of the head 3 from the tip side, and the body 4 is inserted into the slit 6 while being pushed downward in the drawing. When the connecting portion 6k, which is the lower end of the slit 6, is pressed downward on the lower side of the body portion 4 (the side facing the hook-shaped protrusion) and the spring portion 6j of the connecting portion that goes around the slit is deformed so as to extend, the connecting portion 6k is further lowered downward, and the height from the upper end to the lower end of the slit 6 is increased, so that the portion of the ridge-like protrusion 5 of the body portion can pass through the slit 6.

  After a portion of the body portion 4 having the hook-like protrusion 5 passes through the slit 6, the spring portion 6j of the connecting portion that goes around the slit is restored as shown in FIG. Since the height is smaller than the width from the apex of the hook-shaped protrusion 5 to the opposite edge, the body 4 is moved from the position where the upright side portion of the hook-shaped protrusion 5 is locked to the upper end of the slit 6 in the figure. While it becomes impossible to move to the right, the body 4 can be moved to the left in the figure. In this way, movement in the direction in which the ring of the trunk portion expands is possible, but a ratchet function is produced in the direction in which the diameter decreases.

  In the example of FIGS. 9 to 11, an elastically deformable thin band-shaped connecting portion surrounding the periphery of a slit that is bent in a direction intersecting the length direction of the trunk as a whole in each head of the T-shaped unit. Although formed, auxiliary slits may be formed in parallel to the bent slits formed on the respective heads. The length of the auxiliary slit is preferably longer than the longer dimension of the height from the upper end of the slit to the bottom of the cut-out portion or the height from the upper end to the lower end of the cut-out portion. By forming the auxiliary slit in this way, the stress from the trunk portion is applied to the auxiliary slit portion when moving in the direction of expanding the diameter from the balloon, and does not act on the slit portion or the like. For this reason, inconsistent deformation of the slit portion or the like that performs the ratchet function or interference with necessary deformation is suppressed, so that the ratchet function as designed is maintained, which is preferable. Such auxiliary slits may be formed when the slits and narrow grooves shown in FIG. 6 are formed so as to have a substantially square shape. The form of the T-shaped unit which formed these auxiliary slits in the head is shown in FIGS.

  Further, in the examples of FIGS. 9 to 11, a thin strip-shaped connecting portion circulates in the lower portion of the bent slit 6 and the connecting portion is elastically deformed to change the bent shape of the slit, thereby increasing the height from the upper end to the lower end of the slit. The height is changed so that the hook-like projections of the body part are passed or locked. As for the dimension example in the case of such a form, the height from the upper end to the lower end of the slit is 2.25 mm, the width is 0.25 mm, the connecting portion (spring portion) is 0.15 mm, etc. It may vary to some extent depending on conditions such as material.

  In the polymer stent of the present invention described above, a plurality of T-shaped unit parts each consisting of a head part and an elongated body part are connected to each other at the head part, and the body part of each unit part is rolled and inserted into the slit of the head part. In the polymer stent placed in the lumen as a cylindrical shape, the side of the trunk opposite to the side where the hook-shaped projection is provided can be elastically deformed, and the width of the part can be made variable, or The length of the slit on the head, the angle of inclination, the shape, the part surrounding the slit, etc. can be deformed so that the trunk can be inserted into the slit, and after insertion, the diameter of the ring of the trunk is reduced A ratchet function is generated, and the body portion is movable in the slit in the diameter increasing direction of the ring of the body portion.

  In the form of these polymer stents, a linear notch for locking the hook-like protrusion is extended at the end of the slit on the side where the hook-like protrusion is formed in the trunk, and the hooking nail In the case where the ratchet function is provided by the claw portion formed by linear cutting instead of the form of forming the portion, the claw portion does not expand and deform and the ratchet function is not impaired.

  15 (a) and 15 (b) are diagrams for preventing the claw portion from being deformed in the polymer stent in a form in which a linear cut portion extends at the end portion of the slit to form a claw portion for locking. And (a) shows a T-shaped unit in which an auxiliary slit is formed together with a slit in which a claw portion is extended at the head, and (b) is constituted by an end portion of the slit and a linear cut portion. The nail | claw part shows the state which latched the hook-shaped projection part.

  A slit 6 is formed in the head 3 in a direction substantially perpendicular to the length direction of the trunk 4, and a linear notch 6 m is formed at the end of the slit 6 on the side where the flange-shaped protrusion 5 is formed in the trunk. Is extended, and the nail | claw part which latches a hook-shaped projection part by the edge part of the slit 6, and the linear cut | notch part 6m is comprised. In the head 3, an auxiliary slit 6 n longer than the combined length of the slit 6 and the linear cut portion 6 m is formed in parallel with the slit on the right side of the slit 6 (the body 4 side). By forming this auxiliary slit 6n, even if a force in the direction of the arrow in the direction of the arrow acts on the head 3, the auxiliary slit 6 increases the width, and the claw portion expands. Is suppressed. As a result, the ratchet function can be reliably maintained even in a polymer stent having a claw portion in which a linear cut portion is extended at the end of the slit.

DESCRIPTION OF SYMBOLS 1 Polymer stent 2 T-shaped unit 3 Head 3a Tab part 4 Trunk part 5 Gutter-like projection part 6 Slit 6a Narrow groove hole 6b Narrow groove hole 6c Connection part 6d Cut part 6e Bent part 6f Cut part 6g Connection part 6h Connection part 6i Cutout part 6j Spring part 6k Connection part 6l Cutout part 6m Linear cutout part 6n Auxiliary slit 7 Width variable part 7a Outer side part 7b Link part 7c Inner side 7d Longitudinal connecting part 7e Gutter-like protrusion part 7f Spring-like part

Claims (11)

  A plurality of T-shaped unit portions each including a head portion and an elongated trunk portion extending from the head portion are arranged side by side and integrally formed so as to be connected to each other at the head portion. Is a polymer stent that is inserted into and locked in a slit formed in the head to form a ring shape, and is placed in a lumen in a tubular shape as a whole. A slit is formed in a direction substantially perpendicular to the direction of the body part, and at least one hook-shaped protrusion is formed on one side of the long side of each body part, and one side of the long side A variable width portion is formed by a link shape that can be elastically deformed so as to reduce the width of the body portion on the side facing the surface, and from the top of the flange-shaped protrusion of the body portion to the width variable portion edge on the facing side Is the vertical length of the slit in the head The hook-shaped protrusions formed on the body portions are chevron-shaped having an oblique side portion on the side passing through the slit in the head portion and an upright side portion locked to the slit, and each of the body portions. When inserting each T-shaped unit into a ring shape by rounding the head and making it a ring shape, the portion of the hook-shaped protrusion can pass through the slit by elastic deformation of the width variable portion in the trunk portion, The movement in the direction in which the trunk portion reduces the diameter of the ring shape is locked by the upright side portion of the hook-shaped protrusion contacting the end side of the slit, and the trunk portion expands the ring shape. A polymer stent characterized in that movement in the direction to be performed is possible by passing through the oblique side portion of the hook-shaped protrusion.   A plurality of T-shaped unit portions each including a head portion and an elongated trunk portion extending from the head portion are arranged side by side and integrally formed so as to be connected to each other at the head portion. Is a polymer stent that is inserted into and locked in a slit formed in the head to form a ring shape, and is placed in a lumen in a tubular shape as a whole. A slit is formed in a direction substantially perpendicular to the direction of the body part, and at least one hook-shaped protrusion is formed on one side of the long side of each body part, and one side of the long side The width-variable portion is formed by a link shape that can be elastically deformed so as to increase the width of the body portion on the side facing the body, and the hook-shaped protrusion formed on the body portion passes through the slit in the head portion. Directly locked to the hypotenuse and slit on the side And the width from the top of the hook-shaped protrusion to the opposite width variable portion edge in the state where the width variable portion of each of the body portions is not deformed. Friction with the side of the slit that is in contact with the edge of the variable width portion when the body is rounded and inserted into the slit of the head to make each T-shaped unit into a ring shape. When the width of the body portion in the variable width portion is expanded by the action, the width from the top of the hook-shaped projection to the width variable portion edge on the opposite side is larger than the longitudinal length of the slit in the head, The movement in the direction in which the body portion reduces the diameter of the ring shape is locked by the upright side portion of the hook-shaped projection portion coming into contact with the end side of the slit, and the body portion expands the diameter of the ring shape. Movement in the direction is saddle-shaped Polymer stent is characterized in that as it is possible by passing the hypotenuse portion of the raised portion.   A hook-like protrusion is formed on the outer side of the width-variable part, and the hook-like protrusion is locked with the hook-like protrusion on the opposite side of the trunk in the direction of reducing the diameter of the ring shape of the trunk. The polymer stent according to claim 2, wherein the polymer stent functions as described above.   A plurality of T-shaped unit portions each including a head portion and an elongated trunk portion extending from the head portion are arranged side by side and integrally formed so as to be connected to each other at the head portion. Is a polymer stent that is inserted into and locked in a slit formed in the head to form a ring shape, and is placed in a lumen in a tubular shape as a whole. A slit is formed in a direction substantially perpendicular to the direction of the barrel, and at least one hook-like protrusion is formed on one side of the long side of each barrel, The width from the top of the protrusion to the opposite edge is larger than the longitudinal length of the slit in the head, and the hook-shaped protrusion formed on the body portion is the hypotenuse on the side passing through the slit in the head And the upright side that is locked by the slit A slit on the side through which the edge on the side where the hook-shaped projection is not formed in the body when the body is rolled and inserted into the slit of the head in each of the heads A narrow slot extending in the direction perpendicular to the slit is extended on the end side of the slit, and another narrow slot is formed in parallel with the extended narrow slot with a thin band-shaped connecting portion therebetween. When the slits and the slits are formed to form substantially 〒-shaped through holes, each of the barrels is rounded and inserted into the slits in the head, and the barrel of the T-shaped unit is formed into a ring shape. The longitudinal length of the slit is increased by elastically bending a thin connecting portion connected to the slit by the pressing action of the edge on the side where the hook-shaped protrusion is not formed in the barrel, and the barrel Part is allowed to pass, and the body part is the ring The movement in the direction of reducing the diameter of the hook is stopped when the upright side portion of the hook-shaped protrusion comes into contact with the slit, and the movement of the trunk in the direction of expanding the ring shape is hooked. A polymer stent characterized in that it is made possible by passing from a hypotenuse part of a projection.   A plurality of T-shaped unit portions each including a head portion and an elongated trunk portion extending from the head portion are arranged side by side and integrally formed so as to be connected to each other at the head portion. Is a polymer stent that is inserted into and locked in a slit formed in the head to form a ring shape, and is placed in a lumen in a cylindrical shape as a whole, the long side of each barrel At least one hook-like protrusion is formed on one side of the head, and the hook-like protrusion formed on the trunk is an upright portion that is locked to the oblique side portion of the head passing through the slit and the slit. Each of the heads is formed with a slit having a length that allows the hook-like protrusions of the body part to pass in a direction inclined with respect to the width direction of the body part, Half of the groove around the slit And the base of the peninsula-shaped tab portion is biased toward the hook-shaped protrusion in the width direction of the trunk, so that the hypotenuse of the hook-shaped protrusion of the trunk is slit. The tab portion is elastically deformed at the base portion so that the slit inclined when passing through the tube portion faces the width direction of the trunk portion, so that the hook-like projection portion of the trunk portion can pass through the slit. When the deformation of the base of the tab portion is restored after passing through the hook-shaped protrusion, the slit is returned to the inclined direction, and the upright side portion of the hook-shaped protrusion is locked to the slit so that the body portion is The movement in the direction of reducing the diameter of the ring shape is locked, and the movement of the body portion in the direction of expanding the diameter of the ring shape is possible by passing from the hypotenuse part of the hook-shaped projection. A polymer stent characterized by that.   A plurality of T-shaped unit portions each including a head portion and an elongated trunk portion extending from the head portion are arranged side by side and integrally formed so as to be connected to each other at the head portion. Is a polymer stent that is inserted into and locked in a slit formed in the head to form a ring shape, and is placed in a lumen in a cylindrical shape as a whole, the long side of each barrel At least one hook-like protrusion is formed on one side of the head, and the hook-like protrusion formed on the trunk is an upright portion that is locked to the oblique side portion of the head passing through the slit and the slit. Each of the heads is formed with a slit having a bent shape that intersects the length direction of the body part as a whole, and a bowl-like shape is formed in the body part of the slit. No protrusion is formed The connecting part is surrounded by a thin band-like connecting part partitioned by a cut-out part so as to circulate around the part, and surrounds at least the slit part on the side where the hook-like projection part of the body part is not formed Is bent and elastically deformable, and the height from the upper end to the lower end of the slit is made smaller than the width from the top of the bowl-shaped projection to the opposite edge of the body. Each of the body portions is rounded and inserted into the slit of the head portion, and when each T-shaped unit is formed into a ring shape, the edge portion of the body portion on the side where the hook-shaped projections are not formed The shape of the bent connecting portion that presses and surrounds the lower end side of the slit is elastically deformed and stretched, so that the height from the upper end to the lower end of the slit is opposed to the top of the bowl-shaped projection of the trunk portion. Neighborhood The barrel portion can pass through the slit, and the barrel portion can move in the direction of reducing the diameter of the ring shape by contacting the upright side portion of the hook-shaped projection portion with the slit. A polymer stent characterized by being locked and capable of moving in the direction in which the trunk portion expands the ring shape by passing from the hypotenuse portion of the hook-shaped projection.   Each of the slits in the head includes a slit main part formed in a direction substantially perpendicular to the direction of the long side of the trunk part and the slit main part on the side where the hook-like projection part of the trunk part is not formed. The polymer stent according to claim 6, wherein the polymer stent is bent so as to be formed of a bent portion connected to a shape bent at the portion.   Each of the slits in the head has a substantially three-letter shape with respect to the direction of the long side of the body part, and most of the slits on the side where the hook-like projections of the body part are not formed have a thin band shape. The polymer stent according to claim 6, wherein the polymer stent is bent so as to be surrounded by the connecting portion and to protrude into a peninsular shape at a surrounding cutout portion.   The slits in each of the heads are in a direction substantially perpendicular to the long side direction of the body part, and the three sides on the side of the body part where the hook-shaped protrusions are not formed are the longitudinal direction of the slits. Characterized in that it is surrounded by a connecting portion comprising a zigzag-shaped spring portion bent on both sides and a connecting portion connecting the tip end side thereof, and has a shape projecting in a peninsular shape at a cutout portion around the connecting portion. The polymer stent according to claim 6.   An auxiliary slit in a direction longer than and parallel to the length of the slit formed in each head and parallel to the length direction of the body portion of the slit as a whole and the length of the slit and the cutout portion combined. The polymer stent according to any one of claims 4, 6 to 9, wherein is formed on each of the heads. A plurality of T-shaped unit portions each including a head portion and an elongated trunk portion extending from the head portion are arranged side by side and integrally formed so as to be connected to each other at the head portion. Is a polymer stent that is inserted into and locked in a slit formed in the head to form a ring shape, and is placed in a lumen in a tubular shape as a whole. A slit in a direction substantially perpendicular to the direction of the body portion is formed, and the oblique side portion on the side passing through the slit in the head on one side of the long side of each body portion and the end side of the slit And at least one hook-shaped protrusion having a chevron-like shape having an upright side portion that is locked to the hook, and a linear notch is formed on the end side of the slit on the side where the hook-shaped protrusion of the body is formed. Extended and the notch and the end of the slit, Further, a claw portion that locks the upright side portion of the hook-shaped protrusion is formed, and the length of the slit is a size that allows a portion without the hook-shaped protrusion of the body to pass therethrough. It is smaller than the width from the top of the ridge-shaped protrusion to the opposite edge, and the body part moves in the direction of reducing the diameter of the ring shape. It is locked by abutting, and movement of the body portion in the direction of expanding the ring shape is possible by passing the linear cut portion from the oblique side portion of the hook-shaped projection portion, and An auxiliary slit longer than the combined length of the slit and the linear cut portion is formed on the body side with an interval parallel to the slit in the portion.

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