Porous cell auxetic material, absorbable intravascular stent, preparation device and preparation method

Abstract

The invention provides a porous cell auxetic material, an absorbable intravascular stent, a preparation device and a preparation method, and belongs to the field of medical instruments, holes in porous cells are dumbbell-shaped structural holes, and the dumbbell-shaped structural holes are transversely and vertically alternately formed in the long axis direction and also transversely and vertically alternately formed in the short axis direction; dumbbell-shaped structure holes in a transverse and vertical alternating array are formed, and the short shafts of the dumbbell-shaped structure holes are provided with anti-springback inserting and pulling abutting supporting structures; the shape of the auxetic material during expansion is maintained, shrinkage is prevented when the auxetic material is axially compressed, and lasting supporting force is provided; when the vascular stent is formed by adopting the structure, radial and axial contraction of the vascular stent is prevented, the shape of the vascular stent is maintained, reliable radial supporting force is provided, the smoothness of the blood vessel is ensured, the mechanical performance of the biological absorbable stent is improved, the use amount of the biological absorbable polymer material is reduced, and the wall thickness is reduced.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a porous cell-based expandable material, an absorbable vascular stent, a preparation device, and a preparation method. Background Technology

[0002] The primary clinical treatment for severe vascular stenosis is the implantation of vascular stents to maintain vascular patency. Common types include metallic stents and biodegradable stents (bioresorbable stents). However, metallic stents, as permanent implants, can impair the normal vasodilation and vasoconstriction functions of blood vessels, and are prone to problems such as elastic recoil, intimal damage, stent thrombosis, and intimal and smooth muscle hyperplasia in later stages. Biodegradable stents are generally made of biodegradable polymer materials. Compared to metallic stents, the biggest drawback of biodegradable stents is their mechanical properties, namely poor support strength and a tendency for early elastic recoil. Therefore, to maximize the mechanical performance of biodegradable stents, current biodegradable stents have a much thicker wall than metallic stents. This leads to several problems, such as a slower endothelialization process, a higher risk of inflammation and thrombosis in the early stages of implantation, and limitations on their application in severely stenotic vessels and small blood vessels.

[0003] To address the aforementioned technical issues, CN107693854A discloses tubing for stent fabrication and its fabrication method, as well as a stent and its fabrication method. This method improves mechanical properties through a multi-layered tubing structure (outer layer, intermediate braided layer, inner layer) and claims to reduce wall thickness. The biodegradable fiber braided structure of the intermediate layer provides additional support; however, this stent exhibits a positive Poisson's ratio characteristic, which is mismatched with the negative Poisson's ratio behavior of the blood vessel itself (axial elongation during radial expansion), easily leading to problems such as inaccurate positioning and the "dog bone effect."

[0004] CN 111513900 A discloses a wave-configuration-based tensile biodegradable vascular stent structure. The wave-configuration cells extend axially synchronously during radial expansion to match vascular behavior and reduce stress concentration. However, when the structure is subjected to the radial force of vascular contraction, it undergoes radial and axial contraction, reducing the support force on the vascular vessel, reducing the support effect of the vascular stent, and in severe cases, causing failure. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to solve the problem of radial and axial contraction of vascular stents when subjected to radial force of vascular contraction. The present invention provides a porous cell-based expansible material, an absorbable vascular stent, a preparation device and a preparation method.

[0006] This invention is implemented in the following manner: A porous cell-based tensile material, wherein the pores in the porous cell-based tensile material are dumbbell-shaped pores, which are arranged alternately horizontally and vertically along the long axis and also alternately horizontally and vertically along the short axis, forming a dumbbell-shaped pore array of alternating horizontal and vertical arrangements. The short axis of the dumbbell-shaped pores is provided with an anti-rebound insertion and abutment support structure.

[0007] Preferably, the anti-rebound insertion and removal support structure includes a slot and a rod. One end of the slot is set on the wall of the dumbbell-shaped structure hole, and the other end of the slot is a groove. One end of the rod is fixed on the wall of the hole symmetrical to the support base, and the other end is a V-shaped plug. The width of the V-shaped plug is greater than the width of the groove. In the initial state, the rod is located in the slot. In the tensile state, the end of the V-shaped plug abuts against the end of the groove of the slot to form a support.

[0008] Preferably, the slot has a flared opening at one end away from the slot opening. The flared opening cooperates with the V-shaped plug. In the inserted state, the V-shaped plug is located inside the flared opening. In the uninserted state, the width of the V-shaped plug is greater than the width of the slot opening. The V-shaped plug abuts against the end of the slot to form a support.

[0009] Preferably, the absorbable vascular stent is tubular, and the long axis and short axis of the dumbbell-shaped structural pore are located on the tubular surface to form a tubular dumbbell-shaped structural pore vascular stent, and the material of the vascular stent is a bioabsorbable polymer.

[0010] Preferably, the bioabsorbable polymer comprises one or more of the following materials: polylactic acid, poly-L-lactic acid, polyglycolic acid, polylactic acid / glycolic acid copolymer, polycaprolactone, polylactic acid-caprolactone copolymer, polytrimethylene carbonate, polybutylene succinate, polyhydroxybutyrate, polyacetylglucosamine, polyoxyethylene, and polyesteramide.

[0011] The apparatus for preparing absorbable vascular stents includes a tubular extrusion die, which is composed of a mandrel and a die. The mandrel extends beyond the die outlet, and at least three concave pressure rollers with concave surfaces that mate with the mandrel surface are arranged circumferentially around the mandrel. The surfaces of the concave pressure rollers are provided with alternating horizontal and vertical arrays of dumbbell-shaped holes and forming punching dies with anti-rebound insertion and withdrawal support structures within the holes. A cooling device is provided between the die outlet and the concave pressure rollers, surrounding the mandrel.

[0012] Preferably, the diameter c of the mandrel at the die exit is greater than the diameter d of the mandrel at the concave pressure roller. That is, the mandrel is a tapered rod from the die exit to the concave pressure roller. The difference between the diameter c of the mandrel at the die exit and the diameter d of the mandrel at the concave pressure roller is equal to the total shrinkage of the extruded bioabsorbable polymer during the process from the die exit through the cooling device to the concave pressure roller to complete the curing.

[0013] A method for preparing an absorbable vascular stent, using the preparation apparatus described in claim 7, includes the following steps: 1) The bioabsorbable polymer is fed into the pipe extruder. The time and temperature parameters are set. The bioabsorbable polymer passes through the pipe extrusion die outlet of the pipe extruder to form a pipe. Since the mandrel extends out of the die outlet, the pipe is fitted onto the mandrel that extends out of the die outlet. 2) The tube moves from the die outlet through the annular spray cooling device to the concave pressure roller area. Lubricating oil is soaked on the surface of the mandrel, so that the mandrel surface and the tube are lubricated by the lubricating oil. The diameter c of the mandrel at the die outlet is greater than the diameter d of the mandrel at the concave pressure roller. That is, the mandrel is a conical rod from the die outlet to the concave pressure roller. The difference between the diameter c of the mandrel at the die outlet and the diameter d of the mandrel at the concave pressure roller is equal to the total shrinkage of the extruded bioabsorbable polymer from the die outlet through the cooling device to the concave pressure roller to complete the curing process. 3) The concave pressure roller is used to punch the tube. The forming punching die with the alternating horizontal and vertical array dumbbell-shaped holes on the surface of the concave pressure roller and the anti-rebound insertion and pulling support structure inside the holes punches the surface of the tube and washes away the lubricant to obtain the absorbable vascular stent as described in claim 4.

[0014] Compared with the prior art, the present invention has an anti-rebound insertion and abutment support structure on the short axis of the dumbbell-shaped structure hole, which maintains the shape of the tensile material when it expands, prevents it from shrinking when subjected to axial compression, and provides a lasting support force. This structure, when used to form a vascular stent, prevents the stent from contracting radially and axially when subjected to radial force due to vascular rebound, maintains the shape of the stent, provides reliable radial support, ensures vascular patency, improves the mechanical properties of bioresorbable stents, reduces the amount of bioresorbable polymer material used, and lowers the wall thickness. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an absorbable vascular stent and its deployment.

[0016] Figure 2 This is a schematic diagram of a dumbbell-shaped hole structure.

[0017] Figure 3 yes Figure 1 A magnified view of a portion of the image.

[0018] Figure 4 yes Figure 3 A schematic diagram of the anti-rebound insertion and abutment support structure.

[0019] Figure 5This is a diagram showing the expanded state of an absorbable vascular stent.

[0020] Figure 6 yes Figure 5 A magnified view of a portion of the image.

[0021] Figure 7 yes Figure 6 A schematic diagram of the anti-rebound insertion and abutment support structure.

[0022] Figure 8 This is a three-dimensional diagram of the apparatus for preparing absorbable vascular stents.

[0023] Figure 9 yes Figure 8 A longitudinal section diagram.

[0024] Figure 10 yes Figure 8 Cross-sectional view of the concave pressure roller.

[0025] Figure 11 This is a plan view of the apparatus for preparing absorbable vascular stents.

[0026] Figure 12 yes Figure 11 Enlarged view of point A in the middle.

[0027] Among them, 1 is an absorbable vascular stent; 2 is a porous cell-based tensile material; 3 is a dumbbell-shaped pore structure; 4 is the pore wall; 5 is an anti-rebound insertion and removal support structure; 51 is a slot; 511 is a groove; 512 is a flared mouth; 52 is an insertion rod; 521 is a V-shaped plug; 6 is a tubing extrusion die; 7 is a die; 71 is the die outlet; 8 is a mandrel; 81 is a concave pressure roller; 9 is a cooling device; 10 is a concave pressure roller; 11 is a bioabsorbable polymer; and 12 is a tubing. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer with the description. However, unless otherwise specified, the specific experimental methods involved in the following embodiments are conventional methods or implemented according to the conditions recommended in the manufacturer's instructions.

[0029] See Figures 1-12 A porous cell tensile material, wherein the pores in the porous cell tensile material are dumbbell-shaped structure pores 3, the dumbbell-shaped structure pores 3 are arranged alternately horizontally and vertically along the long axis and also alternately horizontally and vertically along the short axis, forming a dumbbell-shaped structure pores 3 in an alternating array of horizontal and vertical. The short axis of the dumbbell-shaped structure pores 3 is provided with an anti-rebound insertion and pulling abutment support structure 5.

[0030] like Figure 2 As shown, the major axis of the dumbbell-shaped hole 3 is axis a in the figure, and the minor axis is axis b in the figure.

[0031] The dumbbell-shaped structural hole 3 is formed by cutting around four circles, as in the dumbbell-shaped structural hole 3 formed by cutting around a positioning circle and an outer tangent circle in the tensile material disclosed in Chinese Invention Patent CN109033486A.

[0032] The material arranged by the dumbbell-shaped structural holes 3 according to the above rules is a negative Poisson's ratio tensile material. It will expand laterally when subjected to axial tension and contract laterally when subjected to axial compression, and cannot fix its expanded shape. Furthermore, an anti-rebound insertion and abutment support structure 5 is provided on the short axis of the dumbbell-shaped structural holes 3 to maintain the shape of the tensile material when it is expanded, prevent it from contracting when subjected to axial compression, and provide a lasting support force.

[0033] Furthermore, such as Figure 4 , 6 As shown, the anti-rebound insertion and removal support structure 5 includes a slot 51 and a rod 52. One end of the slot 51 is set on the hole wall 4, and the other end is a groove 511. One end of the rod 52 is fixed on the hole wall 4 symmetrical to the support base 51, and the other end is a V-shaped plug 521. The width of the V-shaped plug 521 is greater than the width of the groove 511. In the initial state, as... Figure 4 As shown, the insertion rod (52) is located in the slot (51), and in the stretched state, as... Figure 6 As shown, the V-shaped plug 521 abuts against the end of the slot 511 of the socket 51 to form a support. By resisting springback insertion and removal, it abuts against the support hole wall of the support structure 5 to prevent the dumbbell-shaped structure hole 3 from shrinking under axial compression, thus maintaining its expanded state.

[0034] Furthermore, the slot 51 has a flared opening 512 at one end away from the slot opening 511. The flared opening 512 mates with the V-shaped plug 521, and in the inserted state, such as Figure 4 As shown, the V-shaped plug 521 is located inside the flared opening 512. In the unplugged state, as... Figure 6 As shown, the width of the V-shaped plug 521 is greater than the width of the slot 511 of the slot 51, and the V-shaped plug 521 abuts against the end of the slot 51 to form a support.

[0035] like Figure 1 , 5 As shown, the absorbable vascular stent 1 prepared by the porous cell-unit stretchable material is tubular, and the long axis and short axis of the dumbbell-shaped structural pore 3 are located on the tubular surface to form a tubular dumbbell-shaped structural pore 3 vascular stent. The material of the vascular stent is a bioabsorbable polymer.

[0036] Vascular stents made of porous, extensible material expand radially and axially accordingly, conforming to the blood vessel. When the stent expands to a preset minimum value, the internal anti-rebound insertion and support structure 5 is activated. Figure 6 As shown, the V-shaped plug 521 abuts against the end of the slot 51 to form a support. At this time, the vascular stent can continue to expand until it reaches the preset maximum value.

[0037] The minimum value refers to the degree of expansion of the vascular stent when ensuring unobstructed blood flow, complete contact between the stent and the blood vessel wall, and no gaps.

[0038] The maximum value should not exceed 120% of the blood vessel diameter to avoid blood vessel damage.

[0039] Blood vessels exhibit periodic rebound contraction. Traditional vascular stents made of negative Poisson's ratio tensile materials are subjected to radial forces from the contraction of the blood vessels, causing them to contract radially and axially, thus losing their support for the blood vessels. The vascular stent of this invention introduces an anti-rebound insertion and withdrawal abutment support structure 5, which prevents the vascular stent from contracting radially and axially when subjected to radial forces, maintains the shape of the vascular stent, provides reliable radial support, and ensures the patency of the blood vessels.

[0040] Vascular stents are made of bioabsorbable polymer materials that degrade slowly, allowing blood vessels to adapt and remodel, regain elasticity, and avoid the complications associated with permanent metal stent implantation.

[0041] However, compared with metal stents, the biggest drawback of bioresorbable stents is their mechanical properties, namely poor support force and susceptibility to early elastic recoil. To maximize the mechanical performance of bioresorbable stents, the wall thickness of current bioresorbable stents is much greater than that of metal stents. This invention incorporates an anti-rebound insertion and withdrawal support structure 5 in the vascular stent, which improves the mechanical performance of the bioresorbable stent, reduces the amount of bioresorbable polymer material used, and lowers the wall thickness, making it suitable for blood vessels with severe stenosis; and also avoids early elastic recoil.

[0042] Furthermore, the bioabsorbable polymer includes one or more of the following materials: polylactic acid, poly-L-lactic acid, polyglycolic acid, polylactic acid / glycolic acid copolymer, polycaprolactone, polylactic acid-caprolactone copolymer, polytrimethylene carbonate, polybutylene succinate, polyhydroxybutyrate, polyacetylglucan, polyoxyethylene, and polyesteramide. Preferably, the selected bioabsorbable polymer is poly-L-lactic acid, etc., which are polymer materials with high crystallinity. Materials with high crystallinity can give the stent good vascular support.

[0043] The absorbable vascular stent is placed in the blood vessel by means of a balloon. When the balloon expands the vascular stent, the stent will expand radially and extend axially at the same time, so that while the stent expands radially, its axial length is greater than its original length.

[0044] like Figures 8-12 As shown, the apparatus for preparing the absorbable vascular stent includes a tubular extrusion die 6, which consists of a mandrel 8 and a die 7. The mandrel 8 extends out of the die outlet. At least three concave pressure rollers 10 with concave surfaces that mate with the surface of the mandrel 8 are arranged circumferentially around the mandrel 8. The axis of the concave pressure rollers 10 is perpendicular to the axis of the mandrel 8. The surface of the concave pressure rollers 10 is provided with a horizontal and vertical alternating array of dumbbell-shaped holes 3 and a forming punching die with an anti-rebound insertion and withdrawal support structure 5 inside the holes. A cooling device 9 is provided between the die outlet and the concave pressure rollers 10, surrounding the mandrel 8. The cooling device 9 is an annular spray device, such as CN201420775308.9, which is prior art and will not be described in detail here.

[0045] The concave pressure roller 10 can punch the bioabsorbable polymer tubing sleeved on the mandrel 8 to obtain an absorbable vascular stent 1 with a horizontal and vertical alternating array of dumbbell-shaped holes 3 and an anti-rebound insertion and withdrawal support structure 5 inside the holes.

[0046] like Figure 11 , 12 As shown, the diameter c of the mandrel 8 at the die exit 71 is greater than the diameter d of the mandrel 8 at the concave pressure roller 81. That is, the mandrel 8 is tapered from the die exit 71 to the concave pressure roller 81. The difference between the diameter c of the mandrel 8 at the die exit 71 and the diameter d of the mandrel 8 at the concave pressure roller 81 is equal to the total shrinkage of the extruded bioabsorbable polymer during the process from the die exit 71 through the cooling device 9 to the concave pressure roller 81 where it completes its curing. As the tube moves along the mandrel, it gradually cools and shrinks. The diameter of the mandrel 8 decreases synchronously from the die exit 71 to the concave pressure roller 81. The outer surface of the mandrel 8 always remains in contact with the inner surface of the tube, providing uniform support and allowing the tube to slide smoothly. This effectively avoids jamming and deformation caused by obstructed shrinkage. When the tube reaches the concave pressure roller 81, the curing of the tube is basically completed and the inner diameter is stable. The mandrel in the concave pressure roller area provides subsequent support and guidance.

[0047] The mandrel and the tube are provided with lubricating oil, which reduces friction and prevents adhesion, allowing the tube to move smoothly on the mandrel and improving product quality.

[0048] The method for preparing the absorbable vascular stent 1, using the above-mentioned preparation device, includes the following steps: 1) The bioabsorbable polymer 11 is fed into the pipe extruder, and the time and temperature parameters are set. The bioabsorbable polymer 11 passes through the pipe extrusion die 6 of the pipe extruder to form a pipe 12. Since the mandrel 8 extends out of the die outlet 71, the pipe 12 is fitted on the mandrel 8 extending out of the die outlet 71. 2) The tube moves from the die outlet 71 through the annular spray cooling device 9 towards the concave pressure roller area. Lubricating oil is soaked onto the surface of the mandrel 8, so that the surface of the mandrel 8 and the tube 12 are lubricated by the lubricating oil. The diameter c of the mandrel 8 at the die outlet 71 is greater than the diameter d of the mandrel 8 at the concave pressure roller 81. That is, the mandrel 8 is a conical rod from the die outlet 71 to the concave pressure roller 81. The difference between the diameter c of the mandrel 8 at the die outlet 71 and the diameter d of the mandrel 8 at the concave pressure roller 81 is equal to the total shrinkage of the extruded bioabsorbable polymer from the die outlet 71 through the cooling device 9 to the concave pressure roller 81 to complete the curing process. When the tube reaches the concave pressure roller 81, the curing of the tube is basically completed. 3) The concave pressure roller is used to punch the tube. The forming punching die of the alternating horizontal and vertical array dumbbell-shaped structure holes 3 on the surface of the concave pressure roller and the anti-rebound insertion and pulling support structure 5 inside the holes will punch the surface of the tube and wash away the lubricant to obtain the absorbable vascular stent 1.

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A porous cell-based tensile material, wherein the pores in the porous cell-based tensile material (2) are dumbbell-shaped structural pores (3), the dumbbell-shaped structural pores (3) are alternately arranged horizontally and vertically along the long axis and also alternately arranged horizontally and vertically along the short axis, forming a horizontally and vertically alternating array of dumbbell-shaped structural pores (3), characterized in that: The short axis of the dumbbell-shaped structure hole (3) is provided with an anti-rebound plug-in abutting support structure (5).

2. The porous cell tensile dilation material of claim 1, wherein, The anti-rebound plug-in abutting support structure (5) comprises a slot (51) and a plug-in rod (52), one end of the slot (51) is arranged on the hole wall (4) of the dumbbell-shaped structure hole (3), the other end of the slot (51) is a slot opening (511), one end of the plug-in rod (52) is fixed on the hole wall (4) symmetrical to the support seat (51), the other end of the plug-in rod (52) is a V-shaped plug (521), the width of the V-shaped plug (521) is greater than the width of the slot opening (511), in the initial state, the plug-in rod (52) is located in the slot (51), in the tension state, the end of the V-shaped plug (521) and the end of the slot opening (511) abut together to form a support.

3. The porous cell tensile dilating material of claim 2, wherein, One end of the slot (51) away from the slot opening (511) is provided with a horn mouth (512), the horn mouth (512) is matched with the V-shaped plug (521), in the plug-in state, the V-shaped plug (521) is located in the horn mouth (512), in the pull-out state, the width of the V-shaped plug (521) is greater than the width of the slot opening (511) of the slot (51), the V-shaped plug (521) and the end of the slot (51) abut together to form a support.

4. The absorbable vascular stent prepared from the porous cellular tensile material according to any one of claims 1-3, wherein, The absorbable vascular stent (1) is tubular, the long axis and the short axis of the dumbbell-shaped structure hole (3) are located on the tubular surface to form a tubular dumbbell-shaped structure hole (3) vascular stent, and the material of the vascular stent is a bioabsorbable polymer (11).

5. The absorbable vascular stent of claim 4, wherein the first and second absorbable polymer are the same. The bioabsorbable polymer comprises one or more of the following materials: polylactic acid, poly-l-lactic acid, polyglycolic acid, polylactic acid / glycolic acid copolymer, polycaprolactone, polylactic acid-caprolactone copolymer, polytrimethylene carbonate, polybutylene succinate, polyhydroxybutyrate valerate, polyacetyl glutamate, polyorthoester and polyester amide.

6. The device for preparing absorbable vascular stent according to claim 4, comprising a pipe extrusion die (6), the pipe extrusion die (6) is composed of a mandrel (8) and a die (7), characterized in that: The core rod (8) extends out of the die exit, a circumferential ring of the extended core rod (8) is provided with at least three inner concave type pressure rollers (10) matched with the surface of the core rod (8), the surface of the inner concave type pressure roller (10) is provided with a forming and cutting die mode of the dumbbell-shaped structure hole (3) and the anti-rebound plug-in abutting support structure in the hole, and a cooling device (9) surrounding the core rod (8) is arranged between the die exit and the inner concave type pressure roller.

7. The apparatus for preparing an absorbable vascular stent according to claim 6, wherein: The diameter c of the core rod (8) at the die exit (71) is greater than the diameter d of the core rod (8) at the inner concave type pressure roller (81), that is, the core rod (8) is a tapered rod from the die exit (71) to the inner concave type pressure roller (81), and the difference between the diameter c of the core rod (8) at the die exit (71) and the diameter d of the core rod (8) at the inner concave type pressure roller (81) is equal to the total shrinkage amount of the bioabsorbable polymer during the process of being extruded from the die exit (71), passing through the cooling device (9), and being solidified at the inner concave type pressure roller (81).

8. The method for preparing an absorbable vascular stent as described in claim 5, characterized in that, The preparation device of claim 7 is used to prepare the absorbable vascular stent, comprising the following steps: 1) Bioabsorbable polymer (11) is put into the pipe extruder, and time and temperature parameters are set. Bioabsorbable polymer (11) passes through the pipe extrusion die (6) of the pipe extruder to form a pipe (12). The mandrel (8) extends out of the die exit (71), and the pipe (12) is sleeved on the mandrel (8) at the die exit (71); 2) The pipe (12) moves from the die exit (71) to the inner concave roller area through the annular spray cooling device (9). The mandrel (8) surface is immersed in lubricating oil, so that the mandrel (8) surface and the pipe (12) are lubricated by the lubricating oil. The diameter c of the mandrel (8) at the die exit (71) is greater than the diameter d of the mandrel (8) at the inner concave roller (81), that is, the mandrel (8) is a tapered rod from the die exit (71) to the inner concave roller (81). The difference between the diameter c of the mandrel (8) at the die exit (71) and the diameter d of the mandrel (8) at the inner concave roller (81) is equal to the total shrinkage of the extruded bioabsorbable polymer from the die exit (71) through the cooling device (9) to the inner concave roller (81) during the solidification process; 3) The pipe (12) is punched by using the inner concave roller. The horizontally and vertically alternating array of dumbbell-shaped structure holes (3) on the surface of the inner concave roller and the shaped punching cutter die of the anti-rebound plug-in supporting structure in the holes punch the surface of the pipe (12) and wash away the lubricant to obtain the absorbable vascular stent as claimed in claim 4.

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