Closure device for closing vascular wall opening

Abstract

The invention discloses a closing device for closing an opening of a blood vessel wall, and the device comprises an anchoring part which is located in a blood vessel cavity when in use, the anchoring part is provided with a first binding surface acting with the blood vessel wall, the first binding surface at least covers the opening of the blood vessel wall, and the anchoring part is made of degradable magnesium alloy; the fixing piece is located outside the blood vessel wall when used, the fixing piece is provided with a second binding face acting on the blood vessel wall, the second binding face at least covers an opening of the blood vessel wall, and the fixing piece is made of degradable collagen; the connecting piece penetrates through the blood vessel wall opening during use, and the connecting piece is connected with the anchoring piece and the fixing piece and pulls the first binding face and the second binding face to be close to each other so as to seal the blood vessel wall opening. According to the closing device for closing the opening of the blood vessel wall, the structure and the material are improved, after implantation is completed, the closing device can be automatically degraded completely in vivo, secondary surgical removal is not needed, and injuries are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a closure device for closing an opening in a blood vessel wall. Background Art

[0002] Vascular puncture is a necessary approach for interventional surgery. Manual compression hemostasis has always been the only option for surgeons. This method requires the surgeon to continuously apply nearly blocking pressure to the vascular puncture point for 10-20 minutes and strictly restrict the patient's activities for 6-24 hours. The manual compression hemostasis method has the disadvantages of vagus nerve reflex, long hemostasis time, occupying medical staff's time, and requiring patients to stay in bed for a long time.

[0003] In recent years, devices for suturing vascular puncture sites have appeared. Vascular suturing devices use multiple sutures to tighten and knot the vascular puncture site under the skin. Although they can effectively reduce hemostasis and care time, since they use non-degradable sutures, the suture removal process may cause secondary damage to the blood vessels. In addition, vascular suturing devices have a complex structure, high cost, and a high surgical failure rate.

[0004] In view of the shortcomings of the existing technology, it is necessary to provide a blood vessel closure device to solve the problem of complex structure and the need for a second operation. Summary of the invention

[0005] Based on this, a closing device for closing a blood vessel wall opening is provided. The closing device has a simple structure and does not require secondary surgery for removal after implantation.

[0006] A closure device for closing an opening in a blood vessel wall, comprising:

[0007] An anchor, which is located in the blood vessel cavity when in use, and has a first fitting surface that acts on the blood vessel wall, the first fitting surface at least covers the blood vessel wall opening, and the anchor is made of a degradable magnesium alloy;

[0008] A fixing member, which is located outside the blood vessel wall when in use, and has a second fitting surface that interacts with the blood vessel wall, and the second fitting surface at least covers the blood vessel wall opening, and the fixing member is made of degradable collagen;

[0009] The connecting piece, when in use, penetrates the blood vessel wall opening, connects the anchoring piece and the fixing piece, and pulls the first fitting surface and the second fitting surface closer to each other to close the blood vessel wall opening.

[0010] Several optional methods are also provided below, but they are not intended to be additional limitations on the above-mentioned overall solution, but are merely further supplements or preferences. Under the premise that there are no technical or logical contradictions, each optional method can be combined with the above-mentioned overall solution separately, and multiple optional methods can also be combined.

[0011] Optionally, the anchoring member is in the shape of a sheet as a whole, and the sheet has a first surface and a second surface that are arranged opposite to each other, wherein the first surface is the first fitting surface, and the first fitting surface is a curved surface that matches the lumen of the blood vessel.

[0012] Optionally, the thickness of the anchor gradually decreases from the center to the edge of the anchor, and the thickness at the center of the anchor is not less than 1 mm, and the thickness at the edge of the anchor is not less than 0.5 mm.

[0013] Optionally, the area M1 of the first contact surface of the anchor is 25 to 100 mm 2 The area M2 of the vascular wall opening is 5 to 50 mm 2 , M1-M2≥20~50mm 2 .

[0014] Optionally, the anchor has mutually perpendicular transverse and longitudinal directions, and the longitudinal direction is parallel to the extension direction along the blood vessel wall when in use. The length L1 of the anchor in the longitudinal direction is 10 to 20 mm, and the length L2 of the anchor in the transverse direction is 3 to 8 mm, and L1-L2≥7 to 12 mm.

[0015] Optionally, the anchoring member has two groups of first through holes for penetrating the connecting member, the two groups of first through holes are respectively located on both sides of the longitudinal center line of the anchoring member, and the number of the first through holes in each group is one or two.

[0016] Optionally, the anchoring member is generally elliptical in shape, and each first through hole is located in the middle of the ellipse.

[0017] Optionally, the anchoring member has a porous structure at a portion close to the edge.

[0018] Optionally, the fixing piece is a flexible structure, and when the fixing piece is in use, the sheet structure is folded to form a multi-layer structure.

[0019] Optionally, in the magnesium alloy, the mass fraction of aluminum is 0.8% to 8%, the mass fraction of copper is 0.005% to 0.03%, and the balance is magnesium.

[0020] The present application provides a closure device for closing an opening in a blood vessel wall. Through improvements in structure and material, the closure device can be completely self-degraded in the body after implantation, eliminating the need for secondary surgery to remove it, thereby reducing damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1a to Figure 1h A schematic diagram of a process in which a closing device for closing an opening in a blood vessel wall according to the present application is introduced by a delivery device;

[0022] Figure 2a , Figure 2bA schematic diagram of a connecting member penetrating an anchoring member and a fixing member in a closing device for closing an opening in a blood vessel wall of the present application;

[0023] Figure 2c , Figure 2d A schematic diagram of a folded state of a fixing member in a closing device for closing a blood vessel wall opening of the present application;

[0024] Figure 2e , Figure 2f Schematic diagram of different ways of a connecting member penetrating a fixing member in a closing device for closing a blood vessel wall opening of the present application;

[0025] Figure 2g This is a schematic diagram of a fixing member in a delivery device in a closing device for closing an opening in a blood vessel wall according to the present application;

[0026] Figure 3a , Figure 3b , Figure 3c This is a schematic structural diagram of one embodiment of an anchoring member in a closing device for closing an opening in a blood vessel wall of the present application;

[0027] Figure 3d This is a schematic structural diagram of another embodiment of an anchoring member in a closing device for closing a blood vessel wall opening of the present application;

[0028] Figure 4a A schematic diagram of an embodiment of a fixing member in a closing device for closing an opening in a blood vessel wall of the present application;

[0029] Figure 4b A schematic diagram of another embodiment of a fixing member in the closure device for closing a blood vessel wall opening of the present application;

[0030] Figure 4c This is a schematic diagram of a fixing element loaded in a delivery device in the closure device for closing a blood vessel wall opening of the present application.

[0031] In the figure: 100, anchor; 101, first through hole; 102, first through hole; 103, second through hole; 104, first surface; 105, second surface; 106, outer edge; 107, pore structure; 108, first through hole; 109, first through hole;

[0032] 200, fixing member; 201, third through hole; 202, fourth through hole;

[0033] 300, connector; 301, knot;

[0034] 400, blood vessels;

[0035] 500. Guide wire. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] In order to better describe and illustrate the embodiments of the present application, reference may be made to one or more drawings, but the additional details or examples used to describe the drawings should not be considered as limiting the scope of the invention of the present application, any of the currently described embodiments or preferred methods.

[0038] It should be noted that when a component is referred to as being "connected" to another component, it may be directly connected to the other component or there may be a central component. When a component is referred to as being "disposed on" another component, it may be directly disposed on the other component or there may be a central component at the same time.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0040] See also Figure 1h As shown, a closure device for closing an opening in a blood vessel wall comprises:

[0041] The anchor 100 is located in the blood vessel cavity when in use. The anchor 100 has a first fitting surface that acts on the blood vessel wall. The first fitting surface at least covers the blood vessel wall opening. The anchor 100 is made of a degradable magnesium alloy.

[0042] The fixing member 200 is located outside the blood vessel wall when in use. The fixing member 200 has a second fitting surface that interacts with the blood vessel wall. The second fitting surface at least covers the blood vessel wall opening. The fixing member 200 is made of degradable collagen.

[0043] The connecting member 300 penetrates the opening of the blood vessel wall when in use. The connecting member 300 connects the anchoring member 100 and the fixing member 200 and pulls the first fitting surface and the second fitting surface closer to each other to close the opening of the blood vessel wall.

[0044] See also Figure 3a , Figure 3b , Figure 3c As shown, the anchor 100 is in the shape of a sheet as a whole, and the sheet has a first surface 104 and a second surface 105 that are arranged opposite to each other, wherein the first surface 104 is a first fitting surface, and the first fitting surface is a curved surface that matches the lumen of the blood vessel.

[0045] The outer edge 106 of the anchor 100 is a continuously extending smooth edge, and the first surface 104 and the second surface 105 are smoothly connected to the edge through arc surfaces.

[0046] The thickness of the anchor 100 gradually decreases from the center to the edge of the anchor 100 , and the thickness at the center of the anchor 100 is not less than 1 mm, and the thickness at the edge of the anchor 100 is not less than 0.5 mm.

[0047] From the center of the anchor 100 to the edge of the anchor 100, the thickness of the anchor 100 gradually decreases, so that the edge of the anchor 100 is degraded first, and the middle part interacting with the connector 300 is degraded last, ensuring that the anchor 100 will not break away from the restraint of the connector 300 before being completely degraded.

[0048] The area M1 of the first contact surface of the anchor 100 is 25 to 100 mm 2 The area of ​​the blood vessel wall opening M2 is 5 to 50 mm 2 , M1-M2≥20~50mm 2 .

[0049] The anchor 100 has mutually perpendicular transverse and longitudinal directions. When in use, the longitudinal direction is parallel to the extension direction along the blood vessel wall. The length L1 of the anchor 100 in the longitudinal direction is 10 to 20 mm, and the length L2 of the anchor 100 in the transverse direction is 3 to 8 mm. L1-L2≥7 to 12 mm.

[0050] The anchor 100 has two groups of first through holes for penetrating the connector 300 . The two groups of first through holes are respectively located on both sides of the longitudinal center line of the anchor 100 . The number of the first through holes in each group is one or two.

[0051] See also Figure 3a , Figure 3b As shown, in one embodiment, the number of each group of first through holes is two, that is, one group includes two first through holes 101, and the other group of through holes includes two first through holes 102, and the two groups of first through holes are respectively located at the longitudinal center line ( Figure 3b on both sides of the dotted line in ).

[0052] Another embodiment is shown in Figure 3d As shown, the number of each group of first through holes is one, and the first through hole 108 and the first through hole 109 are respectively located on both sides of the longitudinal center line of the anchor 100 .

[0053] A second through hole 103 matching with the guide wire 500 is provided in the middle of the anchor 100 .

[0054] See also Figure 3bAs shown, the anchor 100 is generally elliptical in shape, and each first through hole is located in the middle of the ellipse.

[0055] See also Figure 3b As shown, the anchor 100 has a pore structure 107 near the edge. The pore structure 107 can be formed by laser cutting, chemical etching, or electric spark processing.

[0056] The pore structure 107 is mainly used to accelerate the degradation of the edge of the anchor 100, so that the edge of the anchor 100 is degraded first, and the middle part interacting with the connector 300 is degraded last.

[0057] See also Figure 4a , Figure 4b As shown, the fixing member 200 is a sheet structure. The fixing member 200 is roughly in the shape of a cube, and the thickness of the fixing member 200 is 1.5-2.5 mm, the length is 20-30 mm, and the width is 8-12 mm. More preferably, the thickness of the fixing member 200 is 1.8-2.2 mm, the length is 22-24 mm, and the width is 9-10 mm.

[0058] See also Figure 2c , Figure 2d As shown, the fixing member 200 is a flexible structure, and when the fixing member 200 is used, the sheet structure is folded to form a multi-layer structure.

[0059] join Figure 4a , Figure 4b As shown, the fixing member 200 is provided with a third through hole 201 for passing the guide wire 500, and each layer of the multilayer structure of the fixing member 200 when in use is provided with a third through hole 201, and the positions of the third through holes 201 of the multilayer structure correspond to each other.

[0060] See also Figure 2c , Figure 2d As shown, when the fixing member 200 is used, the guide wire 500 simultaneously passes through the third through hole 201 in the multi-layer structure.

[0061] See also Figure 4a , Figure 4b As shown, the fixing member 200 is further provided with fourth through holes 202 for penetrating the connecting member 300 , and the fourth through holes 202 are arranged in pairs on both sides of the third through hole 201 , and the fourth through holes 202 of the multilayer structure are located in corresponding positions.

[0062] Figure 4a and Figure 4b In the embodiment, the number of the fourth through holes 202 on both sides of each third through hole 201 is different, mainly to match the different number of first through holes on the anchor 100. Figure 4a In the embodiment, each of the third through holes 201 has a fourth through hole 202 on both sides, see Figure 2cAs shown, it is used in conjunction with the anchor member 100 having two first through holes. Figure 4b In the embodiment, each of the third through holes 201 has two fourth through holes 202 on both sides, see Figure 2d As shown, it is used in conjunction with an anchor member 100 having four first through holes.

[0063] See also Figure 4c As shown, the fixing member 200 is loaded into the conveying device in the form of a rolled cylinder, and the axis direction of the cylinder is along Figure 2a The direction of the dotted line in .

[0064] See also Figure 2a , Figure 2b As shown, the connecting member 300 is a thread-like flexible member, the connecting member 300 passes through the anchoring member 100 and the fixing member 200 , and the two ends of the connecting member 300 form a closed loop through a movable knot 301 .

[0065] When in use, the fixing member 200 and the anchor member 100 are fixed to the Figure 1h Status shown.

[0066] The knot 301 is located on one side of the fixing member 200 , that is, on the outer wall of the blood vessel 400 . There is no protruding knot 301 on the anchoring member 100 , so as to avoid disturbing the blood flow in the blood vessel 400 .

[0067] Figure 2a , Figure 2b The method used to illustrate the connection member 300 passing through the anchor member 100 and the fixing member 200 is not actually present during the actual release process of the delivery device.

[0068] See also Figure 2c , Figure 2d As shown, during the release process, the fixing member 200 is folded to form a multi-layer structure. Figure 2c and Figure 2d The difference lies in the number of first through holes on the anchoring member 100 and the number of fourth through holes 202 on the fixing member 200 that are increased accordingly, and the penetration method of the connected members is also different. Figure 2d As shown, after penetrating the fixing member 200 and the anchor member 100, the connecting member 300 makes a detour at one side of the fixing member 200, and then penetrates the fixing member 200 and the anchor member 100 again in a similar manner.

[0069] See also Figure 2e , Figure 2f As shown, the connecting member 300 has different penetration modes on the fixing member 200, see Figure 2eAs shown, the connecting member 300 sequentially passes through the fourth through hole 202 on one side of the third through hole 201 on the fixing member 200, then sequentially passes through the first through hole on the anchoring member 100, and finally sequentially passes through the fourth through hole 202 on the other side of the third through hole 201 on the fixing member 200, forming a closed loop structure. Figure 2f As shown, the connecting member 300 can cross and penetrate the fourth through holes 202 on different sides of the third through hole 201 , and there is a cross point in the closed loop structure of the connecting member 300 .

[0070] The anchoring member is provided with a plurality of first through holes, the fixing member is provided with a plurality of fourth through holes, and the connecting member passes through the plurality of first through holes and the second through holes, thereby increasing the stability of the connection between the anchoring member and the fixing member.

[0071] See also Figure 2g As shown, the fixing member 200 is loaded inside the delivery device in a cylindrical manner.

[0072] The degradation time T1 of the anchor 100 is 7 to 14 days, the degradation time T2 of the fixing member 200 is 60 to 90 days, the degradation time T3 of the connecting member 300 is 30 to 90 days, T2-T1≥45 days, and T3-T1≥15 days.

[0073] The anchoring member 100, the fixing member 200 and the connecting member 300 are delivered to the opening of the blood vessel wall by a delivery device, and the delivery device can adopt existing technology.

[0074] The delivery device includes a multi-layer tube body that is coaxially arranged and can slide relative to each other in the axial direction, and a handle for operating the tube bodies to slide relative to each other. The closing device is loaded in the tube body of the delivery device. The process of using the delivery device to deliver the closing device is shown in FIG. Figure 1a to Figure 1h As shown, specifically including:

[0075] See also Figure 1a As shown, the tube body of the delivery device extends into the lumen of the blood vessel 400;

[0076] See also Figure 1b to Figure 1e As shown, the outer tube of the delivery device is withdrawn, and the anchor 100 is gradually exposed from the tube, while the tube as a whole is withdrawn until the anchor 100 is attached to the inner wall of the blood vessel 400;

[0077] See also Figure 1f As shown, the tube body of the delivery device wrapping the fixing member 200 is withdrawn, and the fixing member 200 is gradually exposed from the tube body;

[0078] See also Figure 1g As shown, the folded structure is formed by operating the tube body to squeeze the fixing member 200, and the anchoring member 100 and the fixing member 200 are respectively located on the inner and outer sides of the blood vessel wall;

[0079] See also Figure 1hBy pulling the connecting member 300, the positions of the anchor member 100 and the fixing member 200 are fixed, the anchor member 100 and the fixing member 200 are clamped on both sides of the blood vessel wall, the opening on the blood vessel wall is closed, and the delivery device is withdrawn.

[0080] The first fitting surface of the anchoring member 100 and the second fitting surface of the fixing member 200 should be at least large enough to completely cover the opening of the blood vessel wall to ensure a sealing effect.

[0081] The anchoring member 100, the fixing member 200 and the connecting member 300 are all made of degradable materials and can be completely degraded in the body after a predetermined period, without the need for further removal.

[0082] The degradation cycles of the anchor 100, the fixing member 200 and the connecting member 300 are inconsistent, and the degradation cycle of the anchor 100 is the shortest, so as to avoid the anchor 100 being free in the blood vessel 400 after the fixing member 200 and the connecting member 300 are preferentially degraded, which may bring great risks.

[0083] The degradation period of the anchor 100 is the shortest, but it cannot be too short. It must at least be ensured that the vessel wall opening is healed before degradation, otherwise the vessel wall opening will still be in a bleeding state.

[0084] The degradation of the fixing member 200 and the connecting member 300 is slower than that of the anchoring member 100, but not too slow. If it is too slow, it may cause endothelialization caused by foreign matter and affect the degradation process.

[0085] The degradation time T1 of the anchor 100 is 7 to 14 days, the degradation time T2 of the fixing member 200 is 60 to 90 days, the degradation time T3 of the connecting member 300 is 30 to 60 days, T2-T1≥45 days, and T3-T1≥15 days.

[0086] In the magnesium alloy, the mass fraction of aluminum is 0.8% to 8%, the mass fraction of copper is 0.005% to 0.03%, and the balance is magnesium.

[0087] The degradation rate of the magnesium alloy can be adjusted by adjusting the content of each component in the magnesium alloy. The degradation rate of the magnesium alloy must meet at least two indicators. First, it is slower than the healing rate of the opening of the blood vessel wall. Second, it is much faster than the degradation rate of the fixings and connecting parts.

[0088] Aluminum has a large solid solubility in solid magnesium, and its limit solid solubility is 12.7%. Aluminum can improve the castability of magnesium alloy materials and increase the strength of materials. The higher the aluminum content, the better the corrosion resistance, but the stress corrosion sensitivity increases with the increase of aluminum content.

[0089] Copper is an element that affects the corrosion resistance of magnesium alloys. When copper is added in an amount of not less than 0.05% (mass fraction), the corrosion resistance of magnesium alloys is significantly reduced.

[0090] The copper in the magnesium alloy forms a network grain boundary phase in the alloy, which acts as a cathode and can accelerate the degradation rate.

[0091] In the magnesium alloy, the mass fraction of aluminum is 0.5% to 4%, the mass fraction of copper is 0.005% to 0.02%, and the balance is magnesium.

[0092] The fixation element is made of type I collagen.

[0093] Type I collagen is a high molecular compound synthesized by animal fibroblasts. It is the most abundant and widely distributed protein in mammals and has excellent nutritional, hemostatic, biocompatibility, biodegradability and low immunogenicity.

[0094] The preparation process of type I collagen includes:

[0095] The collagen solution is freeze-dried and placed in an EDC aqueous solution, and then an NHS aqueous solution is added to adjust the pH to 5-6, and the solution is allowed to stand at 2-6°C for at least 24 hours for a cross-linking reaction, and after post-treatment, type I collagen is obtained.

[0096] EDC is 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, and NHS is N-hydroxysuccinimide.

[0097] The freeze-dried and cross-linked type I collagen can swell rapidly in PBS or saline without disintegrating, and cooperate with the anchor to block the opening of the blood vessel wall.

[0098] The collagen solution is prepared by using the existing technology, including: long-term alkali solution soaking to remove impurity proteins, long-term acid or acid enzyme solution stirring treatment, salting out, and long-term dialysis purification treatment to obtain the collagen solution.

[0099] Before freeze-drying the collagen solution, prefreeze it at -50°C for at least 6 hours. Prefreezing is used to pre-shape the collagen.

[0100] The pH was adjusted using 2-(N-morpholino)ethanesulfonic acid (also known as ethylenesulfonic acid).

[0101] The concentration of the EDC aqueous solution is 0.3-1.2 g / L.

[0102] The concentration of the EDC aqueous solution is 0.5-0.8 g / L.

[0103] The concentration of NHS aqueous solution is 0.2-0.5 g / L.

[0104] The mass ratio of NHS to EDC is 0.2-0.5:1.

[0105] The post-treatment includes: washing with 0.1 mol / L sodium hydrogen phosphate aqueous solution and pure water in sequence.

[0106] The connecting piece is a degradable suture.

[0107] The sutures are natural degradable sutures or synthetic degradable sutures.

[0108] The material of the natural degradable suture is one of catgut, collagen fiber, chitin and chitosan.

[0109] The material of the artificially synthesized degradable suture is one of polyglycolide, polylactic acid, polydioxanone, and glycolide-trimethylene carbonate copolymer.

[0110] The material of the suture is racemic polylactic acid (PLGA).

[0111] Example 1

[0112] The structure of the closing device is described above and will not be repeated here.

[0113] In magnesium alloy, the mass fraction of aluminum is 0.8%, the mass fraction of copper is 0.02%, and the balance is magnesium. The degradation rate of magnesium alloy is 0.9 mg / cm 2 ·h, the time for complete degradation of magnesium alloy is 13 days.

[0114] In this application, the characterization method of magnesium alloy degradation time is as follows:

[0115] In a 37±1℃ water bath, the weighed magnesium alloy sample was immersed in simulated body fluid (PBS) without stirring or shaking during the immersion process. After static immersion for several days, the magnesium alloy sample was taken out from the simulated body fluid, rinsed with purified water and then cleaned with ethanol, dried at room temperature and then weighed. The weight and test time were recorded, the degradation curve was drawn and the degradation time was calculated.

[0116] The magnesium alloy is surface treated, and the surface treatment process is as follows:

[0117] Phthalic acid was added to 100 mL of pure water to adjust the pH to 2.5, the weight of the added phthalic acid was recorded, and 0.03 times the weight of phthalic acid was added with fatty alcohol polyoxyethylene ether (the weight ratio of fatty alcohol polyoxyethylene ether to phthalic acid was 1:0.03), and the mixture was stirred to obtain a treatment solution, which was heated to 55° C. The magnesium alloy was immersed in the treatment solution for 90 seconds, and the magnesium alloy with the passivation film removed was obtained after vacuum drying.

[0118] The collagen uses type I collagen, and the preparation method of type I collagen is as follows:

[0119] The collagen solution was placed in a freeze dryer, first pre-frozen at -50°C for 6 hours, and then freeze-dried under vacuum for 24 hours until completely dry to obtain a collagen matrix; the collagen matrix was then placed in an EDC aqueous solution (concentration of 0.5 g / L), and then an NHS aqueous solution (concentration of 0.3 g / L) was added, the mass of NHS being 0.25 times the mass of EDC, and the pH was adjusted to 5.5 with ethylene sulfonic acid. After being placed at 4°C for 24 hours, it was washed with 0.1 mol / L disodium hydrogen phosphate and purified water, and freeze-dried to obtain type I collagen.

[0120] The time for complete degradation of collagen is 70 days.

[0121] The connecting piece is a suture, and the material of the suture is PLGA (racemic poly(lactide-glycolide) , D:L=1:1). The time for the suture to completely degrade is 40 days.

[0122] In this application, the in vitro degradation experimental process of type I collagen is as follows:

[0123] (1) Dispense the high-pressure steam-sterilized PBS buffer into several beakers. Add 100 mL of PBS buffer to each beaker. Accurately weigh collagenase (BV: 265 U / mg) and add it to the beaker containing PBS buffer. Shake well at room temperature and place in a 4°C refrigerator overnight.

[0124] Weigh the collagen and put it into the above beaker. Perform three sets of parallel tests. Take samples at certain time intervals, 1 mL each time, put them into centrifuge tubes, seal them with sealing film, and put them into a -80°C refrigerator for testing.

[0125] (2) Detection: The sample taken in step (1) is detected according to the instructions of the hydroxyproline kit to obtain the concentration of hydroxyproline in the sample. The calculation formula of hydroxyproline is: hydroxyproline concentration (μg / ml) = (absorbance of sample tube - absorbance of blank tube) / (absorbance of standard tube - absorbance of blank tube) × known concentration of standard tube.

[0126] (3) Data processing: The change in hydroxyproline concentration is converted into collagen degradation rate.

[0127] Example 2

[0128] The structure is the same as that of Example 1. In the magnesium alloy, the mass fraction of aluminum is 4%, the mass fraction of copper is 0.02%, and the balance is magnesium. The degradation rate of the magnesium alloy is 1.7 mg / cm 2 ·h, the time for complete degradation of magnesium alloy is 7 days.

[0129] Example 3

[0130] The structure is the same as that of Example 1. In the magnesium alloy, the mass fraction of aluminum is 4%, the mass fraction of copper is 0.02%, and the balance is magnesium. The degradation rate of the magnesium alloy is 1.2 mg / cm 2 ·h, the time for complete degradation of magnesium alloy is 10 days.

[0131] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0132] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A closure device for closing an opening in a blood vessel wall, characterized in that: include: An anchor, which is located in the blood vessel cavity when in use, and has a first fitting surface that acts on the blood vessel wall, the first fitting surface at least covers the blood vessel wall opening, and the anchor is made of a degradable magnesium alloy; A fixing member, which is located outside the blood vessel wall when in use, and has a second fitting surface that interacts with the blood vessel wall, and the second fitting surface at least covers the blood vessel wall opening, and the fixing member is made of degradable collagen; The connecting piece, when in use, penetrates the blood vessel wall opening, connects the anchoring piece and the fixing piece and pulls the first fitting surface and the second fitting surface closer to each other to close the blood vessel wall opening.

2. The closure device for closing a blood vessel wall opening according to claim 1, characterized in that: The anchoring component is in the shape of a sheet as a whole, and the sheet has a first surface and a second surface that are arranged opposite to each other, wherein the first surface is the first fitting surface, and the first fitting surface is a curved surface that matches the inner cavity of the blood vessel.

3. The closure device for closing a blood vessel wall opening according to claim 2, characterized in that: The thickness of the anchor gradually decreases from the center to the edge of the anchor, and the thickness at the center of the anchor is not less than 1 mm, and the thickness at the edge of the anchor is not less than 0.5 mm.

4. The closure device for sealing a blood vessel wall opening according to claim 2, characterized in that: The area M1 of the first contact surface of the anchor is 25-100 mm 2 The area M2 of the vascular wall opening is 5 to 50 mm 2 , M1-M2≥20~50mm 2 .

5. The closure device for closing a blood vessel wall opening according to claim 2, characterized in that: The anchor has mutually perpendicular transverse and longitudinal directions. When in use, the longitudinal direction is parallel to the extension direction along the blood vessel wall. The length L1 of the anchor in the longitudinal direction is 10 to 20 mm, and the length L2 of the anchor in the transverse direction is 3 to 8 mm. L1-L2≥7 to 12 mm.

6. The closure device for closing a blood vessel wall opening according to claim 5, characterized in that: The anchoring member is provided with two groups of first through holes for penetrating the connecting member, the two groups of first through holes are respectively located on both sides of the longitudinal center line of the anchoring member, and the number of the first through holes in each group is one or two.

7. The closure device for closing a blood vessel wall opening according to claim 6, characterized in that: The anchoring member is generally elliptical in shape, and each first through hole is located in the middle of the ellipse.

8. The closure device for sealing a blood vessel wall opening according to claim 2, characterized in that: The anchoring member has a porous structure at a portion close to the edge.

9. The closure device for closing a blood vessel wall opening according to claim 1, characterized in that: The fixing piece is a flexible structure, and when the fixing piece is used, the sheet structure is folded to form a multi-layer structure.

10. The closure device for closing a blood vessel wall opening according to claim 1, characterized in that: In the magnesium alloy, the mass fraction of aluminum is 0.8% to 8%, the mass fraction of copper is 0.005% to 0.03%, and the balance is magnesium.

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