Vein stent assembly and vein stent system

Abstract

The invention relates to a vein stent assembly and a vein stent system.The vein stent assembly comprises a covered stent and an annular bag, the annular bag comprises an annular bag body, a limiting piece, a protective film and a retention tube, and the vein stent assembly has a first state, a second state and a third state; the covered stent and the limiting piece are both in a radial contraction state, the annular bag body is in a contraction state, and the interior of the annular bag body is negative pressure; in the second state, the covered stent and the limiting piece are both in the radial expansion state, the annular bag body is in the contraction state, and the interior of the annular bag body is normal pressure; in the third state, the covered stent is in the radial contraction state, the limiting piece is in the radial expansion state, the annular bag body is in the expansion state, the interior of the annular bag body is in the positive pressure state, when the first state is converted into the second state, the limiting piece expands along with expansion of the covered stent, and when the second state is converted into the third state, the outer diameter of the limiting piece is kept unchanged. And the covered stent is shrunk along with the expansion of the annular bag body.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a venous stent assembly and a venous stent system. Background Art

[0002] At present, minimally invasive therapy is mainly used clinically to treat venous compression syndrome and venous stenosis or occlusion caused by venous thrombosis, mainly by implanting venous stents. The main function of stent implantation is to maintain the lumen of the blood vessel in the early stage. When the flow-limiting dissection heals or the lumen remodeling is established, the continued presence of the stent in the blood vessel becomes an unfavorable factor affecting the patency of the lumen. Common stents are metal stents and are difficult to recover. Long-term retention in the veins will cause complications such as venous thrombosis and re-occlusion of the veins. In addition, existing metal stents will damage the blood vessel wall when they are recovered and moved. Although absorbable stents can avoid the problem of long-term retention of stents, due to material properties, it is difficult to control the stability of vascular expansion and the treatment cycle. The early treatment effect is not as good as that of metal stents, and they cannot be used clinically for a certain period of time.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] The purpose of the present invention is to provide a novel recyclable venous stent assembly and a venous stent system.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] The present invention provides a venous stent assembly, which comprises a coated stent and an annular bag sleeved on the coated stent.

[0007] Specifically, the coated stent is a self-expanding hollow tubular structure with two ends open, which has a radial expansion state and a radial contraction state. The annular sac includes an annular sac body, a restriction, a protective film and a retention tube. The annular sac body is a hollow tubular structure with two ends open, and the interior thereof is a medium injection space. The annular sac body has an expansion state and a contraction state. The protective film is fixedly sleeved on the outside of the annular body, and a receiving cavity is formed between the outer surface of the annular sac body and the inner surface of the protective film. The restriction is located in the receiving cavity and is movably sleeved on the annular sac body. The restriction has a radial expansion state and a radial contraction state. The retention tube is connected to the interior of the annular sac body, and the retention tube is used to inject a medium into the interior of the annular sac body or to extract the medium from the interior of the annular sac body.

[0008] Specifically, the venous stent assembly includes a first state, a second state and a third state.

[0009] When the venous stent assembly is in the first state, the stent graft and the limiting member are both in a radially contracted state, the annular sac body is in a contracted state, and the interior of the annular sac body is under negative pressure.

[0010] When the venous stent assembly is in the second state, the stent graft and the limiting member are both in a radially expanded state, the annular sac body is in a contracted state, and the interior of the annular sac body is at normal pressure.

[0011] When the venous stent assembly is in the third state, the stent graft is in a radially contracted state, the limiting member is in a radially expanded state, the annular sac body is in an expanded state, and the interior of the annular sac body is under positive pressure.

[0012] In the embodiment of the present invention, the preset maximum outer diameter of the limiting member is substantially equal to the preset maximum outer diameter of the stent graft, and the limiting member is preset to always have a tendency to shrink inward, but the radial contraction force is less than the radial self-expansion force of the stent graft. Thus, when the venous stent assembly is converted from the first state to the second state, the limiting member expands with the expansion of the stent graft; when the venous stent assembly is converted from the second state to the third state, the outer diameter of the limiting member remains unchanged, and the stent graft shrinks with the expansion of the annular sac body.

[0013] In an embodiment of the present invention, the stent graft comprises a self-expanding stent and a graft. The self-expanding stent comprises a plurality of self-expanding stent units arranged axially and independently of each other. The graft is fixedly connected to each of the self-expanding stent units.

[0014] Furthermore, the proximal end of the self-expanding stent unit located at the proximal end of the coated stent is in an exposed state without coating, so as to facilitate its recovery by using a recovery hook at a later time.

[0015] Further, the coating includes an inner coating disposed on the inner surface of the self-expanding stent and / or an outer coating disposed on the outer surface of the self-expanding stent, and the inner coating and the outer coating are fixedly connected. Preferably, both the inner coating and the outer coating are included. The coating and the self-expanding stent are connected or the inner coating and the outer coating are connected by conventional methods in the art, including but not limited to heat fusion or bonding.

[0016] Furthermore, the self-expanding stent unit includes a wavy annular structure with wave crests and wave troughs formed in the circumferential direction.

[0017] In an embodiment of the present invention, the number of crests and troughs of each of the self-expanding stent units is equal.

[0018] In an embodiment of the present invention, the diameters of different stent units in the expanded state are equal.

[0019] In some embodiments of the present invention, the material of the self-expanding stent includes but is not limited to one or more of nickel-titanium alloy, titanium alloy, tantalum alloy, cobalt-chromium alloy, and biodegradable polymer, preferably nickel-titanium alloy, woven from nickel-titanium wire or laser-cut from nickel-titanium tube to form a "sine wave" annular structure or a multi-"V" structure with equal or different amplitudes, and is formed by conventional heat treatment, electrochemical polishing, and passivation processes.

[0020] In some embodiments of the present invention, the material of the coating includes but is not limited to one or more of expanded polytetrafluoroethylene (e-PTFE), polyethylene terephthalate (PET) or thermoplastic polyurethane (TPU).

[0021] In an embodiment of the present invention, the annular capsule extends along the axial direction of the coated stent, and the proximal portion of the coated stent is in an exposed state without coating and extending out of the proximal portion of the annular capsule.

[0022] In the embodiment of the present invention, the limiting member is a metal wire spirally wound on the annular balloon body. Because the metal wire forms a spring-like structure, it is axially compressed while radially expanding, and axially stretched while radially contracting. It has a preset maximum inner diameter, thereby limiting the maximum outer diameter of the annular balloon body when it expands in the blood vessel. The material of the metal wire is preferably nickel-titanium alloy or 316 stainless steel.

[0023] In some embodiments of the present invention, the medium is gas and / or liquid.

[0024] In some embodiments of the present invention, the annular capsule body is compliant, and the protective film is non-compliant or semi-compliant. The annular capsule body can be continuously increased with the continuous introduction of the medium, but after the outer diameter of the annular capsule reaches a preset value, the protective film will limit the increase of the outer diameter of the annular capsule body together with the limiting member, that is, the outer diameter of the annular capsule no longer continues to increase with the increase of the internal pressure of the annular capsule body or increases at a lower speed.

[0025] In the embodiment of the present invention, the material of the annular capsule body is polyvinyl chloride (PVC), latex or silicone.

[0026] In some embodiments of the present invention, the material of the protective film is polyethylene (PE), polyurethane, nylon or polyethylene terephthalate (PET).

[0027] In some embodiments of the present invention, the outer surface of the protective film is further provided with a coating to increase the thickness of the protective film, and the coating is preferably formed of liquid silicone.

[0028] In some embodiments of the present invention, since the retention tube is to be retained in the lumen of the vein, its material is preferably thermoplastic polyurethane elastomer (TPU) or silicone rubber (SiR) resistant to high pressure.

[0029] In the present invention, a positioning clamp is provided at the proximal end of the retention tube, which can not only fix the proximal end of the retention tube at the patient's access point, but also cut off the connection between the annular bag and the extracorporeal environment.

[0030] In some embodiments of the present invention, a degradable polymer coating for adhering the annular bag to the coated stent is provided between the inner surface of the annular bag and the outer surface of the coated stent. The degradable polymer coating can ensure that the coated stent and the annular bag are not separated or unloaded during the initial delivery of the venous stent assembly, and after degradation, the coated stent and the annular bag can be separated for easy separate recovery.

[0031] Furthermore, the material of the polymer coating includes but is not limited to poly(glycolic acid) copolymer (PLGA) and / or dextrorotatory polylactide (PDLA).

[0032] The present invention also provides a venous stent system, which comprises the venous stent assembly, a delivery catheter and a recovery assembly.

[0033] In some embodiments of the present invention, a cavity extending from one end to the other end is provided inside the delivery catheter, a guide tip (guide TIP) is provided at the distal end of the delivery catheter, the venous stent assembly is detachably mounted on the distal end of the delivery catheter, and the guide tip is in an exposed state extending out of the distal end of the venous stent assembly.

[0034] Furthermore, the distal end of the delivery catheter is provided with a groove sunken inward from the outer surface for accommodating the stent graft in a radially contracted state.

[0035] In some embodiments of the present invention, the retrieval component includes a retrieval catheter and a retrieval hook, the retrieval catheter is a hollow tubular structure with both ends open, the inner diameter of the retrieval catheter is larger than the outer diameter of the coated stent when it is in a radially contracted state, the retrieval hook can be movably inserted in the retrieval catheter, and the retrieval hook includes a push-pull tube extending along the length direction of the retrieval catheter, and a curved hook arranged at the distal end of the push-pull tube and capable of hooking the proximal end of the coated stent.

[0036] Furthermore, a plurality of extension rods are arranged at intervals along the circumferential direction of the distal end of the push-pull tube, and the distal end of each extension rod is provided with the hook. When the plurality of extension rods extend out of the distal end of the recovery catheter, the plurality of extension rods extend from the proximal end to the distal end gradually away from the axial direction of the push-pull tube, and the distal ends of the plurality of extension rods are on the same circle, and the diameter of the circle is roughly equal to the inner diameter of the coated stent in the radially expanded state. Each hook hooks the proximal end of the coated stent, thereby reducing the risk of the coated stent falling off during the recovery process.

[0037] In some embodiments of the present invention, 3 to 6 extension rods are evenly spaced to ensure stability and balance during recovery.

[0038] In some embodiments of the present invention, the venous stent system further comprises an injection device and a suction device. The injection device is used to inject a medium into the annular sac body, and the suction device is used to extract the medium from the annular sac body.

[0039] In an embodiment of the present invention, the injection device and the suction device are connected to the retention tube via a two-way connector with a valve and a Luer connector, respectively.

[0040] In the embodiment of the present invention, the medium is air, the injection device may be a pressure pump, and the suction device may be a negative pressure device.

[0041] In some embodiments of the present invention, the venous stent system further comprises a guide wire.

[0042] In some embodiments of the present invention, the venous stent system further comprises a protective sheath, and the protective sheath is removably sleeved on the venous stent assembly.

[0043] The assembly method of some components of the venous stent system of this embodiment before leaving the factory is as follows: put the annular bag under normal pressure on the coated stent, then put the coated stent on the delivery catheter, use a suction device to adjust the inside of the annular bag body to a negative pressure state (the negative pressure is not less than 0.0001atm), the venous stent assembly is adjusted to the first state, use a positioning clamp to clamp the retention tube or use other methods (such as tightening with a cable tie, tying a knot, connecting a Luer connector, etc.) to disconnect the connection between the inside of the annular bag body and the external environment, and put on a protective sheath.

[0044] The method of using the venous stent system of the present invention is generally as follows:

[0045] (1) The protective sheath is removed, and the coated stent and the annular balloon at the distal end of the delivery catheter are delivered to the lesion site via the guide wire into the venous blood vessel. During this process, the venous stent assembly is always in the first state due to the negative pressure inside the annular balloon body and the action of the limiter.

[0046] (2) The interior of the annular sac body is connected to the external environment through the retention tube, the annular sac body is converted to a normal pressure state, the coated stent self-expands, the restriction member radially expands accordingly, and the venous stent assembly is converted to the second state.

[0047] (3) The delivery catheter is withdrawn and the retention tube is positioned at the patient's access site using a positioning clamp. The implantation of the venous stent assembly is complete.

[0048] (4) When the venous stent assembly needs to be retrieved, the delivery catheter is inserted into the lesion site through the guide wire, the distal end of the delivery catheter passes through the venous stent assembly, and the retrieval assembly is inserted along the delivery catheter. The push-pull tube is pushed so that the curved hook extends out of the retrieval catheter and hooks the proximal end of the coated stent.

[0049] (5) A positive pressure (the positive pressure does not exceed 12 atm) is provided to the internal delivery medium of the annular sac body through the injection device, so that the annular sac body expands, compresses the stent graft inward, and withdraws the retrieval hook to withdraw the stent graft into the retrieval catheter.

[0050] (6) Use a suction device to adjust the inside of the annular sac body to a negative pressure state again (the negative pressure is not less than 0.0001 atm). When the annular sac body contracts, the limiter contracts radially until the annular sac contracts and fits tightly against the delivery catheter, maintaining the negative pressure state and connecting to the recovery assembly to be withdrawn from the body.

[0051] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0052] The venous stent assembly of the present invention allows short-term implantation (ranging from several weeks to several months) to maintain or restore patency of venous blood flow, and can be promptly removed after the veins have recovered. The venous stent assembly of the present invention not only has a good supporting effect on the vascular lesion site and high stability, but also does not cause damage to the blood vessel wall during recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 It is a schematic diagram of the local structure of the venous stent system of Example 1 in a blood vessel (before the venous stent assembly is deployed);

[0055] Figure 2 for Figure 1 A partial perspective view of

[0056] Figure 3It is a schematic diagram of the local structure of the venous stent system of Example 1 in a blood vessel (after the venous stent assembly is deployed);

[0057] Figure 4 for Figure 3 A partial perspective view of

[0058] Figure 5 This is a schematic diagram of the structure of the venous stent assembly in Example 1 before deployment (the retention tube is hidden);

[0059] Figure 6 for Figure 5 The enlarged view of point A in the middle;

[0060] Figure 7 for Figure 5 perspective drawing;

[0061] Figure 8 for Figure 7 The enlarged view of point B in the middle;

[0062] Fig. 9 This is a schematic diagram of the structure of the venous stent assembly after deployment in Example 1 (the retention tube is hidden);

[0063] Fig.10 for Fig. 9 Enlarged view of point C in the middle;

[0064] Fig.11 for Fig. 9 perspective drawing;

[0065] Fig.12 for Fig. 9 A cross-sectional view of

[0066] Fig.13 is a schematic diagram of the front view of the annular sac in Example 1 when in an expanded state;

[0067] Fig.14 is a schematic side view of the structure of the annular sac in Example 1 in an expanded state;

[0068] Fig.15 This is a schematic diagram of the structure of the venous stent system of Example 1 after some components are assembled;

[0069] Fig.16 It is a schematic diagram of the structure of the recycling component in Example 1;

[0070] Fig.17 for Fig.16 perspective drawing;

[0071] Fig.18 for Fig.16 Side view of

[0072] Fig.19This is a schematic diagram of the distal structure of the venous stent system of Example 1 in a venous vessel (before the venous stent assembly is deployed);

[0073] Fig. 20 for Fig.19 Schematic diagram of the structure of the mid-vein stent assembly after deployment;

[0074] Fig.21 for Fig. 20 Schematic diagram of the structure after the delivery catheter is withdrawn;

[0075] Fig. 22 Schematic diagram of the distal structure of the venous stent system of Example 1 in a venous vessel (the recovery component hooks the deployed venous stent component);

[0076] Fig.23 for Fig. 22 Schematic diagram of the structure of the stent graft after contraction;

[0077] Fig.24 for Fig.23 A partial perspective view of

[0078] Fig.25 for Fig.23 Schematic diagram of the structure in which the covered stent is partially withdrawn into the retrieval catheter;

[0079] Fig.26 for Fig.25 A partial perspective view of

[0080] Fig. 27 for Fig.25 Schematic diagram of the structure after the covered stent is completely withdrawn into the retrieval catheter and the annular balloon is contracted.

[0081] In the above figure: 11, coated stent; 111, self-expanding stent; 112, coating; 12, annular bladder; 121, annular bladder body; 122, limiting member; 123, protective film; 124, retention tube; 13, delivery catheter; 131, guide tip; 141, retrieval catheter; 1421, push-pull tube; 1422, extension rod; 1423, hook; 15, protective sheath; 161, positioning clip; 162, Luer connector; 7, blood vessel wall. DETAILED DESCRIPTION

[0082] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0083] In the description of the present invention, it is necessary to understand that the distal end refers to the end of the instrument or component away from the operator, and the proximal end refers to the end of the instrument or component close to the operator; the axial direction refers to the direction parallel to the line connecting the distal and proximal centers of the instrument or component, and the radial direction refers to the direction perpendicular to the axial direction; the inner and outer are positions defined by the distance relative to the center of the instrument or component, wherein the inner is a position close to the center of the instrument or component, and the outer is a position far from the center of the instrument or component. The description of the above-mentioned directional words is only for the convenience of describing the embodiments of the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0084] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0085] In the description of the present invention, a plurality refers to two or more.

[0086] In the description of the present invention, "normal pressure" refers to a standard atmospheric pressure, which is approximately 101 kPa or 1.01 bar. "Negative pressure" refers to a pressure state lower than normal pressure. When the inside of the annular sac body is at negative pressure, the internal pressure is lower than the external environmental pressure. "Positive pressure" refers to a pressure state higher than normal pressure. When the inside of the annular sac body is at positive pressure, the internal pressure is higher than the external environmental pressure.

[0087] The degradable material described in the present invention refers to a material that can be completely degraded in the body within one to fifteen days.

[0088] The short-term retention of the central venous catheter in the tube body provides a basis for the feasibility of the short-term retention of the retention tube in the venous stent assembly of the present invention. The central venous port catheter remains implanted from several months to several years.

[0089] The disclosure below provides many different implementations or examples to implement different structures of the embodiments of the present invention. In order to simplify the disclosure of the embodiments of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the embodiments of the present invention.

[0090] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0091] Example 1

[0092] This embodiment provides a venous stent system, which includes a venous stent assembly, a delivery catheter 13 and a recovery assembly.

[0093] Specifically, Figures 1 to 14As shown, the venous stent assembly includes a coated stent 11 and an annular bag 12 sleeved on the coated stent 11. In this embodiment, the coated stent 11 is a self-expanding hollow tubular structure with open ends, which has a radial expansion state and a radial contraction state. The coated stent 11 includes a self-expanding stent 111 and a coating 112. The self-expanding stent 111 includes a plurality of self-expanding stent units arranged axially and independently of each other. The coating 112 is fixedly connected to each self-expanding stent unit, and the proximal end of the self-expanding stent unit located at the proximal end of the coated stent 11 is in an exposed state without a coating, so as to facilitate the use of a recovery hook to recover it later. In this embodiment, the coating 112 includes an inner coating arranged on the inner surface of the self-expanding stent 111 and an outer coating arranged on the outer surface of the self-expanding stent 111. The inner coating and the outer coating are fixedly connected. In other embodiments, only the inner coating or the outer coating may be provided. In this embodiment, the inner coating and the outer coating are connected together by hot melting to form a "sandwich" structure with the self-expanding stent 111 sandwiched therein. In this embodiment,. In this embodiment, the self-expanding stent unit includes a wavy annular structure with crests and troughs formed in the circumferential direction, the number of crests and troughs of each self-expanding stent unit is equal, and the diameters of different stent units in the deployed state are equal. In this embodiment, the self-expanding stent 111 is formed by laser cutting and conventional heat treatment, electrochemical polishing, and passivation processes of a nickel-titanium alloy tube. The material of the coating 112 is expanded polytetrafluoroethylene. In this embodiment, the annular capsule 12 extends along the axial direction of the coated stent 11, and the proximal end of the coated stent 11 is in a bare state without coating and extending out of the proximal end of the annular capsule 12. The annular sac 12 includes an annular sac body 121, a limiting member 122, a protective film 123 and a retention tube 124. The annular sac body 121 is a hollow tubular structure with both ends open, and the interior of the annular sac body 121 is a medium injection space. The annular sac body 121 has an expanded state and a contracted state. The protective film 123 is fixedly sleeved on the outside of the annular body. An accommodating cavity is formed between the outer surface of the annular sac body 121 and the inner surface of the protective film 123. The limiting member 122 is located in the accommodating cavity and is movably sleeved on the annular sac body 121. The limiting member 122 has a radial expansion state and a radial contraction state. The retention tube 124 is connected to the interior of the annular sac body 121, and the retention tube 124 is used to inject the medium into the interior of the annular sac body 121 or to extract the medium from the interior of the annular sac body 121. In this embodiment, the limiting member 122 is a metal wire spirally wound on the annular sac body 121. Because the metal wire forms a spring-like structure, it is axially compressed while expanding radially and axially stretched while contracting radially. It has a preset maximum inner diameter, and can thereby limit the maximum outer diameter of the annular sac body 121 when it expands in the blood vessel. The material of the metal wire in this embodiment is nickel-titanium alloy.In this embodiment, the annular capsule body 121 is compliant and made of polyvinyl chloride, and the protective film 123 is non-compliant or semi-compliant and made of polyethylene. The annular capsule body 121 can be continuously increased as the medium is continuously introduced, but after the outer diameter of the annular capsule 12 reaches a preset value, the protective film 123 will limit the increase of the outer diameter of the annular capsule body 121 together with the limiting member 122, so that the outer diameter of the annular capsule 12 no longer continues to increase or increases at a lower rate as the internal pressure of the annular capsule body 121 increases. In this embodiment, the outer surface of the protective film 123 is also provided with a coating to increase the thickness of the protective film 123, and the coating is preferably formed of liquid silicone. In this embodiment, the material of the retention tube 124 is a high-pressure resistant thermoplastic polyurethane elastomer. In this embodiment, a positioning clip 161 is provided at the proximal end of the retention tube 124, which can not only fix the proximal end of the retention tube 124 at the patient's access, but also cut off the connection between the annular capsule 12 and the extracorporeal environment. In this embodiment, a degradable polymer coating is provided between the inner surface of the annular capsule 12 and the outer surface of the coated stent 11 for adhering the annular capsule 12 to the coated stent 11. The degradable polymer coating can ensure that the coated stent 11 and the annular capsule 12 are not separated or unloaded during the early delivery of the intravenous stent assembly, and after degradation, the coated stent 11 and the annular capsule 12 can be separated for easy separate recovery. The material of the polymer coating in this embodiment is glycolic acid copolymer.

[0094] Specifically, Fig.15 As shown, the delivery catheter 13 has a cavity extending from one end to the other end, and a guide tip 131 is provided at the distal end of the delivery catheter 13. The venous stent assembly is detachably sleeved on the distal end of the delivery catheter 13, and the guide tip is in an exposed state extending out of the distal end of the venous stent assembly. In this embodiment, the distal end of the delivery catheter 13 is provided with a groove that is recessed inward from the outer surface, for accommodating the coated stent 11 in a radially contracted state.

[0095] Specifically, Figures 16 to 18As shown, the recovery component includes a recovery catheter 141 and a recovery hook. The recovery catheter 141 is a hollow tubular structure with both ends open. The inner diameter of the recovery catheter 141 is larger than the outer diameter of the coated stent 11 when it is in a radially contracted state. The recovery hook can be movably inserted in the recovery catheter 141. The recovery hook includes a push-pull tube 1421 extending along the length direction of the recovery catheter 141, and a curved hook 1423 arranged at the distal end of the push-pull tube 1421 and capable of hooking the proximal end of the coated stent 11. In this embodiment, four extension rods 1422 are evenly spaced along the circumferential direction of the distal end of the push-pull tube 1421, and a hook 1423 is provided at the distal end of each extension rod 1422. When the extension rod 1422 extends out of the distal end of the recovery catheter 141, each extension rod 1422 extends from the proximal end to the distal end gradually away from the axial direction of the push-pull tube 1421. The distal ends of the four extension rods 1422 are on the same circle, and the diameter of the circle is roughly equal to the inner diameter of the coated stent 11 in the radially expanded state. Each hook 1423 hooks the proximal end of the coated stent 11, thereby reducing the risk of the coated stent 11 falling off during the recovery process.

[0096] Specifically, the venous stent system further includes an injection device, a suction device, a guide wire and a protective sheath 15. In this embodiment, the medium is air, the injection device is a pressure pump connected to the retention tube 124 through a two-way connector with a valve and a Luer connector 162, and the suction device is a negative pressure device connected to the retention tube 124 through a two-way connector with a valve and a Luer connector 162. In this embodiment, the protective sheath 15 is removably sleeved on the venous stent assembly before deployment.

[0097] The assembly method of some components of the venous stent system of this embodiment before leaving the factory is as follows: the annular bag 12 under normal pressure is put on the coated stent 11, and then the coated stent 11 is put on the delivery catheter 13, and the interior of the annular bag body 121 is adjusted to a negative pressure state (the negative pressure is not less than 0.0001atm) using a suction device, and the venous stent assembly is adjusted to the first state, and the retention tube 124 is clamped using the positioning clamp 161 or other methods (such as tightening with a cable tie, tying a knot, connecting a Luer connector 162, etc.) are used to disconnect the connection between the interior of the annular bag body 121 and the external environment, and then the protective sheath 15 is put on.

[0098] In this embodiment, the venous stent assembly includes a first state, a second state, and a third state. When the venous stent assembly is in the first state, the stent graft 11 and the limiting member 122 are both in a radially contracted state, the annular sac body 121 is in a contracted state, and the interior of the annular sac body 121 is at negative pressure. When the venous stent assembly is in the second state, the stent graft 11 and the limiting member 122 are both in a radially expanded state, the annular sac body 121 is in a contracted state, and the interior of the annular sac body 121 is at normal pressure. When the venous stent assembly is in the third state, the stent graft 11 is in a radially contracted state, the limiting member 122 is in a radially expanded state, the annular sac body 121 is in an expanded state, and the interior of the annular sac body 121 is at positive pressure.

[0099] like Figures 19 to 27 As shown, the method of using the venous stent system of this embodiment is roughly as follows:

[0100] (1) Remove the protective sheath 15, and deliver the coated stent 11 and the annular balloon 12 at the distal end of the delivery catheter 13 to the lesion site through the guide wire into the venous blood vessel. During this process, under the negative pressure inside the annular balloon body 121 and the action of the limiter, the venous stent assembly is always in the first state.

[0101] (2) The interior of the annular sac body 121 is connected to the external environment through the retention tube 124, the annular sac body 121 is converted to a normal pressure state, the coated stent 11 expands by itself, and the limiting member 122 expands radially accordingly, and the venous stent assembly is converted to the second state.

[0102] (3) The delivery catheter 13 is withdrawn, and the retention tube 124 is positioned at the patient's access point using the positioning clamp 161. The implantation of the venous stent assembly is completed, and the venous stent assembly is closely attached to the blood vessel wall 7.

[0103] (4) When the venous stent assembly needs to be recovered, the delivery catheter 13 is introduced to the lesion site through the guide wire, the distal end of the delivery catheter 13 passes through the venous stent assembly, and the recovery assembly is introduced along the delivery catheter 13. The push-pull tube 1421 is pushed so that the curved hook 1423 extends out of the recovery catheter 141 and hooks the proximal end of the coated stent 11.

[0104] (5) Provide positive pressure (positive pressure not exceeding 12 atm) to the internal delivery medium of the annular sac body 121 through the injection device, so that the annular sac body 121 expands, compresses the coated stent 11 inward, and withdraws the retrieval hook to withdraw the coated stent 11 into the retrieval catheter 141.

[0105] (6) Use a suction device to adjust the inside of the annular sac body 121 to a negative pressure state again (the negative pressure is not less than 0.0001 atm). When the annular sac body 121 contracts, the limiter contracts radially until the annular sac 12 contracts and is tightly attached to the delivery catheter 13, maintaining the negative pressure state and connecting the recovery component to be withdrawn from the body together.

[0106] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A venous stent assembly, characterized in that: The venous stent assembly comprises a coated stent (11) and an annular bag (12) sleeved on the coated stent (11). The stent graft (11) is a self-expanding hollow tubular structure with both ends open, and has a radial expansion state and a radial contraction state. The annular capsule (12) comprises an annular capsule body (121), a limiting member (122), a protective film (123) and a retention tube (124). The annular capsule body (121) is a hollow tubular structure with two ends open, and the interior of the annular capsule body is a medium injection space. The annular capsule body (121) has an expansion state and a contraction state. The protective film (123) is fixedly sleeved on the outside of the annular capsule body. An accommodating cavity is formed between the outer surface of the annular capsule body (121) and the inner surface of the protective film (123). The limiting member (122) is located in the accommodating cavity and is movably sleeved on the annular capsule body (121). The limiting member (122) has a radial expansion state and a radial contraction state. The retention tube (124) is connected to the interior of the annular capsule body (121). The retention tube (124) is used to inject medium into the interior of the annular capsule body (121) or to extract the medium from the interior of the annular capsule body (121). The venous stent assembly includes a first state, a second state and a third state, When the venous stent assembly is in the first state, the stent graft (11) and the limiting member (122) are both in a radially contracted state, the annular sac body (121) is in a contracted state, and the interior of the annular sac body (121) is in a negative pressure; When the venous stent assembly is in the second state, the stent graft (11) and the limiting member (122) are both in a radially expanded state, the annular sac body (121) is in a contracted state, and the interior of the annular sac body (121) is at normal pressure; When the venous stent assembly is in the third state, the stent graft (11) is in a radially contracted state, the limiting member (122) is in a radially expanded state, the annular sac body (121) is in an expanded state, and the interior of the annular sac body (121) is in a positive pressure state. When the venous stent assembly is converted from the first state to the second state, the limiting member (122) expands along with the expansion of the coated stent (11); When the venous stent assembly is transformed from the second state to the third state, the outer diameter of the limiting member (122) remains unchanged, and the coated stent (11) contracts as the annular sac body (121) expands.

2. The venous stent assembly according to claim 1, characterized in that: The coated stent (11) comprises a self-expanding stent (111) and a coating (112); the self-expanding stent (111) comprises a plurality of self-expanding stent units arranged axially and independently of each other; the coating (112) is fixedly connected to each of the self-expanding stent units.

3. The venous stent assembly according to claim 2, characterized in that: The proximal end of the self-expanding stent unit located at the proximal end of the coated stent (11) is in an exposed state without coating.

4. The venous stent assembly according to claim 2, characterized in that: The coating (112) includes an inner coating arranged on the inner surface of the self-expanding stent (111) and / or an outer coating arranged on the outer surface of the self-expanding stent (111), and the inner coating and the outer coating are fixedly connected.

5. The venous stent assembly according to claim 2, characterized in that: The self-expanding stent unit includes a wavy circular ring structure with crests and troughs formed in the circumferential direction; and / or, the material of the self-expanding stent (111) is one or more of nickel-titanium alloy, titanium alloy, tantalum alloy, cobalt-chromium alloy, and biodegradable polymer; and / or, the material of the coating (112) is one or more of expanded polytetrafluoroethylene, polyethylene terephthalate, or thermoplastic polyurethane elastomer.

6. The venous stent assembly according to claim 1, characterized in that: The annular capsule (12) extends along the axial direction of the coated stent (11), and the proximal end of the coated stent (11) is in an exposed state without coating and extending out of the proximal end of the annular capsule (12).

7. The venous stent assembly according to claim 1, characterized in that: The limiting member (122) is a metal wire spirally wound on the annular sac body (121), and / or the medium is gas and / or liquid.

8. The venous stent assembly according to claim 1, characterized in that: The annular sac body (121) is compliant, and the protective film (123) is non-compliant or semi-compliant; and / or, the annular sac body (121) is made of polyvinyl chloride, latex or silicone, and the protective film (123) is made of polyethylene, polyurethane, nylon or polyethylene terephthalate; and / or, the outer surface of the protective film (123) is provided with a silicone coating; and / or, the retention tube (124) is made of thermoplastic polyurethane elastomer or silicone rubber.

9. The venous stent assembly according to claim 1, characterized in that: A degradable polymer coating for adhering the annular capsule (12) to the coated stent (11) is provided between the inner surface of the annular capsule (12) and the outer surface of the coated stent (11).

10. The venous stent assembly according to claim 9, characterized in that: The material of the polymer coating is glycolic acid copolymer and / or dextrorotatory polylactide.

11. A venous stent system, characterized in that: The venous stent system comprises the venous stent assembly according to any one of claims 1 to 10, a delivery catheter (13) and a retrieval assembly.

12. The venous stent system according to claim 11, characterized in that: The delivery catheter (13) has a cavity extending from one end to the other end thereof, and the distal end of the delivery catheter (13) is provided with a guide tip (131). The venous stent assembly is detachably sleeved on the distal end of the delivery catheter (13), and the guide tip (131) is in an exposed state extending out of the distal end of the venous stent assembly.

13. The venous stent system according to claim 11, characterized in that: The retrieval component includes a retrieval catheter (141) and a retrieval hook. The retrieval catheter (141) is a hollow tubular structure with both ends open. The inner diameter of the retrieval catheter (141) is larger than the outer diameter of the coated stent (11) when it is in a radially contracted state. The retrieval hook can be movably inserted in the retrieval catheter (141). The retrieval hook includes a push-pull tube (1421) extending along the length direction of the retrieval catheter (141), and a curved hook (1423) arranged at the distal end of the push-pull tube (1421) and capable of hooking the proximal end of the coated stent (11). The push-pull tube (1421) is a hollow tubular structure with both ends open. The inner diameter of the push-pull tube (1421) is larger than the outer diameter of the delivery catheter (13).

14. The venous stent system according to claim 13, characterized in that: A plurality of extension rods (1422) are arranged at intervals in the circumferential direction of the distal end of the push-pull tube (1421), and a hook (1423) is provided at the distal end of each extension rod (1422). When the plurality of extension rods (1422) extend out of the distal end of the recovery catheter (141), the plurality of extension rods (1422) extend from the proximal end to the distal end, gradually away from the axial direction of the push-pull tube (1421).

15. The venous stent system according to claim 11, characterized in that: The venous stent system further includes an injection device and a suction device; and / or, the venous stent system further includes a guide wire; and / or, the venous stent system further includes a protective sheath (15), and the protective sheath (15) is removably mounted on the venous stent assembly.

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