A venous stent assembly and a venous stent system

Abstract

The present application relates to a kind of venous stent assembly and venous stent system, the venous stent assembly includes covered stent and annular capsule, annular capsule includes annular capsule body, restriction, protective film and retention tube, venous stent assembly includes first state, second state and third state, in first state, covered stent and restriction are all radial contraction state, annular capsule body is contraction state, annular capsule body inside is negative pressure;In second state, covered stent and restriction are all radial expansion state, annular capsule body is contraction state, annular capsule body inside is normal pressure;In third state, covered stent is radial contraction state, restriction is radial expansion state, annular capsule body is inflation state, annular capsule body inside is positive pressure, by first state to second state conversion, restriction expands along with the expansion of covered stent, by second state to third state conversion, the outer diameter of restriction remains unchanged, covered stent shrinks along with the inflation of annular capsule body.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a venous stent assembly and a venous stent system. BACKGROUND

[0002] Currently, minimally invasive therapy is mainly used in the clinical treatment of venous compression syndrome and venous stenosis or occlusion caused by venous thrombosis, mainly by implanting a venous stent. The main role of the stent after implantation is to maintain the early blood vessel lumen, and when the flow-limiting dissection heals or the lumen remodeling is established, the continuous existence 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, and long-term retention in the venous blood vessel can cause complications such as venous thrombosis and venous occlusion again, and the existing metal stent can cause damage to the blood vessel wall when it is recovered and moved. The absorbable stent can avoid the problem of long-term retention of the stent, but due to the reasons of material performance, the stability of blood vessel expansion and the treatment period are difficult to control, and the early treatment effect is not as good as that of the metal stent, and it cannot be used in the clinic within a certain period of time.

[0003] In view of this, the present application is proposed. SUMMARY

[0004] The purpose of the present application is to provide a new type of recoverable venous stent assembly and venous stent system.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0006] The present application provides a venous stent assembly, which comprises a covered stent and an annular capsule sleeved on the covered stent.

[0007] Specifically, the covered stent is a self-expanding hollow tubular structure with open ends, which has a radial expansion state and a radial contraction state. The annular capsule comprises an annular capsule body, a limiting member, a protective film and a retention tube, the annular capsule body is a hollow tubular structure with open ends, the inside of which is a medium injection space, the annular capsule body has an expansion state and a contraction state, the protective film is fixedly sleeved on the outside of the annular body, a containing cavity is formed between the outer surface of the annular capsule body and the inner surface of the protective film, the limiting member is located in the containing cavity and movably sleeved on the annular capsule body, the limiting member has a radial expansion state and a radial contraction state, the retention tube is in communication with the inside of the annular capsule body, and the retention tube is used for injecting medium into the inside of the annular capsule body or removing the medium in the inside of the annular capsule body.

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

[0009] When the venous stent assembly is in the first state, the covered stent and the restriction member are in a radially contracted state, the toroidal balloon body is in a contracted state, and the interior of the toroidal balloon body is under negative pressure.

[0010] When the venous stent assembly is in the second state, the covered stent and the restriction member are in a radially expanded state, the toroidal balloon body is in a contracted state, and the interior of the toroidal balloon body is under normal pressure.

[0011] When the venous stent assembly is in the third state, the covered stent is in a radially contracted state, the restriction member is in a radially expanded state, the toroidal balloon body is in an inflated state, and the interior of the toroidal balloon body is under positive pressure.

[0012] In the embodiment of the present application, the maximum outer diameter of the restriction member is substantially equal to the maximum outer diameter of the covered stent, and the restriction member is preset to always have a tendency to contract inward, but the radial contraction force is less than the radial self-expanding expansion force of the covered stent. Thus, when the venous stent assembly is converted from the first state to the second state, the restriction member expands with the expansion of the covered stent; when the venous stent assembly is converted from the second state to the third state, the outer diameter of the restriction member remains unchanged, and the covered stent contracts with the inflation of the toroidal balloon body.

[0013] In the embodiment of the present application, the covered stent comprises a self-expanding stent and a covering film, the self-expanding stent comprises a plurality of self-expanding stent units arranged in an axial direction and independently disposed, and the covering film is fixedly connected with each self-expanding stent unit.

[0014] Further, the proximal end portion of the self-expanding stent unit at the proximal end of the covered stent is in a bare state without the covering film, facilitating the use of a recovery hook for recovery in the later stage.

[0015] Further, the covering film comprises an inner covering film arranged on the inner surface of the self-expanding stent and / or an outer covering film arranged on the outer surface of the self-expanding stent, and the inner covering film and the outer covering film are fixedly connected. Preferably, both the inner covering film and the outer covering film are included. The connection method of the covering film and the self-expanding stent or the connection method of the inner covering film and the outer covering film can adopt conventional methods in the art, including but not limited to heat welding or adhesion.

[0016] Further, the self-expanding stent unit comprises a wave-shaped circular ring structure with wave crests and wave troughs in the circumferential direction.

[0017] In the embodiment of the present application, the number of wave crests and wave troughs of each self-expanding stent unit is equal.

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

[0019] In some embodiments of the present application, the material of the self-expandable stent comprises one or more of, but not limited to, nickel-titanium alloy, titanium alloy, tantalum alloy, cobalt-chromium alloy, biodegradable polymer, preferably nickel-titanium alloy, which is woven by nickel-titanium wire or cut into a "positive wave" by laser cutting from a nickel-titanium tube into a ring structure with equal amplitude or different amplitude or a multi-"V" structure, and is shaped by conventional heat treatment, electrochemical polishing and passivation process.

[0020] In some embodiments of the present application, the material of the covering film comprises one or more of, but not limited to, expanded polytetrafluoroethylene (e-PTFE), polyethylene terephthalate (PET) or thermoplastic polyurethane elastomer (TPU).

[0021] In embodiments of the present application, the annular capsule extends along the axial direction of the covered stent, and the proximal end of the covered stent is in a bare state without covering and protruding from the proximal end of the annular capsule.

[0022] In embodiments of the present application, the limiting member is a metal wire spirally wound on the annular capsule body, which forms a spring-like structure that is compressed axially while being radially expanded, and is stretched axially while being radially contracted, and has a preset maximum inner diameter, thereby being able to limit the maximum outer diameter of the annular capsule body when it is expanded 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 application, the medium is gas and / or liquid.

[0024] In some embodiments of the present application, the annular capsule body is compliant, and the protective film is non-compliant or semi-compliant. The annular capsule body can continuously increase with the continuous input of the medium, but the protective film will limit the increase of the outer diameter of the annular capsule body together with the limiting member when the outer diameter of the annular capsule reaches a preset value, i.e. the outer diameter of the annular capsule will no longer continue to increase or the increasing speed will be smaller with the increase of the internal pressure of the annular capsule body.

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

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

[0027] In some embodiments of the present application, 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 application, the material of the retention tube is preferably a high-pressure resistant thermoplastic polyurethane elastomer (TPU) or silicone rubber (SiR) as the retention tube is to be retained in the lumen of the vein.

[0029] In the present application, the proximal end of the retention tube is provided with a positioning clamp, which can not only fix the proximal end of the retention tube at the patient access, but also cut off the communication between the annular sac and the extracorporeal environment.

[0030] In some embodiments of the present application, a degradable high-molecular coating layer for bonding the annular sac and the covered stent is arranged between the inner surface of the annular sac and the outer surface of the covered stent. The degradable high-molecular coating layer can ensure that the covered stent and the annular sac are not separated and unloaded during the early delivery of the venous stent assembly, and after the degradation of the degradable high-molecular coating layer, the covered stent and the annular sac can be separated for easy separation and recovery.

[0031] Further, the material of the high-molecular coating layer includes but is not limited to polyglycolic acid copolymer (PLGA) and / or poly-D-lactide (PDLA).

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

[0033] In some embodiments of the present application, a lumen extending from one end to the other end of the delivery catheter is arranged in the interior of the delivery catheter, a guide tip (guide TIP) is arranged at the distal end of the delivery catheter, the venous stent assembly is detachably sleeved on the distal end of the delivery catheter, and the guide tip is in a bare state protruding from the distal end of the venous stent assembly.

[0034] Further, a groove recessed inward from the outer surface is arranged at the distal end of the delivery catheter, which is used to accommodate the covered stent in the radially contracted state.

[0035] In some embodiments of the present application, the recovery assembly comprises a recovery catheter and a recovery hook, the recovery catheter is a hollow tubular structure with both ends open, the inner diameter of the recovery catheter is greater than the outer diameter of the covered stent in the radially contracted state, the recovery hook is movably inserted into the recovery catheter, and the recovery hook comprises a push-pull tube extending along the length direction of the recovery catheter and a hook arranged at the distal end of the push-pull tube, which can hook the proximal end of the covered stent.

[0036] Further, a plurality of extension rods are arranged along the circumferential direction of the distal end of the push-pull tube, and the distal end of each of the extension rods 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 gradually extend away from the axis direction of the push-pull tube from the proximal end to the distal end, the distal end of the plurality of extension rods is on the same circle, and the diameter of the circle is substantially equal to the inner diameter of the covered stent in the radial expansion state, and each hook hooks the proximal end of the covered stent, thereby reducing the risk of falling off during the recovery of the covered stent.

[0037] In some embodiments of the present application, 3-6 extension rods are uniformly arranged to ensure stability and balance during recovery.

[0038] In some embodiments of the present application, the intravenous stent system further comprises an injection device and a suction device. The injection device is used to inject a medium into the annular capsule body, and the suction device is used to suck the medium in the annular capsule body.

[0039] In an embodiment of the present application, the injection device and the suction device are connected to the retention tube through two-way joints with valves and luer joints, respectively.

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

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

[0042] In some embodiments of the present application, the intravenous stent system further comprises a protective sheath, which is removably sleeved on the intravenous stent assembly.

[0043] The assembly method of the intravenous stent system of the present embodiment before leaving the factory is as follows: the annular capsule in normal pressure state is sleeved on the covered stent, then the covered stent is sleeved on the delivery catheter, the suction device is used to adjust the inside of the annular capsule body to a negative pressure state (the negative pressure is not less than 0.0001 atm), the intravenous stent assembly is adjusted to the first state, the positioning clamp is used to clamp the retention tube or the communication between the inside and the outside of the annular capsule body is disconnected by other ways (such as tightening with a strap, knotting, connecting a luer joint, etc.), and then the protective sheath is sleeved.

[0044] The use method of the intravenous stent system of the present application is as follows:

[0045] (1) The protective sheath is removed, the delivery catheter is guided into the intravenous blood vessel through the guide wire, and the covered stent and the annular capsule at the distal end of the delivery catheter are sent to the lesion site, during which, under the action of the negative pressure in the inside of the annular capsule body and the action of the limiting member, the intravenous stent assembly is always in the first state.

[0046] (2) The inside of the annular capsule body is communicated with the outside environment through the retention tube, the annular capsule body is converted to a normal pressure state, the covered stent is self-inflated and expanded, the limiting member is radially expanded, and the venous stent assembly is converted to a second state.

[0047] (3) The delivery catheter is withdrawn, the retention tube is positioned at the patient access using a positioning clip, and the implantation of the venous stent assembly is completed.

[0048] (4) When the venous stent assembly needs to be recovered, a delivery catheter is sent to the lesion site through a guide wire, the distal end of the delivery catheter passes through the venous stent assembly, a recovery assembly is sent along the delivery catheter, and the push-pull tube is pushed to make the hook extend out of the recovery catheter and hook the proximal end of the covered stent.

[0049] (5) A medium is supplied to the inside of the annular capsule body through an injection device to provide a positive pressure (the positive pressure is not more than 12 atm), the annular capsule body is inflated, the covered stent is compressed inward, and the covered stent is withdrawn into the recovery catheter by the recovery hook.

[0050] (6) The inside of the annular capsule body is adjusted to a negative pressure state again (the negative pressure is not less than 0.0001 atm) using a suction device, the limiting member is radially retracted to the annular capsule when the annular capsule body is retracted, the limiting member is tightly attached to the delivery catheter, the negative pressure state is maintained, and the recovery assembly is withdrawn out of the body together.

[0051] Thanks to the above technical solutions, the present application has the following advantages compared with the prior art:

[0052] The venous stent assembly of the present application allows short-term implantation (from several weeks to several months), is used to maintain or restore the patency of venous blood flow, and can be removed in time after the venous blood vessel recovers. The venous stent assembly of the present application not only has good support effect on the vascular lesion site and high stability, but also does not cause damage to the blood vessel wall when recovered. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

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

[0055] Figure 2 A local perspective view of Figure 1 ;

[0056] Figure 3Schematic view of the local structure of the venous stent system of Example 1 in a blood vessel (after deployment of the venous stent assembly);

[0057] Figure 4 is a perspective view of Figure 3 ;

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

[0059] Figure 6 is a perspective view of Figure 5 ;

[0060] Figure 7 is a perspective view of Figure 5 ;

[0061] Figure 8 is a perspective view of Figure 7 ;

[0062] Figure 9 is a schematic view of the structure of the venous stent assembly of Example 1 after deployment (with the retention tube hidden);

[0063] Figure 10 is a perspective view of Figure 9 ;

[0064] Figure 11 is a perspective view of Figure 9 ;

[0065] Figure 12 is a cross-sectional view of Figure 9 ;

[0066] Figure 13 is a schematic view of the front structure of the torus capsule of Example 1 in the inflated state;

[0067] Figure 14 is a schematic view of the side structure of the torus capsule of Example 1 in the inflated state;

[0068] Figure 15 is a schematic view of the structure of the venous stent system of Example 1 after assembly of the partial components;

[0069] Figure 16 is a schematic view of the structure of the recovery assembly of Example 1;

[0070] Figure 17 is a perspective view of Figure 16 ;

[0071] Figure 18 is a side view of Figure 16 ;

[0072] Figure 19Structure of the venous stent system of Example 1 in a venous vessel (before the venous stent assembly is deployed);

[0073] Figure 20 For Figure 19 Structure of the venous stent system of Example 1 in a venous vessel (after the venous stent assembly is deployed);

[0074] Figure 21 For Figure 20 Structure of the venous stent system of Example 1 in a venous vessel (after the venous stent assembly is deployed);

[0075] Figure 22 Structure of the venous stent system of Example 1 in a venous vessel (the retrieval assembly hooks the deployed venous stent assembly);

[0076] Figure 23 For Figure 22 Structure of the venous stent system of Example 1 in a venous vessel (after the venous stent assembly is deployed);

[0077] Figure 24 For Figure 23 Partial perspective view of the stent graft of Example 1;

[0078] Figure 25 For Figure 23 Structure of the venous stent system of Example 1 in a venous vessel (after the venous stent assembly is deployed);

[0079] Figure 26 For Figure 25 Partial perspective view of the stent graft of Example 1;

[0080] Figure 27 For Figure 25 Structure of the venous stent system of Example 1 in a venous vessel (after the venous stent assembly is deployed);

[0081] In the above figures: 11, stent graft; 111, self-expandable stent; 112, graft covering; 12, annular capsule; 121, annular capsule body, 122, restriction; 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 fitting; 7, vessel wall. DETAILED DESCRIPTION

[0082] In the following, only certain exemplary embodiments are simply described. As those skilled in the art will recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of embodiments of the present application. Therefore, the drawings and description are to be regarded as illustrative in nature and not as restrictive.

[0083] In the description of the present application, it needs to be understood that the distal end refers to the end of the instrument or component far away from the operator, 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 center line connecting the distal end and the proximal end of the instrument or component, the radial direction refers to the direction perpendicular to the axial direction; the inner and outer are defined as the position relative to the center of the instrument or component, wherein the inner is the position close to the center of the instrument or component, and the outer is the position away from the center of the instrument or component. The above orientation words are only for the convenience of describing the embodiments of the present application and simplifying the description, and are not intended to 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 application.

[0084] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "fixed" and the like should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or can be integrated. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0085] In the description of the present application, multiple refers to two or more.

[0086] In the description of the present application, "normal pressure" refers to one standard atmosphere, and the standard atmosphere is about 101kPa or 1.01bar. "Negative pressure" refers to a pressure state lower than normal pressure, when the inside of the annular capsule body is under negative pressure, the internal pressure is less than the external environmental pressure. "Positive pressure" refers to a pressure state higher than normal pressure, when the inside of the annular capsule body is under positive pressure, the internal pressure is greater than the external environmental pressure.

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

[0088] The short-term retention of central venous cannulation to the tube body provides the feasibility of the short-term retention of the retention tube in the intracorporeal venous stent assembly, and the central venous port catheter is kept implanted for several months to several years.

[0089] The following disclosure provides many different embodiments or examples for implementing different structures of the embodiments of the present application. In order to simplify the disclosure of the embodiments of the present application, the components 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 application.

[0090] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0091] Embodiment 1

[0092] The present embodiment provides a venous stent system, which comprises a venous stent assembly, a delivery catheter 13 and a recovery assembly.

[0093] In particular, as Figures 1 to 14As shown, the venous stent assembly comprises a covered stent 11 and an annular capsule 12 sleeved on the covered stent 11. In the embodiment, the covered stent 11 is a self-expanding hollow tubular structure with open ends, which has a radially expanded state and a radially contracted state. The covered stent 11 comprises a self-expanding stent 111 and a covering 112, the self-expanding stent 111 comprises a plurality of self-expanding stent units arranged in the axial direction and independently arranged, and the covering 112 is fixedly connected with each self-expanding stent unit. The proximal end of the self-expanding stent unit at the proximal end of the covered stent 11 is in a bare state without covering, which is convenient for later recovery by a recovery hook. In the embodiment, the covering 112 comprises an inner covering arranged on the inner surface of the self-expanding stent 111 and an outer covering arranged on the outer surface of the self-expanding stent 111, and the inner covering and the outer covering are fixedly connected. In other embodiments, only the inner covering or the outer covering can be arranged. In the embodiment, the inner covering and the outer covering are connected together by heat melting, and form a "sandwich" structure with the self-expanding stent 111 clamped therebetween. In the embodiment, the self-expanding stent unit comprises a wave-shaped circular ring structure forming wave crests and wave troughs in the circumferential direction, the number of wave crests and wave troughs of each self-expanding stent unit is equal, and the diameters of different stent units in the expanded state are equal. In the embodiment, the self-expanding stent 111 is formed by laser cutting of a nickel-titanium alloy pipe and conventional heat treatment, electrochemical polishing and passivation process. The material of the covering 112 is expanded polytetrafluoroethylene. In the embodiment, the annular capsule 12 extends along the axial direction of the covered stent 11, and the proximal end of the covered stent 11 is in a bare state without covering and protruding from the proximal end of the annular capsule 12. 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 open ends, the inside of which is a medium injection space. The annular capsule body 121 has an expanded state and a contracted state. The protective film 123 is fixedly sleeved on the outside of the annular body, and a containing 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 containing cavity and movably sleeved on the annular capsule body 121. The limiting member 122 has a radially expanded state and a radially contracted state. The retention tube 124 communicates with the inside of the annular capsule body 121, and is used for injecting medium into the inside of the annular capsule body 121 or extracting the medium in the inside of the annular capsule body 121. In the embodiment, the limiting member 122 is a metal wire spirally wound on the annular capsule body 121. The metal wire forms a spring-like structure, which is axially compressed while radially expanded, and is axially stretched while radially contracted. The metal wire has a preset maximum inner diameter, thereby being able to limit the maximum outer diameter of the annular capsule body 121 when it is expanded in the blood vessel. The material of the metal wire in the embodiment is nickel-titanium alloy.In the embodiment, the annular capsule body 121 is compliant, and is made of polyvinyl chloride; the protective film 123 is non-compliant or semi-compliant, and is made of polyethylene; the annular capsule body 121 can continuously increase with the continuous input of the medium, but the protective film 123, together with the limiting member 122, limits the increase of the outer diameter of the annular capsule body 121 when the outer diameter of the annular capsule 12 reaches the preset value, so that the outer diameter of the annular capsule 12 no longer continuously increases or increases at a smaller speed with the increase of the internal pressure of the annular capsule body 121. In the embodiment, the outer surface of the protective film 123 is further provided with a coating to increase the thickness of the protective film 123, and the coating is preferably formed of liquid silicone. In the embodiment, the material of the retention tube 124 is high-pressure-resistant thermoplastic polyurethane elastomer. In the embodiment, the proximal end of the retention tube 124 is provided with a positioning clamp 161, which can not only fix the proximal end of the retention tube 124 at the patient access, but also cut off the communication between the annular capsule 12 and the external environment. In the embodiment, a degradable high-molecular coating for bonding the annular capsule 12 and the covered stent 11 is arranged between the inner surface of the annular capsule 12 and the outer surface of the covered stent 11, which can ensure that the covered stent 11 and the annular capsule 12 are not separated and unloaded during the early delivery of the venous stent assembly, and can be separated after the degradation of the degradable high-molecular coating, so as to facilitate the separate recovery. In the embodiment, the material of the high-molecular coating is hydroxyacetic acid copolymer.

[0094] Specifically, as shown in Figure 15 , the inside of the delivery catheter 13 is provided with a lumen extending from one end to the other end, 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 is in a bare state protruding from the distal end of the venous stent assembly. In the embodiment, the distal end of the delivery catheter 13 is provided with a groove recessed inward from the outer surface, for accommodating the covered stent 11 in the radially contracted state.

[0095] Specifically, as shown in Figures 16 to 18As shown, the recovery assembly includes a recovery conduit 141 and a recovery hook, the recovery conduit 141 is a hollow tubular structure with both ends open, the inner diameter of the recovery conduit 141 is greater than the outer diameter of the covered stent 11 in the radial contraction state, the recovery hook is movably inserted in the recovery conduit 141, the recovery hook includes a push-pull tube 1421 extending along the length direction of the recovery conduit 141, and a hook 1423 capable of hooking the proximal end of the covered stent 11 arranged at the distal end of the push-pull tube 1421. In this embodiment, four extension rods 1422 uniformly distributed in the circumferential direction of the distal end of the push-pull tube 1421 are arranged, and the distal end of each extension rod 1422 is respectively provided with a hook 1423. When the extension rod 1422 extends out of the distal end of the recovery conduit 141, each extension rod 1422 respectively extends away from the axis direction of the push-pull tube 1421 from the proximal end to the distal end, the distal ends of the four extension rods 1422 are on the same circle, and the diameter of the circle is substantially equal to the inner diameter of the covered stent 11 in the radial expansion state, and each hook 1423 hooks the proximal end of the covered stent 11, thereby reducing the risk of falling off during the recovery of the covered stent 11.

[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 part of the venous stent system of this embodiment before leaving the factory is: sleeving the annular capsule 12 in normal pressure state on the covered stent 11, then sleeving the covered stent 11 on the delivery conduit 13, adjusting the inside of the annular capsule body 121 to a negative pressure state (the negative pressure is not less than 0.0001 atm) using the suction device, adjusting the venous stent assembly to the first state, disconnecting the communication between the inside of the annular capsule body 121 and the outside environment by using the positioning clamp 161 to clamp the retention tube 124 or by other ways (such as tightening with a strap, knotting, connecting a luer connector 162, etc.), and sleeving the protective sheath 15.

[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 covered stent 11 and the limiting member 122 are both in a radially contracted state, the annular capsule body 121 is in a contracted state, and the interior of the annular capsule body 121 is under negative pressure. When the venous stent assembly is in the second state, the covered stent 11 and the limiting member 122 are both in a radially expanded state, the annular capsule body 121 is in a contracted state, and the interior of the annular capsule body 121 is under normal pressure. When the venous stent assembly is in the third state, the covered stent 11 is in a radially contracted state, the limiting member 122 is in a radially expanded state, the annular capsule body 121 is in an inflated state, and the interior of the annular capsule body 121 is under positive pressure.

[0099] As shown in FIG. 1, the method of using the venous stent system of this embodiment is as follows: Figures 19 to 27

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

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

[0102] (3) Withdraw the delivery catheter 13, and use the positioning clip 161 to position the retention tube 124 at the patient's access. The implantation of the venous stent assembly is completed, and the venous stent assembly is tightly attached to the vessel wall 7.

[0103] (4) When it is necessary to recover the venous stent assembly, guide the delivery catheter 13 into the lesion site through the guide wire, and the distal end of the delivery catheter 13 passes through the venous stent assembly. The retrieval assembly is sent along the delivery catheter 13, the push-pull tube 1421 is pushed to make the hook 1423 extend out of the retrieval catheter 141 and hook the proximal end of the covered stent 11.

[0104] (5) Deliver a medium to the interior of the annular capsule body 121 through the injection device to provide positive pressure (the positive pressure is not more than 12 atm) to make the annular capsule body 121 inflate and compress the covered stent 11 inward. The covered stent 11 is withdrawn into the retrieval catheter 141 by the retrieval hook.

[0105] ​(6) using the suction device to adjust the inside of the annular capsule body 121 to a negative pressure state again (the negative pressure is not less than 0.0001 atm), the annular capsule body 121 shrinks, and the limiting member shrinks radially to the annular capsule 12 to be closely attached to the delivery conduit 13, the negative pressure state is maintained and withdrawn from the body together with the recovery assembly.

[0106] The preferred embodiments of the present application have been described above with the aid of drawing only for the purpose of illustration, and the present application is not limited to these preferred embodiments. Changes in form and detail can be made to the application without departing from the spirit of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An intravenous stent assembly, characterized by: The venous stent assembly comprises a covered stent (11) and an annular capsule (12) sleeved on the covered stent (11), The covered stent (11) is a self-expanding hollow tubular structure with open ends, which has a radially expanded state and a radially contracted 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 open ends, the inside of which is a medium injection space, the annular capsule body (121) has an expanded state and a contracted state, the protective film (123) is fixedly sleeved on the outside of the annular capsule body (121), a containing 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 containing cavity and movably sleeved on the annular capsule body (121), the limiting member (122) has a radially expanded state and a radially contracted state, the retention tube (124) is in communication with the inside of the annular capsule body (121), and the retention tube (124) is used for injecting medium into the inside of the annular capsule body (121) or extracting medium from the inside of the annular capsule body (121), The annular capsule (12) extends along the axial direction of the covered stent (11), The limiting member (122) is a metal wire spirally wound on the annular capsule body (121), A degradable high-molecular coating for bonding the annular capsule (12) and the covered stent (11) is arranged between the inner surface of the annular capsule (12) and the outer surface of the covered stent (11), The venous stent assembly comprises a first state, a second state and a third state, When the venous stent assembly is in the first state, the covered stent (11) and the limiting member (122) are both in a radially contracted state, the annular capsule body (121) is in a contracted state, and the inside of the annular capsule body (121) is under negative pressure; When the venous stent assembly is in the second state, the covered stent (11) and the limiting member (122) are both in a radially expanded state, the annular capsule body (121) is in a contracted state, and the inside of the annular capsule body (121) is under normal pressure; When the venous stent assembly is in the third state, the covered stent (11) is in a radially contracted state, the limiting member (122) is in a radially expanded state, the annular capsule body (121) is in an expanded state, and the inside of the annular capsule body (121) is under positive pressure, 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 covered stent (11); When the venous stent assembly is converted from the second state to the third state, the outer diameter of the limiting member (122) remains unchanged, and the covered stent (11) contracts along with the expansion of the annular capsule body (121).

2. The venous stent assembly of claim 1, wherein: The covered stent (11) comprises a self-expanding stent (111) and a covering film (112), the self-expanding stent (111) comprises a plurality of self-expanding stent units arranged in an axial direction and independently arranged, and the covering film (112) is fixedly connected with each self-expanding stent unit.

3. The venous stent assembly of claim 2, wherein: The proximal end of the self-expanding stent unit at the proximal end of the covered stent (11) is in a bare state without a covering film.

4. The venous stent assembly of claim 2, wherein: The covering film (112) comprises an inner covering film arranged on the inner surface of the self-expanding stent (111) and / or an outer covering film arranged on the outer surface of the self-expanding stent (111), and the inner covering film and the outer covering film are fixedly connected.

5. The venous stent assembly of claim 2, wherein: The self-expanding stent unit comprises a wave-shaped circular ring structure forming wave crests and wave troughs 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 covering film (112) is one or more of expanded polytetrafluoroethylene, polyethylene terephthalate, and thermoplastic polyurethane elastomer.

6. The venous stent assembly of claim 1, wherein: The proximal end of the covered stent (11) is in a bare state without a covering film and protruding from the proximal end of the annular capsule (12).

7. The venous stent assembly of claim 1, wherein: The medium is a gas and / or a liquid.

8. The venous stent assembly of claim 1, wherein: The annular capsule body (121) is compliant, and the protective film (123) is non-compliant or semi-compliant; and / or the material of the annular capsule body (121) is polyvinyl chloride, latex, or silicone, and the material of the protective film (123) is 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 material of the retention tube (124) is thermoplastic polyurethane elastomer or silicone rubber.

9. The venous stent assembly of claim 1, wherein: The material of the high-molecular coating is hydroxyacetic acid copolymer and / or poly-L-lactide.

10. An intravenous stent system, characterized by The venous stent system comprises the venous stent assembly according to any one of claims 1 to 9, a delivery catheter (13), and a recovery assembly.

11. The venous stent system of claim 10, wherein: The delivery catheter (13) is internally provided with a lumen extending from one end to the other end, the delivery catheter (13) is provided with a guide tip (131) at the distal end, the venous stent assembly is detachably sleeved at the distal end of the delivery catheter (13), and the guide tip (131) is in a bare state protruding from the distal end of the venous stent assembly.

12. The venous stent system of claim 10, wherein: The recovery assembly comprises 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 greater than the outer diameter of the covered stent (11) in a radially contracted state, the recovery hook is movably inserted into the recovery catheter (141), the recovery hook comprises a push-pull tube (1421) extending along the length direction of the recovery catheter (141), and a hook (1423) capable of hooking the proximal end of the covered stent (11) arranged at the distal end of the push-pull tube (1421), the push-pull tube (1421) is a hollow tubular structure with both ends open, and the inner diameter of the push-pull tube (1421) is greater than the outer diameter of the delivery catheter (13).

13. The venous stent system of claim 12, wherein: A plurality of extension rods (1422) are arranged along the circumferential direction of the distal end of the push-pull tube (1421), and the distal end of each extension rod (1422) is respectively provided with the hook (1423). When the plurality of extension rods (1422) extend out of the distal end portion of the recovery guide tube (141), the plurality of extension rods (1422) gradually extend away from the axis direction of the push-pull tube (1421) from the proximal end to the distal end.

14. The venous stent system of claim 10, wherein: The venous stent system further comprises an injection device and a suction device; and / or, the venous stent system further comprises a guide wire; and / or, the venous stent system further comprises a protection sheath (15), which is removably sleeved on the venous stent assembly.

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