Covered stent and release device thereof

Abstract

The utility model provides a covered stent and a release device thereof, and relates to the technical field of medical instruments. The covered stent comprises metal stent rings and a covering film, the multiple metal stent rings are sequentially arranged at intervals and connected with the covering film, and under the auxiliary cooperation of the metal stent rings, the covering film can be kept shaped after being bent and deformed at the lesion position and is in a natural bent form, so that the covered stent is matched with the lesion position in shape, and the lesion position can be fixed. The covered stent has the bending deformation capacity and the capacity of keeping shaping after bending deformation at the same time, on this basis, the covered stent can be attached to the bent section of the aortic arch, the adherence between the stent and a blood vessel after implantation is effectively improved, the probability of occurrence of adverse events such as internal leakage is reduced, and the stent has the good application prospect. Particularly, the beak effect generated at the near end after the stent is released in interventional therapy can be solved, and the treatment effect on aortic aneurysm and aortic dissection is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of medical devices, in particular to a coated stent and a release device thereof. Background Art

[0002] In recent years, with the continuous development of endovascular interventional surgery, thoracic endovascular aortic repair (TEVAR) has been increasingly used in the clinical treatment of aortic aneurysm and aortic dissection due to its advantages such as safety, minimal invasiveness and rapid recovery.

[0003] Aortic aneurysm usually occurs in the part of the blood vessel where the wall strength or elasticity is insufficient, causing the wall to expand or stretch abnormally when blood passes through. It is more common in the abdominal aorta and thoracic aorta, while aortic dissection is more common in the thoracic aorta. The cause may be related to the patient's age, underlying medical history, genetic predisposition, etc.

[0004] If aortic aneurysm is not treated, the blood vessel wall may continue to expand and rupture, leading to death; if aortic dissection is not treated with intervention, the blood vessel endothelium may continue to tear, and the false blood lumen formed may block other branch blood vessels, causing ischemia and failure of organs in these areas, endangering the patient's life and health.

[0005] In order to inhibit the continuous tearing of arterial dissection and prevent aneurysm rupture, the current clinical treatment methods mostly use interventional surgery. Usually, a delivery system is used to place the covered stent at the location of the lesion through interventional methods to achieve the effect of closing the false lumen or aneurysm cavity. The covered stent can ensure that blood flows through the cavity formed by the covered stent. The covered stent can provide radial support force to ensure the fit between the blood vessel wall and the stent, and provide axial anti-displacement ability. The blood flowing through the blood vessel can be guided through the inner cavity surface of the covered stent to reduce the stress on the blood vessel wall at the location of the aneurysm sac, reduce the risk of blood vessel wall rupture at the aneurysm site, prevent blood from entering the arterial dissection, and guide blood to continuously pass through the lumen in the stent into blood vessels in other parts.

[0006] Another method of treating aneurysms and arterial dissections is surgery, which uses open surgery to resect the diseased area and implant artificial blood vessels to replace the diseased blood vessels. Blood flows through the lumen established by the artificial blood vessels, thereby achieving the therapeutic effect.

[0007] The applicant has found that there are at least the following technical problems in the prior art:

[0008] The interventional treatment of aneurysms and arterial dissections usually involves compressing the stent graft into the sheath, establishing a pathway in the surrounding arteries, delivering the stent graft to the lesion site, and then releasing the stent graft to achieve the treatment effect. Currently, the stent graft structures on the market are mostly straight-type designs. Due to the relatively complex structural morphology of the aorta, straight stents may generate a recoil force after release, and poor wall adhesion, which may cause the proximal end to be prone to "bird beak" phenomenon, leading to complications such as endoleak. In addition, stent release is mostly done by withdrawing the sheath, which may cause inaccurate positioning of the stent during the withdrawal process, poor morphology after release, and other problems. At the same time, due to the large diameter of the sheath, it is more invasive to the blood vessels.

[0009] Surgical procedures usually involve implanting artificial blood vessels at the site of the lesion. Although this treatment method can establish a good blood flow cavity and retain the biomechanical characteristics of the blood vessels to a certain extent, surgery causes large open wounds in the patient's body, and the prognosis recovery takes a long time, and the hospitalization time is long. It is not suitable for every patient, especially for patients with underlying medical history (such as hypertension, diabetes, heart disease, etc.). The operation has a high risk and may also cause a series of complications such as wound infection after the operation. Utility Model Content

[0010] The purpose of the utility model is to provide a stent graft and its release device to solve the technical problem that the stent graft structure in the prior art is mainly a straight design, and the straight stent may generate a straightening force after release, and the wall adhesion is poor, so that the proximal end is prone to "bird beak" phenomenon, which further causes complications such as internal leakage. The many technical effects that can be produced by the preferred technical solution among the many technical solutions provided by the utility model are described in detail below.

[0011] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0012] A coated stent comprises a metal stent ring and a coating, wherein a plurality of the metal stent rings are arranged in sequence and connected to the coating, and the coating can be bent and deformed at the lesion site to maintain a fixed shape so as to adapt to the shape of the lesion site.

[0013] Preferably, the metal stent ring is made of nickel-titanium alloy wire material.

[0014] Preferably, the wire diameter of the metal stent ring ranges from 0.3 mm to 0.6 mm.

[0015] Preferably, the coating forms a continuous horizontal segment, a curved segment and a vertical segment at the lesion location, and the bending radius of the center line of the curved segment ranges from 40 mm to 60 mm.

[0016] Preferably, the metal stent ring and the covering membrane are connected together by suturing or thermoforming.

[0017] A release device for a coated stent, comprising a constraint unit, a guide unit and the above-mentioned coated stent, wherein the constraint unit is detachably connected to the outside of the coated stent, the distal end of the constraint unit is connected to the connecting member of an external conveying device, the guide unit is detachably connected to the constraint unit, the proximal end of the guide unit is detachably connected to the coated stent, and the distal end of the guide unit is connected to the connecting member.

[0018] Preferably, the constraint unit includes a constraint membrane, a constraint membrane constraint rope and a constraint membrane traction rope, the constraint membrane is detachably connected to the guide unit, the constraint membrane pocket is arranged on the outside of the coated bracket and its two ends in the width direction are detachably connected through the constraint membrane constraint rope, the distal end of the constraint membrane constraint rope is connected to the connecting member, the proximal end of the constraint membrane traction rope is connected to the constraint membrane, and the distal end of the constraint membrane traction rope is connected to the connecting member.

[0019] Preferably, the guide unit comprises a constraining membrane guide rope, the constraining membrane guide rope is detachably connected to the constraining membrane, the proximal end of the constraining membrane guide rope is detachably connected to the coated stent, and the distal end of the constraining membrane guide rope is connected to the connecting member.

[0020] Preferably, the constraint unit includes a wrapping film and a wrapping film traction rope, the wrapping film is detachably connected to the guide unit, the wrapping film is wrapped around the outside of the coating bracket, the proximal end of the wrapping film traction rope is connected to the wrapping film, and the distal end of the wrapping film traction rope is connected to the connecting member.

[0021] Preferably, the guide unit includes a wrapping film guide rope, the main body of the wrapping film guide rope is wrapped around the outside of the film graft bracket and is detachably connected to the wrapping film, the proximal end of the wrapping film guide rope is detachably connected to the film graft bracket, and the distal end of the wrapping film guide rope is connected to the connecting member.

[0022] The beneficial effects of the utility model are as follows: with the assistance of the metal stent ring, the coating can maintain its shape after bending and deformation at the lesion site, presenting a natural curved shape, so that the coated stent and the shape of the lesion site are adapted to each other, and the coated stent has both the ability to bend and deform and the ability to maintain its shape after bending and deformation. On this basis, the coated stent can fit the curved section of the aortic arch, effectively improving the adhesion between the stent and the blood vessel after implantation, reducing the probability of adverse events such as endoleak, and especially solving the "bird's beak" effect produced at the proximal end after the stent is released during interventional treatment, thereby improving the treatment effect of aortic aneurysm and aortic dissection.

[0023] The covered stent has good bending flexibility and is used in conjunction with a release device. It is implanted into the lesion site of thoracic aortic aneurysm or thoracic aortic dissection through intracavitary intervention and a wire-pulling operation. It has a short postoperative recovery time, can reduce complications, and achieve lesion treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a structural diagram of the stent graft of the utility model;

[0026] Figure 2 This is a structural diagram of the second embodiment of the present utility model;

[0027] Figure 3 This is a structural diagram of the step S1 of the release method of the second embodiment of the present utility model;

[0028] Figure 4 This is a structural diagram of the step S2 of the release method of the second embodiment of the present utility model;

[0029] Figure 5 This is a structural diagram of the release method after step S3 of the second embodiment of the present utility model is completed;

[0030] Figure 6 This is a structural diagram of the step S1 of the release method of the third embodiment of the present utility model;

[0031] Figure 7 This is a structural diagram of the release method of Embodiment 3 of the present utility model after step S1 is completed;

[0032] Figure 8 This is a structural diagram of the step S2 of the release method of the third embodiment of the present utility model in progress;

[0033] Fig. 9 This is a structural diagram of the release method of the third embodiment of the present utility model after step S2 is completed;

[0034] In the figure, 11, metal stent ring; 12, coating;

[0035] 2. Constraint membrane;

[0036] 3. Constraint membrane and restraint rope;

[0037] 4. Restraint membrane traction rope;

[0038] 5. Constraint membrane guide rope;

[0039] 6. Stretch film;

[0040] 7. Wrap film traction rope;

[0041] 8. Wrap film guide rope. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the utility model.

[0043] In the description of the present invention, it should be understood that the terms "center", "lateral", "length", "width", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "side" and the like indicate positions or location relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing 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 operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0045] Embodiment 1

[0046] Reference Figure 1 The utility model provides a coated stent, including a metal stent ring 11 and a coating 12. The metal stent ring 11 is ring-shaped. Several metal stent rings 11 are arranged in sequence and are connected to the coating 12. The coating 12 connected to the metal stent ring 11 is similar to a cylinder, and the coated stent as a whole presents a thin film tubular component.

[0047] In this embodiment, the metal stent ring 11 is preferably made of an elastic material with shape memory, and is further preferably made of a nickel-titanium alloy wire material, and the wire diameter of the metal stent ring 11 is preferably in the range of 0.3 mm to 0.6 mm. In this way, the metal stent ring 11 can have superelasticity and shape memory, so that during the use of the stent graft, the metal stent ring 11 can be compressed in the radial direction and can be restored to its original state;

[0048] During production, the main body of the metal support ring 11 can be formed by heat treatment in conjunction with tooling, and then connected to the coating 12 .

[0049] With the assistance of several metal stent rings 11, the coating 12 can maintain its shape after bending and deformation at the lesion site, presenting a natural curved shape, so that the coated stent and the shape of the lesion site are adapted to each other. The metal stent ring 11 made of superelastic metal material also enables the coated stent to have the ability to bend and deform and the ability to maintain its shape after bending and deformation. On this basis, the coated stent can fit the curved section of the aortic arch, effectively improving the adhesion between the stent and the blood vessel after implantation, reducing the probability of adverse events such as internal leakage, and especially solving the "bird's beak" effect produced at the proximal end after the stent is released during interventional treatment.

[0050] According to actual use needs, the coating 12 can form a continuous three-segment design at the lesion location, namely, a horizontal segment, a curved segment, and a vertical segment. The bending radius of the center line of the curved segment ranges from 40 mm to 60 mm. Such a setting within this data range can better fit the anatomical features of the thoracic aorta, thereby increasing the wall adhesion of the coating 12.

[0051] In this embodiment, the coating 12 may be made of fluorine-containing polymers including but not limited to expanded polytetrafluoroethylene (e-PTFE), polyester, polyurethane, perfluoroelastomer, polytetrafluoroethylene, silicone, urethane, ultra-high molecular weight polyethylene, aramid fiber and combinations thereof;

[0052] When the coating 12 is made of a thin film material formed of polyester or polyurethane, the metal stent ring 11 and the coating 12 can be sutured together to form a whole by surgical thread (such as nylon thread);

[0053] When the coating 12 is made of a thin film material formed by e-PTFE, PTFE, etc., the metal stent ring 11 and the coating 12 can be connected together to form a whole by hot pressing;

[0054] In addition to the above connection forms, other connection forms may be used between the metal stent ring 11 and the coating 12 .

[0055] Embodiment 2

[0056] Reference Figure 2 to Figure 3 The utility model also provides a release device for a coated stent, including a constraint unit, a guide unit and the above-mentioned coated stent, the constraint unit is detachably connected to the outside of the coated stent, the distal end of the constraint unit is connected to the connecting member of the external conveying device, the guide unit is detachably connected to the constraint unit, the proximal end of the guide unit is detachably connected to the coated stent, and the distal end of the guide unit is connected to the connecting member.

[0057] In this patent, the term "proximal" refers to the side of the device closer to the heart, and "distal" refers to the side farther from the heart.

[0058] As an optional embodiment, the constraint unit includes a constraint membrane 2, a constraint membrane constraint rope 3 and a constraint membrane traction rope 4, and the guide unit includes a constraint membrane guide rope 5;

[0059] The constraint membrane guide rope 5 is detachably connected to the constraint membrane 2, the proximal end of the constraint membrane guide rope 5 is detachably connected to the coated stent, and the distal end of the constraint membrane guide rope 5 is connected to the connecting member. When the constraint membrane 2 is retracted under the traction of the constraint membrane traction rope 4, the constraint membrane 2 can be retracted along the constraint membrane guide rope 5, thereby effectively preventing the constraint membrane 2 from flanging and falling off due to excessive blood flow impact;

[0060] The constraint membrane 2 is arranged outside the stent graft and its two ends in the width direction are detachably connected by the constraint membrane constraint rope 3. The distal end of the constraint membrane constraint rope 3 is connected to the connecting member. The constraint membrane 2 can constrain the stent graft in a radially compressed state and deliver it to the lesion site through an external delivery device. The material of the constraint membrane 2 can preferably include fluorine-containing polymers such as expanded polytetrafluoroethylene (ePTFE), polyester, polyurethane, and perfluoroelastomer.

[0061] In this embodiment, it is preferred that a plurality of through holes are opened on the constraint membrane 2, and the constraint membrane constraint rope 3 passes through the through holes in sequence from the proximal end to the distal end, so that the constraint membrane constraint rope 3 is fixed to the constraint membrane 2 in a manner similar to chain suture;

[0062] The proximal end of the constraint membrane traction rope 4 is connected to the constraint membrane 2, and the distal end of the constraint membrane traction rope 4 is connected to the connecting member. The constraint membrane traction rope 4 can withdraw the constraint membrane 2 from the blood vessel into the sheath after the constraint membrane 2 is released.

[0063] The method of using the release device mentioned in this embodiment is:

[0064] S1. First, operate the connecting member on the external delivery device at the distal end, and the connecting member provides a sufficiently large pulling force to withdraw the constraint membrane constraint rope 3. After the constraint membrane constraint rope 3 is completely withdrawn into the sheath, the constraint membrane 2 is released, and the stent graft can also be restored from the collapsed structure state to the expanded state;

[0065] S2. After the restraint membrane restraint rope 3 is withdrawn, the restraint membrane 2 is retracted by pulling the restraint membrane traction rope 4. During the retraction process, the withdrawal path of the restraint membrane 2 can be recovered into the sheath along the restraint membrane guide rope 5 until it is completely recovered. The restraint membrane guide rope 5 can prevent the restraint membrane 2 from flanging or recovery failure due to excessive blood flow impact when it is withdrawn into the sheath.

[0066] S3. Manipulate the connecting member to recover the restraining membrane guide rope 5.

[0067] After the release, the covered stent is in a curved state. Because the central curvature of its curved segment is close to the bending radius of the aortic arch, it has better wall adhesion after release and can effectively reduce the probability of adverse events such as bird beak and internal leakage.

[0068] The covered stent has good bending flexibility. Combined with the above-mentioned release device and release method, it is implanted into the lesion site of thoracic aortic aneurysm or thoracic aortic dissection through intracavitary intervention and wire pulling operation. The postoperative recovery time is short, complications can be reduced, and lesion treatment can be achieved.

[0069] The restraint membrane restraint rope 3, restraint membrane traction rope 4 and restraint membrane guide rope 5 mentioned in this embodiment can be selected from metals, polymers or natural materials and can include traditional medical grade materials such as nylon, polyacrylamide, polycarbonate, polyethylene, polyformaldehyde, polymethyl methacrylate, elastomeric silicone polymers, and metals such as stainless steel, cobalt-chromium alloy and nitinol can also be selected.

[0070] The end of the rope body mentioned in this embodiment and its connecting structure are preferably connected by locking or knotting.

[0071] Embodiment 3

[0072] Reference Figure 2 to Figure 3 The utility model also provides a release device for a coated stent, including a constraint unit, a guide unit and the above-mentioned coated stent, the constraint unit is detachably connected to the outside of the coated stent, the distal end of the constraint unit is connected to the connecting member of the external conveying device, the guide unit is detachably connected to the constraint unit, the proximal end of the guide unit is detachably connected to the coated stent, and the distal end of the guide unit is connected to the connecting member.

[0073] In this patent, the term "proximal" refers to the side of the device closer to the heart, and "distal" refers to the side farther from the heart.

[0074] As an optional embodiment, the restraining unit includes a wrapping film 6 and a wrapping film traction rope 7, and the guiding unit includes a wrapping film guide rope 8;

[0075] The main body of the wrap film guide rope 8 is wrapped around the outside of the stent graft and is detachably connected to the wrap film 6. The proximal end of the wrap film guide rope 8 is detachably connected to the stent graft, and the distal end of the wrap film guide rope 8 is connected to the connecting member. The wrap film 6 and the wrap film guide rope 8 can jointly constrain the stent graft in a radially compressed state.

[0076] The wrapping film 6 is wrapped around the outer side of the stent graft;

[0077] The proximal end of the wrapping film traction rope 7 is connected to the wrapping film 6 , and the distal end of the wrapping film traction rope 7 is connected to the connecting member.

[0078] The method of using the release device mentioned in this embodiment is:

[0079] S1. When the coated stent reaches the lesion location, first operate the connecting component on the external delivery device at the distal end. The connecting component provides a large enough pulling force to pull the wrapping film traction rope 7. The wrapping film 6 is retracted through the wrapping film traction rope 7. The retraction path of the wrapping film 6 can be carried out along the trajectory of the wrapping film guide rope 8 and gradually recovered into the sheath. In this way, it can ensure that while the coated stent is restrained, the wrapping film 6 can be prevented from being impacted by blood flow during the retraction process and causing recovery failure.

[0080] S2. After the wrapping film 6 is recovered, the wrapping film guide rope 8 is recovered, and the wrapping film guide rope 8 is pulled by the connecting member on the external conveying device at the far end to recover the wrapping film guide rope 8. During the recovery process, the stent graft will gradually recover from the collapsed structure state to the expanded state. When the wrapping film guide rope 8 is recovered, the stent graft is released as a whole, forming Fig. 9 effect.

[0081] After the release, the covered stent is in a curved state. Because the central curvature of its curved segment is close to the bending radius of the aortic arch, it has better wall adhesion after release and can effectively reduce the probability of adverse events such as bird beak and internal leakage.

[0082] The covered stent has good bending flexibility. Combined with the above-mentioned release device and release method, it is implanted into the lesion site of thoracic aortic aneurysm or thoracic aortic dissection through intracavitary intervention and wire pulling operation. The postoperative recovery time is short, complications can be reduced, and lesion treatment can be achieved.

[0083] The wrap film traction rope 7 and wrap film guide rope 8 mentioned in this embodiment can be selected to include metal, polymer or natural materials and can include traditional medical grade materials such as nylon, polyacrylamide, polycarbonate, polyethylene, polyoxymethylene, polymethyl methacrylate, elastomeric silicone polymers, and metals such as stainless steel, cobalt-chromium alloy and nitinol can also be selected.

[0084] The above are only specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A stent graft, characterized in that: It comprises a metal stent ring (11) and a coating (12), wherein a plurality of the metal stent rings (11) are arranged in sequence at intervals and are all connected to the coating (12), and the coating (12) can be bent and deformed at the lesion location and then remain in a fixed shape so as to be compatible with the shape of the lesion location.

2. The stent graft according to claim 1, characterized in that: The metal support ring (11) is made of nickel-titanium alloy wire material.

3. The stent graft according to claim 2, characterized in that: The wire diameter of the metal support ring (11) ranges from 0.3 mm to 0.6 mm.

4. The stent graft according to claim 1, characterized in that: The coating (12) forms a continuous horizontal section, a curved section and a vertical section at the lesion position, and the bending radius of the center line of the curved section ranges from 40 mm to 60 mm.

5. The stent graft according to claim 1, characterized in that: The metal stent ring (11) and the covering membrane (12) are connected together by suturing or by thermoforming.

6. A release device for a stent graft, characterized in that: It comprises a constraint unit, a guide unit and the coated stent according to any one of claims 1 to 5, wherein the constraint unit is detachably connected to the outside of the coated stent, the distal end of the constraint unit is connected to the connecting member of an external transport device, the guide unit is detachably connected to the constraint unit, the proximal end of the guide unit is detachably connected to the coated stent, and the distal end of the guide unit is connected to the connecting member.

7. The release device of the stent graft according to claim 6, characterized in that: The constraint unit comprises a constraint membrane (2), a constraint membrane constraint rope (3) and a constraint membrane traction rope (4); the constraint membrane (2) is detachably connected to the guide unit; the constraint membrane (2) is arranged on the outside of the coated bracket and its two ends in the width direction are detachably connected through the constraint membrane constraint rope (3); the distal end of the constraint membrane constraint rope (3) is connected to the connecting member, the proximal end of the constraint membrane traction rope (4) is connected to the constraint membrane (2), and the distal end of the constraint membrane traction rope (4) is connected to the connecting member.

8. The release device of the stent graft according to claim 7, characterized in that: The guide unit comprises a constraining membrane guide rope (5), the constraining membrane guide rope (5) is detachably connected to the constraining membrane (2), the proximal end of the constraining membrane guide rope (5) is detachably connected to the coated stent, and the distal end of the constraining membrane guide rope (5) is connected to the connecting member.

9. The release device of the stent graft according to claim 6, characterized in that: The restraining unit includes a wrapping film (6) and a wrapping film traction rope (7); the wrapping film (6) is detachably connected to the guiding unit; the wrapping film (6) is wrapped around the outer side of the coated bracket; the proximal end of the wrapping film traction rope (7) is connected to the wrapping film (6); and the distal end of the wrapping film traction rope (7) is connected to the connecting member.

10. The release device of the stent graft according to claim 9, characterized in that: The guide unit comprises a wrapping film guide rope (8), the main body of which is wrapped around the outside of the graft bracket and is detachably connected to the wrapping film (6), the proximal end of the wrapping film guide rope (8) is detachably connected to the graft bracket, and the distal end of the wrapping film guide rope (8) is connected to the connecting member.

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