Covered stent and stent system
By adding a detachable protective sleeve to the free end of the anchor, the problem of the anchor puncturing the membrane during the sheathing process of the covered stent was solved, thus achieving safe and reliable implantation of the covered stent and reducing perioperative risks.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LIFETECH SCI (SHENZHEN) CO LTD
- Filing Date
- 2021-12-31
- Publication Date
- 2026-05-12
AI Technical Summary
During the sheathing process of existing covered stents, the tips of the anchors can easily come into contact with and puncture the stacked and mutually compressed covered stents, causing damage to the covered stents and affecting the overall effect of the implant.
A detachable protective sleeve is added to the free end of the anchor. Through the combination of the sheath design and the protective sleeve, damage to the film is avoided by the anchor during sheathing. The protective sleeve automatically detaches from the sheath during release, ensuring the integrity of the film support.
This effectively avoids damage to the covering membrane caused by anchors during the sheathing process of the covered stent, ensuring the integrity and safety of the implant and reducing perioperative mortality.
Smart Images
Figure CN116407367B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of interventional medical device technology, and in particular to a covered stent and stent system. Background Technology
[0002] With the rapid increase in the incidence of hypertension, the incidence of arterial-related diseases is also rising significantly, and is projected to increase by more than 40% in the next 5 to 7 years. Acute Stanford aortic dissection type A (AADA) is the most common and dangerous aortic emergency in cardiovascular surgery. Without treatment, the mortality rate of AADA within one week is as high as 50-91%. With only conservative medical treatment, the 24-hour mortality rate reaches 20%, and the 48-hour mortality rate can reach 30%. Therefore, AADA, once diagnosed, requires emergency surgical intervention if there are no contraindications. However, even under modern medical conditions, the perioperative mortality rate is as high as 15-35%.
[0003] Currently, minimally invasive endovascular interventional surgery can be used to treat the above-mentioned diseases. Specifically, a covered stent is implanted into the blood vessel to isolate the blood flow from the aortic dissection. During use, the stent is typically first compressed and loaded into a sheath in its unstressed, naturally positioned state, facilitating subsequent transport and release to the designated site. During stent loading, the stent transitions from a naturally positioned state to a compressed state. After transporting the stent to the designated location, it is released from the sheath, returning to its naturally positioned state.
[0004] Because existing covered stents typically enhance their anchoring ability in blood vessels by incorporating anchors, the manufacturing process generally involves first covering the inner and outer surfaces of the bare stent with a membrane, then using specialized tools to insert the anchors through the outer surface of the membrane, and finally performing heat treatment to bond the membrane to the bare stent. However, in existing technologies, because the anchors have sharp points, during the sheathing of the covered stent, the pressure from the sheath causes the anchor tips to converge towards the axis, easily contacting and piercing the stacked and mutually compressed membranes. Summary of the Invention
[0005] Based on this, the present invention provides a covered stent and stent system to solve the problem that the anchor of the covered stent is prone to detach from the covering at the root of the anchor during the release process.
[0006] The present invention provides a film-coated support, comprising a support body, a film, and anchors disposed on the support body. The support body includes a natural state without being subjected to other external forces and a compressed state after loading. The film covers the support body, and the free end of the anchor passes through the film and is covered with a removable protective sleeve.
[0007] In one embodiment, the protective sleeve is fitted over the surface of the coating, and the protective sleeve isolates the free end of the anchor barb from the coating.
[0008] In one embodiment, the protective sleeve includes a plurality of protective units, and the anchor spikes are a plurality of units, wherein the protective units are respectively fitted onto and cover the free ends of the anchor spikes.
[0009] A stent system includes the aforementioned covered stent and a sheath, the inner diameter of which is larger than the outer diameter of the stent body in its natural state.
[0010] In one embodiment, the outlet of the sheath is provided with a constricted section, the minimum diameter of which is smaller than the outer diameter of the protective sleeve.
[0011] In one embodiment, the inner wall of the sheath is provided with an adhesive portion that restricts the movement of the protective sleeve toward the outlet of the sheath.
[0012] In one embodiment, the inner wall of the sheath is provided with a groove corresponding to the protective sleeve, and the groove restricts the movement of the protective sleeve toward the outlet of the sheath.
[0013] In one embodiment, the protective sleeve includes a retainer extending toward the proximal end of the overcoated support.
[0014] In one embodiment, the angle between the card plate and the axis is 30-60°.
[0015] In one embodiment, the groove extends toward the outlet direction of the sheath.
[0016] In one embodiment, the protective sleeve has a pull cord attached to its end.
[0017] The covered stent and stent system provided by the present invention avoids the risk of the free end of the anchor needle contacting and piercing the stacked and mutually squeezed covered stent during the sheathing process by adding a detachable protective sleeve to the free end of the anchor needle, thereby avoiding the problem of overall implant failure due to damage to the covered stent. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of a film-coated scaffold in the prior art;
[0019] Figure 2 This is a schematic diagram of the structure of an anchor spike in the existing technology;
[0020] Figure 3 This is a schematic diagram of the sheathing process of a film-coated stent in the prior art;
[0021] Figure 4 This is a schematic diagram of the natural state of anchor spikes in existing technology;
[0022] Figure 5 This is a schematic diagram of the compression state of anchor spikes in existing technology;
[0023] Figure 6 This is a schematic cross-sectional view of the anchor spikes of the film-coated support in Embodiment 1 of the present invention;
[0024] Figure 7 This is a schematic diagram of the anchor spikes of the film-coated support in Embodiment 1 of the present invention;
[0025] Figure 8 This is a schematic diagram of the release state of the covered stent in Embodiment 1 of the present invention;
[0026] Figure 9 This is a schematic diagram of the first state of the release phase of the stent system in Embodiment 2 of the present invention;
[0027] Figure 10 This is a schematic diagram of the second state of the release phase of the stent system in Embodiment 2 of the present invention;
[0028] Figure 11 This is a schematic cross-sectional view of the anchor bolt position structure of the support system in Embodiment 3 of the present invention;
[0029] Figure 12 This is a schematic diagram of the second state of the release phase of the stent system in Embodiment 3 of the present invention;
[0030] Figure 13 This is a schematic cross-sectional view of the anchor spikes in the support system of Embodiment 4 of the present invention;
[0031] Figure 14 This is a schematic diagram of the anchor spike structure of the support system in Embodiment 4 of the present invention. Detailed Implementation
[0032] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.
[0033] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0035] In the field of interventional medical devices, the proximal end of an implant (such as a stent) after deployment is typically defined as the end closer to the heart and the distal end as the end farther from the heart. "Axial" generally refers to the length direction of the implant during delivery, while "radial" generally refers to the direction perpendicular to the implant's "axial" direction. Based on this principle, the "axial" and "radial" of any component of the implant are defined.
[0036] To better illustrate the innovative aspects of this invention, we will first introduce the existing technology.
[0037] Existing technology:
[0038] like Figure 1-5 As shown, Figure 1 This is a schematic diagram of the structure of the covered scaffold 100 in the prior art. Figure 2 This is a schematic diagram of the structure of the anchor 11 in the prior art. Figure 3 This is a schematic diagram of the sheathing process of the covered stent 100 in the prior art. Figure 4 This is a schematic diagram of the natural state of the anchor barb 11 in the prior art. Figure 5 This is a schematic diagram of the sheathed state of the anchor spike 11 in the prior art.
[0039] The covered stent 100 includes a bare stent 10 and a covering 20. The bare stent 10 is made of a biocompatible material, such as nickel-titanium or stainless steel. Generally, the bare stent 10 includes multiple spaced metal coils. The covering 20 is made of a biocompatible polymer material, such as PTFE, FEP, or PET. To increase the anchoring ability of the covered stent 100 after implantation, an anchor 11 is typically placed on a metal coil near the proximal end of the bare stent 10 to enhance its anchoring ability. The anchor 11 has a pointed tip, which facilitates its anchoring in the blood vessel. The extension direction of the anchor 11 is inclined relative to the axis of the bare stent 10 (i.e., the axis of the covered stent 100), and the angle between the anchor 11 and the bare stent 10 is α.
[0040] like Figure 3 As shown, when the covered support 100 is inserted into the sheath 200, the covered support 100 will gradually compress into the interior of the sheath 20. Since the distance from the free end of the anchor 11 to the longitudinal central axis of the bare support 10 is slightly greater than the distance from the covered support 200 to the longitudinal central axis of the bare support 10, the free end of the anchor 11 is located outside the covered support 20.
[0041] like Figure 4 As shown, the coating 20 covers the surface of the bare support 10, the root of the anchor 11 is connected to the bare support 10, and the free end of the anchor 11 passes through the coating 20. This is because the existing production process first covers the bare support 10 with the coating 20, then uses a special tool to push the anchor 11 out from the outer surface of the coating 20, and finally heat-treats the coating 20 to bond the coating 20 to the bare support 10 and the root of the anchor 11. In other words, the coating 20 partially covers the root of the anchor 11.
[0042] Combined with appendix Figure 5 To provide further explanation, such as Figure 5 As shown, the anchor 11 is in a compressed state in the sheath. It should be noted that the anchor 11 and the bare support 10 are made of the same material, which is a metal material with memory function. The membrane 20 covers the bare support 10 and moves with the movement of the bare support 10. Therefore, during the release of the membrane support 100, the movement of the bare support 10 and the anchor 11 drives the movement of the membrane 20.
[0043] However, during the transport process, the membranes 20 stack and squeeze each other. Due to the compression of the sheath tube 200, the tip (i.e., the free end) of the anchor 11 may come into contact with and pierce the stacked and squeezed membranes 20. It is worth noting that the anchor 11 is most likely to pierce the membranes 20 during the sheathing process of the membrane support 100. This is because both the anchor 11 and the membranes 20 are compressed from their natural state along the inner wall of the sheath tube 200 to a compressed state. During this process, the membranes 20 are squeezed and stacked, while the tip of the anchor 11 is constantly moving towards the axis.
[0044] Therefore, in order to solve the problems existing in the prior art, the present invention adopts a variety of implementation methods.
[0045] Example 1
[0046] Reference Figure 6-8 As shown, Figure 6 This is a schematic cross-sectional view of the anchor 21 position of the film-coated support 100 in Embodiment 1 of the present invention. Figure 7 This is a schematic diagram of the anchor 21 of the film-coated support 100 in Embodiment 1 of the present invention. Figure 8 This is a schematic diagram of the released state of the covered stent 100 in Embodiment 1 of the present invention. In Embodiment 1, the bare stent 10 includes multiple spaced metal coils made of biocompatible materials such as nickel-titanium or stainless steel. The covering 20 covers the surface of the bare stent 10 and is made of a biocompatible polymer material such as PTFE, FEP, or PET. The root of the anchor 21 is connected to the bare stent 10, and the free end of the anchor 21 passes through the covering 20 and is exposed. The tail end of the anchor 21 is pointed, which facilitates the anchoring of the anchor 21 in the blood vessel. The extension direction of the anchor 21 is inclined relative to the axis of the bare support 10 (i.e. the axis of the covered support 100). The angle between the anchor 21 and the bare support 10 is β, which satisfies 20° < β < 50°. When the angle β is too small, the anchoring force of the anchor 21 is small, and the covered support is prone to displacement. When the angle β is too large, the anchor 21 will generate a large stress at the root of the anchor during the compression process of the sheath, which will affect the quality of use of the covered support.
[0047] A protective sleeve 12 is fitted on the free end of the anchor 21. The protective sleeve 12 is made of elastic materials such as silicone and rubber. In the compressed state, the protective sleeve 12 is wrapped in a ring on the surface of the coating 20. The protective sleeve 12 isolates the tip of the anchor 21 from the coating 20, so that the anchor 21 will not damage the coating 20 or the sheath.
[0048] In another embodiment, the protective sleeve 12 includes a plurality of protective units, which are respectively fitted and covered on the free end of the anchor spike. The protective units can be connected to each other or can be independent of each other.
[0049] It should be noted that the protective sleeve 12 detaches from the main body of the covered support after the support is released, thus ensuring that the protective sleeve 12 does not affect the normal operation of the covered support. Therefore, in combination with Figure 9 , Figure 9 This is a schematic diagram of a stent system according to an embodiment. The outlet of the sheath 200 includes a constricted section 201. In the compressed state, the inner wall of the sheath 200 abuts against the protective sleeve 12. Since the sheath 200 compresses the entire covered stent 100, and the free end of the anchor 21 is located at the outermost edge of the covered stent 100 in its natural state, the point where the covered stent 100 experiences the greatest stress from the pressure of the sheath is the free end of the anchor 21, which is the position of the protective sleeve 12. When the covered stent 100 leaves the opening of the sheath 200, it passes through the constriction section 201. Due to the reduced diameter of the constriction section 201, the stress on the protective sleeve 12 by the sheath 200 further increases. The protective sleeve 12 is an elastic element. In this embodiment, the outer diameter D of the protective sleeve 12 increases and decreases with deformation, but always satisfies that D is less than the minimum diameter d of the constriction section 201. Therefore, the protective sleeve 12 can no longer advance before reaching the exit of the constriction section 201. However, the covered stent 100 continues to be delivered forward, so the protective sleeve 12 detaches from the covered stent 100. In the end, only the stent body of the covered stent 100 is released and implanted into the human body. At the same time, since the outer diameter D of the protective sleeve 12 is less than the minimum diameter d of the constriction section 201, the protective sleeve 12 always stays inside the sheath 200 and will not enter the human body to cause harm.
[0050] In another embodiment, an adhesive portion can be added to the inner wall of the constricted section 201 or the inner wall of the sheath 200. During the release of the covered support, when the anchor 21 reaches the adhesive portion, the free end of the anchor 21 continues to move towards the outlet with the protective sleeve 12. After the adhesive portion adheres to the protective sleeve 12, it prevents the protective sleeve 12 from detaching from the sheath 200 along with the covered support, thereby achieving automatic detachment of the protective sleeve 12. At the same time, since the protective sleeve 12 is adhered to the adhesive portion when it moves in the release direction, the protective sleeve 12 always remains inside the sheath 200 and will not enter the human body to cause harm.
[0051] Example 2
[0052] Reference Figure 9-10 , Figure 9 This is a schematic diagram of the first state of the release phase of the stent system in Embodiment 2 of the present invention. Figure 10This is a schematic diagram of the second state of the release phase of the stent system in Embodiment 2 of the present invention. Embodiment 2 uses the same covered stent 100 as Embodiment 1. The difference between this embodiment and Embodiment 1 is that this embodiment uses a new sheath 300. The outlet position of the sheath 300 is provided with a groove 301, which corresponds to the protective sleeve 12 and is used to accommodate the protective sleeve 12. Specifically, when the covered stent 100 is ready to be released, that is, when it moves from the first state to the second state, the protective sleeve 12 reaches the groove 301. Due to the restoring force of the anchor 21, the anchor 21 drives the protective sleeve 12 to engage in the groove. The groove 301 limits the protective sleeve 12. When the coating bracket 100 continues to move forward (i.e., on the left side of the figure), the protective sleeve 12 is restricted and stays in the groove 301 position. As the coating bracket 100 continues to deliver forward, since the coating bracket 100 as a whole has a tendency to return to its natural state, even if it leaves the anchor 21, the protective sleeve 12 is still held and restricted inside the groove 301 by the bracket body, so that the protective sleeve 12 will not be released with the coating bracket 100.
[0053] Example 3
[0054] Reference Figure 11-12 , Figure 11 This is a schematic cross-sectional view of the anchor bolt position structure of the support system in Embodiment 3 of the present invention. Figure 12 This is a schematic diagram of the second state of the release phase of the support system in Embodiment 3 of the present invention. This embodiment is an improvement based on Embodiment 2. The difference is that the free end of the anchor 31 is provided with a protective sleeve 13. The protective sleeve 13 includes a clamping plate 131 that extends inclined toward the proximal end of the covered support. The angle between the clamping plate 131 and the axis is preferably 30-60°. For the sheath 40, the groove 401 follows the extension direction of the clamping plate 13 (i.e., extends toward the outlet direction of the sheath 40). When the clamping plate 13 enters the groove 401, the clamping plate and the protective sleeve 13 are restricted and stay in the groove 401 position. The covered support 100 continues to be delivered forward. Since the covered support 100 as a whole has a tendency to rebound to its natural state, even if it leaves the anchor 31, the protective sleeve 12 is still held and restricted inside the groove 401 by the support body, so that the protective sleeve 12 will not be released with the covered support 100.
[0055] It should be noted that if the groove 401 is not extended but is arranged radially, the card plate 13 can still achieve the same effect when it enters the groove 401, that is, it always abuts against a certain side of the groove 401 during the release of the bracket.
[0056] Example 4
[0057] Reference Figure 13-14 , Figure 13 This is a schematic cross-sectional view of the anchor bolt position structure of the support system in Embodiment 4 of the present invention. Figure 14This is a schematic diagram of the anchor position structure of the support system in Embodiment 4 of the present invention. In this embodiment, the free end of the anchor 41 is provided with a protective sleeve 14, and the tail of the protective sleeve 14 is connected with an auxiliary line 141. The auxiliary line 141 extends along the sheath to the handle position. When the operator pulls the auxiliary line 141 at the handle position, the maximum displacement of the protective sleeve 14 can be limited, so that the protective sleeve 14 automatically disengages from the anchor 41 when the covered support is released. At the same time, since the auxiliary line 141 always limits the protective sleeve 14, the protective sleeve 14 always stays inside the sheath and will not enter the human body to cause harm.
[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0059] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A covered stent, comprising a stent body, a covering, and anchors disposed on the stent body, wherein the stent body includes a natural state free from other external forces and a compressed state after loading, characterized in that, The membrane covers the support body, the free end of the anchor passes through the membrane and is covered by a removable protective sleeve; in the compressed state, the protective sleeve is fitted over the surface of the membrane, and the protective sleeve isolates the free end of the anchor from the membrane.
2. The covered stent according to claim 1, characterized in that, The protective cover is made of silicone or rubber.
3. The covered stent according to claim 1, characterized in that, The protective sleeve includes several protective units, and there are several anchors. The protective units are respectively fitted onto and cover the free ends of the anchors.
4. A support system, characterized in that, The covered stent according to any one of claims 1-3 further includes a sheath, the inner diameter of which is smaller than the outer diameter of the stent body in its natural state.
5. The support system according to claim 4, characterized in that, The sheath has a constricted section at its outlet, and the minimum diameter of the constricted section is smaller than the outer diameter of the protective sleeve.
6. The support system according to claim 4, characterized in that, The inner wall of the sheath is provided with an adhesive portion, which restricts the movement of the protective sleeve toward the outlet of the sheath.
7. The support system according to claim 4, characterized in that, The inner wall of the sheath is provided with a groove corresponding to the protective sleeve, and the groove restricts the movement of the protective sleeve toward the outlet of the sheath.
8. The support system according to claim 4, characterized in that, The protective sleeve includes a retainer extending toward the proximal end of the covered support.
9. The support system according to claim 8, characterized in that, The angle between the card plate and the axis is 30-60°.
10. The support system according to claim 7, characterized in that, The groove extends toward the outlet of the sheath.
11. The support system according to claim 4, characterized in that, The protective sleeve has a pull cord attached to its end.