Low-perfusion stent for chronic internal carotid artery occlusion

Abstract

The utility model provides a hypoperfusion stent for chronic internal carotid artery occlusion, and relates to the technical field of medical instruments, the hypoperfusion stent comprises a first stent and a flow limiting assembly which are mechanically connected, the flow limiting assembly is connected to the far end of the first stent, and the first stent is used for opening a vascular occlusion area; the first support and the flow limiting assembly have a pressing and holding state and an expansion state, and when the flow limiting assembly is in the expansion state, the flow of blood flowing to the far end of the flow limiting assembly can be limited. The flow limiting assembly is arranged at the far end of the first support playing a supporting role, when the first support opens a vascular occlusion position, the blood flow is controlled through the flow limiting assembly, the blood flow after recanalization can be gradually increased, the phenomenon of high perfusion caused by instantaneous increase of the blood flow is avoided, the surgical risk is reduced, and the surgical efficiency is improved. The flow limiting assembly is made of biodegradable materials and does not need to be taken out after operation, and the problem of high perfusion after recanalization of a blocked area can be solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical devices, and in particular relates to a low-perfusion stent for chronic occlusion of the internal carotid artery. Background Art

[0002] Internal carotid artery occlusion (ICAO) is a major factor contributing to ischemic stroke and can be categorized as acute or chronic, depending on the severity of onset. Occlusion lasting more than four weeks is generally classified as chronic, while occlusion lasting less than one week is classified as acute. Occlusion lasting one to four weeks is clinically rare and lacks a clear classification. The vast majority of patients are diagnosed with acute ICA occlusion after experiencing acute ischemic stroke, while most patients with chronic ICA occlusion do not experience obvious clinical symptoms in the early stages.

[0003] Treatments for chronic internal carotid artery occlusion include drug therapy, such as aspirin combined with clopidogrel antiplatelet aggregation therapy, as well as vascular reconstruction and revascularization.

[0004] Revascularization surgery for the treatment of chronic internal carotid artery occlusion offers advantages such as rapid results and excellent recanalization outcomes. However, balloon dilation of the previously occluded area can lead to a sudden increase in blood perfusion. Clinically, this can cause patients to become agitated and require sedatives, while severe cases can lead to intracranial aneurysms or cerebral hemorrhages, posing a risk to the patient's life and health.

[0005] To avoid hyperperfusion, localized balloon dilation of the occluded internal carotid artery is typically performed clinically. This involves initially dilating a portion of the occluded area, while a smaller balloon is used to expand the smaller blood flow channel in the remaining area. After the patient has adjusted for one to two months, a second surgery is performed to fully reopen the artery. This requires at least two surgeries, which are difficult and carry potential risks.

[0006] Therefore, it is necessary to provide an improved technical solution to the above-mentioned deficiencies in the prior art. Utility Model Content

[0007] The purpose of the present utility model is to provide a low-perfusion stent for chronic occlusion of the internal carotid artery, which can solve the problem of internal carotid artery occlusion while slowly increasing the blood flow after the blood vessel is recanalized, rather than increasing the blood flow instantaneously, thereby solving the problem of high perfusion after recanalization of the occluded area.

[0008] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0009] A low-perfusion stent for chronic occlusion of the internal carotid artery comprises a mechanically connected first stent and a flow-limiting assembly, wherein the flow-limiting assembly is connected to the distal end of the first stent, and the first stent is used to prop open the occluded area of the blood vessel. The first stent and the flow-limiting assembly have a gripping state and an expanded state. When the flow-limiting assembly is in the expanded state, it can limit the blood flow to the distal end of the flow-limiting assembly.

[0010] Preferably, the flow-limiting component is a filter or a dense mesh support, and the mesh size of the flow-limiting component gradually increases after contact with blood.

[0011] Preferably, the first bracket and the current limiting component are connected in a flexible manner.

[0012] Preferably, when the flow limiting component is in an expanded state, its outer diameter is smaller than the inner diameter of the blood vessel.

[0013] Preferably, the current limiting component is a dense mesh bracket, and the plurality of braided wires constituting the current limiting component are made of biodegradable material.

[0014] Preferably, the plurality of braided wires constituting the current limiting component are made of biodegradable magnesium alloy.

[0015] Preferably, all braided wires constituting the current limiting component are made of biodegradable materials.

[0016] Preferably, part of the braided wires of the current limiting component are made of biodegradable material, and the remaining braided wires are made of nickel-titanium alloy.

[0017] Preferably, part of the weft of the current limiting component is made of biodegradable material, and the remaining braided wires are made of nickel-titanium alloy.

[0018] Preferably, all wefts of the current limiting component are made of biodegradable material, and the remaining braided wires are made of nickel-titanium alloy.

[0019] Beneficial effects:

[0020] (1) The present invention provides a flow limiting component at the distal end of the first stent that plays a supporting role. When the first stent props up the occluded blood vessel, the flow limiting component controls the blood flow, thereby gradually increasing the blood flow after recanalization, avoiding the phenomenon of high perfusion caused by an instantaneous increase in blood flow, and reducing surgical risks.

[0021] (2) Part of the braided wire of the current limiting component can be degraded in the body, thereby gradually increasing the mesh diameter of the current limiting component and causing its current limiting ability to gradually decrease over time, thus eliminating the need to remove the current limiting component after surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting part of this application are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention.

[0023] Figure 1 This is a front view of a low-perfusion stent in an expanded state for chronic occlusion of the internal carotid artery provided by an embodiment of the present utility model.

[0024] Figure 2 This is a front view of the current limiting component in an embodiment of the present utility model.

[0025] Figure 3 for Figure 2 Schematic diagram of the current limiting component after degradation.

[0026] Figure 4 This is a front view of the current limiting component in an embodiment of the present utility model.

[0027] Figure 5 for Figure 2 Schematic diagram of the current limiting assembly after some of the weft lines have degraded.

[0028] Figure 6 for Figure 2 Schematic diagram of the current limiting assembly shown when all the wefts have degraded.

[0029] Figure 7 for Figure 2 Schematic diagram of the current limiting assembly after all the wefts have been degraded.

[0030] In the figure: 100, first bracket; 200, current limiting component; 201, warp; 202, weft. DETAILED DESCRIPTION

[0031] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0033] In the description of this utility model, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection or an indirect connection through an intermediate medium, and it can be internal connection between two elements, indirect connection, or an interactive relationship between two elements.

[0036] The present invention will be described in detail below with reference to the embodiments. It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0037] In response to the problem of high perfusion after current vascular recanalization surgery, the utility model provides a low perfusion stent for chronic internal carotid artery occlusion. The utility model can solve the problem of high perfusion after recanalization of the internal carotid artery while slowly increasing the blood flow after recanalization of the blood vessel, rather than increasing the blood flow instantly, thereby solving the problem of high perfusion after recanalization of the occluded area.

[0038] like Figure 1 As shown, the utility model provides a low perfusion stent for chronic occlusion of the internal carotid artery, including a mechanically connected first stent 100 and a flow limiting assembly 200, the flow limiting assembly 200 being connected to the distal end of the first stent 100, the first stent 100 being a memory alloy stent, the first stent 100 and the flow limiting assembly 200 having a clamped state and an expanded state, the first stent 100 being used to prop open the occluded area of the blood vessel when in the expanded state, and the flow limiting assembly 200 being able to limit the blood flow to the distal end of the flow limiting assembly 200 when in the expanded state.

[0039] Specifically, after the first stent 100 is released from the catheter, it self-expands due to the loss of the constraint of the catheter, so that the first stent 100 contacts the inner wall of the blood vessel at the occluded site, and the supporting force of the first stent 100 is used to expand the occluded site, expand the blood flow channel, and make the blood flow in the occluded site smoother; and after the flow limiting component 200 is released from the catheter, it expands at the distal end of the first stent 100 to block the blood flow, so that the blood flow to the distal end of the flow limiting component 200 is not too large, thereby avoiding a sudden increase in blood flow after the occluded site is reopened by the first stent 100, and preventing the occurrence of high perfusion problems.

[0040] The connection method between the first bracket 100 and the current limiting component 200 can be a flexible connection, for example, connecting the first bracket 100 and the current limiting component 200 through several metal or polymer wires; or the first bracket 100 and the current limiting component 200 can be connected by a ring buckle.

[0041] In the preferred embodiment of the present utility model, for example Figure 2 、 4 As shown, the current limiting component 200 is a filter or a dense mesh support, and the distal end of the current limiting component 200 can be provided with Figure 4 The opening shown can also be Figure 2 In the closed structure shown, the flow limiting component 200 can also be provided with openings at any other positions of its flow limiting part, and the size and number of the openings are not limited.

[0042] In a preferred embodiment of the present invention, the outer diameter of the first stent 100 is larger than the outer diameter of the flow limiting component 200. When the flow limiting component 200 is in an expanded state, its outer diameter is smaller than the inner diameter of the blood vessel, thereby preventing the blood flow from being excessively blocked by the flow limiting component 200 after recanalization.

[0043] In order to gradually increase the blood flow through the flow limiting component 200 after surgery, in the present invention, the mesh size of the flow limiting component 200 gradually increases after contact with blood. To achieve this effect, the several braided wires constituting the flow limiting component 200 are made of biodegradable material, so that these braided wires are gradually degraded after contact with blood, thereby increasing the pores of the flow limiting component 200 and reducing its flow limiting ability.

[0044] Specifically, the plurality of braided wires constituting the current limiting assembly 200 are made of biodegradable magnesium alloy, or other biodegradable materials suitable for medical use may be used instead.

[0045] Part or all of the braided wires constituting the flow limiting component 200 may be made of biodegradable materials. For example, in a preferred embodiment of the present invention, all of the braided wires constituting the flow limiting component 200 are made of biodegradable materials, so that the flow limiting component 200 is gradually degraded after the operation, and thus will not remain in the blood vessel, so that the distal end of the first stent 100 is completely unobstructed.

[0046] In a preferred embodiment of the present invention, part of the braided wires of the current limiting component 200 are made of biodegradable material, and the remaining braided wires are made of nickel-titanium alloy. More specifically, Figure 5 As shown, part of the wefts 202 of the current limiting component 200 is made of biodegradable material, and the remaining wefts 202 and warp 201 and other braided wires are made of nickel-titanium alloy, so that part of the mesh of the current limiting component 200 gradually increases after the operation, reducing its current limiting effect.

[0047] In the preferred embodiment of the present utility model, Figure 6 As shown, all the wefts 202 of the current limiting component 200 are made of biodegradable material, and the remaining braided wires are made of nickel-titanium alloy, so that all the wefts 202 of the current limiting component 200 gradually degrade after the operation, and only the warp 201 connecting the wefts 202 remains, as shown in FIG. Figure 7 As shown, there is no obvious obstruction to blood flow.

[0048] In summary:

[0049] This utility model incorporates a flow-limiting assembly at the distal end of the supporting first stent. When the first stent props up the occluded blood vessel, the flow-limiting assembly's blocking effect controls blood flow. This prevents a transient increase in blood flow after recanalization, resulting in hyperperfusion. This reduces the likelihood of post-operative sequelae such as cerebral hemorrhage and hyperemotional agitation. Furthermore, the flow-limiting assembly is made of a biodegradable material that gradually degrades post-operatively, thereby gradually reducing its obstruction to blood flow and allowing blood flow to slowly increase, eliminating the need for post-operative removal of the flow-limiting assembly.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A low perfusion stent for chronic occlusion of the internal carotid artery, characterized in that: It includes a mechanically connected first stent and a flow limiting component, wherein the flow limiting component is connected to the distal end of the first stent, the first stent is used to expand the occluded area of the blood vessel, the first stent and the flow limiting component have a gripping state and an expanded state, and when the flow limiting component is in the expanded state, it can limit the blood flow to the distal end of the flow limiting component.

2. A low perfusion stent for chronic occlusion of the internal carotid artery according to claim 1, characterized in that: The flow-limiting component is a filter or a dense mesh support. After the flow-limiting component comes into contact with blood, the mesh size of the filter gradually increases.

3. The low perfusion stent for chronic occlusion of the internal carotid artery according to claim 1, characterized in that: The first bracket and the current limiting component are connected in a flexible manner.

4. The low perfusion stent for chronic occlusion of the internal carotid artery according to claim 1, characterized in that: When the flow limiting component is in an expanded state, its outer diameter is smaller than the inner diameter of the blood vessel.

5. The low perfusion stent for chronic occlusion of the internal carotid artery according to claim 2, characterized in that: The current limiting component is a dense mesh bracket, and the plurality of braided wires constituting the current limiting component are made of biodegradable material.

6. The low perfusion stent for chronic occlusion of the internal carotid artery according to claim 5, characterized in that: The plurality of braided wires constituting the current limiting component are made of biodegradable magnesium alloy.

7. A low perfusion stent for chronic occlusion of the internal carotid artery according to claim 5 or 6, characterized in that: All braided wires constituting the current limiting component are made of biodegradable materials.

8. A low perfusion stent for chronic occlusion of the internal carotid artery according to claim 5 or 6, characterized in that: Part of the braided wires of the current limiting component are made of biodegradable material, and the remaining braided wires are made of nickel-titanium alloy.

9. The low perfusion stent for chronic occlusion of the internal carotid artery according to claim 8, characterized in that: Part of the weft wires of the current limiting component are made of biodegradable material, and the remaining braided wires are made of nickel-titanium alloy.

10. The low perfusion stent for chronic occlusion of the internal carotid artery according to claim 8, characterized in that: All the wefts of the current limiting component are made of biodegradable material, and the remaining braided wires are made of nickel-titanium alloy.

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