CN110916860A - A stent device for sealing bifurcated aneurysms - Google Patents

Abstract

The present invention provides a stent device for sealing a bifurcation aneurysm, the stent device at least comprising a support section for being arranged on the inner wall of a blood vessel to play a supporting role, and for being arranged in a bifurcation area of a blood vessel to allow blood to flow in the blood vessel. The blood penetrating segment for the flow of the blood vessel bifurcation region, and the sealing segment for placement at the neck of the bifurcated aneurysm to seal the aneurysm, the support segment, the blood penetrating segment, and the sealing segment along the stent device The axial direction extends from the proximal end to the distal end, and the radial dimension of the sealing segment is set to expand relative to the blood penetrating segment so that the sealing segment fits snugly with the neck of the bifurcated aneurysm .

Description

A support device for sealing branching aneurysm

Technical Field

The present invention relates to medical devices, and more particularly to a stent device for occluding bifurcated aneurysms.

Background

Aneurysms are a permanent, distensible disease that occurs due to local weakness of the wall of an artery. The cerebral aneurysm belongs to peripheral aneurysm, and refers to a tumor-like protrusion generated by local expansion of the cerebral artery wall, and the protruded aneurysm wall gradually thins and finally ruptures to bleed under the continuous impact of blood flow. The cerebral aneurysm rupture bleeding has acute morbidity, serious symptoms, no obvious aura, and high mortality and disability rate. The treatment of cerebral aneurysm is mainly by surgical clipping and endovascular interventional embolization. However, the surgical clamping trauma is large, the complications are many, and the operation and recovery time are long, so that the surgical clamping is not popular with doctors and patients. With the development and progress of minimally invasive endovascular interventional therapy technology, more and more cerebral aneurysm patients receive endovascular interventional therapy technology, and endovascular interventional embolization technology is gradually becoming the leading technology of cerebral aneurysm treatment.

Endovascular embolization of cerebral aneurysms is mainly embolized by implanting a releasable coil into the aneurysm through a microcatheter, so that the aneurysm cavity is occluded by thrombus and healed anatomically. For wide-neck aneurysms at arterial bifurcations, simple coils are not easy to embolize, and stents are often needed to assist embolization; at this time, the two stents need to be placed into the two main branches of the blood vessel, respectively, to perform the spring coil embolization treatment. The method comprises the following three steps: step one, a first bracket is placed; step two, a second bracket is arranged in a crossed manner; and thirdly, placing the microcatheter into the aneurysm through the two stents which are placed in a crossing way to carry out spring coil embolization. The operation of the steps is complicated, the influence range of the stent on the blood vessel is wide, and unnecessary branch vessel wall hyperplasia, stenosis and even occlusion can be caused; complicated procedures can also trigger thrombosis during the implantation procedure, causing unnecessary embolic complications. In addition, if only one stent is implanted, the mouth of the aneurysm cannot be closed well for safe treatment. The stent and the operation method are not safe and convenient, and the development of the stent which is simple to use and convenient to operate and is used for treating the aneurysm at the bifurcation of the cerebral artery is urgently needed.

The present application thus proposes a new stent device for occluding bifurcated aneurysms.

Disclosure of Invention

In view of the above-mentioned deficiencies of the prior art, the present invention provides a new stent device for occluding a bifurcated aneurysm, the technical problem to be solved being to facilitate placement of the stent device.

In order to solve the problems, the invention adopts the technical scheme that: a stent device for occluding a bifurcated aneurysm, the stent device comprising at least a stented section for placement against an interior wall of a blood vessel for stenting, a blood-penetrating section for placement at a bifurcation region of the blood vessel to allow blood flow at the bifurcation region, and a occluded section for placement at a neck of the bifurcated aneurysm for occluding the aneurysm, the stented, blood-penetrating and occluded sections extending in an axial direction of the stent device from a proximal end to a distal end, the occluded section being radially sized to expand relative to the blood-penetrating section so that the occluded section closely conforms to the neck of the bifurcated aneurysm.

Preferably, the support section, the blood penetrating section and the closing section have a mesh structure.

Preferably, the pore size of the mesh structure of the blood penetrating segment is larger than the pore size of the mesh structure of the support segment.

Preferably, the distal end opening of the closed section is closed and the proximal end opening of the proximal section is open.

Preferably, the closed section comprises an expansion structure radially dimensioned to expand relative to the blood penetrating section.

Preferably, the expandable structure comprises a plurality of arches.

Preferably, each of said arches has two free bases attached to the distal end of said blood-penetrating segment, and one of the bases of two adjacent arches is attached together to form a plurality of arch attachment portions.

Preferably, the number of the arch structures is more than three.

Preferably, the expandable structure comprises a plurality of approximately circular or approximately elliptical ring structures coupled to the distal end of the blood penetrating segment.

Preferably, the number of the approximate circular rings or the approximate elliptical ring structures is three or more.

Preferably, the closure segment further comprises a closure structure for closing the aneurysm.

Preferably, the closed structure is a criss-cross structure.

Preferably, the closure structure comprises a mesh structure woven from a flexible polymer braid.

Preferably, the stent device is provided with a developable marker thereon.

Preferably, the marker is a filament, surrounding the expanded structure.

Preferably, the stent device comprises a plurality of filaments, the filaments comprising undulating sections, at least some of the adjacent filaments being joined together by a plurality of junctions, at least some of the undulating sections of the plurality of filaments together forming the support section.

Preferably, the support section has adjacent filament unbonded slots.

Preferably, the stent device further comprises a proximal section having a pointed proximal end, the proximal section being formed by joining the proximal ends of the plurality of filaments.

Preferably, the filament further comprises straight segments, at least some of the straight segments of adjacent filaments being joined together, at least a portion of the straight segments of the plurality of filaments together constituting the blood-penetrating segment.

Preferably, the number of filaments is eight.

Preferably, the stent device comprises a pointed proximal end having a catch slot and a catch bore, wherein the catch slot extends from the catch bore from the distal end to the proximal end and has an opening at the proximal end.

The invention has the beneficial effects that: (1) the outward expansion of the closed section can increase the adhesive force to the blood vessel at the neck of the bifurcation aneurysm, and prevent the stent device from falling off; (2) the closed structure of the closed section can directly close the aneurysm, which is better than the treatment of bifurcation aneurysm by cross implantation of two stents, so that the spring ring embolism treatment is simpler and more convenient.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

Fig. 1 is a schematic structural view of a bifurcated aneurysm.

Fig. 2 is a schematic structural view of a preferred embodiment of the stent device for occluding bifurcated aneurysms provided by the present invention.

Fig. 3 is a schematic structural view of a closed section of the stent device shown in fig. 2.

Fig. 4 is a schematic view of the proximal, supporting and blood-penetrating segments of the stent device of fig. 2 being spread out in a plane.

Fig. 5 is another view of the stent device shown in fig. 2.

FIG. 6 is a schematic view of the configuration of the pointed proximal end of the proximal section of the stent device shown in FIG. 2.

FIG. 7 is a schematic structural view of another preferred embodiment of a closure segment of a stent device for occluding a bifurcated aneurysm of the present invention.

Detailed Description

The term "proximal" or similar directional terms as used herein should be understood as: the end of the device or component that is near the user (or handle) or remote from the target location of the vessel that needs to be treated; the term "distal" or similar directional terms as used herein should be understood as: the end of the device or component that is distal from the user (or handle) or near the target location of the vessel to be treated. The term "proximal portion" or "proximal segment" as used herein should be understood as: a portion of the device or component near or adjacent to the proximal end (not necessarily adjacent to the proximal end); the term "distal portion" or "distal segment" as used herein should be understood as: a portion of the device or component near or proximate to the distal end (not necessarily proximate to the distal end).

Figure 1 shows the structure of a bifurcated aneurysm.

As shown in fig. 1, the vessels at bifurcated aneurysm 200 include an input vessel 210, a first output vessel 220, and a second output vessel 230, bifurcated aneurysm 200 being located at the bifurcation of first output vessel 220 and second output vessel 230. The long-line arrows in the figure show the direction of blood flow, with a portion of the blood flow originating from the proximal end of the input vessel 210 flowing into the first output vessel 220 and another portion flowing into the second output vessel 230, while a portion of the blood flow flows into the bifurcated aneurysm 200, where it impinges on the aneurysm wall, thereby creating outward pressure and causing the aneurysm to expand. Generally, bifurcated aneurysm 200 morphologically has a distinct neck 201. In addition, the area indicated by the dashed line in the figure is the vessel bifurcation area of the bifurcated aneurysm 200, where the stent device is disposed to ensure the blood flow is unobstructed.

Fig. 2-3 illustrate a preferred embodiment of the stent device of the present invention for occluding bifurcated aneurysms.

As shown in fig. 2, in this embodiment, a stent device 100 for occluding a bifurcated aneurysm is deployed within a bifurcated aneurysm 200 and corresponding blood vessel. The stent device 100 comprises a proximal section 110, a supporting section 120, a blood penetrating section 130 and a closed section 140 which extend from the proximal end to the distal end in sequence, and the main form of the whole stent device 100 is a mesh structure formed by filaments. The support section 120, which has the longest length, is disposed inside the input blood vessel 210 and fits the inner wall of the input blood vessel 210, and mainly functions to support and determine the position and orientation of the entire stent device. The proximal section 110 is located at the proximal end of the strut section 120. since the primary form of the strut section 120 is a mesh structure of filaments, the proximal section 110 is the combined portion of the proximal ends of the filaments as they are manufactured. The blood-penetrating segment 130 is disposed at the vessel bifurcation area of the bifurcated aneurysm 200, and the mesh size of the blood-penetrating segment 130 is larger than that of the strut segment 120 for the purpose of smooth blood flow. The occlusive segment 140, which is located at the distal end of the overall stent device, is disposed at the neck 201 of the bifurcated aneurysm 200 and serves primarily to occlude the bifurcated aneurysm 200, i.e., to occlude the coil embolized into the bifurcated aneurysm 200 within the aneurysm. To function as a closure coil, the distal opening of the closed section 140 is closed, while the proximal opening of the proximal section 110 is open. As can be seen in FIG. 2, the radial dimension of the closed section 140 is configured to expand relative to the blood-penetrating segment 130 in order to provide a snug fit of the closed section 140 against the neck 201 of the bifurcated aneurysm 200. Because the distal end of the closed section 140 has a radial dimension that is greater than the opening dimension of the neck 201 of the bifurcated aneurysm 200, the stent device is less likely to dislodge from the bifurcated aneurysm 200 and corresponding vessel after the stent device has been placed within the bifurcated aneurysm 200 and corresponding vessel. It should be noted that the proximal section 110, the support section 120, the blood penetrating section 130 and the closing section 140 of the stent device 100 shown in fig. 2 are not structurally distinct boundaries, and these parts are so named depending on their approximate location and role in the vessel.

Fig. 3 shows the structure of the closing segment 140 from another perspective.

As shown in fig. 3, the closing section 140 includes an expanding structure 141 and a closing structure 142. The expandable structure 141 is disposed at the neck 201 of the bifurcated aneurysm 200 and is radially sized to expand relative to the blood-penetrating segment 130, primarily to prevent the occlusive segment 140 from exiting the bifurcated aneurysm 200. In this embodiment, the expandable structure 141 comprises four arches of filaments, each arch having two free bases, both of which are bonded to the filaments at the distal end of the blood-penetrating segment 130, and one of the bases of two adjacent arches is bonded together to form four arch bonds 143. The distal ends of the four arches are inclined away from the central axis to form an expanded configuration. The primary purpose of the closure structure 142 is to close the opening of the expandable structure 141 to enclose the coils embolized into the bifurcated aneurysm 200 within the aneurysm. In this embodiment, the closure structure 142 is a criss-cross structure of filaments, the criss-cross structure has four free ends, and the four free ends are respectively combined with the four arch-shaped structure combining parts 143, so that the closure structure 142 has the function of closing the coil and the aneurysm.

As a variant of the above-described construction, the number of arches can obviously also be two, three, five or more, preferably more than three, and can be set according to the actual requirements. The arch structures can be in the shape of circular arcs, rounded polygons or other irregular shapes, and the free base parts of adjacent arch structures can be combined together or separated. The four free ends of the cruciform structure may also be attached to other portions of the dome and even to filaments at the distal end of the blood-penetrating segment. The closed sections are not necessarily in the form of arches or criss-cross structures, as will be further explained later.

Figure 4 shows the proximal section, the support section and the blood penetrating section spread into a planar configuration.

As shown in FIG. 4, proximal section 110, support section 120, and blood-penetrating section 130 are all a mesh structure of filaments. In this particular embodiment, the proximal segment 110, the strut segment 120, and the blood penetrating segment 130 are comprised of a total of eight filaments, a first filament 101, a second filament 102, a third filament 103, a fourth filament 104, a fifth filament 105, a sixth filament 106, a seventh filament 107, and an eighth filament 108, respectively. The eight filaments each include a wavy section and a straight section extending in a direction substantially parallel to the central axis of the stent device. Wherein the first filament 101 and the second filament 102 are joined together in a plurality of bonds and form a mesh structure, while the proximal ends of the first filament 101 and the second filament 102 are joined to form a pointed proximal end of the overall stent device. The third filament 103 is connected to the other side of the first filament 101 by a multi-junction manner, the fifth filament 105 is connected to the other side of the third filament 103 by a multi-junction manner, the seventh filament 107 is connected to the other side of the fifth filament 105 by a multi-junction manner, the fourth filament 104 is connected to the other side of the second filament 102 by a multi-junction manner, the sixth filament 106 is connected to the other side of the fourth filament 104 by a multi-junction manner, and the eighth filament 108 is connected to the other side of the sixth filament 106 by a multi-junction manner. The proximal end of the seventh filament 107 and the eighth filament 108, counted from the sharp proximal end of the entire stent device (proximal junction of the first filament 101 and the second filament 102), constitute the proximal section 110 of the entire stent device; the distal ends of the undulating sections of the eight filaments from the proximal ends of the seventh filament 107 and the eighth filament 108 form the support section 120 of the overall stent device. In addition, the eight filaments include straight segments, with the straight segments of the first filament 101 and the third filament 103 being joined together, the straight segments of the fifth filament 105 and the seventh filament 107 being joined together, the straight segments of the second filament 102 and the fourth filament 104 being joined together, and the straight segments of the sixth filament 106 and the eighth filament 108 being joined together to form four distal ends, to which the four arch-shaped structure junctions 143 mentioned above are joined. With this arrangement, the mesh of the blood-penetrating segment 130 has a larger aperture than that of the supporting segment 120, so that the blood can flow smoothly through the bifurcated region of the blood vessel.

Fig. 5 shows the connection relationship of the seventh and eighth filars.

As shown in fig. 5, the seventh filament 107 and the eighth filament 108 are not bonded, i.e., the support section 120 has an open channel, which makes the support section 120 more flexible to prevent undesirable compression of the vessel inner wall.

While figures 4 and 5 and the above illustrate one configuration of proximal section 110, support section 120 and blood-penetrating section 130, it will be apparent that the number of filaments may be other and arranged as desired. The wavy section and the straight section of the filament can be in other shapes as long as the aperture of the blood penetrating section is larger than that of the supporting section.

Fig. 6 shows the configuration of the pointed proximal end of the stent device.

As shown in fig. 6, the pointed proximal end of the stent device has a catch 111 and a catch hole 112, wherein the catch 111 extends proximally from the distal end of the catch hole 112 and has an opening at the proximal end. The purpose of the bayonet slots 111 and bayonet holes 112 is to connect the stent device to a delivery device (e.g., a delivery rod or microcatheter, etc.). The stent device is disengaged (e.g., electrolytically disengaged) from the delivery device after reaching the target location.

With respect to the fabrication of the stent device shown in fig. 2-6, separate filaments may be fabricated and then bonded together. For example, the first filament 101, the second filament 102, the third filament 103, the fourth filament 104, the fifth filament 105, the sixth filament 106, the seventh filament 107, and the eighth filament 108 are first manufactured, and then eight filaments are combined (e.g., by welding). The manufacture may also be performed by direct cutting of the tube, for example by laser cutting, into the desired mesh shape, in which case the first filament 101, the second filament 102, the third filament 103, the fourth filament 104, the fifth filament 105, the sixth filament 106, the seventh filament 107, the eighth filament 108 do not have clear boundaries from the point of view of the manufacturing process. Thus, the various filaments referred to herein may be understood as a portion of an integrally formed component, and should not be construed restrictively from the perspective of the manufacturing process. The manufacturing may also be a combination of the two ways, for example, by laser cutting the tubular to the shape of the proximal section 110, the support section 120, the blood penetrating section 130, and then welding the expanded 141 and closed 142 structures of the closed section 140 to the distal end of the blood penetrating section 130.

The stent device is preferably made of a shape memory alloy, such as a nickel-titanium based shape memory alloy, e.g., titanium nickel copper, titanium nickel iron, titanium nickel chromium, and the like. In addition, markers may be provided at a plurality of positions of the stent device. The marker is used for displaying the position of the stent device under the radiation (such as X-ray), and the material of the marker can be selected from metals or metal alloys with better biocompatibility or stability, such as platinum group metals (such as platinum iridium alloy), gold and the like, or polymer materials added with developing materials (such as barium salt (BaSO4 and the like), bismuth salt (BiOCl and the like). The tag may be of any suitable shape and is bonded to the stent device by welding, adhesive or other attachment means. For example, markers may be placed on the proximal, middle, and distal ends of the stent device to allow real-time visualization of the position of the entire stent device during the procedure. As another example, as shown in FIG. 3, the marker 144 is a filament that surrounds the expandable structure 141.

The stent device is delivered to the bifurcation aneurysm and the corresponding blood vessel through a micro-catheter and a micro-guide wire. Firstly, a micro guide wire is sent into the bifurcation aneurysm along an input blood vessel of the bifurcation aneurysm, then a micro catheter with a built-in stent device is sent to the bifurcation aneurysm along the micro guide wire, then the far end of the stent device is pushed forward, and whether the position is correct or not is judged according to a marker of the stent device; the microcatheter is slowly withdrawn and the stent device is gradually released at the neck of the bifurcated artery. The spring wire is then threaded along the microcatheter and through the closure structure of the closed section of the stent device into the aneurysm, and the spring wire entering the aneurysm automatically crimps into a coil and becomes enclosed within the aneurysm. Delivery stent devices and coils are well known in the art and will not be described in detail herein.

Fig. 7 shows the structure of another preferred embodiment of the closed section of the stent device.

As shown in FIG. 7, the closing section 140 in this embodiment includes an expanding structure 141 and a closing structure 142. The expandable structure 141 is disposed at the neck 201 of the bifurcated aneurysm 200 and is radially sized to expand relative to the blood-penetrating segment 130, primarily to prevent the occlusive segment 140 from exiting the bifurcated aneurysm 200. The expandable structure 141 comprises four approximately elliptical ring structures of filaments bonded to the filaments at the distal end of the blood-penetrating segment 130. The distal ends of the four near-elliptical ring structures are angled away from the central axis to form an expanded structure. Closure structure 142 includes a mesh structure woven from a flexible polymer braid (e.g., polyimide filaments). The mesh structure may also be radially compressed to extend into the neck of the bifurcated aneurysm when the stent device is placed in a microcatheter for delivery. The network structure may also be developable, for example, by adding a developing material (e.g., barium salt (BaSO4, etc.), bismuth salt (BiOCl, etc.) to the polymer.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims (10)

1. A stent device for occluding a bifurcated aneurysm, the stent device comprising at least a supporting section for placement on an inner wall of a blood vessel for supporting, a blood penetrating section for placement at a bifurcation region of the blood vessel to allow blood to flow at the bifurcation region of the blood vessel, and a closing section for placement at a neck of the bifurcated aneurysm for occluding the aneurysm, the supporting section, the blood penetrating section, and the closing section extending from a proximal end to a distal end in an axial direction of the stent device, the closing section being radially sized to expand relative to the blood penetrating section so that the closing section closely conforms to the neck of the bifurcated aneurysm.

2. The stent device for occluding a bifurcated aneurysm of claim 1, wherein the supporting, blood-penetrating, and occluding segments have a mesh structure.

3. The stent device for occluding bifurcated aneurysms of claim 2, wherein the mesh structure of the blood penetrating segment has larger pore sizes than the mesh structure of the support segment.

4. The stent device for occluding a bifurcated aneurysm of claim 1, wherein the distal opening of the occlusive segment is closed and the proximal opening of the proximal segment is open.

5. The stent device for occluding a bifurcated aneurysm of claim 1, wherein the occluding segment includes an expansion structure radially sized to expand relative to the blood penetrating segment.

6. The stent device for occluding a bifurcated aneurysm of claim 5, wherein the expandable structure comprises a plurality of arches.

7. The stent device for occluding a bifurcated aneurysm of claim 6, wherein each of said arches has two free bases joined to the distal end of said blood-penetrating segment, and wherein one of the bases of two adjacent arches is joined together to form a plurality of arch-shaped junction portions.

8. The stent device for occluding a bifurcated aneurysm of claim 6, wherein the number of arches is three or more.

9. The stent device for occluding a bifurcated aneurysm of claim 5, wherein the expandable structure comprises a plurality of approximately circular or approximately elliptical ring structures coupled to the distal end of the blood-penetrating segment.

10. The stent device for occluding a bifurcated aneurysm of claim 9, wherein the number of said approximately circular or approximately elliptical ring structures is three or more.

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