Super-smooth nickel-titanium alloy intracranial vascular stent with micro-nano structure

A technology of intracranial blood vessels and micro-nano structures, applied in the field of medical devices, can solve the problems of non-adhesion, protruding into aneurysms, and poor adhesion, so as to prevent crushing or collapse, promote vascular endothelialization, and adherence good effect

Active Publication Date: 2021-03-23
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, intracranial blood vessels are tortuous and complex, and intracranial aneurysms are more likely to occur at the bifurcation of the cerebral base arterial ring and its main branches, and there are often different degrees of curvature, and the diameter of the blood vessels may also be inconsistent
In addition, the size of intracranial aneurysms varies greatly, and interventional treatment for some wide-necked and fusiform aneurysms is still very difficult
For existing products, intracranial stent structures are roughly divided into two types: open-loop and closed-loop. Each structural stent has its own advantages and disadvantages. For blood vessels with high curvature, the bending performance of open-loop stents is better than that of closed-loop stents. Avoid discounting, ovalization, etc. Since the stent is not connected to the connecting rod in the open-loop part, the stent has better adaptability to uneven blood vessels, but the outer gap will increase with the curvature, resulting in the risk of the coil coming out; In addition, for open-loop structural stents with long unit spans, the open-loop part may cause non-adherence or protrude into the aneurysm, causing thrombosis and other problems
Although the closed-loop structure stent can provide high support performance, due to its overall continuity and high rigidity, the stent is relatively hard as a whole, and the wall-attachment is poor after implantation, and even displacement occurs, eventually causing complications such as thrombosis and restenosis
[0004] Most of the existing products are designed with a unified structure. For complex intracranial vessels, especially those with large curvature and variable vessel diameters, there is little coordination between compliance / adherence and support performance, and it is difficult to over-embolize coils. The wide-necked, fusiform aneurysm neck provides local support, but does not solve the problems of open-loop structural support performance, gaps, and non-adherence

Method used

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  • Super-smooth nickel-titanium alloy intracranial vascular stent with micro-nano structure
  • Super-smooth nickel-titanium alloy intracranial vascular stent with micro-nano structure
  • Super-smooth nickel-titanium alloy intracranial vascular stent with micro-nano structure

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] In this example, a super-compliant nickel-titanium alloy intracranial vascular stent with a micro-nano structure is designed. The middle part of the design is locally reinforced with a closed-loop structure, and the length is 2.25 mm; the open-loop structure accounts for 30% of the surface area of ​​the entire intracranial vascular stent. ; The second V-shaped unit 2 wire width is 0.05mm, the first V-shaped unit 1 wire width is 0.0367mm, the connecting rod (b) height a is 0.05mm, the width b is 0.05mm, and the connecting rod (c) height c is 0.06mm, width d is 0.0857mm. The ratio of the length dimension to the width dimension of the first V-shaped unit 1 is 0.84, and the ratio of the height dimension to the width dimension of the second V-shaped unit 2 is 0.6-0.7.

[0045] Such as image 3 As shown, the plane unfolded cutting diagram of the intracranial vascular stent. According to the design drawings, the final intracranial vascular stent can be prepared by laser cutt...

Embodiment 2

[0047] In this embodiment, a three-point bending test is performed on the stent processed in Example 1 to characterize the flexibility of the stent. The three-point bending test equipment consists of two lower fixed support parts (parallel cylinders with a diameter of 4 mm) and an upper loading part (a cylinder with a diameter of 4 mm). The fixed-span three-point bending method is adopted, and the span of the lower fixed support part is set to 20mm. Proceed as follows:

[0048] a) Assembly lofting: place the sample perpendicular to the fixed support parts, assemble the loading part parallel to the fixed support parts, and make it in the middle of the two fixed support parts.

[0049] b) Start-up test: load is applied at a constant rate of 0.05 mm / s up to a predetermined maximum deflection of 4.5 mm.

[0050] c) Record whether the sample exhibits sufficiently uniform bending throughout the test, and plot the load versus deflection curve.

[0051] Such as Figure 5 Test resu...

Embodiment 3

[0053] In this embodiment, during the process of release and compression, the relationship between the radial support force of the stent processed in Example 1 and the diameter of the stent was measured to characterize the support performance of the stent. Using radial crimping method and plate method respectively:

[0054] 1. Radial crimping method:

[0055] a) Place the bracket into the device, and the initial aperture of the device is set to 7mm;

[0056] b) Reduce the diameter of the stent to 0.5mm at a rate of 0.0156mm / s;

[0057] c) Then the aperture increases at a rate of 0.0156mm / s, and the bracket is slowly unloaded to 4.5mm;

[0058] d) During the stent crimping process, the relationship between radial force and stent diameter is recorded.

[0059] 2. Plate method:

[0060] a) Place the bracket between the two plates, and make it in the center of the component, and adjust the pressure head to just stick to the surface of the bracket;

[0061] b) Apply a load at ...

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Abstract

The invention relates to a super-smooth nickel-titanium alloy intracranial vascular stent with a micro-nano structure, can be used for assisting a spring ring embolism in treating intracranial aneurysm, and belongs to the field of medical instruments. An intracranial vascular stent body is composed of an open-loop structure and a closed-loop structure; the open-loop structure is formed by connecting first V-shaped units distributed in the circumferential direction and second V-shaped units distributed in the circumferential direction through connecting rods; the closed-loop structure is formedby connecting second V-shaped units distributed in the circumferential direction through connecting rods; the number ratio of the open-loop free ends of the second V-shaped units to the open-loop free ends of the first V-shaped units is 1 to 2; and the open-loop structure enhances the flexibility and adherence of the stent, and the closed-loop structure provides supporting performance. The intracranial vascular stent has super-smooth performance, can be suitable for assisting spring ring embolism in treating aneurysms (such as large-curvature blood vessels and variable-diameter blood vessels)at intracranial complex blood vessels, and achieves a good adherence effect.

Description

technical field [0001] The invention relates to a super-compliant nickel-titanium alloy intracranial vascular stent with a micro-nano structure, which can be used to assist coil embolization in the treatment of intracranial aneurysms, and belongs to the field of medical devices. Background technique [0002] Intracranial aneurysm is the abnormal bulging of the intracranial artery wall due to congenital abnormal defects of blood vessels or acquired lesion trauma and other factors, and is the primary cause of subarachnoid hemorrhage. Compared with aneurysm clipping and ligation, endovascular interventional therapy is safer and more adaptable. It is currently the main intracranial aneurysm treatment method. Aneurysm occlusion can be achieved by intracranial vascular stent-assisted coil embolization . [0003] However, intracranial blood vessels are tortuous and complex, and intracranial aneurysms are more likely to occur at the bifurcation of the arterial ring at the base of t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): A61F2/90
CPCA61F2/90A61F2310/00071A61F2310/00023
Inventor 张兴燕阳阳郭峰韩日峥杨锐
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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