Vertebral artery stent and conveying system thereof

Abstract

The invention discloses a vertebral artery stent and a conveying system thereof. The vertebral artery stent is a composite braided stent; the diameter of the two ends of the stent is larger than thatof a stent main body, the near end is in an opening shape with the diameter gradually increased, and the far end is spherical or barrel-shaped. The stent is very suitable for treating artery blood vessel bifurcation lesions, especially vertebral artery initial stenosis, the long-term fracture rate of the stent can be greatly reduced, and therefore restenosis can be effectively reduced; the designof preventing stent displacement is achieved, and the requirement for vertebral artery stenosis in clinic can be met. According to the stent conveying system, the stent is released from the near end to ensure accurate positioning, part of the released stent can be repositioned and then released after being withdrawn from the conveying system, and the operation difficulty and risk are greatly reduced.

Description

technical field [0001] The invention relates to a vertebral artery stent and a delivery system thereof, belonging to the technical field of medical appliances. Background technique [0002] Stroke is a refractory disease that seriously endangers human health and life safety. According to statistics, there are 3 million stroke patients in China every year, and 1.2 million stroke patients die every year. There are 12 million surviving stroke patients, 6 million of whom have lost their labor force and are unable to take care of themselves to varying degrees. The most common type of stroke is atherosclerotic cerebral infarction. Cerebral atherosclerosis mainly occurs at arterial bifurcations and turning points, such as the origin of the vertebral artery and the cranial entry, the origin of the internal carotid artery, the bifurcation of the middle cerebral artery, and the origin of the basilar artery. Atherosclerotic stenosis can occur in the entire vertebrobasilar artery, but...

AI Technical Summary

Problems solved by technology

In addition to the high long-term fracture rate, the clinically used vertebral artery stents have the following defects: first, the straight cylindrical stents are poorly adhered to the wall at the opening of the vertebral artery, which cannot prevent the plaque from falling off at this part; Continuous stimulation of the wall, causing intimal hyperplasia, prone to in-stent restenosis

Although this type of operation improves the adhering of the stent to the wall at the opening of the vertebral artery, the forcibly deformed stent has a high rate of long-term fracture, which will also bring risks to the patient.

Second, the distal end of the straight cylindrical stent is not designed to inhibit the migration of the stent. It is often reported that the stent migrates to the subclavian artery connected to the vertebral artery, causing thrombus and in-stent restenosis, which may endanger the life of the patient in severe cases.

There are several intracranial stents designed with bell-shaped ends at both ends, such as Codman’s Enterprise stent and Microvention’s LVIS stent, but the long-term restenosis of such stents is likely to occur at the bell mouth. The reason is that the horn port and the LVIS stent The blood vessel is a line contact or even a point contact with a very small contact surface. The radial force and friction of the stent on the vessel wall are too large, so it is easy to accelerate intimal hyperplasia and lead to restenosis

Third, after most of this type of nickel-titanium alloy stent is released, the rest of the stent compressed in the delivery catheter will bounce out, causing the stent to deviate from the ideal position, which cannot bring the best clinical effect. Stent delivery systems do not solve the problem of stent bounce

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