Stent with sheath and metal wire and methods

Abstract

A stent assembly includes a stent and a fiber mesh sleeve covering the stent. A wire runs along the stent over the sleeve and fastened to the stent at multiple points so as to attach the sleeve to the stent. Methods of making the stent assembly are included.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 11 / 920,972, filed Nov. 23, 2007, now pending, which is a national stage of PCT / IB2006 / 051874, filed May 24, 2006, now expired, which claims the benefit of U.S. Provisional Application Nos. 60 / 683,788, filed on May 24, 2005; 60 / 716,100, filed on Sep. 12, 2005; and 60 / 742,460, filed Dec. 5, 2005. The entire contents of each of these prior applications is incorporated herein in its entirety by express reference thereto.FIELD OF THE INVENTION[0002]Carotid stent assemblies and methods are provided for treatment and / or support via body lumens and in other hollow organs.BACKGROUND OF THE INVENTION[0003]A stenosis is a stricture of a canal or duct. In the context of the vascular system a stenosis is a narrowing of the lumen of a blood vessel. A stenosis can severely restrict blood flow and promote thrombosis which can lead to myocardial infarction or stroke, for example. A com...

AI Technical Summary

Benefits of technology

This patent is about a stent that has tiny openings to help prevent the growth of blood clots in blood vessels. The stent has a porous structure that allows endothelial cells (a type of cell found in blood vessels) to easily move through the structure and grow on it. This can help to keep the blood vessel clean and free of clots. The stent can also be used with a drug-eluting stent or a bare metal stent, depending on the needs of the patient. Overall, this stent design helps to improve blood flow and reduce the risk of complications in patients with blockages in their blood vessels.

Problems solved by technology

A stenosis can severely restrict blood flow and promote thrombosis which can lead to myocardial infarction or stroke, for example.

However, these procedures frequently injure the blood vessel.

One problem with stenting according to this widely used procedure, however, is that as the stent expands, it engages relatively brittle plaque lining the arterial tissues surrounding the stent, not the arterial tissue itself.

In doing so, the expanding stent cracks the plaque to produce debris.

This debris, in an untended condition, then enters the blood stream and occasionally injures the patient further by causing a vessel blockage downstream.

This debris creating effect is especially problematic when stenting in the carotid arteries, where the downstream blood flow leads directly to the brain and debris can cause strokes.

In coronary arteries, debris is particularly dangerous because it can lead to heart attacks.

There are a number of drawbacks with using these embolic shower protection devices as they exist currently.

One drawback is that they often encompass using another device, in addition to the balloon catheter which must be inserted into the patient, adding time and potential danger to the procedure.

Another drawback is that the protection device must be downstream of the stent location, therefore, some additional stretch of vasculature must be available in order to properly position the protection device.

Yet another drawback is that the embolic shower protection device is removed at the conclusion of the stenting procedure and therefore does not provide any protection after that point, despite the fact that post procedure debris can become potentially dislodged as a result of the procedure.

Yet another drawback is that the embolic shower protection device is placed some distance from the stent, thus possibly leaving some close side branches unprotected.

However, one drawback with these stents is that pharmaceuticals are placed only on the stent struts, which cover only a small portion of the blood vessel's wall, and they do not cover the apertures in the stent.

Since some pharmaceuticals are comprised of large molecules, with a very high molecular weight, and / or complicated and / or wide stereochemistry, and which have limited diffusion capabilities, there is a large area of tissue which is not effectively treated.

Another drawback of current drug eluting stents is that an attempts to overcome the diffusion issues, an excessive amount of drug must be eluted in the hopes that it will permeate to the target tissue.

In some cases, this causes undesirable overdosing of the tissue areas closest to the stent struts in addition to the added expense of using copious amounts of the drug.

Furthermore, there are design limits which prevent increasing the amount of drug embedded and thus, eluted from the stent.

Longer administration period of anticoagulant drugs like Plavix® is needed, with additional cost and more side effects for the patients.

Even if the patient is being treated with anticoagulants, there is a very high risk that the platelets will stick to the exposed stent and cause clotting.

This phenomenon may lead to a total occlusion of the blood vessel and to an immediate myocardial infarction.

Drug eluting stents are more susceptible to such incidences since the conformity and the integrity of the endothelial cells covering the polymer is not as good as when they are covering a bare metal stent.

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