Implant deployment apparatus

Abstract

A delivery system including a restraining member maintains a collapsed implant in its collapsed state for delivery through a small passageway to a desired site in a mammalian body. Once the implant is positioned at the desired site, the restraining member is released so that the stent may expand or be expanded to its expanded state. In a preferred embodiment, the restraining member comprises a sheet of material that surrounds at least a portion of the collapsed stent. Portions of the restraining member are releasably coupled to one another with a low profile thread-like member or suture.

Description

BACKGROUND OF THE INVENTION[0001]1. Technical Field[0002]This invention relates generally to implants for repairing ducts and passageways in the body. More specifically, the invention relates to implant deployment apparatus.[0003]2. Background Art[0004]Treatment or isolation of vascular aneurysms or of vessel walls which have been thickened or thinned by disease has traditionally been performed via surgical bypassing with vascular grafts. Shortcomings of this procedure include the morbidity and mortality associated with surgery, long recovery times after surgery, and the high incidence of repeat intervention needed due to limitations of the graft or of the procedure.[0005]Vessels thickened by disease may be treated less invasively with stents which mechanically hold vessels open. In some instances, stents may be used subsequent to or as an adjunct to a balloon angioplasty procedure. Stents also have been described in conjunction with grafts where the graft is intended to provide a g...

AI Technical Summary

Benefits of technology

The present invention is about a delivery system for an implant like a stent or stent-graft. This system includes a sheet of material that can be extended around a collapsed implant to form a tubular member to keep it in a collapsed state during delivery. The sheet is made of a thin material that does not significantly contribute to the structure of the delivery assembly. This design allows for a smooth interface between the collapsed stent and a vessel lumen and helps deliver the device to remote sites and small tortuous vasculature. The sheet can also be coupled together to maintain the implant in its collapsed state. The invention also includes an assembly of a stent and a restraining member, where the restraining member is a sheet of material that is releasably coupled to the stent to keep it in its collapsed state. The sheet can be coupled with a filament or thread-like member, and multiple restraining members or coupling members can be used to reduce deployment time and improve accuracy.

Problems solved by technology

Shortcomings of this procedure include the morbidity and mortality associated with surgery, long recovery times after surgery, and the high incidence of repeat intervention needed due to limitations of the graft or of the procedure.

Generally, the mechanisms described above involve a number of components that may increase operational complexity.

In addition, the size and mechanical properties of these mechanisms may limit deliverability of implants in small vessels.

Delivery accuracy also may be a problem as discussed.

The diameter of conventional telescoping stent sheaths may contribute to undesirable friction with the delivery catheter as the sheath is pulled from the stent and over a push rod during deployment.

This may make deployment accuracy difficult to control.

Push rods, which are used to push the stent through the delivery catheter and which typically have a length of up to about 100 cm, also may contribute to undesirable friction with the catheter.

This problem may be exacerbated where the catheter bends along its path in the vasculature.

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