Thin film medical device and delivery system
The present invention relates to a delivery system for an intraluminal thin film medical device particularly well suited for occlusion of an aneurysm, vessel side branch or dissection of a body lumen or duct, such as an artery or vein. The delivery system has an outer sheath attached along the distal end of a relatively long and flexible tubular shaft. The outer sheath is capable of constraining the thin film medical device in a longitudinally stretched position, and subsequently being retracted relative to the flexible tubular shaft to release the thin film medical device from the constrained longitudinally stretched position. The delivery system may additionally have a mechanical expansion catheter substantially coaxial too, and slideably engaged within, the outer sheath and an inner lumen substantially coaxial to the outer sheath and incorporated into the flexible tubular shaft.
1. A delivery system for deploying a tubular thin film and a mechanically expandable stent, the system includes the tubular thin film and the stent prior to their deployment, the tubular thin film including a self-supporting biocompatible metal or pseudometals of a thickness from between 1 micron and 250 microns, and further comprising:
a long and flexible tubular shaft having proximal and distal ends and defining an inner lumen there through;
a retractable, tubular outer sheath attached along the distal end of the long and flexible tubular shaft and configured to extend along the length of the tubular thin film, the outer sheath being configured to constrain the tubular thin film in a longitudinally stretched position having a constrained length L 1 and a constrained diameter D 1 prior to delivery completion, and subsequently being retracted relative to the flexible tubular shaft to release the thin film from the constrained longitudinally stretched position to a longitudinally relaxed position having a length L 2 and a diameter D 2 , wherein L 1 is longer than L 2 and D 1 is smaller than D 2 ;
a mechanical expansion catheter substantially coaxial to, and slideably engaged within, the outer sheath, the mechanical expansion catheter comprising the mechanically expandable stent coaxially mounted on a radially expandable expansion member, the expansion member being configured to mechanically expand the expandable stent by generation of a radially directed force; and
a secondary sheath disposed next to the stent to surround the stent, the secondary sheath comprising a composite structure incorporating an inner layer, an outer layer, and a middle layer, such that the inner layer and outer layer help to prevent the stent from becoming too imbedded into the secondary sheath prior to stent deployment, the secondary sheath being of a smaller diameter than the outer sheath and coaxial thereto with the thin film surrounding the secondary sheath, the secondary sheath serving to hold the stent in a constrained position.
2. The delivery system of claim 1 wherein the outer sheath comprises a polymeric material.
3. The delivery system of claim 2 wherein the polymeric material comprises a polymer from the group consisting of polyethylene, polyamide, polyurethane, and polytetrafluroethylene.
4. The delivery system of claim 2 wherein the polymeric material comprises a polymer from the group consisting of polycarbonate and polyimide.
5. The delivery system of claim 1 wherein the outer sheath has reinforcement material.
6. The delivery system of claim 5 wherein the reinforcement material is a metallic braid integrated into the outer sheath.
7. The delivery system of claim 5 wherein the reinforcement material is a high tensile strength polymeric braid woven into the outer sheath.
8. The delivery system of claim 1 wherein the long and flexible tubular shaft comprises a multi-layered polymeric material.
9. The delivery system of claim 1 wherein the long and flexible tubular shaft comprises a reinforcement material.
10. The delivery system of claim 9 wherein the reinforcement material is a metallic braid integrated into the inner lumen.
11. The delivery system of claim 9 wherein the reinforcement material is a high tensile strength polymeric braid woven into the inner lumen.