Modified delivery device for coated medical devices
View Patent ↗Medical devices, and in particular implantable medical devices, including self-expanding stents, may be coated to minimize or substantially eliminate a biological organism's reaction to the introduction of the medical device to the organism. The devices utilized to deliver the implantable medical devices may be modified to reduce the potential for damaging the implantable medical device during deployment.
1. A delivery system for coated medical devices comprising:
a substantially tubular shaft having a proximal end configured for increased flexibility, a distal end, a guidewire lumen extending between the proximal and distal ends, a tapered distal tip at the distal end of the shaft and a stop mounted to the shaft proximal to the distal tip and a stent bed region positioned between the stop and the distal tip upon which a coated, self-expanding stent is positioned, the self-expanding stent comprising a tubular member having a plurality of adjacent hoops, including a plurality of longitudinal struts and a plurality of loops, and a plurality of bridges connecting adjacent hoops, the stent bed region including a textured surface comprising one or more raised elements protruding from the substantially tubular shaft and arranged in a pattern corresponding to the gaps between the plurality of bridges comprising the self-expanding stent for preventing longitudinal movement of the coated, self-expanding stent along the shaft; and
a substantially tubular sheath defining an interior volume and coaxially positioned over the tubular shaft and the coated, self-expanding stent, the substantially tubular sheath having a distal end and a proximal end, the distal end having an increased diameter in the distal end proximate the stent bed region relative to the diameter of the proximal end, the substantially tubular sheath also comprising a compsite structure having an inner layer formed from a low coefficient of friction in material, an outer layer and a wire reinforcement layer between the inner layer and the outer layer, the height of the one or more raised elements is greater than the difference in radius between the outside radius of the shaft and the inside radius of the sheath minus the wall thickness of the stent and less than the difference between the inside radius of the sheath and the outside radius of the shaft, the stop comprising a radio-opaque material and configured to make contact with the self-expanding stent and no frictional contact with the substantially tubular sheath.
2. The delivery system for coated medical devices according to claim 1 , wherein the one or more raised elements comprises raised substantially rectangular nubs formed on the surface of the substantially tubular shaft.