Expandable scaffold with cutting elements mounted thereto

Abstract

A medical device assembly for incising a stenosis in a blood vessel which includes an incising device, a tubular sheath, and a catheter having an inflatable balloon mounted thereon. The incising device includes a self-expanding scaffold having a plurality of cutting elements projecting radially outward therefrom, and an elongate member extending proximally from the self-expanding scaffold to be manipulated by a user. The self-expanding scaffold is positionable in the lumen of the sheath in a contracted configuration and deployed out of the lumen of the sheath to permit the self-expanding scaffold to expand to an expanded configuration. The inflatable balloon of the catheter is configured to be advanced distally into an interior of the self-expanding scaffold through a proximal opening of the self-expanding scaffold, and inflation of the inflatable balloon urges the cutting elements radially outward to incise a stenosis.

What is claimed is: 
     
         1 . A medical device assembly for incising a stenosis in a blood vessel, the medical device assembly comprising:
 a self-expanding scaffold configured to be expandable from a first contracted configuration to a second expanded configuration, the self-expanding scaffold being biased toward the second expanded configuration;   a cutting element secured to the self-expanding scaffold and extending radially outward therefrom;   a sheath having a lumen therein, the self-expanding scaffold positionable in the lumen of the sheath in the first contracted configuration; and   an elongate member extending proximally from the self-expanding scaffold through the lumen of the sheath;   wherein the self-expanding scaffold is constrained in the lumen of the sheath to maintain the self-expanding scaffold in the first contracted configuration and deployed out of the lumen of the sheath to permit the self-expanding scaffold to expand to the second expanded configuration.   
     
     
         2 . The medical device assembly of  claim 1 , wherein the self-expanding scaffold includes a distal tip including a guidewire lumen for receiving a guidewire therethrough, the distal tip being arranged coaxially with the self-expanding scaffold. 
     
     
         3 . The medical device assembly of  claim 2 , wherein the self-expanding scaffold is advanceable over a guidewire positioned along an exterior surface of the elongate member and extending through the guidewire lumen of the distal tip. 
     
     
         4 . The medical device assembly of  claim 3 , wherein the self-expanding scaffold includes a proximal opening sized and configured to advance an inflatable balloon mounted on a catheter into an interior of the self-expanding scaffold. 
     
     
         5 . The medical device assembly of  claim 1 , wherein the self-expanding scaffold includes a plurality of helically arranged wires crossing at cross-over points, wherein the cutting element is secured to the scaffold at at least one of the cross-over points. 
     
     
         6 . The medical device assembly of  claim 5 , wherein the plurality of helically arranged wires converge at and are secured to a distal tip of the self-expanding scaffold. 
     
     
         7 . The medical device assembly of  claim 6 , wherein the distal tip includes a guidewire lumen arranged coaxially with the self-expanding scaffold. 
     
     
         8 . The medical device assembly of  claim 1 , wherein the self-expanding scaffold includes a plurality of helically arranged wires extending from a distal end of the elongate member to a distal tip of the self-expanding scaffold. 
     
     
         9 . The medical device assembly of  claim 8 , wherein at least one end of the cutting element is slidable relative to the plurality of helically arranged wires as the self-expanding scaffold expands from the first contracted configuration to the second expanded configuration. 
     
     
         10 . The medical device assembly of  claim 1 :
 wherein the cutting element is a first cutting element;   wherein the medical device assembly further comprises a second cutting element; and   wherein the first cutting element is offset longitudinally relative to the second cutting element.   
     
     
         11 . The medical device assembly of  claim 1 , wherein the elongate member is radially offset from a central longitudinal axis of the self-expanding scaffold. 
     
     
         12 . A medical device assembly for incising a stenosis in a blood vessel, the medical device assembly comprising:
 an incising device including an expandable scaffold having a plurality of cutting elements projecting radially outward therefrom, and an elongate member extending proximally from the expandable scaffold to be manipulated by a user, the elongate member being radially offset from a central longitudinal axis of the expandable scaffold;   a tubular sheath having a lumen therethrough, the expandable scaffold positionable in the lumen of the tubular sheath in a contracted configuration with the plurality of cutting elements engaged with an interior of the tubular sheath; and   a catheter having a catheter shaft and an inflatable balloon mounted thereon, the inflatable balloon of the catheter configured to be advanced distally into an interior of the expandable scaffold through a proximal opening of the expandable scaffold with the catheter shaft positioned along an exterior surface of the elongate member;   wherein inflation of the inflatable balloon urges the cutting elements radially outward to incise a stenosis.   
     
     
         13 . The medical device assembly of  claim 12 , wherein the incising device is advanceable over a guidewire positioned along an exterior surface of the elongate member. 
     
     
         14 . The medical device assembly of  claim 13 , wherein the catheter is advanceable over the guidewire. 
     
     
         15 . The medical device assembly of  claim 13 , wherein the incising device includes a distal tip including a guidewire lumen for receiving the guidewire therethrough, the distal tip being arranged coaxially with the expandable scaffold. 
     
     
         16 . The medical device assembly of  claim 15 , wherein the catheter includes a distal tip configured to contact a proximal end of the distal tip of the incising element when the inflatable balloon is properly positioned within the interior of the expandable scaffold. 
     
     
         17 . The medical device assembly of  claim 12 , wherein the expandable scaffold includes a plurality of helically arranged wires converging at and secured to a distal tip of the incising device. 
     
     
         18 . A medical device assembly for incising a stenosis in a blood vessel, the medical device assembly comprising:
 an expandable scaffold configured to be expandable from a first contracted configuration to a second expanded configuration;   a cutting element secured to the expandable scaffold and extending radially outward therefrom; and   an elongate member extending proximally from the expandable scaffold;   wherein the elongate member is radially offset from a central longitudinal axis of the expandable scaffold.   
     
     
         19 . The medical device assembly of  claim 18 , wherein at least one end of the cutting element is slidable relative to the expandable scaffold as the expandable scaffold expands from the first contracted configuration to the second expanded configuration. 
     
     
         20 . The medical device assembly of  claim 18 :
 wherein the cutting element is a first cutting element;   wherein the medical device assembly further comprises a second cutting element; and   wherein the first cutting element is offset longitudinally relative to the second cutting element.