Protective sheath assembly for a polymer scaffold

Abstract

A medical device includes a polymer scaffold crimped to a catheter having an expansion balloon. A sheath is placed over the crimped scaffold after crimping to reduce recoil of the crimped polymer scaffold and maintain scaffold-balloon engagement relied on to hold the scaffold to the balloon when the scaffold is being delivered to a target in a body. The sheath is removed by a health professional either by removing the sheath directly or using a tube containing the catheter.

1 - 15 . (canceled) 
     
     
         16 . A method, comprising:
 providing a tube having a lumen, and contained within the lumen a catheter including a scaffold crimped to a balloon, wherein a sheath constrains the scaffold; and   removing the sheath from the catheter by removing the catheter from the tube.   
     
     
         17 . The method of  claim 16 , wherein the tube extends from at least a catheter distal end comprising the balloon to a catheter proximal end comprising a hub. 
     
     
         18 . The method of  claim 16 , wherein the scaffold and catheter are configured for implantation within a body only after the catheter is removed from the tube and the sheath is removed from the scaffold. 
     
     
         19 . The method of  claim 16 , wherein the tube is rigid compared to the sheath. 
     
     
         20 . The method of  claim 16 , wherein the removing the sheath step includes engaging a first member of the tube with a second member of the catheter, and the first member moves the second member towards the catheter distal end when the catheter is removed from the tube. 
     
     
         21 . A method, comprising:
 using a catheter having a hub located at a proximal end thereof and, at a distal end thereof,   a scaffold crimped to a balloon and a sheath covers the scaffold, wherein the sheath includes a portion having an outer diameter (d 1 );
 using a tube having a lumen, the lumen forming
 an inner diameter defining a second clearance (d 2 ) that is greater than d 1 , and 
 a member defining a third clearance (d 3 ) that is less than d 1 ; 
 
 wherein a substantial portion of the catheter including the distal end is contained within the lumen; and 
 removing the catheter from the tube, comprising:
 engaging the sheath portion with the member and then moving the member towards the catheter distal end, whereupon the sheath is removed from the scaffold. 
 
   
     
     
         22 . The method of  claim 21 , wherein the tube distal end is separable from the tube proximal end and the proximal end comprises the member. 
     
     
         23 . The method of  claim 21 , wherein the scaffold and catheter are configured for implantation within a body only after the catheter is removed from the tube and the sheath is removed from the scaffold. 
     
     
         24 . The method of  claim 21 , wherein a substantial portion of the tube lumen forms the second clearance. 
     
     
         25 . The method of  claim 21 , wherein the third clearance of the tube is between the balloon and the hub. 
     
     
         26 . The method of  claim 21 , wherein the third clearance of the tube is adjacent the hub. 
     
     
         27 . A method, comprising:
 using a catheter having a proximal end comprising a hub and a distal end comprising a balloon, wherein a catheter portion extending from the proximal end to the distal end is contained within a first tube;   placing the catheter distal end into a second tube; and   connecting the first tube to the second tube;   wherein a scaffold is crimped to the balloon and a sheath covers the scaffold; and   wherein the first tube comprises a neck at a proximal end adjacent the catheter hub, the neck being configured to remove a sheath from the scaffold when the catheter distal end is pulled through the neck.   
     
     
         28 . The method of  claim 27 , further comprising crimping the scaffold to the balloon while the catheter portion is within the first tube lumen and before the catheter distal end is placed within the second tube. 
     
     
         29 . The method of  claim 27 , wherein the scaffold and catheter are configured for implantation within a body only after the catheter is removed from the tube and the sheath is removed from the scaffold.