Balloon catheter devices with sheath covering

Abstract

Catheter devices having an expandable balloon for delivering a therapeutic agent to a body site. In one aspect, one or more sheaths are disposed around the balloon with the therapeutic agent being disposed within the sheath, being disposed over the sheath, being contained in the space between the sheath and the balloon, or being otherwise associated with the sheath. In another aspect, the balloon includes a micro-electromechanical system (MEMS) for drug delivery.

We claim: 
     
         1 . A medical device comprising:
 a catheter;   a balloon mounted on the catheter;   a sheath disposed around the balloon, wherein the sheath comprises a body and a plurality of reservoirs that are in communication with the external surface of the body of the sheath, wherein the reservoirs are elongated channels within the body of the sheath; and   a therapeutic agent contained in the reservoirs.   
     
     
         2 . The medical device of  claim 1 , wherein expansion of the balloon applies pressure to the reservoirs and causes the release of the therapeutic agent. 
     
     
         3 . The medical device of  claim 1 , wherein the sheath has a non-linear compliance curve. 
     
     
         4 . The medical device of  claim 1 , wherein the sheath comprises an elastomeric mesh. 
     
     
         5 . The medical device of  claim 1 , wherein the channels are longitudinally-extending. 
     
     
         6 . The medical device of  claim 1 , wherein the reservoirs communicate with the external surface of the body of the sheath via a plurality of pores. 
     
     
         7 . The medical device of  claim 1 , wherein the sheath comprises a material having a porous cell structure. 
     
     
         8 . The medical device of  claim 7 , wherein the material is ePTFE. 
     
     
         9 . The medical device of  claim 1 , wherein the therapeutic agent is an anti-proliferative agent or an anti-restenosis agent. 
     
     
         10 . The medical device of  claim 9 , wherein the therapeutic agent is paclitaxel, sirolimus, tacrolimus, everolimus, or zotarolimus.