Side branch balloon

Abstract

An improved balloon catheter structure includes a beveled distal tip, a reinforced distal portion, and an elastic or split sleeve over at least a portion of the balloon. The balloon may have a short length and a marker at its midline. The catheters are particularly useful for crossing through stent walls at vessel bifurcations.

What is claimed is: 
     
         1 . A balloon catheter having improved crossing characteristics, said catheter comprising
 a catheter body having a distal end, a proximal end, and an inflatable balloon near the distal end,   wherein a distal tip is asymmetrically beveled relative to a longitudinal axis of the catheter body, and   wherein the catheter body comprises a braided shaft section to torsionally reinforce the distal portion thereof, thereby improving rotation of the beveled distal tip when the catheter body is placed in vasculature.   
     
     
         2 . A balloon catheter as in  claim 1 , wherein at least a portion of the balloon is covered with an expandable sleeve. 
     
     
         3 . A balloon catheter as in  claim 2 , wherein the expandable sleeve covers at least a distal region of the balloon to enhance column strength of a distal region of the catheter shaft and to present a smooth forward-facing surface as the catheter is advanced through the vasculature. 
     
     
         4 . A balloon catheter as in  claim 2 , wherein the expandable sleeve covers at least a proximal portion of the balloon to enhance the column strength of a proximal region of the catheter body and to present a smooth proximal-facing surface as the catheter is withdrawn through the vasculature. 
     
     
         5 . A balloon catheter as in  claim 2 , wherein the sleeve is elastic to expand and contract over the balloon as the balloon is inflated and deflated. 
     
     
         6 . A balloon catheter as in  claim 2 , wherein the sleeve splits as the balloon is inflated. 
     
     
         7 . A balloon catheter as in  claim 1 , wherein the balloon has a length when inflated in the range from 3 mm to 6 mm and a radiopaque marker at its middle. 
     
     
         8 . A balloon catheter as in  claim 7 , wherein the balloon is non-distensible and has a diameter in the range from 1 mm to 5 mm when fully inflated. 
     
     
         9 . A balloon catheter as in  claim 1 , wherein the braided shaft section is attached to a proximal shaft section comprising a hypotube. 
     
     
         10 . A balloon catheter as in  claim 1 , wherein the braided shaft section is attached to a proximal shaft section comprising a polymeric balloon catheter shaft.