Focal ablation assembly

Abstract

A focal ablation assembly, used with an endoscope comprising an endoscopic tube, comprises a cryogenic catheter, a balloon and a reinforcing element. The cryogenic catheter is placeable within the endoscopic tube channel and has a distal end placeable at the distal end of the endoscopic tube. The balloon is mountable to the catheter distal end and extends distally of both of the distal ends. The reinforcing element at least partially defines the shape of the balloon in the expanded state. The balloon defines a balloon volume when expanded and has a thermally conductive therapeutic region which provides effectively no thermal insulation. In some examples the focal ablation assembly comprises a delivery catheter extending along the channel with a distal portion fluidly coupled to the balloon interior, whereby refrigerant can be introduced into the balloon interior and towards the therapeutic region by the delivery catheter.

What is claimed is:  
     
         1 . A focal ablation assembly, adapted for use with an endoscope within a hollow body structure, the hollow body structure having a target site at an inner surface thereof and a target site cross-sectional area at the target site, the endoscope comprising an endoscopic tube having proximal and distal ends and defining a channel extending between the proximal and distal ends, the focal ablation assembly comprising:
 a cryogenic catheter placeable within the channel, the cryogenic catheter defining a catheter lumen and having a distal end placeable at the distal end of the endoscopic tube;   a balloon mountable to the distal end of the cryogenic catheter, the balloon extending distally of both of the distal ends of the endoscopic tube and the cryogenic catheter;   the balloon placeable in collapsed and expanded states, the balloon having a balloon interior and a balloon sidewall, the sidewall having a thermally conductive therapeutic region providing effectively no thermal insulation;   a balloon-shape-affecting reinforcing element located within the balloon interior;   with the balloon in the expanded state at the target site, the reinforcing element comprising spaced apart elements (1) placing the balloon into a flattened configuration to better conform to the hollow body structure, and (2) helping to maintain the therapeutic region in direct contact with the hollow body structure; and   the cross-sectional area of the balloon when the balloon is in the flattened configuration at the target site being substantially greater than the target site cross-sectional area.   
     
     
         2 . The assembly according to  claim 1 , wherein the spaced apart elements comprise at least two spaced-apart support wires extending at least part way along the balloon interior. 
     
     
         3 . The assembly according to  claim 1 , wherein the balloon is made of an elastomeric material. 
     
     
         4 . The assembly according to  claim 1 , wherein the thermal conductivity of the balloon is greater at the therapeutic region than at least a portion of the remainder of the balloon. 
     
     
         5 . The assembly according to  claim 1 , wherein the endoscopic tube has a centerline and the therapeutic region is oriented oblique to the centerline when the cryogenic catheter is located within the endoscopic channel. 
     
     
         6 . The assembly according to  claim 1 , wherein the therapeutic region is generally elliptical. 
     
     
         7 . The assembly according to  claim 1 , wherein the therapeutic region has a cross-sectional area and the endoscopic tube has a cross-sectional area, the cross-sectional area of the therapeutic region being greater than the cross-sectional area of the endoscopic tube when the balloon is in the flattened configuration. 
     
     
         8 . The assembly according to  1 , further comprising a delivery catheter extendable along the channel and having a distal portion fluidly coupled to the balloon interior, whereby refrigerant can be introduced into the balloon interior and towards the therapeutic region by the delivery catheter. 
     
     
         9 . The assembly according to  claim 8 , wherein the refrigerant delivery catheter extends through the cryogenic catheter. 
     
     
         10 . The assembly according to  claim 8 , further comprising an exhaust lumen defined by the catheter lumen. 
     
     
         11 . The assembly according to  claim 8 , further comprising an exhaust lumen adapted for use within at least one of (1) the channel of the endoscopic tube, and (2) the catheter lumen. 
     
     
         12 . The assembly according to  claim 8 , wherein the distal portion of the delivery catheter has multiple exit openings for the discharge of the refrigerant into the balloon and towards the therapeutic region. 
     
     
         13 . A focal ablation assembly, adapted for use with an endoscope within a hollow body structure, the hollow body structure having a target site at an inner surface thereof and a target site cross-sectional area at the target site, the endoscope comprising an endoscopic tube having proximal and distal ends and defining a channel extending between the proximal and distal ends, the focal ablation assembly comprising:
 a cryogenic catheter placeable within the channel, the cryogenic catheter defining a catheter lumen and having a distal end placeable at the distal end of the endoscopic tube;   a balloon mountable to the distal end of the cryogenic catheter, the balloon extending distally of both of the distal ends of the endoscopic tube and the cryogenic catheter;   the balloon placeable in collapsed and expanded states, the balloon having a balloon interior and a balloon sidewall, the sidewall having a thermally conductive therapeutic region providing effectively no thermal insulation;   a balloon-shape-affecting reinforcing element located within the balloon interior;   with the balloon in the expanded state at the target site, the reinforcing element comprising:
 means for placing the balloon into a flattened configuration to better conform to the hollow body structure; and 
 means for helping to maintain the therapeutic region in direct contact with the hollow body structure; and 
   the cross-sectional area of the balloon when the balloon is in the flattened configuration at the target site being substantially greater than the target site cross-sectional area.