Intravascular arterial to venous anastomosis and tissue welding catheter

Abstract

A method of creating an arteriovenous (AV) fistula between first and second vessels includes inserting a catheter comprising a proximal member and a distal member into the first vessel so that the distal member comes into contact with a selected anastomosis site. Creating an aperture between the first and second vessels advancing the distal member into the second vessel. Clamping the first and second vessels together using the proximal and distal members. Applying energy to a heating member on one of the proximal and distal members to further cut the first and second vessels and shape the aperture. The step of applying energy to the heating member further cauterizes and welds an edge of the aperture in order to create the desired fistula between the first and second vessels.

What is claimed is: 
     
         1 . A method of creating an arteriovenous (AV) fistula between first and second vessels comprising:
 inserting a catheter comprising a proximal member and a distal member into the first vessel so that the distal member comes into contact with a selected anastomosis site;   creating an aperture between the first and second vessels;   advancing the distal member into the second vessel;   clamping the first and second vessels together using the proximal and distal members; and   applying energy to a heating member on one of the proximal and distal members to further cut the first and second vessels and shape the aperture, the step of applying energy to the heating member further cauterizing and welding an edge of the aperture in order to create the desired fistula between the first and second vessels.   
     
     
         2 . The method as set forth in  claim 1 , further comprising dispersing heat away from the heating member using a heat spreader. 
     
     
         3 . The method as set forth in  claim 2 , wherein the heat spreader comprises a conductive material disposed on one of the proximal and distal members. 
     
     
         4 . The method as set forth in  claim 3 , wherein the conductive material is disposed below the heating member. 
     
     
         5 . The method set forth in  claim 2 , further comprising creating a heat gradient across a face of one of the proximal and distal members to weld the first and second vessels together. 
     
     
         6 . The method as set forth in  claim 1 , wherein applying energy to the heating member elongates the aperture. 
     
     
         7 . The method as set forth in  claim 1 , wherein applying energy to the heating member causes the proximal member to move closer to the distal member. 
     
     
         8 . The method as set forth in  claim 1 , wherein applying energy to the heating member comprises applying RF energy. 
     
     
         9 . The method as set forth in  claim 1 , wherein advancing the distal member comprises moving the distal member distally relative to the proximal member so that the distal member is spaced a greater distance from the proximal member after the advancing step is performed than it is before the advancing step is performed. 
     
     
         10 . The method as set forth in  claim 9 , further comprising retracting the distal member toward the proximal member to clamp the first and second vessels together. 
     
     
         11 . The method as set forth in  claim 10 , wherein advancing the distal member is performed by advancing a tubular structure distally from an outer tube comprising the proximal member, and retracting the distal member is performed by withdrawing the tubular structure proximally into the outer tube. 
     
     
         12 . The method as set forth in  claim 10 , wherein the catheter comprises first and second heating members, the first heating member being disposed on the proximal member and the second heating member being disposed on the distal member, wherein the first and second heating members are prevented from coming into contact with each other when the distal member is fully retracted. 
     
     
         13 . The method as set forth in  claim 9 , wherein the catheter is rotated during the advancing step. 
     
     
         14 . The method as set forth in  claim 1 , further comprising applying tension to the heating member to seat the heating member against one of the first and second vessels. 
     
     
         15 . The method as set forth in  claim 1 , further comprising capturing tissue cut from the first and second vessels.