Systems and methods for percutaneous access and formation of arteriovenous fistulas

A catheter system for creating an arteriovenous (AV) fistula, comprising:

• a proximal base having a distal diagonal end surface;
• a distal tip connected to the proximal base and movable relative to the proximal base, the distal tip having a proximal diagonal end surface, the distal diagonal end surface and the proximal diagonal end surface being adapted to contact opposing sides of a tissue portion to create the fistula;
• a peripheral edge defining said proximal diagonal end surface;
• a proximal point on said peripheral edge;
• and
• a relief recess disposed along a side wall defining a length of the proximal base, wherein the relief recess has a depth extending radially inwardly from an outer surface of the side wall toward a straight operating axis along which an entire length of the proximal base is disposed, the relief recess having an axial length which is greater than the depth of the recess.