A catheter system for creating an arteriovenous (AV) fistula includes a proximal base having a distal end surface. A distal tip is connected to the proximal base and is movable relative to the proximal base. The distal tip has a proximal end surface. The distal end surface and the proximal end surface are adapted to contact opposing sides of a tissue portion to create the fistula. A peripheral edge defines the distal end surface of the proximal base. A stop is formed in the peripheral edge and is configured to limit movement of the distal tip in a proximal direction.