Patent ID: 8034064

Claim:
A method for forming an anastomosis opening in a side of a blood vessel to facilitate fluid communication with a tubular structure, the method comprising: positioning an anvil in a lumen of a blood vessel at an anastomosis site, wherein the anastomosis site is located in the side of the blood vessel, wherein the anvil comprises a receiving surface at one end and a side surface; moving the anvil at least partially into an opening of a ring so that a portion of a wall of the blood vessel at the anastomosis site is held between the side surface of the anvil and the ring and such that the receiving surface of the anvil causes a region of the wall to extend beyond the portion of the wall held between the side surface of the anvil and the ring in conformance with the shape of the anvil, wherein a component of the anvil extends through a piercing located in the extended region of the wall of the blood vessel; and forming an anastomosis opening in the wall of the blood vessel at the anastomosis site while extending the region of the wall of the blood vessel beyond the portion that is held between the side surface of the anvil and the ring such that at least part of the region of the wall of the blood vessel that was extended rests on the side surface of the anvil after formation of the anastomosis opening, wherein the anastomosis opening is larger than the piercing, wherein the anastomosis opening is formed without requiring interruption of blood flow through the blood vessel at the anastomosis site, leaving the ring at the anastomosis site after forming the anastomosis opening and after removing the anvil.