Anastomosis wire ring device

An anastomotic ring device (12,212,312,412,512,712,812) for forming a hollow rivet (ring) attachment between tissue lumens facilitates laparoscopic or endoscopic implantation by including features that facilitate actuation from a stressed, generally cylindrical shape. Economical manufacturer is achieved by weaving open ended strands into a generally cylindrical stent shape that is imparted with a Shape Memory Effect (SME) to actuate to a hollow rivet (ring) shape. Alternatively or in addition to SME inherent in the woven strands, an actuating force may be received from a helical spring element (530) incorporated into the ring. Self-actuating ring devices are enhanced by forming woven strands into petals that diverge from opposing petals such that the strands encounter less friction when actuating. Each of these features alone or in combination enhance clinical use of anastomotic ring devices, such as a bariatric gastric bypass procedure.