Figure 15From: Coronary artery bypass grafting hemodynamics and anastomosis design: a biomedical engineering reviewTyrell vein collar. Diagram of a Tyrell vein collar (a) without and (b) with a PTFE graft. Trials of Tyrrell collar venous anastomosis in AVGs have not shown any improvement in graft patency (taken from [154] with permission).Back to article page