Mechanics of end-to-end artery-to-PTFE graft anastomoses

On some occasions vascular surgeons are called upon to construct an end-to-end anastomosis using prosthetic graft material. If a spatulated anastomosis is not fashioned, three important variables that are under the surgeon's control could affect anastomotic dimensions: (1) selection of graft material, (2) graft size relative to the native vessel, and (3) suture technique. Accordingly, studies were performed on 36 nonspatulated, end-to-end artery-to-polytetrafluoroethylene (PTFE) grafts to evaluate the effects of graft size and suture technique on anastomotic dimensions. Size-matched (3 mm) and slightly oversized (4 mm) grafts were anastomosed end-to-end to 3 mm pig carotid arteries using (1) running polypropylene (Surgilene) sutures, (2) running polybutester (Novafil) sutures, or (3) interrupted sutures. After 30 min the vessels were excised, filled with contrast material, and radiographs were obtained to measure anastomotic dimensions. Results showed that, at every comparable pressure, 4 mm grafts produced larger anastomoses than did 3 mm grafts. In addition 4 mm grafts produced smoother anastomoses without a constricted or "pinched" appearance at the graft-artery junction. Marked compliance mismatch was observed with both sized grafts. There was no significant difference in the dimensions of the anastomoses or compliance mismatch with the three different suture techniques. These studies indicate that, when using PTFE grafts for end-to-end anastomoses, a graft that is slightly larger than the artery is preferable to provide the largest and smoothest anastomosis, and that any of the three suture techniques may be used.