Which distal anastomosis should be used in PTFE femoro-tibial bypass?

AIM: The PTFE prosthesis represents an alternative to the autologous saphenous vein in femoro-tibial revascularization for limb salvage in the absence of venous material in the patient. The aim of our study is to confirm the validity of PTFE revascularization and determine the best distal anastomosis in terms of patency using 3 different techniques. We carried out a retrospective analysis, evaluating patients who underwent PTFE femoro-tibial revascularization for critical ischemia.

METHODS: Between January 1998 and June 2002 we performed 46 femoro-tibial revascularizations at the Vascular Surgery Division of the Poliambulanza Hospital in Brescia using a PTFE prosthesis, from a total of 192 infrainguinal revascularizations (24%). All patients presented a critical ischemia, with trophic lesions or gangrene in 76% of the cases (35/46) and who were previously treated unsuccessfully with medical therapy. Seventeen cases (36%) were a redo bypass due to previously failed revascularization. In all cases the saphenous vein was not available due to past peripheral or coronary revascularization (45%), saphenectomy (20%) or inadequate diameter (35%). The distal anastomoses were performed on the peroneal artery in 29 cases, on the anterior tibial artery in 14 cases and on the posterior tibial artery in 3 cases. The distal anastomosis was performed by interposing a segment of vein between the prosthesis and the tibial artery in 12 cases; in 22 cases the interposition was performed using a vein patch, and in the remaining 12 cases a PTFE prosthesis provided with a premanufactured expanded anastomosis (Distaflo(c)) was used.

RESULTS: Average follow-up was 22.5 months (range: 3-48 months). The primary and secondary patency rate at 48 months, calculated with the Life table method, was 35% and 47%, respectively. Limb salvage in the same time period was 56%. Depending on the anastomosis performed (Distaflo(c), vein patch, distal vein) we obtained a secondary patency rate of 31%, 62%, and 44% respectively after 48 months with a significant difference between distal vein patch and the other two anastomoses (p<0.001).

CONCLUSIONS: The PTFE bypass on the tibial artery performed for limb salvage in the absence of a saphenous vein represents a valid alternative to other types of prostheses with a patency percentage that is acceptable in the medium term. Within our study population, anastomosis by vein patch interposition gave better results than other types of tibial anastomosis.