Flow waveform analysis and long-term results of autogenous saphenous vein and polytetrafluoroethylene grafts in 140 arterial reconstructions of the lower limbs.

In previous work we have found that the outcome of grafts in the lower limbs correlated with the flow waveform pattern of the artery. We have retrospectively reviewed 140 femoro-popliteal bypass operations involving the use of 75 saphenous vein grafts and 65 polytetrafluoroethylene (PTFE) grafts. For grafts with type 0 or I flow waveform pattern the patency at 4 years (56%) was superior to grafts with the type II, III or IV flow waveform (35%) patterns (P less than 0.05). For saphenous vein grafts with type 0 or I flow, the patency rate was 78% at 3 years and 69% at 5 and 8 years. In contrast with type II, III or IV flow the patency rate was 52% at 3 years, 48% at 5 years and 34% at 8 years, with a statistical significance at 4 years (P less than 0.05). PTFE grafts with type 0 or I flow showed a tendency toward an increased patency which was not significant in comparison with the grafts with type II, III or IV flow (P = 0.12). Saphenous vein grafts with type II flow patterns had an increased occlusive rate in the first year whereas PTFE grafts had the same tendency within 2 years. In both types of graft, early occlusions within a month of operation were encountered in grafts with a type III or IV flow waveform pattern. These results indicate that the fate of the reconstructed arteries of the lower limb could be predicted by flow waveform analysis, and a careful and serial postoperative evaluation of the graft should be made, particularly those with type II, III or IV flow waveform patterns.