Intra-operative haemodynamic findings and their prognostic significance in femoropopliteal reversed saphenous vein graft bypass operations.

Post-reconstructive graft blood flow (basal flow') was measured by means of an electromagnetic flowmeter in 72 consecutive femoropopliteal reversed saphenous vein grafts performed for occlusive atherosclerosis causing leg ischaemia. In the last 48 operations, post-reconstructive pre- and post-graft intra-arterial pressures were recorded, and graft blood flow after papavarine-induced vasodilation ('maximal flow') was measured. Mean 'basal flow' was 132 ml/min, mean 'maximal flow' 285 ml/min and mean flow increment after papavarin 136%. Mean 'basal flow', mean 'maximal flow' and mean flow increment after papavarine were higher in the claudication group than in the gangrene group, and higher in cases having good angiographic run-off than in those having poor. Mean common femoral and popliteal pressures were 85 and 80 mmHg, with no differences between different groups. Mean post-reconstructive graft pressure gradient was 5.1 mm. Mean peripheral resistance was 769 milliprus, being higher in the gangrene group and in cases having poor run-off. The prognostic significance of these findings was evaluated by analysing patency in all patients living 3 months ('early') and 1 year ('late') after operation. Cases having a 'basal flow' less than 60 ml/min, a 'maximal flow' less than 200 ml/min or a flow increment after papavarine less than 100% had significantly poorer 'early' patency (p less than 0.01) and 'late' patency (p less than 0.05). Femoral and popliteal pressures, graft pressure gradients and peripheral resistance did not influence patency significantly.