Colour duplex scanning and pulse-generated run-off for assessment of popliteal and cruropedal arteries before peripheral bypass surgery

BACKGROUND: This prospective pilot study compared the diagnostic accuracy of duplex scanning and pulse-generated run-off (PGR) with intra-arterial digital subtraction angiography (IADSA) for assessment of popliteal, crural and pedal arteries, and explored the reliability of investigation with the combination of duplex scanning and PGR in patients who needed femorodistal reconstruction. METHODS: In 23 limbs, 345 arterial segments were graded independently with duplex scanning and IADSA as normal, stenosed or occluded and compared using weighted kappa analysis. PGR was rated as good, poor or no run-off and compared with pedal arch patency on IADSA. Based on information derived from duplex scanning and PGR a vascular surgeon proposed treatment and the distal anastomosis site for bypass, which was compared with definitive treatment as determined by IADSA. RESULTS: Overall agreement between duplex scanning and IADSA for popliteal and crural arteries was moderate (kappa 0.47, 95 per cent confidence interval (c.i.) 0.39-0.55) with best agreement within the popliteal and proximal tibial arteries. Agreement within pedal arteries was fair (kappa 0.35, 95 per cent c.i. 0.17-0.53). PGR detected good run-off in five of 21 pedal arteries shown to be occluded on IADSA. In 16 of 23 patients treatment based on duplex scanning and PGR was identical to that based on IADSA. Eight of eleven femoropopliteal bypasses were predicted accurately. CONCLUSION: Operative strategy could have been based on investigation by duplex scanning and PGR in a substantial number of patients scheduled for femoropopliteal bypass surgery. Agreement between duplex scanning and IADSA within very distal arterial segments was fair