Objective: To assess the value of intraoperative graft flow and resistance measurements and a graft surveillance program to predict at-risk infra-inguinal bypass grafts.
Methods: Four hundred sixty-eight infra-inguinal bypass procedures performed between 1995-2006 underwent intraoperative measurement of graft flow and resistance using a Scimed OpDop. These data were correlated with graft outcome at six weeks. Two hundred fifty-four (73%) grafts were entered into a graft surveillance program and the effect of this on primary-assisted graft patency was assessed.
Results: Overall primary and primary-assisted graft patency was 81% and 83% at six weeks and 42% and 64% at three years. Grafts failing by six weeks had significantly lower flow (130.5 mL/min vs. 150.5 mL/min, P = .009) and higher resistance (0.67 peripheral resistance units (PRU) vs. 0.57 PRU, P = .004) than those remaining patent. However, OpDop measured flow and resistance was a poor predictor of graft failure in individual cases (area under ROC curve, 0.57). While there was no statistical difference in primary 18-month patency rates between grafts undergoing surveillance and those undergoing clinical follow up (55% vs. 76%, P = .133), primary-assisted 18-month patency rates were significantly higher in the surveillance group (83% vs. 77%, P = .042).
Conclusion: Intraoperative measurements of graft flow and resistance do not predict graft outcome at six weeks. However, surveillance does identify at-risk grafts and improves mid-term primary-assisted patency.