Impact of Bypass Flow Assessment on Long‐Term Outcomes in Patients with Chronic Limb‐Threatening Ischemia

Abstract

Transit time flow meter (TTFM) allows quick and accurate intraoperative graft assessment. The main study goal is to evaluate the influence of graft flow measurements on long-term clinical outcomes in patients with chronic limb-threatening ischemia (CLTI) undergoing bellow the knee (BTK) vein bypass surgery. Between January 1st, 1999 and January 1st, 2006, 976 CLTI consecutive patients underwent lower extremity bypass surgery. When applying the exclusion criteria, 249 patients were included in the final analysis. Control measurements were performed at the end of the procedure. Patients were divided according to the mean (more/less than 100ml/min) and diastolic graft flow (more/less than 40ml/min) values in four groups. The primary endpoints were a major adverse limb event (male) and primary graft patency. After the median follow-up of 68months, a group with the mean graft flow below 100ml/min and the diastolic graft flow below 40ml/min had the highest rates of male (χ2 = 36.60, DF = 1, P < 0.01, log-rank test) and the worst primary graft patency (χ2 = 53.05, DF = 1, P < 0.01, log-rank test). In patients with CLTI undergoing BTK vein bypass surgery, TTFM parameters, especially combined impact of mean graft flow less than 100ml/min and diastolic graft flow less than 40ml/min, were associated with an increased risk of poor long-term male and primary graft patency.