RESUMO
OBJECTIVE/BACKGROUND: To assess the outcomes of infrainguinal bypass performed for acute limb ischaemia, as well as the predictors of patency, mortality, and amputation. METHODS: This was a retrospective cohort study of patients undergoing infrainguinal bypass between 1998 and 2014. The cohort was stratified according to the indication for surgery into two groups: group A (acute limb ischaemia) and group B (chronic lower extremity ischaemia). Comparative analysis was performed on comorbidities, surgical technique, and outcomes, as well as prognostic factors in group A. RESULTS: In total, 702 bypasses were performed (group A, n = 107; group B, n = 595). Differences between groups were detected in age (65.9 vs. 70.9 years; p = .03), diabetes (16% vs. 49%; p < .01), renal insufficiency (6% vs. 13%; p = .05), stroke (7% vs. 14%; p = .04), and coronary artery disease (13% vs. 28%; p < .01). Patients with acute limb ischaemia more often required general anaesthesia (47% vs. 12%; p < .01) and a short bypass was more often performed (32% vs. 7%; p < .01). Median follow up was 23 and 24 months for groups A and B, respectively. No differences were found in patency rates at 1, 12, and 24 months between groups, but group B had a higher re-intervention rate during follow up. Primary patency in group A was 84%, 63%, and 58%, and in group B it was 88%, 62%, and 53% at 1, 12, and 24 months, respectively (p = .77). Assisted primary patency in group A was 85%, 72%, and 67%, and in group B it was 90%, 74%, and 66% at 1, 12, and 24 months, respectively (p = .61). Secondary patency in group A was 90%, 78%, and 75%, and in group B it was 94%, 80%, and 74% at 1, 12, and 24 months, respectively (p = .80). The freedom from re-intervention rate in group A was 91%, 74%, and 68%, and in group B it was 92%, 76%, and 71%, respectively (p = .04). Acute limb ischaemia was an independent risk factor for amputation (odds ratio [OR] 4.96, 95% confidence interval [CI] 1.74-14.09; p < .01) and mortality (OR 4.13, 95% CI 1.53-11.14; p = .01) at 30 days. In group A, female sex, prosthetic conduit, and need of distal thrombectomy were independently associated with worse patency rates. Poor intra-operative runoff was correlated with higher amputation rates. CONCLUSION: Among those undergoing infrainguinal bypass, patients who present with acute limb ischaemia constitute a subset showing higher early rates of amputation and death. In this subset of patients, worse outcomes may be expected for women, prosthetic conduits, need for distal thrombectomy, and patients with poor intra-operative runoff.