Thrombolysis for lower extremity bypass graft occlusion

Abstract

Background: Thrombolysis is a common method in the treatment of lower extremity bypass graft occlusion. The purpose of this study was to investigate the results of thrombolytic therapy in the management of acute bypass graft occlusion and to identify risk factors for technical failure and amputation.

Methods: All patients at two tertiary referral centers undergoing thrombolysis for acute graft occlusion in the lower limb between January 1, 2000 and December 31, 2008 were retrospectively reviewed. Factors associated with technical failure of thrombolytic therapy, major amputation, and mortality were determined with multivariate analysis, and long-term outcomes were assessed with the Kaplan-Meier method and log-rank test.

Results: During the study period, 123 patients underwent thrombolysis for acute bypass graft occlusion. Mean age was 69 years (range, 27-91 years); 38% were women. Sixty-seven percent had synthetic grafts. Acute critical leg ischemia (74%) was the dominating symptom preceding thrombolytic treatment. In 29% of cases, no adjunctive interventions were required, whereas 21% underwent open surgery, 39% endovascular intervention, and 11% underwent a hybrid procedure. Technical failure of thrombolysis occurred in 18 patients. Presence of ischemic heart disease (P = .013), older grafts (P = .014), and synthetic grafts (trend; P = .092) were associated with success of thrombolysis, and ischemic heart disease remained as an independent factor in the multivariate analysis for technical success of thrombolysis (P = .04; odds ratio 4.0; 95% confidence interval [CI; 1.1-15.1]), whereas there was a trend for older grafts (P = .089). Mean follow-up was 38 months (range, 0-119 months). The major amputation rate was 11% (14/123) at 1 month and 25% (31/122) at 1 year. In a Cox regression model, technical failure (P = .031; hazard ratio [HR] 2.58, 95% CI [1.0-6.08]), higher age (P = .004; HR 1.06, 95% CI [1.02-1.10]), and synthetic graft as opposed to vein graft (P = .050; HR 2.63, 95% CI [1.0-6.9]) remained as independent factors associated with major amputation. The amputation-free survival rate was 89% and 75% at 1 and 12 months, respectively. Higher age (P < .001; HR 1.06, 95% CI [1.03-1.09]) and acute limb ischemia (P = .007; HR 2.40, 95% CI [1.26-4.56]) remained as independent adverse factors associated with amputation-free survival.

Conclusions: Our findings support the use of thrombolysis in the treatment of acute bypass graft occlusion in the lower limb given its acceptable short- and long-term amputation-free survival rates. Technical failure and higher age were factors associated with major amputation. Synthetic grafts appeared to have a somewhat increased likelihood of technically successful thrombolysis compared with vein grafts, but on the other hand, they exhibited an increased risk of amputation during follow-up.