This observational study retrospectively analyzed 159 consecutive patients (114 men), median age, 65 years (range 57–73 years), with 89 native artery (56%), and 70 prosthetic bypass graft (44%) occlusions of the lower extremity. All patients were treated with catheter-directed thrombolysis between 2006 and 2009 in 2 vascular referral centers in the Netherlands. The severity of ischemia was Rutherford class I (52%), class IIa (27%), class IIb (12%) and unknown (9%) in native arteries and class I (64%), class IIa (19%), class IIb (1%), and unknown (16%) in bypass grafts. Median (range) duration of symptoms before the start of thrombolysis was 3.5 (1–14) days in native arteries and 3 (1–9) days in bypass grafts. All patients were treated with a continuous dosage of urokinase (100,000 IU/h). Amputation-free survival was estimated by conduit type using the Kaplan–Meier method and compared using the log-rank test. Univariate and multivariate analyses were performed using a Cox proportional hazards model.
Complete (>95%) lysis was achieved in 69% of native arteries and bypass grafts (P = 1.00). Major hemorrhagic complications occurred in 12% (4% hemorrhagic strokes, of which 2% were fatal) of native arteries and in 7% (0% hemorrhagic stroke) of bypass grafts (P = 0.28). The 30-day mortality rate was 6% in native arteries and 1% in bypass grafts (P = 0.17), and the 30-day amputation rate was 10% in native arteries and 13% in bypass grafts (P = 0.45). Mean follow-up was 27 ± 19 months. Amputation-free survival at 1 year was 76% for native arteries and 78% for bypass grafts and at 5 years was 65% for native arteries and 51% for bypass grafts (P = 0.32). Multivariate analysis showed 2 negative predictors for amputation-free survival: age >65 years and cerebrovascular disease. Conduit type was not an independent predictor for amputation-free survival (P = 0.78).
Despite initial promising results, long-term follow-up of catheter-directed thrombolysis for acute lower extremity occlusions showed a disappointing amputation-free survival. In multivariate analysis, no significant differences in amputation-free survival between native arteries and prosthetic bypass grafts were determined.