Thrombolysis of occluded infrainguinal bypass grafts

From January 1993 to December 1995, intraarterial catheter guided urokinase infusion was used as an initial approach in the management of 29 episodes of infrainguinal graft thrombosis (12 venous and 17 prosthetic grafts) in 27 patients. The infusion catheter was embedded inside the occluding clot which was infiltrated by 225.000 U urokinase from distal to proximal. Local low-dose urokinase (1.000 U/kg/hr) was continued for a mean of 39 hours. By this regimen, prompt relief of ischaemia was achieved in 69% (20/29) of cases. Complete recanalization was obtained in 79% of cases. In six cases, the graft remained totally (n = 3) or partially (n = 3) occluded. Two of these patients benefited from secondary surgery, two improved clinically by conservative treatment, and two required amputation. In the 23 successful cases, thrombolysis unmasked an underlying flow-limiting stenosis in 83% (19/23), that was subsequently corrected by percutaneous balloon angioplasty (n = 15), by surgery (n = 3), or by a combination of both (n = 4). One early rethrombosis resulted in an amputation. The immediate limb-salvage rate was 89% (26/29). Surgical intervention was avoided in 17 cases (58%). The main hospital stay was 13 days. The short-term follow-up (mean of 17 months) reveals a high early rethrombosis rate (8/23 or 35%) within one year. Four of these repeated graft failures evolved to amputation. At one year, the overall limb salvage rate dropped to 79%. Thrombolytic management of infrainguinal occluded bypass grafts gives excellent initial technical results (79%), minimizing the need for major surgical revision. It is however characterized by a high procedure-related morbidity (21%). These immediate favourable results are not longstanding. Diffuse graft disease, limited outflow and high recurrence rate of anastomotic stenoses after balloon angioplasty explain poor long-term results after thrombolysis of failed grafts.