THROMBOLYSIS OF OCCLUDED INFRAINGUINAL BYPASS GRAFTS

From January 1993 to December 1995, intraarterial catheter guided urok inase infusion was used as an initial approach in the management of 29 episodes of infrainguinal graft thrombosis (12 venous and 17 prosthet ic grafts) in 27 patients. The infusion catheter was embedded inside t he occluding clot which was infiltrated by 225.000 U urokinase from di stal to proximal. Local low-dose urokinase (1.000 U/kg/hr) was continu ed for a mean of 39 hours. By this regimen, prompt relief of ischaemia was achieved in 69% (20/29) of cases. Complete recanalization was obt ained 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 ret hrombosis resulted in an amputation. The immediate limb-salvage rate w as 89% (26/29). Surgical intervention was avoided in 17 cases (58%). T he main hospital stay was 13 days. The short-term follow-up (mean of 1 7 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%. Thrombolyt ic management of infrainguinal occluded bypass grafts gives excellent initial technical results (79%), minimizing the need for major surgica l revision. It is however characterized by a high procedure-related mo rbidity (21%). These immediate favourable results are not longstanding . Diffuse graft disease, Limited outflow and high recurrence rate of a nastomotic stenoses after balloon angioplasty explain poor long-term r esults after thrombolysis of failed grafts.