Intra-arterial urokinase as the initial therapy for acutely ischemic lower limbs Acute ischemia of the lower limb remains a significant risk to both life and limb. Mortality rates of approximately 10-30% and amputation rates of the same magnitude in the survivors are repeatedly reported despite advances in medical and surgical techniques. Our experience, which utilized percutaneous intra-arterial thrombolysis as the initial treatment in 72 instances (63 patients), has resulted in a markedly lower mortality rate of 1.6% and a lower amputation rate of 8.5% in the survivors. Careful categorization by clinical degree of ischemia indicates that 82% of the cases were either threatened or irreversible limb ischemia. The initial treatment with thrombolysis did not preclude subsequent prompt surgical treatment when necessary; in these cases, thrombolysis promoted improved surgical results (100%) when it was successful. It markedly reduced the need for urgent surgery, usually simplified the subsequent surgical approach, diminished the overall need for surgery, and often accomplished a successful outcome alone (31%). Significant bleeding was not noted during subsequent surgical procedures and was noted in only 2.8% of the cases. Confirmation of these results and further improvements in technique might justify the use of an initially high-dose urokinase transcatheter infusion regimen as the initial treatment of choice for acute lower-limb ischemia. 