Clinical and angiographic selection factors for thrombolysis as initial therapy for acute lower limb ischemia.

The purpose of this study was to determine whether angiographic patterns correlate with the clinical severity of acute lower limb ischemia (ALLI) and with the outcome of treatment with percutaneous intraarterial thrombolysis (PIAT). A retrospective analysis was conducted of angiograms and case records of 186 consecutive PIAT infusions in 160 patients with ALLI. The number of segments of occlusions; associated stenoses of inflow, outflow, and collateral vessels; and the demonstration of patent distal vessels were correlated with severity of ischemia and outcome of PIAT. Occlusions requiring flow to traverse one collateral bed to supply patent distal vessels (angiographic category I) correlated with the "viable" clinical classification of ALLI. Those requiring blood to flow through two contiguous collateral beds to supply patent distal vessels (category II) correlated with the "threatened" clinical classification. Occlusions with distal propagation that occluded the distal vascular bed (category III) correlated with the "irreversible" clinical category. Rates at 30 days for patency, amputation, and mortality were as follows for category I: 100%, 0%, and 0%; category II: 90%, 8.6%, and 0.7%; and category III: 55%, 19%, and 5%, respectively. Angiographic patterns correlate well with clinical severity of ischemia and predict the outcome from PIAT as initial therapy of ALLI. Amputation and mortality rates are less than those reported for emergency surgical treatment of ALLI.