Revascularization of the limbs with urokinase and TEC catheter endarterectomy for occluded bypass grafts

Abstract

Occlusion of a femoral-popliteal or a femoral-tibial bypass graft on a prior occluded superficial femoral artery or the popliteal artery (in cases of ischemia of the legs) creates a complicated problem that may result in limb loss. The revascularization of such limbs with a repeat femoral-tibial or peroneal bypass is difficult and results in a high rate of limb loss from failure of the repeat grafts. Therefore, attempts were made to re-open the grafts through urokinase administration and thrombolysis for the grafts. To address the distal critical stenosis, or occlusion, the urokinase administration and thrombolysis were followed by endovascular endarterectomy using a thromboembolytic catheter (TEC). From 1990 to 1992, the above protocol was followed with 15 patients. In all patients, the protocol included 24 to 48 hours of urokinase administration with 60,000 to 120,000 U of urokinase per hour. A distal pathology was detected in all 15 patients, of whom 8 had complete occlusion at the site of distal anastomosis, 7 had critical stenosis ranging from 90% to 99%, and 1 was found to have a proximal critical stenosis at the femoral-graft junction. TEC catheter endarterectomy was performed to address the problem of occlusion and critically stenosed distal anastomotic lesions; a 100% success rate was immediately achieved, with flow being re-established to the distal limb. Fourteen of 15 patients remained well revascularized for more than 1 year. One patient experienced re-occlusion after 8 months; the occlusion was re-opened using the same technique of urokinase administration and the use of the TEC catheter, in which case the graft subsequently remained open. The longest follow-up of one patient is more than 2 years, during which time the graft has stayed open. With the aforementioned results, after revascularization of the ischemic limbs from occluded bypass grafts, it is strongly recommended that urokinase administration, along with TEC endovascular endarterectomy, be used to establish the circulation when occluded grafts threaten limb loss.