RECANALIZATION OF CHRONICALLY OCCLUDED AORTOCORONARY SAPHENOUS-VEIN BYPASS GRAFTS WITH LONG-TERM, LOW-DOSE DIRECT INFUSION OF UROKINASE (ROBUST) - A SERIAL TRIAL

Objectives. This multicenter study sought to evaluate the shortterm ef ficacy and safety of prolonged, low dose, direct urokinase infusion in recanalization of chronically occluded saphenous vein bypass grafts i n a large sample of patients, as well as to determine the 6-month pate ncy rates for this procedure. Background. Patients with chronically oc cluded aortocoronary vein grafts and uncontrolled angina pectoris have limited options for therapy. Previous work has shown that chronically occluded vein grafts can be recanalized by thrombolysis. Methods. A c oaxial infusion of urokinase (100,000 U/h) was given directly into occ luded vein grafts in 107 patients. Balloon angioplasty was performed a fter lysis was achieved. Patients were discharged with warfarin and as pirin therapy. Six-month clinical follow up data were obtained, and re peat angiography was encouraged. Results. Initial patency was achieved in 74 patients (69%). Mean duration of infusion was 25.4 h, and mean urokinase dosage was 3.70 million U. Acute adverse events included acu te myocardial infarction in 5 patients (5%), enzyme level elevation in 18 (17%), emergency coronary artery bypass graft surgery in 4 (4%), s troke in 3 (3%) and death in 7 (6.5%). Recanalization was unsuccessful in all seven patients who died. Six-month follow-up angiograms were o btained for 40 patients (54%), 16 of whom maintained a patent graft (4 0%). Angina was present in 13 patients with successful (22%) and 12 wi th unsuccessful (71%) recanalization at 6-month follow-up. Conclusions . Chronically occluded aortocoronary vein grafts can be recanalized in similar to 70% of appropriately selected patients. Complications are similar to those observed with repeat operations. Clinical follow-up s hows an improvement in angina. This procedure is intended for patients with only one occluded vein graft. Strict adherence to the protocol w ill improve patency and reduce complications.