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 short-term efficacy and safety of prolonged, low dose, direct urokinase infusion in recanalization of chronically occluded saphenous vein bypass grafts in a large sample of patients, as well as to determine the 6-month patency rates for this procedure.

BACKGROUND

Patients with chronically occluded 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 coaxial infusion of urokinase (100,000 U/h) was given directly into occluded vein grafts in 107 patients. Balloon angioplasty was performed after lysis was achieved. Patients were discharged with warfarin and aspirin therapy. Six-month clinical follow-up data were obtained, and repeat 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 acute myocardial infarction in 5 patients (5%), enzyme level elevation in 18 (17%), emergency coronary artery bypass graft surgery in 4 (4%), stroke in 3 (3%) and death in 7 (6.5%). Recanalization was unsuccessful in all seven patients who died. Six-month follow-up angiograms were obtained for 40 patients (54%), 16 of whom maintained a patent graft (40%). Angina was present in 13 patients with successful (22%) and 12 with unsuccessful (71%) recanalization at 6-month follow-up.

CONCLUSIONS

Chronically occluded aortocoronary vein grafts can be recanalized in approximately 70% of appropriately selected patients. Complications are similar to those observed with repeat operations. Clinical follow-up shows an improvement in angina. This procedure is intended for patients with only one occluded vein graft. Strict adherence to the protocol will improve patency and reduce complications.