TREATMENT OF THROMBOTIC SAPHENOUS-VEIN BYPASS GRAFTS USING LOCAL UROKINASE INFUSION THERAPY WITH THE DISPATCH CATHETER

Percutaneous treatment of thrombotic stenoses or total occlusions in a ged saphenous vein bypass grafts is associated with a significant inci dence of complications primarily related to distal embolization. The p urpose of this study was to assess the efficacy of local urokinase del ivery with the Dispatch catheter prior to balloon angioplasty and/or i ntragraft stent placement as a new technique of vein graft revasculari zation. Local urokinase delivery with the Dispatch catheter was perfor med in 15 saphenous vein grafts (mean age = 11.7 +/- 2.5 yr) in 13 pat ients with unstable or postinfarction angina. The target lesion was a total occlusion in 5 of the procedures and a severe vein graft stenosi s in the remaining 10, In all cases, urokinase was administered direct ly to the site of the stenosis/occlusion via the Dispatch catheter at 0.5 cc/min and at a concentration of 30,000 units/cc. The mean urokina se infusion time for the 15 procedures was 33 +/- 10 min (range = 10-6 0 min) and the mean urokinase dose was 495,000 +/- 158,000 units (rang e = 150,000-900,000 units). Following Dispatch therapy, mean minimal l umen diameter increased from 0.34 +/- 0.32 to 1.81 +/- 0.78 mm (P < 0. 01), mean TIMI flow increased from 1.9 +/- 1.4 to 2.8 +/- 0.8 (P < 0.0 6), and mean thrombus score was reduced from 2.3 +/- 0.6 to 0.3 +/- 0. 8 (P < 0.01). Mild no reflow was noted in two cases, although no patie nt demonstrated angiographic evidence of gross distal embolization, On e of the patients with no reflow also demonstrated a small increase in cardiac enzymes, Subsequent balloon angioplasty/stent placement was s uccessful in 14 of the 15 procedures (93% success rate), This prelimin ary report suggests that pretreatment of thrombotic saphenous vein gra ft stenoses with local urokinase delivery via the Dispatch catheter ma y decrease intragraft thrombus and possibly decrease the incidence of vascular complications associated with percutaneous intervention. This technique may allow for recanalization of totally occluded vein graft s with large clot burdens by using significantly less urokinase and sh orter drug administration times than conventional infusion protocols. (C) 1997 Wiley-Liss, Inc.