New treatment approach for chronic total occlusions of saphenous vein grafts: Thrombolysis and intravascular stents

Balloon dilation of saphenous vein graft (SVG) occlusions has a lower success rate than angioplasty of native coronary arteries. To improve this outcome, a new therapy for chronic total SVG occlusions was developed. In three aortocoronary bypass graft patients with class III-IV angina and chronic occlusion of the SVGs to the left anterior descending artery (age of occlusions: 2-24 wk, age of graft 1-13 yr), standard recanalization was achieved with a guide wire and intracoronary urokinase infusion (0.5-1.0 million unit bolus followed by 100,000 IU/hr for 11-24 hr; mean infusion time: 19.7 hr). In each patient, a residual focal stenosis (average 82.5%) was successfully dilated and stented (single 4.0 mm Palmaz-Schatz in two patients and a 3.5 mm Strecker stent in the other). All patients had complete relief of symptoms and no sequelae. During a mean 7.7 mon follow-up, 6-mon arteriographic evaluation in two patients showed minimal intra-stent narrowing (26% and 34%). In the Strecker stent patient, the device proved too small for the vein graft, leading to an 89% stent stenosis found on follow-up arteriography at 5 mon. The stent was redilated successfully with a 5% residual narrowing. After urokinase recanalization of chronic total SVG occlusions, intravascular stents may improve the long-term results seen with conventional SVG angioplasty.