Angioscopy: a valuable tool in the deployment and evaluation of intracoronary stents.

Intracoronary stents were designed to improve balloon dilation results; however, to accomplish this, various criteria of optimal stent deployment must be met. Standard imaging techniques are neither sensitive nor specific enough for intraprocedural use in the verification of these implantation parameters. To assess the usefulness of angioscopy in the procedural and follow-up evaluations of Palmaz-Schatz and Strecker coronary stent deployment, 17 patients underwent angioscopy, 15 during stent placement and 2 during follow-up for stent restenosis. In the latter cases, thrombus formation was suspected; however, angioscopy showed tissue subtotally occluding the lumen without thrombus, so thrombolytic therapy was avoided. Similarly, among the 15 intraprocedural assessments, angioscopy disclosed intravascular thrombus unappreciated on angiography in two cases; another patient at high risk for intravascular thrombus was found not to have clot. In four patients, angioscopy disclosed residual narrowing in need of redilation at the Palmaz-Schatz stent articulation site. Thus in 9 (53%) of 17 stent patients, angioscopic findings either guided therapeutic selection or significantly modified the anticipated procedure. Angioscopy offers important information critical to the accurate placement and evaluation of intracoronary stents.

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.