DIRECT CORONARY STENTING WITHOUT PREDILATATION - A NEW THERAPEUTIC APPROACH WITH A SPECIAL BALLOON CATHETER DESIGN

Coronary stenting is the primary therapeutic option for many coronary lesions, after the risk of subacute stent thrombosis and bleeding comp lications has been reduced by antithrombotic regimens and improved ste nt expansion. It would be desirable to shorten the procedure and the d uration of ischemia, and to reduce the risk of ischemic complications during balloon inflation by implanting the stent without previous dila tation of the lesion. This is not possible with the presently availabl e stent delivery systems. This new therapeutic concept was tested with a specially designed balloon catheter, on which slotted-tube stents c an be fixed between two conical radiopaque markers, Sixty-one patients elegible for angioplasty underwent direct stent implantation without predilatation. Four procedures were performed for acute myocardial inf arction, and two as high-risk PTCA. Single slotted-tube stents (Palmaz -Schatz, NIR, or JOStent) of 14-16-mm length were mounted between the conical radiopaque markers of a special balloon which provided a fixat ion for the crimped stent, The direct implantation was successful in 8 0% of all patients, while in 10% the stent could be deployed after pre dilatation of the lesion. In 10% of lesions a stent could not be impla nted with this and any other delivery system, When patients with succe ssful direct stenting were compared with those with indirect (after pr edilatation) or unsuccessful stent deployment, the presence of angiogr aphically visible calcification was higher in the unsuccessful cases ( 75% vs. 19%; P < 0.01), and the patients were older (72 +/- 8 vs. 61 /- 12 years; P < 0.01), Radiation exposure time was only 8.7 +/- 5.1 m in as compared with 12.6 +/- 7.6 min in conventional stent procedures with predilatation (P < 0.05). The number of balloons used per lesion was also lower than with conventional stenting. Stent dislocation was observed in 5%, and no embolization occurred. The new therapeutic appr oach of direct stenting without predilatation proved to be a safe and successful procedure in this initial series of coronary angioplasties. When calcified coronary lesions are avoided, it provides a way to rat ionalize stent implantation with shorter radiation exposure times, few er balloons, and the potential advantage of fewer ischemic complicatio ns as no balloon predilatation is required. (C) 1998 Wiley Liss, Inc.