Coronary angioplasty (PTCA) through 6 French (F) guiding catheters is feasible, although acute or threatened closure following coronary artery dissections may occur. This report describes our experience with the treatment of suboptimal results in 13 patients from a population of 144 patients who had PTCA through 6F guiding catheters. Patients were treated with a new low profile autoperfusion catheter (ACS, Flowtrack40) or with Palmaz Schatz stents, advanced through 6F guiding catheters. PTCA was performed via the radial artery in 11 pts (85%) or via the femoral artery in two patients (15%). In two patients, (15%) PTCA was complicated by an dissection associated with complete loss of flow (TIMI 0) and a dissection was considered to lead to abrupt closure in the remaining 11 patients (85%), despite the presence of normal flow. A Flow-track40 perfusion catheter was successfully applied in three of four patients. In one patient a persisting dissection after restoration of flow by a perfusion catheter was treated with three Palmaz Schatz stents. Implantation of Palmaz Schatz stents was attempted as primary technique in nine patients. In one patient the stent could not cross a dissection in the proximal LAD via the radial artery. With an 8F system via the femoral artery, two stents could successfully be deployed with the stent delivery system. In another patient the stent could not be advanced across a subtotal residual stenosis in a tortuous left anterior descending coronary artery. Despite normal antegrade flow and emergency bypass surgery, this patient developed a non-Q-myocardial infarction. In the remaining patients, the clinical course was uncomplicated.(ABSTRACT TRUNCATED AT 250 WORDS)