I. Nigel Sinclair

Predictors, therapeutic options and long-term outcome of abrupt reclosure

To ascertain the clinical and procedural factors that relate to the occurrence and management of abrupt reclosure, data on 1,160 consecutive patients who underwent coronary angioplasty between December 1981 and December 1986 were analyzed. Abrupt reclosure occurred in 54 patients (4.7%), developing during the dilatation procedure in 43 patients (80%) and delayed by 11 +/- 2 hours after the procedure in 11 patients (20%). Patients were divided into 3 groups based on subsequent management: (1) 22 patients (40%) in whom the involved vessel was reopened by additional dilatation, (2) 14 patients (26%) in whom the involved vessel was not reopened but the patient was treated medically, and (3) 18 patients (33%) in whom abrupt reclosure was managed by emergency bypass surgery, yielding an overall emergency surgery rate of 1.6%. Patients whose abrupt reclosure was reopened were more likely to have luminal thrombus (54 vs 28%) and less likely to have extensive local dissection after dilatation (14 vs 61%; p less than 0.025) than patients undergoing emergency surgery. Patients treated medically despite continued vessel occlusion were more likely to have collateral blood flow to the occluded zone (54 vs 11%, p less than 0.01) than patients undergoing surgery. While 10 of 18 patients (56%) undergoing emergency surgery sustained a myocardial infarction, all patient subgroups appeared to do well during long-term follow-up.

Laser Balloon Angioplasty: Experimental In-Vivo and In-Vitro Studies

Important causes of suboptimal angiographic results following percutaneous transluminal coronary angioplasty (PTCA) include elastic recoil, arterial dissection, and the presence of thrombus. Although increased vasomotor tone may contribute to a reduction of luminal diameter improvement, passive recoil probably accounts for most of the latter. Typically, in most clinical series [1–4] a mean residual diameter of acute stenosis of approximately 30%, which roughly corresponds to a 50% luminal cross-sectional area stenosis, is found after successful PTCA, presumably as a result of such recoil. Intimal tears may further compromise an apparently successful PTCA procedure, even without propagation of a dissection, by local disruption of laminar flow patterns. When thrombus is associated with a lesion treated with PTCA, a poor result is frequently encountered, perhaps as a result of the difficulty in attempting to remodel this tissue with pressure and the possibility that spreading the thrombus along the luminal surface may increase the number of sites of potential propagation of the thrombus.

Laser Balloon Angioplasty: Theory And Techniques

Balloon angioplasty, while generally successful as a revascularization procedure, has the major drawbacks of abrupt reclosure and chronic restenosis. These problems may be related, at least in part, to a large thrombogenic surface and to abnormal blood flow patterns caused by disrupted vessel wall elements impinging on the lumen following angioplasty. Laser balloon angioplasty (LBA), a method whereby the vessel wall is heated during balloon inflation by a Nd-YAG laser coupled to an optical fiber terminating within the balloon, may help overcome these problems. The major effects of LBA appear to be a welding back of dissected flaps, reduction of the elastic recoil of the vessel wall, and destruction of smooth muscle cells within the wall, so that their exuberant cellular response to angioplasty is less likely to occur.