Percutaneous transluminal coronary angioplasty: catheter technology and procedural guidelines.

In the April issue of the British Heart Journal de Feyter et al from the Thoraxcenter described their angioplasty experience with the monorail technique in 1000 patients.' The results were excellent with success in 920O of cases and major complications in only 3.30O* They concluded that the monorail technique is safe and effective but, in the absence of a randomised trial, were careful to avoid firm statements about how it compares with other techniques. A randomised trial would be a formidable and perhaps impossible undertaking for the reasons discussed in de Feyter et al's paper. Without this information to guide the selection of angioplasty equipment, most operators pragmatically use a limited selection of familiar catheters, experimenting with something new only if it seems to offer special advantages. New technology should be judged by its ability to improve the results of angioplasty by solving specific procedural problems. Early reports identified inability to cross the coronary stenosis as the commonest cause of failed angioplasty and this prompted the introduction of the steerable guide wire, which substantially improved matters by increasing rates of passage from 78 to 920O in the National Heart, Lung, and Blood Institute Registry report.2 There remained, however, a considerable number of cases in which, though the stenosis was crossed with the guide wire, it proved impossible to pass the stenosis with the tip of the balloon catheter either because the stenosis was too tight or because it was located distally in the coronary vessel. Manufacturers responded by developing guide wires and catheters with ever more favourable mechanical characteristics3 so that this too has become an unusual cause of failure. Attention is now being directed towards treatment of the chronically occluded vessel and success rates are already improving though there is less optimism about finding purely technological solutions to the problems of coronary reocclusion and restenosisdevelopments in pharmacology are expected to be as important as technology. This article summarises currently available angioplasty technology and attempts to provide guidelines for selection of catheters and guide wires.