Coronary angioplasty--unstable lesions and prolonged balloon inflation time.

One of the most important complications after percutaneous transluminal coronary angioplasty is the abrupt closure of the dilated vessel (unstable lesion). The treatment of choice for this complication is a new dilation, but unfortunately many of these cases require immediate surgery to avoid an acute myocardial infarction. Prolonged balloon inflations have been suggested to control this kind of complication. In order to discover the effect of prolonged inflations on the incidence of unstable lesions we studied 439 patients enrolled in two groups: Group I (195 patients and 207 arteries) treated with balloon inflation time less than 40 sec per session and Group II (244 patients and 265 arteries) treated with inflation time over 60 sec since the first series of inflations. As a result there was a significantly lower incidence of unstable lesions and immediate surgery in Group II without an increase in the incidence of diffuse ischemia.