[Dissection following balloon angioplasty: predictive possibilities using pre-interventional intravascular ultrasonography].

The purpose of this study was to examine the association between qualitative and quantitative lesion characteristics before and the incidence of dissection after balloon angioplasty as assessed by intravascular ultrasound imaging. Thirty-seven patients (5 women, 32 men, aged 60 +/- 9 years) with 41 dilated lesions were examined with a 3.5 F, 20 MHz rotational tip intravascular ultrasound imaging system before and immediately after coronary balloon angioplasty. Images were assessed for plaque composition, topography and postinterventional effects on the plaque morphology. Quantitative measurements of lumen area, total arterial area and plaque area were performed in the dilated vessel segment. Plaque morphology was concentric in 18 lesions (44%) and eccentric in 23 lesions (56%). Fourteen lesions (34%) showed no calcification, 15 lesions (37%) were superficially and 12 lesions (29%) were deeply calcified. Four distinct changes of the plaque morphology were manifested by ultrasound imaging after balloon angioplasty. Dissection with detachment of the plaque from the underlaying wall was found in 10 lesions, plaque splitting in 9 lesions, superficial tears in 6 lesions, and smooth plaque contours in 16 lesions. The incidence of dissection detected by intravascular ultrasound was significantly greater in eccentric lesions (p = 0.03) and in stenoses with a small total arterial area (p = 0.006). The incidence of dissection was significantly increased in vessels in which balloon cross-sectional area exceeded 50% of the total cross-sectional vessel area as compared to those with a smaller balloon-to-vessel ratio. Preinterventional IVUS imaging provides information about the target stenosis which can be used to assess the risk of postinterventional dissections. In addition to the size of the balloon in relation to vessel cross-sectional area, the features small total vessel cross-sectional area and eccentric stenosis morphology in the preinterventional IVUS study predispose to an increased risk of dissection. Further studies have to elucidate the influence of dissections on late outcome after angioplasty.