DISSECTION AFTER BALLOON ANGIOPLASTY - PR EDICTION USING PREINTERVENTIONAL INTRAVASCULAR ULTRASOUND IMAGING

The purpose of this study was to examine the association between quali tative and quantitative lesion characteristics before and the incidenc e 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 imm ediately after coronary balloon angioplasty. Images were assessed for plaque composition, topography and postinterventional effects on the p laque morphology. Quantitative measurements of lumen area, total arter ial area and plaque area were performed in the dilated vessel segment. Plaque morphology was concentric in 18 lesions (44 %) and eccentric i n 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 manife sted by ultrasound imaging after balloon angioplasty. Dissection with detachment of the plaque from the underlaying wall was found in 10 les ions, plaque splitting in 9 lesions, superficial tears in 6 lesions, a nd smooth plaque contours in 16 lesions. The incidence of dissection d etected by intravascular ultrasound was significantly greater in eccen tric lesions (p = 0,03) and in stenoses with a small total arterial ar ea (p = 0.006). The incidence of dissection was significantly increase d in vessels in which balloon cross-sectional area exceeded 50 % of th e total cross-sectional vessel area as compared to those with a smalle r balloon-to-vessel ratio. Preinterventional IVUS imaging provides inf ormation about the target stenosis which can be used to assess the ris k of postinterventional dissections. In addition to the size of the ba lloon in relation to vessel cross-sectional area, the features small t otal vessel cross-sectional area and eccentric stenosis morphology in the preinterventional IVUS study predispose to an increased risk of di ssection. Further studies have to elucidate the influence of dissectio ns on late outcome after angioplasty.