Intravascular ultrasound and histology in in vitro assessment of iliac artery angioplasty

Purpose: Intravascular ultrasound (IVUS) was used to assess in vitro the mo rphologic and quantitative effects of balloon angioplasty (PTA) of the ilia c artery. Methods: Forty human iliac arteries (greater than or equal to 30% area sten osis) were studied with IVUS in vitro before and after PTA and the findings were validated with histology. Results: The sensitivity of IVUS for dissection was 24% and for media ruptu re 59%. The incidence of vascular damage was higher when the whole segment was analyzed rather than the target site alone. Dissections occurred at the thinnest region of the plaque, unrelated to plaque calcification. Followin g PTA, quantitative changes at the target site were greater compared with t he overall data derived from all cross-sections. The increase in lumen area was caused solely by an increase in vessel area. Conclusions: IVUS is sensitive in detecting dissections, which occurred irr espective of calcification at the thinnest region of the plaque. The increa se in lumen area after PTA was caused by stretching of the vessel.