Value of intravascular ultrasound in the assessment of coronary pseudostenosis during coronary interventions

Coronary pseudostenosis (PS) are increasingly visualized during coronary in terventions. In many patients PS are readily recognized by a characteristic angiographic pattern, but in other cases the diagnosis remains difficult. The value of intravascular ultrasound (IVUS) in the study of PS remains unk nown. In this study, IVUS was used to assess the morphologic appearance of the Vessel wall in 10 consecutive patients showing images of PS during coro nary interventions. Mean age of the group was 60 +/- 12 years and two patie nts were female. IVUS was performed with a motorized pullback system to ass ess lumen, plaque, and total Vessel cross-sectional areas. Measurements wer e performed both at the site of PS and at the distal reference segment. PS were always located on angled coronary segments. In one patient no lumen na rrowing was detected with IVUS at the site of PS, In the remaining nine pat ients, however, a very localized elliptic-shaped lumen narrowing was demons trated, As compared with the distal reference segment, coronary lumen (6.3 +/- 2.2 vs. 12.7 +/- 4.8 mm(2), P < 0.001) and total Vessel area (11.9 +/- 3.3 vs. 16.1 +/- 6.1 mm(2), P < 0.05) were smaller at the site of PS. Sever e lumen asymmetry was also documented at this site, In addition, a characte ristic image of a flattened, three-layered wall, overlying a hypoechogenic space, was visualized in five patients. This unique pattern was considered the correlate of a partial coronary intussusception. PS induced some resist ance to the advancement of catheters in two patients and temporary flow imp airment in two additional patients. However, in every case, the image of PS disappeared once the guidewire was removed. Thus, at sites with PS, IVUS a llows ruling out severe atherosclerosis and coronary dissections. In additi on, IVUS also provides important diagnostic clues, including the image of i ntussusception, for making the correct diagnosis of this benign entity. (C) 1999 Wiley-Liss, Inc.