Intravascular Ultrasound Assessment of Acute Expansion of the Balloon-expandable Stent in Heavy Calcified Iliac Artery Lesions or in Lesions Resistant to Dilation by a Self-expanding Stent

Abstract

To evaluate the acute stent expansion of a balloon-expandable stent (BES) by intravascular ultrasound (IVUS) in lesions with heavy calcification or in lesions resistant to dilation by a self-expanding stent (SES). Primary stent placement using the Express LD was performed for 72 limbs in 56 patients. The BES was deployed both for ostial lesions of the common iliac artery (CIA) in 63 limbs and for additional dilation of an SES using a stent-in-stent maneuver in 9 limbs. Of the CIA ostial lesions, 71% (45 of 63) had heavy calcification. The primary endpoint was an acute stent expansion as assessed by IVUS. The ratio of the IVUS-measured minimal stent diameter (MSD) to the diameter predicted by the manufacturer's compliance chart was used as a measure of the acute stent expansion. The ratio was compared between noncalcified and calcified CIA lesions and between before and after additional placement of the BES in the case of insufficient expansion of an SES. The BES achieved 81 ± 10% of the predicted MSD in noncalcified CIA lesions and 78 ± 12% of the predicted MSD in heavy calcified CIA lesions (P = 0.346). In the 9 limbs with insufficient expansion of an SES, deployment of the BES resulted in an improvement in MSD from 39 ± 16% to 77 ± 8% of the predicted MSD (P < 0.001). Sufficient acute expansion of the BES was demonstrated in heavy calcified lesions or in lesions with insufficient expansion of an SES.