P3C-7 Microvascular Imaging of Chronic Total Occlusions

Chronic total occlusion (CTO) is a condition that occurs when an artery is completely occluded for > 1 month. The ability of ultrasound to detect microvasculature in CTOs is the focus of this study. The development of a superficial porcine femoral model of CTO by percutaneously placing a dissolvable polymer plug in the artery to promote thrombosis has provided a means by which to examine the formation and characteristics of these channels. The arteries, which are ~2-3 mm in diameter, accurately model thrombosis in CTO arteries. Studies have been performed on n = 8 porcine arteries. 3D power Doppler (PD) datasets from the arteries were acquired in vivo using a Vevo 770 system operating at 40 MHz at 1 week and 8 week timepoints. The scanning was performed transcutaneously through ~2 mm of skin to the artery. The formation of microvessels >100 mum in diameter were detected in vivo, as 6 of the 8 arteries self recanalized. At points where PD imaging suggested the presence of microvasculature, PW Doppler profiles were taken showing pulsatile flow rates of ~2 cm/s. The results were correlated with histology. The ability to detect microvessels in vivo with ultrasound suggests a potential method for real time guidance of CTO interventions