Abstract No. 482 Morphological comparison before and after coil embolization of pulmonary arteriovenous malformations on computed tomographs

Abstract

To examine morphological changes of pulmonary arteriovenous malformations (PAVMs) before and after coil embolization on computed tomographs (CT). Between October 2012 and October 2016, 7 patients (1 male, 6 females, median age 70 years) with 10 PAVMs who improved clinically after coil embolization (CE) of sac PAVMs were enrolled. Pre- and post-CE morphological comparisons included the diameter of the feeders and drainers, the sac volume, and the shrinkage rate the feeding and draining vessels. Computational fluid dynamics (CFD) analysis was performed in 3 patients. The median follow-up was 360 days (range, 26-1376 days). The average diameter before and after CE of the feeding vessel was 4.4- and 2.8 mm, of the drainage vessel it was 3.7- and 2.5 mm. The average pre- and post-CE sac volume was 211.49 mm3 (median 200.63 mm3). The average shrinkage rate of the feeders and drainers was 37.2% and 33.7%, respectively; the pre- and post-CE diameter of the feeders and drainers was significantly different (p = 0.0001). There was no statistically significant correlation between the sac volume and the shrinkage rate of the feeding- (r = -0.3108, p = 0.3820) and the draining vessels (r = 0.09978, p = 0.7839). CFD analysis showed that most of the blood flow from the feeders passed through the PAVM sac. CDF analysis of virtual CE of PAVMs indicated that feeders and drainers were subject to increased wall shear stress (WSS) and that their oscillating shear index (OSI) was increased. Comparison of pre- and post-CE CT images of PAVMs showed that after the procedure, the diameter of the feeders and drainers was significantly smaller. We think that the absence of a correlation between the sac volume and the shrinkage rate of the feeding and draining vessels is attributable to a post-CE increase in the WSS and OSI.