Abstract W P59: Hemodynamic Changes in Wall Shear Stress in Arteriovenous Malformation Feeding Vessels Post Embolization
Objective: Arterio-venous malformations (AVM) feeders are known to remodel with time: increase in diameter when the AVM is present and decrease after the AVM is treated. In this study we used quantitative magnetic resonance angiography (QMRA) to evaluate changes in WSS, flow, and diameter of feeder vessels pre and post treatment with endovascular embolization/ surgery.
Methods: 55 patients with AVM were evaluated with QMRA on presentation, 19 patients had QMRA post embolization (1-8 sessions), and 13 post-surgical resection. WSS, flow, and diameter of proximal feeder vessels (MCA, PCA and/or ACA) and their contralateral counterparts were derived from QMRA. These parameters were studied at baseline and compared between the feeder and contralateral artery pre and post embolization/surgery.
Results: At baseline, WSS in feeder vessels (n=66) was greater than in the corresponding contralateral vessel (33.55 Dyne/cm2 vs. 24.76 Dyne/cm2; P<0.0001). These corresponded to a higher flow (296.7mL/min vs. 164.5mL/min; P = 0.0002) as well as a larger diameter (3.643mm vs. 3.257mm; P=0.0002). For embolized AVMs (n=28 feeder vessels), at the conclusion of final embolization, there was a drop in WSS (33.56 Dyne/cm2 to 22.97 Dyne/cm2; P =0.0003), flow (370mL/min to 176 mL/min; P = 0.0005), and diameter in (3.77mm to 3.522mm; P=0.0438) in feeder vessel. No significant change was seen in WSS in the contralateral vessel (23.2mm to 22.85mm; P =0.8770) post embolizations. The difference in WSS between the feeder and contralateral vessel became non-significant post embolization (22.97 Dyne/cm2 vs. 22.85 Dyne/cm2; P=0.8926). As compared to baseline, WSS dropped after surgery from 32.72 Dyne/cm2 to 20.5Dyne/cm2 (P= 0.0007).
Conclusion: Arteriovenous malformation feeding vessels are subjected to a higher WSS secondary to higher blood flow. The feeders demonstrate a corresponding enlargement in diameter, as a presumed compensatory response to the high flow. However, the vessel enlargement is insufficient to normalize the WSS at baseline. There was decrease in diameter of the feeder vessel and normalization of the WSS post reduction of blood flow with embolization/surgery.
Author Disclosures: A. Alaraj: Research Grant; Modest; NIH. Consultant/Advisory Board; Modest; Cordis-Codman. S. Amin-Hanjani: Other Research Support; Modest; GE Healthcare (no direct funds); Vasol Inc (no direct funds). Research Grant; Significant; NIH/NINDS. H. Mostafa: None. S. Khan: None. V. Aletich: Research Grant; Modest; Micrus. Consultant/Advisory Board; Modest; Cordis-Codman. F. Charbel: Ownership Interest; Significant; VasSol. Inc.. Consultant/Advisory Board; Modest; Transonic..
- © 2014 by American Heart Association, Inc.