title: Changes in wall shear stress of cerebral arteriovenous malformation feeder arteries after embolization and surgery.
abstract: OBJECTIVE
  Wall shear stress (WSS) has been implicated as an important stimulus for vascular remodeling. The purpose of this study is to measure WSS in AVM arterial feeders using quantitative magnetic resonance angiography pre- and post-embolization/surgery.
  
  
  METHODS
  Records of patients who underwent AVM embolization and surgical resection at our institution between 2007 and 2013 and had WSS, flow rate, and vessel diameter obtained pre- and post-treatment using quantitative magnetic resonance angiography were retrospectively reviewed. WSS was compared between the feeder and contralateral artery pre- and post-embolization/surgery.
  
  
  RESULTS
  Twenty-one patients were included (mean age 34 years, 19% hemorrhagic presentation), with Spetzler-Martin grades 1 to 4. WSS, blood flow, and vessel diameter were assessed in a total of 51 feeder arteries. At baseline, mean WSS was significantly higher compared with the contralateral vessel (29.7±12.0 dynes/cm(2) versus 23.3±11.0 dynes/cm(2); P=0.007). After embolization (23.0 dynes/cm(2) versus 22.5 dynes/cm(2); P=0.78) and surgery (17.9 dynes/cm(2) versus 23.2 dynes/cm(2); P=0.09), WSS was not significantly different than in the contralateral vessel. Reduced WSS post-embolization corresponded to significantly decreased flow (338.1 mL/min versus 170.3 mL/min; P<0.001) and smaller vessel diameter (3.7 mm versus 3.5 mm; P=0.01).
  
  
  CONCLUSIONS
  Enlargement of cerebral AVM arterial feeders is insufficient to compensate for increased blood flow, creating high WSS. After treatment, flow diminishes and so WSS and vessel diameter concomitantly decrease. Thus, WSS plays a pivotal role in vascular remodeling that may be exploited to monitor AVM response to treatment or understand other high-flow vascular pathologies.
authors: From the Department of Neurosurgery, University of Illinois at Chicago. alaraj@uic.edu.
authors: Ali
authors: A
authors: Alaraj
authors: From the Department of Neurosurgery, University of Illinois at Chicago.
authors: Sophia F
authors: SF
authors: Shakur
authors: From the Department of Neurosurgery, University of Illinois at Chicago.
authors: Sepideh
authors: S
authors: Amin-Hanjani
authors: From the Department of Neurosurgery, University of Illinois at Chicago.
authors: Hassan
authors: H
authors: Mostafa
authors: From the Department of Neurosurgery, University of Illinois at Chicago.
authors: Sajeel
authors: S
authors: Khan
authors: From the Department of Neurosurgery, University of Illinois at Chicago.
authors: Victor A
authors: VA
authors: Aletich
authors: From the Department of Neurosurgery, University of Illinois at Chicago.
authors: Fady T
authors: FT
authors: Charbel
mesh_terms: D000293:Adolescent; D000328:Adult; D002536:Cerebral Arteries / Q000473:pathology*; D002560:Cerebrovascular Circulation; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000473:pathology* / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D012189:Retrospective Studies; D033081:Shear Strength; D013314:Stress, Mechanical; D055815:Young Adult
keywords: arteriovenous malformation; cerebral; embolization; magnetic resonance angiography; shear stress