Laminar wall shear stress in brain arteriovenous malformations: systematic review of literature

Background: Laminar wall sheer stress (LWSS) modulates inflammatory activity of the endothelium and may be a contributing factor in many cerebrovascular pathologies. There is a lack of consensus whether significant differences in LWSS exist between feeding vessels in brain arteriovenous malformation (bAVM) and healthy vessels. A systematic review of LWSS research in bAVM was undertaken, including the methods used and the assumptions made in determining LWSS. Methods: Ovid MEDLINE, EMBASE, and Scopus electronic databases were systematically searched from inception for articles calculating LWSS in bAVM cases. LWSS values were extracted for comparison between ipsilateral bAVM feeding arteries and healthy contralateral vessels or healthy normative data. Results: Three retrospective cohort studies were identified, reporting on 42 adult and pediatric bAVM cases. Mean LWSS (mLWSS) in healthy vessels (contralateral vessels or normative controls) typically ranged from 1.2–2.7 Pa, while mLWSS values in untreated bAVM feeding arteries typically ranged from 1.6–3.6 Pa. All studies had mixed cohorts of ruptured and unruptured cases, obscuring the relationship between LWSS and bAVM history. Conclusions: mLWSS values in healthy arteries and bAVM feeding vessels tend to be low and overlapping. Further research of high scientific and methodologic quality is necessary to improve understanding of how LWSS hemodynamics relate to bAVM formation, rupture, and treatment.