In vivo assessment of rapid cerebrovascular morphological adaptation following acute blood flow increase
- 1 December 2008
- journal article
- Published by Journal of Neurosurgery Publishing Group (JNSPG) in Journal of Neurosurgery
- Vol. 109 (6), 1141-1147
- https://doi.org/10.3171/jns.2008.109.12.1141
Abstract
Pathological extremes in cerebrovascular remodeling may contribute to basilar artery (BA) dolichoectasia and fusiform aneurysm development. Factors regulating cerebrovascular remodeling are poorly understood. To better understand hemodynamic influences on cerebrovascular remodeling, we examined BA remodeling following common carotid artery (CCA) ligation in an animal model. Rabbits were subjected to sham surgery (3 animals), unilateral CCA ligation (3 animals), or bilateral CCA ligation (5 animals). Transcranial Doppler ultrasonography and rotational angiography were used to compute BA flow, diameter, wall shear stress (WSS), and a tortuosity index on Days 0, 1, 4, 7, 14, 28, 56, and 84. Basilar artery tissues were stained and analyzed at Day 84. Statistical analysis was performed using orthogonal contrast analysis, repeated measures analysis of variance, or mixed regression analysis of repeated measures. Statistical significance was defined as a probability value < 0.05. Basilar artery flow and diameter increased significantly after the procedure in both ligation groups, but only the bilateral CCA ligation group demonstrated significant differences between groups. Wall shear stress significantly increased only in animals in the bilateral CCA ligation group and returned to baseline by Day 28, with 52% of WSS correction occurring by Day 7. Only the bilateral CCA ligation group developed significant BA tortuosity, occurring within 7 days postligation. Unlike the animals in the sham and unilateral CCA ligation groups, the animals in the bilateral CCA ligation group had histological staining results showing a substantial internal elastic lamina fragmentation. Increased BA flow results in adaptive BA remodeling until WSS returns to physiological baseline levels. Morphological changes occur rapidly following flow alteration and do not require chronic insult to affect substantial and significant structural transformation. Additionally, it appears that there exists a flow-increase threshold that, when surpassed, results in significant tortuosity.Keywords
This publication has 33 references indexed in Scilit:
- Nascent Aneurysm Formation at the Basilar Terminus Induced by HemodynamicsStroke, 2008
- Complex Hemodynamics at the Apex of an Arterial Bifurcation Induces Vascular Remodeling Resembling Cerebral Aneurysm InitiationStroke, 2007
- Allometric scaling of wall shear stress from mice to humans: quantification using cine phase-contrast MRI and computational fluid dynamicsAmerican Journal of Physiology-Heart and Circulatory Physiology, 2006
- Dilatative arteriopathy (dolichoectasia): What is known and not knownAnnals of Neurology, 2005
- Giant fusiform intracranial aneurysms: review of 120 patients treated surgically from 1965 to 1992Journal of Neurosurgery, 1997
- A fatal, chronically growing basilar artery: a new type of dissecting aneurysmJournal of Neurosurgery, 1996
- Fusiform aneurysm of the vertebrobasilar arterial system.Stroke, 1989
- Ectasia of the basilar artery with special reference to possible pathogenesisSurgical Neurology, 1985
- Adaptive regulation of wall shear stress optimizing vascular tree functionBulletin of Mathematical Biology, 1984
- Giant fusiform aneurysm of the cerebral arteries.Stroke, 1981