Abstract
Haemodynamic changes in cerebral circulation are associated with the natural ageing process and associated pathology, leading to the development of incapacitating neurological and neurovascular diseases. Due to inherent biological limitations, current literatures mostly aimed at studying the correlation descriptively or quantifying the relationship in vitro or using computational models. In this paper, a model of a carotid-jugular fistula in the rat was used to create a haemodynamic insult to the intracranial arterial circulation and subsequent venous drainage. An arterial-venous (AV) fistula was created in 12 rats, 6 of which are normotensive Wistar-Kyoto strain (WKY) and the rest spontaneously hypertensive strain (SHR) with an additional 6 in each strains designed as controls without previous surgery. After 4 weeks of convalescence, all 24 rats were euthanised and their cerebral circulation was examined histomorphologically. We confirmed an intrinsic morphological difference between normotensive WKY and hypertensive SHR and found a modest but significant arterial shrinkage in both strains induced with AV fistula. We also reported that alterations in blood flow are also associated with marked extracellular matrix changes. We concluded that the model was suitable for studying the relative contributions of altering haemodynamic patterns and venous drainage on cerebrovascular changes. We also found that hypertension modulated cerebral vascular changes in addition to disrupted blood flow.
Highlights
Chronic changes in cerebral haemodynamics are associated with morphological alterations in cerebral vasculatures [1]
Following AV fistula induction, SHR developed greater shrinkage compared with Wistar-Kyoto strain (WKY) and the left internal carotid artery (ICA), middle cerebral artery (MCA) and anterior cerebral artery (ACA) directly proximal to the AV fistula shrank more compared with their contralateral side
Consideration of Previous Studies Our study focused on relatively larger arteries immediately proximal to the fistula and we found that ICA, MCA, and ACA shrank following AV fistula with vessels of SHR shrank more compared with WKY
Summary
Chronic changes in cerebral haemodynamics are associated with morphological alterations in cerebral vasculatures [1]. Cerebrovascular research has used a range of experimental models to unravel the causal relationship between haemodynamic changes and pathophysiological adaptation of cerebral vasculature in various diseases. To investigate the underlying pathophysiology, an experimental carotid-jugular fistula, for the purpose of altering cerebrovascular circulation, was used in the present study. Disruption of cerebral circulation secondary to an AV fistula has been shown to greatly elevate the risk of developing co-morbidity, such as dysplastic aneurysms, in the presence of a previous or currently untreated cerebrovascular disease, leading to even higher mortality in cerebral vascular patients [13]. The aim of this study is to report a rat model of AV fistula that has incidental high occurrence of vascular dilatation in the circle of Willis proximal to the AV fistula and to further characterise the morphological and pathological features of the shrunk cerebral arteries. We further investigated the summative effects of hypertension in conjunction to altered haemodynamic changes on the vascular changes in the model
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
