Hemodynamic effects of intraoperative anesthetics administration in photothrombotic stroke model: a study using laser speckle imaging

Abstract

Background Previous neuroimaging studies have shown the hemodynamic effect of either preconditioning or postconditioning anesthesia in ischemic stroke model. However, the anesthetic effect in hemodynamics during and immediately after the stroke modeling surgery remains unknown due to the lack of appropriate anesthesia-free stroke model and intraoperative imaging technology. In the present study, we utilized our recently developed photothrombotic model of focal cerebral ischemia in conscious and freely moving rats, and investigated transient hemodynamic changes with or without isoflurane administration. Laser speckle imaging was applied to acquire real-time two-dimensional full-field cerebral blood flow (CBF) information throughout the surgical operations and early after.ResultsSignificantly larger CBF reduction area was observed in conscious rats from 8 min immediately after the onset of stroke modeling, compared with anesthetized rats. Stroke rats without isoflurane administration also showed larger lesion volume identified by magnetic resonance imaging 3 h post occlusion (58.9%), higher neurological severity score 24 h post occlusion (28.3%), and larger infarct volume from 2,3,5-triphenyltetrazolium chloride staining 24 h post occlusion (46.9%).ConclusionsOur results demonstrated that the hemodynamic features were affected by anesthetics at as early as during the stroke induction. Also, our findings about the neuroprotection of intraoperative anesthetics administration bring additional insights into understanding the translational difficulty in stroke research.

Real-time quantitative monitoring of cerebral blood flow by laser speckle contrast imaging after cardiac arrest with targeted temperature management

“…Meanwhile, with inexpensive and relatively simple setup, our newly developed laser speckle contrast imaging (LSCI), an emerging neuroimaging technique, quantifies blood flow velocity, blood volume, vessel dilatation, constriction responses, and deoxy-hemoglobin saturation changes. [7][8][9][10][11] The feasibility and sensitivity of LSCI have been validated in the intraoperative CBF assessment during neurosurgery, affording the advantages of visualization and measurement of relative changes in CBF. 12,13 Despite debate over optimal maintenance temperatures, targeted temperature management (TTM) remains the most effective means of neuroprotection in clinical trials of CA.…”

Structural and Functional Remodeling of the Brain Vasculature Following Stroke

“…In addition, the choice of anesthetic regimen is crucial when performing stroke surgery in rodents, as it can strongly influence CBF and stroke outcome, and may contribute to translational failure ( O’Collins et al, 2006 ). For instance, isoflurane is a potent vasodilator with neuroprotective effects ( Tsuda, 2010 ; Gaidhani et al, 2017 ; Jiang et al, 2017 ; Lu et al, 2017 ) via modulation of eNOS activity ( Kehl et al, 2002 ; Krolikowski et al, 2006 ), which strongly confounds results. Ketamine/Xylazine (K/X) anesthesia affects baseline CBF to a lesser extent, but has also been shown to modulate eNOS ( Chen et al, 2005 ).…”

Development of a photochemical thrombosis investigation system to obtain a rabbit ischemic stroke model

“…For cerebrovascular information in localized photothrombotic stroke, high-resolution mesoscale imaging tools are required. Several studies suggested the possibility that laser speckle vascular imaging can provide information on vascular changes and occlusion of surface capillaries for photothrombotic stroke 30,[41][42][43] . Photoacoustic vascular imaging, which has a larger depth-of-imaging than laser speckle imaging, can also be applied as an analytical tool for capillary changes and occlusion during and after the investigation of photochemical thrombosis [44][45][46] .…”