Pulling wire to avoid misinsertion of filament and vascular damage improves ischemic stroke models' success rate and repeatability

Abstract

Background: Middle cerebral artery occlusion (MCAO) ischemia-reperfusion in rats is a commonly used in vivo model in stroke research, but the problems of long time-consuming, unstable neurological injury and high mortality are not conducive to an experimental animal study. In this study, the success rate of the MCAO model in rats was improved by changing the surgical approach and giving preoperative as well as postoperative care support. Methods: Place A-wire below the common carotid artery (CCA) to ligate the proximal end of the CCA, B-wire to fix the filament, and C-wire to pull the filament through the bifurcation of the internal carotid artery (ICA) and the external carotid artery (ECA). After temporarily clamping the ICA, insert the filament into the CCA incision, then drag the C-wire to reduce the angle between the CCA and the pterygoid artery (PPA) to avoid filament insertion into the PPA. Push forward the head of the filament to the middle cerebral artery (MCA), ventral thalamic artery (VTA), and anterior choroidal segment to block the blood supply. Neurological function scoring, triphenyltetrazolium chloride (TTC) staining and Nissl staining were applied to evaluate the model success or failure, the infarct area and neuro damage. Results: Compared with the traditional Zea longa mapping method, our method significantly reduced modeling time and surgical trauma and improved postoperative survival rate and success rate. Furthermore, our method is more consistent in terms of infarct area, and there was a significant reduction in Nissl bodies. Conclusions: The wire-lifting method pulls the vessel, reduces the angle between the CCA and the PPA, facilitates the insertion of the filament into the MCA to avoid the accidental insertion of the filament into the PPA, reduces the surgical trauma, and saves the model preparation time, which can effectively improve the survival rate and modeling success rate.