Abstract

Background
The aim of this study was to produce an internal carotid artery (ICA) occlusion model in dogs that can be used for studying the effects of surgical revascularization procedures.
Material and Method
After left frontoparietal craniectomy, the ICA and arterial circle of the brain were coagulated and transected, letting the middle cerebral artery be perfused by the contralateral ICA by way of the rostral cerebral artery in five mongrel dogs. Magnetic resonance imaging (MRI) and brain single-photon emission computed tomography (SPECT) were performed during the first 24 to 48 hours and 7 to 10 days after the operation. Paired t and Wilcoxon matched pair tests were used for statistics (p<0.05).
Results
All the dogs had postoperative hemiparesis that returned to normal after 7 to 10 days. Early MRI showed cerebral ischemia in the left parietal cortical area extending to the subcortical white matter, sparing the basal ganglion and the internal capsule. Early brain SPECT demonstrated hypoperfusion corresponding to the same area. This area became significantly restricted to a small cortical area in late MRI and SPECT images (p<0.05).
Conclusions
It is concluded that, as symptoms resolved spontaneously, this model can be used as a "reversible ischemic neurological deficit" model for diagnostic imaging and pharmacological studies.

Keywords: Nervous System Diseases - physiopathology, Dogs, Magnetic Resonance Imaging, Cerebrovascular Circulation, Tomography, Emission-Computed, Single-Photon, Regional Blood Flow, Carotid Artery, Internal - pathology, Brain Ischemia - physiopathology