A novel embolic stroke model resembling lacunar infarction following proximal middle cerebral artery occlusion in beagle dogs

• Published in: Journal of neuroscience methods Vol. 209; no. 1; pp. 90 - 96
• Main Authors: Liu, Sheng, Hu, Wei-Xing, Zu, Qing-Quan, Lu, Shan-Shan, Xu, Xiao-Quan, Sun, Lei, Zhou, Wei-Zhong, Shi, Hai-Bin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 30.07.2012
• Subjects: Anastomosis; Animal models; Animals; Beagle dogs; Blood coagulation; Brain; Cerebral blood flow; Cerebral infarction; Computed tomography; Diffusion weighted imaging; Disease Models, Animal; Dogs; Embolism; Embolization; Etiology; Female; Infarction, Middle Cerebral Artery - complications; Infarction, Middle Cerebral Artery - pathology; Ischemia; Lacunar infarction; Magnetic Resonance Angiography; Magnetic Resonance Imaging; Male; Middle cerebral artery occlusion; Nervous system; Neuroimaging; Stroke; Stroke, Lacunar - etiology; Stroke, Lacunar - pathology; Thrombus; Lacunar infarction; Diffusion weighted imaging; Thrombus; Middle cerebral artery occlusion; Beagle dogs
• ISSN: 0165-0270; 1872-678X
• DOI: 10.1016/j.jneumeth.2012.06.009

► The white thrombus of 1.7mm in diameter is found to be optimal for producing segmental occlusions in the proximal MCA trunk through ipsilateral ICA injection. ► We generate an ischemic model which can recapitulate the radiologic and histologic changes in lacunar infarcts in beagle dogs. ► We are the first group to study the time course of lacunar infarction in acute phase using diffusion weighted imaging in beagle dogs. It is estimated that lacunar infarcts account for 25% of all ischemic strokes, but its exact etiology is still on debating. The existing controversies include whether the embolisms can indeed cause lacunar stroke in humans or animal models. We hypothesized that lacunar infarction can be induced by the proximal middle cerebral artery (MCA) segmental occlusion involving the orifices of lenticulostriate arteries in animal models, which have abundant distal cerebral collateral anastomosis. Our work here establishes a proximal MCA occlusion model using thrombi (autologous blood clots about 1.7mm in diameter and 5mm in length) in 8 beagle dogs, evaluates the progression of ischemic lesions at 30min interval within 6h after embolization using the diffusion weighted imaging (DWI), and discusses the potential mechanisms of lacunar infarction. Our results indicate that the left proximal MCAs can be successfully occluded in all dogs using interventional single-thrombus method. The small solitary or multiple ischemic lesions shown in DWI were observed in the deep brain area, with the mean detecting time of 1.21±0.45h using DWI and diameter of 6.62±0.60mm in 6h-DWI after procedure. In conclusion, our method established an ischemic model which can recapitulate the radiologic and histologic changes in lacunar infarcts, suggesting that emboli can cause lacunar infarcts in animal model.