Challenging the creation of middle cerebral artery occlusion in rats and factors causing its failure

Stroke is a cause of death and disability in the world. Animal research needs animal models that are as similar as possible to the pathophysiological processes that occur in humans. The established ischemic stroke model is the middle cerebral artery occlusion (MCAO) model. The creation of this model requires sophisticated equipment and precision. Our study aims to describe the MCAO modeling procedure using simple tools and to identify causes of death. Creation of ischemic stroke animal models with MCAO procedure with simple equipment and using monofilament nylon suture 4.0 to clog the middle cerebral artery and reperfusion for 90 minutes. Neurological deficits are clinically tested with Bederson parameters after one hour of MCAO. 2.3.5 triphenyl tetrazolium chloride staining was performed to determine the area of infarction after 24 hours of MCAO. The histological picture is examined with hematoxylin-eosin staining. Two rats succeeded in modeling ischemic stroke, two rats failed in modeling ischemic stroke, two rats died during preparation, four rats died during surgery, and 10 rats died several hours after occlusion. The most common cause of death was bleeding from 4.0 nylon sutures, which are too long to pass through the middle cerebral artery, thereby puncturing the blood vessels. When creating a model of ischemic stroke, it is essential to consider the elements that contribute to rat failure and death.