Role of suture diameter and vessel insertion position in the establishment of the middle cerebral artery occlusion rat model

The aim of the present study was to explore the role of suture diameter and vessel insertion position in the preparation of the middle cerebral artery occlusion (MCAO) rat model. A total of 84 Sprague-Dawley rats (weighing 250-300 g) were randomly divided to three groups: group A (type 1.0, suture diameter 0.16-0.17 mm and tip 0.21-0.22 mm); group B (type 2.0; suture diameter, 0.22-0.23 mm; tip, 0.27-0.28 mm); and group C (type 3.0; suture diameter, 0.28-0.29 mm; and tip, 0.33-0.34 mm). The animals in each group were then subdivided into two subgroups, one of which received a nylon line inserted through the external carotid artery (ECA insertion), while the other received the nylon line through the common carotid artery (CCA insertion) subsequent to a middle or lateral neck incision. The neurological deficit score was evaluated at 4, 8, 24, 48 and 72 h post-surgery. The ischemic brain tissue was stained by 2,3,5-triphenyltetrazolium chloride (TTC) to evaluate the extent of the infarct volume. The cerebral edema rate, cerebral infarction volume rate, relative standard deviation (RSD) of the cerebral infarction rate and the success rate were also assessed. The rectal temperature, PaO2, PaCO2, pH, blood pressure and blood glucose levels were controlled and did not vary between the group types. The results suggested that suture diameter and insertion route affected the infarct volume and success rate in the establishment of the suture MCAO rat model. Furthermore, the MCAO model with a 0.22-0.23 mm diameter suture and CCA insertion route provided the highest success rate in the SD rats.