Abstract: Objective To investigate the effects of body weight and length of SD rats on the carotid artery balloon injury-induced vascular stenosis model in order to provide a reference for replicating an ideal vascular stenosis model. Methods Male rats were divided into three groups based on body weight and length. The CONQUEROR^TM SC PTCA balloon catheter was employed, with a fixed balloon inflation volume of 0.2 mL to induce injury in the left common carotid artery, while the right side served as a control. As soon as surgery operation, one rat from each group was selected for Evans Blue dye verification. Fourteen days later, the injured and contra lateral common carotid arteries from remaining rats were harvested for HE staining to check the extent of stenosis. Based on these findings, six rats within the optimal range of body weight and length were selected for further validation. Results Rats with body weights ranging from 280 to 380 g (corresponding body lengths of 21.0-26.5 cm) underwent balloon catheter injury, resulting in endothelial detachment and varying degrees of stenosis in the common carotid artery. In rats weighing 280-300 g (body lengths of 21.0-22.5 cm) had severe stenosis or occlusion of the common carotid artery with thrombosis. In rats weighing 320-340 g (body lengths of 23.0-24.5 cm), the internal and external elastic plates of the common carotid artery were ruptured and the vascular morphology was abnormal. Conversely, rats weighing 360-380 g (body lengths of 25.0-26.5 cm) did not show any ruptured elastic laminae or thrombus formation in the common carotid artery, and the extent of vascular stenos in rats with a body weight of 360 g was moderate and uniform. The results of the repeated validation experiments were consistent. Conclusions Rats with a body weight range of 360 g (corresponding body length of 25.0-26.5 cm) are suitable for development of an ideal vascular stenosis model.

Key words: restenosis, angioplasty, balloon catheter, rat