To establish a rat model of subarachnoid hemorrhage (SAH) using an internal carotid artery (ICA) puncture technique that is technically straightforward and clinically relevant.

Forty 7-8-week-old Sprague Dawley (SD) rats were randomly allocated to a model group and a sham-operated group, with 20 rats in each group. After 1 week of adaptive feeding, surgical procedures were performed. In the model group, the SAH model was constructed via endovascular ICA puncture. Under anesthesia, the common carotid artery, ICA, and external carotid artery were exposed. A pre-prepared 4-0 polypropylene suture was inserted through the stump of the external carotid artery to the bifurcation of the ICA. The suture tip was then advanced to pierce the arterial wall​ at the bifurcation, held for 3 seconds, and this puncture process was repeated 2–3 times. Hemostasis was achieved by electrocoagulation, followed by incision suturing. In the sham-operated group, the suture was immediately withdrawn after reaching the bifurcation, and all other steps were identical to those of the model group. The modified Sugawara scoring system was used to evaluate the severity of hemorrhage at 72 hours after modeling. The modified Garcia scoring system was applied to assess the neurological function of rats in both groups at the same time points. Independent sample t-test was used for intergroup comparison.

Eighteen rats survived in the model group, with a survival rate of 90.0%. Among the survivors, 17 rats (94.4%) achieved a modified Sugawara score ≥8, comprising 11 cases of severe hemorrhage and 6 cases of moderate hemorrhage. Compared with the sham-operated group, the model group showed significant neurological impairment at all time points (24 hours: 14.40±1.43 vs 16.20±1.23, t=3.019, P=0.007; 48 hours: 12.40±0.97 vs 16.60±1.18, t=8.737, P＜0.001; 72 hours: 7.80±1.81 vs 17.20±1.14, t=13.890, P＜0.001), with the most severe neurological impairment observed at 72 hours after modeling.

The modified ICA puncture technique for establishing the SAH model in this study demonstrates high reproducibility, technical simplicity, and a high success rate. This model effectively mimics the pathophysiology of aneurysmal SAH.