Aneurysmal subarachnoid hemorrhage (aSAH) accounts for approximately 5% of all strokes and has a significant social and family impact due to its low age of onset and severity. Cerebral CV (cerebralvasospasm, CV) is the most common complication after aSAH, with an incidence of up to 70%, with symptomatic cerebral ischemia occurring in up to 36% of patients, increasing mortality by 1.5 to 3 times. Those with clinical symptoms and transcranial Doppler (TCD) examinations suggesting possible CV can eventually be diagnosed definitively by whole brain angiography. The use of TCD to measure cerebral blood flow velocity (CBFV) can detect CV after SAH, and TCD has the same sensitivity and specificity as angiography. Therefore, TCD is a good method to evaluate the hemodynamic differences between different treatments for aSAH. Patients with aSAH should undergo neurosurgical clamping or endovascular tamponade to reduce the risk of rebleeding. However, there is no definitive conclusion on the choice of modality for aneurysm management, and there are few data on hemodynamic comparisons after different approaches to aSAH, especially a lack of relevant data in non-operated patients. In order to evaluate the effect of different treatment methods on CV after aSAH, this study used TCD to continuously monitor cerebral hemodynamics in patients with aSAH within 14 d of onset and analyze the effect of different treatment modalities on CV. 1. Subjects and methods Inclusion criteria ① Age ≥ 18 years; ② Comply with the International Classification of Diseases (ICD), 10th edition, diagnosis code 430.0 (SAH) [9]; ③ Complete whole brain angiography (digital subtraction angiography, DSA) within 72 h; ④ Patients in the surgical group within 72 h of ⑤ Good temporal window. Exclusion criteria ① DSA confirmed non-aneurysmal SAH; ② unclear time of onset or more than 72 hours after arrival; ③ poor temporal window; ④ large intracranial and extracranial arterial stenosis detected by TCD and/or DSA; ⑤ serious medical complications. 2. Results Baseline information The 45 patients enrolled in the study completed all 12 TCD examinations and 90-d follow-up. Analysis of baseline information revealed no significant differences (P>0.05) in demographics, past history (hypertension, diabetes, hyperlipidemia, smoking, alcohol abuse and previous history of SAH) among the three groups. There was no significant difference in clinical and imaging grading between the conservative, occlusion and clamping groups (P>0.05). Fourteen of the 45 patients had DSA-confirmed responsible aneurysms, but did not undergo aneurysm occlusion because some of the responsible aneurysms were located at the MCA bifurcation with deep penetrating branches emanating from above supplying functional areas of the brain; the patients were more severely ill with Hunt-Hess grading over grade III; or refused surgical treatment. Two of these patients died from rebleeding from ruptured aneurysms.