Introduction Clip ligation of ruptured aneurysm is more commonly associated with vasospasm compared to endovascular embolization. Here, we examine if this relationship holds true for middle cerebral artery (MCA) aneurysms, given the difference in operative technique and dissection required for their clipping.

Methods A retrospective cohort study was performed of aSAH patients with ruptured anterior circulation aneurysms admitted to a tertiary care center between January 1, 2012 and March 31, 2019. Patients were grouped based on aneurysm; MCA vs. other anterior circulation aneurysms (non-MCA) and the type of procedure performed (endovascular embolization vs open clip ligation). Baseline characteristics, rate of radiographic vasospasm, delayed cerebral ischemia (DCI),and clinical outcomes were compared.

Results 712 patients were included for analysis, 109 (15.3%) MCA aneurysms and 603 (84.7%) non-MCA aneurysms. In the MCA group, 75 (68.8%) of patients underwent clip ligation compared with 147 (24.4%) patients in the non-MCA group. Baseline demographics, Hunt-Hess Score, and modified Fischer Score were comparable in both groups for the clip and endovascular cohorts.

Peri-procedural radiographic ischemia was increased in both clip ligation cohorts (56.4% vs. 6.7% in the non-MCA cohort and 52% vs 8.8% in the MCA cohort, p<0.01). The rate of radiographic vasospasm was significantly higher in the surgical, non-MCA cohort (57.1% vs. 43.8%, p<0.01). In the MCA cohort, no difference was detected in the rate of spasm between the surgical and endovascular groups (57.3% vs 52.9%,p=0.67). This dichotomy held true when examining only the patients with higher Hunt-Hess or Modified Fischer Scores. In terms of vasospasm intervention, the non-MCA patients treated with clip ligation were more likely to undergo endovascular vasospasm treatment (16.3% vs 8.5%, p<0.01). In the MCA cohort, coil embolization patents were more likely to undergo endovascular vasospasm treatment (23.5% vs 6.7%, p=0.01).

Radiologic delayed cerebral ischemia was more common in patients treated by clipping in the non-MCA cohort (17.7% vs 11%, p=0.03), but not in the MCA patients (9.3% vs. 20.6%, p=0.1). Length of ICU stay did not differ between the groups. Endovascularly treated patients in both groups were more likely to be discharged home and have a discharge modified Rankin Score(mRS)2 (p<0.01). 90-day mRS2 was more common in the embolization group compared to surgery for non-MCA patients (87.5% vs. 84.9%,p=0.04), but was similar in the MCA cohort (75% vs. 89%, p=0.15).

Conclusions In this retrospective cohort study, patients with ruptured anterior circulation, non-MCA aneurysms treated with clip ligation were more likely to develop vasospasm and DCI compared with endovascular treated patients. This relationship did not hold true for MCA aneurysms as no difference in vasospasm or DCI was identified between patients treated by coiling versus clipping.

Disclosures F. Akbik: None. J. Lamanna: None. Z. Bernstein: None. R. Greenberg: None. A. Alawieh: None. F. Tong: None. C. Cawley: None. O. Samuels: None. O. Sadan: None. B. Howard: None. J. Grossberg: None.