Objectives: To assess the short-term outcomes and identify risk factors of unfavorable outcomes in patients with ruptured pericallosal artery aneurysms (PerAA).

Methods: We analyzed the outcomes of 61 patients with ruptured PerAA (39 females and 22 males, mean age: 47 years) that were treated with microsurgery. Forty-four patients (72.1%) had a single PerAA, and 17 (27.9%) had multiple aneurysms (most commonly middle cerebral artery aneurysms). The Hunt-Hess (HH) grade was grade I in four patients (6.5%), grade II in 28 (46%), grade III in 23 (38%), and grade IV in six patients (9.5%). Various levels of depression of consciousness were observed in 20 patients (33%). Seven (12%), 13 (21%), five (38%), and 36 patients (59%) patients had Fisher scale grades of 1, 2, 3, and 4, respectively. In most cases (70.5%), PerAAs were located on the A3 segment, followed by the A2 in 28% and A4-A5 in 1.6%. Rebleeding was observed in nine patients (15%) and vasospasm in 19 (31%). Microsurgical clipping was performed in 52 patients (85%) and trapping of the aneurysm in nine (15%).

Results: Treatment results were assessed using the Glasgow Outcome Scale (GOS). At discharge, 33 (54.1%), nine (14.7%), six (9.9%), and 13 patients (21.3%) were rated as GOS5, GOS4, GOS3, and GOS1, respectively. Statistically significant (p < 0.05) risk factors for unfavorable outcomes were found to be: HH grades IV-V, a Glasgow Coma Scale score of < 12 upon admission, intracerebral hemorrhage of > 20 cm³, rebleeding, vasospasm, and early operation (in the first 72 h of rupture).

Conclusions: Early operation is preferable for patients without vasospasm and patients with HH grade I-III. In patients who present with HH grade IV-V on admission, early operation can be performed in selective cases with respect to the identified risk factors.