Abstract
Background: Aneurysmal subarachnoid hemorrhage (aSAH) remains a devastating neurological condition, with patients presenting with poor-grade aSAH having a particularly limited potential for recovery. Data on outcome trajectories after microsurgical clipping in this subgroup are scarce. The objective of this study was to analyze the functional outcomes in patients with poor-grade aSAH treated with microsurgical clipping, and to identify clinical factors associated with recovery. Methods: This retrospective study included 38 patients (median age 55 years; 60.5% female) with World Federation of Neurosurgical Societies (WFNS) grades 4-5, who underwent microsurgical clipping at a single tertiary care centre between 2016 and 2023. Functional outcome was assessed using the modified Rankin Scale (mRS) at hospital discharge and 6 months follow-up, and functional outcome was analyzed in relation to clinical variables (delayed cerebral ischemia (DCI), intracerebral hemorrhage (ICH), initial seizures, the need for decompressive craniectomy) using correlation and group comparison analyses. Results: The indication for microsurgical clipping was primarily driven by the need for ICH evacuation (50%) or by aneurysm configuration (47.5%). Microsurgical aneurysm clipping was performed on the day of hemorrhage in 25 patients (65.8%), with 16 patients (42.1%) undergoing immediate surgery following direct transfer from the emergency department to the operating theatre. ICH was present in 60.5% and IVH in 92.1%. Decompressive craniectomy was performed in 42.1%. DCI occurred in 21.6% of patients. In-hospital mortality was 15.8%, increasing to 22.6% at 6 months follow-up. Good functional outcome (mRS 0-2) was observed in 10.5% of patients at discharge and improved to 25.8% at 6 months. At hospital discharge, higher mRS scores were associated with the need for immediate aneurysm repair (p = 0.04), primary decompressive craniectomy (p = 0.02), and DCI (p = 0.006). Primary decompressive craniectomy (p = 0.04), reflecting greater disease severity, and DCI (p = 0.002) remained associated with worse functional outcome at 6 months. Conclusions: In poor-grade aSAH patients undergoing microsurgical clipping, mortality remains substantial; however, functional recovery may extend beyond hospital discharge. The need for immediate surgical intervention and primary decompressive craniectomy likely reflects a particularly severe hemorrhagic burden in patients and is associated with worse early functional outcomes, whereas DCI remains an important factor in overall functional recovery.