Abstract
Subarachnoid hemorrhage (SAH) resulting from the rupture of a middle cerebral artery (MCA) aneurysm frequently leads to Sylvian hematoma formation. Although several studies recommend hematoma evacuation to prevent postoperative intracranial pressure (ICP) elevation, the procedure itself is challenging. At our institution, external decompression is employed in cases in which Sylvian hematoma removal is difficult. In this study, we aimed to evaluate the effectiveness of external decompression surgery in such cases.
Methods: We retrospectively analyzed 52 patients with SAH due to ruptured MCA aneurysm treated at our institution between October 2017 and September 2024. Among these patients, 25 presented with Sylvian hematoma, which produced a mass effect on computed tomography. All patients underwent craniotomy and aneurysm clipping, with additional external decompression performed in 13 patients.
Results: Overall, 50% of the patients in whom more than two-thirds of the Sylvian hematoma was evacuated achieved a favorable outcome, defined as a modified Rankin Scale score of 0–2 at discharge. In contrast, only 33.3% of the patients in whom less than one-third of the hematoma was removed showed a favorable outcome. However, the addition of external decompression improved the favorable outcome rate to 42.9%. Notably, 33.3% of patients with severe clinical grades (World Federation of Neurological Societies: WFNS grades 4–5) undergoing external decompression surgery for poor hematoma evacuation achieved a favorable prognosis.
Conclusion: In general, Sylvian hematomas associated with SAH are more difficult to evacuate than typical intracerebral hemorrhages. Although hematoma evacuation remains the primary therapeutic objective, adjunctive external decompression may improve outcomes in cases where complete hematoma evacuation is not feasible.
