Conservative versus surgical management of traumatic acute subdural hematoma: a systematic review and meta-analysis

Introduction: Acute subdural hematoma is among the most severe forms of traumatic brain injury, associated with high mortality and significant neurological morbidity. Optimal management-surgical versus conservative-remains uncertain, particularly in patients whose clinical and radiological presentation does not clearly meet established surgical thresholds. No prior meta-analysis has directly compared these strategies in the broader adult population (> 18 years). Methods: Four electronic databases (PubMed, Scopus, Web of Science, Cochrane Library) were searched from inception to February 2026. Studies were included if they involved adult patients with CT/MRI-confirmed traumatic aSDH comparing surgical (craniotomy or craniectomy) versus conservative management and reporting at least one relevant clinical or radiological outcome. Pooled estimates were calculated using random-effects models. Results: Eleven studies encompassing 3,792 patients (2,507 male) were included. Surgical patients ( n = 1,029) presented with significantly lower admission GCS scores (MD − 1.93; 95% CI [− 3.35, − 0.52]; p = 0.007), greater hematoma thickness (MD + 3.56 mm; p = 0.0009), and larger midline shift (MD + 4.83 mm; p < 0.00001) compared to conservatively managed patients ( n = 2,763). Despite a higher crude mortality in the surgical group (25.9% vs. 11.6%), pooled analysis revealed no statistically significant difference in overall mortality (RR 1.36; 95% CI [0.74, 2.50]; p = 0.32). Surgical patients had significantly longer hospital stays (MD + 6.77 days; p = 0.003). Conclusion: No statistically significant difference in mortality was observed between surgically and conservatively managed patients; however, the substantially greater baseline severity of surgically managed patients, together with the absence of patient-level adjustment, means that these observational data are insufficient to determine whether surgery reduces, increases, or has no effect on mortality. Substantial heterogeneity and absence of randomized data underscore the need for prospective trials targeting patients with intermediate clinical presentations.