Surgical evacuation for chronic subdural hematoma: Predictors of reoperation and functional outcomes

BACKGROUND: Although chronic subdural hematoma (CSDH) incidence has increased, there is limited evidence to guide patient management after surgical evacuation. OBJECTIVE: To identify predictors of reoperation and functional outcome after CSDH surgical evacuation. METHODS: We identified all patients with CSDH between 2010 and 2018. Clinical and radiographic variables were collected from the medical records. Outcomes included reoperation within 90 days and poor (3–6) modified Rankin Scale score at 3 months. RESULTS: We identified 461 surgically treated CSDH cases (396 patients). The mean age was 70.1 years, 29.7 % were females, 298 (64.6 %) underwent burr hole evacuation, 152 (33.0 %) craniotomy, and 11 (2.4 %) craniectomy. Reoperation rate within 90 days was 12.6 %, whereas 24.2 % of cases had a poor functional status at 3 months. Only female sex was associated with reoperation within 90 days (OR = 2.09, 95 % CI: 1.17–3.75, P = 0.013). AMS on admission (OR = 5.19, 95 % CI: 2.15–12.52, P < 0.001) and female sex (OR = 3.90, 95 % CI: 1.57–9.70, P = 0.003) were independent predictors of poor functional outcome at 3 months. CONCLUSION: Careful management of patients with the above predictive factors may reduce CSDH reoperation and improve long-term functional outcomes. However, larger randomized studies are necessary to assess long-term prognosis after surgical evacuation.