Intraoperative hematoma volume can predict chronic subdural hematoma recurrence.

Background: We routinely measured the exact chronic subdural hematoma (CSDH) volume during single burr hole surgery. To date, several risk factors have been reported for CSDH recurrence, including sex, hematoma volume and degree of midline shift calculated from computed tomography, use of anticoagulants or antiplatelet medications, and alcohol consumption habits. The aim of this study was to clarify whether hematoma volume, in conjunction with other factors, can predict recurrence.

Methods: We retrospectively reviewed the clinical data of 194 consecutive patients with CSDH who underwent single burr hole surgery. The risk factors for recurrence were analyzed based on patients' sex, age, bilaterality, existence of apparent trauma history, exact intraoperative hematoma volume, and various clinical factors, including preoperative anticoagulant/antiplatelet intake.

Results: Recurrence occurred in 22 patients (11.3%). Multivariate logistic regression analysis revealed that intraoperative hematoma volume was an independent risk factor for CSDH recurrence (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.01-1.02, < 0.001), in addition to sex (male) (OR 9.25; 95% CI, 1.00-84.8; = 0.049) and diabetes mellitus (DM) (OR: 3.97, 95% CI, 1.34-11.7, = 0.013). Based on receiver operating characteristics analysis, the cutoff value of the hematoma volume predicting CSDH recurrence was 150 ml (sensitivity and specificity of 72.7% and 72.1%, respectively; area under the curve: 0.7664, 95% CI: 0.654-0.879, < 0.001). Of these, a hematoma volume ≥150 mL was the strongest independent risk factor for recurrence according to multiple regression (OR: 8.98, 95% CI: 2.73-29.6, < 0.001) and Cox regression analysis (hazard ratio: 3.05, 95% CI: 1.18-7.87, log-rank = 0.0046, = 0.021). Follow-up periods after surgery were significantly longer for cases with recurrence than for non-recurrence cases (24.8 ± 11.5 vs. 15.9 ± 9.7 days), and the recurrence prediction cutoff value was 17 days, with a sensitivity and specificity of 83.1% and 68.2%, respectively (AUC: 0.7707, 95% CI: 0.6695-0.8720, < 0.001).

Conclusion: Intraoperative hematoma volume could be a predictive value for CSDH recurrence.