Use of twist-drill craniostomy with drain in evacuation of chronic subdural hematomas: independent predictors of recurrence.

BACKGROUND: Recurrence rates after chronic subdural hematoma (CSDH) evacuation with any of actual techniques [twist-drill craniostomy (TDC), burr-hole craniostomy, craniotomy] range from 5% to 30%. Use of drain has improved recurrence rates when used with burr-hole craniostomy. Now, we analyze predictors of recurrence of TDC with drain. METHOD: Three hundred twelve consecutive patients with CSDH have been studied in a retrospective study. Operative technique in all patients consisted in TDC with drain. Data recorded included any associated comorbidity. Radiologic measures of the CSDH before and after the procedure were studied. Clinical evaluation included Modified Rankin Scale, Glasgow Coma Scale (GCS), and neurological deficits. Two groups were compared: recurrence group and nonrecurrence group. Follow-up was for at least 1 year. RESULTS: Twelve percent experienced recurrence. Preoperative CSDH width, preoperative midline shift, postoperative midline width, postoperative CSDH width, and residual CSDH 1 month later were significantly associated with CSDH recurrence. The logistic regression model for the multivariate analysis revealed that postoperative midline shift and postoperative neurological deficit were significantly associated with CSDH recurrence. The duration of treatment with dexamethasone was found not to be related with recurrence. Mortality before hospital discharge was 1%. Hospital stay was 2.5 days. CONCLUSIONS: TDC with drain has similar results in recurrence rates, morbidity, mortality, and outcome as other techniques as burr-hole craniostomy with drain. Preoperative and postoperative hematoma width and midline shift are independent predictors of recurrence. Brain re-expansion and time of drain maintenance are important factors related with recurrence of CSDH. Future CSDH reservoirs must avoid negative pressure and sudden pressure changes inside the whole closed drain system.