Twist-Drill Evacuation of Chronic Subdural Hematoma: Clinical Correlation with Postoperative Radiological Findings

Chronic subdural hematoma (CSDH) is a frequent intracranial hemorrhage with generally favorable outcomes but often requires surgery. Twist-drill evacuation is a minimally invasive option providing gradual decompression and reducing pneumocephalus, but residual subdural collections commonly persist postoperatively, creating uncertainty about recurrence and reintervention thresholds. The role of routine postsurgical imaging remains debated.

We conducted a prospective observational study of consecutive adults undergoing standardized twist-drill evacuation for symptomatic CSDH. Clinical and radiological assessments were performed preoperatively and at 1 week, 1, 3, and 6 months. Outcomes included Glasgow Coma Scale, Markwalder grade, health-related quality of life, hematoma volume, maximal thickness, midline shift, and weekly shrinkage rate.

Twenty-six patients were included with complete 6-month follow-up. At 1 week, 81% of patients were asymptomatic and 15% showed clinical improvement, with clinical status tending toward normalization by 1 month. Radiological resolution lagged behind clinical recovery. Despite clinical normalization, residual hematoma persisted in 65% at 3 months and 15% at 6 months. Imaging parameters did not predict clinical success, whereas greater 1-week volume reduction predicted larger subsequent radiological resorption (P ≤ 0.015). One patient (3.9%) required reoperation for absent early improvement.

Twist-drill evacuation of CSDH is associated with earlier clinical improvement than radiological normalization. An abnormal early postoperative computed tomography should not be considered an indicator of recurrence and should not drive revision surgery based on imaging alone, unless accompanied by clinical deterioration or absent improvement without hematoma size reduction.