Postoperative recurrence rates in chronic subdural hematoma patients who underwent burr-hole trephination with parietal or occipital drainage compared to frontal drainage

Objective We conducted a retrospective study involving 348 patients with suspected chronic subdural hematoma who underwent burr-hole trephination. The primary objective was to examine the relationship between the postoperative subdural drainage catheter's position and the recurrence rate. Methods In a retrospective study conducted at Ewha Womans University Mokdong Hospital between September 2020 and August 2023, patients diagnosed with chronic subdural hematoma underwent surgical intervention. We defined the recurrence of chronic subdural hematoma as an increase in the volume of subdural fluid on the treated side compared to the volume measured just before the computed tomography scan was performed. Results The recurrence rates were not significantly different between these 2 groups (20.3% vs. 20.5%, P=0.594). Additionally, there was no significant difference in mean age (74.9 vs. 75.8 years, P=0.733), male-to-female ratio (3.29 vs. 3.25, P=0.478), or maximum depth (13.5 mm vs. 12.7 mm, P=0.323) between the 2 groups. Conclusion There was no significant difference in the recurrence rates between the 2 groups. This suggests that the location of the burr-hole trephination and the subdural catheter tip location might have had no significant impact on patients’ prognosis. In order to reduce the recurrence rate of chronic subdural hematoma, making efforts to minimize other factors like subdural air collection is important. Keywords: Chronic subdural hematoma; Catheter tip location; Recurrence rate