Risk factors for recurrence of chronic subdural hematoma after burr hole surgery: potential protective role of dexamethasone.

Objective: Chronic subdural hematomas (CSDHs) are often found in neurosurgery, and display a recurrence rate of up to 37%. This study aimed to determine potential risk factors contributing to unilateral CSDH recurrence, and evaluate the role of postoperative management with dexamethasone (DX) in reducing recurrence.

Methods: Between January 2010 and May 2015, a total of 242 consecutive patients with CSDH treated with burr-hole trephination were included in this study. Univariate and multivariate analyses were performed to determine risk factors potentially associated with the recurrence of CSDH. Then, patients at high risk were divided into DX and non-DX treatment groups, respectively. Chi-square test was used to assess the potential role of DX.

Results: CSDH recurrence was recorded in 39 patients (16.1%). Among various risk factors, advanced age (p = .01), preoperative midline displacement exceeding 10 mm (p < .001), and hematomas presenting with separated type (p = .03) were significantly associated with CSDH recurrence. Interestingly, patients who accepted therapy with DX had a lower rate of second drainage procedure (p = .017). In addition, DX effectively reduced disease recurrence in patients with the separated type of hematoma (p = .047), and seemed to be beneficial to those with advanced age and midline shift exceeding 10 mm, although statistical significance was not achieved.

Conclusion: These findings indicated that advanced age, midline displacement, and mixed density hematoma are independent factors for unilateral CSDH recurrence. When the above factors are detected in patients, additional DX administration should be recommended after operation.