IntroductionA chronic subdural hematoma (CSDH) is a well-known disease of intracranial hemorrhage in old people. The burr hole trephination is the usual treatment of CSDH with a good outcome and prognosis.Despite the simple treatment of CSDH, the recurrence rate of CSDH is not low. The recurrence rate of CSDH ranged between 10% and 33% in previous studies.26) Many studies have been reported on factors associated with the recurrence of CSDH; however, the results were inconsistent. The purpose of this study was to identify risk factors for the recurrence of CSDH. We hypothesized that some factors including age, sex, underlying disease, radiological images and surgical procedures affect the recurrence of CSDH. Series of 368 surgical patients were retrospectively evaluated and analyzed to support this hypothesis. Materials and Methods Patient selectionWe retrospectively evaluated 368 patients who underwent a surgery with CSDH. The patients visited the department of neurosurgery at Seoul National University Bundang Hospital between January 1993 and December 2013. Objective: Chronic subdural hematoma (CSDH) is a common form of extra axial hemorrhage in the elderly. A surgical procedures such as a burr hole trephination are used for the CSDH treatment. The recurrence rate of CSDH is reported to range from 2.3 to 33%. In the current study, we focused on the determination of risk factors associated with the recurrence of CSDH. Methods: We retrospectively reviewed 368 consecutive patients with CSDH treated by burr hole trephination. Univariate and multivariate analysis were performed to describe the relationships between clinical and radiological factors as well as the recurrence of CSDH. Results: Totally 31 (8.4%) patients experienced a recurrence of CSDH in our study. The male group (10.2%) had a higher recurrence rate than the female group (3.1%). Also patients with malignant neoplasm history showed a high recurrence rate (17.9%). The recurrence rate of single layer CSDH (13.1%) and isodensity CSDH (11.7%) was highly significant also. Conclusion: Sex, history of malignant neoplasm and the hematoma type on computed tomography were factors related with the recurrence of CSDH in our study. These findings may be supportive in the identification of patients at risk for a recurrence of CSDH. CLINICAL ARTICLE Korean

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