Chronic subdural hematoma(CDH) is collection of encapsulated ligified hematoma in subdural space and familiar with neurosurgens. 50 patients of CDH were treated using burr holes and closed-system drainage. The study is a retrospective clinical analysis and reviewed of the surgical method.

Between 1995 and 2001, 50 patients with CDH had surgical treatments, using burr holes and closed-system drainage technique at the department of neurosurgery, Ewha Uninversity Medical Center, Mok-Dong hospital. Mean age was 61 years with a range 35-82 years. The male/female ratio is 41/9. Diagnosis of CDH was confirmed by CT scans. The author divided into 2 groups ; traumatic group and atraumatic group. Retrospectively the author analysed the clinical data regarding age group, sex ratiso, etiology, neurologic grade at admission, post-operative outcomes and outcomes according to neurologic grade at admission. These clinical data compared the traumatic group with atraumatic group.

The number of patients were 27 in traumatic group and 23 in atraumatic groups. The mean age in traumatic and atraumatic groups was 60 years respectively. These lesions generally occur in elderly with the average 61 years. The male/female ratio 21/6 in traumatic group and 20/3 in atraumatic group. Generally it was predominent in male patients. The causes in atraumatic group were hypertension(2 patients), CVA(3 patients) and the others remain unknown. The neurologic grade at admission ; 0 grade 26(male/female=21/5, 1 grade) 7(m/f=6/1), 2 grade 14(m/f=11/3). The outcome scale according to glasgow scale ; 5 scale 31(m/f=24/7), 4 scale 15(m/f=13/2) and 3 scale 4(m/f=4/0). The outcome scale according to neurologic grade at admission was that the more neurologic grade is good, the more outcome is better.

The burr holed and closed system drainage technique is simple, mininal risk, and results in good recovery with short days of admision. This technique is considered as first choice for the evacuation of hematoma of CDH.