Factors Affecting Brain Re-expansion after Simple Burr Hole Drainage in Chronic Subdural Hematoma

ABSTRACT

Delayed brain re-expansion is one of the most frequent problems on the chronic subdural hematoma. The aim of this study is to determine the factors affecting brain re-expansion. The study consists of 76 patients with the chronic subdural hematoma treated primarily by simple burr-hole drainage from January 1992 to December 1996. Clinical records and radiologic studies were reviewed retrospectively. The age distribution ranged from 22 to 82 years(mean 64 years), the male-to-female ratio was 1.81(4927). At the 2nd, 4th, 6th and 12th week after surgery, the follow-up study was performed with computed tomography or magnetic resonance image. Complete brain reexpansion was defined as that the subdural space was 5mm or less without midline shift on computed tomography or magnetic resonance image. The factors interfering the brain re-expansion are as follows; d age, low Glasgow Coma Scale(GCS) score on admission, history of chronic alcohol consumption, hypodense hematoma on computed tomography, bilateral hematoma, disappearance of intraoperative brain pulsation, and long duration after trauma. The results of this study may be helpful to predict the brain re-expansion after simple burr-hole drainage. If the complete brain re-expansion is not observed immediately, it should be waited for 6 weeks to conduct the follow-up study. Patient's position and sufficient hydration are important for brain expansion. Further investigations on other factors related to promotion of the brain re-expansion should be followed.