Quantitative Assessment of Brain Expansion After Evacuation of Chronic Subdural Hematoma as a Predictor of Recurrence.

ABSTRACT

BACKGROUND: A lack of brain expansion is considered a risk factor for recurrence after evacuation of a chronic subdural hematoma (CSDH). To the best of our knowledge, no studies have reported on objective measurement of brain expansion after evacuation of a CSDH. METHODS: We performed a retrospective analysis of prospectively collected data of patients undergoing 2 burr hole evacuation of a CSDH. We measured the depth of the brain surface from the frontal burr hole dural opening after hematoma evacuation using a specially devised measuring tool. Other predictors analyzed for recurrence of hematoma were age, gender, a history of hypertension, the use of anticoagulant and/or antiplatelet agents, Glasgow coma scale score at presentation, unilateral or bilateral hematoma, computed tomography appearance, and hematoma thickness. RESULTS: Among 88 patients who underwent hematoma evacuation, 3 (3.4%) underwent surgery for recurrence. The significant factors associated with recurrence were the presence of bilateral hematoma (P = 0.001), hematoma width >2.3 cm (P = 0.04), gradation type of hematoma on the computed tomography scan (P = 0.03), and the depth of the brain after hematoma evacuation (P = 0.02). The brain expanded less in those with recurrence, with a mean depth of the brain of 18 ± 6 mm versus 7.27 ± 7.8 mm in those without recurrence. CONCLUSIONS: Evacuation of a CSDH through 2 burr holes, along with copious irrigation and bed rest for 3 days, resulted in a very low recurrence rate without the use of a drain. A lack of brain expansion might be a predictor of recurrence. To the best of our knowledge, this is the first study to quantitatively measure the depth of the brain at surgery in patients undergoing surgery for CSDH.