Variation of Ventricular Size after Surgical Treatment of Chronic Subdural Hematoma

BACKGROUND: Surgical removal is the treatment of choice for chronic subdural hematoma (CSDH). Despite clinical improvement after surgery, computed tomography (CT) scan control often showed residual collection, which may discuss the possibility of failed surgery. The aim of this study is the assessment of ventricular size before and after surgery and to study its relation with residual hematoma. METHODS: In this prospective study (2013-2016), 63 patients who had burr-hole drainage of CSDH were sequentially allocated to either two groups; Group 1 with CT scan control under the 3(rd) day of surgery and Group 2 with delayed CT scan control (from 4(th) to 7(th) day). Linear measure of ventricular size was assessed by Evans’ index. We reviewed and analyzed the data between both groups. RESULTS: There were 33 patients in Group 1 and 30 patients in Group 2. Preoperatively, the average thickness of hematoma was 20.5 mm in Group 1 versus 19.9 mm in Group 2 (P = 0.67); the mean midline shift was 8.5 mm in each group; Evans’ index was 26.7% in Group 1 and 27% in Group 2 (P = 0.7). Postoperatively, the mean thickness of the residual hematoma was 7.7 mm in Group 1 and 8.4 mm in Group 2 (P = 0.57); the mean midline shift was 3.3 mm in Group 1 and 1.9 mm in Group 2 (P = 0.08); Evan's index was 28.5% in Group 1 and 32.1% in Group 2 (P = 0.002). CONCLUSION: The adoption of Evans’ index, for assessing the variation of ventricular size after surgery, by neurosurgeons appears to be a good and simple method for evaluation and following the success of surgical removal of CSDH, despite the observation of some residual collection in early CT scan control.