Quantitative assessment of post-operative recurrence of chronic subdural haematoma using mean haematoma density

Purpose: The purpose of this study was to establish a quantitative method with which to assess the post-operative recurrence of chronic subdural haematoma (CSDH). Methods: CT scans were reviewed from 44 consecutive patients with CSDHs who underwent burr hole drainage between July 2008 and January 2012. The area of the haematoma was quantified according to the mean haematoma density (MHD) using computer-based image analysis of pre-operative brain CT scans. MHD as well as other variables of patients with and without post-operative recurrences was statistically compared. Results: Post-operative recurrence was noted in six of the 44 patients that underwent surgical procedures. Among these variables, high MHD, separated type and bilateral and skull base involvement of CSDHs were shown to be significantly related to post-operative recurrence (p < 0.05). Controlling for separated type in logistic regression analysis revealed the OR of MHD as statistically significant indicators with a p value of less than 0.05 (OR = 1.243; 95% CI = 1.003-1.54). Conclusion: This study provides statistical proof that MHD is a significant, independent, prognostic factor for the post-operative recurrence of CSDH. As such, consideration of MHD could aid in the prediction of post-operative prognosis of CSDHs.