Surgical treatment of chronic subdural hematoma based on intrahematomal membrane structure on MRI

Background. To determine the optimal surgical management of chronic subdura l hematoma (CSDH). we assessed which operative procedure, burr holes or sma ll craniotomy, was more effective on 49 consecutive patients. Method. We re trospectively classified all cases into two groups according to the intrahe matomal membrane structure of CSDH on T-2*-weightcd magnetic resonance (MR) imaging. The first group, labeled type B, included hematomas which had no intrahematomal membrane and/or were monolayer multilobule. The second group . labeled type C. consisted of hematomas which were divided into multiple l ayers by the intrahematomal membrane. Findings. The outcome of type C patie nts treated with burr holes was significantly inferior to that of those who underwent a small craniotomy in terms of the relative outcome of neurologi cal grading, reoperation ratio, and postoperative hospital stay(p < 0.05). Type C hematomas treated with burr holes also had inferior outcome compared with a small craniotomy in terms of the duration of hematoma until disappe arance on postoperative CT (p < 0.05). Interpretation. We concluded that a considerable number of cases appeared to need craniotomy and resection of i ntrahematomal membrane for complete recovery in CSDH, and that T-2*-weightr d MR imaging could be used as a basis for selecting the operative procedure for CSDH.