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

Background. To determine the optimal surgical management of chronic subdural hematoma (CSDH). we assessed which operative procedure, burr holes or small craniotomy, was more effective on 49 consecutive patients. Method. We retrospectively classified all cases into two groups according to the intrahematomal 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 layers by the intrahematomal membrane. Findings. The outcome of type C patients treated with burr holes was significantly inferior to that of those who underwent a small craniotomy in terms of the relative outcome of neurological 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 disappearance on postoperative CT (p < 0.05). Interpretation. We concluded that a considerable number of cases appeared to need craniotomy and resection of intrahematomal membrane for complete recovery in CSDH, and that T-2*-weightrd MR imaging could be used as a basis for selecting the operative procedure for CSDH.