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 T2*-weighted 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. re-operation 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 T2*-weighted MR imaging could be used as a basis for selecting the operative procedure for CSDH.