Possible role of cyclooxygenase-2 in developing chronic subdural hematoma

Inflammatory cytokines are reportedly involved in the pathogenesis of chronic subdural hematomas (CSH), and the angiogenesis of hematomas has particularly been in focus. Cyclooxygenase-2 (COX-2) is an essential enzyme for the synthesis of prostaglandin E2 (PGE2). The COX-2-PGE2 pathway has been shown to influence angiogenic factors such as vascular endothelial growth factor (VEGF). We investigated the association of COX-2 expression in the dura mater and outer membrane with the pathogenesis of CSH, and suggested a treatment strategy on the basis of this association. Hematoma fluid and serum samples obtained from 37 patients, and samples of the dura mater and outer CSH membrane obtained from 13 patients during the operation were examined in this study. The concentrations of PGE2 in relation to COX-2 in the hematoma fluid were significantly higher than those in the serum. Immunohistochemical analyses revealed COX-2-positive cells in the outer membrane of CSHs. There was a linear and significant relationship between PGE2 concentration in hematoma fluid and the interval from trauma to initial surgery. COX-2 may play a crucial role during the development of CSHs. Our study might lead to the development of anti-COX-2 treatment options that aim to minimize repeat surgery and choose medical therapy by reducing CSH morbidity and recurrence rate in patients with CSH.