Efficacy of arachnoid-plasty on chronic subdural hematoma following surgical clipping of unruptured intracranial aneurysms

Abstract Background We aimed to elucidate the effects of arachnoid plasty (ARP) on chronic subdural hematoma (CSDH) occurrence following clipping surgery. Methods In total 217 patients (ARP, n = 97; non-ARP, n = 120) who had undergone unruptured intracranial aneurysm (UIA) surgical clipping via the pterional approach were retrospectively assessed. Predisposing factors for CSDH development following the surgery were investigated. Thickness and volume of the subdural fluid collection (SDFC) were measured to determine whether ARP affects postoperative SDFC. Results The occurrence of postoperative CSDH was higher in patients without ARP compared to those with ARP (12.5 vs. 3.1%, p = 0.01). In multivariate analyses, having an SDFC volume on post-operative day (POD) 8 ≥ 15 ml, (OR = 15.113, range = 3.159-72.290), and male sex (OR = 4.274, range = 1.291-14.148) were identified as independent predictive factors. Having had ARP (OR = 0.228, range = 0.056-0.927) was, as an independent variable, negatively correlated with the occurrence of CSDH (p < 0.05). Moreover, SDFC volume on POD 8 ≥ 15 ml were significantly less common in the ARP group compared to the non-ARP group (p = 0.03). Conclusions Patients who underwent ARPs developed CSDHs following UIA clipping surgery less. The factors that predicted the development of CSDH included the male gender, SDFC volume on POD 8, and ARP. In addition, the ARP patients had less SDFC volumes (