Surgical Decision-Making in a Parasagittal Meningioma with Chronic Anterior Superior Sagittal Sinus Occlusion: An Illustrative Case Report

<title>Abstract</title> <p> Background: Parasagittal meningiomas involving the superior sagittal sinus (SSS) remain surgically challenging because operative strategy is determined not only by the anatomical extent of sinus involvement but also by the functional significance of the affected venous segment. The need for sinus reconstruction remains controversial. ^[1-5] Case Presentation: A 50-year-old woman presented with a right frontal parasagittal meningioma. Contrast-enhanced magnetic resonance imaging (MRI) demonstrated a dural-based lesion adjacent to the anterior third of the SSS (Fig.1). Magnetic resonance venography (MRV) showed complete absence of a flow-related signal within the involved sinus segment and prominent collateral cortical venous channels (Fig.2). Computed tomography (CT) demonstrated adjacent focal hyperostosis (Fig. 3). A right parasagittal craniotomy was performed. Intraoperatively, the involved sinus segment was fibrotic, collapsed, and devoid of a functional lumen. Multiple collateral cortical venous pathways were identified and preserved. Progressive surgical assessment confirmed that the occluded sinus segment was no longer participating in cerebral venous drainage. Gross total tumor resection (Simpson grade II) was achieved without sinus reconstruction. Postoperative imaging showed no hemorrhage, venous infarction, or residual tumor (Figs.4 and Figs.5). Histopathology confirmed transitional meningioma, CNS WHO grade 2 (Fig.6). Conclusions: Chronic occlusion of the anterior SSS may evolve into functional exclusion through collateral venous adaptation. In such cases, preoperative imaging, intraoperative functional assessment, and preservation of collateral venous drainage together may permit safe gross total resection without routine sinus reconstruction. </p>