Techniques and challenges of the expanded endoscopic endonasal sellar and parasellar approaches to invasive pituitary tumors

Superb knowledge of surgical anatomy and nuances to remove the natural barriers preventing full access to the paramedian skull base determines the ease of using the expanded sellar/parasellar approaches as the main gateway for all the parasagittal modules during endoscopic endonasal access (EEA) to pituitary tumors with cavernous sinus (CS) invasion. Throughout stepwise-cadaveric dissections and pertinent intraoperative analysis, we describe surgical pearls and pitfalls of the parasellar-EEA with special references to the utility of various lines/classifications on neuroimaging correlated with strategies to enhance surgical safety and tumor resection. EEA to invasive parasellar pathologies needs to address strict bleeding control and displacement of neurovascular structures inside the CS, posing a chance for neurologic morbidities/ICA injury. Meticulous utilization of operative landmarks and strategies can help avoid and mitigate surgical complications.