Introduction to Expanded Endonasal Approach of the Pituitary Fossa: The Role of Rhinologic Surgeon

ABSTRACT

The expanded endonasal approach (EEA) to the ventral skull base provides endoscopic access from the frontal sinus to the second cervical vertebra. Potential advantages of the EEA include not only improved cosmesis but more importantly, the potential for reduced neurovascular manipulation. EEA is based on the principle of extracapsular dissection with full visualization of important neurovascular structures. There are significant risks of neural and vascular injury associated with EEA, and the reconstruction of dural defects is challenging. Experienced teams including rhinologists and neurosurgeons are needed for successful implementation of EEA. The surgical team must have adequate endoscopic skills to achieve hemostasis and address vascular emergencies. Advantages of having a skilled second surgeon to provide endoscopic visualization include dynamic adjustments of the endoscope to ensure the best view and avoid contact interference of instruments, second surgical opinions in complex anatomical areas, and maintenance of endoscopic views in cases of crisis such as vascular injury. Complications of the EEA such as neurovascular injury, cerebrospinal fluid leaks and infection are the same as those of open approaches. With the advent of the nasoseptal flap, problematic cases involving huge bony defects subsequent to the resection of skull base tumors have been greatly resolved.