Speculum-Assisted Endoscopic Transnasal Transsphenoidal Approach to the Skull Base: A Technical Note with Case Illustration

Abstract

Speculum utility and design in endonasal skull base surgery has undergone persistent refinement over the past 20 years. Speculums are a mainstay of microscopic approaches to the skull base, while their use in endoscopic approaches is non-routine. To illustrate the utility of a speculum-assisted transnasal transsphenoidal endoscopic operative approach to the skull base in the resection of a suprasellar mass. A 53-year-old male presented to the emergency department with three months of headache and progressive peripheral vision loss. Magnetic resonance imaging confirmed a suprasellar mass measuring 17.6 mm × 29.5 mm × 17.7 mm with significant mass effect on the optic chiasm. Resection of the sellar mass was performed using a speculum-assisted transnasal transsphenoidal endoscopic approach. Following middle turbinate mobilization, an 8 mm Hardy endonasal speculum was inserted into a single nostril. Optimal positioning was obtained with the tip of the speculum just rostral to the sphenoid ostium. The speculum remained in position for the remainder of the case. The sphenoid sinus and sellar walls were visualized and instrumentation was freely maneuvered through the dilated operative corridor. The speculum shielded underlying nasal mucosa, thereby preventing condensation buildup on the lens of the endoscope, minimizing inadvertent mucosal trauma, and preventing blood from disrupting the operative field. After resection, the nasal passage remained atraumatic. Six hours after surgery the patient reported near complete resolution of visual deficits and no post-operative nasal pain. The use of a dilated Hardy speculum for the entirety of an endoscopic transnasal procedure provided a generous operative corridor for ample instrument maneuverability and anatomical visualization. This approach also allows for the protection of the nasal mucosa and minimizes bleeding. Additional studies are needed to compare this modified operative technique with traditional endoscopic approaches to the skull base.