ENDOSCOPIC ENDONASAL PITUITARY TRANSPOSITION FOR A TRANSDORSUM SELLAE APPROACH TO THE INTERPEDUNCULAR CISTERN

Objective The interpeduncular cistern, including the retroinfundibular area, is one of the most challenging regions to approach surgically. The pituitary gland and the infundibulum guard the region when an endonasal route is undertaken. Superior transposition of the pituitary gland and infundibulum is described as a functional means to access this complex region through a fully endoscopic, completely transnasal route. Methods Ten consecutive patients in whom a pituitary transposition was performed during an expanded endonasal approach at the University of Pittsburgh Medical Center for resection of retroinfundibular lesions were reviewed. The series consisted of seven men and three women with a mean age of 44.4 years. Pathology consisted of four craniopharyngiomas, four chordomas, and two petroclival meningiomas. Results Five patients (50%) underwent total resection of the tumor, three patients (30%) underwent near total resection ( > 95% removal), and two patients (20%) had partial resection of petroclival meningiomas with the goal of optic apparatus decompression. All four patients with visual deficits recovered their vision completely. There was no neurological deterioration. Eight patients had normal pituitary function preoperatively, seven of whom (87.5%) had confirmed function preservation postoperatively, with one of these patients experiencing transient diabetes insipidus. The remaining patient with a hypothalamic craniopharyngioma underwent complete resection with obligatory panhypopituitarism and diabetes insipidus. Conclusion Endoscopic endonasal transposition of the pituitary gland and its stalk can provide a valuable corridor to the retroinfundibular space and interpeduncular cistern with pituitary function preservation in the majority of patients. This approach should only be pursued once significant experience with endoscopic endonasal approaches has been acquired.