Evaluation of Pure Endoscopic Endonasal Approach in Management of Giant Pituitary Adenoma

Abstract

Background Giant pituitary adenoma represents one of the challenging tumor for neurosurgeons. Many microsurgical approaches in the past were used for its management. Recently and with evolution of the endoscopic equipment and instruments, extended endoscopic transsphenoidal approach become one of the preferable approaches for its surgical excision. Methods We prospectively document the clinical , surgical and follow up data for all patients presented with giant pituitary adenoma to Ain-Shams university hospital and Weill Cornell Medical College, Presbyterian hospital and were surgically treated with extended transsphenoidal approach from 2015 till 2019. Results Our group study formed of 44 patients with mean age 53.03 (range 14.7-82.4) and a male predominance (59%). The main presentation was visual problems in 75% followed by partial hypopituitarism in 31.81% while headache was in 13.64%. Only 4 patients had functioning adenoma (3 prolactinoma and 1 acromegaly). Average tumor volume was 26.95 ± 17.25 cm3, while the mean maximum tumor diameter was 4.73 cm (range 4.0-8.0 cm). Radiographic invasion was found in 97.73% to suprasellar cistern, 61.36% to the cavernous sinus and in 34% to the sphenoid sinus. GTR was achieved in 45.45% with Knosp score is the only significant predictor factor for resection rate (p = 0.04). Visual improvement achieved in 75.76%. 50% (2 patient) of the patients with functioning adenoma were cured. Complications included CSF leak in 3 patients, permanent DI in 4 patients and postoperative hematoma in 2 patients. Recurrence and progression rates without upfront radiation therapy were 5.00 % and 31.81% respectively after mean follow up period 57.90 months. Conclusions Extended endoscopic approaches for achieving maximum resection with minimal morbidity for giant pituitary adenoma are very effective. Lateral tumor extension with cavernous sinus invasion represents the limiting point in achieving gross total resection. Upfront radiation therapy for patients with residual adenoma can be avoided but regular follow up should be warranted.