Endoscopic endonasal approach to pituitary adenomas: Impact on adenohypophyseal function. Study of 231 cases.

Purpose: To identify presurgical and surgical factors associated with the development of hypopituitarism and its recovery after endoscopic endonasal transsphenoidal (EET) resection of pituitary adenomas (PAs).

Methods: Retrospective study of patients with PAs operated by the same neurosurgeon through an EET approach in two Spanish tertiary hospitals in ten years.

Results: 242 pituitary surgeries performed in 231 patients were analyzed. In the 154 surgeries performed in 146 patients with non-functioning PAs (NFPAs), 46.8% (n=72) presented presurgical hypopituitarism. After PAs resection, 41 of these (56.9%) normalized pituitary function and 11 of 82 patients with preoperative normal function (13.4%) developed new pituitary deficits. Patients with preoperative visual impairment (OR=3.9, p=0.046) and operated in the first four years of the neurosurgeon's learning curve (OR=5.7, p=0.016) presented a higher risk of developing postoperative hypopituitarism. Of the 88 surgeries in 85 patients with functioning PAs (FPAs), 23.9% presented presurgical hypopituitarism, and 47.6% of those recovered after surgery. 9% of the cases with preoperative normal function developed new pituitary deficit/s. Diabetic patients presented a higher risk of persistence of hypopituitarism (OR=10.5, p=0.024). Patients with presurgical visual impairment (OR=30.0, p=0.010) and PAs>3cm (OR=14.0, p=0.027) had higher risk of developing new pituitary deficits.

Conclusion: Approximately 50% of patients with PAs and preoperative hypopituitarism recover pituitary function after EET surgery. 10% of patients with normal function develop new deficits. Patients with NFPAs with visual involvement and operated in the first four years of neurosurgeon's learning curve, and FPAs patients with presurgical visual impairment and tumor size>3cm have a higher risk of postoperative hypopituitarism.