Endoscopic Transnasal Removal of Giant Pituitary Adenomas: Long-Term Results

From January 1998 to January 2008, the senior authors (GBL, GF) operated on 447 pituitary adenomas by the transsphenoidal route with a purely endoscopic technique. Giant tumors (>3.5 cm on 1 axis) were present in 166 of these patients. We report the long-term results (minimum follow-up 36 months) in 146 of them. Ninety percent of the patients presented with a visual or visual field defect, and all of them had signs of hypopituitarism of variable degree or hormonal hypersecretion. One patient had a right-sided hemiparesis due to compression of the internal capsule. Fourteen percent of the tumors invaded at least 1 cavernous sinus, and 18% were recurrences.

All the operations were performed by a neurosurgeon and an ENT surgeon, using the 3- or 4-hand technique. Neuronavigation was used in all the recurrent tumors and in 6 cases of the extended approach. We had 1 surgical fatality, and the carotid artery was accidentally injured in 2 more cases. Two patients experienced the appearance of a visual field defect, and 85% of the visual deficits improved. Intraoperative CSF leaks appeared in 23% of the operations; 9 patients had to be reoperated on to close the fistula. Spinal drainage was never used. New substitution therapy was necessary in 4% of the patients, and diabetes insipidus (DI) appeared in 11% of the cases, but was permanent in only 3 patients. In 18% of cases pituitary insufficiency improved, but gonadal function never improved in this series. In 91% of the cases, the histological diagnosis was nonfunctioning pituitary adenoma. Mean hospital stay was 4 days.

Overall, MRI showed complete removal of the tumor was obtained in 74% of the cases and in 85% of the tumors not invading the cavernous sinus. None of the invasive tumors was completely removed. There has been no recurrence of completely removed tumors, but 3 patients have been reoperated on due to regrowth of residual tumor. Four invasive tumors have shown a malignant behavior (MIB 1 > 4), 2 patients have died after multiple transsphenoidal transcranial operations, radiotherapy, radiosurgery, and chemotherapy; 1 patient is waiting for her seventh operation, and 1 is currently being followed up after radiosurgery. Radiosurgery (or radiotherapy) has never been routinely employed to treat tumor remnants.

The endoscopic technique is safe and very well tolerated, and the results look similar or even better than the ones of most microsurgical series with the same patient population