Evaluation of Outcome after Endoscopic Endonasal Surgery for Large and Giant Pituitary Macroadenomas

Objective: The endoscopic endonasal approach to pituitary neoplasms has shown similar or superior efficacy compared with the microscopic approach. However, outcomes and complication rates with larger macroadenomas are not as well documented. This study specifically addresses the efficacy and outcome of the endoscopic endonasal approach for large and giant pituitary adenomas.

Methods: Thirty patients with large or giant pituitary macroadenomas (tumors > 2.5 cm in greatest diameter) underwent endoscopic endonasal resection. Tumors were divided among 2.5 cm, 3.4 cm, and those > 3.5 cm. Outcomes were assessed using formal neuroophthalmological examination, endocrine status, and patient neurological outcome. Statistical analyses of multiple variables (age, sex, time from diagnosis to surgery, extent of visual or endocrine abnormality prior to treatment, tumor size, tumor location, extent of resection, and recurrent tumors) were addressed for correlation to visual, endocrine, and neurological outcomes.

Results: Seven patients had prior transsphenoidal surgery at other institutions, and 19 patients (those with a tumor greater than or equal to 3 cm) had undergone expanded endoscopic exposure and/or reconstruction with nasoseptal flap. Gross total resection of the macroadenomas was achieved in 19 of 30 patients (63%) based on postoperative MRI. Of the 11 patients with residual tumor, 8 of these (73%) were only in the cavernous sinus. Fifteen of 18 patients (83%) with visual deficit prior to surgery had documented improvement of visual field and acuity. Six patients (20%) needed new postoperative hormone replacement therapy or an increase in preoperative treatment, among which 2 had new diabetes insipidus. Time from diagnosis to surgery, preoperative visual deficit, and tumor size were not considered as significant predictors of visual outcome. Older age, longer time from diagnosis to surgery, smaller tumor size, and higher preoperative prolactin levels were more associated with good endocrine outcome although not statistically significant. Three patients presented with a postoperative CSF leak, which resolved with lumbar drainage. The most common nonvisual, non-hormonal postoperative complaint was sinusitis, occurring in 20% of patients. The mean follow-up period was 7 months. There were no cases of new cranial nerve deficits, new neurologic deficit, or mortality.

Conclusions: Endoscopic endonasal resection of large and giant pituitary macroadenomas, combined with expanded approaches when needed is safe and efficient. Postoperative complications are very low. Surgical efficacy of this approach makes the endoscopic endonasal technique an extremely appealing option in this subset of patients.