A Benchmark for Preservation of Normal Pituitary Function After Endoscopic Transsphenoidal Surgery for Pituitary Macroadenomas

INTRODUCTION: We report a contemporary consecutive series of 80 patients operated on for benign pituitary macroadenomas, followed endocrinologically for at least 3 months postoperatively. These patients were systematically evaluated preoperatively by high-resolution magnetic resonance imaging designed to detect the position of normal gland relative to the lesion. The rate of preservation of normal pituitary was critically analyzed using this strategy combined with endoscopic transsphenoidal resection. METHODS: This is a retrospective review of 46 women and 34 men with mean postoperative follow-up of 14 months (range, 3-30 months). The lesions encountered consisted of 80 pituitary macroadenomas (55 nonfunctioning, 18 acromegaly, 5 prolactinoma, 1 Cushing, one thyroid-stimulating hormone). Pituitary endocrine status was determined preoperatively and at most recent follow-up, and categorized as normal or impaired, based on laboratory studies showing new hormone deficiency or the need for pituitary hormone replacement therapy. RESULTS: Fifty-three patients (66.3%) had normal endocrine function preoperatively; 3 (5.7%) had loss of function postoperatively (1 transient). Twenty-seven patients (33.8%) had impaired function preoperatively; postoperatively 20 (74.1%) were unchanged, and 5 (18.5%) were worse; 2 (7.4%) recovered lost pituitary function. Of 80 patients undergoing resection, 5 (6.3%) had worsened pituitary function postoperatively. Patients with recurrent lesions (n = 5, 6.3%) and those presenting with pituitary tumor apoplexy (n = 5, 6.3%) were more likely to become further impaired. Other endocrine sequelae included 2 patients with permanent postoperative diabetes insipidus and 3 with transient symptomatic syndrome of inappropriate secretion of antidiuretic hormone. CONCLUSIONS: The preservation and restoration of hormonal function are essential to assessing the outcome of surgery and to the patient's quality of life. Careful analysis of the anatomy of the pituitary lesions and their effect on the anatomy and physiology of the pituitary gland are crucial to success and allow modern technological advances to provide fewer complications of therapy and improved outcomes for our patients. The benchmarks provided in this article are a stimulus for even better results in the future as we take advantage of technical and conceptual advances and the benefits of multidisciplinary collaboration.