Factors influencing the outcome of microsurgical transsphenoidal surgery for pituitary adenomas: A study on 184 patients

OBJECTIVE: Evaluation of factors influencing the outcome of microsurgical transsphenoidal surgery in patients harbouring pituitary adenomas as well as of the efficacy and safety of this procedure. DESIGN: A total of 184 consecutive patients with pituitary adenomas, undergoing microsurgical transsphenoidal resection of their lesions from March 2004 to June 2011, were prospectively studied. Extent of tumour resection and disease remission were defined according to recently established radiological and hormonal consensus criteria. RESULTS: The study included 97 nonfunctioning and 87 functioning adenomas. A gross-total removal, as documented on postoperative imaging, was achieved in 67.4% of all patients. Residual tumour after surgery was detected in 37.1% of patients with nonfunctioning adenomas. The remission rates for patients with functioning adenomas, as documented by the last endocrinological evaluation, were 54.9% for growth hormone-secreting, 69.5% for adrenocorticotropin hormone-secreting, 72.7% for prolactin-secreting and 100% for thyroid-stimulating hormone-secreting, with two recurrences in patients with Cushing's disease. Multivariate analysis showed that factors influencing surgical outcome were cavernous sinus invasion, large tumour diameter (>= 25 mm) and reoperation for the nonfunctioning adenomas, and cavernous sinus invasion as well as large tumour diameter (>= 25 mm) for the functioning adenomas. In the latter cohort, predictors for endocrinological remission were maximum tumour diameter (<= 20 mm) and reoperation. Postoperative complications were present in 3.3% of the cases. One patient developed epistaxis, two hemorrhage at the surgical field, one postoperative rhinorrhea, one postoperative permanent diabetes insipidus and one postoperative panhypopituitarism. CONCLUSIONS: Microsurgical transsphenoidal surgery is an effective and safe treatment in all patients with pituitary adenomas, except for prolactinomas responsive to medical therapy.