Endoscopic Endonasal Surgery in Recurrent and Residual Pituitary Adenomas After Microscopic Resection

BACKGROUND: Despite the increasing interest in endoscopic techniques for pituitary surgery, little has been published on the endoscopic approach for recurrent and/or residual pituitary adenomas. We report the outcome of purely endoscopic endonasal surgery for a series of recurrent and/or residual pituitary tumors after a previous microscopic resection. METHODS: We reviewed all of the patients in our institution who underwent endoscopic resection for recurrent and/or residual pituitary tumors after previous microscopic resection. All patients had clinical and magnetic resonance imaging follow-up of at least 3 months postoperatively. Careful attention was given to the operative reports documenting the degree of previous microscopic exposure. Our results were compared with published reports of surgery for recurrent and residual pituitary tumors. RESULTS: Thirty-nine patients met our inclusion criteria. The mean follow-up was 21 months. Tumors were comprised of 19 nonfunctional, 10 adrenocorticotropic hormone, 9 growth hormone, and 1 prolactin-secreting adenoma. The endoscopic procedure revealed limited previous exposure of the sphenoidal and sellar structures in 30 cases (76%). Sphenoidotomy and sellar opening, in terms of working area and angle of view, were significantly restricted in 64% and 61% of the cases, respectively. Gross total removal was achieved in 46% of cases. Seventeen patients had frank cavernous sinus invasion. CONCLUSIONS: The restricted exposure of sphenoidal and sellar structures by the microscopic approach may be a contributing factor to incomplete tumor resection. The results observed in this setting make the endoscopic technique a valid option in recurrent and residual pituitary adenomas treated initially by microscopic surgery.