Pseudocapsular Resection Technique for Large Pituitary Macroadenomas

Introduction: Pseudocapsular resection entails first defining the compressed reticular layer surrounding pituitary microadenomas, and then dissecting around this layer for en bloc resection. In Cushing’s disease the technique has been associated with remission rates exceeding 90%. We developed a modified pseudocapsular technique that, among other refinements, included central tumor debulking, if needed, to allow an en bloc resection of pituitary macroadenomas. Methods: Consecutive series from January-September 2012 of patients undergoing dual-surgeon endoscopic, endonasal surgery for pituitary macroadenomas. (n = 33; age, 53 ± 18 years; nonfunctional, 23; prolactinoma, 6; acromegaly, 3; Nelson’s syndrome, 1). We analyzed the technical results as follows: (1) Complete en bloc resection without central debulking (n = 5); (2) complete en bloc resection with central debulking (n = 16); (3) probable complete resection, but unable to utilize en bloc resection (n = 5); and (4) incomplete resection (n = 7). Results: We were able to achieve en bloc resection in the majority (64%) of macroadenomas up to 4.2 cm in size. Complete en bloc resection without debulking occurred with smaller tumors (13 ± 3; range, 10-16 mm) compared with debulking method (26 ± 8; range, 16-42 mm). Among the en bloc resections, endocrinologic deterioration was limited to one patient developing permanent diabetes insipidus. Reasons for inability to achieve pseudocapsule resection included cavernous sinus invasion, inability to identify/maintain a pseudocapsule, and reoperation (n = 3). Conclusion: Pseudocapsular dissection (video technique will be presented) is possible in the majority of pituitary macroadenomas with good outcomes. The technique should be more widely considered for macroadenomas as it is feasible and theoretically may lead to higher cure rates.