Extracapsular en bloc resection in pituitary adenoma surgery

Purpose: A pituitary pseudocapsule often contains tumor tissue and should be removed for radical resection. It can be used as a surgical plane for more radical resection of the tumor in many cases of pituitary adenomas. We evaluated the advantages and disadvantages of extracapsular en bloc capsulectomy. Methods: From 1992 until 2011, 1,089 treated patients were grouped according to the resection technique: en bloc capsulectomy, fragmented capsulectomy, or piecemeal resection. Their surgical and endocrinological outcomes and complications were evaluated. Results: Extracapsular tumor resection was performed in 263 patients; en bloc capsulectomy in 94 patients and fragmented capsulectomy in 169, whereas piecemeal resection was performed in 826. Extracapsular resection was performed more frequently in prolactin- and thyroid-stimulating hormone-secreting tumors. Total resection was more frequently achieved in extracapsular resection and its chance was 100 % when tumors were removed in an en bloc fashion. For the functioning pituitary adenomas, endocrinological remission was achieved in all patients whose tumors were removed in an en bloc fashion and there was no recurrence. Postoperative cerebrospinal fluid (CSF) rhinorrhea developed in 4.2 and 2.7 % in the extracapsular resection group and the piecemeal resection groups, respectively. The chance of postoperative aggravation of pituitary function was not statistically different between groups. Conclusions: Extracapsular resection is critical for radical tumor resection and endocrinological remission. The removal of a pseudocapsule does not increase the risk of postoperative hypopituitarism nor postoperative CSF rhinorrhea.