Extracapsular Resection of Pituitary Adenomas: A Systematic Review

There is considerable variation in the surgical techniques for transsphenoidal excision of pituitary tumors. Recently, an extracapsular method has been developed that involves using the tumor pseudocapsule as a dissection plane to increase the extent of resection. This review assessed the outcomes of this new approach as compared with standard transsphenoidal surgery. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE/PubMed, the US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP; apps.who.int/trialsearch), and LILACS databases for relevant literature and checked reference lists of relevant articles. Randomized controlled trials and prospective and retrospective cohort studies comparing extracapsular and intracapsular resection of pituitary tumors were included in the review. Five cohort studies with 1,588 participants were included. Extracapsular resection was associated with a higher likelihood of complete excision (relative risk [RR] 1.31, 95% confidence interval [CI] 1.01-1.70, p  = 0.04) and endocrinologic remission (RR 1.26, 95% CI 1.03-1.54, p  = 0.02). Because there was a significant risk of bias and substantial heterogeneity, the estimates of effect may not be robust. In patients with pituitary adenomas undergoing transsphenoidal excision, extracapsular resection may be associated with higher rates of complete excision and endocrinologic remission, but the evidence is not strong. Hence, randomized controlled trials to determine the magnitude of benefit and identify an improvement in progression-free or overall survival are warranted.