Gross total resection of pituitary adenomas after endoscopic vs. microscopic transsphenoidal surgery: a meta-analysis

Microscopic transsphenoidal surgery (mTSS) is a well-established method to address adenomas of the pituitary gland. Endoscopic transsphenoidal surgery (eTSS) has become a viable alternative, however. Advocates suggest that the greater illumination, panoramic visualization, and angled endoscopic views afforded by eTSS may allow for higher rates of gross total tumor resection (GTR). The aim of this meta-analysis was to determine the rate of GTR using mTSS and eTSS. A meta-analysis of the literature was conducted using PubMed, EMBASE, and Cochrane databases through July 2017 in accordance with PRISMA guidelines. Seventy case series that reported GTR rate in 8257 pituitary adenoma patients were identified. For all pituitary adenomas, eTSS (GTR=74.0%; I (2) = 92.1%) was associated with higher GTR as compared to mTSS (GTR=66.4%; I (2) = 84.0%) in a fixed-effect model (P-interaction < 0.01). For functioning pituitary adenomas (FPAs) (n = 1170 patients), there was no significant difference in GTR rate between eTSS (GTR=75.8%; I (2) = 63.9%) and mTSS (GTR=75.5%; I (2) = 79.0%); (P-interaction = 0.92). For nonfunctioning pituitary adenomas (NFPAs) (n = 2655 patients), eTSS (GTR=71.0%; I (2) = 86.4%) was associated with higher GTR as compared to mTSS (GTR=60.7%; I (2) = 87.5%) in a fixed-effect model (P-interaction < 0.01). None of the associations were significant in a random-effect model (all P-interaction > 0.05). No significant publication bias was identified for any of the outcomes. Among patients who were not randomly allocated to either approach, eTSS resulted in a higher rate of GTR as compared to mTSS for all patients and for NFPA patients alone, but only in a fixed-effect model. For FPA, however, eTSS did not seem to offer a significantly higher rate of GTR. These conclusions should be interpreted with caution because of the nature of the included non-comparative studies.