Improvements in the Endoscopic Transsphenoidal Resection of Craniopharyngiomas: A Global Learning Curve

Background: Surgical management of craniopharyngiomas is nuanced and has varied in terms of the selected approach and aggressiveness of resection over time. In the past several decades, the endoscopic transsphenoidal approach has become commonly used for craniopharyngioma resection. There is a well characterized institutional ‘learning curve’ regarding endoscopic transsphenoidal approaches for craniopharyngiomas at specialized centers; however, the broader global learning curve remains to be characterized. Methods: Clinical outcome data following endoscopic transsphenoidal craniopharyngioma resection were obtained from a previously published meta-analysis, including data published during or after the year 1990. Additionally, the year of publication, the country where procedures were performed, and the human development index of the country at time of publication were abstracted. Meta-regressional analyses were used to determine the significance of year and human development index as a covariate of the logit event rate of clinical outcomes. Statistical analyses were performed using the Comprehensive Meta-Analysis with a priori significance set as P < 0.05. Results: A total of 100 studies (8230 patients) were examined, representing data from 19 countries. There was a significant increase in the achieved gross total resection rate (P = 0.0002) and a decrease in the achieved partial resection rate (P < 0.0001) across the time studied. Additionally, the rate of visual worsening (P = 0.025), postoperative cerebrospinal fluid leaks (P = 0.007), and development of meningitis (P = 0.032) decreased across time. Conclusions: This work suggests the existence of a global learning curve when examining clinical outcomes following endoscopic transsphenoidal craniopharyngioma resection. Globally, these findings highlight a general improvement in clinical outcomes across time.