AUTHOR=Editorial Office Frontiers TITLE=Retraction: Laparoscopic vs. open pancreaticoduodenectomy after learning curve: A systematic review and meta-analysis of single-center studies JOURNAL=Frontiers in Surgery VOLUME=9 YEAR=2022 URL=https://www.frontiersin.org/journals/surgery/articles/10.3389/fsurg.2022.988654 DOI=10.3389/fsurg.2022.988654 ISSN=2296-875X