Search methodology
PubMed, EMBASE, The Cochrane Library, CNKI and VIP were comprehensively searched up to December 2020. The search terms were a combination of medical subject headings (MeSH) terms and the following free words: Mitral Regurgitation, Mitral Valve Replacement, Mitral Valve Repair, Endoscopes, Thoracoscopes, Robot-assisted, Robotic Surgical Procedures, Minimally Invasive Surgical Procedures, Thoracotomy. In addition, we manually searched for other potential and relevant references. There were no limitations in the language of all publications. Take PubMed as an example, its strategy is as follows:
#1 Mitral regurgitation [Mesh]
#2 Mitral valve replacement [Title/Abstract] OR Mitral valve repair [Title/Abstract] OR Mitral valvuloplasty [Title/Abstract]
#3 #1 and #2
#4 surgical therapy [Mesh]
#5 Robotic Surgical Procedures [Mesh] OR Video-Assisted Surgery [Mesh] OR Thoracoscopes [Mesh] OR Thoracotomy [Mesh]
#6 totally thoracoscopic [Title/Abstract] OR Traditional thoracotomy [Title/Abstract] OR Conventional Surgery [Title/Abstract]
#7 #4 OR #5 OR #6
#8 #3 AND #7