ACKNOWLEDGEMENTS
The authors would like to thank all members of the ESTS learning affairs committee who helped in refining the questionnaire. The authors would also like to thank all participating thoracic surgeons for completing the survey at a difficult time.
Conflict of interest: none declared.

Author contributions
Lieven P. Depypere: Conceptualization; Formal analysis; Funding acquisition; Investigation; Methodology; Project administration; Resources; Software; Supervision; Validation; Visualization; Writing—original draft; Writing—review & editing. Niccolò Daddi: Conceptualization; Data curation; Formal analysis; Funding acquisition; Investigation; Methodology; Resources; Software; Supervision; Validation; Visualization; Writing—original draft; Writing—review & editing. Michael R. Gooseman: Writing—review & editing. Hasan F. Batirel: Conceptualization; Formal analysis; Funding acquisition; Investigation; Methodology; Resources; Software; Supervision; Validation; Visualization; Writing—original draft; Writing—review & editing. Alessandro Brunelli: Conceptualization; Formal analysis; Funding acquisition; Investigation; Methodology; Project administration; Resources; Software; Supervision; Validation; Visualization; Writing—original draft; Writing—review & editing.

Reviewer information
European Journal of Cardio-Thoracic Surgery thanks Kieren G. Mcmanus, Thomas F. Molnar and Jeffrey L. Port and the other, anonymous reviewer(s) for their contribution to the peer review process of this article.