Received: 7 November 2018
Accepted: 17 January 2019
First Online: 23 January 2019
Ethics approval and consent to participate
: This study was approved by the institutional review board of Seoul National University Hospital (IRB #1704–016-842) and all study protocols were in accordance with guidelines and regulations approved by the ethics review committee for human studies of Seoul National University Hospital.
: Informed consent was waived by the institutional review board due to the retrospective nature of the study design and lack of feasibility.
: The authors of this article are working in one of the high-volume centers performing more than 5 LTs per year. Otherwise, the authors declare no competing interests.
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