Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40981-021-00443-x/MediaObjects/40981_2021_443_Fig1_HTML.png)
Flow chart for patient’s selection. Flow diagram detailing the selection of patients included in the retrospective analysis. Ninety-one patients were excluded due to non-curative surgery, multiple procedures for the cancer during the study period, incomplete records, and receiving both forms of anesthesia during surgery