1. Department of Colorectal Surgery, Tianjin Union Medical Center, Hongqiao District, Tianjin 300121, China
2. Department of Cardiothoracic Surgery, Army Hospital of the 80th Group, Weicheng District, Weifang 261021, Shandong, China
3. Nankai University, No. 94 Weijin Road, Nankai District, Tianjin 300074, China