Fig. 1

Endoscopic views with regard to leakage grading. a Anastomosis on day 6 after the operation. b Leakage grade 1a: dehiscence of the anastomosis less than a quarter of the circumference without a cavity. c Leakage grade 1b: rosy tubular stomach, dehiscence of the anastomosis less than a quarter of the circumference, with a cavity. d Leakage grade 2: rosy tubular stomach, dehiscence of the anastomosis more than a quarter of the circumference, with a cavity. e Leakage grade 3: the necrotic mucosal layer of the tubular stomach. f Leakage grade 4: the necrotic wall of the tubular stomach