Development and external validation of preoperative risk models for operative morbidities after total gastrectomy using a Japanese web-based nationwide registry

Background: Total gastrectomy is a relatively difficult and invasive procedure among gastrointestinal surgeries, and major morbidities following total gastrectomy can be serious and fatal. This study aimed to develop and validate preoperative risk models of morbidities associated with total gastrectomy using a Japanese web-based nationwide registry. Methods: The national clinical database was used to retrieve the records of 39,253 patients who underwent total gastrectomy in 1,841 hospitals between January 1, 2011 and December 31, 2012. Results: Mean patient age was 69.1 years, and 73.8% of the patients were male. The overall morbidity rate was 21.5%, which included 8.1% with surgical site infection (SSI), 4.5% with anastomotic leak, 5.0% with pancreatic fistula, 3.7% with pneumonia, 1.9% with prolonged ventilation, and 1.2% with renal failure. Sex, splenectomy, and Brinkman index were selected as common risk factors for SSI, anastomotic leak, and pancreatic fistula. Pancreatectomy was the most significant preoperative risk factor in the risk model of SSI and pancreatic fistula. Need of assistance with activities of daily living, chronic obstructive pulmonary disease, previous cerebrovascular disease, American Society of Anesthesiologists score class 3 and over, presence of esophageal cancer, and body mass index more than 25 were selected as common risk factors for pneumonia, prolonged ventilation over 48 h, and renal failure. Conclusions: We have created the first reported risk models of morbidities associated with total gastrectomy, using a Japanese nationwide database. The risk models developed in this study may be useful to preoperatively predict operative morbidities in patients undergoing total gastrectomy.