Effects of the COVID‐19 pandemic on short‐term postoperative outcomes of emergency surgery for gastroduodenal perforation: A nationwide study in Japan based on the National Clinical Database

Abstract Aim To examine the potential negative effects of the COVID‐19 pandemic on short‐term postoperative outcomes of emergency surgery for gastroduodenal perforation in Japan. Methods A total of 7973 cases of gastroduodenal perforation from 2019 to 2021 were retrieved from the National Clinical Database (NCD), which includes >95% of surgical cases in Japan. Data were analyzed nationally and in subgroups for subjects in areas with high infection levels (HILs). Postoperative 30‐d mortality, surgical mortality, and complications (Clavien–Dindo (CD) grade ≥3) were examined. Months were considered to have significantly high or low mortality or complication rates, if the 95% confidence interval (CI) of the standardized mortality (morbidity) ratio (SMR) does not contain 1. Results Nationally, data from 2019 vs 2020 and 2021 showed 30‐d mortality of 175 (6.7%) vs 398 (7.4%), surgical mortality of 250 (9.5%) vs 537 (10.1%), and complications (CD ≥3) of 558 (21.2%) vs 1163 (21.8%). Among these data, the only significantly high SMR was found for complications in July 2020 (1.36 [95% CI: 1.001–1.80]). In areas with HILs, data from 2019 vs 2020 and 2021 indicated 30‐d mortality of 91 (6.3%) vs 215 (7.3%), surgical mortality of 135 (9.4%) vs 294 (10.0%), and complications (CD ≥3) of 304 (21.1%) vs (23.1%). In these data, no month had a significantly high SMR. Conclusion The COVID‐19 pandemic had few negative effects on outcomes after surgery for gastroduodenal perforation. These findings suggest that the emergency system for gastroduodenal perforation in Japan was generally maintained during the pandemic.