Nationwide Trends in Short-Term Outcomes After Low Anterior Resection for Rectal Cancer: A Pre- and Post-COVID-19 Analysis From the Japanese National Clinical Database, 2018–2023

Abstract

Aim

This study evaluated the short-term outcomes of low anterior resection for rectal cancer in Japan before and after the COVID-19 pandemic, with a particular focus on the timing of its reclassification within Japan in May 2023.

Methods

Using data from the Japanese National Clinical Database, we analyzed 109 754 low anterior resection cases between January 2018 and December 2023, categorized into pre-pandemic (February 2020 and earlier), pandemic (March 2020–April 2023), and post-pandemic (May 2023 onward) periods. Trends in the number of low anterior resection cases, postoperative intensive care unit utilization, and complications, including anastomotic leakage and pneumonia, were examined. Standardized morbidity ratios were used to adjust for risk and assess trends over time.

Results

The number of low anterior resection cases declined during the pandemic but returned to pre-pandemic levels thereafter. The postoperative intensive care unit admission rates remained stable, with a slight increase post-pandemic. The incidence of major complications gradually declined from pre-pandemic to post-pandemic, with anastomotic leakage rates decreasing from 9.8% to 7.1% and the standardized morbidity ratio for anastomotic leakage decreasing from 1.0 to 0.8, reflecting improved outcomes. The number of robot-assisted surgeries significantly increased from 246 cases in March 2020 to 535 in May 2023, and their proportion among total surgeries also rose from 16.8% to 41.2%.

Conclusion

Despite initial challenges, the healthcare system of Japan effectively managed rectal cancer surgeries during and after the pandemic. Robotic surgery became more widely adopted, and complication rates improved, demonstrating resilience and adaptability in surgical care.