Impacts of COVID-19 pandemic on short-term outcomes of low anterior resection performed in hospitals with different surgical volumes

Aim

To evaluate the impact of the coronavirus disease (COVID-19) pandemic on short-term outcomes of low anterior resection (LAR) across hospitals classified by surgical volume.

Methods

Data of patients who underwent elective LAR for rectal cancer between 2018 and 2022 were obtained from the National Clinical Database of Japan. Hospitals were categorized into high-, medium-, and low-volume groups. Each group was constituted to represent approximately one-third of all surgeries performed between 2018 and 2019. The standardized morbidity/mortality ratios (SMRs) of Clavien–Dindo grade ≥3 (CD ≥ 3) complications were the primary endpoint. The secondary endpoints included anastomotic leakage, pneumonia, and surgical mortality.

Results

This study analyzed 91 800 cases of elective LAR, with 10.5% experiencing CD ≥ 3 complications, 8.8% anastomotic leakage, 0.9% pneumonia, and 0.5% surgical mortality. Despite COVID-19, SMRs of CD ≥ 3 complications decreased from 2018 to 2022 across all groups. However, increases in the rates and SMRs of CD ≥ 3 complications were observed in low-volume hospitals around mid-2020, followed by a decline. Anastomotic leakage showed similar trends. The rates and SMRs of pneumonia and surgical mortality remained unchanged. Notably, anastomotic leakage rates were 7.6%, 8.9%, and 10.0% in high-, medium-, and low-volume hospitals, respectively, indicating superior outcomes in high-volume hospitals.

Conclusion

Early COVID-19 waves may have disproportionately affected low-volume hospitals. However, the decline in SMRs of CD ≥ 3 complications from 2018 to 2022 across all three groups suggests the robustness and resilience of surgical services for rectal cancer in Japan. The potential disparity in short-term outcomes among hospitals is a new concern.