Nationwide volume–outcome relationship concerning in-hospital mortality and failure-to-rescue in surgery of sigmoid diverticulitis

Purpose A correlation between the hospital volume and outcome is described for multiple entities of oncological surgery. To date, this has not been analyzed for the surgical treatment of sigmoid diverticulitis. The aim of this study was to explore the impact of the annual caseload per hospital of colon resection on the postoperative incidence of complications, failure to rescue, and mortality in patients with diverticulitis. Methods Patients receiving colorectal resection independent from the diagnosis from 2012 to 2017 were selected from a German nationwide administrative dataset. The hospitals were grouped into five equal caseload quintiles (Q1–Q5 in ascending caseload order). The outcome analysis was focused on patients receiving surgery for sigmoid diverticulitis. Results In total, 662,706 left-sided colon resections were recorded between 2012 and 2017. Of these, 156,462 resections were performed due to sigmoid diverticulitis and were included in the analysis. The overall in-house mortality rate was 3.5%, ranging from 3.8% in Q1 (mean of 9.5 procedures per year) to 3.1% in Q5 (mean 62.8 procedures per year; p < 0.001). Q5 hospitals revealed a risk-adjusted odds ratio of 0.85 (95% CI 0.78–0.94; p < 0.001) for in-hospital mortality compared to Q1 during multivariable logistic regression analysis. High-volume centers showed overall lower complication rates, whereas the failure-to-rescue did not differ significantly. Conclusion Surgical treatment of sigmoid diverticulitis in high-volume colorectal centers shows lower postoperative mortality rates and fewer postoperative complications.