What are the differences between the three most used classifications for acute colonic diverticulitis? A comparative multicenter study

Background: Acute left-sided colonic diverticulitis is one of the most common clinical conditions encountered by surgeons in the acute setting. Currently, the most popular classifications, based on radiological findings, are the modified Hinchey, American Association for the Surgery of Trauma (AAST), and World Society of Emergency Surgery (WSES) classifications. We hypothesize that all classifications are equivalent in predicting outcomes. Methods: This is a retrospective study of 597 patients from four medical centers between 2014 and 2021. Based on clinical, radiological, and intraoperative findings, patients were graded according to the three classifications. Regression analysis and receiver operating characteristic curve analysis were used to compare six outcomes: need for intervention, complications, major complications (Clavien-Dindo >2), reintervention, hospital length of stay, and mortality. Results: A total of 597 patients were included. Need for intervention, morbidity, and reintervention rates significantly increased with increasing AAST, modified Hinchey, and WSES grades. The area under the curve (AUC) for the need for intervention was 0.84 for AAST and 0.81 for modified Hinchey ( p = 0.039). The AUC for major complications was 0.75 for modified Hinchey and 0.70 for WSES ( p = 0.009). No differences were found between the three classifications when comparing AUCs for mortality, complications, and reintervention rates. Conclusion: The AAST, WSES, and modified Hinchey classifications are similar in predicting complications, reintervention, and mortality rates. American Association for the Surgery of Trauma and modified Hinchey scores result the most adequate for predicting the need for surgery and the occurrence of major complications. Level of evidence: Prognostic and Epidemiological; Level III.