Comparison of classification systems for acute diverticulitis and updating of Helsinki staging.

BACKGROUND

Helsinki classification for acute colonic diverticulitis, based on radiological and clinical parameters, stratifies patients according to their prognosis and recommended treatment into five stages. This study aims to update Helsinki classification to improve it in patients with abscesses and peritonitis and validate the classification by comparing it with other classifications of diverticulitis.

METHODS

This was a retrospective cohort study. Patients treated for acute colonic diverticulitis of any stage between 2011 and 2017 and for stages 4 and 5 between 2006 and 2017 in Helsinki University Hospital were included. Performance of classifications was tested with area under the receiver operating characteristic curve analysis.

RESULTS

In total, 2,361 patients were included. Receiver operating characteristic curve analysis showed the highest specificity and sensitivity for abscess cutoff point 50 mm in intensive care unit (ICU) admissions, discharge within 14 days, and operative treatment. Patients with Helsinki stage 4 fecal peritonitis had significantly more ICU admissions (38% vs. 12%, p = 0.005) and less ICU-free days (median, 24 vs. 26; p < 0.03), and fewer were discharged within 14 days (48% vs. 72%, p = 0.03) than patients with Helsinki stage 4 purulent peritonitis. Outcomes were similar between stage 4 fecal subgroup and stage 5 patients. Based on these findings, in the updated Helsinki 2.0 classification, abscess diameter cutoff between Helsinki stages 2 and 3 was changed to 50 mm, and fecal peritonitis was defined as belonging to Helsinki stage 5 diverticulitis. Helsinki 2.0 classification had generally at least equal area under the curve (AUC) values (AUC, 0.89-0.95) for mortality and morbidity compared with other classifications of diverticulitis (AUC, 0.83-0.95).

CONCLUSION

Updated Helsinki 2.0 classification is an easy-to-use robust pre- and intraoperative classification for acute diverticulitis accurately predicting outcomes and guiding treatment choices.

LEVEL OF EVIDENCE: Diagnostic Test or Criteria; Level III.