72298 - High mortality after surgery for perforated diverticulitis Hinchey grade IV was mediated by sepsis

Introduction Studies of perforated diverticulitis have mainly been focused on choice of surgical method and few have included faecal peritonitis, Hinchey grade IV. The aim was to study a national cohort of patients operated for Hinchey IV and to compare with a national cohort Hinchey grade III. Method The study cohort consisted of all patients operated for perforated diverticulitis, Hinchey grade III and IV, in Sweden during 2016-2018. The cohort was identified through the Swedish In-Patient registry with a combination of ICD-10 codes for diverticulitis and operation codes (NOMESCO). All medical records were collected to retrieve data on diagnosis, operation and clinical outcomes. Data from the Cause of Death registry and Cancer registry were collected. Result Out of 1300 identified patients 669 were operated for perforated diverticulitis Hinchey grade III-IV with 170 Hinchey grade IV. Female sex was more common in Hinchey IV (66% vs 52%) as was immunosuppression. Age, BMI and co-morbidity did not differ. Sepsis was present in 41% among Hinchey IV compared to 18% for Hinchey III. Mortality within 2 years was higher in Hinchey IV (31% vs 21%) largely due to diverticulitis-specific mortality (15.2% vs 6.8%). Risk of death due to diverticulitis was higher for Hinchey IV (HR 1.76 (1.03; 3.00)). Sepsis increased the risk of death due to diverticulitis (HR 2.84 (1.65; 4.93)). Discussion Mortality was high after surgery for perforated diverticulitis, especially for Hinchey IV. Although Hinchey grade had an influence independently, sepsis was a strong mediator for death. To reduce mortality emphasis on sepsis care seems warranted.