Efficacy of Short vs. Long Course Antibiotics in Treatment of Hinchey 3 and 4 Diverticulitis

Authors:
Abanoub Awad, Cara Kollwitz, Isaac Theerman, Jason Beckermann, Jennifer Rich, Justin York, Kirstin Kooda, Maria Linnaus, Sara Herrick, Theodore Yang

Body of Abstract:
Background: Antibiotic therapy plays a critical role in the post-operative management of complicated diverticulitis. Traditionally, treatment has involved antibiotics until signs of infection subside, typically spanning 7-14 days. Recent studies, including the STOP-IT trial and national guidelines, support short-course antibiotics once definitive source control has been obtained. Shorter courses are favored to reduce costs and adverse effects associated with prolonged use. In addition, short-course antibiotic regimen supports antibiotic stewardship objectives. We observed variation in clinical practice for patients with extensive intra-abdominal infections such as Hinchey 3 and 4 diverticulitis and sought to evaluate outcomes in this population.
Methods: Retrospective chart review was performed of all adults (>18 years old) patients who underwent a sigmoid colectomy with stoma secondary to Hinchey class 3 and 4 diverticulitis at a large hospital system across several states from January 1st, 2018, to December 31st, 2023. Patients were divided into two groups: those with short-course antibiotics (SAC group) (≤5 days) and those with long-course antibiotics (LAC group) (>5 days).
The primary outcome was composite superficial surgical-site, incisional, organ space infection or death within 30 days after the procedure.
Results: A total of 133 met inclusion across 4 major hospital sites; 51.1% were male. Most common comorbid condition among all patients was HTN (53%) while most common ASA scores were ASA 3, ASA 2 and ASA 4 (57.1%, 21.1% and 20.3%, respectively). LAC group patients had higher ASA scores (p=0.001), higher incidence of acute kidney injury on admission (p=0.0135) and had higher rates of immune compromise (p=0.0002) than SAC group patients. Composite rates of 30-day mortality, superficial, incisional and organ space infections occurred 8 of 53 patients (15.1%) in SAC group and 27 of 80 patients (33.8%) in LAC group, (p=0.02601), When broken down by SSI type, there were similar rates of superficial, deep incisional and organ space infection between the groups. Mortality rate was higher in LAC group (10% vs 0%, p = 0.0213).

Conclusion: Longer antibiotic therapy for Hinchey 3-4 diverticulitis does not improve composite mortality, SSI, and organ space infection in patients undergoing sigmoidectomy and stoma. In our practice patients with higher ASA scores, immunocompromised state, and acute kidney injury were more likely to receive a longer course of antibiotics. Mortality rates were higher in longer antibiotic therapy group potentially indicating severity of illness and aggressive treatment to prevent a negative outcome.