The outcomes of right-sided and left-sided colonic diverticulitis following non-operative management: a systematic review and meta-analysis

BACKGROUND: There is no sufficient overview of outcomes in right-sided and left-sided colonic diverticulitis (CD) following non-operative management. This systematic review was conducted to evaluate the recurrence/treatment failure in right-sided and left-sided CD. METHODS: A systematic review was conducted following PRISMA guidelines. MEDLINE, Embase, and Cochrane Library from inception to Dec 2021 were searched. The study characteristics, recurrence/treatment failure, and risk factors for recurrence/treatment failure were extracted. Proportional meta-analyses were performed to calculate the pooled recurrent/treatment failure rate of right-sided and left-sided CD using the random effect model. Logistic regression was applied for the factors associated with the recurrence/treatment failure. RESULTS: Thirty-eight studies with 10,129 patients were included, and only two studies comprised both sides of CD. None of the studies had a high risk of bias although significant heterogeneity existed. The pooled recurrence rate was 10% (95% CI 8–13%, I(2) = 86%, p < 0.01) in right-sided and 20% (95% CI 16–24%, I(2) = 92%, p < 0.01) in left-sided CD. For the uncomplicated CD, the pooled recurrence rate was 9% (95% CI 6–13%, I(2) = 77%, p < 0.01) in right-sided and 15% (95% CI 8–27%, I(2) = 97%, p < 0.01) in the left-sided. Age and gender were not associated with the recurrence of both sides. The treatment failure rate was 5% (95% CI 2–10%, I(2) = 84%, p < 0.01) in right-sided and 4% (95% CI 2–7%, I(2) = 80%, p < 0.01) in left-sided CD. The risk factors for recurrence and treatment failure were limited. CONCLUSION: Non-operative management is effective with low rates of recurrence and treatment failure for both right-sided and left-sided CD although left-sided exhibits a higher recurrence. The recurrence rates did not differ between patients receiving antibiotics or not in uncomplicated CD. Age and sex were not associated with the recurrence although other risk factors were dispersing. Further risk factors for recurrence and treatment failure would be investigated for precise clinical decision-making and individualized strategy.