Age as an Exclusion Criterion for Non-Operative Management in Simple Acute Appendicitis in Children

Aim: Non-operative management (NOM) for simple acute appendicitis (SAA) is an acceptable mode of treatment in healthy children. Previous studies of NOM routinely excluded young children (<5y), however the effect of age on NOM failure has not been directly assessed. Efficiency of NOM in young adults is questionable. Therefore, adolescents may also be at greater risk of NOM failure. Our aim was to investigate the effect of age on NOM failure. Methods: A retrospective analysis of children with SAA who received NOM between 1.1.2019-30.06.2021 at our Institution. NOM failure was defined by subsequent appendectomy. Age was assessed as a continuous variable and we also compared different age subgroups. Results: 151 children were included (60% male), mean age 11.2±3.2y (range 5-17). Overall, 66 children (44%) failed NOM, 90% of them within the first year (median 7 weeks). 10% of the cohort were <6y and 33% of them failed NOM (p=0.39). Per 1y increase in age, the odds of NOM failure increased by 12% (p=0.027). Children >14y had 2.46 times higher odds to fail NOM (p=0.03). These higher odds remained after adjusting for appendiceal diameter and appendicolith. Linear regression showed a decrease by a factor of 12 in time to NOM failure with every 1y increase in age (β=-12, p=0.09). Conclusions: The risk of NOM failure in children increases with age, therefore age should be a considered when deciding on the optimal management of SAA, especially in adolescents. Effectiveness of NOM in children younger than 6y is non-inferior to operative management and therefore should not be excluded.