AB023. SOH24AB_276. Negative appendectomy rates (NAR) in paediatric pubertal females—is there room for improvement?

Background: Negative appendectomy is a diagnostic error and exposes patients to potential surgical complications. Negative appendectomy rate (NAR) varies widely (15–39%). Paediatric females of child bearing age (CBA) have a higher NAR (as high as 54%). Our objective was to compare the difference in NARs for CBA versus other paediatric patients in a tertiary referral centre.

Methods: A retrospective review of operative records was done (01/06/2021–31/05/2023). All patients (age 1–16 years) who underwent appendectomies for suspected appendicitis were selected; patients having incidental appendectomies as part of other abdominal procedures were excluded. Admission laboratory results, radiology findings, operative findings and histology were collated and the data was analyzed statistically (chi-square test). The NAR for CBA (age >11 years) were compared to that of their male and pre-pubertal female counterparts. White cell count (WCC) and C-reactive protein (CRP) values on admission, as well as radiology findings, for patients with histologically normal appendices were compared to those with confirmed appendicitis.

Results: A total of 560 paediatric patients underwent appendectomies for the time period; 14 were excluded to yield a sample size of 546. There were 317 males (58%), and 229 females (42%). Among them, 121 (22%) were females aged 11–16 years. This subgroup was found to have a NAR of 19.83%, compared to 12.01% for male and pre-pubertal female patients (boys had NAR of 11.99%, and pre-pubertal females 12.04%).

Conclusions: CBA females had significantly higher NARs, but this figure compared favourably to other studies. Laboratory results alone are not definitive; a lower threshold for radiological imaging may be more relevant in this population.

Keywords: Negative appendectomy rate (NAR); normal appendix; paediatric appendicitis; paediatric surgery; post-pubertal females