AB023. SOH25_AB_146. Negative appendectomy demographics and rates in paediatric patients

Background: Appendicectomy is the most commonly performed emergency surgery in the paediatric population; however, preoperative diagnosis can be challenging. The potential for additional differential diagnoses of ovarian pathology in females adds to the challenging nature of diagnosis. Negative appendectomies subject patients to the risks of an operation (general anaesthetic, infection, bleeding, etc.) with minimal benefit. This study aimed to determine the negative appendicectomy rate (NAR) in our institution and compare demographics in post-pubertal females and all other paediatric patients.

Methods: A retrospective review of emergency theatre operative records over four years (1/06/2020 to 31/05/2024) was performed. Procedure performed, haematological results [C-reactive protein (CRP), white blood cell count (WCC), hemoglobin (Hb) and neutrophils], radiological findings and histology reports were collected and analysed statistically using the R Stats Package.

Results: A total of 805 patients (mean age 11±3 years; 46% female) underwent appendicectomies. In total, 250 (31%) were histologically normal. Among the cohort, 239 patients (29.7%) were post-pubertal females (>11 years old), and in this group the NAR was 40% (n=96). Comparatively, the NAR was 36% for pre-pubertal females and 25% for the combined group of males and pre-pubertal females (P<0.0001). And 306 patients (38%) underwent ultrasound (US) preoperatively (59% postpubertal, 36% prepubertal and 27% male). The positive predictive value (PPV) of US for all groups was 74%.

Conclusions: One third of all paediatric appendicectomies were histologically normal. Postpubertal female patients had a higher NAR, suggesting females require a greater work up as compared to their male counterparts to definitively diagnose appendicitis prior to surgery.

Keywords: Appendicitis; negative appendectomy rate; paediatrics; post-pubertal female; ultrasound (US)