Negative appendectomy rate in the pediatric population: can we reach near-zero rates? An observational study

Correct diagnosis of acute appendicitis may sometimes be challenging. The Negative appendectomy rate (NAR) has declined in the recent years in Europe and USA, in part due to better diagnostic imaging tools. The aim of this study was to examine the rates of negative appendectomy in our institution, investigate trends in its incidence, and identify possible predicting factors.

A retrospective cohort study, including all patients younger than 18 years of age who underwent an appendectomy between 2007 and 2021 in a single tertiary medical center. Data regarding patient's demographics, laboratory and imaging results, pathological results and clinical outcome were collected.

Between 2007 and 2021, a total of 3937 pediatric patients underwent appendectomy due to a working diagnosis of acute appendicitis. Overall, 143 patients (3.6%) had normal appendix on pathological examination. However, in the last 5 years, the rate of normal appendix was 1.9%, together with an increased rate of pre-operative imaging (from 40% to nearly 100%).

Low NAR under 2% is an achievable benchmark in the era of accessible pre-operative imaging. In unequivocal cases, a secondary survey that includes repeated physical examination, blood work and imaging is recommended and may result in near-zero rates of NAR.