Rare causes of acute abdomen in a paediatric surgery department: a 5-years review.

Aims: Acute abdomen is a common indication to surgery in paediatric emergency departments. Appendicitis is the most frequent diagnosis, followed by bowel obstruction and female genital conditions. Some rare aetiologies may lead to challenges in surgical management. Aim of this study is to analyse the distribution of rare causes of acute abdomen in patients undergoing emergency surgery in the past five years at our centre. Methods: Records of patients undergone urgent abdominal surgery were retrospectively reviewed from 2015 to 2019. Information relative to age, sex, underlying pathology, and surgery was recorded. The inclusion criteria were age <18 years and undergoing abdominal surgery. Neonates were excluded. Results: The study population consisted of 957 patients. Median age was 9.7 years. Surgical procedure was laparoscopic in 22%, open in 78%. Common diagnoses were appendicitis in 815 patients, bowel obstruction in 72, adnexal and gynaecological pathology in 43, trauma in 9, complicated Meckel's diverticulum in 8. Rare findings included omental pathology (2), endometriosis (2), ectopic pregnancy (1), intestinal duplication (1), internal hernia (1), Amyand's hernia (1), epiploic appendix torsion (1), accessory spleen torsion (1). Conclusions: The aetiologies of acute abdomen in children vary depending on the age. Appendicitis is the most common surgical cause of acute abdomen, followed by other causes. Differential diagnosis, including rare pathologies, is required to predict the right surgical approach and to apply the proper treatment. Imaging techniques sometimes still result too invasive or insufficient, whereas the widespread use of laparoscopy may render surgical exploration acceptable in selected cases.