HERNIIA-II trial (Hernia Endoscopic oR opeN repair In chIldren Analysis): a protocol of a multicentre randomised controlled trial to study the (cost-)effectiveness of laparoscopic hernia repair compared to open hernia repair in children 0-16 years.

INTRODUCTION: Inguinal hernia repair is one of the most frequently performed operations in the paediatric population and can be performed according to two approaches: open or laparoscopic. At present, decisive evidence about the best treatment strategy is lacking and consequently, there is an ongoing debate about the most (cost-)effective treatment for the paediatric inguinal hernia. The aim of the Hernia Endoscopic oR opeN repair In chIldren Analysis-trial (HERNIIA2-trial) is to estimate the (cost-)effectiveness of the laparoscopic percutaneous internal ring suturing (PIRS) technique compared with open repair in children aged 0-16 years with a primary unilateral inguinal hernia. METHODS AND ANALYSIS: A national multicentre randomised controlled trial will be performed including 464 children aged 0-16 years with a primary unilateral inguinal hernia. Patients will be randomised between the open or PIRS technique. The primary outcome is the number of reoperations within 2 years after primary surgery. Secondary outcome measures are: operative and postoperative complications, total duration of surgery, postoperative pain, length of admission, time to normal daily activities, cosmetic appearance of the scar, social and healthcare costs and health-related quality of life. Furthermore, cost-effectiveness will be assessed from a societal and healthcare perspective. ETHICS AND DISSEMINATION: The protocol was approved by the ethics committee of the Amsterdam University Medical Hospital. Informed consent will be obtained by parents and, if possible, according to age, by patient. The study will be conducted according to the principles of the Declaration of Helsinki (2013) and in accordance with the Medical Research Involving Human Subjects Act (WMO) and Good Clinical Practice. Study findings will be disseminated through scientific publications, conferences and patient-friendly materials. The national study network of participating centres will facilitate rapid dissemination and implementation within the Netherlands and potentially abroad. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov PRS (ID NCT06451432).