ExtrAperitoneaL Plasty vs Intraperitoneal oNlay mEsh in ventral hernia repair - a multi-center randomized controlled trial: the ALPINE study protocol.

Introduction: Minimally invasive ventral hernia repair (MIVHR) is a frequently performed surgical procedure to address primary or incisional ventral hernias and is recommended by numerous societies. Various techniques are available for MIVHR, including the intraperitoneal onlay mesh (IPOM) procedure and the enhanced view totally extraperitoneal (eTEP) approach. While both techniques are increasingly applied, they continue to be subject of controversy in literature. Well-designed randomized controlled trials comparing both procedures are lacking. The objective of this study is to investigate whether eTEP is associated with a decreased level of postoperative pain compared to IPOM.

Methods: This is a prospective, multi-center, randomized, and blinded controlled trial. Patients presenting with primary or incisional epigastric, umbilical, or infraumbilical hernia with a transverse diameter >1 cm and ≤4 cm, or multiple hernias with a cumulative transverse diameter ≤4 cm, will be randomly assigned to undergo either IPOM or eTEP procedures. All patients and assessors of the study outcomes are blinded to the treatment allocation. The trial will be conducted at the St. Clara Hospital Basel, at the University Hospital Basel (Switzerland) and at the Innklinikum Altötting (Germany). It remains open for additional sites to be included. The multi-center design is chosen to minimize environmental bias related to perioperative anesthesiology and nursing care and to enhance participant recruitment. The primary outcome of this study is to evaluate postoperative pain (numeric rating scale and Patient-Reported Outcome Measurement Information System Pain Intensity Short Form 3a) 24 hours after the surgical procedure. Secondary outcomes include the assessment of pain at different times, length of hospital stay, operative time, readmission rate, intraoperative, and postoperative adverse events.