Evaluation of safety and efficacy of robotic-assisted pancreaticoduodenectomy (SWARS study): a study protocol for a multi-center randomized phase-2 trial

Pancreaticoduodenectomy (PD) remains the standard procedure for tumors of the pancreatic head region but is one of the most technically demanding abdominal procedures. Robot-assisted PD (Robot-PD) is a promising minimally invasive alternative, with retrospective and early randomized studies suggesting its potential benefits; however, concerns remain regarding its surgical quality and safety. The Japan Society of Hepato-Biliary-Pancreatic Surgery has implemented a strict certification system for surgeons and institutions to ensure high-quality hepatopancreatobiliary surgeries. To date, no randomized trial has evaluated the safety and efficacy of Robot-PD under these rigorous standards. This study aims to evaluate the safety and efficacy of Robot-PD. This multicenter, prospective, open-label, randomized phase 2 trial will be conducted at four certified high-volume centers in Japan. Eligible patients will be aged 20–85 years with resectable tumors of the pancreatic head region without radiological evidence of major vascular invasion. The participants will be randomized in a 2:1 ratio to Robot-PD or open PD using a centralized web-based system with stratification based on institution, main pancreatic duct diameter ≥ 3 mm, and a history of pancreatitis or cholangitis. The primary endpoint will be the incidence of postoperative complications of Clavien–Dindo grade ≥ 3a in the Robot-PD group. The secondary endpoints will include intraoperative outcomes, postoperative complications and recovery (with comparisons between Robot-PD and open PD), pathological findings, oncological outcomes, quality of life, and cost. The target sample size will be 100 patients, allowing for a 10% dropout rate, with an anticipated accrual period of 2 years. Statistical analyses will follow a predefined plan based on the intention-to-treat principle. This trial represents the first prospective, randomized evaluation of Robot-PD in Japan under a certified training system at high-volume hepatopancreatobiliary centers. The study aims to establish benchmark outcomes for Robot-PD, clarify its safety relative to a predefined complication threshold, and compare its efficacy with that of open PD. The results of this study are expected to inform surgical practice and contribute to future guidelines for Robot-PD in Japan and internationally. This trial was registered with the Japan Registry of Clinical Trials on August 25, 2025 (jRCT: 1030250312).