Study protocol for a prospective, multicentre, phase II trial on endoscopic treatment using two fully covered self-expandable metallic stents for benign strictures after hepaticojejunostomy

Introduction The current endoscopic treatment for postoperative benign hepaticojejunostomy anastomotic stricture (HJAS) has a high technical success rate and is highly effective in the short term. However, long-term results have shown a high rate of stenosis recurrence, which indicates an insufficient response to treatment. Three prospective studies on fully covered self-expandable metallic stent (FC-SEMS) treatment for benign HJAS used the stenosis resolution rate as the primary endpoint, and no study has yet used the long-term non-stenosis rate (at 12 months) as the primary endpoint. Methods and analysis We launched the 'saddle-cross study', which will be conducted as a multicentre, prospective intervention of endoscopic treatment using two modified FC-SEMSs (BONASTENT. M-Intraductal) that have been improved for benign stenosis in patients with benign HJAS, with the long-term non-restenosis rate (at 12 months) as the primary endpoint. This study aims to evaluate the long-term non-restenosis rate (at 12 months) and safety of the saddle-cross technique for benign HJAS. We plan to enrol 50 participants. Ethics and dissemination This study has been approved by the Certified Review Board of the National Cancer Center, Japan (CRB3180009). The results will be reported at various conferences and published in international peer-reviewed journals.