Ureter reconstruction using a biotube in a canine model: A pilot stud.

Introduction: Ureteral injuries can lead to renal dysfunction, and conventional treatments such as ureteral stents and autologous tissue grafts have limitations. This study aimed to evaluate the biocompatibility of a "biotube" created using in-body tissue architecture (iBTA) technology for ureteral reconstruction in a canine model. Methods: Biotubes were implanted in dogs to replace a segment of the ureter. Ureteral stents were used to prevent obstruction. Autopsies were performed 2-3 months after implantation, and the implantation sites were examined histologically to assess tissue regeneration, vascularization, and potential inflammatory reactions. Results: Ureteral stenting effectively prevented obstruction and ensured adequate urinary flow during the observation period. All biotubes were significantly shortened after implantation. No signs of inflammation or foreign body reactions were recorded, indicating good biocompatibility. Although epithelial cell invasion was observed, muscle tissue migration and angiogenesis were limited. Conclusions: Biotubes demonstrate potential as temporary ureteral substitutes; however, improvements in epithelialization and muscle tissue migration are necessary for successful long-term ureteral regeneration. Further experimental studies are required to evaluate their clinical utility as scaffold materials for ureteral reconstruction.