Ureteral reconstruction: Small intestine submucosa for the management of strictures and defects of the upper third of the ureter

Purpose: We evaluated the effectiveness of small intestine submucosa in ure teral reconstruction. Materials and Methods: We report an experimental study in 6 female pigs weighing between 50 and 60 pounds. The animals were anesthetized, midline laparotomy was per formed and two-thirds of the diameter of the upper third of the left ureter were incised parallel to the ureteral axis, leaving intact only a third of the ureteral wall for a segment of 7 cm. A 5Fr double-J* stent was positio ned to secure patency at all times. The created gap was then bridged with a n small intestine submucosa patch in a cylindrical format, which was subseq uently sutured to the proximal and distal ureteral segment. The right urete r served as our control and simple intubated Davis ureterotomy was performe d. Results: All animals survived the whole followup of 7 weeks. Histologically there was evidence of epithelial regeneration along the segments reconstru cted with small intestine submucosa, supported by a well vascularized colla gen and smooth muscle background. There was no evidence of foreign body rea ction to the graft material. In vivo patency was confirmed by retrograde py elography in the bridged ureters 7 weeks after the initial procedure. All t he ureters without an small intestine submucosa bridge had ureteral stenosi s without evidence of epithelial regeneration. Conclusions: The use of small intestine submucosa is a novel, effective mat erial for the scaffolding of ureteral defects and/or strictures of the uppe r ureter al se,ament in the pig model.