title: Use of single layer small intestinal submucosa for long segment ureteral replacement: a pilot study.
abstract: OBJECTIVE
  Previous studies have demonstrated successful use of small intestinal submucosa (SIS) as a tube for replacing short segment (11 mm) proximal ureteral defects. However, such small segment ureteral defects could be managed by resection re-anastomosis. We evaluated the use of 1-layer SIS as a tube for the replacement of long segment ureteral defects.
  
  
  METHODS
  The ureters of 5 female mongrel dogs were accessed through a median laparotomy incision. A 4 cm segment of mid ureter was resected on the right side. The right ureteral segments were replaced by tubularized SIS segments using 6-zero polydioxanone interrupted sutures. Internal pigtail stents were left for 6 weeks. All animals were sacrificed at 12 weeks. Ureteral patency was assessed by excretory urography and magnetic resonance urography 7 and 12 weeks after the initial procedures. Inflammation and regeneration were assessed histologically.
  
  
  RESULTS
  At 12 weeks all ureters on the experimental side were completely occluded with significant hydroureteronephrosis and the subsequent deterioration of kidney function. At autopsy there was failure to calibrate any of the experimental ureters with a 3Fr catheter. Although histologically urothelium and muscular cells had proliferated over the graft, they were embedded in an intense fibrotic and inflammatory process.
  
  
  CONCLUSIONS
  Technically 1-layer SIS was easily modeled, providing the conditions for watertight anastomosis. The regeneration of urothelium and muscle was induced and supported by the graft. However, functional replacement was not successful. One-layer SIS is not a suitable material for replacing long segment (4 cm) ureteral defects.
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: El-Assmy
authors.forename: Ashraf T
authors.initials: AT
authors.lastname: Hafez
authors.forename: Mohamed T
authors.initials: MT
authors.lastname: El-Sherbiny
authors.forename: Mohamed A B D
authors.initials: MA
authors.lastname: El-Hamid
authors.forename: Tarek
authors.initials: T
authors.lastname: Mohsen
authors.forename: Eman M
authors.initials: EM
authors.lastname: Nour
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Bazeed
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D007413:Intestinal Mucosa / Q000637:transplantation*; D007421:Intestine, Small / Q000637:transplantation*; D010865:Pilot Projects; D012038:Regeneration; D014513:Ureter / Q000502:physiology / Q000601:surgery*; D013520:Urologic Surgical Procedures / Q000379:methods