Tissue engineered tubular construct for urinary diversion in a preclinical porcine model.
OBJECTIVE
The ileal conduit has been considered the gold standard urinary diversion for patients with bladder cancer and pediatric patients. Complications are mainly related to the use of gastrointestinal tissue. Tissue engineering may be the technical platform on which to develop alternatives to gastrointestinal tissue. We developed a collagen-polymer conduit and evaluated its applicability for urinary diversion in pigs.


METHODS
Tubular constructs 12 cm long and 15 mm in diameter were prepared from bovine type I collagen and Vypro® II synthetic polymer mesh. Characterized tubes were sterilized, seeded with and without primary porcine bladder urothelial cells, and implanted as an incontinent urostomy using the right ureter in 10 female Landrace pigs. At 1 month the newly formed tissue structure was functionally and microscopically evaluated by loopogram and immunohistochemistry, respectively.


RESULTS
The survival rate was 80% with 1 related and 1 unrelated death. By 1 month the collagen was resorbed and a retroperitoneal tunnel had formed that withstood 40 cm H(2)O water pressure. In 5 cases the tunnel functioned as a urostomy. Histological analysis revealed a moderate immune response, neovascularization and urothelial cells in the construct lumen. The polymer mesh provoked fibroblast deposition and tissue contraction. No major differences were observed between cellular and acellular constructs.


CONCLUSIONS
After implanting the tubular constructs a retroperitoneal tunnel was formed that functioned as a urinary conduit in most cases. Improved large tubular scaffolds may generate alternatives to gastrointestinal tissue for urinary diversion.
Department of Urology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. p.geutjes@uro.umcn.nl
Paul
P
Geutjes
Luc
L
Roelofs
Henk
H
Hoogenkamp
Mariëlle
M
Walraven
Barbara
B
Kortmann
Robert
R
de Gier
Fawzy
F
Farag
Dorien
D
Tiemessen
Marije
M
Sloff
Egbert
E
Oosterwijk
Toin
T
van Kuppevelt
Willeke
W
Daamen
Wout
W
Feitz
D000199:Actins / Q000032:analysis; D000818:Animals; D024042:Collagen Type I; D004867:Equipment Design; D005260:Female; D007633:Keratins / Q000032:analysis; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011098:Polyglactin 910; D011126:Polypropylenes; D013526:Surgical Mesh; D013552:Swine; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D014547:Urinary Diversion / Q000379:methods*; D014746:Vimentin / Q000032:analysis; D014945:Wound Healing / Q000502:physiology
D000199:Actins; D024042:Collagen Type I; D011126:Polypropylenes; D014746:Vimentin; C510058:VyproII; D011098:Polyglactin 910; D007633:Keratins