Minced urothelium to create epithelialized subcutaneous conduits.
OBJECTIVE
We used in vivo cell expansion to create 3-dimensional subcutaneous conduits lined with an inner layer of autologous urothelial mucosa.


METHODS
Laparotomy and excision of a fifth of the bladder were done in 5 female Yorkshire pigs (Parsons Farm, Westhampton, Massachusetts) under general anesthesia. After mechanical removal of the detrusor muscle the bladder mucosa was minced to obtain 0.2 x 0.8 x 0.8 mm particles, which were attached to the outer surface of latex tubes using a thin layer of fibrin glue. Seven to 10 tubes were placed in the abdominal wall subcutaneous tissue in each original donor pig with tubes lacking particles serving as controls. Biopsy was done 1 to 4 weeks after transplantation for histological evaluation.


RESULTS
One week after transplantation particles were still present in the granulation tissue. At 2 weeks the epithelium was differentiated with transitional uroepithelium facing the lumen, ie toward the tube. No epithelium was detected around control tubes.


CONCLUSIONS
After autologous transplantation of bladder mucosal particles organized in 3-dimensional fashion in pig subcutaneous tissue the transplanted cells proliferated, migrated and reorganized to form a continuous epithelial lining facing the lumen. This novel approach to urothelial transplantation may allow successful formation of a conduit to the bladder or of a neourethra.
Fossum
Magdalena
M
Laboratory of Wound Healing and Gene Transfer, Division of Plastic Surgery, Harvard Medical School, Brigham and Women's Hospital, Boston, Massachusetts, USA. magdalena.fossum@ki.se
Zuhaili
Baraa
B
Bergmann
Juri
J
Spielmann
Malte
M
Hirsch
Tobias
T
Eriksson
Elof
E
D000818:Animals; D001187:Artificial Organs; D004848:Epithelium; D008297:Male; D009092:Mucous Membrane; D040521:Subcutaneous Tissue; D013552:Swine; D023822:Tissue Engineering / Q000379:methods*; D001743:Urinary Bladder; D019459:Urothelium