Purpose: We created viable bladder tissue by transplantation with immunosup
pression.
Materials and Methods: For bladder transplantation the bladder of newborn B
rown-Norway rats was excised and each was transplanted into a pouch created
in the distal omentum of a 5-week-old Lewis rat. In 15 group 1 rats no imm
unosuppressive agent was used. In 20 group 2 rats 0.6 mg./kg. FK-506 daily
were given intramuscularly until a predetermined day of harvest. Recipient
rats were sacrificed on day 3, 5, 7 or 14 after bladder transplantation, an
d the bladder grafts were harvested and formalin fixed. Hematoxylin and eos
in staining was done to examine bladder graft survival and the degree of re
jection, and immunohistochemical testing was performed for assessing the ve
sical nervous system. In 5 rats in the control group bladder augmentation w
as performed by anastomosing the bladder graft to the native bladder. Each
augmented bladder was harvested 21 days later for histopathological assessm
ent.
Results: Overall bladder graft survival was 96.4%. Each successfully transp
lanted bladder graft appeared macroscopically as a thin walled cyst. In gro
up 1 all bladder grafts showed rejection with cellular infiltration. In gro
up 2 there was mild rejection in 5 rats and no evidence of rejection in the
remaining 15. All group 2 bladder grafts had intact nerve distribution. Bl
adder augmentation was successful in all 5 cases and the mucosa was normal
throughout each augmented bladder.
Conclusion: Because FK-506 successfully prevents rejection, our technique w
ould appear to have the potential for creating viable bladder tissue that m
ay be used for bladder augmentation in cases of vesical exstrophy or neurog
enic bladder.