Urothelial lined colocystoplasty in a sheep model.

Nineteen lambs underwent colocystoplasty using a segment of demucosalised sigmoid colon, and were compared to 14 control animals. Nine animals had a procedure which included the addition of the muscle patch to an autoaugmented bladder, and 10 had a clam cystoplasty with the denuded colon. Six months after the procedure, the average compliance value for the autoaugmentation colocystoplasty bladders was 5.7 +/- 1.7 ml/cm H2O, compared to 6.9 +/- 2.2 ml/cm H2O for the clam-demucosalised colocystoplasty group, and 11.0 +/- 4.8 ml/cm H2O for the control group. Whereas at 12 months the compliance values were 9.2 +/- 3.5, 10.7 +/- 5.1 and 9.1 +/- 3.7 ml/cm H2O for each of the groups, respectively. The sheep colonic muscle tolerated the demucosalisation procedure poorly, reflected in an inflamed, haemorrhagic colonic segment in the animals sacrificed within 1 month; this may have been the reason for the poor results, and explain why the autoaugmentation did not improve the outcome. Colonic mucosal regrowth occurred in 5, and was related to the demucosalisation technique.