Autoaugmentation omentocystoplasty in a sheep model.

OBJECTIVE

To develop a sheep model of autoaugmentation omentocystoplasty and study the histologic appearance, and to compare the urodynamic results with a control group.

METHODS

Ten male lambs underwent a bladder autoaugmentation reinforced with an omental patch. Three were culled early, to study urothelial survival and inflammatory changes. One was sacrificed at six months to assess late histologic changes; five sheep had a urodynamic study at that stage and two died of unknown causes without further investigation. A group of seven six-month-old male sheep, of similar weights, formed the control urodynamic group.

RESULTS

The urothelial lining remained viable under the omentum, but marked inflammation and heterotopic calcification were seen within the subepithelial tissues in most of the animals. The histologic changes were reflected in the bladder dynamic data, which were no better than the control group; the average compliance value was 9.2 +/- 6.4 mL/cm H2O, compared to the control group figure of 11.8 +/- 5.2 mL/cm H2O.

CONCLUSIONS

It would appear that autoaugmentation alone does not usually produce bladder augmentation in the sheep.