Ileocystoplasty in rats: metabolic, renal and enteropatch changes in a mid- and long-term follow-up.

INTRODUCTION

Bladder augmentation predisposes humans to many metabolic, renal and enteropatch changes. Our aim was to evaluate in a rat model of ileocystoplasty mid- and long-term urinary, metabolic, renal and graft changes.

MATERIALS AND

METHODS

We performed an ileocystoplasty and a sham operation in 30 rats. Seven augmented rats and 3 sham-operated animals were euthanized after 1, 3 and 6 months. We performed urinalysis, urine culture and blood sampling for serum electrolytes and urea. Histopathological changes of the ileal patch and kidneys were also evaluated.

RESULTS

The urine cultures were positive in 14.3, 57 and 71%, respectively, 1, 3 and 6 months after surgery. Urinary pH, serum chloride and urea of the augmented group were significantly higher. Bladder calculi were formed in 23.8% of ileocystoplasty. Histopathological examination showed urothelialization of the graft with hyperplastic/metaplastic changes. The kidneys showed glomerular depletion and a marked distal tubular ectasia.

CONCLUSIONS

Our data showed that, in a mid- and long-term follow-up, rat bladders subjected to ileocystoplasty displayed hyperchloremic metabolic acidosis, electrolyte imbalance, enhanced serum blood urea levels and glomerular/tubular changes. Hyperplastic and/or metaplastic changes at the junctional zone were observed. Our experimental results suggest that frequent monitoring of renal function and surveillance of humans who have undergone ileocystoplasty are recommended.