Bladder autoaugmentation with protective autologous uterine flap. Experimental study in the rat.

INTRODUCTION

Enterocystoplasties are associated to complications. We developed a surgical technique for bladder autoaugmentation using autologous uterine flap in the rat, to try and improve the post-surgical evolution.

METHODS

36 female Wistar rats were randomly allocated into following groups: Group 1: Control (n = 12) for analytical parameters, Group 2: Sham-operation hysterocystorrhaphy (n = 12) and Group 3: Bladder autoaugmentation with autologous uterine flap (n = 12). Two weeks after surgery ultrasound examination of the bladder was performed. At 8 weeks and 24 weeks, blood and urine samples were taken. Post-mortem evaluation was performed and urogenital apparatus removed for gross and microscopic examination. The statistical analysis was done using the Kruskall-Wallis and the extension of the Fisher's exact test. Significance was set at 5% (p < 0.05).

RESULTS

Serum chemistry, blood count and peripheral blood smears, electrolytes and urinary parameters were all within the normal range for the rat. No abnormal findings were observed during ultrasound examination. There was no mortality or other surgical complications. Post-mortem evaluation revealed no dilation of bladder, uterus or upper urinary tract. Uroliths were not observed. Histology of the augmented area demonstrated an excellent union between the bladder and the protective uterine flap. A normal urothelial layer was maintained.

CONCLUSIONS

The use of autologous uterine flap to perform bladder autoaugmentation in the rat proved a safe and suitable surgical technique to augment the bladder. The major advantage is the avoidance of the complications observed in other surgical techniques for bladder augmentation, like enterocystoplasties, where gastrointestinal tract epithelium is incorporated into the urinary tract.