To study the effect of hydrodistention on bladder mucosa and submucosa.

Hydrodistention is a basic diagnostic and therapeutic modality for interstitial cystitis (IC). This objective of this prospective study was to find out if hydrodistention causes any changes in bladder mucosa and submucosa. This study extended from October 1998 to August 2000. A total of 48 patients (25 men, 23 women) were included in the study: 21 patients had IC; 2 had eosinophilic cystitis; 9 had chronic prostatitis; 4 patients had symptoms similar to IC but did not develop glomerulations on scopy (occult IC); 9 patients had some urological disease other than frequency, urgency, and dysuria. The 3 remaining patients had diseases other than urological diseases. The age of patients ranged was from 19 to 70 years. Under anesthesia patient were scoped with a 21-Fr scope. Cold cup biopsy was taken as soon as bladder started filling (approximately 100 mL of fluid inside the bladder). The bladder was then filled to capacity at 80 cm of reservoir height, drained, and then distended again. The second distention was maintained for 3 minutes and the bladder was then drained again. A second cold cup biopsy was taken after draining the bladder a second time. Both the biopsies were studied by a pathologist after staining with hematoxylin and eosin (H&E). There was no difference in predistention and posthydrodistention biopsy in any of the groups. The following parameters were studied: number of layers of bladder mucosa, submucosal edema, infiltration of submucosa by lymphocytes and/or plasma cells, and vascularity and/or congestion of the submucosa. Hydrodistention does not cause any changes in the bladder mucosa and submucosa on histology examination on H&E staining.