Regeneration of the canine urinary bladder mucosa after complete surgical denudation

To study the site of origin of epithelial regeneration in the urinary bladder after surgical denudation, we completely obliterated the bladder mucosa in 17 dogs, using the neodymium: YAG laser. Bladder-mapping studies showed that the regenerating cells arose from the epithelium of the terminal ureters and urethra. Experimental construction of isolated bladder pouches confirmed these findings and demonstrated that urine flow was not essential for reepithelialization. These results are relevant to the treatment of patients with multifocal carcinoma in situ of the bladder. Although the entire bladder can be denuded successfully, the studies demonstrate that the procedure might fail if the sources of epithelial regrowth, the distal ureters and urethra, contain untreated carcinoma in situ.