Microsurgical extramucous ureteroureterostomy in rats.

The purpose of this study was to perfect the microsurgical technique of ureteroureterostomy in rats as a contribution to reconstructive surgery of the urinary tract in congenital malformations in newborns and infants. Microsurgical ureteroureterostomy was performed in 100 rats with Nylon and Vicryl 10-0 and 11-0 swaged on a BV-6 and BV-8 needle. Postoperative investigation of renal function and permeability of the anastomoses was realized by macroscopic examination and by IM urography. The healing of the anastomoses was studied at different intervals after operation by histologic and scanning electron microscopic evaluation. Results include 1) per primam healing without stenosis in 98% of the cases; 2) urine proof anastomosis achieved to avoid scarification; 3) extramucous sutures preferable to prevent leakage and also crystallization that rapidly occurs in the rat and 4) tubing or nephrostomy is unnecessary.