New Application of the Partial Unilateral Ureteral Obstruction in Neonatal Rat Model

Park, Kwan Hyun

Abstract

PURPOSE: An ureteropelvic junction obstruction, which often leads to a partial ureteral obstruction, is the most common cause of neonatal hydronephrosis. The development of an experimental model for representing a neonatal partial ureteral obstruction is mandatory for the investigation of the pathophysiology and natural course of neonatal hydronephrosis. The applicability of a partial unilateral ureteral obstruction was tested in neonatal rat model.
MATERIALS AND METHODS
Ninety eight newborn Sprague-Dawley rats (mean age: 5.9 days) were subjected to a partial (n=72) or a complete (n=26) unilateral ureteral obstruction. The partial unilateral ureteral obstruction was made by the surgical technique of embracing the ureter with sterilized polyethylene tubing (PE50). The complete unilateral ureteral obstruction was performed by suture ligature of the upper ureter. The degree of obstruction was evaluated by antegrade pyelography and gross findings of the kidneys on the postoperative 2nd and 5th days as well as the postoperative 1st, 2nd, 4th and 6th weeks, respectively.
RESULTS
The overall mortality rate was 19.4%. The mortality rates of the partial and complete obstructions were 22.2 and 11.5%, respectively. The overall success rate of the partial unilateral ureteral obstruction was 52%. The success rate of a partial unilateral ureteral obstruction in a week (63%) was higher than that after more than two weeks (38%).
CONCLUSIONS
This model of a partial unilateral ureteral obstruction in neonatal rats is simple, safe and reproducible. This partial unilateral ureteral obstructive model would be applicable in neonatal rats, especially for short term studies.