Evaluation of the duration of ureteral stenting following endopyelotomy: Animal study

The purpose of the present paper was to evaluate whether it is possible to reduce the duration of ureteral stenting following endopyelotomy, and thus reduce side-effects.

Seventeen pigs were used. They were distributed at random into three groups. The study was divided as follows: phase I included baseline study of the urinary system and the creation of a ureteropelvic junction obstruction (UPJO) model. Phase II, 1 month later, consisted of diagnosing UPJO, Acucise endopyelotomy of the same, and the placement of a ureteral stent. Ureteral stents were left in situ for 1 week in group I, for 3 weeks in group II and 6 weeks in group III. Phase III, 3 months after treatment, consisted of follow up and post-mortem studies of the animals. The following procedures were carried out during each phase: ureteropelvic junction (UPJ) diameter measurement, ultrasound percutaneous and endoluminal studies, urine culture and determination of blood urea and creatinine levels.

On removal of the stent, the presence of urinoma was observed in two animals in group I. There were statistically significant differences between group I and III with regard to evolution of the internal diameter of the UPJ. However, the least severe histological lesion at the UPJ level was found in group II.

Ureteral stent placement for 1 week is insufficient in order to assure correct healing and evolution of the UPJ following endopyelotomy. Stenting for 3 weeks is effective, and it is not necessary to extend stenting time to 6 weeks. Endoluminal ultrasound is of great use in determining the effects of endourological techniques in the ureter and the retroperitoneal space. It is also useful for deciding which therapeutic technique to use, and for inserting the Acucise in order to prevent iatrogenic problems.