Reliability and validity of endoluminal sonography in a porcine model of ureteropelvic junction obstruction.

PURPOSE

The objective of this study was to evaluate the usefulness and reliability of endoluminal ultrasonography in ureteropelvic junction (UPJ) obstruction and to describe the changes in sonographic appearance that take place during obstruction and after treatment.

MATERIALS AND METHODS

Twelve large healthy white female pigs were randomly divided into two groups: Group 1 (laparoscopic pyeloplasty) and group 2 (cutting balloon endopyelotomy). Percutaneous and endoluminal ultrasonographic and fluoroscopic studies were analyzed during the three phases of the study. The first phase included premodel documentation of a normal urinary tract and laparoscopic UPJ obstruction. During the second phase 6 weeks later, diagnosis and endourologic treatment were performed. Fifteen weeks after obstruction management, follow-up imaging studies and postmortem evaluation of all animals were performed.

RESULTS

At the end of the study, group 1 had a lesser degree of fibrosis in the muscle-adventitia layers and periureteral repercussion, as well as a better peristaltic recovery. The animal study shows a positive correlation among the results of the pathologic and the endoluminal ultrasonographic studies in UPJ obstruction.

CONCLUSIONS

Endoluminal ultrasonography provides excellent information regarding ureteral and periureteral anatomy. Among the two techniques evaluated in the study, laparoscopic pyeloplasty caused the lesser reaction at the reconstructed area. Fibrous replacement at the muscle-adventitia layers and periureteral area may be useful as indicators of the better therapeutic technique as well as for the assessment of post-therapeutic ureteral evolution and recurrences.