Renal Hemodynamic Changes and Postsurgical Recovery in Children Treated for Ureteropelvic Junction Obstruction.

Objective The aims of the study were to measure renal hemodynamic indexes and to evaluate postsurgical recovery in children diagnosed with obstructive hydronephrosis using color Doppler ultrasound. Methods This study enrolled 36 patients with ureteropelvic junction obstruction who underwent Anderson-Hynes pyeloplasty. The peak systolic velocity (PSV) and the resistive index (RI) of the main renal arteries (MRAs) and interlobar renal arteries (IRAs) were measured using color Doppler ultrasound. Renal hemodynamic indexes were measured before surgery and 2, 4, 6, 8, 10, 12, 14, and 16 weeks after surgery. Results Split renal function and renal parenchymal thickness were positively correlated with PSV and negatively correlated with RI. Anterior-posterior diameter had no significant correlation with PSV or RI. The PSV in MRAs and IRAs were lower than those of the contralateral kidneys but increased after surgery. Anderson-Hynes pyeloplasty was successfully performed in all patients, including one patient whose kidney was removed 16 weeks after surgery. The RI in the MRAs and IRAs were higher than those of the contralateral kidneys but decreased within 2 weeks after surgery. Peak systolic velocity and RI were still atypical 16 weeks after surgery. The hemodynamic index of the nonfunctional kidney did not show improvement after surgery. Conclusions Peak systolic velocity and RI were correlated with renal function and renal parenchymal thickness but were not correlated with dilatation of the renal pelvis. Peak systolic velocity increased whereas RI decreased after surgery and were stable at 8 weeks, but remained abnormal 16 weeks after surgery. Hemodynamic measurements may be a useful and convenient method to evaluate surgical outcomes after Anderson-Hynes pyeloplasty.