Which postoperative findings correlate with failed pyeloplasty?

To evaluate the predicting factors in determining the outcome of pyeloplasty in children with UPJO. In this retrospective study, we analyzed medical records of 47 patients, who underwent pyeloplasty at a single centre in period between 2008 and 2018. Patients without any pre or postoperative diuretic renal scans were excluded from this study. Of 47 patients (48 renal units), 38 patients (39 renal units) had obstructive pattern and 9 patients (9 renal units) had partial obstructive pattern. According to pre and postoperative pattern of diuretic renogram curve, patients were divided into three groups (group 1: improvement of curve pattern, group 2: no change with partial obstructive curve pattern, and group 3: no change with obstructive curve pattern). In all patients, demographics, radiological and intraoperative findings were analyzed, such as a grade of hydronephrosis, APD, parenchymal thickness, and T1/2. Success rate was 89.6% (43/48) and mean follow up period was 67±34 (11-120) months. Mean age of patients at the time of surgery was 41±48 months. Of the 47 patients, 28 (59.6%) underwent left side pyeloplasty, 18 (38.3%) patients had right UPJO and only one (2.1%) patient underwent bilateral surgery. From the overall 48 renal units, group 1, 2 and 3 were 36 (75.0%), 7 (14.6%) and 5 (10.4%), respectively. There was no significant difference of preoperative parameters among 3 groups and between group 1 and 3. In group 3, even though postoperative ultrasound finding was improved, all diuretic renogram finding was worsened. There was no predicting factor of outcome of pyeloplasty in patient with preoperative obstruction curve pattern. However patients with preoperative obstruction curve pattern only showed failure. In case of patient with preoperative obstructive curve, even if they showed a postoperative improvement of ultrasound findings, we have to pay more attention.