Sonographic follow-up after pyeloplasty: a large, retrospective cohort analysis

Routine scintigraphy after surgery for uretero-pelvic junction obstruction (UPJO) is discouraged, making ultrasound the preferred option for follow up. Yet, interpretation of sonographic parameters is rarely straightforward.

We reviewed 111 cases including 97 pyeloplasty (52 open, 45 laparoscopic) and 14 pyelopexy during a 7-year period. Pre- and postoperative pelvic antero-posterior diameter (APD), cortical thickness (CT) and pelvis/cortex ratio (PCR) was measured serially.

85% were free of symptoms by 1 year. Only 11% had complete resolution of hydronephrosis. Eleven (10.4%) needed a redo procedure. Mean reduction in APD was 32.6%, 45.8%, and 51.7% at 6 weeks, 3 and 6 months respectively. CT increased by an average 55.9%, 75.6% and 107.6% while PCR reduced by 6.9, 8.0 and 8.8 at given intervals. Comparison of open and laparoscopic procedures showed no significant difference. Review of failed pyeloplasty showed failure of reduction in APD (APD > 3 cm or < 25% reduction) and PCR (PCR > 4) as early indicators for failure.

Both APD and PCR are reliable indicators of success and failure following pyeloplasty while CT alone is not as useful. Laparoscopic procedures are non-inferior to standard open surgery.