Introduction: Pyeloplasty is the definitive management of ureteropelvic junction obstruction (UPJO). However, one challenging question remains: when to perform pyeloplasty? We studied whether early pyeloplasty, in the first three months of life, could show greater improvement in antenatally diagnosed, postnatally persistent hydronephrosis than surgery at an older age.

Methods: Patients with antenatally detected UPJO who underwent pyeloplasty in the first year of life were retrospectively reviewed. All the patients in this data set had Society of Fetal Urology (SFU) grade 3 or 4 hydronephrosis. Exclusion criteria included patients with single kidneys, bilateral pyeloplasty, and associated other congenital anomalies. Patients were divided into two groups according to the age at pyeloplasty, before or after three months of age. Patient anteroposterior diameter of the renal pelvis (APD), SFU grade, renogram data, and postoperative ultrasound changes were collected and analyzed. The percentage of change of APD (D%APD) was calculated by using the formula: D%APD = [(initial APD/last APD)/initial APD] *100.

Results: Forty-four patients met the inclusion criteria. Thirteen patients had pyeloplasty during the first three months of life and 31 patients at 3–12 months. Results are summarized in Table 1. Most (92%) of those infants who underwent pyeloplasty <3 months of age demonstrated a significant reduction in APD as compared to 80.6% of the older group. Interestingly, D%APD was significantly higher in patients who underwent pyeloplasty in the first three months of life (p=0.04).

Conclusions: Early pyeloplasty, in the first three months of life, showed a significant improvement of APD postoperatively than those who underwent surgery later. It is unclear if this will relate to a reduction of functional renal loss yet bodes well for early intervention.