Outcome Analysis of Reduction and Nonreduction Dismembered Pyeloplasty in Ureteropelvic Junction Obstruction: a Large, Multicenter, Retrospective, Comparative Study.

OBJECTIVE

To evaluate whether renal pelvis reduction improves outcomes in pediatric pyeloplasty, comparing open and robotic-assisted laparoscopic pyeloplasty (RALP).

METHODS

We conducted a multicenter retrospective cohort study at three tertiary centers (2006-2024). Records of children undergoing open pyeloplasty or RALP for UPJO were reviewed. Cases were classified as reduction (RP) or nonreduction pyeloplasty (NRP). Demographics, perioperative data, and follow-up imaging were extracted. Surgical success was the primary endpoint. Secondary endpoints were operative time, SFU grade, APD, SRF, and 12-month complications (Clavien-Dindo). Predictors of failure were examined with multivariate logistic regression.

RESULTS

Of 450 renal units, 34% underwent open surgery and 66% RALP. PR was performed in 98.6% of open cases but only 9.9% of RALP cases (167 RP, 283 nonreduction pyeloplasty). Redo pyeloplasty was uncommon and similar (6.6% RP vs 5.5% nonreduction pyeloplasty, p = .68). RP appeared faster overall (78 min vs 120 min, p < .001), likely due to the reduction coinciding with inherently quicker open procedures. Post-operative SFU grade (median 2), APD (14.8 mm RP vs 14.0 mm nonreduction pyeloplasty, p = .40), SRF (47% vs 46%, p = .68), and complication rates (24.0% vs 22.9%, p = .82) were equivalent. PR was not a predictor of failure, whereas open surgery independently predicted redo (OR 13.4, 95% CI 1.03-173.0, p = .047).

CONCLUSION

Routine renal-pelvis reduction provides no functional or radiologic benefit in either open or robotic pediatric pyeloplasty. Except in rare scenarios such as giant hydronephrosis, omission may avoid unnecessary suturing and, in RALP, shorten operative time.