Summary
Introduction
Indications for treatment of ureteropelvic junction obstruction (UPJO) include symptomatic
obstruction, urinary tract infections, presence of an obstructive pattern on functional
renal scan and/or worsening differential renal function (DRF). This paper aims to
determine the relationship between preoperative DRF and surgical outcomes after pyeloplasty.
We hypothesized that low preoperative DRF is not an independent predictor of pyeloplasty
failure.
Methods
A retrospective chart review was performed to identify all patients undergoing pyeloplasty
for UPJO between 2008 and 2019. Patients were included only if they had at least one
preoperative functional scan and a minimum of one renal ultrasound post-operatively.
Patients were divided into three groups based on DRF for analysis: Group 1- 0-10%,
Group 2 - >10-≤20%, Group 3 - >20%. Baseline, intraoperative and postoperative characteristics,
including success and complications were compared. Additional sensitivity analyses
were performed comparing patients with ≤20%, and >20% function, ≤30%, and >30% function
as well as an analysis of patients undergoing only minimally invasive reconstruction.
Results
Three hundred and sixty-four patients met inclusion criteria. We identified 8 patients
in Group 1, 24 patients in Group 2 and 332 patients in Group 3. Mean procedure time
was longest for the ≤10% function group (237.9 vs 206.4 vs 189.1; p = 0.01). We found
no difference in 30-day post-operative complications, overall success rate or the
need for additional procedures among the three groups. For patients in Group 1, we
noted variation in the post-procedure DRF with a range of −2.8 to +47% change. In
this group, none of patients with low DRF underwent nephrectomy. Multivariate logistic
regression did not identify renal function as a predictor of operative success OR
1.00 (95% CI: 0.97–1.03) (p-value: 0.88).
Discussion
The results of the present study suggest that low DRF alone is not associated with
worse outcomes and shows no difference in the failure rate. The incidence and type
of complications were not increased for the lower functioning groups. The main limitation
of this study would be its retrospective nature and single-institution experience.
Furthermore, post-operative functional studies were not available for all patients,
limiting the ability to draw conclusions on the change in DRF after surgery.
Conclusions
Summary TableSurgical outcomes after pyeloplasty categorized by baseline renal function.
| Factor, N (%) | Preoperative renal function | p-value | ||
|---|---|---|---|---|
| Group 1 0-10% | Group 2 >10% - ≤20% | Group 3 >20% | ||
| N | 8 | 24 | 332 | |
| Technique | 0.40 | |||
| Robotic-Assisted | 8 (100.0%) | 19 (79.2%) | 256 (77.1%) | |
| Open | 0 (0.0%) | 4 (16.7%) | 70 (21.1%) | |
| Laparoscopic | 0 (0.0%) | 1 (4.2%) | 6 (1.8%) | |
| Post-operative Complications | 1 (12.5%) | 4 (16.7%) | 51 (15.4%) | 0.91 |
| Grade 1 | 0 (0.0%) | 2 (50.0%) | 13 (25.5%) | 0.75 |
| Grade 2 | 1 (100.0%) | 2 (50.0%) | 23 (45.1%) | |
| Grade 3a | 0 (0.0%) | 0 (0.0%) | 1 (2.0%) | |
| Grade 3b | 0 (0.0%) | 0 (0.0%) | 13 (25.5%) | |
| Grade 4a | 0 (0.0%) | 0 (0.0%) | 1 (2.0%) | |
| Overall success | 8 (100.0%) | 23 (95.8%) | 311 (93.7%) | 1.00 |
| Asymptomatic after surgery | 8 (100%) | 23 (95.8%) | 314 (94.6%) | 1.00 |
| Unimproved hydronephrosis | 0 (0.0%) | 1 (0%) | 21 (6.3%) | 0.72 |
| Additional endoscopic procedure | 0 (0.0%) | 1 (4.2%) | 19 (5.7%) | 1.00 |
| Underwent redo reconstruction | 0 (0.0%) | 1 (4.2%) | 12 (4.2%) | 1.00 |
Keywords
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Article info
Publication history
Published online: December 19, 2020
Accepted:
December 17,
2020
Received in revised form:
December 10,
2020
Received:
September 23,
2020
Identification
Copyright
© 2020 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
