Summary
Introduction
To evaluate differential renal function (DRF) in unilateral ureteropelvic junction
obstruction (UPJO) patients under 18 years old after pyeloplasty and to identify factors
predicting postoperative improvement.
Material and methods
A total of 95 patients with unilateral UPJO treated by pyeloplasty between March 2019
to March 2020 were prospective enrolled. All patients had preoperative dynamic renal
scintigraphy and were required to review after surgery 6 months. We defined DRF improvement
as postoperative DRF increased ≥5% (If preoperative DRF less than 55%) or postoperative
DRF reduced ≥5% and reached a normal range (45–55%) (preoperative DRF more than 55%)
with drainage improvement. Drainage improvement indications were defined as a resolution
of symptoms; decrease in hydronephrosis without requiring additional procedures and
T1/2＜20min in dynamic renal scintigraphy. All parameters were statistically compared.
Results
In the study, 28 (29.5%) patients showed improvement in postoperative DRF, and 67
(70.5%) patients maintained stable postoperative DRF. Gender, age, baseline DRF, anteroposterior
pelvic diameters (APD), minimum and maximum renal parenchymal thickness (PT), and
anterior-posterior diameter/maximum renal parenchymal thickness (APD/PT) were correlated
with postoperative DRF improvement in univariable analysis. In the multivariable analyses,
maximum PT and APD/PT were predictors of improvement in postoperative DRF.
Discussion
In our study, the maximum PT was associated with the improvement of renal function
in patients with UPJO, and when the thickest part of the renal parenchyma was measured,
APD/PT can predict the improvement of renal function. We infer that the compression
of the thickest part of the renal parenchyma may be the reason for the impaired renal
function in some patients, and when the obstruction was relieved, the compressed parenchyma
function can be significantly improved.
Conclusions
TableCharacteristics and preoperative data of 95 children with UPJO, grouped by improvement
of DRF
| Variable | DRF | χ2/z | p | |
|---|---|---|---|---|
| Improved（n = 28） | No improved (n = 67) | |||
| Gender | ||||
| Male | 26 | 49 | 4.622 | 0.032 |
| Female | 2 | 18 | ||
| Side | ||||
| Left | 22 | 49 | 0.309 | 0.578 |
| Right | 6 | 18 | ||
| Diagnosis time | ||||
| Prenatal | 14 | 32 | 0.040 | 0.842 |
| Postnatal | 14 | 35 | ||
| Age（y） | ||||
| ＜1 | 11 | 11 | 5.803 | 0.016 |
| ≥1 | 17 | 56 | ||
| Surgical approach | ||||
| OP | 11 | 15 | 2.837 | 0.092 |
| LP | 17 | 52 | ||
| Baseline DRF | ||||
| ＜40% | 11 | 12 | 5.739 | 0.044 |
| 40%–55% | 14 | 50 | ||
| ≥55% | 3 | 5 | ||
| APD (cm) | 3.9（2.5，6.1） | 2.8（2.2，3.6） | −2.779 | 0.005 |
| Minimum PT (cm) | 0.2（0.8，0.5） | 0.3（0.2，0.5） | −1.44 | 0.153 |
| Maximum PT (cm) | 0.6（0.4，0.9） | 0.8（0.6，1） | −2.448 | 0.014 |
| APD/PT | 6.8（3.3，12.4） | 3.5（2.3，5.3） | −2.977 | 0.003 |
Keywords
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Article info
Publication history
Published online: June 19, 2022
Accepted:
June 15,
2022
Received in revised form:
June 8,
2022
Received:
February 15,
2022
Identification
Copyright
© 2022 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
