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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References
- Early pyeloplasty versus conservative management of severe ureteropelvic junction obstruction in asymptomatic infants.J Pediatr Surg. 2020; 55: 1936-1940https://doi.org/10.1016/j.jpedsurg.2019.08.006
- Changes in differential renal function after pyeloplasty in infants and children.J Pediatr Urol. 2020; 16: 329.e1-329.e8https://doi.org/10.1016/j.jpurol.2020.02.002
- Functional and morphological outcomes of pyeloplasty at different ages in prenatally diagnosed society of fetal urology grades 3-4 ureteropelvic junction obstruction: is it safe to wait?.Urology. 2017; 101: 45-49https://doi.org/10.1016/j.urology.2016.10.004
- Changes in differential renal function after pyeloplasty in children.J Urol. 2013; 190: 1468-1473https://doi.org/10.1016/j.juro.2013.01.004
- Pyeloplasty is a safe and effective surgical approach for low functioning kidneys with ureteropelvic junction obstruction.J Pediatr Urol. 2021; 17: 233.e1-233.e7https://doi.org/10.1016/j.jpurol.2020.12.018
- Comparative outcome analysis of children who underwent pyeloplasty for ureteropelvic junction obstruction associated with or without supranormal differential renal function.Urology. 2017; 99: 210-214https://doi.org/10.1016/j.urology.2016.07.016
- Value of supranormal function on Tc-mercaptoacetyltriglycine renal scan in paediatric patients with obstructive hydronephrosis.BJU Int. 2019; 124: 842-848https://doi.org/10.1111/bju.14781
- Guidelines for standard and diuretic renogram in children.Eur J Nucl Med Mol Imag. 2011; 38: 1175-1188https://doi.org/10.1007/s00259-011-1811-3
- Early postoperative ultrasound after open pyeloplasty in children with prenatal hydronephrosis helps identify low risk of recurrent obstruction.J Urol. 2012; 188: 2347-2353https://doi.org/10.1016/j.juro.2012.08.036
- Percent improvement in renal pelvis antero-posterior diameter (PI-APD): prospective validation and further exploration of cut-off values that predict success after pediatric pyeloplasty supporting safe monitoring with ultrasound alone.J Pediatr Urol. 2016; 12 (228.e1-6)https://doi.org/10.1016/j.jpurol.2016.04.003
- Factors predicting improvement of renal function after pyeloplasty in pediatric patients: a prospective study.J Urol. 2012; 188: 262-265https://doi.org/10.1016/j.juro.2012.03.023
- The long-term results of Anderson-Hynes pyeloplasty.BJU Int. 2001; 87: 287-289https://doi.org/10.1046/j.1464-410x.2001.00108.x
- Functional outcome after pyeloplasty for unilateral symptomatic hydronephrosis.Pediatr Surg Int. 2001; 17: 524-527https://doi.org/10.1007/s003830100604
- Unilateral ureteropelvic junction obstruction in children: long-term followup after unilateral pyeloplasty.J Urol. 2003; 170 (discussion 579): 575-579https://doi.org/10.1097/01.ju.0000071480.83890.36
- Postnatal unilateral pelviureteral junction obstruction: impact of pyeloplasty and conservative management on renal function.Urology. 2005; 65 (discussion 985): 980-985https://doi.org/10.1016/j.urology.2004.12.065
- Functional outcomes of early versus delayed pyeloplasty in prenatally diagnosed pelvi-ureteric junction obstruction.J Pediatr Urol. 2015; 11https://doi.org/10.1016/j.jpurol.2014.10.007
- Grading of hydronephrosis: an ongoing challenge.Frontiers in pediatrics. 2020; 8: 458https://doi.org/10.3389/fped.2020.00458
- Correlation of renal histopathology with sonographic findings.Kidney Int. 2005; 67: 1515-1520https://doi.org/10.1111/j.1523-1755.2005.00230.x
- Ultrasound grade of hydronephrosis and severity of renal cortical damage on 99m technetium dimercaptosuccinic acid renal scan in infants with unilateral hydronephrosis during followup and after pyeloplasty.J Urol. 2002; 167: 2159-2163https://doi.org/10.1097/00005392-200205000-00061
- Pelviureteral junction obstruction: correlation of renal cell apoptosis and differential renal function.J Urol. 2003; 169: 2335-2338https://doi.org/10.1097/01.ju.0000067385.26560.7c
- An initial differential renal function between 35% and 40% has greater probability of leading to normal after pyeloplasty in patients with unilateral pelvic-ureteric junction obstruction.Int Urol Nephrol. 2017; 49: 1701-1706https://doi.org/10.1007/s11255-017-1665-0
- Management of ureteropelvic junction obstruction in infants.J Urol. 1983; 129: 108-110https://doi.org/10.1016/s0022-5347(17)51945-x
- Management of ureteropelvic junction obstruction in children-a roundtable discussion.J Pediatr Urol. 2019; 15: 322-329https://doi.org/10.1016/j.jpurol.2019.05.010
- The importance of obtaining conjugate views on renographic evaluation of large hydronephrotic kidneys: an in vitro and ex vivo analysis.J Urol. 2008; 180: 1559-1565https://doi.org/10.1016/j.juro.2008.06.010
- Letter to the editor regarding ‘changes in differential renal function after pyeloplasty in infants and children’ by Josefin Nordenström, Giasemi Koutozi, Gundela Holmdahl, kate Abrahamsson, Rune Sixt, Sofia Sjöström.J Pediatr Urol. 2020; 16: 740-741https://doi.org/10.1016/j.jpurol.2020.07.033
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.
