Summary
Purpose
Hydronephrosis is a common antenatal diagnosis and is present in approximately 1–5%
of pregnancies. The urinary tract dilation (UTD) classification system was introduced
in 2014 and stratifies post-natal hydronephrosis risk into three groups: low-risk
(P1), intermediate-risk (P2), and high-risk (P3). Recommendations for P3 hydronephrosis
have been established, whereas those for P1 and P2 UTD are often left to the discretion
of providers with P1 considered low-grade and less concerning significant pathology.
Given the obscure nature of P2 hydronephrosis, we sought to determine the natural
history and outcomes of pediatric patients with P2 hydronephrosis within a single
institution.
Materials and methods
Children <18 years old diagnosed with hydronephrosis between January 2015 and December
2018 were identified by ICD-9 and ICD-10 codes. Patients with P1 hydronephrosis, P3
hydronephrosis, known vesicoureteral reflux, complex anomalies (ex. Posterior urethral
valve), neurological impairments, neurogenic bladder secondary to spinal abnormalities,
and <6 months of follow-up were excluded. The development of urinary tract infection
(UTI; ≥100 000 CFU/mL of bacterial growth, UA > 10 WBCs/hpf with fever >38C), need
for surgical intervention (impaired renal function, worsening hydronephrosis, and/or
delayed drainage on diuretic renography), and stability of hydronephrosis were collected
retrospectively.
Results
Eighty-seven patients [105 renal units (RU)] were included. Twenty-six patients (30%)
were female and 61 (70%) were male. Of the male patients, 30 (49%) of them were circumcised.
The median age at initial evaluation was 1 month, and the median duration of follow-up
was 13 months. Thirty-four (32%) RU had complete resolution, 24 (23%) improved to
P1 hydronephrosis, 33 (31%) remained stable, and 14 (13%) progressed to P3 hydronephrosis.
The median duration to resolution and improvement was 8.5 months and 5 months, respectively.
Eleven (11%) RU required surgical intervention, 10 of which underwent pyeloplasty,
with a median duration to intervention of 9 months. Fifty-five patients (63%) received
antibiotic prophylaxis (amoxicillin or sulfamethoxazole-trimethoprim) for a median
duration of 5 months. Nine patients (10%) developed a UTI, 3 of which were taking
antibiotic prophylaxis at the time of infection.
Conclusions
Summary Table
| n | 87 |
| Male | 61 (70%) |
| Circumcised | 30 (49%) |
| Uncircumcised | 29 (48%) |
| Female | 26 (30%) |
| Median age at Diagnosis (months) | 1 |
| Median follow up (months) | 13 |
| Prenatal Hydronephrosis | |
| Yes | 69 (80%) |
| No | 18 (21%) |
| Unilateral Hydronephrosis | 69 (80%) |
| Bilateral Hydronephrosis | 18 (21%) |
| Total Renal Units | 105 |
Keywords
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Article info
Publication history
Published online: October 07, 2022
Accepted:
October 6,
2022
Received in revised form:
October 2,
2022
Received:
January 23,
2022
Publication stage
In Press Journal Pre-ProofIdentification
Copyright
© 2022 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
