Influence of postnatal hydroureter in determining the need for voiding cystourethrogram in children with high-grade hydronephrosis

Abstract

ObjectiveTo evaluate the utility of hydroureter (HU) to identify high-grade vesico-ureteric reflux (VUR) in patients with high-grade postnatal hydronephrosis (PH).Patients and methodsWe retrospectively reviewed patients’ charts that had antenatal hydronephrosis from 2008 to 2014. Patients were excluded if they presented with febrile urinary tract infection (fUTI), neurogenic bladder, posterior urethral valve, multi-cystic dysplastic kidney, and multiple congenital malformations. We reviewed postnatal ultrasonography images and patients with Society of Fetal Urology (SFU) Grades 3 and 4 hydronephrosis with a renal pelvic antero-posterior diameter of ≥10 mm were included. The ureter was assessed and considered dilated if the ureteric diameter was ≥4 mm. The voiding cystourethrogram (VCUG) studies, fUTI incidence, and surgical reports were reviewed.ResultsOf the 654 patients reviewed, we included 148 patients (164 renal units) of whom 113 (76.4%) were male and 35 (23.6%) female. SFU Grade 3 PH was identified in 49% of the renal units, with the remaining 51% being SFU Grade 4. HU was found in 50/164 renal units and was not detected in the remaining 114 units. VUR was diagnosed in four units (3.5%) without HU (low-grade VUR); whilst it was detected in 19 units (38%) with HU (72.7% were high-grade VUR) (P < 0.001). VUR was diagnosed on the contralateral side in four/105 patients with PH without HU and diagnosed in 10/43 patients with PH with HU (P < 0.001). During a median follow-up of 25.9 months, none of the renal units that had VUR without HU developed UTI or had surgeries.ConclusionLow-grade uncomplicated VUR was diagnosed in 3.5% of renal units without HU. Our results support limiting the use of VCUG to renal units with PH if associated with HU.

Risk of urinary tract infection in patients with hydroureter: An analysis from the Society of Fetal Urology Prenatal Hydronephrosis Registry

“…The increased UTI rate noted in our patients with hydroureteronephrosis is consistent with prior studies on congenital dilated ureter with published UTI rates between 19 and 50% [8,10,12]. PNH with ureteral dilation has been identified previously as an independent risk factor for UTI [6,8,9,18,19]. Similarly, CAP has been shown to be highly protective for patients with PNH and ureteral dilation >11 mm [6].…”

“…A recent prospective study on patients with prenatal hydronephrosis found that patients with non-refluxing primary megaureter (defined as ureteral diameter 7 mm or greater) had almost an 11 times higher risk of UTI [8]. Conversely, Hodhod et al (2018) demonstrated an increased UTI risk in prenatal hydronephrosis patients with hydroureter greater than 4 mm [9].…”

Prenatal hydronephrosis: Bridging pre‐ and postnatal management

“…For low-grade isolated HN (SFU 1-2), the likelihood of VUR was reported to be about 2% and in high grade (SFU 3-4) ranged from 4% to 10%, regardless of whether it was unilateral or bilateral. [47][48][49] In the absence of infections, it is unclear if detecting reflux in these cases changes management dramatically. Conversely, if HN is persistently high grade (SFU 3 or 4), a nuclear renogram with furosemide may be considered after 8 weeks of age, and a pyeloplasty offered if obstruction is suspected.…”

“…In terms of additional imaging, many question the need for a voiding cystourethrogram (VCUG) in this population. For low‐grade isolated HN (SFU 1–2), the likelihood of VUR was reported to be about 2% and in high grade (SFU 3–4) ranged from 4% to 10%, regardless of whether it was unilateral or bilateral 47–49 . In the absence of infections, it is unclear if detecting reflux in these cases changes management dramatically.…”

Comparison of retrograde intrarenal surgery and standard percutaneous nephrolithotomy for management of stones at ureteropelvic junction with high-grade hydronephrosis

“…Ipsilateral hydronephrosis was graded 0 to 4 according to CTU images: grade 0-no caliceal or pelvic dilatation, grade 1-pelvic dilatation only, grade 2-mild caliceal dilatation, grade 3-severe caliceal dilatation and grade 4-caliceal dilatation accompanied by renal parenchymal atrophy. Grade 3 and grade 4 hydronephrosis were defined as high-grade hydronephrosis [6][7][8] .…”