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In the Name of the Lord of soul and wisdom

Vesico-ureteral Reflux Alaleh GheissariPediatric NephrologistIUMS

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2

Definition The retrograde flow of urine from

the bladder to the kidneys. VUR:

Primary Isolated

Secondary With CAKUT With Neurogenic Bladder

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Prevalence 1-3% post-mortem 1.3% of healthy children 8-50% of children evaluated for UTI Less severe in African American

than Caucasian

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PrvalenceInfants with prenatal

hydronephrosis: 15% VUR 26% other urogenital anomalies

like duplex systems, UPJ stenosis, urethral valves and mega-ureter.

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Embryology and AnatomySecondary to a pre-existing

anatomic abnormality with shortening of the intra-vesical sub-mucosal length of the ureter.

The length of the sub-mucosal ureter : major component in the prevention

of VUR.

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Embryology If the ureteral bud reaches

the urogenital sinus too early, due to the absorption pattern of the mesonephric duct, it is eventually located more laterally and proximally in the bladder, resulting in VUR.

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Clinical Presentation of Primary VURFollowing diagnostic evaluation of a UTI,

During follow-up for antenatal hydronephrosis,

Screening a sibling of a patient with VUR.

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Presenting Clinical Symptoms of VUR and/or Renal Parenchymal Injury

Fever with or without urinary symptoms

Urinary symptoms without fever

Flank pain

Proteinuria

Nephrotic syndrome due to focal segmentalglomerulosclerosis

Hypertension

Secondary enuresis due to coexisting voiding dysfunctionor diminished urine concentrating ability

Renal stone, mostly due to Proteus mirabilis UTI

Renal failure, including end-stage renal disease

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Voiding Dysfunction and VUR The symptoms of DES

Daytime wetness, Urgency Frequency Infrequency Constipation Faecal incontinence in ‘‘toilet trained’’

children with no underlying anatomic or neurological abnormality

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VUR & Renal ScarringMore than 75% of children

under the age of 5 years with febrile UTI have acute pyelonephritis.

Renal scarring occurs in 10% to 64% of all children with febrile UTI.

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Is VUR dangerous? Bacterial insult:

intrusion of infected urine ( the most common)

Urodynamic insult: abnormal urine pressure exerted by reflux

on the papillae Biochemical insult:

abnormal biochemical or immunological reaction caused by urine

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Pathophysiology of VUR The virulence of bacteriae and their

reservoirs Incompetent vesico-ureteric

junction Renal parenchyma Bladder and bowels dysfunctions. VUR and UTI seem to be

independent pathological factors that may potentiate each other (1).

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Hypertension

Five to 27% of children with renal damage will develop hypertension

Twenty five per cent of ESRD (Italy)can be attributed to VUR related parenchymal anomalies. This rate is evaluated at 5 to 10% in the Australian adult population.

Modern approach of VUR is not accompanied by a reduction of the incidence of VUR-related ESRD.

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Relationship with bladder dysfunctionIn infants: Higher voiding pressures and a

dyssynergic patterns of micturition Predominates in males, May be relevant in the pathogenesis of VUR

and influences its resolution pattern. Different voiding patterns are

reported in infants with dilating VUR when compared with healthy infants.

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Relationship with bladder dysfunction In older children: A strong correlation between bladder

dysfunction, (instability and dyssynergia) and UTI

Together in 60% of cases With VUR in 20% Predominates in female patients Correlate with persistent VUR and UTI,

regardless of surgery An acquired form of VUR of low grade with no

dilatation of the urinary tract.

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When to look for VUR? Prenatal dilatation Fifteen percent: Related to VUR Severe VUR is associated with bilateral

dilatation and congenital renal damage (60%) Predominates in males (75% of all) Lower rates of spontaneous resolution (≤

50%) Significant correlation between antenatal

degree of dilatation and incidence of VUR. Normal prenatal renal sonography does not

exclude VUR.

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When to look for VUR? Febrile urinary tract infection

40% of cases. Siblings

As high as 34%. VUR of low grades (98%) A low risk of renal damage (11%) Asymptomatic in 50% of cases. No prophylaxis is needed.

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When to look for VUR?Other uropathies Dilated upper urinary tracts, Urine flow impairments, Bladder outlet obstruction, Multicystic renal disease, Neuropathic bladder, VUR should be investigated in the 3 first

situations, and discussed in the last 2

clinical presentations.

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How should we look for VUR? Conventional contrast cystography The standard investigation method. Its specificity is high. It gives information about the

anatomy of upper and lower urinary tract.

Its sensitivity is low. The evidence and grade of VUR is not

influenced by timing.

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How should we look for VUR?Nuclear cystography The main pros (comparing with VCUG):

Higher sensitivity (91% versus 45% respectively because of continuous imaging, and its lower radiation exposure.

Fails to give anatomical information about the upper tract, and the urethra in males.

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How should we look for VUR?Nuclear cystography

The most valuable contributions : The evaluation of female patients with normal

ultrasound scans The follow up of VUR managed medically.

Indirect isotopic cystography using Mag 3: Poor records to detect reflux especially in low grades

VUR the advantage to avoid urethral catheterization 15% of false positive VUR is reported making this

technique rather poorly accurate.

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How should we look for VUR? Ultrasonography Low sensitivity No correlation between sonography, and

existence or “severity” of VUR Fifteen percent of prenatal upper urinary

tract dilations are related to VUR. 25% of renal units in children who had

prenatal diagnosis and VUR confirmed postnatally, including “high grade” VUR, are normal on postnatal sonography.

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How should we look for VUR?Ultrasonography The best timing to perform the first postnatal

sonography

Between day 7 to 10, because earlier evaluation usually underestimates the severity of dilatation.

It is appropriate to perform ultrasound scan

earlier in selected cases such as PUV in boys.

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How should we look for VUR?DMSA renal isotopic scan The gold standard study for renal

damage in VUR with a sensitivity of 100% and a specificity of 80%.

DMSA should be performed 6 months after a febrile UTI, since 83% of acute lesions on initial DMSA during acute pyelonephritis improve or disappear.

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How should we look for VUR?Voiding urosonography (VUS)

Using VCUG as the reference,Sensitivity: 57–100%,Specificity: 85–100%Diagnostic accuracy: 78–96%.

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How should we look for VUR? Other common investigations Complications (HTN and RF) should

be systematically assessed: To look for hypertension and tubular damage in

all children presenting with renal lesions. To distinguish dysfunctional from

malformative VUR: Assessment of bladder and intestinal behaviour

history, uroflowmetry, PVR, bladder wall

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How should we look for VUR?Other common investigations Abdominal plain X-ray to

assess: constipation Incidental anomalies (vertebra, stones)

urodynamic studies can be useful especially if a radical treatment of VUR is considered

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How should we look for VUR?Serum Procalcitonin:

High serum procalcitonin seems to be a stong predictor of VUR in children with a first febrile urinary tract infection, with a sensitivity rate of 75% for all-grade VUR, 100% for grade 4 or 5, but with a specificity rate of 43%.

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Should we treat VUR? High rates of spontaneous resolution.

Normal DMSA, normal bladder function and no upper tract dilatation are good predicting factors for spontaneous resolution (100% compared to 30% if kidneys are abnormal on DMSA).

Low grade VUR are mostly associated with bladder dysfunction, while high grade VUR are essentially malformative and more prone to radical treatments.

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How should we treat reflux?Antibioprophylaxis No publication documents that

antibioprophylaxis prevents UTI with or without VUR. The current attitude of giving antibioprophylaxis to all children with VUR is based on the fact that prophylaxis reduces the incidence of renal scars after pyelonephritis.

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How should we treat reflux?Antibioprophylaxis A recent prospective randomized

study shows that antibiotic prophylaxis did not reduce the incidence of UTI in young children with low grade VUR, but it may prevent pyelonephritis in boys with grade III VUR.

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How should we treat reflux? The timing of antibiotic discontinuation: To wait until the age of 7-8 years, To wait until the age of toilet training. To stop antibioprophylaxis in

asymptomatic children after a certain age. A consensus exists on the fact that any symptomatic UTI

should be immediately treated by adequate antibiotics without delay. If the appropriate treatment is postponed, renal damage may occur.

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How should we treat reflux?Surgery: The only advantage of surgery VS medical

significant decrease in the incidence of pyelonephritis,

It does not reduce the number of UTIs neither renal damage (acquired or progressive).

In the hands of experienced surgeons, ureteral reimplantation stops VUR in 98%.

Only in the 10-15% of children not responding to endoscopic treatment and those with severe ureteral anomalies.

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How should we treat reflux? Postoperative morbidity

Ureterovesical obstruction Persistent VUR Transient urine retention, Fluid collections, UTI

Contra lateral VUR appearing after correction of unilateral reflux : 4.6% of cases, but usually resolves with time .

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How should we treat reflux? Take home message: Long-term follow-up studies up to

20 years confirm the ongoing risk of UTI including febrile UTIs (46-52%) as well as the development of hypertension (6%) and renal anomalies (20%) despite successful surgery.

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How should we treat reflux? Cystoscopic subureteral injection “Five years of antibiotics or one

endoscopic injection?”… or no treatment at all! As the best results of injection are found with low grade VUR which tends to resolve with growth and maturation of the bladder in most cases, the question of the indications for injection needs to be addressed.

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How should we treat reflux? Cystoscopic subureteral injection The success rate of endoscopic treatment is

significantly lower, 80.6 to 91% . In addition, there is a potential risk of

migration and toxicity of some “biocompatible” bulking agent used, as well as a risk of ureteral obstruction and recurrence of reflux with this technique.

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