Overview
Definition:
Vesicoureteral reflux (VUR) is the retrograde flow of urine from the bladder back up into the ureters or renal pelvis
It is a significant risk factor for recurrent urinary tract infections (UTIs) and potential renal scarring, especially in infants and children
The International Classification of VUR (ICVVUR) is used to grade its severity.
Epidemiology:
VUR is the most common congenital abnormality of the pediatric urinary tract, occurring in 5-30% of children with UTIs
Primary VUR, due to anatomical abnormalities at the ureterovesical junction, accounts for the majority of cases
Secondary VUR can be caused by bladder outlet obstruction or neurogenic bladder
Its prevalence is higher in neonates and infants, decreasing with age.
Clinical Significance:
VUR is critical to identify as it predisposes children to recurrent UTIs, which can lead to pyelonephritis and chronic kidney disease (CKD) due to renal parenchymal damage and scarring
Early diagnosis and appropriate management, including prophylaxis, are essential to prevent long-term renal damage and preserve kidney function.
Clinical Presentation
Symptoms:
In infants and young children: Fever
Irritability
Poor feeding
Vomiting
Failure to thrive
In older children: Classic UTI symptoms such as dysuria, frequency, urgency, suprapubic pain
Flank pain or costovertebral angle tenderness suggestive of pyelonephritis
Recurrent febrile UTIs are a major red flag.
Signs:
Fever
Abdominal tenderness
Costovertebral angle tenderness
In severe cases or with complications: Hypertension, edema, failure to thrive.
Diagnostic Criteria:
Diagnosis of VUR is confirmed by imaging studies that visualize retrograde flow
Definitive diagnosis typically requires a voiding cystourethrogram (VCUG)
Renal ultrasound is often the initial imaging modality to assess for hydronephrosis or renal parenchymal abnormalities, but it does not diagnose VUR.
Diagnostic Approach
History Taking:
Detailed history of previous UTIs, including documented culture results and fever
Family history of VUR or renal anomalies
Age at first UTI
Symptoms suggestive of dysfunctional voiding
Any history of abdominal masses or urinary obstruction
Red flags: recurrent febrile UTIs, UTIs in infants, family history, abnormal physical findings.
Physical Examination:
General assessment: growth parameters, hydration status
Abdominal examination: palpation for bladder distension or masses
Genitourinary examination: assess for external anomalies, meatal stenosis, or suspected urethral abnormalities
Palpate flanks for tenderness.
Investigations:
Urinalysis and urine culture: essential for diagnosing UTI
Renal and bladder ultrasound: identifies hydronephrosis, renal parenchymal abnormalities (scarring), bladder wall thickening, or stones
Voiding Cystourethrogram (VCUG): the gold standard for VUR diagnosis, grading, and assessing reflux pattern
Dimercaptosuccinic acid (DMSA) renal scan: assesses for pyelonephritis and quantifies renal scarring, useful for determining renal parenchymal damage, particularly after a febrile UTI
However, it does not diagnose VUR itself.
Differential Diagnosis:
Other causes of recurrent febrile episodes in infants
Dysfunctional voiding
Congenital urinary tract anomalies not associated with VUR
Meatal stenosis
Urethral abnormalities
Bladder exstrophy.
Vur Grading And Management
Vur Grading Icvvur:
The International Classification of Vesicoureteral Reflux (ICVVUR) grades VUR from I to V based on VCUG findings: Grade I: Reflux into ureter only
Grade II: Reflux into ureter and renal pelvis without dilation
Grade III: Reflux with mild/moderate ureteral tortuosity and mild calyceal dilation
Grade IV: Reflux with marked ureteral tortuosity and moderate renal pelvic/calyceal dilation
Grade V: Gross reflux with severe ureteral dilation, tortuosity, and calyceal dilation
no normal fornices.
Management Philosophy:
Management depends on VUR grade, presence of UTI, renal scarring, patient age, and family compliance
Goals are to prevent UTI, prevent renal scarring, and preserve renal function
Management options include observation, medical management (antibiotic prophylaxis), and surgical correction.
Observation:
Suitable for low-grade VUR (Grades I-II), especially in older children where spontaneous resolution is likely
Requires vigilant monitoring for UTIs and regular follow-up.
Medical Management Prophylaxis:
Antibiotic prophylaxis is given to prevent UTIs
Common agents include trimethoprim-sulfamethoxazole (TMP-SMX) or nitrofurantoin
Dosing is typically low (e.g., TMP-SMX 2 mg/kg/day once daily
Nitrofurantoin 1-2 mg/kg/day once daily)
Prophylaxis is usually continued until VUR resolves or the child is post-pubertal and has no recurrent UTIs
Consideration for bowel and bladder dysfunction (BBD) management is crucial in older children with VUR.
Surgical Management:
Indicated for high-grade VUR (Grades IV-V), recurrent febrile UTIs despite prophylaxis, progressive renal scarring, or significant renal obstruction
Surgical techniques aim to create a competent ureterovesical junction, such as the Lich-Gregoir ureteral reimplantation (extravesical approach) or the Cohen procedure (intravesical approach)
Endoscopic injection of bulking agents (e.g., dextranomer/hyaluronic acid) is also an option for selected cases of low to moderate grade VUR.
Prophylaxis In Recurrent Utis:
For recurrent UTIs without confirmed VUR, prophylaxis may be considered based on frequency and severity of infections
Continuous low-dose prophylaxis or post-coital prophylaxis may be used
Investigations for underlying causes of recurrent UTIs, such as BBD or anatomical abnormalities, are essential
The decision for prophylaxis should be individualized.
Complications
Early Complications:
Acute pyelonephritis
Sepsis
Antibiotic resistance with prolonged prophylaxis.
Late Complications:
Renal scarring
Hypertension
Chronic kidney disease (CKD)
End-stage renal disease (ESRD) in severe cases
Dilated cardiomyopathy due to chronic hypertension.
Prevention Strategies:
Prompt diagnosis and treatment of UTIs
Appropriate VUR grading and management
Effective antibiotic prophylaxis when indicated
Management of dysfunctional voiding
Surgical correction for high-grade or persistent VUR
Regular follow-up and monitoring of renal function and blood pressure.
Prognosis
Factors Affecting Prognosis:
Grade of VUR
Presence and extent of renal scarring
Age at diagnosis
Recurrence of UTIs
Compliance with medical management
Effectiveness of surgical correction
Development of hypertension or CKD.
Outcomes:
With appropriate management, most children with low-grade VUR have an excellent prognosis and achieve spontaneous resolution
High-grade VUR or significant scarring may lead to long-term renal issues
Early and effective intervention is key to preserving renal function.
Follow Up:
Regular follow-up with a pediatric nephrologist or urologist is crucial
This includes periodic urine cultures, renal ultrasounds, and potentially DMSA scans or VCUGs to monitor VUR resolution and assess for new scarring
Blood pressure monitoring is essential, especially in children with identified scarring or hypertension.
Key Points
Exam Focus:
DNB/NEET SS often test knowledge of VUR grading (ICVVUR), indications for prophylaxis, choice of prophylactic agents (TMP-SMX, Nitrofurantoin), management of recurrent UTIs, and indications for surgical intervention
Understanding the roles of VCUG and DMSA scans is vital
Recognize dysfunctional voiding as a common contributing factor in older children.
Clinical Pearls:
Always consider VUR in infants with a first febrile UTI, especially boys
Recurrent UTIs in any child warrant investigation for VUR or dysfunctional voiding
DMSA scan is better than ultrasound for detecting established renal scarring
Spontaneous resolution of VUR is common in low grades but requires diligent follow-up.
Common Mistakes:
Underestimating the importance of recurrent UTIs in children
Failing to investigate for VUR or dysfunctional voiding
Relying solely on renal ultrasound to rule out VUR
Inappropriate antibiotic prophylaxis duration or dosage
Delaying surgical intervention in high-grade VUR with recurrent infections.