Vesicoureteral Reflux: Symptoms, Types, Causes and Treatment

Vesicoureteral reflux (VUR) is a urological condition that affects both children and adults, but is most commonly diagnosed in the pediatric population. At its core, VUR involves the abnormal backward flow of urine from the bladder up toward the kidneys. This seemingly simple deviation from normal urinary tract function can have complex consequences, including an increased risk of urinary tract infections (UTIs) and, in severe cases, lasting kidney damage. Understanding the symptoms, types, underlying causes, and treatment options for VUR is essential for patients, caregivers, and healthcare professionals alike.

Symptoms of Vesicoureteral Reflux

Recognizing the symptoms of vesicoureteral reflux is a critical first step in timely diagnosis and management. While some individuals remain asymptomatic, others may experience symptoms that bring them to medical attention, especially after a urinary tract infection.

Symptom	Description	Patient Group	Source(s)
UTI	Frequent or recurrent urinary infections	Mostly children	1 7 8 11
Fever	Often with UTI, may indicate pyelonephritis	Children	3 8 11
Flank/abdominal pain	Pain in sides or abdomen, sometimes with urination	Children/adults	1 3 7 8
Asymptomatic	No symptoms; found during UTI evaluation	All ages	7 8
Bowel/Bladder Dysfunction	Urinary frequency, urgency, wetting, constipation	Children	1 11

Table 1: Key Symptoms

Understanding the Symptoms

Urinary Tract Infections (UTIs)

• The most common presenting symptom of VUR, especially in children, is a urinary tract infection.
• Up to 30% of children with a UTI are found to have VUR after appropriate imaging 7 8.
• These infections can be recurrent, sometimes accompanied by fever, which signals the possibility of kidney involvement (pyelonephritis) 3 8 11.

Fever and Pain

• Febrile UTIs are particularly concerning, as they raise the risk of kidney scarring 3 8 11.
• Children may report flank or abdominal pain during infections, which should prompt further investigation.

Bladder and Bowel Dysfunction (BBD)

• Many children with VUR also exhibit symptoms of bladder and bowel dysfunction, such as urinary urgency, frequent urination, daytime wetting, constipation, and even encopresis (fecal incontinence) 1 11.
• BBD increases the risk of recurrent infections and can complicate treatment 1.

Asymptomatic Cases

• Not all cases of VUR present with clear symptoms. Sometimes VUR is discovered during the evaluation of a sibling of a known patient or incidentally during imaging for other reasons 7 8.

Types of Vesicoureteral Reflux

Vesicoureteral reflux is not a one-size-fits-all diagnosis. It is classified based on its origin, severity, and laterality, each of which influences management strategies and outcomes.

Type	Defining Feature	Typical Patient	Source(s)
Primary VUR	Congenital abnormality at UVJ	Infants/children	2 4 5 7 8
Secondary VUR	Result of high bladder pressure/obstruction	Children/adults	2 8 11
Grading	I (mild) - V (severe)	All ages	3 8 11
Laterality	Unilateral or bilateral	All ages	8 9

Table 2: Classification of VUR

Breaking Down the Types

Primary Vesicoureteral Reflux

• Results from a congenital defect at the ureterovesical junction (UVJ), often due to a short submucosal tunnel in the bladder wall 2 4 5.
• Most common in infants and young children.
• Frequently associated with genetic factors and congenital anomalies of the urinary tract 4 5 7.

Secondary Vesicoureteral Reflux

• Occurs due to increased pressure within the bladder, often from bladder outlet obstruction, neurogenic bladder, or dysfunctional voiding 2 8 11.
• Can develop at any age but is often linked to underlying urological or neurological conditions.
• Proper identification of the underlying cause is crucial before considering surgical intervention 2.

Grading of VUR

• VUR is graded I through V based on imaging (voiding cystourethrogram), with higher grades indicating more severe reflux and greater risk of renal damage 3 8 11:
  • Grade I: Reflux into ureter only
  • Grade II: Reflux reaches renal pelvis, no dilation
  • Grade III: Mild to moderate dilation
  • Grade IV: Moderate dilation and tortuosity
  • Grade V: Gross dilation, loss of papillary impressions

Laterality

• VUR can be unilateral (affecting one ureter) or bilateral (both ureters), with bilateral cases carrying a higher risk for renal scarring 8 9.

Causes of Vesicoureteral Reflux

Understanding why VUR occurs is key to both prevention and effective treatment. The causes are complex, involving a mix of genetic, anatomical, and functional factors.

Cause	Description	Association	Source(s)
Genetic factors	Family history, specific gene mutations	Primary VUR	4 5 7 8
Anatomic defect	Short ureteral tunnel at bladder entry	Congenital/Primary VUR	2 4 5 7
Dysfunctional voiding	Abnormal bladder/bowel function	Increases VUR risk	1 2 3 8 11
Bladder outlet obstruction	Blockage or elevated pressure	Secondary VUR	2 6 8 11
Infection-induced	Damage from recurrent UTIs	Renal scarring	3 8

Table 3: Underlying Causes of VUR

Exploring the Causes

Genetic and Developmental Factors

• VUR often runs in families, suggesting a genetic predisposition 4 5 7 8.
• Studies have identified trends toward association with genes involved in ureteric budding, such as GREM1, EYA1, and TNXB 4 5.
• VUR is part of the broader spectrum of congenital anomalies of the kidney and urinary tract (CAKUT) 4.

Anatomical Abnormalities

• The classical cause of primary VUR is a short or malpositioned intravesical ureter, which fails to prevent backflow of urine during bladder contraction 2 4 5 7.
• This defect is present from birth and may be detected in utero or soon after birth.

Bladder and Bowel Dysfunction (BBD)

• BBD increases the risk of developing VUR and complicates its management 1 3 8 11.
• Symptoms such as infrequent voiding, constipation, and posturing to avoid wetting are common in affected children 1.

Bladder Outlet Obstruction and Secondary Causes

• Secondary VUR arises from increased bladder pressure due to obstruction, neurogenic bladder, or dysfunctional elimination 2 6 8 11.
• Identifying and treating the obstruction is vital before attempting surgical correction 2.

Infection and Renal Scarring

• Recurrent UTIs, especially those that ascend to the kidneys (pyelonephritis), can cause or exacerbate VUR and lead to renal scarring 3 8.
• However, low-pressure, sterile reflux typically does not cause kidney damage 3.

Treatment of Vesicoureteral Reflux

The goal of VUR treatment is to prevent kidney damage by minimizing recurrent UTIs and controlling reflux. Management is highly individualized, considering patient risk factors, reflux severity, and presence of complications.

Treatment	Description	Indications	Source(s)
Observation	Monitoring, often for mild or low-grade VUR	Low-risk, likely to resolve	7 8 11 12
Antibiotic Prophylaxis	Low-dose antibiotics to prevent UTI	Recurrent UTI, waiting for resolution	8 11 12
Bladder/Bowel Rehab	Treats underlying voiding dysfunction	BBD, coexisting LUTD	1 8 11
Endoscopic Injection	Bulking agent injected at UVJ	Persistent VUR, failed conservative tx	9 10 12
Surgery (Reimplantation)	Open, laparoscopic, or robot-assisted	High-grade, failed other tx	8 11 12

Table 4: Major Treatment Options

Navigating the Treatment Landscape

Observation and Watchful Waiting

• Many children, especially those with low-grade VUR, will experience spontaneous resolution as they grow 7 8.
• Close monitoring with regular imaging and prompt treatment of any UTIs is key.

Antibiotic Prophylaxis

• Continuous low-dose antibiotics are used to prevent recurrent UTIs while waiting for possible resolution 8 11 12.
• Recent studies show mixed evidence on its effectiveness, but it is still a mainstay for selected patients 11.

Bladder and Bowel Rehabilitation

• Addressing BBD through behavioral modification, timed voiding, biofeedback, and treatment of constipation can reduce VUR severity and infection risk 1 8 11.
• Individualized approaches are essential, and adjunct medications (anticholinergics, α-blockers) may be used in select cases 1.

Endoscopic Injection

• Involves injecting a bulking agent (such as dextranomer/hyaluronic acid) at the UVJ to prevent reflux 9 10 12.
• Advantages include being minimally invasive, with success rates comparable to surgery for many patients 10 12.
• The hydrodistension implantation technique (HIT) may offer higher success than the traditional STING method 10.

Surgical Correction

• Ureteral reimplantation (open, laparoscopic, or robotic) is reserved for high-grade VUR or when other measures fail 8 11 12.
• Surgical approaches are increasingly minimally invasive, with high success rates and low morbidity 11 12.
• Individualization based on patient risk, anatomy, and previous treatments is key to optimal outcomes 11.

Conclusion

Vesicoureteral reflux is a complex and variable condition, but modern understanding has provided a wealth of options for diagnosis and management. Early recognition and risk stratification are critical for protecting kidney health and minimizing long-term complications.

Key Takeaways:

• Symptoms: Most often presents with recurrent UTIs, but may be asymptomatic or associated with bladder and bowel dysfunction.
• Types: Divided into primary (congenital) and secondary (acquired), with severity graded I-V and classified as unilateral or bilateral.
• Causes: Include genetic predisposition, anatomical defects, bladder/bowel dysfunction, and, less commonly, infection-related factors.
• Treatment: Ranges from observation and antibiotic prophylaxis to minimally invasive endoscopic therapy and surgical reimplantation; individualized care and addressing underlying dysfunctions are crucial.

By staying informed and engaging in shared decision-making with healthcare providers, families can navigate the challenges of VUR and ensure the best possible outcomes for affected children and adults.