Vesico-Ureteric Reflux

The retrograde flow of urine from the urinary bladder into the ureter and Kidneys either during micturition or at rest is called Vesico-Ureteric Reflux. Vesico-Ureteric Refux is the most common cause of recurrent urinary tract infections in children. 

Types of Vesico-Ureteric Reflux

Primary Vesico-Ureteric Reflux

Vesico-Ureteric Reflux is associated with primary problems at the Vesico-Ureteric junction. There are two types of primary problems at Vesico- Ureteric junction:

• Isolated primary Vesico-Ureteric Reflux
  • Genetic basis and 
  • Autosomal dominant inheritance: incomplete penetrance.
• Other types of Primary Vesico-Ureteric Reflux associated with Vesico-Ureteric anomalies include:
  • Vesico-Ureteric Reflux associated with Ureteral duplication.
  • Vesico-ureteric reflux associated with ureterocoele.
  • Vesico-ureteric reflux associated with Diverticula.

Secondary Vesico-Ureteric Reflux

• Vesico-ureteric reflux is associated with problems in the remaining lower urinary tract, such as the bladder, ureter, etc.
• Most commonly occurs –
  • Bladder outlet obstruction, e.g., PUV (50% of the cases).
• Neurogenic or neuropathic bladder, e.g., Meningomyelocele (25% of the cases).
• Renal stones 
• Bladder stones 
• Surgery 
• Urethral anomalies 

Epidemiology of Vesico Ureteric Reflux (VUR)

• Affects 1 to 2% of children overall.
• About 30% of urinary tract infections, especially in females, have an associated VUR. 
• About 15% of infants with antenatal hydronephrosis have VUR. 
• Children with VUR and UTI have three times more risk of renal injury than UTIs without VUR. 
• About 20 to 40% of children with VUR and UTI develop renal scarring, and 10% can progress to ESRD. 

Pathophysiology of Vesico Ureteric Reflux (VUR)

In a normal person, the Wall of the urinary bladder, the submucosa, the mucosal layer, and the cavity of the urinary bladder. The ureter opens at an angle into the wall and forms an oblique tunnel in the urinary bladder, and another tunnel is formed in the sub-mucosa by changing the tangle. The tunnel then opens into the mucosa.

In a patient with Vesicoureteric reflux, there is a combination of three mechanisms. When a person passes urine, the reflex through the long angulated submucosal tunnel is difficult. The intramural part gets compressed, making the lumen narrow. The oblique opening of the ureter creates a flap valve mechanism and prevents the VUR from happening.

We can understand here that the Basis of primary VUR is an Oblique opening that is shorter in size. As a result, the Submucosal or intramural tunnel length is shortened. For secondary VUR, there is a high rise in intravesical pressure, which overcomes the flap valve mechanism. 

Clinical Features Of Vesico Ureteric Reflux (VUR)

It is usually detected during the evaluation of associated things.

A. Detected during UTI Evaluation.

• 80% are females, average age at diagnosis- 2 to 3 years.
• VUR is usually low grade.

B.  Detected during antenatal hydronephrosis evaluation. 

• 80% are males.
• VUR is usually high grade.

C. Detected during the bladder and bowel dysfunction evaluation.

• BBD is found in about 50% of cases of VUR + UTI.

Investigations in Vesico Ureteric Reflux (VUR)

The Investigation of choice for Vesico Ureteric Reflux(VUR) is Micturating Cystourethrogram (MCU)/Voiding Cystourethrogram (VCUG). In Micturating Cystourethrogram (MCU), 

Dye is injected in the urinary bladder, known as the filling phase. 

• When micturition takes place, known as the voiding phase. 
• In the filling phase and voiding phase, multiple serial radiographs are taken.
• Micturating Cystourethrogram (MCU); -
  • Very sensitive 
  • Give better anatomical details. 
  • Grading of VUR
• VUR during the voiding phase known as high-pressure VUR, resolves with age.
• VUR during the filling phase and voiding phase known as low-pressure VUR.
  • Slight rise in the urinary bladder pressure causes reflux. 
  • Unlikely to get resolved by itself. 

Grades of Vesico Ureteric Reflux (VUR)

• Grade 1 (ureter not dilated): Reflux into the lower part of the non-dilated ureter.
• Grade 2 (ureter not dilated): Reflux into the upper part of the non-dilated ureter reaching up to the pelvis.
• Grade 3 (ureter and pelvis dilated):  Minimal or no blunting of fornices. 
• Grade 4 (ureter and pelvis dilated): Moderate to severe blunting of fornices. 
• Grade 5 (ureter is dilated, tortuous):  loss of papillary Impressions 

Management of Vesico Ureteric Reflux (VUR)

There are two kinds of VUR management. They are:

A. Nonsurgical Management: Continuous Antibiotic Prophylaxis (CAP)

B. Surgical Management

• Conventional surgery:  surgical therapy of choice. 
• Ureteric reimplantation is performed and in certain cases, combined with pyeloplasty.
• Endoscopic procedures

Frequently Asked Questions:

Q: What is the Investigation of choice in Vesico ureteric reflux?

Answer: The Investigation of choice for Vesico Ureteric Reflux(VUR) is Micturating Cystourethrogram (MCU).

Q: What changes are seen in Grade 3 of Vesico ureteric reflux?

Answer: In grade 3, the ureter and pelvis are dilated. Along with that, there is Minimal or no blunting of fornices. 

Q: What is the Length of the submucosal tunnel in neonates?

Answer: 0.5 mm.

Hope you found this blog helpful for your NEET SS Pediatrics Nephrology preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.

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