What is vesico-ureteric reflux?
Vesico-ureteric reflux (VUR) is a condition in which urine travels back up the tubes connecting the kidneys to the bladder (known as the ureters) towards the kidney. This most commonly happens while the bladder is emptying but can happen at other times. The condition can also be called vesicoureteral reflux.
VUR is usually congenital (i.e. people are born with it) and tends to improve with time. The ureter normally enters the bladder at an angle through the wall of the bladder, forming a tunnel of muscle. In VUR the ureter goes straight through the wall of the bladder, resulting in an open entrance to the tube and reflux ensues.
VUR can also occur when the pressure in the bladder gets too high, most commonly when there is a blockage. In babies this is often caused by extra flaps of tissue in the tube that carries urine out of the body (a condition known as posterior urethral valves or PUV). In adults urine outflow can be blocked due to enlargement of the prostate gland.
Vesico-ureteric reflux and kidney scarring
People who have reflux/VUR are at increased risk of getting urinary tract infections (UTIs) possibly because of incomplete emptying of the bladder. Reflux can also allow infections to get into the kidneys, causing ‘acute pyelonephritis’. Recurrent episodes of acute pyelonephritis, especially in young children (and particularly if there is a delay in treatment), can cause scarring in the kidneys. This scarring is potentially preventable.
However, before birth, VUR (especially when severe) can be associated with abnormal development of the kidney, which is called renal dysplasia. This may become more obvious as some parts of the kidney grow normally but the affected parts don’t. In these circumstances rapid treatment of urine infection in childhood may prevent scars forming, but it will not alter the original malformation.
Whether kidney scars are caused by dysplasia or by infections in infancy, they represent a form of kidney damage (often called reflux nephropathy) that can cause early onset of high blood pressure and, in some cases, progressive kidney failure. So people with scarring or reflux nephropathy should get their blood pressure measured yearly.
Reflux and reflux nephropathy also tends to run in families; babies of people with reflux have about a 20-25% chance of being born with VUR.
Vesico-ureteric reflux symptoms
VUR may be suspected if you or your child has frequent or severe UTIs.
UTI symptoms can include:
- A burning or stinging sensation when passing urine
- A sudden need to pass urine and passing urine more often
- Abdominal pain
- Foul smelling urine
In infants and young children urine infections are more difficult to diagnose as the symptoms are less specific. Babies may just have a fever, prolonged jaundice, be off their feeds or vomiting.
But sometimes reflux can be symptom free and only discovered after another family member has been diagnosed with the condition.
Sometimes VUR can be found during investigations for other issues such as kidney stones.
Vesico-ureteric reflux diagnosis
An ultrasound scan is often used to look for evidence of abnormal enlargement (dilatation) within the kidneys or ureters and to see if your or your child’s bladder is emptying fully. This can even be done when a child is still in the womb. However, other scans and tests are usually required to make a firm diagnosis of VUR:
- A bladder X-ray – also known as a micturating cysto-urethrogram (MCUG). A liquid that shows up on X-rays, called ‘contrast’ is passed into the bladder through a fine tube. Once the bladder is full, the patient is asked to pass urine in front of an X-ray machine. This test can also be used to grade VUR on a scale of one to five, where one is very mild (urine reflux does not reach your kidneys) and five the most severe (where large amounts of urine is flowing back into one or both kidneys). This is the test most commonly used to diagnose reflux in babies and young children before they are out of nappies.
- A mercapto acetyl tri-glycine reflux (MAG 3) test. A tiny amount of a radioactive substance is injected into a vein and a special camera shows the radioactivity being taken up by the kidney. Pictures are then taken as you or your child pass(es) urine. This test can only be done in children who are toilet trained.
- A dimercapto succinic acid (DMSA) scan – can sometimes be used to highlight any damage or scarring of the kidneys. This involves injecting a tiny, safe amount of a different radioactive substance into a vein and then taking pictures of your or your child’s kidneys a few hours later.
Some of these tests can be uncomfortable but babies tolerate them well and are often more upset by having to lie still whilst the X-ray is taken! Older children tend to dislike having a catheter passed into the bladder and it may be better to wait until your child is old enough to have a MAG3 test done. Speak to your kidney specialist for further advice.
Additional blood and urine tests will also be used to gauge your or your child’s kidney function and look for the presence of protein in the urine – a sign of kidney damage.
Vesico-ureteric reflux treatment
Most children with VUR, especially the lower grades, will grow out of it during childhood. Therefore management is aimed at preventing UTIs and ensuring that children can get to see their doctor/nurse quickly so that any infections can be diagnosed and treated promptly, thus avoiding kidney damage. Preventative (prophylactic) antibiotics have been shown to decrease the number of UTIs, especially in children with more severe grades of VUR.
Other ways to try to prevent UTIs include:
- drinking plenty of fluids and emptying your bladder frequently
- changing children’s nappies frequently
- wiping from front to back after going to the toilet to prevent the spread of bacteria from the gut
- emptying your bladder as soon as you feel the urge
- ‘double voiding’ – getting into the habit of going back to the toilet a few minutes later to see if there’s any more urine to pass. This allows any urine that refluxed into the ureters to drain back into the bladder so that it can be passed to the outside.
- adults should also try to empty their bladders as soon as possible after sex
If you or your child does get a UTI you may need to take antibiotics to clear it or prevent further infections. You may also need to take painkillers such as paracetamol for any discomfort – but you may be advised to avoid non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen and diclofenac which can reduce the blood supply to the kidneys.
Medications such as ACE Inhibitors and ARBs may also be prescribed to control blood pressure.
Treatments may not be required for mild kidney scarring. However, high blood pressure or proteinuria can develop during pregnancy.
Other treatments for VUR
If you or your child get frequent UTIs, despite preventative antibiotics, referral may be made to the urologists for an anti-reflux surgical procedure. There are two main forms of surgery:
- The simplest form is the injection of a material around the opening of the ureter tube into the bladder which is usually done as a day case procedure.
- The other form is a bigger procedure and involves the re-implantation of the ureter into the bladder.
Resources about vesico-ureteric reflux
If you or your child have been diagnosed with VUR and have any questions or concerns about your illness, don’t hesitate to speak to your kidney specialist or your nurse specialist at your kidney unit.
- You can also find further information, advice and helpful tips in our Just diagnosed and How can I help myself? sections.
- More information is available from the National Kidney Federation: https://www.kidney.org.uk/help-and-info/medical-information-from-the-nkf-/kidney-diseases-index/medical-info-kidney-disease-reflux-index
- More information to help the parents of children with VUR is available here: https://www.infokid.org.uk/vesicoureteral-reflux-vur-and-reflux-nephropathy
Reviewed April 2019
Need for further research
We need to understand the real relationship between urine infection and VUR and why some people do not get kidney scarring, despite having recurrent infections and VUR, while others get severe scarring with a single infection.
We also need to find effective ways to increase awareness of the need for the rapid and definitive diagnosis of UTIs out in the community. If UTIs in young children could be detected and treated very quickly (within a day or two of starting) much acquired kidney scarring could be prevented.
If you have kidney problems and are interested in research, one way in which you can help is to join our Kidney Voices for Research network. Through this network you can hear exciting updates on the latest research and share your insights into being involved in research.
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