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Posterior urethral valves: OverviewPPosterior urethral valves: OverviewPosterior urethral valves: OverviewEnglishUrologyChild (0-12 years)Kidneys;Bladder;UrethraRenal system/Urinary systemConditions and diseasesCaregivers Adult (19+)NA2023-07-18T04:00:00Z10.100000000000053.40000000000002344.00000000000Health (A-Z) - ConditionsHealth A-Z<p>Find out what to expect if you have a child with posterior urethral valves (PUV). This document reviews the condition and how it is managed with medications, tests, interventions and surgeries.</p><h2>What is posterior urethral valves (PUV)?</h2><p>Posterior urethral valves (PUV) is a blockage of the urethra (pee tube) that some children with male reproductive systems are born with. This blockage happens early on in pregnancy while the urethra is forming. This blockage makes it difficult for babies to pee. PUV is found in one to two in 10,000 pregnancies. </p><p>Babies suspected to have PUV should be born at a high-risk fetal centre and should be seen by paediatric specialists shortly after birth. PUV impacts the bladder, the kidneys and ureters and requires surgery once the baby is born. Babies with PUV may also have breathing problems because PUV can impact amniotic fluid volume, and fluid is important for lung development.</p><p>Even once the blockage is removed, many children with PUV will have long-term effects on their kidney and bladder function. These children will need to be followed closely by urology and nephrology teams. </p><h2>Key points</h2><ul><li>Some children with male reproductive systems are born with a blockage of the urethra. This is called posterior urethral valves (PUV).</li><li>PUV is a life-long chronic condition that requires regular follow-up with your child’s health-care team.</li><li>The condition occurs on a spectrum, meaning that it may affect each child differently.</li><li>Most children with PUV will have issues with bladder function.</li><li>Children with PUV are at increased risk of chronic kidney disease. Some children will need a kidney transplant.</li></ul><h2>Signs and symptoms of PUV</h2><p>The signs and symptoms of PUV in infants and older children include:</p><ul><li><a href="/article?contentid=935&language=english">urinary tract infections (UTIs)</a></li><li>poor feeding</li><li>a weak pee stream </li><li>pushing hard to pee </li><li>abnormal blood work (electrolytes and creatinine)</li><li>abnormal ultrasound findings</li><li>abdominal distension (swelling)</li></ul><h2>How is PUV diagnosed?</h2><h3>Prenatal diagnosis</h3><p>Sometimes, PUV is detected during pregnancy by abnormalities on prenatal ultrasounds, usually during the second trimester. These abnormalities may include:</p><ul><li>dilatation (enlargement/swelling) of the kidneys (hydronephrosis) </li><li>dilation of the ureters (hydroureter)</li><li>a very full bladder</li><li>thickening of the bladder wall </li><li>low, or no, fluid around the baby </li></ul><p>If all or some of these findings are detected, you will be referred to a paediatric urology and nephrology team for detailed prenatal counselling. The team(s) will discuss possible causes of the ultrasound findings and prepare you for what to expect when your baby is born. </p><h3>Postnatal diagnosis</h3><p>Sometimes, PUV is not detected during pregnancy, but instead after babies are born. It is rarely diagnosed in older children. Usually, when PUV is diagnosed after birth, it is because children develop symptoms such as UTIs, poor feeding, failure to thrive, a weak pee stream or they are pushing hard to pee. </p><h4>Postnatal diagnostic tests and procedures</h4><p>Most babies with PUV will have to be admitted to the hospital for monitoring, to have the tests required to diagnose PUV and to have surgery to remove or bypass the blockage. </p><h5>Ultrasound</h5><p>Your child will have ultrasounds to look at the degree of hydronephrosis and hydroureter and see how the bladder looks. The health-care team will perform ultrasounds frequently to look for changes. </p><h5>Bladder decompression</h5><p>Babies and some older children will need to have a catheter or a stent placed through the penis and into the bladder. This will bypass the blockage and allow the bladder and kidneys to drain. The tube usually stays in place for several days to gather information about how the kidneys and bladder look with drainage. This information helps the health-care team decide which PUV surgery is best for your child. </p><h5>Voiding cystourethrogram (VCUG)</h5><p>A <a href="/article?contentid=1294&language=english">voiding cystourethrogram (VCUG)</a> is the test that is used to diagnose PUV. This test requires a small catheter to be placed through the penis, into the bladder. A contrast material (dye) is then put into the bladder through the catheter, and pictures are taken with an X-ray. The pictures show the pee passing through the urethra and allow the health-care team to see if there is a blockage and where the blockage is. The VCUG also tells the team if there is kidney reflux (backwards flow of pee from the bladder to the kidneys), which sometimes happens with PUV.</p><h5>Blood work</h5><p>Your child will have frequent blood work to check on kidney function (by checking levels of creatinine, a waste product that is usually filtered out of the blood by the kidneys) and electrolytes to make sure that the bladder drainage is working. When the bladder is emptied with a tube after a blockage, a lot of pee will be drained. This creates a risk of dehydration and unbalanced electrolytes, which can be dangerous. Frequent blood work and assessment by the nephrology team will help to avoid this. </p><h2>How is PUV treated?</h2><h3>Surgery</h3><p>Your child will need surgery to resolve the blockage. The type of surgery that is offered will be based on:</p><ul><li>how the creatinine responds to bladder drainage</li><li>how the hydronephrosis/hydroureter looks after bladder drainage</li><li>the size of your child</li></ul><p>Sometimes, children will need additional surgeries if they have persistent blockage in the urethra or have impaired bladder function and cannot catheterize through the penis.</p><h3>Medication</h3><p>PUV is also managed with medications. Your child may need medication to:</p><ul><li>prevent UTIs</li><li>relax the bladder and decrease bladder pressure</li><li>help the bladder empty more effectively</li></ul><p>For more information about treatment for PUV, including the types of surgeries and medications your child may have, please see <a href="/article?contentid=4163&language=english">Posterior urethral valves: Treatment with medication and surgery</a>.</p><h2>Complications of PUV</h2><h3>Bladder dysfunction</h3><p>Because the blockage in the urethra has been there since before birth, the bladder had to work hard to push pee through the blockage for the duration of pregnancy, which may cause irreversible damage to the bladder. The bladder is a smooth muscle and normally squeezes pee out with no resistance, but in PUV there is a lot of resistance because of the blockage. As a result, babies with PUV have very small, thick, high-pressure bladders. This causes the urine to accumulate in the kidneys, which negatively impacts kidney function. Over time, the bladder damage and having to squeeze harder than normal to empty eventually cause the muscle to not be able to squeeze effectively. The extent of this damage is different for every child. Most children with PUV will have some degree of bladder dysfunction that may range from problems with their bladder emptying (high volumes of pee left over after urinating) and pee accidents (because of small bladder size or leftover pee leaking) all the way to bladder failure. Children with PUV may need medicines to help with bladder storage or emptying, and some will need to use catheters to empty the bladder. </p><h4>How catheters can help with bladder dysfunction</h4><p>Caregivers and children are taught how to use catheters in the urology clinic. Sometimes, catheters are used for overnight drainage, usually for 10–12 hours. This is because children with PUV make a lot of pee overnight, and when it is stored in the bladder, it puts pressure on the kidneys. Having a catheter for this time takes that pressure off the kidneys and helps to preserve kidney function. Some children must use catheters during the day too. This is called <a href="/article?contentid=978&language=english">clean intermittent catheterization</a> and means that every few hours during the day, a catheter is used to empty the bladder, and then the catheter is removed. High bladder volumes increase the risk of infection, so using catheters also helps to prevent infections. Finally, children with PUV sometimes have problems with pee accidents that do not respond to medications. Catheters are used to help these children achieve social continence (to control when they empty pee from their bladder). In children who do not tolerate inserting catheters into the penis due to difficulty or discomfort, a Mitrofanoff channel can be created to make it easier. For more information about this, please see <a href="/article?contentid=4163&language=english">Posterior urethral valves: Treatment with medication and surgery</a>.</p><p>If a child with PUV has worsening hydronephrosis/hydroureter on ultrasound, or their kidney function is worsening, a catheter may be inserted into their bladder for seven to 14 days. Then, the tests (ultrasound and blood work) will be repeated to see if having the bladder empty makes things look better. This will tell the team if catheters would benefit your child.</p><h3>Chronic kidney disease (CKD) risk</h3><p>Up to 25% of children with PUV will develop chronic kidney disease (CKD) at some point in childhood. In Ontario, 30% of adults with PUV have CKD, compared to 0.5% of people without PUV. There are several potential causes of CKD in children with PUV, such as kidney problems that happened before the baby was born (e.g., cysts, dysplasia). However, many of the kidney issues that children with PUV experience are because of poor bladder function that has negatively impacted kidney function over time. CKD is managed in partnership with the paediatric nephrology team who will suggest medications and dietary changes to stop or slow down progression. </p><h3>End-stage renal disease (ESRD)</h3><p>End-stage renal disease (ESRD) means that the kidneys can no longer handle the demands of the body. At this point, a child needs either dialysis or a kidney transplant. About 10% of children with PUV at SickKids need <a href="/article?contentid=44&language=english">dialysis</a> or a <a href="https://www.aboutkidshealth.ca/transplant">kidney transplant</a>. About 8% of adults with PUV require dialysis or kidney transplant compared to less than 1% of the general population.</p><h2>Resources</h2><p>Rickard, M., Lorenzo, A.J., Richter, J. et al. (2023, May 9). Implementation of a standardized clinical pathway in a dedicated posterior urethral valves clinic: short-term outcomes. <em>Pediatric Nephrology.</em> Retrieved from: <a href="https://doi.org/10.1007/s00467-023-06040-7">https://doi.org/10.1007/s00467-023-06040-7</a></p><p> <a href="https://youtu.be/kkpuunOMq7M">SickKids YouTube PUV clinic video</a></p>

 

 

 

 

Posterior urethral valves: Overview4162.00000000000Posterior urethral valves: OverviewPosterior urethral valves: OverviewPEnglishUrologyChild (0-12 years)Kidneys;Bladder;UrethraRenal system/Urinary systemConditions and diseasesCaregivers Adult (19+)NA2023-07-18T04:00:00Z10.100000000000053.40000000000002344.00000000000Health (A-Z) - ConditionsHealth A-Z<p>Find out what to expect if you have a child with posterior urethral valves (PUV). This document reviews the condition and how it is managed with medications, tests, interventions and surgeries.</p><h2>What is posterior urethral valves (PUV)?</h2><p>Posterior urethral valves (PUV) is a blockage of the urethra (pee tube) that some children with male reproductive systems are born with. This blockage happens early on in pregnancy while the urethra is forming. This blockage makes it difficult for babies to pee. PUV is found in one to two in 10,000 pregnancies. </p><p>Babies suspected to have PUV should be born at a high-risk fetal centre and should be seen by paediatric specialists shortly after birth. PUV impacts the bladder, the kidneys and ureters and requires surgery once the baby is born. Babies with PUV may also have breathing problems because PUV can impact amniotic fluid volume, and fluid is important for lung development.</p><p>Even once the blockage is removed, many children with PUV will have long-term effects on their kidney and bladder function. These children will need to be followed closely by urology and nephrology teams. </p><h2>Key points</h2><ul><li>Some children with male reproductive systems are born with a blockage of the urethra. This is called posterior urethral valves (PUV).</li><li>PUV is a life-long chronic condition that requires regular follow-up with your child’s health-care team.</li><li>The condition occurs on a spectrum, meaning that it may affect each child differently.</li><li>Most children with PUV will have issues with bladder function.</li><li>Children with PUV are at increased risk of chronic kidney disease. Some children will need a kidney transplant.</li></ul><h2>Signs and symptoms of PUV</h2><p>The signs and symptoms of PUV in infants and older children include:</p><ul><li><a href="/article?contentid=935&language=english">urinary tract infections (UTIs)</a></li><li>poor feeding</li><li>a weak pee stream </li><li>pushing hard to pee </li><li>abnormal blood work (electrolytes and creatinine)</li><li>abnormal ultrasound findings</li><li>abdominal distension (swelling)</li></ul><h2>How is PUV diagnosed?</h2><h3>Prenatal diagnosis</h3><p>Sometimes, PUV is detected during pregnancy by abnormalities on prenatal ultrasounds, usually during the second trimester. These abnormalities may include:</p><ul><li>dilatation (enlargement/swelling) of the kidneys (hydronephrosis) </li><li>dilation of the ureters (hydroureter)</li><li>a very full bladder</li><li>thickening of the bladder wall </li><li>low, or no, fluid around the baby </li></ul><p>If all or some of these findings are detected, you will be referred to a paediatric urology and nephrology team for detailed prenatal counselling. The team(s) will discuss possible causes of the ultrasound findings and prepare you for what to expect when your baby is born. </p><h3>Postnatal diagnosis</h3><p>Sometimes, PUV is not detected during pregnancy, but instead after babies are born. It is rarely diagnosed in older children. Usually, when PUV is diagnosed after birth, it is because children develop symptoms such as UTIs, poor feeding, failure to thrive, a weak pee stream or they are pushing hard to pee. </p><h4>Postnatal diagnostic tests and procedures</h4><p>Most babies with PUV will have to be admitted to the hospital for monitoring, to have the tests required to diagnose PUV and to have surgery to remove or bypass the blockage. </p><h5>Ultrasound</h5><p>Your child will have ultrasounds to look at the degree of hydronephrosis and hydroureter and see how the bladder looks. The health-care team will perform ultrasounds frequently to look for changes. </p><h5>Bladder decompression</h5><p>Babies and some older children will need to have a catheter or a stent placed through the penis and into the bladder. This will bypass the blockage and allow the bladder and kidneys to drain. The tube usually stays in place for several days to gather information about how the kidneys and bladder look with drainage. This information helps the health-care team decide which PUV surgery is best for your child. </p><h5>Voiding cystourethrogram (VCUG)</h5><p>A <a href="/article?contentid=1294&language=english">voiding cystourethrogram (VCUG)</a> is the test that is used to diagnose PUV. This test requires a small catheter to be placed through the penis, into the bladder. A contrast material (dye) is then put into the bladder through the catheter, and pictures are taken with an X-ray. The pictures show the pee passing through the urethra and allow the health-care team to see if there is a blockage and where the blockage is. The VCUG also tells the team if there is kidney reflux (backwards flow of pee from the bladder to the kidneys), which sometimes happens with PUV.</p><h5>Blood work</h5><p>Your child will have frequent blood work to check on kidney function (by checking levels of creatinine, a waste product that is usually filtered out of the blood by the kidneys) and electrolytes to make sure that the bladder drainage is working. When the bladder is emptied with a tube after a blockage, a lot of pee will be drained. This creates a risk of dehydration and unbalanced electrolytes, which can be dangerous. Frequent blood work and assessment by the nephrology team will help to avoid this. </p><h2>How is PUV treated?</h2><h3>Surgery</h3><p>Your child will need surgery to resolve the blockage. The type of surgery that is offered will be based on:</p><ul><li>how the creatinine responds to bladder drainage</li><li>how the hydronephrosis/hydroureter looks after bladder drainage</li><li>the size of your child</li></ul><p>Sometimes, children will need additional surgeries if they have persistent blockage in the urethra or have impaired bladder function and cannot catheterize through the penis.</p><h3>Medication</h3><p>PUV is also managed with medications. Your child may need medication to:</p><ul><li>prevent UTIs</li><li>relax the bladder and decrease bladder pressure</li><li>help the bladder empty more effectively</li></ul><p>For more information about treatment for PUV, including the types of surgeries and medications your child may have, please see <a href="/article?contentid=4163&language=english">Posterior urethral valves: Treatment with medication and surgery</a>.</p><h2>Complications of PUV</h2><h3>Bladder dysfunction</h3><p>Because the blockage in the urethra has been there since before birth, the bladder had to work hard to push pee through the blockage for the duration of pregnancy, which may cause irreversible damage to the bladder. The bladder is a smooth muscle and normally squeezes pee out with no resistance, but in PUV there is a lot of resistance because of the blockage. As a result, babies with PUV have very small, thick, high-pressure bladders. This causes the urine to accumulate in the kidneys, which negatively impacts kidney function. Over time, the bladder damage and having to squeeze harder than normal to empty eventually cause the muscle to not be able to squeeze effectively. The extent of this damage is different for every child. Most children with PUV will have some degree of bladder dysfunction that may range from problems with their bladder emptying (high volumes of pee left over after urinating) and pee accidents (because of small bladder size or leftover pee leaking) all the way to bladder failure. Children with PUV may need medicines to help with bladder storage or emptying, and some will need to use catheters to empty the bladder. </p><h4>How catheters can help with bladder dysfunction</h4><p>Caregivers and children are taught how to use catheters in the urology clinic. Sometimes, catheters are used for overnight drainage, usually for 10–12 hours. This is because children with PUV make a lot of pee overnight, and when it is stored in the bladder, it puts pressure on the kidneys. Having a catheter for this time takes that pressure off the kidneys and helps to preserve kidney function. Some children must use catheters during the day too. This is called <a href="/article?contentid=978&language=english">clean intermittent catheterization</a> and means that every few hours during the day, a catheter is used to empty the bladder, and then the catheter is removed. High bladder volumes increase the risk of infection, so using catheters also helps to prevent infections. Finally, children with PUV sometimes have problems with pee accidents that do not respond to medications. Catheters are used to help these children achieve social continence (to control when they empty pee from their bladder). In children who do not tolerate inserting catheters into the penis due to difficulty or discomfort, a Mitrofanoff channel can be created to make it easier. For more information about this, please see <a href="/article?contentid=4163&language=english">Posterior urethral valves: Treatment with medication and surgery</a>.</p><p>If a child with PUV has worsening hydronephrosis/hydroureter on ultrasound, or their kidney function is worsening, a catheter may be inserted into their bladder for seven to 14 days. Then, the tests (ultrasound and blood work) will be repeated to see if having the bladder empty makes things look better. This will tell the team if catheters would benefit your child.</p><h3>Chronic kidney disease (CKD) risk</h3><p>Up to 25% of children with PUV will develop chronic kidney disease (CKD) at some point in childhood. In Ontario, 30% of adults with PUV have CKD, compared to 0.5% of people without PUV. There are several potential causes of CKD in children with PUV, such as kidney problems that happened before the baby was born (e.g., cysts, dysplasia). However, many of the kidney issues that children with PUV experience are because of poor bladder function that has negatively impacted kidney function over time. CKD is managed in partnership with the paediatric nephrology team who will suggest medications and dietary changes to stop or slow down progression. </p><h3>End-stage renal disease (ESRD)</h3><p>End-stage renal disease (ESRD) means that the kidneys can no longer handle the demands of the body. At this point, a child needs either dialysis or a kidney transplant. About 10% of children with PUV at SickKids need <a href="/article?contentid=44&language=english">dialysis</a> or a <a href="https://www.aboutkidshealth.ca/transplant">kidney transplant</a>. About 8% of adults with PUV require dialysis or kidney transplant compared to less than 1% of the general population.</p><h2>Can PUV be prevented?</h2><p>PUV is a condition that develops before a child is born. There is no way to prevent it.</p><h2>Tests to monitor and manage PUV</h2><h3>Ultrasound</h3><p>Ultrasound is used for regular monitoring because it is non-invasive, does not expose your child to radiation and provides good information about how the kidneys and bladder look. The health-care team will use ultrasound to:</p><ul><li>watch for changes in hydronephrosis and hydroureter</li><li>look at the structure of the bladder </li><li>measure how much pee the bladder is holding and how much is left over after your child pees</li></ul><h3>Voiding cystourethrogram (VCUG)</h3><p>Your child may need to have another <a href="/article?contentid=1294&language=english">voiding cystourethrogram (VCUG)</a> after they have been diagnosed with PUV if, during follow-up, hydronephrosis/hydroureter does not improve or gets worse. The VCUG is done to check for residual valve tissue and to monitor kidney reflux. </p><h3>Video urodynamics (VUDS)</h3><p> <a href="/article?contentid=1291&langugage=english">Video urodynamics (VUDS)</a> is a test that is done to check for bladder function. It measures bladder pressure, capacity (how much pee the bladder can store), if there is pee left behind after peeing (post-void residual) and how effectively the bladder can squeeze. A small catheter will be inserted through the penis into the bladder, and another will go into the rectum. A technologist will take X-ray images during the test. Your child will need a bowel cleanout beforehand to ensure there is no constipation because constipation interferes with test accuracy. </p><h3>Nuclear medicine tests</h3><p>These tests may be suggested to:</p><ul><li>check how much each kidney contributes to overall kidney function </li><li>check for scarring on the kidney (<a href="/article?contentid=1299&language=english">DMSA scan</a>), which may happen after infection</li><li>measure drainage time of the kidneys (<a href="/article?contentid=1300&language=english">Lasix renal scan</a>)</li></ul><p>Your child may be given a radioisotope through an IV (intravenous line) to give a clear picture of the kidneys. Your child may also have a catheter inserted and be given a diuretic medication. </p><h3>Flow study</h3><p>This test is done at each clinic visit once your child is toilet trained. It is done in a urology clinic and includes an ultrasound scan of the bladder to check the volume. Your child will then pee into a special toilet that can measure the force of the pee stream, and the bladder is scanned afterwards to see if the bladder is empty. This test gives the team useful information about how the bladder is working. </p><h3>Blood work</h3><p>Your child will require regular blood work to monitor kidney function by measuring creatinine, electrolytes and other markers, particularly if your child has developed chronic kidney disease (CKD). </p><h2>Follow-up schedule</h2><p>The timing and frequency of follow-up is individualized and based on how your child is doing. On average, for the first year, children are seen more often, usually every three months. After that, visits are usually every six months and then once per year when they reach school age as long as they are doing well. Children may have to be seen more frequently during “milestone” periods.</p><h3>PUV milestone</h3><h4>Prenatal detection</h4><p>This time is important because if there are ultrasound features detected that could suggest a PUV diagnosis, families can receive counseling by urology and nephrology teams to prepare for what to expect once the baby is born.</p><h4>Time of presentation</h4><p>This is the time of confirming the diagnosis and addressing the blockage. Your child may be sick and need treatment in addition to having the blockage removed. This time may be stressful for parents/caregivers and the child.</p><h4>Toilet training age</h4><p>Because all children with PUV will experience some degree of bladder dysfunction (problems with peeing), toilet training age may be when the condition first becomes apparent. Your child may have difficulty toilet training, get infections, have pee accidents and develop constipation at this time. Constipation also impacts bladder function.</p><h4>School age</h4><p>School age may be another time that bladder dysfunction becomes evident. This is when children gain more independence at school and may not be as compliant with going to the bathroom, which may mean that they hold for longer periods of time. Holding for too long may cause infections, worsen hydronephrosis and eventually raise creatinine.</p><h4>Teenage years</h4><p>The final paediatric milestone is during the teenage years. At this stage, adolescents have even more independence and may have further issues with sticking to care suggestions, such as regular peeing, double peeing, managing catheters or taking medications. This is also the time that your teen's health-care team will start to prepare them to <a href="/article?contentid=3924&language=english">transition to adult care</a>.</p><h2>Resources</h2><p>Rickard, M., Lorenzo, A.J., Richter, J. et al. (2023, May 9). Implementation of a standardized clinical pathway in a dedicated posterior urethral valves clinic: short-term outcomes. <em>Pediatric Nephrology.</em> Retrieved from: <a href="https://doi.org/10.1007/s00467-023-06040-7">https://doi.org/10.1007/s00467-023-06040-7</a></p><p> <a href="https://youtu.be/kkpuunOMq7M">SickKids YouTube PUV clinic video</a></p>Posterior urethral valves: OverviewFalse

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