What is posterior urethral valves?
Posterior urethral valves (PUV) is a blockage of the urethra (pee tube) that some children with male reproductive systems are born with.
Your child will need surgery to address PUV. The type of surgery that will be offered is individualized and is based on:
- how the creatinine (waste product in the blood that is normally filtered out by the kidneys) responds to bladder drainage
- how the hydronephrosis (enlargement of kidneys) or hydroureter (enlargement of ureters) looks after bladder drainage
- the size of your child
Depending on how PUV affects your child, they may need to take medications and sometimes catheters to manage PUV. They may also need additional surgeries to help with bladder and kidney function.
Managing posterior urethral valves
Surgery (initial)
Below are the types of surgeries your child may be offered to address PUV. Your child’s health-care team will determine which surgery is most appropriate for your child.
Valve ablation
A valve ablation is a procedure to physically remove the blockage from the urethra. This is done in the operating room under general anaesthesia. The surgeon will place a camera through the urethra to see the blockage and then remove the extra tissue that is causing the obstruction. A catheter will be left for drainage while the urethra heals. This catheter will be removed in the urology clinic, usually after seven to 10 days.
Valve ablation may be offered if:
- the creatinine and hydronephrosis improve with bladder drainage, and
- your child is big enough for the surgical instruments.
Usually, after valve ablation surgery, parents and caregivers are taught how to perform catheterization for their child at regular intervals during the day to check the amount of urine being stored in the bladder. Your child will have an indwelling catheter for overnight (at least 12 hours) to make sure there is no pressure on the kidneys. Children are also given bladder medications to help relax the bladder and to help the bladder empty better. Some or all of these interventions may be stopped or reduced based on how your child is doing at follow-up visits.
Urinary diversions
Vesicostomy
A vesicostomy is a surgery that involves opening the bladder to the skin to allow for continuous drainage. The bladder opening is between the belly button and penis and is covered by the diaper. This is a temporary procedure, and the vesicostomy is usually closed around the age of toilet training.
Vesicostomy may be offered if:
- the creatinine and hydronephrosis improves with bladder drainage, and
- your child is too small for the surgical instruments used for a valve ablation.
Your child will have a tube through the vesicostomy temporarily while it is healing. After that, parents and caregivers will be shown how to insert a catheter into the opening. This will need to be done one or two times a day to make sure the vesicostomy stays open. Before your child’s vesicostomy is closed, you will need to start giving your child medications to help with bladder function.
Ureterostomy
Sometimes, because the bladder was working hard to push pee out of the body through a blockage, the bladder does not work properly. Instead of being smooth and thin like a balloon, it becomes thick and irregular. When this happens, the kidneys cannot drain into the bladder easily, so the hydronephrosis, hydroureters and creatinine do not get better with bladder drainage. This is because the bladder itself is creating a second obstruction. In this case, the surgery offered will be ureterostomy. A ureterostomy is an opening of the ureter directly to the skin, close to the bladder and within the diaper area, to allow the kidney to drain. It may be on one side or both sides. This is a temporary procedure that is done to protect kidney function while the kidneys are developing.
Ureterostomy may be offered if:
- creatinine is not improving with bladder drainage, or
- the hydronephrosis and hydroureter are not improving, or they are worsening with bladder drainage.
There will be tubes in place temporarily while the ureterostomy is healing. After that, parents and caregivers will be shown how to insert a catheter into the opening. You will need to do this one or two times a day to make sure the ureterostomy stays open. Before your child’s ureterostomy is closed, you will need to start giving your child medications to help with bladder function.
Circumcision
Children with PUV are at an increased risk of urinary tract infections (UTIs). Circumcision has been shown to help decrease this risk. For this reason, you will be offered a circumcision for your child.
Medication
Antibiotic prophylaxis
Antibiotic prophylaxis is used to prevent UTIs. Children with PUV are at an increased risk of developing UTIs because of decreased bladder function, hydronephrosis/hydroureter or kidney reflux. Antibiotics may be given by mouth, or sometimes they can be given directly into the bladder through catheters.
Anticholinergics and beta 3 agonists
Oxybutynin, solifenacin, mirabegron
These medications work to relax the bladder and decrease bladder pressures. They are used when the hydronephrosis/hydroureter is not improving due to a thick bladder in order to prepare for closing a vesicostomy or ureterostomy, or if there is urinary incontinence (if your child cannot control when they pee). If your child has difficulty with bladder emptying, this medication may make that problem worse.
Alpha blockers
Tamsulosin, silodosin
These medications help the bladder empty more effectively by relaxing the muscles around the bladder neck. They may also help decrease hydronephrosis and hydroureter by relaxing the entrance of the ureters into the bladder.
Additional surgeries
Redo-ablation
Sometimes, children will need a second valve ablation surgery. If a repeat voiding cystourethrogram (VCUG) shows persistent blockage in the urethra, your child will need another valve ablation to remove it. The recovery is very similar to the initial valve ablation.
Secondary diversions
Vesicostomy or ureterostomy as described above may be offered after a valve ablation if your child has worsening hydronephrosis, develops UTIs or has rising creatinine. This happens because of impaired bladder function despite no physical obstruction in the urethra.
Continent catheterizable channel
Continent catheterizable channel (Mitrofanoff/Monti) is done for children who require intermittent catheterization but do not tolerate them through the penis. The appendix (or a piece of the bowel) is used to make a channel from the bladder to the bellybutton. This channel is used for catheterization intermittently throughout the day and night. This allows your child to effectively empty the bladder without pain, and it helps with independence and continence.
Botulinum toxin type A
Botulinum toxin type A, or Botox®, is used as a replacement for anticholinergic medications. It is injected directly into the bladder wall. This is done in the operating room and requires general anaesthesia.
Botox® helps to relax the bladder, decrease pee accidents and lower bladder pressures. Because Botox® injections can make it harder for the bladder to empty on its own, most children who have this are already doing intermittent catheters. The benefit of Botox® is that it replaces the need for daily oral medication, but the effect only lasts four to six months, and each time it is re-done, it requires anaesthesia and a trip to the operating room. In rarer cases, Botox® may be injected into the bladder neck to help relax the exit of the bladder, which makes peeing easier and helps drain the kidneys. However. this may sometimes also cause continuous leaking of pee.
Suprapubic tube (SPT)
A suprapubic tube (SPT) is a type of catheter that is inserted through the abdominal wall, directly into the bladder. This is done under anaesthesia or sedation. SPTs may be offered for children who need to start catheterizing but are not ready to do it through the penis or to have a catheterizable channel. They are used for overnight drainage and to check for poor emptying during the day. SPTs need to be changed every four to six weeks. They are a temporary solution to needing to catheterize. SPTs not a good long-term option because they put children at an increased risk of UTIs.