Neurogenic Bladder Background Information
What is neurogenic bladder?
Neurogenic bladder is a condition in which nerve damage causes the bladder to lose its normal function. There are two categories of neurogenic bladder. The first is a large volume sleepy (a.k.a., flaccid) bladder that does not empty well. The second, and more common, is a very small, tight bladder that is spastic, which leads to high pressures within the bladder. Both patterns can lead to incontinence (urinary leakage), urinary tract infections and kidney damage. The high pressures caused by a spastic bladder carry a higher risk of kidney damage. The function of the urinary sphincter can also be affected. The sphincter is the valve that helps us hold our urine and not leak. The sphincter can be weak, leading to urinary leakage or it can be spastic and unable to relax.
What causes neurogenic bladder?
Anything that damages the nerves to the bladder can lead to neurogenic bladder. This includes spinal cord injury from trauma or birth defects of the spinal cord such as spina bifida. There are many neurologic diseases that can lead to neurogenic bladder including multiple sclerosis, transverse myelitis, cerebral palsy, diabetes, peripheral neuropathy, head injury, vertebral disk herniation, and stroke.
Do I need to see a urologist if I have neurogenic bladder?
It depends. Most people with neurogenic bladder can be managed very well by their primary care provider. This is especially true for people with neurogenic bladder caused by neurologic diseases like dementia, stroke, diabetes, Parkinson’s disease or multiple sclerosis. These, and most other neurologic diseases, are unlikely to result in kidney damage from the neurogenic bladder so it is a lower risk situation. People with low-risk neurogenic bladder usually just need medicines to help with frequent urination or urinary leakage; they usually don’t need catheters and if they are doing well, they don’t need their neurogenic bladder checked up on regularly. In contrast, people with neurogenic bladder due to spinal cord injury, spina bifida or cerebral palsy should probably see a urologist. These people are at higher risk for urinary tract infections and kidney damage if the bladder is not managed properly. A urologist can do testing to assess the degree of risk to the kidneys from the neurogenic bladder and a urologist has access to some treatments that a primary provider does not, like botulinum toxin or surgeries.
How is neurogenic bladder diagnosed?
A thorough conversation between the patient and doctor, as well as a careful physical exam can reveal much about the cause of urinary symptoms. However, additional testing is often required. One of the most helpful tests in the evaluation of neurogenic bladder is called a urodynamic test. Urodynamic testing is also called a cystometrogram (CMG). In this test, catheter (a.k.a., tube) about the size of a piece of spaghetti is passed into the bladder and another catheter is placed into the rectum. Both of these catheters have pressure monitors in them. The bladder is filled and several measures of the bladder and sphincter function are done. These measures can include the cause of incontinence, the volume of fluid that the bladder can hold, and the pressures in the bladder while filling and while emptying. This test allows the urologist to tailor treatments to each person, depending upon factors like the cause of incontinence and the size and pressure of the bladder. It also identifies people with dangerous pressures within their bladder that might lead to kidney damage.
What are the goals of treatment for neurogenic bladder?
The goals for the treatment of neurogenic bladder are to eliminate bothersome leakage and create a low-pressure reservoir that will preserve kidney function. In many cases this involves conservative management with medical therapy or the use of botulinum toxin, but in other cases surgery may be indicated.
What are some of the treatments for neurogenic bladder?
The mainstay of treatment for neurogenic bladder is to use catheters (a.k.a., tubes) about the thickness of a pencil to help empty the bladder. In the minority of people who have a flaccid/sleepy bladder, catheters may be the only treatment needed. However, the majority of people with neurogenic bladder have a spastic bladder; in these cases, we need to calm down the bladder spasms with medicines or surgery and then use catheters to help empty the bladder. If we don’t calm down the spastic bladder then the high pressures can cause urinary leakage, infections and kidney damage.
When and why are catheters used in neurogenic bladder?
Catheters help empty the bladder when the bladder cannot empty on its own. A catheter can also help with leakage by keeping the bladder empty. One way to do this is with an indwelling catheter; this means a catheter that stays in all the time and gets changed for a new one typically every month. Indwelling catheters can cause more infections than intermittent catheterization (described below) and have the disadvantage of having a bag that you have to carry everywhere; but indwelling catheters can work really well for some people, especially if they don’t have the dexterity to do intermittent catheterization.
Intermittent catheterization is a mainstay of treatment. Because people with neurogenic bladder frequently have difficulty emptying their bladder, many require a catheter to do so. Intermittent catheterization specifically means inserting a catheter each time one needs to empty and then removing it after. It makes perfect sense that someone who has a paralyzed or weak bladder would need help emptying their bladder. It is not so obvious why someone with a spastic bladder and urinary incontinence would need to catheterize to empty. In spastic bladder, we aim to reduce the number and intensity of bladder spasms and incontinence episodes using medicines or surgery (see below). With mild cases of neurogenic bladder, we can sometimes achieve a good balance between quieting down the unwanted bladder spasms while not weakening the normal contractions of the bladder that we rely on to urinate. These people can then urinate normally and not require intermittent catheterization. But, in cases of more severe neurogenic bladder, such as often occurs with spinal cord injury or spina bifida, when we calm down the unwanted bladder spasms we find that the neurogenic bladder often does not have any underlying normal contractions. In a sense, our goal with the severe spastic neurogenic bladder is to use medicines or surgery to convert it to something closer to a sleep/flaccid bladder. Although these treatments help with the leakage symptoms they can make it more difficult to empty. Therefore, these treatments are often combined with catheterization, allowing people to be dry and to empty on a more convenient schedule. The advantages of intermittent (a.k.a. “in and out”) catheterization over wearing a catheter 24 hours a day (a.k.a. indwelling catheter or Foley catheter) are several. First, intermittent catheterization allows a person to not have to wear a catheter attached to a bag all the time. Second, bladder infection risk is lower with intermittent catheterization. Third, intermittent catheterization puts the bladder through its normal cycle of filling and emptying which promotes bladder health, whereas wearing a catheter all the time causes the bladder to shrivel up from disuse over time. Finally, bladder cancer, bladder stones and scar tissue of the urethra or tearing of the urethra are all consequences of wearing a catheter all the time. Intermittent catheterization is done by the person with neurogenic bladder or their caregiver. It is not a sterile process; research has shown that using a “clean” intermittent catheterization (which is quicker and easier) is just as good as a sterile intermittent catheterization when it comes to minimizing the risk of bladder infections. Some people use a new catheter each time whereas others wash the catheters and re-use them for a week or more; again, research has shown no difference in infection rates. Catheters are covered by insurance.
What is a suprapubic catheter or suprapubic tube?
Most people with an indwelling catheter have one that goes through their urethra, which is the pee hole that comes out the penis or vagina. This is sometimes called a Foley, which refers to any catheter that has a balloon on the inside end of it to help hold it in the bladder and not fall out. The other type of indwelling catheter is a suprapubic catheter. This is also typically a Foley catheter, but it is inserted through a small puncture hole on the lower abdomen, about an inch above the top of the pubic hairline using a 15-minute surgery. Just like a urethral indwelling catheter, the suprapubic catheter needs to be changed monthly; and, just like the urethral catheter, this catheter change just takes a few minutes and can be done by a nurse or caregiver.
How do medicines help with managing bladder pressures and leakage?
Often the first line therapy for people that have urgency of urination, urinary frequency and leakage from neurogenic bladder is anti-cholinergic medicines; second line medicines are beta-3-agonists. These medicines act to relax the bladder and decrease leakage and urgency of urination from bladder spasms or overactivity. Anti-cholinergic medicines are notorious for causing side effects and often people need to change from one medicine to another to find one that is tolerated well. Beta-3-agonists can be added to anti-cholinergic medicines to achieve a better combined effect, or may be used instead of anti-cholinergics when those don’t work or cause bad side effects. Treatment with anti-cholinergic medicines may be all that is required for people that do not have severely contracted bladders with high pressures in the bladder. As described above, some people with a mild case of neurogenic bladder might be able to urinate normally after treatment with anti-cholinergics, whereas people with more severe neurogenic bladder might have to use anti-cholinergics in conjunction with catheters to empty the bladder.
Botulinum toxin injection (Botox) is for bladder spasms that do not improve with medications
Botulinum toxin is a drug that is used to paralyze the bladder muscle. The medicine is injected into the muscle of the bladder using a scope in the clinic or the operating room. Just like anti-cholinergic or beta-3-agonist medicines, botulinum toxin can decrease the amount of leakage from bladder spasms and decrease dangerous pressures in the bladder; but botulinum toxin is stronger than the medicines and often works when the medicines have stopped working. Unfortunately, the medicine only lasts between 6-9 months and then must be reinjected. The bladder muscle can become completely paralyzed and unable to empty on its own. In people with mild neurogenic bladder, we can give a low dose of botulinum toxin to control the spasms and the person can urinate normally. In more severe cases, we will use a higher dose and the goal is to paralyze the bladder and then empty using intermittent catheterization. Botulinum toxin can also be used to treat people with overactive sphincters and is injected at the level of the sphincter to relieve the blockage to normal urination.
Bladder augmentation is surgery to enlarge the bladder and block spasms
When the above treatments fail or when the bladder is severely contracted and has pressures that may lead to kidney failure, surgery to expand the bladder volume and decrease the pressures is often the best method of treatment. This surgery is known as bladder augmentation. In this surgery, a patch of bowel is brought down to the bladder and used to dramatically increase the volume of the bladder. This eliminates problems with bladder spasms and urinary incontinence and creates a large capacity low-pressure reservoir for urine. Think of it like a large dome added to a building where the bladder is the building. The bladder capacity after augmentation is usually about 500 ml, or 16 ounces. People need to perform intermittent catheterization to drain the bladder after augmentation.
A Mitrofanoff or Monti catheterizable channel is for intermittent catheterization through an opening in the belly button
Most people who do intermittent catheterization do so through their natural urethra. But, some people who need to be on intermittent catheterization are unable to pass a catheter through their urethra. The most common reason people have difficulty accessing the urethra is because they use a wheelchair for mobility and find it difficult to access their urethra in their wheelchair. This problem is more common in women, but even many men can have trouble accessing their urethra in their chair due to problems with hand coordination after spinal cord injury. Other reasons people have trouble with urethral catheterization include scarring in the urethra or pain. In these situations, a small caliber tube of intestine can be created for catheterization that comes out to the belly button (a.k.a., umbilicus) or somewhere else on the lower abdomen. This tube is called a Monti tube or a Mitrofanoff tube, depending on which type of bowel we use to make it. This is like a new urethra and like the urethra it has a valve where it enters the bladder. When successful, it should not leak urine and the valve can only be opened by passing a catheter through the tube into the bladder. Often, this tube is created at the time of bladder augmentation but some people do get a Mitrofanoff/Monti without an augment. The surgery to create a Mitrofanoff/Monti takes about 2-4 hours without an augment, or 3-5 hours with an augment; it is done through a lower abdominal incision and you typically stay in the hospital for 3-7 days after surgery. The opening on the abdominal wall is pink like the inside of your mouth and is about the size of a pencil eraser. It is often concealed in the belly button. People catheterize this small stoma to drain the bladder 4-6 times per day.
What’s the difference between a Mitrofanoff and a suprapubic catheter?
It can be easy to confuse a Mitrofanoff with a suprapubic catheter (a.k.a., suprapubic tube) so let’s explain the difference. A Mitrofanoff is an opening in the belly button or abdominal wall made out of intestine. This intestinal tube then connects to the bladder where it has valve so that it won’t leak urine out the belly button. Urine only empties out when you pass a catheter through the Mitrofanoff, opening that valve. A suprapubic tube does not involve any intestine. It is just a catheter that goes through the skin on the lower abdomen just above the pubic hair and directly into the bladder. Making a Mitrofanoff is a 2-4 hour surgery that involves opening the belly and you stay in the hospital for a few days. A suprapubic catheter is inserted with a 15-minute surgery using just a puncture wound and you go home the same day. A suprapubic tube is different from a Mitrofanoff in that you need to wear the suprapubic tube all day (i.e., it is an indwelling catheter), whereas the Mitrofanoff involves intermittent catheterization. If you were to try intermittent catheterization through a suprapubic hole then the hole would leak urine all the time because it does not have a valve, it is just a puncture hole. Also, because the suprapubic puncture hole does not have any intestine to keep the tract between the skin and the bladder open, the hole will scar shut within a day if the catheter is removed.
In some cases the bladder cannot be saved with augmentation surgery. Some bladders are so small and scarred (or shriveled up) that bladder augmentation is not practical. Also, other people may have problems like fistula out of the bladder, tumors in the bladder or radiation damage that is so severe that the bladder is not suitable to be used for reconstruction. In these cases the bladder needs to be bypassed and people need to undergo urinary diversion. Finally, because bladder augmentation requires intermittent catheterization and a urinary diversion does not, some people who cannot do intermittent catheterization may opt for a urinary diversion. There are many types of urinary diversion that range from creation of a new bladder out of a sphere of bowel to creation of a simple conduit (or chute) to conduct urine from the kidneys to an intestinal stoma at the skin.