Health

Spinal Cord Injury Secondary Condition: Bladder Management

Bladder management after a spinal cord injury is important to maintain quality of life and to maximize life expectancy. To accomplish ideal bladder management, it is necessary to understand the anatomy of the bladder and how it functions before and after a spinal cord injury. If this information is understood and management and follow-up are appropriate, then complications that may interfere with life can be eliminated or greatly reduced.

Anatomy
When discussing the anatomy of the bladder, we must also mention the kidneys and the connection between these two structures. Discussion of the urinary system is often divided into two parts. 

The first part, the “upper urinary tract,” includes the kidneys, the ureters and the ureterovesical junction. The kidneys are two bean-shaped organs located on each side of the spine in the back part of the abdomen. The role of the kidney is to filter waste matererial from the bloodstream and excrete (get rid of) it from the body through urine. Once the waste product (urine) is separated in the kidney, it travels down the ureter (the tube between the kidney and the bladder) to the bladder and waits for the appropriate time of urination as determined by the person. The ureterovesical junction (UVJ) is the area where the ureter enters into the bladder wall. This is a very important area because it acts as a “one-way valve.” The ureter enters the bladder wall at an angle so that as the bladder fills with urine it begins to compress this entry location. This helps to prevent urine in the bladder from traveling up the ureter to the kidney as it begins to fill (approximately 500 mL).

The other part of the urinary system is the “lower urinary tract,” which includes the bladder, sphincter and urethra. The bladder is divided into two areas: the detrusor and trigone. The detrusor (the top part of the bladder) is made up of crisscrossing muscle fibers. The trigone (the lower part of the bladder) is often referred to as the bladder neck. The sphincter is further divided into the internal and external sphincter. The internal sphincter is the junction between the bladder and the urethra; it is made up of circular muscles that are not controlled voluntarily. The external sphincter is under voluntary control; it is that muscle you squeeze tight when you have a full bladder and are trying to delay urination. It is also the muscle that you relax when it is time to urinate. The urethra is a tube that connects the bladder to the outside.

Nervous system control of the bladder
The bladder is controlled by the autonomic nervous system and the voluntary component of the nervous system. The autonomic nervous system control is further divided into the parasympathetic and sympathetic nervous system (see previous description of the autonomic nervous system under the main anatomy section).

The parasympathetic supply to the bladder arises from the spinal cord in the sacral region at S2-4. The parasympathetic control of the bladder causes bladder contraction. The sympathetic supply to the bladder arises from the spinal cord at the level of T11-L2. Sympathetic nervous system stimulation causes relaxation of the bladder and contraction of the bladder neck, both of which help to maintain the storage of urine within the bladder. The external sphincter is under voluntary control by the patient and is controlled by the pudendal nerve which arises from the spinal cord at S1-4.

Normal (prior to SCI) voiding (emptying the bladder) of urine
Normally there is a very coordinated response of the nervous system to control a fairly complex process of emptying the bladder. In the resting phase, when the bladder is filling with urine, the sympathetic nervous system continues to stimulate the bladder and causes relaxation of the bladder and contraction of the internal sphincter or bladder neck. When it is time to empty the bladder, the sympathetic nervous system stimulation is decreased and the parasympathetic nervous system then causes contraction of the bladder. At this time the person's brain also tells the external sphincter to relax, allowing urine to flow out.

Voiding of urine after spinal cord injury
Not all spinal cord injuries result in voiding patterns that are identical. The first question that needs to be asked is,

“Is this an upper motor neuron injury or a lower motor neuron injury?”
Usually, spinal cord injuries at T12 and above result in an upper motor neuron condition of the bladder. Spinal cord injuries at L1-L2 and below often result in a lower motor neuron condition of the bladder. This is a generalization regarding the specific level, and exceptions do exist. For example, the fractured vertebrae and injured spinal cord may have occurred at T12, but swelling and secondary injury may have caused the injury to progress downward to affect a lower level, resulting in a lower motor neuron condition of the bladder.

Upper motor neuron bladder (usually T12 and above): this condition is associated with uninhibited or spontaneous bladder contractions. When the bladder contracts, the bladder neck and sphincter do not relax as it does during normal urination. The condition where the bladder and sphincter are not in sync and actually oppose each other is called Detrusor External Sphincter Dyssynergia (DESD). This has been shown to occur in 96% of all patients with an upper motor neuron bladder. This condition of DESD can lead to excessively high pressures within the bladder, which can further lead to an abnormal structure of the bladder wall. This abnormal structure and high pressures can eventually lead to a dangerous complication of reflux of urine from the bladder up toward the kidneys. This reflux increases the pressure on the kidney and it can seriously damage them.

Long-term management is focused on eliminating DESD and lowering the pressures that are in the bladder to prevent deterioration of the bladder wall structure and reflux of urine up towards the kidney. This is accomplished and very successful with various interventions with drainage techniques and/or medications described below.

Lower motor neuron bladder (usually L1 and below): this condition is associated with a bladder that does not contract. Management is focused on preventing overdistention and urinary tract infections.

Management Options

Upper Motor Neuron Bladder

Drainage method options:
Intermittent Catheterization (IC)
This method to drain the bladder is preferred in individuals who have appropriate finger dexterity and no other reasons why they cannot perform IC such as strictures or scar tissue and autonomic dysreflexia. Intermittent catheterization is a process of inserting a small tube through the urethra into the bladder to allow urine to drain freely. Once urine has completely drained from the bladder, the catheter is removed. This process is repeated every four to six hours or as needed to prevent the volume within the bladder exceeding 400-500 mL. This usually requires a fluid restriction of 2 Liters per day. The procedure of intermittent catheterization is performed with sterile technique while in the hospital. Many individuals change to a “clean” technique once they leave the hospital. Clean intermittent catheterization (CIC) requires cleaning and reusing catheters and washing hands, but gloves are usually not used. Another option is using catheters that are enclosed within a bag or sheath to allow individuals to perform sterile catheterization without adhering to sterile technique. Insurance companies and Medicare often require documentation of multiple urinary tract infections before they will pay for or reimburse the use of “close system” catheters. Most of these close system catheters have incorporated an introducer tip that has been shown to decrease urinary tract infections. It does this by bypassing the first 1 cm of the urethra that contained the highest level of bacteria concentration. Therefore, this introducer tip is reported to be able to decrease the amount of bacteria being pushed into the bladder which can lead to a reduction in infection. Intermittent catheterization often requires the use of medication to prevent spontaneous bladder contractions in-between catheterizations.
 
Reflex Voiding
This is a method that is usually only used by men. Reflex voiding occurs when the bladder is able to spontaneously contract with enough force to cause urine to be evacuated from the bladder and out through the penis. This method of bladder management requires the use of an external (condom) catheter which is attached to a leg bag during the day and larger bedside bag at night. To use this technique it is crucial to identify whether detrusor external sphincter dyssynergia (DESD) is present and if the pressures within the bladder are elevated. In these conditions exist, reflex voiding cannot be used because it will cause long-term damage to the bladder and potential harm to the kidneys. Reflex voiding usually requires the use of medications to decrease sphincter activity, which decreases the resistance of urine exiting the bladder.

Foley (Indwelling) Catheter
A Foley catheter is similar to an intermittent catheter but it has a small balloon on the end of the catheter that goes into the bladder. This balloon is inflated with sterile water via a separate port once it is in the bladder. Foley catheters are meant to stay in the bladder for prolonged periods of time. They are often changed every two to four weeks. This type of bladder management is often preferred for patients who cannot perform intermittent catheterization because of limited finger dexterity or other physical reasons why a catheter cannot be inserted several times a day. It is also used for individuals who cannot keep an external (condom) catheter on the penis.

There are several complications that can occur with the use of a Foley catheter. Individuals can develop increase urinary tract infections, bladder stones and erosions through the urethra, which can cause a tunnel from the urethra to the scrotum (called a fistula)in men. Spontaneous bladder contractions can still lead to an increase in bladder pressure which may result in automomic dysreflexia. It is recommended that individuals who have a long-term Foley catheter in place take a medication to relax the bladder and prevent these contractions. It has been shown that individuals who have a Foley catheter in place for greater then 10 years have an increased rate of bladder cancer. Therefore, routine annual screening is recommended by some urologists who specialize in spinal cord injury.

Suprapubic catheter
This has the same indications for use as the indwelling (Foley) catheter. A suprapubic catheter is described by the method in which the catheter enters the bladder. A Foley catheter is used, but it enters the bladder through the lower abdominal wall. A small surgical hole is created through the lower abdominal wall just above the bladder. A suprapubic catheter is beneficial in that it does not lead to erosions of the urethra or epididymitis (an infection of a part of the testicle). All other risk factors are similar to the indwelling (Foley) catheter and follow up is identical. Another benefit of the suprapubic catheter in both males and females is that it is more convenient for sexual activity than an indwelling (Foley) catheter. In females the suprapubic catheter is less likely to lead to contamination of the bladder with bacteria from the vagina and fecal material because it is not ever in this location.

External (condom) catheter
Condom catheters are used exclusively in men. This device is similar to a condom used for conception prophylaxis during sexual intercourse except that the tip of the catheter is open and attaches to a tube and drainage bag. There have been many versions and improvements of condom catheters over the years. Most catheters in use today have a self-adhesive material lining the inside of the condom catheter. This helps the condom to maintain the proper position on the penis throughout the day. Prior to the use of this self-adhesive material, condom catheters were kept in place by a foam adhesive strap that was wrapped around the base of the condom and penis. Condom catheters with this type of securing device are still available today but used much less frequently. In addition to the self-adhesive material lining the inside of the condom catheter, Skin Prep is often used prior to donning the condom catheter. Skin Prep is a pad that is similar to an alcohol pad, but it contains a solution that becomes sticky once applied to the penis before the condom catheter is applied. Condom catheters should be changed every day to help prevent urinary tract infections and to perform skin evaluation to prevent breakdown.

Commonly used medications
Anticholinergics
• Prevents bladder contractions
• Used in intermittent catheterization to prevent contraction of the bladder between catheterizations
• Used in indwelling and suprapubic catheters to prevent permanent shrinkage of the bladder down around the indwelling catheter balloon.

Examples: Ditropan, Detrol

Alpha-blockers
• Opens the bladder neck
• Used with reflex voiding management method.

Examples: Flomax, Hytrin, Cardura

Infection Prevention
• Goal is to prevent Urinary Tract Infections (UTI)

Methenamine: becomes formaldehyde in the bladder
Cranberry pills: controversial
Antibiotics: avoid the use of long-term antibiotics in the prevention of urinary tract infections.  Long-term use can create the development of multi-resistant bacteria, or “super bugs” that will not respond to treatment with any antibiotics.

Surgical Interventions
Sphincterotomy is a procedure where a cut is made through the external urinary sphincter and the bladder neck. This procedure is performed only in men with upper motor neuron bladders. After this procedure is performed, the patient is committed to wearing a condom catheter for life. The bladder does fill up and contract, and urine exits through the penis and condom catheter into a leg bag. This procedure is done to prevent detrusor external sphincter dyssynergia (DESD) and maintains low pressure in the bladder, which helps to preserve the long-term function of the kidneys.

A sphincterotomy is often used in individuals with limited hand dexterity who cannot or do not want to perform intermittent catheterization and who elect not to use an indwelling or suprapubic catheter.

Bladder augmentation is a surgical procedure that usually uses a part of the gastrointestinal tract. Part of the gastrointestinal tract is removed and made into a bladder by sewing it into the present bladder. Bladder augmentation is used for individuals who have a bladder with a low compliance (small bladder that does not expand easily when filling), autonomic dysreflexia or severe bladder contractions.

Urinary diversions are usually divided into two groups, referred to as non-continent and continent diversions.

A common non-continent diversion is called an ileal conduit. With this surgical procedure, approximately 10 cm of the ileum (part of the small intestine) is cut out. One end is attached to the abdominal wall and the other end is closed off. The ureters are then attached to the ileal conduit so that the urine drains from the kidneys to the ileal conduit instead of the bladder.

A common continent diversion is called an orthotopic diversion. This surgical procedure is similar to the bladder augmentation where a part of the gastrointestinal tract is used. It is different in that the pouch directly attaches to the urethra and can be catheterized. The area between the urethra and the pouch must have a surgically created continent valve.

Lower Motor Neuron Bladder

Lower motor neuron bladders are not expected to be able to contract. In addition, some lower motor neuron bladders can develop a decrease in bladder compliance, which prevents it from expanding and adjusting to a larger volume of urine within the bladder. If this condition does occur, it increases the pressure within the bladder and can lead to deterioration of the bladder wall and upper tracts. In this case a urologist may recommend the addition of an alpha-blocker medication or a bladder augmentation surgery. Some bladders also leak urine because of a weak external sphincter. This often occurs when straining or bending over. Therefore it is often recommended to empty the bladder before it becomes distended or full of urine.

The most commonly recommended method of bladder drainage is intermittent catheterization. 

Some individuals are able to perform a Crede or valsalva maneuver to empty the bladder. The Crede maneuver involves physically pushing down on the bladder with the hand to empty the bladder. Valsalva is a process of increasing the pressure within the abdomen by bearing down as if trying to push out stool during a bowel movement. Individuals who use Crede or valsalva must be certain that there is no evidence of detrusor external sphincter dyssynergia (DESD) to prevent deterioration or failure of the upper tracts and kidneys. Urodynamics testing can determine if pressures within the bladder are excessively high during a Crede or valsalva maneuver.
 
In some cases individuals with lower motor neuron bladders will use an indwelling catheter.

Follow-up
Lifelong follow-up of bladder and kidney function is crucial to maximizing health in the spinal cord injured patient. The exact time of follow-up and procedures performed will depend on each individual's circumstance and their managing physician. At a minimum, the spinal cord injured patient should have annual blood tests performed to follow the level of creatinine of the blood. Creatinine rises when kidney function begins to deteriorate. Another way to measure creatinine is by collection a urine sample for 24 hours.

Urodynamics is a diagnostic test that monitors the pressure in the bladder and the presence or absence of detrusor external sphincter dyssynergia (DESD). 

A cystogram is a procedure where contrast dye is injected into the bladder through a catheter and an x-ray is then taken of the bladder, ureter and kidneys. This x-ray will show the shape and size of the bladder and most importantly if reflux is present. Reflux can be seen as the contrast dye in the bladder is traveling up the ureter towards the kidneys.

A cystometrogram (CMG) is often performed as part of urodynamics. In this procedure a catheter is inserted into the bladder and filled slowly with water or carbon dioxide. This is used to show how the bladder functions as it is filled with urine. During this test, pressures within the bladder are measured as well as the specific volumes at which the bladder begins to contract.

Ultrasound can be used to evaluate the kidneys and ureters. It can often be used to identify hydronephrosis, which is a dilation of the ureter that occurs with reflux. Ultrasound can also identify stones that may be present.

Renal scan is a test that measures kidney function. A radioisotope is injected into a vein,which then flows through the kidney. Multiple pictures are taken of the kidneys over a period of 30 minutes to one hour and interpreted by a computer. Renal scans can determine the function of the kidney by how well it is able to filter the blood.