Urinary Sphincter: What You Need To Know About It

Jessica Lubahn 3 min read

Urinary Sphincter

The urethral sphincter is a muscle that is responsible for regulating the outflow of urine from the bladder into the urethra. In simple words, it is a muscle that plays an important role in releasing urine out of your bladder.

The Functioning of the Urethral Sphincter

When the urinary sphincter is contracted, the opening of the bladder is blocked to stop leakage of urine. In order to urinate, the urinary sphincter is relaxed which opens the blockage making urine flow out of the body. This muscle is found in between the bladder and urethra.

However, there are people who face the problem of not being able to control their urinary sphincter which leads to involuntary urine leakage. This is also known as urinary retention or incontinence. The reason behind this can be a nerve or muscle damage either in the urethra or the bladder.

Causes of Urethral Sphincter Nerve or Muscle Damage

The reasons behind urethral sphincter damage can be some sort of stress or trauma that happened to the pelvic floor, bladder or urethra. There can be multiple reasons behind this from childbirth to surgery or spinal cord injuries. While some damages happen to be temporary, others can turn out to be permanent.

Functioning of the Urethral Sphincter after Nerve or Muscle Damage

Due to the damages in the nerve or muscle, the urethral sphincter fails to block the bladder to retain urine. This condition is also known as intrinsic sphincter deficiency or ISD. The excessive scarring of the urethra or nerve damage leads to a reduction in blood supplies to the bladder neck and proximal urethra.

Treatment: Artificial Urinary Sphincter

Artificial Urinary Sphincter

In order to control the intrinsic sphincter deficiency or urine leakage, a device called an artificial urinary sphincter is surgically installed in the body. The surgery requires a few small incisions in the lower part of the abdomen.

The AUS device is made up of three parts i.e. Urethral Cuff, Pump, and Balloon.

The urethral cuff is wrapped around the urethra in order to control urine. Acting like the urethral sphincter, it does not let any urine pass when the cuff is closed whereas the urine can easily pass through when the cuff is open.

The pump is placed in the scrotum for men and in the labia for women. It is responsible for moving fluids into or away from the urethral cuff by squeezing it to inflate or deflate the cuff.

The balloon or the reservoir is what holds the fluid as the cuff. When the urethral cuff is opened or deflated, the fluid is moved to the balloon. This is installed under the abdominal muscles or lower tummy.

In order to urinate with the artificial urinary sphincter device, one must squeeze the pump in the scrotum or the labia. The fluid from the urethral cuff is moved to the balloon or reservoir with the help of this pump. When the cuff opens, it opens up the urethra which stays open for about three minutes allowing you to urinate and it closes automatically.

Post-surgery once the tissues are healed in about four to six weeks, the system is activated. It needs manual dexterity because the pump needs to be pressed manually every time. This might feel weird in the beginning but the patients tend to get habitual of it pretty soon.