Artificial Urinary Sphincter Implantation and Its Application in Urinary Incontinence

Introduction:

Urine excretion is a physical procedure through which excess water and toxic byproducts are eliminated. The excretion of urine is a voluntary process that is developed in early childhood. This voluntary process is regulated by neurological control and organs like the urinary bladder and urethra. Any disturbance in this mechanism may cause accidental leakage of urine.

What Is Urinary Incontinence?

Sudden leakage of urine is known as urinary incontinence. This is a type of involuntary activity that is seen during various physical activities. This is most commonly seen in women. Different types of urinary inconsistency are seen based on several situations and pathological conditions.

Etiology:

The causative factors for urinary incontinence are:

• Stress Urinary Incontinence: This type of urinary inconsistency occurs due to a sudden increase in intra-abdominal pressure. Such things usually occur during coughing, sneezing, and exertion. This is also seen in sports persons during sports activity or in pregnant women. Persons can predict the leakage of urine. Urethral sphincter or pelvic floor weakness is the root cause of this type of urinary incontinence.

• Urge Urinary Incontinence: This type of urinary leakage is related to urinary urgency. Bladder dysfunctions are the root cause of this type of urinary incontinence. Increased bladder activity, bladder hypersensitivity, and poor detrusor compliance are responsible for such situations. Such type of incontinence is seen in elderly people.

• Mixed Urinary Incontinence: This type of urinary inconstancy occurs due to stress and urgency.

• Overflow Urinary Incontinence: This type of urinary inconsistency occurs due to an over-distended bladder or due to chronic urinary retention. Overproduction of urine in diseases like diabetes is one of the main reasons for this type of urinary incontinence. Over-distension of the bladder is another reason behind it. Bladder outlet obstruction is responsible for over-distension of the bladder. Such type of bladder outlet obstruction happens due to pathological factors like Skene's gland cyst (cyst in the Skene's gland which is located at the lower end of the urethra), presence of the Mullerian duct remnants, urethral diverticulum (presence of unwanted sac in the urethra), and ectopic ureterocele (presence of extra tube in the urinary system). Cervical carcinoma, vaginal cancer, and urethral carcinoma are also associated with bladder obstruction. One of the most common causes of this urinary incontinence is benign prostatic hyperplasia in males (overgrowth of prostate tissues) and pelvic prolapse (abnormal position of pelvic organs) in females.

• Functional Urinary Incontinence: Environmental factors or physical barriers to toileting are responsible for this type of urinary inconsistency. In such cases, the urinary tract functions normally, but physical or cognitive impairment causes urine leakage. Functional conditions like dysfunctional voiding and external sphincter pseudodyssynergia (unusual sphincter contraction during voiding) are also related. Neurological disorders like spinal cord injury, multiple sclerosis, degenerative changes in the pelvic floor muscles, and Parkinson's disease may also cause bladder obstruction.

What Are the Different Treatment Options?

Different treatment options for urinary incontinence are:

1. Low-dose estrogen can be applied to the vaginal wall, which can be helpful in improving blood supply and reducing the symptoms of lower urinary tract symptoms. Also, medications like anticholinergic drugs can be used, which are helpful in reducing voiding symptoms. Apart from this, drugs like alpha-adrenergic agonists (e.g., Phenylpropanolamine), beta 3-adrenergic receptor agonists (Mirabegron), and serotonin–noradrenaline reuptake inhibitors (Duloxetine) can be used for this condition.

2. Stress incontinence surgery can be performed in severe cases. Surgeries such as transurethral resection of the prostate (TURP) can be used for the removal of obstructions. Also, the application of electrical stimuli can be helpful. Rectal or vaginal probes are used for this purpose.

3. Exercises such as pelvic floor training exercises or Kegel exercises are beneficial. These exercises are responsible for strengthening the pelvic floor muscles and increasing the contractile ability of the muscles. Increased muscle contraction increases the pelvic floor's volume and lifts the levator plate. Stiffness due to the contraction of muscles is responsible for increased intraabdominal pressure.

What Is Artificial Urinary Sphincter?

The urinary bladder is a pear-shaped muscular organ of the body. The function of the urinary bladder is to store and release it when needed. These smooth muscles that maintain the urinary bladder's structural integrity are smooth muscles known as detrusor (bladder) muscles. The internal urethral sphincter is located at the junction of the urethra and urinary bladder. It is under the control of the autonomic nervous system and provides involuntary control of urinary flow. The external urethral sphincter is a striated skeletal muscle that provides voluntary control over urinary outflow.

Overactive bladder is a chronic disorder that is one of the main causes of urinary incontinence. This affects both men and women. Hyperactivity of the detrusor muscle is responsible for this.

The first hydraulic artificial urinary sphincter was developed in 1973 by Scot et al. This device was made up of silicon and divided into parts like a two-piece reservoir, inflatable cuff, two pumps, and resistors for inflation and deflation. The device is inflated for urinary retention when needed and prevents urine leakage. This process is aided by the cuff. The pump is placed in the scrotum and connected to the cuff. The patient activates or deactivates the device through it. The reservoir is placed in the abdomen and connected to all three parts. Furlow et al. redesigned the device in the 1980s. In this new device, a pressure-regulating balloon is attached. This balloon occludes the urethra at a defined pressure, and a pump helps in the deactivation mechanism through the scrotal skin.

How Is an Artificial Urinary Sphincter Placed?

The surgery is usually done under general anesthesia, but spinal anesthesia for the lower limb can also be used in such cases. The urinary bladder should be completely empty before the surgery.

• First, a catheter is placed from the urethra to the urinary bladder. This helps to feel the urethra during the surgical procedure.

• During the surgery, the patient is placed in a high lithotomy position with knees angled less than 90 degrees.

• An incision is given in the perianal area as this area provides access to the proximal, mid, and distal bulbar urethra.

• A sharp dissection is made to expose the urethra, and a cuff is placed. Usually, a single cuff is preferred to a double cuff.

• After placing the cuff pump is placed in the scrotum region. In cases of female patients, it is placed in the labia majora (the outer fold of the uvula). The reservoir is placed alongside the bladder.

The risk factors for such surgical procedures are:

1. Uncontrolled hypertension and coronary artery disease (disease of the blood vessels of the heart).

2. Bladder dysfunction (a problem associated with the urinary bladder) is caused by neurogenic causes.

3. Recurrent urinary tract infections.

4. Radiation therapy.

5. Urethral atrophy (thinning and drying of the vagina).

Conclusion:

Hyperactive bladder muscles and improper activity of the detrusor muscle are responsible for the malfunctioning of the urinary sphincter. This leads to the sudden leakage of urine. Artificial urinary sphincters prevent accidental leakage by maintaining bladder pressure. Patients can urinate according to their will with the use of one button placed in the scrotum.