Posts Tagged ‘Boston Scientic’

Artificial Urinary Sphincter (AUS): What You Need To Know

May 12, 2018

Andrew Siegel MD   5/12/2018

Severe involuntary leakage of urine following prostate surgery is a rare event, occurring in less than 5% of men following prostatectomy for prostate cancer, and in an even smaller percentage of men who have undergone prostate surgery for a benign process.  Following prostatectomy, it most often results from scarring of the bladder neck sphincter.  Severe incontinence can be devastating to one’s quality of life, affecting psychological, emotional, and sexual well-being and often causing loss of self-esteem, depression, and avoiding a healthy, productive, and active lifestyle.

Fortunately, for the small percentage of men rendered severely incontinent after prostatectomy, the AUS offers a great opportunity for cure and in significantly improving quality of life. It functions as a mechanical compression device of the urethra that is under the patient’s control, providing simple and discreet control over bladder storage and emptying.  Implanted entirely within the body, the device mimics the function of a healthy sphincter muscle by keeping the urethra closed until the patient desires to urinate.

The AUS prosthesis is a saline fluid-filled device composed of solid silicone elastomer consisting of three interconnected components: a cuff implanted around the urethra, a pressure-regulating balloon reservoir implanted behind the pubic bone, adjacent to the bladder, and a control pump implanted in the scrotum.  The cuff gently squeezes the urethra closed, preventing urine from passing.  When one wants to urinate, he simply squeezes and releases the control pump that is situated in the scrotum, temporarily transferring fluid from the cuff to the pressure regulating balloon.  The cuff opens, allowing urine to flow through the urethra.  Within several minutes, the pressure regulating balloon automatically returns the fluid to the cuff to once again pinch the urethra closed.

Blausen_0059_ArtificialUrinarySphincter

The AUS, first developed in 1972, has been used successfully for over 45 years and has been implanted in more than 150,000 men. Over the years, biomedical engineering refinements have further improved the AUS.  About two thirds of men will be completely continent after an AUS implant, and the other one third will experience only minor incontinence, requiring one or two small pads per day. The overall patient satisfaction rate exceeds 90%.

In order to be an appropriate candidate for the AUS, incontinence needs to be on the basis of a weakened or damaged sphincter and not due to bladder over-activity.  Additionally,  bladder capacity needs to be adequate and urinary flow rate sufficient to empty the bladder. The incontinence should be present for a minimum of 6 months before considering the AUS, since spontaneous improvement occurs for some time after prostatectomy. One obviously need to be sufficiently motivated to receive an implant, and its use demands manual dexterity in order to operate the control pump.

Implantation of the Artificial Urinary Sphincter

Implantation of the AUS is a one hour or so outpatient surgical procedure done under anesthesia.  The conventional operation is performed with one’s legs in stirrups and requires one incision in the abdomen and the other in the perineum (area between scrotum and anus).  In 2003, Dr. Steve Wilson and I devised an innovative technique for AUS implantation via a single scrotal incision. The advantages of the scrotal technique are a single incision, the fact that it can be done supine (lying on one’s back versus legs up in stirrups), faster operative time, ease of doing the procedure and decreased patient discomfort.  In either case, the control pump is one-size fits all, but the cuff is precisely measured to your anatomy and the pressure-regulating balloon reservoir is usually chosen to be 61-70 cm water pressure.

It is important to know that the AUS will not be activated– and thus will not be functional– for about a 6-week period of time to allow for healing of tissues. Activation is a simple process that is done in the office, involving minimal discomfort.

It is advisable to order and wear a MedicAlert bracelet (www.medicalert.org) to inform health care personnel that you have an AUS implant in the event of a medical emergency. If you were rendered unconscious or unable to communicate, this bracelet will inform emergency medical staff that you have an AUS, because if there is ever a need for a urethral catheter, it is imperative that the AUS be deactivated prior to catheter placement in order to avoid damaging the urethra.

FAQ

Who manufactures the AUS?

American Medical Systems Men’s Health Division of Boston Scientific, Inc. http://www.BostonScientific.com

Will insurance cover the AUS?

Medicare has a coverage policy for incontinence control devices, which includes the AUS.  Most commercial health insurers also cover the AUS when deemed medically necessary for the patient.

How effective is the AUS?

More than 90% of patients with the AUS have greatly improved continence, many of whom achieve complete urinary control with no need for pads and the remainder of whom have occasional, minor stress incontinence with vigorous activities, typically requiring one or two small pads per day.  The 61-70 cm pressure regulating balloon provides 61-70 cm of pressure around the urethra, which is sufficient closure for most of the activities of daily living.

Does the AUS need to be measured to my body?

The control pump is “one size fits all”, but the cuff is sized to the circumference of your urethra to achieve a proper fit.  The reservoir comes in a variety of pressures.  The higher the pressure of the reservoir, the tighter the closure of the urethra. The tighter the closure of the urethra, the better is the continence, but also the greater the chance of urethral damage from the higher pressures. A balance must be achieved in order to achieve the necessary pressure to achieve continence while minimizing potential damage to the urethra. In practical terms, this translates into a 61-70 cm. pressure reservoir for most men.

Can I have an AUS if I underwent surgery followed by radiation therapy?

Yes, but radiation therapy increases the  potential risk for complications because of tissue damage, scarring, decreased blood flow and less optimal wound healing.

What are alternatives to the AUS, assuming that behavioral techniques and pelvic floor muscle exercises have failed?

  1. Absorbent pads and garments
  2. Penile compression clamps
  3. External collecting devices
  4. Urethral bulking agents
  5. The male sling

The first three are external, bulky, mechanical means of coping with–not treating–the problem.  Urethral bulking agents have fared poorly and the male sling is a possibility, although it is indicated for lesser degrees of incontinence and achieves results far inferior to those possible with the AUS.

Who should not have an AUS prosthesis?

The AUS is not appropriate for a man with an obstructed lower urinary tract. It also should not be used for those with bladder-related incontinence (overactive bladder or a small-capacity, scarred bladder) as it is indicated only for those with sphincter-related incontinence. It cannot be effectively used in those with compromised dexterity or mental acuity.

What are the potential risks and complications associated with AUS implantation?

Infection   As with any surgery, an infection can develop after an AUS implant.  Every step is taken to reduce the likelihood of an infection, including intravenous antibiotics, an antiseptic scrub of the surgical site on the operating table followed by the application of an chlorhexidine and alcohol skin antiseptic immediately prior to the operation, double-gloving, meticulous surgical technique with the procedure done as quickly as possible, topical antibiotics to flush the surgical site, and minimizing operating room traffic. Antibiotic ointment is placed on the surgical incision prior to placing the surgical dressing. Patients are sent home with oral antibiotics.

Two of the three components of the AUS–the cuff and pump–are coated with an antibiotic combination called InhibiZone, which consists of rifampin and minocycline.  If an infection occurs and does not respond to antibiotics, it may be necessary to remove the AUS, an extremely rare occurrence.

MH AMS 800 urinary sphincter product

Image above: AUS with inhibiZone coating of control pump and cuff

 

Erosion   This is a breakdown of the urethral tissues that lie beneath the cuff.   It is generally treated with cuff removal to allow for urethral healing prior to consideration for cuff replacement at a later date.  Erosion can occur when a catheter is placed into the urinary bladder by health care personnel uninformed that the AUS device is in place. The delicate urethra, pinched closed by the inflated cuff surrounding it, is traumatized and damaged by catheter placement.  This situation can be avoided by deactivating the AUS prior to catheterization.  This is one of the reasons that a MedicAlert card and bracelet are useful considerations. Erosion of the other AUS components can also occur on a rare basis. The control pump can potentially erode through the scrotal skin and the pressure-regulating balloon reservoir into the urinary bladder.

Mechanical Malfunction   The AUS is effective and reliable, but it is a mechanical device that can ultimately malfunction. It is not possible to predict how long an AUS will function in an individual patient.  As with any biomedical prosthesis, this device is subject to wear, component disconnection, component leakage, and other mechanical problems that may lead to the device not functioning as intended and may ultimately require additional surgery to replace the device. The median durability of the device is about 7.5 years, although I have patients who still have a functional AUS 20 years after implantation.

Urethral Tissue Atrophy   This can result from the long-term pressure effect of the cuff on the urethra.  Essentially, the urethra shrinks down from being squeezed by the cuff, resulting in worsening of urinary control.  When this happens, it generally requires repositioning of the cuff to a new urethral location or the use of a smaller cuff or, on rare occasion, placement of a second cuff (tandem cuff).

Pain    Discomfort in the groin, penis, and scrotum is expected immediately after surgery and during the period when the device is first used. It is very rare to experience chronic pain from an implantation of an AUS.

Migration and Extrusion  Migration is the movement or displacement of components within the body space in which they were originally implanted.  Extrusion occurs when a component moves to an abnormal location outside of the body.  These are both extremely rare occurrences

Bottom Line: The artificial urinary sphincter (AUS) is an effective, safe and reliable implantable medical prosthesis to restore urinary control in men with severe, refractory stress urinary incontinence.  Although there is no means of totally replacing our natural sphincter system, the AUS is the only device that simulates normal sphincter function by opening and closing the urethra at the will of the patient. It provides consistent results in the treatment of incontinence following prostatectomy and is considered to be the “gold standard” in the management of this problem. Many patients report that the AUS is nothing short of “life changing,” converting men who are bladder “cripples” back to normal function and restoring their quality of life. 

Wishing you the best of health,

2014-04-23 20:16:29

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Dr. Andrew Siegel is a physician and urological surgeon who is board-certified in urology as well as in female pelvic medicine and reconstructive surgery.  He is an Assistant Clinical Professor of Surgery at the Rutgers-New Jersey Medical School and is a Castle Connolly Top Doctor New York Metro Area, Inside Jersey Top Doctor and Inside Jersey Top Doctor for Women’s Health. His mission is to “bridge the gap” between the public and the medical community.

Dr. Siegel has authored the following books that are available on Amazon, iBooks, Nook and Kobo:

MALE PELVIC FITNESS: Optimizing Sexual & Urinary Health

THE KEGEL FIX: Recharging Female Pelvic, Sexual and Urinary Health 

PROMISCUOUS EATING: Understanding and Ending Our Self-Destructive Relationship with Food

These books are written for educated and discerning men and women who care about health, well-being, fitness and nutrition and enjoy feeling confident and strong.

Dr. Siegel is co-creator of the male pelvic floor exercise instructional DVD (female version is in the works): PelvicRx

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