Rigi10™ Malleable Penile Prosthesis
Also Known As
Artificial Urethral Sphincter, AUS device, Implantable Urinary Sphincter
Definition
An Artificial Urinary Sphincter (AUS) is an implantable medical device designed to treat urinary incontinence, particularly stress urinary incontinence, by mimicking the function of the natural urinary sphincter.¹˒² It is a multi-component system, most commonly consisting of three parts: a urethral cuff, a pressure-regulating balloon, and a control pump.³
The urethral cuff is placed around the urethra and, when filled with fluid, compresses the urethra to prevent urine leakage.¹˒²˒³ The pressure-regulating balloon is typically implanted in the abdomen and maintains a set pressure within the system, ensuring the cuff remains effectively closed.¹˒²˒³ The control pump is usually placed in the scrotum (in males) or labia (in females) and allows the patient to manually operate the device.¹˒²
To urinate, the patient squeezes the pump, which moves fluid from the urethral cuff to the balloon.¹˒² This deflates the cuff, releasing the pressure on the urethra and allowing urine to flow. After a few minutes, the fluid automatically returns from the balloon to the cuff, re-establishing continence.¹˒² The primary purpose of the AUS is to restore urinary control and improve the quality of life for individuals with significant urinary incontinence that has not responded to other treatments.¹˒³
Clinical Context
The Artificial Urinary Sphincter (AUS) is primarily used to treat moderate to severe stress urinary incontinence (SUI), most commonly in men following prostate surgery (e.g., radical prostatectomy) or radiation therapy to the prostate, which can damage the natural urinary sphincter.¹˒²˒³ It is considered a gold standard treatment when conservative measures like pelvic floor exercises, lifestyle changes, or medications have proven insufficient.¹˒³
Patient selection criteria typically involve individuals with persistent SUI who are bothered by their leakage and are suitable candidates for surgery. Factors such as the severity of incontinence, previous treatments, patient dexterity (to operate the pump), cognitive function, and overall health status are considered.³ Patients with a history of urethral stricture, prior pelvic radiation, or previous urethral surgery may be at higher risk for complications and require careful evaluation.³
The surgical implantation of an AUS involves placing the three components (cuff, balloon, pump) through small incisions, often one in the perineum (between the scrotum and anus) for the cuff and pump, and another in the lower abdomen for the balloon.² The device is typically left deactivated for several weeks (commonly 6-8 weeks) after surgery to allow for healing before it is activated for use.²
Expected outcomes are generally positive, with high rates of patient satisfaction and significant improvement in continence.³ Studies, such as the MASTER trial, have reported continence rates around 84% following AUS placement, with over 90% of men satisfied with their continence and willing to recommend the procedure to others with similar symptoms.³ However, potential complications can occur, including infection, erosion of the cuff into the urethra, mechanical failure of the device, pain, bleeding, or persistent incontinence.¹˒²˒³ The device may also wear out over time, typically lasting 8-10 years, and may require revision or replacement surgery.¹˒²