All Products
Also known as
AUS Control Pump Failure, Artificial Urinary Sphincter Pump Dysfunction, AUS Device Malfunction, Urinary Sphincter Pump Failure, AUS Mechanical Failure, Control Pump Dysfunction
Definition
AUS Pump Malfunction refers to the failure in the mechanical operation of the artificial urinary sphincter pump component, which can lead to difficulties in inflating or deflating the cuff.1 This malfunction disrupts the normal function of the device, potentially resulting in either persistent urinary incontinence or urinary retention.2 The pump component, typically placed in the scrotum in males or labia majora in females, is designed to allow manual control of the fluid transfer between the pressure-regulating balloon and the urethral cuff.3 When functioning properly, this system enables patients to control urination by temporarily deflating the cuff. Mechanical failures can occur due to various causes including component wear, fluid loss, pump migration, or physical damage to the device.1-3
The artificial urinary sphincter (AUS) is a multi-component system consisting of three main parts: a urethral cuff, a pressure-regulating balloon (PRB), 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.3 The PRB is typically implanted in the abdomen or pelvic region and maintains a set pressure within the system, ensuring the cuff remains effectively closed.3 The control pump allows the patient to manually operate the device by squeezing it to deflate the cuff, allowing urine to flow from the bladder to the urethra.3 After urination, the fluid automatically returns from the balloon to the cuff, re-establishing continence.3
Pump malfunction can manifest in several ways, including difficulty operating the pump, inability to inflate or deflate the cuff, or complete mechanical failure of the pump component.1-4 Research by Srivastava et al. found that while PRB malfunction was the most common cause of AUS failure, cuff or pump malfunction was relatively rare.1 However, when pump malfunction does occur, it can significantly impact the patient’s quality of life and may require surgical intervention to correct.1-4
Clinical Context
AUS Pump Malfunction is clinically relevant in the management of patients with implanted artificial urinary sphincters, which are primarily used to treat moderate to severe stress urinary incontinence (SUI).1 The AUS is considered the gold standard treatment for male SUI, particularly following prostate surgery (e.g., radical prostatectomy), radiation therapy, or other urologic procedures that can damage the natural urinary sphincter.1,3
Patient selection for AUS implantation typically involves individuals with persistent SUI who are bothered by their leakage and are suitable candidates for surgery.3 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.3 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.3
When AUS pump malfunction occurs, patients typically present with recurrent urinary incontinence after a period of successful control, difficulty operating the pump, inability to inflate or deflate the cuff, or urinary retention if the cuff cannot be deflated.1,2 Diagnosis involves physical examination of the device components, testing how the device cycles, cystourethroscopic evaluation, and assessment of the patient’s symptoms.1,3
Management of AUS pump malfunction depends on which component has failed. Research by Srivastava et al. found that pressure-regulating balloon (PRB) malfunction most commonly caused AUS failure, while cuff or pump malfunction was rare.1 For PRB malfunction, PRB-only correction may satisfactorily restore AUS function in select patients.1 In cases where the specific failing component can be determined preoperatively, just that component can be replaced; otherwise, the entire device often needs replacement.1,3
Expected outcomes following revision surgery for AUS pump malfunction are generally positive, with studies showing high rates of restored continence.1,2 However, patients should be counseled about the possibility of future device failures, as mechanical components may wear out over time, typically lasting 8-10 years.3 The MASTER trial demonstrated an 84% continence rate following AUS placement, with over 90% of men satisfied with their continence and willing to recommend the procedure to others with similar symptoms.3
Potential complications of AUS implantation and revision surgery include infection, erosion of the cuff into the urethra, mechanical failure of the device, pain, bleeding, or persistent incontinence.1,2,3 Careful patient selection, proper surgical technique, and regular follow-up are essential to minimize these risks and ensure optimal outcomes.