Rigi10™ Malleable Penile Prosthesis
Also Known As
AUS pressure, urethral occlusive pressure, sphincter cuff pressure, PRB pressure, artificial sphincter pressure
Definition
Cuff pressure refers to the pressure maintained by an artificial urinary sphincter (AUS) cuff, a medical device component that surrounds the urethra and exerts controlled compression to prevent involuntary urine leakage.¹ This pressure is generated by a fluid-filled system and regulated by a pressure-regulating balloon (PRB) implanted in the patient’s lower abdomen.² The cuff pressure is carefully calibrated to provide sufficient urethral compression to maintain continence while minimizing the risk of urethral tissue damage or erosion.³ Measured in centimeters of water (cmH₂O), typical cuff pressure ranges from 41 to 90 cmH₂O, with most patients requiring pressures between 51-70 cmH₂O for optimal function.⁴ The pressure can be temporarily released via a pump mechanism when the patient wishes to void, allowing the cuff to deflate and urine to pass through the urethra.⁵
Clinical Context
Cuff pressure is a critical parameter in the management of stress urinary incontinence (SUI) using artificial urinary sphincter devices, particularly in male patients following radical prostatectomy or other prostate surgeries that may damage the external urethral sphincter.¹ The selection of appropriate cuff pressure is individualized based on the severity of incontinence, urethral condition, and patient-specific risk factors.²
Patient selection criteria for AUS implantation with optimized cuff pressure include demonstrated intrinsic sphincter deficiency, adequate manual dexterity to operate the pump mechanism, and absence of active urinary tract infections or significant bladder dysfunction.³ Patients with certain urethral risk factors (e.g., prior pelvic radiation, previous urethroplasty, or prior AUS erosion) may benefit from lower cuff pressures (e.g., 51-60 cmH₂O) to minimize complications like urethral erosion.⁴
The surgical procedure involves placing the inflatable cuff around the bulbar urethra, with the pressure-regulating balloon implanted in the prevesical space or a high submuscular location in the abdominal wall.² The cuff size is carefully measured, with sizes ranging from 3.5 to 11 cm in half-centimeter increments, with 4 cm being most commonly used in men.² The pressure-regulating balloon is available in 5 ranges of water pressure: 41-50, 51-60, 61-70, 71-80, and 81-90 cmH₂O, with selection based on the lowest pressure necessary for urethral closure.²
Expected outcomes include high success rates in restoring urinary continence, with many patients achieving social continence (0-1 pad per day).⁵ However, complications related to cuff pressure can include urethral erosion (3.8-10%), mechanical failure (approximately 12% at 4 years), and urethral atrophy due to chronic compression.³ Newer devices with adjustable cuff pressure mechanisms are being developed to allow post-implantation pressure adjustments without additional surgery, potentially improving long-term outcomes.⁴