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Artificial Urinary Sphincter (AUS)

The artificial urinary sphincter is the gold-standard surgical treatment for moderate to severe male stress urinary incontinence — most often after radical prostatectomy or radiation. The AMS 800 (Boston Scientific) has been the dominant device for four decades.

Device Components​

Three silicone-based components connected by tubing:[1][2]

  1. Urethral cuff — wraps the bulbar urethra (male) or bladder neck (female / specific male anatomy); pressurized to maintain urethral closure
  2. Pressure-regulating balloon (reservoir) — placed in the space of Retzius; maintains constant pressure in the cuff
  3. Control pump — placed in the dependent scrotum (or labia majora in female); squeezed by the patient to open the cuff and permit voiding

Operation​

  • Patient squeezes the scrotal pump → fluid transfers from cuff to reservoir → urethra opens → patient voids
  • After ~90 seconds, fluid automatically returns from reservoir to cuff → urethra recloses
  • A deactivation button on the pump allows the device to be locked open during procedures or catheterization

AMS 800 — the Reference Device​

  • Cuff sizes: 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 9.0, 10.0, 11.0 cm — fitted to the measured circumference of the bulbar urethra
  • Pressure-regulating balloon: 61–70 cm H₂O (standard), 71–80 cm H₂O (higher pressure)
  • InhibiZone antibiotic coating option

Indications​

  • Male SUI after radical prostatectomy — the classic indication
  • Post-radiation SUI (higher complication rate but still often indicated)
  • Failed male sling (AdVance, AdVance XP)
  • Severe SUI (>2–3 pads per day typical threshold)
  • Female SUI in highly select cases (revision, complex)

Combined with IPP​

AUS and IPP can be implanted concurrently or in stages in post-prostatectomy patients with both SUI and ED. A single combined operation has not shown increased adverse events compared with single or staged implantation.[3]

Complications​

  • Mechanical failure — tubing kinks, pump dysfunction; typical device life 10+ years with revision often needed
  • Infection — 1–5%; higher in radiated patients
  • Erosion — cuff erosion into urethra is the most consequential complication; typically requires device explant
  • Atrophy — the urethra under chronic cuff pressure may thin over time, requiring cuff downsizing
  • Urethral stricture — at the cuff site

Emerging Devices​

Newer AUS designs under investigation — Flume, RigiCon, and others — aim to reduce mechanical failure and simplify patient operation, but none has displaced the AMS 800 as reference standard.

References​

1. Chorney ET, Ramchandani P, Jaffe WI, Siegelman ES. CT and MR Imaging Features of Artificial Urinary Sphincters, Penile Prostheses, and Other Devices in the Male Lower Genitourinary Tract. RadioGraphics. 2018;38(3):794–805. doi:10.1148/rg.2018170087

2. Chung AD, Aswani Y, Tsai LL. Imaging Review of Male Genitourinary Devices and Augmentations. European Journal of Radiology. 2026;199:112829. doi:10.1016/j.ejrad.2026.112829

3. Segal RL, Cabrini MR, Harris ED, et al. Combined Inflatable Penile Prosthesis–Artificial Urinary Sphincter Implantation: No Increased Risk of Adverse Events. Journal of Urology. 2013;190(6):2183–2188. doi:10.1016/j.juro.2013.06.084

See also: Inflatable Penile Prosthesis, Autologous Rectus Fascia.