Narrative patent review of penile clamp, artificial urinary sphincter, and sling innovation in the management of male stress urinary incontinence

Background and Objective: Stress urinary incontinence (SUI) is the involuntary loss of urine affecting 1-3% of the male population. To manage leakage, patients may try a plethora of penile clamps. and may even consider artificial urinary sphincters (AUS) or sling implantation. We aimed to synthesize the evolution of the modern clamp, AUS, and sling through a comprehensive patent search. Methods: Patents were found through the databases of United States Patent and Trademark Office (USPTO), GooglePatents, and the World Intellectual Property Office Patentscope, covering patents published through January 6, 2024. Key Content and Findings: We found 30 different patents (10 clamps, 13 AUS, and 7 slings), including the patents pertaining to the functionalities and design of five commercially available penile clamps, the American Medical System 800 (AMS 800), the InVance, AdVance, AdVance XP, and Virtue Slings. The clamps, spanning back to 1938 with Bard Cunningham's clamp, have undergone significant refinements. For example, inventors such as Edson S. Outwin and Juan F. V. Wiesner, have modified the location of the primary pressure point. Accessibility has also improved with inventors, such as Gerald French and John W. Timmons, fastening the clamps with Velcro (R), (R) , as opposed to the screw and ratchet catch closing mechanism, as in Cunningham's clamp. Similarly, the AUS has greatly evolved since Foley's 1947 "Artificial Sphincter and Method", which was the primary AUS precedent to Mark Polyak's AUS invention, which covered the essential elements and functionalities, such as the incorporation of a balloon reservoir, for the AMS 800. In addressing AUS limitations, inventors such as David W. Anderson and Louisa Thomas have created non-hydraulic AUSs. Likewise, the male sling has seen an evolution in the method of securement, from the use of fixed bone anchors in the InVance sling to the transobturator route used in the AdVance XP, avoiding bone complications. Additionally, innovation in sling adjustment of urethral compression allows for adjustable urethral elevation and distal compression respectively. Recent patents have claimed technological integration for clamps, AUS, and slings, especially concerning automation. Conclusions: Overall, patents have built upon the limitations of previous devices. However, there is still a need to innovate for increased clamp comfort and reduced reoperation rates for the AUS and sling.