A review article on urinary incontinence (UI) by Marziale et al. (2018) has made me aware that UI should be considered a global health issue. For instance, in 2013, 386 million people worldwide experienced involuntary urine leakage (Marziale et al., 2018). In general, one can distinguish between three key UI types, depending on the affected part of the urinary system. Firstly, stress urinary incontinence (SUI) is characterized by damage to the sphincter. Secondly, urge urinary incontinence (UUI) stems from damage to the bladder. Lastly, mixed urinary incontinence occurs due to damage to the sphincter and the bladder (Marziale et al., 2018). In all UI conditions, a person loses the ability to control the bladder and void urine voluntarily.
Furthermore, the urination process, also known as micturition, is closely related to the nervous system, which lets a person relax their external urethral sphincter voluntarily. Unlike the internal urethral sphincter, the external urethral sphincter is present in both sexes and consists of skeletal muscle encircling the urethra (Saladin, 2020). Normal bladder functioning and voiding require a highly coordinated contraction of sufficient duration and size (Weledji et al., 2019). This contraction becomes possible due to the relaxation of the pelvic floor and the external urethral sphincter initiated by the somatic inhibitory fibers of the pudendal nerve (Weledji et al., 2019). As such, the UI can also be caused by neurological disorders or extreme fear.
Given the significance of the external urethral sphincter for the urinary system’s functioning, one might wonder whether a solid medical solution for SUI and MUI exists. According to Marziale et al. (2018), the modern market offers various artificial urinary sphincter (AUS) models. However, significant drawbacks, such as tissue atrophy, erosions, infections, and high invasiveness, are commonly associated with these devices (Marziale et al., 2018). In this regard, the main challenge for the manufacturers lies in combining low invasiveness with an accurate simulation of the natural human sphincter. Due to the UI prevalence in the world, the search for a long-term medical solution should be pursued by the global healthcare and scientific communities.
Marziale, L., Lucarini, G., Mazzocchi, T., Gruppioni, E., Castellano, S., Davalli, A., Sacchetti, R., Pistolesi, D., Ricotti, L., & Menciassi, A. (2018). Artificial sphincters to manage urinary incontinence: A review. Artificial Organs, 42(9), E215-E233.
Saladin, K. S. (2020). Anatomy & physiology: The unity of form and function (9th ed.). McGraw Hill.
Weledji, E. P., Eyongeta, D., & Ngounou, E. (2019). The anatomy of urination: What every physician should know. Clinical Anatomy, 32(1), 60-67.