Magnetoelastic Dynamic Midurethral Slings. - Project Summary Stress urinary incontinence (SUI) affects up to 40% of all women, leading to a substantial reduction in quality of life and annual costs of ~$10s bn in the United States. This condition is characterized by an undesired loss of urine during activity, such as exercise, sneezing, or coughing. Among the current surgical treatment options, the synthetic sub-urethral sling has gained wide popularity over the past 10-15 years. At present, sling materials (e.g., polypropylene) placed beneath the urethra are permanently fixed. This static behavior is a leading contributor to complications. Alternative SUI surgical treatments methods include artificial urinary sphincters, which are invasive devices that pump fluids between a reservoir and a cuff to achieve dynamic forces around the urethra. Due to this complexity and invasiveness, these devices are reserved as the last option to treat SUI. The goal of this work is to develop a novel, shape-changing sling which is minimally-invasively placed, supports and compresses the urethra to achieve continence, and can be activated to reduce the pressure on the urethra to enable complete voiding. This reduction in support would be triggered using a handheld device either placed above the urethra or inserted into the vagina in a tampon-like device. The assembled team is well qualified to answer these questions based on multidisciplinary expertise The team has a history of collaboration and funding and includes experts in biomaterials/soft actuators (Ware) and clinical management of incontinence (Zimmern). Published and preliminary data, supported in part by an R21 on a different type of dynamic sling, demonstrate the feasibility of creating magnetically responsive midurethral slings. Three specific aims are proposed: 1) Fabricate and characterize magnetic elastomer slings with controlled mechanical properties, geometry, and shape change when placed around a simulated urethra and in simulated scar. 2) Characterize the chronic stability of the magnetoelastic slings and elucidate the effects of reversible shape change of chronically implanted materials on the foreign body response. 3) Characterize the ability of the magnetoelastic slings to dynamically alter leak-point pressure in a guinea pig model.
