NUMERICAL MODELLING OF A SYNTETIC MESH IMPLANT TO REPAIR THE UTEROSACRAL LIGAMENT Elisabete Silva (1), Jorge Bessa (2), Marco Parente (1,2), Teresa Mascarenhas (3), António Fernandes (1,2) 1. LAETA, INEGI, Portugal; 2. Faculty of Engineering, University of Porto, Portugal; 3. Dep. of Obstetrics and Gynecology, CHSJ-EPE / Faculty of Medicine, University of Porto, Portugal Introduction In 2019, a study showed that 41-50% of women over the age of 40 are affected by pelvic organ prolapse (POP), which is a common urogenital condition 1. Others studies showed that 11% of all women risk of undergoing POP surgery and the re-operation after Figure 2. Experimental curve of the synthetic mesh. surgery was about 30% 2,3. Until, recently, surgeons relied on the use of meshes in reconstructive surgeries, Results but on April 16, 2019, the FDA has forbidden its use for transvaginal repair of anterior compartment POP, since The maximum magnitude of displacement of the uterus its safety and effectiveness was not demonstrated in the for asymptomatic model was approximately 29 mm. The context of patient population in a clinical trial. However, rupture of the UL caused an increase of 28% in this clinical trials are very expensive and can last for several displacement. The insertion of the synthetic mesh years. Computer models and simulation can potentially implant caused a reduction of the displacement (23%), be used in clinical trials as an alternative source of prior when compared with asymptomatic model. information. The main aim of this study was to simulate an implant Table 1. Maximum magnitude of displacement of the mesh to mimic the uterosacral ligament function based uterus. on pelvic computational model. For this purpose, was Max. Mag. Disp. Variation developed a computational model of a synthetic mesh, Variable Uterus [mm] (%) to repair the POP, based on existing specifications on the market. Asymptomatic 29.01 … POP (w/o UL) 37.23 28 Methods Synthetic Mesh 22.44 23 Note: POP (w/o UL) - pelvic organ prolapse without uterosacral In this work was used a pelvic cavity computational ligament; Max. Mag. Disp Uterus - maximum magnitude of model, including the pubic bone, the pelvic organs, the displacement of the uterus. pelvic floor muscles (PFM), and other supporting structures (Fig. 1) 4. The mechanical behavior of the Conclusions mesh implant (Fig. 1b)) was modeled, assuming a The obtained results show that the computational model hyperelastic behavior, based on experimental curve that was able to discriminate the effect of synthetic mesh was obtained through uniaxial tensile tests performed in implant to repair uterine prolapse when UL failure our laboratory (Fig. 2)). occurs. The computational models can provide powerful Computational simulation of Valsalva maneuver was insights on the mechanisms underlying and predict the performed for progressive increase in intra-abdominal effects of the mesh implants in the pelvic tissues, in a pressure (IAP) up to 4 kPa. relatively inexpensive, personalized, fast and safe way, without resorting to random controlled trials and animal tests. References 1. Abhyankar P, et al. BMC Womens Health 2019; 1–12. 2. Segal S, et al. Curr Bladder Dysfunct Rep 2012; 7: 179–186. 3. Olsen A, et al. Obs Gynecol 1997; 89: 501–506. a) b) 4. Brandão S, et al. J Biomech 2015; 48: 217–223. Figure 1. Pelvic computational model (a) and synthetic mesh implant model (b). (1) rectum, (2) uterus, (3) Acknowledgements bladder, (4) pubic bone rectum, (5) arcus tendineous fasciae pelvis, (6) pelvic fascia, (7) PFM, (8) The authors acknowledge the funding of Project SPINMESH, uterosacral ligament (UL), (9) cardinal ligament. through Fundo Europeu de Desenvolvimento Regional (FEDER) - POCI-01-0145-FEDER-029232. 26th Congress of the European Society of Biomechanics, July 11-14, 2021, Milan, Italy .