EP10.12: Insertion and adhesion of a sealing system with a cyanoacrylate‐based adhesive and a nitinol mesh for fetal membrane defects

To assess the feasibility of insertion and intermediate-term adhesion of sealing system (SS) patches composed of a nitinol-integrated silicone patch and a cyanoacrylate-based bioadhesive (CbB) - for fetoscopy-induced membrane defects. Ex vivo experiments using term human amniotic membranes on top of a cylinder containing a mixture of saline and amniotic fluid. The membrane was then affixed with a silicone phantom. With a pressure of 20mmHg set in the cylinder, a 14F trocar was inserted through the phantom into the cylinder to mimic a real fetoscopic trocar insertion. Three types of SS patches were compared: silicone with CbB (n = 10), silicone-nitinol-6-arm-thin with CbB (n = 10) and silicone-nitinol-6-arm-thick with CbB (n = 10). The patches were folded and preloaded in a custom-made 12F introducer, which was then inserted into the 14F trocar. The patch was released into the cylinder, and allowed to adhere to the membrane. We measured insertion time, successful insertion, and complete adhesion at 5, 15, 30 and 60 minutes. The median insertion times of all three SS groups were under 1 minute, with no significant difference among them (P = 0.899) and all insertions were successful. The 5-minute complete adhesion rates were no significantly different among them (P = 0.094). However, the nitinol-containing SS had higher complete adhesion rates at 15, 30 and 60 minutes than the plain silicone SS (50% for silicone with CbB for all three intervals, 90% for silicone-nitinol-6-arm-thin with CbB, and 100% for silicone-Nitinol-6-arm-thick with CbB, P = 0.027). Ex vivo fetoscopic insertion of bioadhesive silicone patches is feasible. Incorporating a nitinol mesh into a sealing system also improves adhesion, likely due to its superelasticity and shape memory, preventing patch deformation after fetoscopic insertion. Further studies are needed to evaluate the long-term adhesion and toxicity of CbB and nitinol.