Supplementary Material for: The ChorioAnchor: Design and testing of a novel chorioamniotic anchoring device to enable percutaneous fetoscopic surgery

Introduction: Percutaneous fetoscopic surgery is hampered by an increased risk of preterm prelabor rupture of membranes (PPROM). Recent surgical techniques have shown that suturing the chorioamniotic membranes following laparotomy and uterine exteriorization is associated with a lower risk of PPROM compared to percutaneous in-utero surgery. This study presents the ChorioAnchor, a novel resorbable device that percutaneously anchors the chorioamniotic membranes to the uterine wall. Methods: Human factors testing and peel tests were used to simulate the worst-case in-use loading conditions, establishing the device strength requirements. Tensile testing was used to measure the time-zero strength of the device. Porcine cadaver testing was used to examine ultrasound visibility and acute handling characteristics. Short-term host response was examined through an acute 7-day implantation study in a rabbit model. Results: With a time-zero tensile strength of 47N, the ChorioAnchor exceeded the established 4N strength requirement. Both the ChorioAnchor and delivery device were seen to be clearly visible under ultrasound imaging. Short-term host response to the device was well within the range expected for this type of device. Conclusion: The ChorioAnchor meets its engineering requirements in the early stages of implantation. Future studies will examine the kinetics of degradation of the device in-vitro and in-vivo.