Density-dependent occlusion performance of a hydrosalpinx occluder: Hydrodynamic and in vivo evaluation

Hydrosalpinx significantly reduces the success rate of in vitro fertilization-embryo transfer; however, the absence of dedicated tubal occlusion devices in current clinical practice limits the standardization of its treatment. Here, we designed and fabricated a dual-disc shape-memory alloy occluder for interventional embolization of hydrosalpinx, with structural density defined as the circumferential wire coverage fraction (48-96 NiTi wires across three configurations). The effects of structural density on occlusion performance and inflammatory response were systematically investigated through in vitro hydrodynamic testing and in vivo animal experiments. The results demonstrated that occlusion efficacy increased with structural density. Compared with a single occluder, double occluders exhibited more stable flow attenuation performance and reduced the equivalent permeability by 39.3 %. Histological evaluation indicated that all device configurations induced mild inflammatory responses; however, no observable aggravation of inflammation was associated with increasing structural density. Collectively, this study presents a shape-memory alloy-based occlusion strategy for hydrosalpinx and provides quantitative biomechanical evidence linking structural architecture to flow-resistance behavior, offering a potential engineering basis for device optimization and future translational development.