A collapsible medical device is used for occluding an opening used for fetoscopic surgery. The device includes tubular woven metal fabric composed of braided metal strands, said woven metal fabric having an expanded preset configuration comprising an hourglass-shaped element and a waist element at a midpoint, wherein each end of the hourglass-shaped element has a diameter of about 5 mm, wherein the waist element has a diameter that is less than a diameter of each end of the hourglass-shaped element, said woven metal fabric further includes a bulbous element coupled to one end of the hourglass-shaped element via a shaft, wherein the woven metal fabric is deformable to a lesser cross-sectional dimension for delivery through a channel in a patient's body to said opening, and the woven metal fabric having a memory property whereby the medical device tends to return to said expanded preset configuration when unconstrained.