A duct is provided and includes a tubular member having an inlet portion, an outlet portion and a central portion interposed between the inlet and outlet portions and a tributary tubular member fluidly coupled to the tubular member at the central portion. The tributary tubular member includes first and second torus sectors defining first and second apertures, respectively, through which an upstream end of the central portion extends. The second torus sector is disposed within the first torus sector to define a sectioned toroidal annulus about the first and second apertures and between an exterior surface of the second torus sector and an interior surface of the first torus sector.