While cladding layers are essential for optical confinement in conventional waveguides, they limit spatial efficiency and integration density intrinsically. Recently, a cladding-free waveguide framework was proposed, in which each layer simultaneously serves as a signal-guiding core and an effective cladding for adjacent layers. However, existing photonic-crystal-based implementations involve complex three-dimensional architectures and additional metallic encapsulation, limiting further optimizations and on-chip integration. Here, we demonstrate a cladding-free plasmonic waveguide platform based on metasurface heterostructures with separated hyperbolic and elliptic equifrequency contours (EFCs). This approach harnesses the intrinsic subwavelength confinement of surface waves while maximizing spatial utilization. Crucially, the heterostructure interface supports an additional topologically protected edge state, characterized by high localization and singular field enhancement. Microwave experiments verify simultaneous, multiple-channel signal transmission and stable operation across a 90° bend. Our work significantly enhances the transmission channels of plasmonic waveguides, opening new avenues for on-chip photonic integration.