A secure attachment method and structure for a wire (including non-metallic fiber, yarn, cable, etc.) is provided within a steerable catheter that includes a proximal end, a distal end, and an intermediate catheter body length therebetween, with at least a first catheter lumen extending longitudinally through the catheter body, at least a first elongate wire disposed longitudinally through the first catheter lumen, and a first adhesive having a first viscosity, the first adhesive disposed substantially within, and securing the wire to, the first longitudinal catheter lumen, where at least a lengthwise portion of the wire is frayed or otherwise at least partially disaggregated. The structure and method provides for robustly secure affixation that will allow steering/deflection control by manipulation of another portion of the wire.