An apparatus includes a light source configured to provide radiation at a wavelength and a conduit configured to direct radiation at a wavelength from the light source to a target location of a patient. The conduit includes a first optical waveguide extending along a waveguide axis, the first optical waveguide being a flexible waveguide having a hollow core, the first optical waveguide being configured to guide the radiation at through the core along the waveguide axis; and a second optical waveguide extending along the waveguide axis, the second optical waveguide having a hollow core and being coupled to the first optical waveguide to receive the radiation from the first optical waveguide and to deliver the radiation to the target location. The first optical waveguide is a photonic crystal fiber and the second optical waveguide is not a photonic crystal fiber waveguide.