An improved method and device are provided for safe and efficient low power density endoluminal treatment of venous insufficiency. One such device emits pulsed or continuous energy radially through an optical fiber end with a conical shaped tip for 360° radial emission. In some embodiments, a conical reflective surface is distally spaced opposite to and faces the emitting tip for enhancing radial emission efficiency by reflecting out any designed or remnant forwardly transmitted energy in radial directions. Other devices include flat emitting faces sealed within protective, radiation transparent covers. Laser radiation is transmitted at a wavelength and power such that is it substantially entirely absorbed within the blood vessel wall to sufficiently damage the intravascular endothelium and, in turn, achieve blood vessel closure. Because the energy is substantially entirely absorbed within the blood vessel wall, the need for a local anesthetic along the treatment area of the blood vessel may be substantially avoided.