Medical instrument and system comprising such an instrument

A medical instrument comprising a free distal end intended to penetrate into a tissue or an organ and/or a blood vessel (V) and a proximal end connectable to a light source, said instrument comprising a tubular support in which is mounted at least one light guide, said support comprising a beveled distal end comprising at least one orifice forming a first optical outlet, for a substantially frontal emission of the light by said guide via said first optical output, said instrument further comprising at least one optical deflection means of the light forming a second optical output, for deflected light emission, comprising at least one machining on a distal portion of the instrument, with at least one reflective and/or concave polish configured for light convergence and one reflective and/or convex polish configured for a divergence of light, said polishing being carried out on said light guide and/or on said support.