A self-supporting retractor for holding open an anatomic space for performing endoscopic surgical procedures. The retractor includes a substantially rigid elongate member, having proximal and distal ends, and having an arch shape or "C" cross-section, defining a passage and longitudinal working window...http://www.google.es/patents/US5913818?utm_source=gb-gplus-sharePatente US5913818 - Vascular retractor
