Trocar seal assemblies are disclosed which consist of a helically-shaped seal positioned within a trocars cannula wherein, as an instrument is inserted through the central bore of the helically-shaped seal, the helically-shaped seal expands, thereby increasing the diameter of the central bore. In other embodiments, a protective member is positioned within a retaining member wherein the protective member is configured as a helix and, as an instrument is inserted through the central bore of the helix, the helix expands, thereby increasing the diameter of the central bore.
