Patent ID: 7485092

Claim:
A tissue dissector, comprising: an elongated tubular body having a central axis extending between a proximal end and a distal end and enclosing an endoscopic imaging element; and a dissecting, viewing and dilating unit removably mounted on the distal end of the tubular body, including: a transparent distal tip having substantially conical tapered outer walls converging distally with conical symmetry about the central axis from a cylindrical diameter to a blunt end for dissecting tissue, the tip being disposed on a distal end of the body to dissect tissue and facilitate passage of the tubular body through tissue under visualization through the tip by the endoscopic imaging element; and a non-inflatable dilating element spaced proximally a selected length away from the cylindrical diameter of the distal tip and having an exterior contour that is disposed with rotational symmetry about the central axis and that gradually increases in cross-sectional dimension symmetrically about the central axis in the proximal direction from a distal edge of the dilating element that is spaced the selected length from the cylindrical diameter of the distal tip to a maximum cross-sectional dimension greater than the cross-sectional dimension of said distal edge, the dilating element then decreasing in cross-sectional dimension symmetrically about the central axis in the proximal direction to a cylindrical diameter smaller than said maximum cross-sectional dimension at a proximal edge for facilitating atraumatic expansion of tissue following dissection by the tapered distal tip during advance of the tissue dissector through tissue, said selected length of spacing having an outer-dimension less than the maximum cross-sectional dimension of the dilating element and positioning the dilating element within an angle of the symmetrically conical tapered outer walls of the tip to inhibit the dilating element from impeding contact of the outer walls of the tip with a target vessel.