Patent ID: 8034072

Claim:
A surgical access assembly comprising: a percutaneous access sheath comprising a proximal portion and a distal portion, wherein the distal portion is expandable from a first, smaller cross sectional area to a second, larger cross sectional area, and wherein the second, larger cross sectional area is sufficiently large to provide a passageway for passing surgical instruments to a surgical treatment site, wherein the proximal portion comprises an inner layer and an outer layer coaxially surrounding the inner layer, and wherein the distal portion comprises only the inner layer and has a length between 4 cm and 12 cm, the inner layer defining an internal lumen extending through both the proximal portion and the distal portion of the percutaneous access sheath; an insertion sheath comprising a proximal section and a restraint section, the restraint section surrounding at least part of the distal portion of the percutaneous access sheath to restrain the distal portion of the percutaneous access sheath in the first, smaller cross sectional area, the restraint section of the insertion sheath being releaseable to allow expansion of the distal portion to the second, larger cross sectional area, the proximal section comprising an opening in a sidewall for receiving the percutaneous access sheath, wherein the insertion sheath tapers between the proximal section and the restraint section such that an internal passage extending axially along the length of the insertion sheath has a smaller cross sectional profile in the restraint section than in the proximal section; a deployment device positionable inside the distal portion of the percutaneous access sheath, the deployment device comprising an inflatable member and a guide wire lumen, the inflatable member being inflatable to expand the distal portion from the first, smaller cross sectional area to the second, larger cross sectional area; and a guide wire, wherein the surgical access assembly is moveable along the guide wire to be directed to the surgical treatment site.