An anchorable cannula adapted for positioning within an opening formed in
tissue includes a cannula body having a proximal portion and distal
portion. The proximal portion and the distal portion are linked by a
circumferential ring positioned therebetween. The proximal portion
includes a series of foldable arms extending upwardly from the
circumferential ring and ending at a circumferential seal ring formed at
a free end of the proximal portion. The distal portion includes a series
of foldable arms extending downwardly from the circumferential ring and
ending at a circumferential seal ring formed at a free end of the distal
portion.