| 主权项 |
1. A cannula assembly which comprises:
a cannula adapted for insertion within tissue, the cannula including a longitudinal passage extending along a longitudinal axis of the cannula for passage of a surgical instrument, and defining proximal and distal ends, the cannula including a shaft; and an expandable member mounted to the cannula and longitudinally spaced from the distal end, the expandable member adapted to expand, upon introduction of fluids therein, in a radial outward direction relative to the longitudinal axis whereby the expandable member engages the tissue to facilitate anchoring of the cannula relative to the tissue, and in a radial inward direction relative to the longitudinal axis and within the longitudinal passage to facilitate formation of a seal about a surgical instrument positioned within the longitudinal passage, wherein the cannula shaft extends through the expandable member; wherein a portion of the expandable member is disposed radially inward of a portion of the cannula longitudinally aligned therewith, and a portion of the expandable member is disposed radially outward of a portion of the cannula longitudinally aligned therewith. |
