| 摘要 |
An endoscopic portal for establishing communication with a body cavity for the introduction of instruments therethrough includes a sleeve for providing a passage through a cavity wall and a valve biased to a normal closed position preventing the passage of instruments and fluids through the sleeve. The sleeve includes a distal end for being disposed in a body cavity, a proximal end for being disposed externally of the body cavity and a lumen between the distal and proximal ends. The valve includes a cylindrical valve body extending in a transverse direction across the lumen and having a plurality of diametric valve passages therethrough of different cross sectional sizes. The valve body is biased to the normal closed position wherein the valve body blocks communication through the lumen and wherein the valve passages are not disposed within the lumen. The valve body is movable axially from the normal closed position to position the valve passages within the lumen, and the valve body is rotatable about an axis transverse to the longitudinal axis of the sleeve to align a selected one of the valve passages axially with the lumen such that an instrument having a cross sectional size corresponding to the cross sectional size of the selected valve passage can be introduced through the lumen to extend through the valve body in sealing relation.
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