| 摘要 |
An endoscopic portal for establishing communication with a body cavity for the introduction of instruments through the endoscopic portal includes a first seal having a variable size passage to permit instruments of varying sizes to passed therethrough, a second seal disposed distally of the first seal and having a variable size passage axially aligned with the variable size passage of the first seal, and a first tubular expander aligned with the variable size passages. The first and second seals are biased to contracted or closed positions where their variable size passages have a first cross-sectional size and are movable to expanded or open positions where the variable size passages have a second cross-sectional size larger than the first cross-sectional size. The tubular expander can be disposed between the first and second seals so that opposite axial ends of the tubular expander are insertable in the seals to move the seals from the closed position to the open position such that instruments of various sizes can be introduced through the tubular expander and the seals. Alternatively, a separate tubular expander can be provided for each seal and made to move relative to that seal in order to cause the seal to move from the closed position to the open position. |
