Laparoscopic cannula

摘要

A cannula is provided for laparoscopic surgery wherein the cannula comprises a housing and elongated tube with a passageway formed within the housing so that laparoscopic instruments may be passed through the housing and the elongated hollow tube into the abdominal cavity of a patient. A pair of rollers are mounted within the housing, the rollers being spring-urged together to close the passageway through the housing when an instrument is withdrawn. A slidable plate having apertures of different sizes are mounted in the housing with the apertures provided with slitted seals therein to close the passageway through the housing. The varying sized apertures in the slidable plate permit laparoscopic instruments of varying diameters to be used and to maintain an effective seal around the instrument. In another embodiment of the cannula a valve is provided which is closed when the rollers within the housing are in engagement with each other. When a laparoscopic instrument is passed through the housing to separate the rollers, the valve moves to an opened position to permit the laparoscopic instrument to pass therethrough.