To provide a surgical system in which a pressure within a irrigation fluid container is controlled without need for direct ventilation to a gas contained in the fluid container.

The surgical system having a cassette equipped with an aspirant collection chamber and an aspiration exhaust line that drains into the aspirant collection chamber is provided. A fluid from the irrigation fluid container is vented into the aspirant collection chamber by a fluid line containing a valve. A source of pressurized air is connected to the fluid container, and is used to pressurize the fluid container. When the pressure within the fluid container needs to be increased, pressurized air from the pressurized air source is allowed to enter the fluid container. When the pressure within the fluid container needs to be decreased, the irrigation fluid is allowed to be bled out of the fluid container and enter the collection chamber. In this manner, a direct fluidic connection with the gas contained in the fluid container does not need to be maintained.