A system for performing an endoscopic surgical procedure in a surgical cavity of a patient that includes a gas delivery device configured to deliver a flow of pressurized gas to a gas delivery lumen extending therefrom, a gaseous sealing module communicating with a distal end of the gas delivery lumen and configured to generate a gaseous seal within a gas sealed lumen extending therefrom, and an access port communicating with a distal end of the gas sealed lumen so as to provide sealed instrument access to the surgical cavity and maintain a stable pressure within the surgical cavity.