A device for creating an operative space within a body lumen for the performance of a medical procedure, including a pressurizable, expandable balloon element insertable into the body lumen. The balloon element includes an interior space for receiving an inflation fluid. The device further includes an ingress valve coupled with the balloon element and insertable therewith into the body lumen. The ingress valve is capable of being opened to allow the interior space to be filled with the inflation fluid and closed to retain the inflation fluid in the interior space. The device may also include an egress valve coupled with the balloon element and insertable therewith into the body lumen. The egress valve is closed when the interior space is filled with the inflation fluid and is capable of being opened to allow the inflation fluid to vent from the interior space.