An apparatus for retracting an organ inside the body to gain access to an adjacent tissue Includes an inflatable main chamber having a thin, flexible main envelope. Inflation of the main chamber within the body results in retraction of body tissues or organs to retracted conditions. During use an aperture may be formed in the main envelope to provide access through the main chamber to body tissue. An inflatable secondary chamber defines a cage positioned within or around the main chamber and maintains retraction of organs retracted by the main chamber notwithstanding formation of an aperture in the main envelope.