Endoscopic expandable retraction device

Apparatus for retracting an organ inside the body to gain access to an adjacent tissue, the apparatus comprising:

• expansible cage means capable of being inserted into the body through a small incision or puncture in a collapsed state, the expansible cage means including a bistable spring structure, the bistable spring structure having a first stable state wherein the bistable spring structure has a closed structure capable of being inserted into the body through a small incision or puncture, and a second stable state wherein the bistable spring structure has an open, cage-like structure, and
• expansion means for selectively expanding the bistable spring structure inside the body from the first stable state to the second stable state, the expansion means including an envelope enclosing a fluid-inflatable chamber, the bistable spring structure being attached to the envelope inside the fluid-inflatable chamber, and wherein:
• the expansible cage means is additionally capable of maintaining the expanded state independently of the expansion means after the expansible cage means has been expanded by the expansion means to the expanded state.