Abstract: A medical device for forming an external extension of the pneumoperitoneum, thus allowing the surgeon more flexibility in a surgical procedure. The device includes an enclosure and an elastically deformable flange or ring at an open end of the enclosure. The flange/ring is deformed and inserted into a trocar puncture site, upon which it deploys against the inner surface of the abdominal wall. By maintaining a gentle lifting force on the external portion of the device (this being essentially a balloon shape) the neck of the device forms a seal between the opening in the abdominal wall and the `balloon`, allowing the insufflation gas to inflate the external `balloon` or `bubble` portion of the device. Once inflated, the internal pressure maintains the device in a stable shape. The device includes one or more valved openings which allow access to the interior of the balloon, and hence the abdominal cavity.