A support apparatus for supporting a trocar while the trocar extends through a body wall of a patient includes an inflatable collar and a slidable abutment collar commonly connected for engagement onto the trocar following which the slide collar is released to slide along the trocar. The inflatable collar is inflated to a set size by a manually operable pump on the slidable collar operated by squeezing finger abutments together up to a latch so that threaded portion expels the inflation fluid. The abutment member is shaped to be received on an outer surface of the trocar and adjustable longitudinally of the trocar sleeve so as to be located at a selected position by a manually movable latch collar. The inflatable collar and slidably collar are held connected by a manually operable release.