Abstract: An auxiliary apparatus for surgical operations, comprising a structure which supports a processing unit programmed to manage a virtual three-dimensional model of an organ to be operated on. A monitor visualizes the virtual three-dimensional model. A contactless sensor detects the movements of a hand and is connected functionally to the processing unit in order to virtually manipulate the virtual three-dimensional model as a function of the movements of the hand. The processing unit displays on the monitor an image that represents the hand, is adapted to follow the movements of the hand in the detection field of the sensor, and is variable at least as a function of specific movements of the hand that correspond to respective manipulation commands and/or operating commands.