Image rotation and reversal--major obstacles in learning intracorporeal suturing and knot-tying

A major stumbling block to teaching and learning the finer skills of laparoscopy is related to the "optical illusions" the video camera plays on the surgeon's eyes. Until now, the belief was that lack of coordination was the result of depth perception deficiencies resulting from the two dimensional plane of the video monitor. In reality, this is a minor problem that is easily surmounted with practice. A closer analysis of how organ orientation at the operative site compares to the video camera's fields of focus reveals the real problem: the major optical difference between laparotomy and laparoscopy involves rotation of the images received by the brain.

There are four major operating positions in laparoscopy: camera position, right camera position, left camera position and opposite camera position. The object in front of the camera has two components; the first, a reality image, which results from light reflected off the object as it exists in time and space. The second, a visual image, which represents the actual light entering our eyes. At right camera position the visual image is a 90 degrees counter-clockwise rotation of the reality image. At the left camera position the visual image is a 90 degrees clockwise rotation of the reality image. At opposite camera position, a 180 degrees rotation and complete reversal of the reality image occurs. It is only at camera position that the visual image is equal to the reality image, and we approach a scenario similar to that found in laparotomy. Every other position will be unlike what we were accustomed to in open surgery.