Background: Restricted depth perception in laparoscopy with two-dimensional imaging has been reported to be a major disadvantage of minimally invasive procedures. Three-dimensional imaging units have been available for almost 2 years and are slowly being integrated into endoscopic surgery. So far, potential advantages or disadvantages have not yet been studied prospectively.

Methods: We evaluated the effects of three-dimensional imaging on surgical performance and its influence on surgeons at different experience levels in a prospective randomized trial. Twenty participants without laparoscopic experience (novices), 20 with less than 50 laparoscopic procedures (beginners), and 20 with more than 50 laparoscopic procedures (advanced surgeons) took part in two different tests (tube test and loop test) on a pelvitrainer. In random order, each test was conducted using a three-dimensional imaging unit under two-dimensional and three-dimensional conditions. During each test, the time was measured and the mistakes counted. The difference of time and number of mistakes for two-dimensional and three-dimensional conditions were calculated for each participant.

Results: Speed ( p < 0.0001) and accuracy ( p < 0.0001) were significantly better under three-dimensional conditions irrespective of the randomized sequence of each individual test. Speed was also influenced by individual experience ( p > 0.02). Performance time decreased by 24.4% ± 2.8% (m ± SD), and the number of mistakes decreased by 52.5% ± 27.9% (m ± SD), as compared with the two-dimensional mode, with no significant influence of individual experience.

Conclusions: Three-dimensional imaging significantly improves performance (speed and accuracy) regardless of previous laparoscopic experience. Thus, three-dimensional imaging may further improve the safety aspect of minimally invasive surgery. (Gastrointest Endosc 1996;44:262-7.)