Performing laparoscopic surgery is significantly more stressful for the surgeon than open surgery

Background: The awkward visual and physical interface of video-endoscopic s urgery (VES) has been shown to increase the physical workload of the surgeo n, yet there is a lack of objective information on the mental effort and st ress demanded by VES techniques. This study addresses the hypothesis that V ES is more stressful than open surgery using an ergonomic analysis of surgi cal tasks in a laboratory setting. Methods: A portable ergonomic work station was developed using a software V irtual Instrument (VI) interfaced with electronic hardware to compare the m ental workload of 28 surgeons. The task was knot tying. The independent var iable was work condition: rest, open technique, or VES technique. Dependent variables were tonic skin conductance level (SCL), electrooculogram (EOG), and subjective reports of concentration (CON) and stress (STR). Statistica l analysis used nonparametric methods. Results: Subjects tied fewer knots using the VES technique (p < 0.05). The SCL increased progressively from rest to the open task to the VES task (p < 0.05), correlating with the subjects' reported increase in mental stress l evel (p < 0.05). Eye blinks decreased from rest to the open task (p < 0.05) , consistent with the subjects' reported increase in level of mental concen tration. From the open to the VES task, eye blinks increased (p < 0.05), as would be expected given the greater demands of the VES task. Experienced s ubjects demonstrated less variability in SCL levels across tasks. Conclusions: VES technique requires greater concentration and places greate r mental stress on surgeons than to open surgery. More experience with VES may decrease this effect. Studies are needed to improve the human-technolog y interface the stress.