Laparscopy Video-assisted surgery represents more than a loss of three-dimensional vision Anthony G. Gallagher, Ph.D. a,b, *, E. Matt Ritter, M.D. a , Andrew B. Lederman, M.D. a , David A. McClusky III, M.D. a , C. Daniel Smith, M.D. a a Emory Endosurgery Unit, Department of Surgery, H-124, Emory University School of Medicine, 1364 Clifton Road, NE, Atlanta, GA 30322, USA b School of Psychology, Queens University, Belfast, Northern Ireland Manuscript received September 26, 2003; revised manuscript April 15, 2004 Abstract Background: Loss of depth cues is a major challenge facing surgeons performing video-assisted surgery (VAS). Whether the degradation of image quality from a video-displayed image plays a direct role in performance of VAS has not been studied. Methods: Twenty-four volunteer novice subjects were randomized to binocular direct-vision (BDV), monocular direct-vision (MDV), or video-imaging (VI) conditions. Each subject completed ten trials of a simple cutting task in a box trainer using standard laparoscopic instruments. Results: VI subjects made significantly fewer correct incisions than both of the other groups for all trials. Differences between the BDV and MDV groups did not reach statistical significance. Improvement in performance was more rapid in the BDV group than in either the MDV or VI groups. Conclusions: The degradation of image quality with VI has a detrimental influence on VAS performance above and beyond the loss of binocular vision. © 2005 Excerpta Medica Inc. All rights reserved. Keywords: Video-assisted surgery; Video imaging; Laparoscopy; Depth perception Minimally invasive surgery (MIS) is one of most significant developments in the field of surgery in recent history. MIS has gained widespread acceptance across many surgical disciplines with increasing numbers and kinds of cases being performed via this approach. Patients who undergo MIS frequently benefit from decreased pain, shortened hos- pital stay, and more rapid return to full activity [1]. How- ever, surgeons learning to perform MIS procedures are faced with a unique set of challenges. The adaptation to decreased tactile feedback and the need to retrain the per- ceptual and motor pathways of the surgeon’s brain to adapt to the “fulcrum effect” are both major hurdles that must be overcome [2,3]. The challenge most commonly associated with all forms of MIS is the use of a video image to view the operative field. Drawbacks associated with use of video imaging (VI) include loss of effective binocular vision and degraded image quality as a result of the differences be- tween currently available camera systems and the human eye. Although loss of binocular visual cues has been shown to lead to impaired performance in tasks which require visually-guided object grasping [4,5], some recent data sug- gest that binocular cues may not be as important as origi- nally thought [6,7]. In fact, although the visiomotor system may prefer binocular depth cues, monocular cues can pro- vide adequate information for the performance of most psychomotor tasks [4,7]. One group reported that, when binocular cues were isolated (ie, eliminating available mon- ocular cues) using a virtual reality– based grasping task, adequate information to correctly judge depth was not pro- vided [8]. Given these data, the difficulty of performing psychomotor tasks under VI conditions is not likely ex- plained simply by the loss of binocular vision; however, the effect of degraded image quality on psychomotor perfor- mance in a VI environment is unknown. Therefore, the aim of this study was to investigate whether loss of image quality would affect performance on a simple MIS task independent of the loss of binocular direct vision. It was hypothesized that MIS novices under * Corresponding author. Tel.: +1-404-727-1540; fax: +1-404-712- 2739. E-mail address: csmit27@emory.edu The American Journal of Surgery 189 (2005) 76 – 80 0002-9610/05/$ – see front matter © 2005 Excerpta Medica Inc. All rights reserved. doi:10.1016/j.amjsurg.2004.04.008