Viking Systems Inc (VKNG)

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Advantages of 3D visual effects in laparoscopic surgery

R Van Velthoven (Belgium)
Institut Jules Bordet,
Bruxelles, Belgium

Advances in laparoscopy have been made in parallel with the development of miniaturized endoscopic camera systems, which transmit images to a 2-dimensional screen. Developments thus far have been based on intra-abdominal procedures, which allow ample working space and laparoscopic views that enable the surgeon to perceive the relationships between different organs. These conditions exist for renal and adrenal procedures, and for most procedures involving the alimentary tract. In the pelvis, however, a relatively more constrained working space contains few organs. Although pelvic anatomy has considerable left-right symmetry, most of the surgical motions of a given procedure are axial rather than transverse due to the lateral confinement inherent to the pelvis. This can be particularly difficult for longitudinal dissection, for movements that are perpendicular to the main axis deep in the pelvis, or when the surgeon needs to frequently change instruments from one hand to the other (eg, urethral-vesical suture). In this context, enhanced depth perception is important.

The reproduction of 3-dimensional (3D) effects has been achieved by using polarizing glasses to view the monitor. Technically, this solution is not satisfactory, and it is tiring for the surgeon. Optimal reproduction of the 3D effect requires the simultaneous recording of 2 separate images (corresponding to left eye and right eye images) that are transmitted to 2 different monitors. The simultaneous viewing of the images corresponds as closely as is currently practical to the physiological conditions of human vision. The resulting visual comfort more closely approximates the high visual demands of a surgical procedure. Combined with anatomically correct head-hand triangulation (with the view preferably situated between the hands or immediately adjacent to this point), the effect provides a visual facility for the surgeon that is an incomparable improvement over the constraints inherent to monoscopic (2D) vision. Certain robotic systems provide these visual conditions. This is their major contribution, as compared to the other characteristics of robotic systems, whose contribution to the comfort of skilled laparoscopic surgeons is less important, in my opinion.

A more rudimentary system is composed of 2 small LCD screens attached to a lightweight headset, displaying the images at 10 to 15 cm from the surgeon's eyes. The relative loss of resolution on the LCD screens is compensated by the realistic 3D effect. The color resolution of this system can also be improved upon. Our experience has shown us that this system enhances surgical visual facility, notably during complex dissection (eg, in radical prostatectomy: incision preserving the neck of the bladder, preservation of the neurovascular bundles). This improvement translates into decreased operative time, decreased surgeon fatigue and increased safety for the patient (Shah and Darzi, 2001). The surgeon can get used to wearing the headset, which optimizes the stability and neutral position of the surgeon's head during operations. The relative sense of isolation from the operative field that results helps the surgeon concentrate on the maneuver being performed.

In conclusion, even though 3D effects currently provide an image reproduction less refined than that observed with 2D, single channel systems, 3D effect combined with instrument triangulation contributes decisively to the visual facility and quality of laparoscopic procedures. Although already used in robotics, but in a large workstation away from the operative field, 3D visual effects should benefit in the near future from technical refinements in visual resolution. These refinements, which include improved color vision, should generalize its use. Any system that helps improve the management of 3D objects manipulated in a 3D space can only contribute to improving the human factor involved in all surgical procedures, for the greater benefit of patients.

References
Shah J, Darzi A. Surgical skills assessment: an ongoing debate. BJU Int 2001;88:655-60