RYGBP is a technically and ergonomically challenging surgery to perform using the laparoscopic technique. While laparoscopic surgery frequently results in improved recovery time and reduced hospital length of stay for patients compared to open surgery, it often does so at the expense of the surgeon’s effort. Multiple studies have documented the ergonomic problems associated with laparoscopic surgery [5–7, 10, 12, 13, 17]. Laparoscopic surgery has been found to necessitate relatively high muscular loading compared to open surgery, and also requires the surgeon to assume atypical, awkward postures for extended periods of time [8, 13]. The upper extremities perform repetitive awkward movements while the neck and trunk are maintained in a more static posture, both leading to physical stress on the surgeon.  Questionnaire-based studies on laparoscopic surgeons have found increased rates of finger numbness and eye strain  as well as reports of frequent pain or numbness in the neck and upper extremities following laparoscopic operations .
The da Vinci telerobotic surgical system was developed in response to some of the major challenges associated with traditional laparoscopic techniques , . Technical limitations of laparoscopy, including the fulcrum effect caused by the body wall and the long length of laparoscopic instruments, are avoided by the master/slave design in which the surgeon sits at a remote console and controls up to three robotic arms with surgical instruments. Dexterity and agility are also improved while physiologic tremor and friction are reduced by electronically controlling the seven-degree-of-freedom instruments . Surgeons report that this feature results in improved tissue manipulation and specifically is better for fine tissue dissection and suturing then traditional laparoscopic instruments . The robot is further designed with a binocular endoscope and a stable camera platform, providing the surgeon with a steady three-dimensional view of the surgical field, in contrast to the unstable hand-held camera and flat two-dimensional field seen with traditional laparoscopy [18, 20].
The da Vinci robot was initially designed for cardiac surgery and has been used extensively by cardiac surgeons for procedures such as coronary artery bypass grafting and repair of mitral valves and atrial septal defects [20, 21]. Multiple abdominal surgeries can also be safely performed with the robot, including cholecystectomy, esophagectomy, fundoplication, Heller myotomy, gastrectomy, splenectomy, pancreatectomy, collectomy and RYGBP. Urologic and gynecologic surgeries have also been described [20, 22].
Though the da Vinci robot was designed with an ergonomically optimal operating position in mind, relatively few studies have investigated this topic. For example, robotic surgery may mitigate the excessive flexion and ulnar deviation at the wrist seen with the use of traditional laparoscopic instruments because the surgeon is able to control the movement of the instruments from a remote console while a seven-degree-of-freedom actuator moves the instruments. Thus the robotic system more closely mimics the movement of the human wrist and hand while physically assuming the awkward positions and forces that would otherwise be put directly on the surgeon. A recently published study comparing robotic and laparoscopic technique for completing a set of simulated surgical tasks in the laboratory setting reported significantly lower RULA and job strain index (JSI) scores for the robot, leading the authors to conclude that robotic surgery does not add additional mental stress to the surgeon and provides a more comfortable environment in which to work . The authors evaluated ergonomic results in medical students, junior internal medicine and junior surgery residents who had no laparoscopic experience in the laboratory with simulated surgical tasks. Our study evaluated a board-eligible surgeon who had completed his entire general surgical residency with advanced laparoscopic skills in a clinical setting during an actual operation. In this situation, we were assessing real-life ergonomic problems. Although this is clearly a pilot study, our results are consistent with the published literature, indicating that robotic RYGBP surgery is associated with less musculoskeletal discomfort in the upper back and more-ergonomic positioning of the upper arm, lower arm, wrist, and wrist twist.
The improvement in ergonomics and comfort of robotic surgery do not seem to have an adverse effect on performance compared to laparoscopic surgery . Our data demonstrated that operative times were significantly shorter for the robotic cases than for the laparoscopic cases. This is consistent with the first description of totally robotic RYGBP surgery, which reported comparable operating times with the laparoscopic technique, no change in the rate of minor and major complications and a very short learning curve . A study evaluating the learning curve for suturing and dexterity skills using either the da Vinci robot or standard laparoscopy showed that novice surgeons learn difficult tasks more quickly using the robot . Another prospective analysis of a variety of robot-assisted surgical procedures (211 in total) reported comparable results compared to traditional laparoscopic surgery in terms of mortality, complications and length of stay . A further study on aortic replacement in pigs found the robot-assisted technique to be superior to standard laparoscopic technique due to shorter operating time, fewer complications and less blood loss .
Other studies, however, report time loss with robot-assisted laparoscopic cholecystectomy compared to traditional techniques, with one study citing increased time required for set up and sterile draping  and another citing increased operation time due to slow, cautious movement of the robot arms by the surgeon and inappropriate instruments . Another study comparing laparoscopic skills performance between standard instruments and the da Vinci robotic system found no time advantage when performing fine tasks (intracorporeal knot tying and running stitches with 4-0, 6-0 and 7-0 sutures), though the robot was more precise. They further determined that basic task performance (running a 100-cm rope, placing beads onto pins, and dropping peanuts into cylinders) with standard instruments was actually faster and equally precise as with the robotic system. The authors thus conclude that robotic systems are not of benefit for general surgical procedures, but may be more useful in surgeries that require more fine suturing . A study comparing robotic with standard laparoscopic technique for performing a small-bowel anastomosis in a porcine experimental setup showed significantly shorter time required per stitch for the robot and more stitch errors for the standard group. These authors thus concluded that robotic assistance may be of greater benefit when performing more-complex manipulative maneuvers .
Haptic sensors have not yet been incorporated into the da Vinci robot, thus visual cues must be used to determine tactile and tensile forces. This lack of tactile feedback is reported as a deficit of the system, especially in determining tissue and suture tension [16, 20, 26, 28]. Another potential drawback to robotic surgery is the effect of the work station and the viewing angle on discomfort in the neck. The surgeon sits at a console and looks down into the visual field throughout the case. The higher neck BPD and trunk RULA scores seen at the end of the robotic cases may reflect an ergonomic disadvantage to the current workstation of the da Vinci system.