Roux-en-Y Gastric Bypass Surgery Forum (RNY)

Obesity is a growing public health problem in the United States with nearly one-third of the US population meeting the definition of obesity, defined as having a body mass index (BMI) greater than 30 kg/m² [1].  To date, only bariatric surgery has been demonstrated to be of long-term therapeutic benefit for patients who are morbidly obese [2-5]. This dependence on surgical treatment has resulted in an impressive increase in the number of gastric bypasses performed in the United States increasing from 16,000 to 103,000 per year over the last 11 years [6]. The surgery itself is technically and physically demanding on the surgeon. A significant learning curve of 70-100 cases for the Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) [7-10] has been demonstrated, and complication rates and operative times tend to be highest in a surgeon?s first 75 cases [11].  Many of the challenges seen with this operation are secondary to the limitations of laparoscopy ? 2-D camera, long instruments, counterintuitive instrument movement, loss of two degrees of freedom and the abdominal wall torque caused by the morbidly obese abdominal wall. The strain on the surgeon can lead to fatigue, tremors and neuropathies.

Because of the technical challenges of the operation and the significant learning curve,  the authors developed the first totally robotic Laparoscopic Roux-en-Y Gastric Bypass (TRLRYGB) using the da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA). We felt that the daVinci system would offset the limitations of laparoscopy. The system provided 3-D camera, intuitive instrument movement, added two degrees of freedom, and placed the surgeon in an ergonomic position. We reported on our first early experience, demonstrating the feasibility, efficacy and safety of the procedure [12,13]. Our early results suggested that using the da Vinci system would improve both the learning curve and the ergonomics of the surgery [12, 13].

We perform a totally robotic variant of the Laparoscopic Roux-en-Y Gastric Bypass with a hand-sewn gastro-jejunal anastomosis as described by Higa et al [14].  Details of the surgical procedure including port placements and robot arm setup are described in detail elsewhere [12]. We made several changes to the technique described in [12] during the later cases of the series:  the right robot arm port was moved laterally (to the midclavicular line), a double-fenestrated grasper is now used for both bowel and stomach manipulation, we have shortened the length of sutures to 6-7 inches, and we now use Vicryl for the inner layer of the gastrojejunostomy instead of Ethibond (Ethicon Endosurgery, Cincinnati, OH).  In a review of our first 75 cases (15), the mean operative time for the 75 cases was 142 minutes with a range of 80-312 minutes. Removing from the analysis the six cases where a general surgery resident, rather than a minimally invasive fellow was the primary console surgeon, the mean operative time for the remaining 69 cases was 137 minutes with a range of 80-312min. Mean excess body weight loss was 83% at 3 months postoperatively.

There were four intraoperative complications, defined as events which required a portion of the primary operation to be re-done including:  a leak from the gastric pouch staple line detected during testing of the anastomosis which required oversewing, a stapler misfire requiring restapling to close the resulting gastrotomy, revision of the anterior layers of the gastrojejunostomy because we could not demonstrate that the anastomosis was patent during testing of the anastomosis, and perforation at the gastroesophageal junction by an orogastric tube which required oversewing. Major complications included a postoperative troponin leak, two late anastomotic strictures at the gastrojejunostomy which required dilation, and three patients who required re-operation. The cases requiring reoperation included a negative exploratory laparotomy for postoperative fever and tachycardia to rule out an anastomotic leak (the patient was later determined to have c. difficile colitis), a small bowel perforation proximal to the jejunojejunostomy detected one week postoperatively, and the development of an internal hernia at the jejunojejunostomy 9 months postoperatively which was repaired laparoscopically (the original mesenteric defect had been closed with Ethibond). The two strictures which developed were associated with the use of Ethibond  non-absorbable suture for the inner layer of the gastrojejunostomy, and after the second stricture, a change was made to Vicryl for the inner layer with Ethibond for the outer layer with no subsequent strictures. There were no post-operative anastomotic leaks. Minor complications were successfully managed medically and included asthma exacerbations, mild arrhythmias, mild incisional infections, post-operative bleeding and post-operative nausea and vomiting.

In addition to the 75 robotically completed cases, four cases were started robotically and converted. Two conversions were to open procedures, and in each case the patient?s liver was too large to be retracted laparoscopically without injury.  One case was converted to a laparoscopic procedure because the operative ports had been placed in abdominal wall folds, making docking of the robot difficult. Another case was converted to a laparoscopic procedure after the robot was inadvertently contaminated during an intraoperative search for a needle which had jammed in the trocar during withdrawal. The decision was made to continue the case laparoscopically rather than to wait for re-sterilization of the tools.

The one year weight loss of 83% of EBW is consistent with that report in the literature for purely laparoscopic roux en y gastric bypass  [16, 17]. The complication rates even for these early cases are below the reported averages of 2% leak rates and 4.3% rates of stricture for large established programs with over 100 cases [17].  These lower rates are consistent with the findings of other authors that demonstrated lower stricture and leak rates for gastrojejunal anastomoses sewn with the daVinci vs. laparoscopically [18].  We concur with other authors [19] that this is likely due to the ergonomic improvement that comes from the lack of abdominal wall torque, and the significant advantage in visualization and precision when sewing the G-J that the 3-D visualization affords.

We have found that the procedure continues to be faster than Laparoscopic Roux-en-Y Gastric Bypass, and that the individual surgeon learning curves continue to shorten as progression is made.  Leaks are one of the major sources of morbidity and mortality associated with the procedure [20], and tend to occur at greater rates earlier in training [8, 10]. Therefore, we feel that a procedure which shortens the individual surgeon learning curve, and has a lower early complication rate, would be of great advantage to patients of hospitals developing a new bariatrics program.   This is especially true as open surgical skills have been found to transfer more readily to robotic surgery than to laparoscopic surgery [21].

There are limitations to robot movement and optimal placement of the robotic ports is essential for successful robotic use [22]. For example, we found that placing ports in an abdominal wall port severely limited our use of the robot.  Our institution?s experience is that the procedure itself has a learning curve as does the institution. The institutional learning curve seems to play a crucial role in the success of a program.   Historically, considerable variation in operative times may be found among early adopters of any new surgical technology. Introduction of the da Vinci robot to a hospital is no exception, with some institutions, such as ours, reporting initially comparable OR times for the robot vs. laparoscopic procedures and faster learning curves with the robot [23], while others report significant increases in surgical times [24]. As individual operative tasks have been shown to be performed more quickly and accurately with the robot [25, 26], a surgeon using the da Vinci has the potential to achieve comparable or faster operative times when compared with laparoscopy. The major causes of increased OR times for robotic procedures seems to be room prep in between procedures, and robot setup time [27].  In addition, significant delays are also attributed to port placement and robot docking time with robot adjustment taking up to 27% of total operative time [28].  It is frustration with these perioperative delays and inefficiencies which is most often cited by surgeons as the chief reason why a da Vinci robot purchased for a hospital ends up not being used very much.  Our experience serves to emphasize the role of a dedicated OR team to the success of a robotics program.  It has also been shown that when OR teams undergo procedure specific training on the da Vinci prior to the OR, they may expect a 40% reduction in operative time and 50% reduction in set up time in procedure times. [29]  In our institution?s experience, simple things like familiarity of the scrub techs with the tools, sterilization staff learning the proper handling of tools, and the hospital fine-tuning appropriate stocking and re-ordering thresholds make the OR time flow much more smoothly.

Cost of the TOTALLY ROBOTIC LAPAROSCOPIC ROUX-EN-Y GASTRIC BYPASS vs. conventional Laparoscopic Roux-en-Y Gastric Bypass has not been addressed specifically in  our studies.  However, cost analysis of the da Vinci in minimally invasive cardiac surgery at a similar tertiary care center has shown that differences in cost between standard laparoscopic and robotic procedures are largely driven by OR time rather than differentials in instrument costs [30].  In the author?s experience, within 20 cases, our robotic OR times are consistently below that of our laparoscopic times, so that we would expect similar costs for the TOTALLY ROBOTIC LAPAROSCOPIC ROUX-EN-Y GASTRIC BYPASS and the Laparoscopic Roux-en-Y Gastric Bypass.

In conclusion, we have found that a totally robotic Laparoscopic Roux-en-Y Gastric Bypass is safe and feasible. It appears to shorten the learning curve for a complex and technically demanding operation. An experienced OR team and careful positioning of the robot are both crucial for successful adoption of this new technology.

Myriam J. Curet, MD, FACS, is Professor of Surgery and Senior Associate Dean for Graduate and Continuing Medical Education at Stanford University School of Medicine.

Catherine J. Mohr, MD, MSE, is Clinical Instructor at Stanford University.

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