Bariatric surgery has become an effective treatment option for obesity and laparoscopic surgery has been the gold standard approach for several years. Recently, robotic surgery has emerged as a potential alternative to laparoscopic surgery. Overall, when adjusted for comorbid conditions and preoperative variables, the robotic approach is statistically similar to the laparoscopic approach in regards to major 30-day postoperative outcomes. This is consistently observed across all three procedures (sleeve gastrectomy, gastric bypass, and duodenal switch). However, statistically significant differences were noted with respect to the length of the operation and reoperations, especially in RYGB. Our results are unique in comparing all three major bariatric surgeries in a single large database study. Incorporating the most recent years of available MBSAQIP data many of our study findings, such as operative length and readmissions, showed similar rates to previously reported MBSAQIP studies. However, unplanned return to the operating room has been a point of controversy [3,4,5, 7,8,9,10].

Our results showed a statistically significant higher rate of unplanned reoperations within 30 days in robotic RYGB as well as a higher rate of postoperative wound disruption in robotic SG. These postoperative outcomes are consistent with prior literature [11]. Robotic surgery has shown similar trends in foregut surgery especially for hiatal hernia repairs in recent readmission database studies [12, 13]. Our data suggest that preoperative comorbid conditions such as COPD, prior foregut surgery, preoperative anticoagulation, and preoperative renal insufficiency, as well as characteristics including age, might be contributing slightly to higher reoperation rates in RYGB and higher readmission rates across all the robotic surgeries.

Postoperative bleeding and anastomotic-related complications, especially leaks, are considered the most common reasons for unplanned reoperations and morbidity. Our current dataset, which has leaks available from 2020, showed no significant difference between the laparoscopic and robotic approaches in either the DS or RYGB procedures. This is in part related to the lower total number of robotic DS and RYGB cases over 2 years (n = 1648 for DS and n = 22,866 for RYGB). Our results contrast with the retrospective study by Buchs N.C. et al. which showed that their robotic-assisted surgery group had a lower incidence of anastomotic leak (1.5% vs. 3.2%) and a shorter hospital stay (1.6 vs. 2.2 days) compared to the laparoscopic group [12, 13]. Our results showed similar leak rates between the procedures across platforms. Interestingly, SG (2020–2021 total n = 241,955) has a statistically significant higher rate (0.2% vs 0.1%) of leaks observed with the robotic approach. It is worth noting that, to our knowledge, this study includes the largest sample comparing leaks across the most common bariatric surgeries between approaches and is one of the initial reports comparing the leak rate for laparoscopic and robotic approaches across all major bariatric procedures in a large population database. As experience with RS has increased, the complications, especially leaks, have continued to show similar rates and trends when compared to the laparoscopic group.

The robotic approach has been proposed to be advantageous in patients with a high BMI classification as well as in technically difficult procedures like pancreatic surgery. In bariatric surgery, the DS is considered to be a technically challenging surgery, and robotic technology was adopted by some centers to show moderate benefits [14]. Our data showed that patients undergoing the robotic-assisted DS demonstrated a significantly higher rate of preoperative venous thrombosis requiring therapy, higher rates of prior foregut surgeries, and significantly higher BMIs. The higher BMIs in the DS group compared to the SG and RYGB could be explained by preference among bariatric surgeons whereas the choice to use the robotic-assisted approach in patients with higher BMIs could be explained by the better maneuverability offered by the robotic approach in cases with decreased intra-peritoneal space [11]. Our data suggest that utilizing a robotic approach for the DS is at least not statistically different from the laparoscopic approach with similar rates of leaks and unplanned reoperations. This trend is seen despite a patient population with a slightly higher severity of obesity, an increased need for anticoagulant therapy, and an increased rate of prior foregut procedures when compared to the laparoscopic patient population.

Our study does coincide with the current literature suggesting that robotic bariatric procedures have a longer average operation length [4, 7,8,9, 14]. In our data, RS had significantly longer operative times for all three procedures. The largest median difference was seen in the robotic duodenal switch which on average took 75 more minutes than the laparoscopic approach. This difference was smaller within the RYGB (robotic approach took 34 min longer on average) and sleeve gastrectomy (robotic approach took 23 min longer on average). Robotic-assisted RYGB did not show any decrease in median operative lengths across our data period. However, the median operative lengths for robotic-assisted SG and DS continued to decrease significantly per year during our data collection. This finding could be indicative of a learning curve associated with the robotic-assisted bariatric surgical techniques. Over time, the robotic approach should continue to improve and bring operative lengths closer to those with the laparoscopic approach, which should also bring down the cost associated with robotic surgery. In a recent publication by Ayesha P. Ng et al. utilizing the National Inpatient Sample (NIS) database, the robotic approach is associated with higher overall cost compared to the laparoscopic approach in select abdominal procedures (elective gastrectomy, cholecystectomy, colectomy, ventral hernia repairs, hysterectomy, and abdominoperineal resection) [15]. Interestingly, this cost discrepancy widened throughout their data period, though they remark that the average age and comorbidity burden increased across the period in the robotic group as well which is consistent with our study results. The increasing cost is an interesting finding that seems to contrast with our findings of decreasing operative lengths per year. A possible explanation is that robotic technology has seen continuous improvement since its implementation and it could be that the newer platforms, while allowing for more efficient operations length-wise, have a higher initial investment that has led to increasing cost of use. The per-year decrease in median operative times for the robotic-assisted SG and DS suggests that the argument of cost should be made longitudinally rather than be compared to one snapshot analysis of procedure-related costs which has been the norm currently.

It is also important to highlight the technical differences between the robotic and laparoscopic anastomotic procedures. The anastomotic technique in RS more commonly involves suturing compared to a stapled anastomotic technique in the laparoscopic approach. Our data does not include details about intraoperative technique, but it has been debated as one of the important factors in long-term outcomes including weight loss, stricture, and anastomosis-related complications. Literature reports have shown significantly lower stricture rates with robotic surgery [10].

Our findings of higher unplanned reoperations in the robotic RYGB and a higher rate of wound disruption in the robotic SG beg the question of the clinical reasons behind these findings. Anastomotic leaks and bleeding are considered the most important reasons for reoperation; however, in our data, neither of these was significantly different between approaches, making it harder to elucidate the reasons behind these findings. Some patient factors such as COPD were higher in the robotic SG group, and this may have contributed to a higher rate of wound disruption, an association suggested in prior literature [16]. However, the absolute differences between our significant findings are small, and the most important clinical takeaway from this data is that there is no clear inferiority between the robotic and laparoscopic approaches in bariatric surgery with regard to patient safety.

Our retrospective analysis does have limitations, one being the lack of long-term follow-up data (limited to 30 days). Another limitation is the lack of data concerning the surgeon and the operating room team. Much of the current discourse regarding the efficacy of laparoscopic vs. robotic surgery concerns the lag between technological advancement and gaining procedural experience. As there is no way to discern how experienced a surgeon or institution is in the MBSAQIP data, we are unable to comment on how surgical experience may have influenced our results. To elucidate if these extended operative times when compared to the laparoscopic approach are inherent to the robotic platform or a short-term finding that will resolve as procedural experience with this new technology improves, a comparative study should be conducted evaluating postoperative bariatric surgical outcomes and operative times in the robotic-assisted approach adjusting for surgeon experience. This limitation also impacts the external validity of our study, as it is a fair assumption to say that a surgeon and operating team that primarily performs one type of bariatric procedure will be more efficient and efficacious than a surgeon who performs a wider variety of procedures with less individual frequency. Our analysis and discussion are comparing all three bariatric procedures to assess for any apparent inferiority; however, if a surgeon is significantly more comfortable and experienced with one procedure and platform over others, then it is unlikely that our generalized results will apply to their specific circumstance. There also was not enough volume of data for the DS to allow for an adjusted analysis of postoperative wound disruption or mortality. As the MBSAQIP database continues to add years of data, the outcomes of DS can be better assessed.

One more limitation that is found in our study as well as a large portion of bariatric surgery literature is the retrospective design. The highest quality study for the assessment of causal relationships would be a randomized controlled trial utilizing a large patient population. This is of course difficult in bariatric surgery as ultimately it is patient preference that dictates the type of procedure performed (SG, DS, RYGB) after a discussion with their surgeon. However, randomization for the usage of the robotic or laparoscopic platform, independent of what bariatric procedure is decided upon, is much more feasible. With a large sample size and a longer follow-up period, this would provide invaluable data in the discussion of laparoscopic vs. robotic surgery outcomes. This could also remove the limitation arising from the lack of knowledge of surgeon expertise; as this would be a prospective study with known participants, these metrics could be easily accounted for. It may even reveal how significant differences in outcomes are between surgeons of different experiences.