THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY ORIGINAL Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. Published online 24 November 2014 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/rcs.1621
ARTICLE
A comparative retrospective study of robotic sleeve gastrectomy vs robotic gastric bypass
Radomir Kosanovic1 Rey Jesús Romero1 Charan Donkor1,2 Armando Sarasua1 Jorge Rafael Rabaza1,2 Anthony Michael Gonzalez1,2* 1
Department of General and Bariatric Surgery, South Miami Hospital, Baptist Health South Florida, Miami, FL, USA
2
Florida International University, Herbert Wertheim College of Medicine Florida, Miami, FL, USA *Correspondence to: A. M. Gonzalez, Florida International University, Herbert Wertheim College of Medicine Florida, 7800 SW 87 Avenue, Suite B-210, Miami, FL 33173, USA. E-mail: [email protected]
Abstract Background The introduction of the robotic platform to bariatric surgery has brought forth a novel approach, with modifications to the standard laparoscopic sleeve gastrectomy (LSG) and laparoscopic gastric bypass (LGB). The purpose of this study was to match robotic gastric bypass (RGB) vs robotic sleeve gastrectomy (RSG) and compare them to those observed with the laparoscopic platform. Methods A retrospective data collection of RSGs and RGBs from a single institution was performed. Groups were compared. Results This study included 134 RSG and 165 RGB patients. RGB has a longer surgical time (p < 0.001) and a higher incidence of long-term complications ( p = 0.005) but similar lengths of hospital stay (p = 0.093), rate of perioperative complications ( p = 0.487) and EWL% at 1 year of follow-up compared to RSG. Conclusions RSGs had shorter surgical times and a lower incidence of longterm complications when compared with RGBs. These results appear to be similar to those studies reporting the laparoscopic approach. Copyright © 2014 John Wiley & Sons, Ltd. Keywords
robotic; bypass; sleeve; gastric; bariatric; surgery
Introduction
Accepted: 1 September 2014
Copyright © 2014 John Wiley & Sons, Ltd.
Increased rates of obesity within the USA continue to be a high-priority topic within the medical community. Conventional methods of diet, exercise and medication for weight control have shown modest results; however, none of these methods has, to date, produced such impressive results for controlling obesity and its comorbidities as bariatric surgery (1). Laparoscopic roux-en-Y gastric bypass (LGB) is currently the bariatric procedure of choice; however, more recently there has been a surge in popularity in laparoscopic sleeve gastrectomy (LSG), due to its restrictive nature and endocrine benefits (2), making both of these procedures the most common bariatric surgeries performed worldwide (3). To date, many publications have compared LGB and LSG, showing advantages and disadvantages of each procedure. The benefits seen with LGB have been widely tested; however, isolated sleeve gastrectomy as a primary procedure for weight loss is a fairly new concept; its finding has
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shown significant outcomes for obese patients in terms of excess weight loss percentage (EWL%) and improvement of comorbidities (4,5). In 2000, the Federal Drug Administration approved the use of the da Vinci robot surgical system within general laparoscopic surgery (6). Soon thereafter, the da Vinci robot was incorporated into bariatric surgery because of its advantages, i.e. three-dimensional (3D) visualization, instrument articulation and improved surgeon ergonomics. With the introduction of the robotic platform, novel approaches and modifications to the standard LGB and LSG were developed; however, no published reports have compared these two bariatric procedures using robotic technology. Therefore, we hypothesize that robotic technology used during gastric bypass and sleeve gastrectomy could have similar outcomes to those observed during the laparoscopic approaches. The primary purpose of this study was therefore to compare our experience in RGB and RSG, and secondly to compare our robotic procedures with outcomes published in the literature using the laparoscopic approach.
Materials and methods We retrospectively collected, under Institutional Review Board (IRB) approval, RSG and RGB data from September 2009–June 2012 and August 2009–May 2012, respectively. All procedures were performed at a single surgical centre (South Miami Hospital, South Miami, FL, USA) by two surgeons, each with previous experience in laparoscopic (1000 cases) as well as robotic surgery (400 cases). The surgical team consisted of one senior attending surgeon, a bedside surgeon (surgical assistant), one anaesthesiologist, one scrub nurse, one operating room circulating nurse and, in most of the cases, one minimally invasive /bariatric surgery fellow. The inclusion criteria were: BMI ≥ 35 kg/m2 with the presence of a significant comorbidity, or BMI ≥ 40 kg/m2, in patients who underwent either a sleeve gastrectomy or a gastric bypass surgery as an initial bariatric operative procedure. No patients with previous bariatric surgery or revisional procedures were included. All of the robotic procedures were completed using the da Vinci® surgical system (Intuitive Surgical, Sunnyvale, CA, USA). Information was collected, focusing on patient demographics, comorbidities, previous abdominal surgeries, surgical times, lengths of hospital stay, preoperative BMIs, perioperative complications, long-term complications, excess weight loss percentages (EWL%) and postoperative BMIs. Perioperative complications were defined as any complication that presented during the intraoperative course or within 30 days after the surgery, while long-term Copyright © 2014 John Wiley & Sons, Ltd.
complications were defined as any other complication observed during the follow-up period; the mean follow-up for RSG was 15.9 months and for RGB it was 21.1 months. Bleeding was defined as the presence of at least one of the following: (a) patient requiring a blood transfusion; (b) return to operating room to control bleeding; or (c) percutaneous drainage of a haematoma. For the evaluation of EWL% and postoperative BMI, the follow up was achieved at < 1, 1–3, > 3–6, > 6–9, > 9–12, > 12–18 and > 18 months after surgery.
Preoperative evaluation Once the patients had been educated about the options available, they were evaluated individually and informed consent obtained. Patients with BMI ≥ 50 kg/m2 were placed on a low carbohydrate/high protein diet preoperatively for 2 weeks. All patients also received preoperative antibiotics and chemical deep vein thrombosis (DVT) prophylaxis (enoxaparin 40 mg subcutaneous BID), which was continued for 14 days after surgery. In addition, sequential compression devices and early ambulation were carried out on all the patients.
Surgical technique Incision, port placement and docking time For both RSG and RGB, the patient was placed in a 15° reverse Trendelenburg position. Trocar positioning and docking were similar in both procedures (Figure 1). A midline supra-umbilical or umbilical vertical incision was performed and pneumoperitoneum (12–15 mmHg) was created using a Veress needle or an optical trocar
Figure 1. Trocar position during robotic bariatric surgery: 5, 5 mm port; 10, 10 mm port Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
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(ENDOPATH® Xcel Ethicon). A 12 mm trocar was placed into the abdomen, followed by placement of a 30° laparoscope camera into this trocar. At this time, a visual inspection of the intra-abdominal cavity was performed. An additional three trocars (one 5 mm robotic trocar in the right subcostal region, one 12 mm laparoscopic trocar in the right mid axillary region (assistant port) and one 5 mm robotic trocar in the left subcostal region) were placed under direct camera visualization, along with a Nathanson® hook liver retractor (Mediflex Surgical Products) placed via a subxiphoid incision. We used 8 mm robotic instruments initially, but early in our experience we progressed to 5 mm. If any intra-abdominal adhesions prevented placement of the trocars, lysis of these adhesions took place laparoscopically at this time. If the trocars could be placed and the robot docked, the lysis of adhesions was done robotically. Robotic gastric bypass During the RGB, prior to robot docking, we identified the ligament of Treitz laparoscopically and measured 25 cm distally, at which point we marked with a suture the place where the transection would be performed. Subsequently, the robot was brought directly over the patient’s head and docked. At this moment the main surgeon moved over to the console. The laparoscopically stitch-marked biliopancreatic limb was transected with a linear stapler (Echelon Endopath™, Ethicon Endosurgery Inc.) loaded with a white cartridge (45 mm) through the assistant port, leaving the stitch on the alimentary limb. The alimentary limb was measured to be 150 cm in length. The internal part of the jejuno–jejunal anastomosis between the alimentary and biliopancreatic limbs was created using a white cartridge, then the enterotomy was closed with white reloads and reinforced with one layer of running suture (Vycril 2-0). Next, the lesser omentum was opened and the retrogastric space entered for transection across the stomach, 3–4 cm distally from the gastroesophageal junction, using one horizontal application with a 45 mm stapler (blue). Completion of the gastric pouch was made with two or three vertical applications with 45 mm (blue) toward the angle of His, thus separating the pouch from the distal gastric remnant. We did not use a bogie for creation of the gastric pouch. The pouch was sized by the horizontal transection just below the left gastric artery and the vertical transection in line with the angle of His, creating a rectangular pouch. Next, the alimentary limb is brought superiorly in an antegastric–antecolic fashion and the gastro-jejunal anastomosis is created side-to-side, using 20–30 mm of the Endo-GIA stapler. Closure of the enterotomy in performed with two layers of 2-0 Vicryl sutures in a running fashion. In this series of patients, one attending surgeon preferred bioabsorbable material (Peri-strips Dry®, Synovis Surgical Copyright © 2014 John Wiley & Sons, Ltd.
Innovations) as reinforcement to the staple line (38.2% of the cases), while the other attending surgeon favoured fibrin glue application (Evicel® Fibrin Sealant, Ethicon; 61.8% of the cases). Mesenteric defects were not closed in this series. Robotic sleeve gastrectomy For RSGs, the greater curvature of the stomach was divided, in most of the cases with the use of a Harmonic Scalpel (Ethicon Endo-Surgery) or, more recently, with use of an Endowrist® One™ Vessel Sealer (Intuitive Surgical). If a hiatal hernia was found, the repair took place at this time by exposing the left crus and later continuing with the complete hiatus. Once the hiatus, crura and oesophagus were identified, two or three figureof-eight stitches with non-absorbable sutures were placed, using the robotic instruments, while the assistant retracted the intrabdominal structures. Resection of the stomach was started 4–6 cm from the pylorus, with sequential transections using a linear stapler (Echelon Endopath™, Ethicon Endo-Surgery) through the assistant port. For the first two or three applications in the antral area, green cartridges (45 mm) were utilized, then blue (45 mm) for the three or four remaining transections to reach the angle of His. The anaesthesiologist was positioned over the left side of the patient’s head and from this position he managed a 38-Fr bougie (Gastric Calibration Tube®, Ethicon) in the stomach. Bogie calibration was only achieved for RSG. In this series, the staple line was reinforced with oversewing plus fibrin glue (Evicel® Fibrin Sealant, Ethicon) in 52% of the cases, oversewn alone in 40%, and bioabsorbable-buttressed material (Peri-strips Dry) in 8%. The resected stomach was then delivered through one of the 12 mm ports.
Undocking time In all of the RSG and RGB cases, an intraoperative upper endoscopy was performed in unison with a pneumatic air test to evaluate for the possible presence of any staple line air leaks, strictures or bleeds. The upper endoscopy was performed via access over the left side of the patient’s head. Finally, the robot was undocked, the trocars removed and the fascia and skin incisions closed in routine fashion.
Postoperative evaluation All patients were transferred from the recovery room to the hospital floor for post-operative monitoring. The following morning, every patient underwent an upper gastrointestinal series with water-soluble contrast to check for any staple line leaks or narrowing. If the test Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
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was satisfactory, the patient was started on a clear liquid diet. Patients without associated complications were discharged home on postoperative day 2 and instructed to follow a clear liquid and full liquid diet for the next 2 weeks. Solid diet with normal food was allowed after 1 month. Postoperative follow-up occurred at 1 week, 1 month, 4 months, 8 months and 12 months after surgery and every 6 months thereafter.
Statistical analysis Descriptive statistics were presented as average ± stanndard deviation (SD) and range for continuous variables and proportions for categorical variables. Comparisons between groups were performed using the χ 2 test for proportions, Student’s t-test for continuous variables or a Mann–Whitney test when the distributions were significantly asymmetrical or the numeric variables ordinal; p < 0.05 was considered to indicate statistical significance. Learning curves were plotted as operating time in relation to sequential case number. Learning was characterized by the minimum number of cases after which operating time remained below 4 h. We also noted any trends or plateaux evident by visual assessment.
Results This study evaluated a total of 299 patients, 134 RSGs and 165 RGBs. Demographics, comorbidities and operative results are shown in Tables 1 and 2. A total of four complications occurred in our RSG group: three perioperative, which consisted of two thrombotic events, both treated with anticoagulation (one pulmonary embolism and one superior mesenteric vein thrombosis), and one episode of bleeding from the staple line that required re-operation. The single long-term complication seen with RSG was a gastric torsion, which initially required
dilatations, then eventually diagnostic laparoscopy, lysis of adhesions and gastropexy. A total of 18 complications occurred in our RGB group: • Perioperative complications were six, two bleeding events (one required blood transfusion and the other, a haematoma, required percutaneous drainage) and four reoperations: the first patient was returned to surgery due to peritoneal signs, attributed to a small bowel perforation, days after the surgery and was treated with bowel resection and side-to-side anastomosis and discharged 12 days later; the second patient presented 3 days after surgery with an incarcerated incisional hernia from a previous total abdominal hysterectomy; while the third and fourth cases presented with incarcerated hernias in trocar sites. • Long-term complications were 12: one intra-abdominal abscess, treated with antibiotics and observation; five marginal ulcers (four of them were treated with proton Table 2. Operative results and complications RSG
Strictures Marginal ulcer Abscess Incisional hernia Internal hernia Stomach torsion Total
p
139.5 2.7 (±2.4)
< 0.001* 0.093
Perioperative complications 0 0 1 (0.7%) 2 (1.2%) 2 (1.5%) 0 0 4 (2.4%) 3 (2.2%) 6 (3.6%)
0.487#
Mean surgical time (min) Length of hospital stay (days) Leaks Bleeding Thrombotic events Reoperations Total
RGB
107.1 2.3 (±1.7)
Long-term complications 0 0 0 5 (3%) 0 1 (0.6%) 0 1 (0.6%) 0 5 (3%) 1 (0.7%) 0 1 (0.7%) 12 (7.2%)
0.005##
*Statistically significant. # No statistical difference between groups. ## Statistically significant difference between groups.
Table 1. Patient demographics and comorbidities RSG (134 patients)
RGB (165 patients)
p
Mean age (years ± SD) 43.1 (±12.6) (range 14–79) 44.7 (±13.3) (range 14–71) 0.285 2 Mean initial BMI (kg/m ± SD) 45 (±7.1) (range 33.3–77) 47.4 (±9.8) (range 34.9–139.1) 0.013* Mean initial weight (lb ± SD) 274.5 (±82.7) (range 186.2–616) 294.2 (±65.1) (range 181.8–620.4) 0.130 Gender (female) 89 (66.4%) 111 (67.3%) 0.876 Patients with at least one previous abdominal surgery 62 (46.3%) 80 (48.5%) 0.557 Diabetes mellitus 43 (32.1%) 72 (43.6%) 0.040* Hypertension 74 (55.2%) 95 (57.6%) 0.685 Obstructive sleep apnoea 58 (43.3%) 56 (39.3%) 0.100 Hyperlipidaemia 37 (27.6%) 53 (32.1%) 0.398 Hypothyroidism 3 (2.2%) 27 (16.4%) < 0.001* GERD 8 (6%) 30 (18.2%) < 0.002* *Statistically significant. Copyright © 2014 John Wiley & Sons, Ltd.
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pump inhibitors and observation and one required laparoscopic repair with an omental patch for perforation); five internal hernias that required laparoscopic reduction and closure of the defect; and lastly, one incisional hernia that was treated with elective surgery. In order to determine weight loss outcomes, postoperative BMI and %EWL were calculated in both groups at < 1, 1–3, > 3–6, > 6–9, > 9–12, > 12–18 and > 18 months postoperatively. The results appeared to be similar for the RSG and RGB groups (Table 3, Figure 2). As can be seen in Table 3, the percentage of patients seen at follow-up decreased in both groups at a similar rate ( χ 2 = 8.753, p = 0.188), indicating no differential attrition. The average initial weight and BMI was not significantly different between the groups or in the different follow-up periods.
Lastly, the learning curve for surgical time was evaluated in both groups, showing an initial decrease in surgical time as experience was gained. Surgical time for RSGs remained below 4 h after 42 cases, while RGBs required 69 cases, suggesting a shorter learning curve. A decreasing trend during the first 30 cases was evident on the RSG plot, but no comparable pattern was apparent for RGB. Even after the 4 h threshold was attained, considerable variability was evident, with times in the ranges 52–224 min for RSG and 67–231 min for RGB (Figure 3).
Discussion Numerous studies with ample numbers have been published describing the improvement of obesity and its
Table 3. Effectiveness of the surgery (all numbers are averages) Follow-up (months)
Procedure
3.6
> 6–9
> 9–12
> 12–18
> 18
Preoperative 50.7 25.3 64.2 32.1 287 275.9 292 294.3 46.1 45.0 46.6 47.9
20.1 24.8 292.1 293.5 47.2 47.2
14.9 24.8 284 303.2 45.4 49.2
8.2 22.4 253.9 274.3 42.2 46.6
Postoperative 220.1 198.3 220.7 207.1 35.4 32.4 35.2 33.6 66.9 77.6 71.4 87.2 44.7 57.7 47.4 56.8
203.1 191.6 32.7 30.8 89.0 102.4 61.9 67.2
193.0 198.4 30.5 32.4 91.0 104.8 64.9 66.5
174.5 168.6 29.1 28.6 79.4 105.7 66.9 75.0
Figure 2. Average postoperative excess of weight lost percentage (EWL%) for both techniques Copyright © 2014 John Wiley & Sons, Ltd.
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Figure 3. Learning curve for robotic gastric bypass: after 69 cases, operating time remained below 4 h. Learning curve for robotic sleeve gastrectomy: after 42 cases, operating time remained below 4 h; the curve also suggests a decreasing trend during the first 30 cases
comorbidities after LSG or LGB. In addition, several authors have tested the benefits and disadvantages of each procedure (6–8). Most published papers argue that LGB continues to be the best procedure for rapid, substantial and sustained weight loss (8). However, some authors have reported similar EWL% results when the two techniques are compared (9,10). Additionally, when resolution of comorbidities is analysed, it appears that LGB has better outcomes regarding improvement of diabetes mellitus and hyperlipidaemia (11,12). In spite of this, LSG continues to grow in popularity, mainly due to three factors: (a) LSG appears to yield fewer complications; (b) it is technically easier, associated with a shorter learning curve and operative time; and (c) it is a less expensive procedure (13,14). In 2012, Fourman and Saber (15) reported a systematic review of 18 studies comparing the benefits of robotic vs laparoscopic surgery within the field of bariatric surgery. They found that the robotic platform is a safe option and that many improvements are seen with its implementation Copyright © 2014 John Wiley & Sons, Ltd.
in bariatric surgery. One of the advantages of the robotic platform is the high-resolution 3D camera, which allows magnification of the operative field up to × 10. In addition, it enables improved visibility and precision while executing difficult segments encountered with traditional laparoscopy, such as intra-corporeal suture during the anastomosis. The elimination of any undesired movements is another important feature of the robot, thanks to an internal tremor filtration, which occurs 1500 times/s, another key asset delivered with the da Vinci robot is the six degrees of freedom, which include pitch (up–down), yaw (left–right), in-and-out motion, rotation of the instrument shaft and the ability to cut and grasp (16); lastly, improved surgeon ergonomics are noteworthy, thus enabling the performance of surgeries with precision and comfort while decreasing the effects of fatigue (17). The incorporation of the da Vinci robot in sleeve gastrectomies is a novel idea, with meager amounts of published data analysing small patient cohorts. In 2011, Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
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Diamantis et al. (18) described their initial experience with RSG on 19 morbidly obese patients. They found that the EWL% at 1 year follow-up was about 65.5% and that there was a mean operative time of 95.5 min, while perioperative complications and mortality rates in the RSG group were both zero. They concluded that RSG is a safe, feasible and efficient technique for the treatment of morbid obesity. Ayloo et al. (19) compared their initial experience of 30 RSG and 39 LSG patients. They found a longer surgical time for RSG when compared to LSG (135 vs 114 min, respectively); they commented that this difference is due to staple line oversewing, which was only performed during RSG. No complications were found in the RSG group and the mean decrease in BMI was about 16 kg/m2 at 1 year follow-up. They ultimately concluded that RSG is a safe procedure for weight loss in morbidly obese patients. With the introduction of robotic surgery to the field of bariatrics, technical modifications and some benefits have been observed for both sleeve gastrectomy and gastric bypass. Such changes could play a role when the two techniques are evaluated; unfortunately, no studies have reported outcomes when the two procedures were matched. Therefore, we compared these two different bariatric surgical procedures (RSG vs RGB) with the use of the da Vinci robotic surgical system. We found that demographics were statistically different in terms of preoperative BMI (45 vs 47.4 kg/m2, p < 0.012) for RSG and RGB, respectively. In addition, the incidence of preoperative comorbidities (diabetes mellitus, hypertension, hyperlipidaemia, gastroesophageal reflux disease) was higher in RGB when compared with RSG (Table 1). All of these differences reflect the selection bias of the patients before surgery, since frequently those patients with higher BMI and presence of comorbidities are encouraged to have a RGB. These findings in preoperative conditions reinforce the general perception amongst bariatric surgeons (that gastric bypass has better outcomes with regard to weight reduction and improvement of comorbidities) (8). Postoperative outcomes showed that the mean surgical time was about 33 min longer in our RGB group vs the RSG group (139.5 vs 106.6 min, respectively; p = < 0.001). The longer calculated mean surgical time was expected, since RSG is only a restrictive procedure that requires simpler intraoperative manoeuvres, while RGB is a restrictive/malabsorptive procedure that requires more complex surgical skills. The same reasons probably influenced the observed learning curve, since RSG showed a faster decrease in operative time as experience was acquired, and a smaller number of cases necessary to stay below 4 h (42 cases for RSG and 69 for RGB). These results suggest that RSG has a shorter learning curve than RGB (Figure 3). These results are similar to other Copyright © 2014 John Wiley & Sons, Ltd.
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laparoscopic series that show learning curves with gastric bypass ranging between 0 to 100 cases (20) and 34 cases for laparoscopic sleeve (21). The learning curves with robotic gastric bypass and sleeve gastrectomy have been much less frequently reported. Similar trends to our study, however, are seen in Renaud et al. (22), who mention 84 cases for RBP, and Villalonga et al. (23), who report 20 for RSG. It is important to mention that the method used to obtain the learning curves may differ among authors, and the learning curve shown in this study is a result of the combined participation of two surgeons. When perioperative complication rates were compared, we did not observe differences between procedures (2.2% for RSG vs 3.6% for RGB; p = 0.487); however, when long-term complications were evaluated, a statistically significant difference was found favouring RSG (0.7% for RSG vs 7.2% for RGB; p = 0.005; Table 2). The reasons are probably attributable to the procedure itself, since some of the mentioned complications (internal hernias and marginal ulcers) are considered typical of gastric bypass and are not seen in RSG; and the longer followup seen in the RGB group (21.1 vs 15.9 months). When a comparison is performed with the published literature, our results appear to be similar to the large laparoscopic series by the Michigan Bariatric Surgery Collaborative, which identified a complication rate of 10% for LGB and 6.3% for LSG within 30 days of surgery (24), and Chouillard et al. (25), who found 20.5% vs 6.5% minor complications after LGB and LSG, respectively. We believe that it is important to mention that the leak rate, which is one of the most feared complications of both procedures, was zero in both our groups. In a large systematic review of 4888 sleeve gastrectomies, the estimated rate of leaks was 2.4%, while a multivariate analysis of 3000 bypasses reported 3.2%.(26,27) Postoperative results for our RSG vs RGB cohorts, in terms of weight reduction as a function of time, is demonstrated in Table 3. In 20.1% of RSG patients and 24.8% of RGB patients, we were able to obtain data at 1 year of follow-up, while at > 18 months follow-up data were only available in 8.2% of RSGs and 22.4% of RGBs. At 1 year, the amounts of weight loss were 89 and 102.4 lb; the postoperative BMIs were 32.7 and 30.8 kg/m2; and the % EWLs were 61.9% and 67.2% for RSG and RGB, respectively. These results show no difference in terms of weight reduction, new BMI and EWL% between the two techniques at 1 year of follow-up (Figure 2). This similitude found in our cohorts with the use of the robot is comparable with other experiences that mention no differences between LGB and LSG in terms of excess weight loss percentage (EWL%) (28). We acknowledge that this study has the following main limitations: (a) the retrospective design decreases the statistical power to our analysis; (b) since two surgeons participated Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
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in this series, surgeon bias could have influenced the results, i.e. the method used to reinforced the staple line and the individual surgical skills; (c) when weight reduction was analysed, a relatively small percentage of patients were evaluated in the long term; and (d) there exists a preoperative selection bias in procedure choice, based on BMI and presence of comorbidities, which could influence outcomes. Based on these results, it appears that robotic bariatric surgery has similar outcomes to those of its counterpart, laparoscopy. However, in the authors’ experience benefits include more comfort for the surgeon during the procedure, longer robotic arms able to reach distant targets in larger patients, even if trocars are placed at the level of the umbilicus, as well as technological advances, such as 3D view, ergonomic arms and elimination of tremor. Our experience has demonstrated that all these features have a positive impact when intracorporeal suturing is performed. In this study, we did not employ the hand-sewn technique during the creation of the gastro-jejunal anastomosis; however, we used intracorporeal suturing to reinforce the jenunostomy and the staple line during the sleeve procedure, and for closing the opening of the gastro-jejunal anastomosis; in those steps we have noticed valuable benefits with the robotic ergonomicity. Although not attempted in this study, we think that is possible to create totally both jejunal and gastro-jejunal anastomoses with the hand-sewn technique, and major benefits could be observed, such as those previously reported (6,29,30). When the robot is used, we believe that major benefits can be observed with ’more complex’ procedures, such as bariatric revisions; nevertheless, our recommendation is to use the robot in routine surgery (as presented in this paper) in order to gain the experience to perform ’more complex’ operations successfully. Some limitations may be noticeable early in one’s robotic experience, such as the time required for trocar placement and docking, and the size of the device, which could limit movement through the operating room; however, the time can be compensated for as experience progresses. The issue of moving the robot cart in a small operating room can be resolved by simply rotating the patient’s bed toward the robot before the surgery begins. Early in one’s experience, another limitation of robotic surgery could be the lack of haptic feedback. This problem can be overcome by utilizing the weaker 5 mm instruments on the robot as compared to their stronger 8 mm counterparts. This avoids placing excessive pressure on the tissues while they are handled.
Conclusions RGB has a longer surgical time, longer learning curve and a higher incidence of long-term complications than RSG. Copyright © 2014 John Wiley & Sons, Ltd.
RSGs and RGBs showed similar EWL%, although longerterm follow-up is needed for both groups to further substantiate these findings. Finally, the robotic approach to gastric bypass and sleeve gastrectomy has safety profiles and short-term weight losses similar to the laparoscopic approach, as published in the literature.
Acknowledgements We are grateful to Carmen Rodriguez RN, Assistant Vice President of Perioperative Services at South Miami Hospital; Michelle Gallas PhD, Staff at our Centre for Research and Grants, and Gail R. Walker, statistician.
Conflict of interest Dr Anthony Michael Gonzalez and Dr Jorge Rafael Rabaza are both speakers and proctors for Intuitive Surgical Inc., Sunnyvale, CA, USA; Dr Radomir Kosanovic, Dr Rey Jesús Romero, Dr Charan Donkor and Dr Armando Sarasua have no conflicts of interest or financial ties to disclose.
Funding No specific funding.
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Robotic sleeve gastrectomy vs robotic gastric bypass 8. Hutter MM, Schirmer BD, Jones DB, et al. First report from the American College of Surgeons Bariatric Surgery Center Network: laparoscopic sleeve gastrectomy has morbidity and effectiveness positioned between the band and the bypass. Ann Surg 2011; 254: 410–420. 9. Vidal P, Ramón JM, Goday A, et al. Laparoscopic gastric bypass versus laparoscopic sleeve gastrectomy as a definitive surgical procedure for morbid obesity. Mid-term results. Obes Surg 2013; 23: 292–299. 10. Yaghoubian A, Tolan A, Stabile BE, et al. Laparoscopic roux-en-Y gastric bypass and sleeve gastrectomy achieve comparable weight loss at 1 year. Am Surg 2012; 78: 1325–1328. 11. Li P, Fu P, Chen J, et al. Laparoscopic roux-en-Y gastric bypass vs laparoscopic sleeve gastrectomy for morbid obesity and diabetes mellitus: a meta-analysis of sixteen recent studies. Hepatogastroenterology 2013; 60: 132–137. 12. Benaiges D, Flores-Le-Roux JA, Pedro-Botet J, et al. Impact of restrictive (sleeve gastrectomy) vs hybrid bariatric surgery (rouxen-Y gastric bypass) on lipid profile. Obes Surg 2012; 22: 1268–1275. 13. Lim DM, Taller J, Bertucci W, et al. Comparison of laparoscopic sleeve gastrectomy to laparoscopic roux-en-Y gastric bypass for morbid obesity in a military institution. Surg Obes Relat Dis 2014; 10: 269–276. 14. Nguyen NT, Nguyen B, Gebhart A, et al. Changes in the make-up of bariatric surgery: a national increase in use of laparoscopic sleeve gastrectomy. J Am Coll Surg 2013; 216: 252–257. 15. Fourman MM, Saber AA. Robotic bariatric surgery. A systematic review. Surg Obes Relat Dis 2012; 8: 483–488. 16. Dion YM, Gaillard F. Visual integration of data and basic motor skills under laparoscopy influence of 2D and 3D video-camera systems. Surg Endosc 1997; 11: 995–1000. 17. Hubert N, Gilles M, Desbrosses K, et al. Ergonomic assessment of the surgeon’s physical workload during standard and robotic assisted laparoscopic procedures. Int J Med Robot 2013; 9: 142–147. 18. Diamantis T, Alexandrou A, Nikiteas N, et al. Initial experience with robotic sleeve gastrectomy for morbid obesity. Obes Surg 2011; 21: 1172–1179. 19. Ayloo S, Buchs NC, Addeo P, et al. Robot-assisted sleeve gastrectomy for super-morbidly obese patients. J Laparoendosc Adv Surg Tech A 2011; 21: 295–299.
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283 20. Zevin B, Aggarwal R, Grantcharov TP. Simulation-based training and learning curves in laparoscopic roux-en-Y gastric bypass. Br J Surg 2012; 99: 887–895. 21. Zacharoulis D, Sioka E, Papamargaritis D, et al. Influence of the learning curve on safety and efficiency of laparoscopic sleeve gastrectomy. Obes Surg 2012; 22: 411. 22. Renaud M, Reibel N, Zarnegar R, et al. Multifactorial analysis of the learning curve for totally robotic roux-en-Y gastric bypass. Obes Surg 2013; 23: 173–160. 23. Villalonga R, Fort JM, Gonzalez O, et al. The initial learning curve for robot-assisted sleeve gastrectomy: a surgeon’s experience while introducing the robotic technology in a bariatric surgery department. Minim Invasive Surg 2012; 2012: 347131. 24. Carlin AM, Zeni TM, English WJ, et al. for the Michigan Bariatric Surgery Collaborative. The comparative effectiveness of sleeve gastrectomy, gastric bypass and adjustable gastric banding procedures for the treatment of morbid obesity. Ann Surg 2013; 257: 791–797. 25. Chouillard EK, Karaa A, Elkhoury M, et al. Intercontinental Society of Natural Orifice, Endoscopic, and Laparoscopic Surgery (i-NOELS). Surg Obes Relat Dis 2011; 7: 500–505. 26. Aurora AR, Khaitan L, Saber AA. Sleeve gastrectomy and the risk of leak: a systematic review of 4888 patients. Surg Endosc 2012; 26: 1509–1515. 27. Fernandez AZ, Jr, DeMaria EJ, Tichansky DS, et al. Experience with over 3000 open and laparoscopic bariatric procedures: multivariate analysis of factors related to leak and resultant mortality. Surg Endosc 2004; 18: 193–197. 28. Benaiges D, Goday A, Ramon JM, et al. Laparoscopic sleeve gastrectomy and laparoscopic gastric bypass are equally effective for reduction of cardiovascular risk in severely obese patients at one year of follow-up. Surg Obes Relat Dis 2011; 7: 575–580. 29. Higa KD, Ho T, Boone KB. Laparoscopic roux-en-Y gastric bypass: technique and 3-year follow-up. J Laparoendosc Adv Surg Tech A 2001; 11: 377–382. 30. Ayloo SM, Addeo P, Buchs NC, et al. Robot-assisted versus laparoscopic roux-en-Y gastric bypass: is there a difference in outcomes? World J Surg 2011; 35: 637–642.
Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
ARTICLE
A comparative retrospective study of robotic sleeve gastrectomy vs robotic gastric bypass
Radomir Kosanovic1 Rey Jesús Romero1 Charan Donkor1,2 Armando Sarasua1 Jorge Rafael Rabaza1,2 Anthony Michael Gonzalez1,2* 1
Department of General and Bariatric Surgery, South Miami Hospital, Baptist Health South Florida, Miami, FL, USA
2
Florida International University, Herbert Wertheim College of Medicine Florida, Miami, FL, USA *Correspondence to: A. M. Gonzalez, Florida International University, Herbert Wertheim College of Medicine Florida, 7800 SW 87 Avenue, Suite B-210, Miami, FL 33173, USA. E-mail: [email protected]
Abstract Background The introduction of the robotic platform to bariatric surgery has brought forth a novel approach, with modifications to the standard laparoscopic sleeve gastrectomy (LSG) and laparoscopic gastric bypass (LGB). The purpose of this study was to match robotic gastric bypass (RGB) vs robotic sleeve gastrectomy (RSG) and compare them to those observed with the laparoscopic platform. Methods A retrospective data collection of RSGs and RGBs from a single institution was performed. Groups were compared. Results This study included 134 RSG and 165 RGB patients. RGB has a longer surgical time (p < 0.001) and a higher incidence of long-term complications ( p = 0.005) but similar lengths of hospital stay (p = 0.093), rate of perioperative complications ( p = 0.487) and EWL% at 1 year of follow-up compared to RSG. Conclusions RSGs had shorter surgical times and a lower incidence of longterm complications when compared with RGBs. These results appear to be similar to those studies reporting the laparoscopic approach. Copyright © 2014 John Wiley & Sons, Ltd. Keywords
robotic; bypass; sleeve; gastric; bariatric; surgery
Introduction
Accepted: 1 September 2014
Copyright © 2014 John Wiley & Sons, Ltd.
Increased rates of obesity within the USA continue to be a high-priority topic within the medical community. Conventional methods of diet, exercise and medication for weight control have shown modest results; however, none of these methods has, to date, produced such impressive results for controlling obesity and its comorbidities as bariatric surgery (1). Laparoscopic roux-en-Y gastric bypass (LGB) is currently the bariatric procedure of choice; however, more recently there has been a surge in popularity in laparoscopic sleeve gastrectomy (LSG), due to its restrictive nature and endocrine benefits (2), making both of these procedures the most common bariatric surgeries performed worldwide (3). To date, many publications have compared LGB and LSG, showing advantages and disadvantages of each procedure. The benefits seen with LGB have been widely tested; however, isolated sleeve gastrectomy as a primary procedure for weight loss is a fairly new concept; its finding has
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shown significant outcomes for obese patients in terms of excess weight loss percentage (EWL%) and improvement of comorbidities (4,5). In 2000, the Federal Drug Administration approved the use of the da Vinci robot surgical system within general laparoscopic surgery (6). Soon thereafter, the da Vinci robot was incorporated into bariatric surgery because of its advantages, i.e. three-dimensional (3D) visualization, instrument articulation and improved surgeon ergonomics. With the introduction of the robotic platform, novel approaches and modifications to the standard LGB and LSG were developed; however, no published reports have compared these two bariatric procedures using robotic technology. Therefore, we hypothesize that robotic technology used during gastric bypass and sleeve gastrectomy could have similar outcomes to those observed during the laparoscopic approaches. The primary purpose of this study was therefore to compare our experience in RGB and RSG, and secondly to compare our robotic procedures with outcomes published in the literature using the laparoscopic approach.
Materials and methods We retrospectively collected, under Institutional Review Board (IRB) approval, RSG and RGB data from September 2009–June 2012 and August 2009–May 2012, respectively. All procedures were performed at a single surgical centre (South Miami Hospital, South Miami, FL, USA) by two surgeons, each with previous experience in laparoscopic (1000 cases) as well as robotic surgery (400 cases). The surgical team consisted of one senior attending surgeon, a bedside surgeon (surgical assistant), one anaesthesiologist, one scrub nurse, one operating room circulating nurse and, in most of the cases, one minimally invasive /bariatric surgery fellow. The inclusion criteria were: BMI ≥ 35 kg/m2 with the presence of a significant comorbidity, or BMI ≥ 40 kg/m2, in patients who underwent either a sleeve gastrectomy or a gastric bypass surgery as an initial bariatric operative procedure. No patients with previous bariatric surgery or revisional procedures were included. All of the robotic procedures were completed using the da Vinci® surgical system (Intuitive Surgical, Sunnyvale, CA, USA). Information was collected, focusing on patient demographics, comorbidities, previous abdominal surgeries, surgical times, lengths of hospital stay, preoperative BMIs, perioperative complications, long-term complications, excess weight loss percentages (EWL%) and postoperative BMIs. Perioperative complications were defined as any complication that presented during the intraoperative course or within 30 days after the surgery, while long-term Copyright © 2014 John Wiley & Sons, Ltd.
complications were defined as any other complication observed during the follow-up period; the mean follow-up for RSG was 15.9 months and for RGB it was 21.1 months. Bleeding was defined as the presence of at least one of the following: (a) patient requiring a blood transfusion; (b) return to operating room to control bleeding; or (c) percutaneous drainage of a haematoma. For the evaluation of EWL% and postoperative BMI, the follow up was achieved at < 1, 1–3, > 3–6, > 6–9, > 9–12, > 12–18 and > 18 months after surgery.
Preoperative evaluation Once the patients had been educated about the options available, they were evaluated individually and informed consent obtained. Patients with BMI ≥ 50 kg/m2 were placed on a low carbohydrate/high protein diet preoperatively for 2 weeks. All patients also received preoperative antibiotics and chemical deep vein thrombosis (DVT) prophylaxis (enoxaparin 40 mg subcutaneous BID), which was continued for 14 days after surgery. In addition, sequential compression devices and early ambulation were carried out on all the patients.
Surgical technique Incision, port placement and docking time For both RSG and RGB, the patient was placed in a 15° reverse Trendelenburg position. Trocar positioning and docking were similar in both procedures (Figure 1). A midline supra-umbilical or umbilical vertical incision was performed and pneumoperitoneum (12–15 mmHg) was created using a Veress needle or an optical trocar
Figure 1. Trocar position during robotic bariatric surgery: 5, 5 mm port; 10, 10 mm port Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
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(ENDOPATH® Xcel Ethicon). A 12 mm trocar was placed into the abdomen, followed by placement of a 30° laparoscope camera into this trocar. At this time, a visual inspection of the intra-abdominal cavity was performed. An additional three trocars (one 5 mm robotic trocar in the right subcostal region, one 12 mm laparoscopic trocar in the right mid axillary region (assistant port) and one 5 mm robotic trocar in the left subcostal region) were placed under direct camera visualization, along with a Nathanson® hook liver retractor (Mediflex Surgical Products) placed via a subxiphoid incision. We used 8 mm robotic instruments initially, but early in our experience we progressed to 5 mm. If any intra-abdominal adhesions prevented placement of the trocars, lysis of these adhesions took place laparoscopically at this time. If the trocars could be placed and the robot docked, the lysis of adhesions was done robotically. Robotic gastric bypass During the RGB, prior to robot docking, we identified the ligament of Treitz laparoscopically and measured 25 cm distally, at which point we marked with a suture the place where the transection would be performed. Subsequently, the robot was brought directly over the patient’s head and docked. At this moment the main surgeon moved over to the console. The laparoscopically stitch-marked biliopancreatic limb was transected with a linear stapler (Echelon Endopath™, Ethicon Endosurgery Inc.) loaded with a white cartridge (45 mm) through the assistant port, leaving the stitch on the alimentary limb. The alimentary limb was measured to be 150 cm in length. The internal part of the jejuno–jejunal anastomosis between the alimentary and biliopancreatic limbs was created using a white cartridge, then the enterotomy was closed with white reloads and reinforced with one layer of running suture (Vycril 2-0). Next, the lesser omentum was opened and the retrogastric space entered for transection across the stomach, 3–4 cm distally from the gastroesophageal junction, using one horizontal application with a 45 mm stapler (blue). Completion of the gastric pouch was made with two or three vertical applications with 45 mm (blue) toward the angle of His, thus separating the pouch from the distal gastric remnant. We did not use a bogie for creation of the gastric pouch. The pouch was sized by the horizontal transection just below the left gastric artery and the vertical transection in line with the angle of His, creating a rectangular pouch. Next, the alimentary limb is brought superiorly in an antegastric–antecolic fashion and the gastro-jejunal anastomosis is created side-to-side, using 20–30 mm of the Endo-GIA stapler. Closure of the enterotomy in performed with two layers of 2-0 Vicryl sutures in a running fashion. In this series of patients, one attending surgeon preferred bioabsorbable material (Peri-strips Dry®, Synovis Surgical Copyright © 2014 John Wiley & Sons, Ltd.
Innovations) as reinforcement to the staple line (38.2% of the cases), while the other attending surgeon favoured fibrin glue application (Evicel® Fibrin Sealant, Ethicon; 61.8% of the cases). Mesenteric defects were not closed in this series. Robotic sleeve gastrectomy For RSGs, the greater curvature of the stomach was divided, in most of the cases with the use of a Harmonic Scalpel (Ethicon Endo-Surgery) or, more recently, with use of an Endowrist® One™ Vessel Sealer (Intuitive Surgical). If a hiatal hernia was found, the repair took place at this time by exposing the left crus and later continuing with the complete hiatus. Once the hiatus, crura and oesophagus were identified, two or three figureof-eight stitches with non-absorbable sutures were placed, using the robotic instruments, while the assistant retracted the intrabdominal structures. Resection of the stomach was started 4–6 cm from the pylorus, with sequential transections using a linear stapler (Echelon Endopath™, Ethicon Endo-Surgery) through the assistant port. For the first two or three applications in the antral area, green cartridges (45 mm) were utilized, then blue (45 mm) for the three or four remaining transections to reach the angle of His. The anaesthesiologist was positioned over the left side of the patient’s head and from this position he managed a 38-Fr bougie (Gastric Calibration Tube®, Ethicon) in the stomach. Bogie calibration was only achieved for RSG. In this series, the staple line was reinforced with oversewing plus fibrin glue (Evicel® Fibrin Sealant, Ethicon) in 52% of the cases, oversewn alone in 40%, and bioabsorbable-buttressed material (Peri-strips Dry) in 8%. The resected stomach was then delivered through one of the 12 mm ports.
Undocking time In all of the RSG and RGB cases, an intraoperative upper endoscopy was performed in unison with a pneumatic air test to evaluate for the possible presence of any staple line air leaks, strictures or bleeds. The upper endoscopy was performed via access over the left side of the patient’s head. Finally, the robot was undocked, the trocars removed and the fascia and skin incisions closed in routine fashion.
Postoperative evaluation All patients were transferred from the recovery room to the hospital floor for post-operative monitoring. The following morning, every patient underwent an upper gastrointestinal series with water-soluble contrast to check for any staple line leaks or narrowing. If the test Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
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was satisfactory, the patient was started on a clear liquid diet. Patients without associated complications were discharged home on postoperative day 2 and instructed to follow a clear liquid and full liquid diet for the next 2 weeks. Solid diet with normal food was allowed after 1 month. Postoperative follow-up occurred at 1 week, 1 month, 4 months, 8 months and 12 months after surgery and every 6 months thereafter.
Statistical analysis Descriptive statistics were presented as average ± stanndard deviation (SD) and range for continuous variables and proportions for categorical variables. Comparisons between groups were performed using the χ 2 test for proportions, Student’s t-test for continuous variables or a Mann–Whitney test when the distributions were significantly asymmetrical or the numeric variables ordinal; p < 0.05 was considered to indicate statistical significance. Learning curves were plotted as operating time in relation to sequential case number. Learning was characterized by the minimum number of cases after which operating time remained below 4 h. We also noted any trends or plateaux evident by visual assessment.
Results This study evaluated a total of 299 patients, 134 RSGs and 165 RGBs. Demographics, comorbidities and operative results are shown in Tables 1 and 2. A total of four complications occurred in our RSG group: three perioperative, which consisted of two thrombotic events, both treated with anticoagulation (one pulmonary embolism and one superior mesenteric vein thrombosis), and one episode of bleeding from the staple line that required re-operation. The single long-term complication seen with RSG was a gastric torsion, which initially required
dilatations, then eventually diagnostic laparoscopy, lysis of adhesions and gastropexy. A total of 18 complications occurred in our RGB group: • Perioperative complications were six, two bleeding events (one required blood transfusion and the other, a haematoma, required percutaneous drainage) and four reoperations: the first patient was returned to surgery due to peritoneal signs, attributed to a small bowel perforation, days after the surgery and was treated with bowel resection and side-to-side anastomosis and discharged 12 days later; the second patient presented 3 days after surgery with an incarcerated incisional hernia from a previous total abdominal hysterectomy; while the third and fourth cases presented with incarcerated hernias in trocar sites. • Long-term complications were 12: one intra-abdominal abscess, treated with antibiotics and observation; five marginal ulcers (four of them were treated with proton Table 2. Operative results and complications RSG
Strictures Marginal ulcer Abscess Incisional hernia Internal hernia Stomach torsion Total
p
139.5 2.7 (±2.4)
< 0.001* 0.093
Perioperative complications 0 0 1 (0.7%) 2 (1.2%) 2 (1.5%) 0 0 4 (2.4%) 3 (2.2%) 6 (3.6%)
0.487#
Mean surgical time (min) Length of hospital stay (days) Leaks Bleeding Thrombotic events Reoperations Total
RGB
107.1 2.3 (±1.7)
Long-term complications 0 0 0 5 (3%) 0 1 (0.6%) 0 1 (0.6%) 0 5 (3%) 1 (0.7%) 0 1 (0.7%) 12 (7.2%)
0.005##
*Statistically significant. # No statistical difference between groups. ## Statistically significant difference between groups.
Table 1. Patient demographics and comorbidities RSG (134 patients)
RGB (165 patients)
p
Mean age (years ± SD) 43.1 (±12.6) (range 14–79) 44.7 (±13.3) (range 14–71) 0.285 2 Mean initial BMI (kg/m ± SD) 45 (±7.1) (range 33.3–77) 47.4 (±9.8) (range 34.9–139.1) 0.013* Mean initial weight (lb ± SD) 274.5 (±82.7) (range 186.2–616) 294.2 (±65.1) (range 181.8–620.4) 0.130 Gender (female) 89 (66.4%) 111 (67.3%) 0.876 Patients with at least one previous abdominal surgery 62 (46.3%) 80 (48.5%) 0.557 Diabetes mellitus 43 (32.1%) 72 (43.6%) 0.040* Hypertension 74 (55.2%) 95 (57.6%) 0.685 Obstructive sleep apnoea 58 (43.3%) 56 (39.3%) 0.100 Hyperlipidaemia 37 (27.6%) 53 (32.1%) 0.398 Hypothyroidism 3 (2.2%) 27 (16.4%) < 0.001* GERD 8 (6%) 30 (18.2%) < 0.002* *Statistically significant. Copyright © 2014 John Wiley & Sons, Ltd.
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pump inhibitors and observation and one required laparoscopic repair with an omental patch for perforation); five internal hernias that required laparoscopic reduction and closure of the defect; and lastly, one incisional hernia that was treated with elective surgery. In order to determine weight loss outcomes, postoperative BMI and %EWL were calculated in both groups at < 1, 1–3, > 3–6, > 6–9, > 9–12, > 12–18 and > 18 months postoperatively. The results appeared to be similar for the RSG and RGB groups (Table 3, Figure 2). As can be seen in Table 3, the percentage of patients seen at follow-up decreased in both groups at a similar rate ( χ 2 = 8.753, p = 0.188), indicating no differential attrition. The average initial weight and BMI was not significantly different between the groups or in the different follow-up periods.
Lastly, the learning curve for surgical time was evaluated in both groups, showing an initial decrease in surgical time as experience was gained. Surgical time for RSGs remained below 4 h after 42 cases, while RGBs required 69 cases, suggesting a shorter learning curve. A decreasing trend during the first 30 cases was evident on the RSG plot, but no comparable pattern was apparent for RGB. Even after the 4 h threshold was attained, considerable variability was evident, with times in the ranges 52–224 min for RSG and 67–231 min for RGB (Figure 3).
Discussion Numerous studies with ample numbers have been published describing the improvement of obesity and its
Table 3. Effectiveness of the surgery (all numbers are averages) Follow-up (months)
Procedure
3.6
> 6–9
> 9–12
> 12–18
> 18
Preoperative 50.7 25.3 64.2 32.1 287 275.9 292 294.3 46.1 45.0 46.6 47.9
20.1 24.8 292.1 293.5 47.2 47.2
14.9 24.8 284 303.2 45.4 49.2
8.2 22.4 253.9 274.3 42.2 46.6
Postoperative 220.1 198.3 220.7 207.1 35.4 32.4 35.2 33.6 66.9 77.6 71.4 87.2 44.7 57.7 47.4 56.8
203.1 191.6 32.7 30.8 89.0 102.4 61.9 67.2
193.0 198.4 30.5 32.4 91.0 104.8 64.9 66.5
174.5 168.6 29.1 28.6 79.4 105.7 66.9 75.0
Figure 2. Average postoperative excess of weight lost percentage (EWL%) for both techniques Copyright © 2014 John Wiley & Sons, Ltd.
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Figure 3. Learning curve for robotic gastric bypass: after 69 cases, operating time remained below 4 h. Learning curve for robotic sleeve gastrectomy: after 42 cases, operating time remained below 4 h; the curve also suggests a decreasing trend during the first 30 cases
comorbidities after LSG or LGB. In addition, several authors have tested the benefits and disadvantages of each procedure (6–8). Most published papers argue that LGB continues to be the best procedure for rapid, substantial and sustained weight loss (8). However, some authors have reported similar EWL% results when the two techniques are compared (9,10). Additionally, when resolution of comorbidities is analysed, it appears that LGB has better outcomes regarding improvement of diabetes mellitus and hyperlipidaemia (11,12). In spite of this, LSG continues to grow in popularity, mainly due to three factors: (a) LSG appears to yield fewer complications; (b) it is technically easier, associated with a shorter learning curve and operative time; and (c) it is a less expensive procedure (13,14). In 2012, Fourman and Saber (15) reported a systematic review of 18 studies comparing the benefits of robotic vs laparoscopic surgery within the field of bariatric surgery. They found that the robotic platform is a safe option and that many improvements are seen with its implementation Copyright © 2014 John Wiley & Sons, Ltd.
in bariatric surgery. One of the advantages of the robotic platform is the high-resolution 3D camera, which allows magnification of the operative field up to × 10. In addition, it enables improved visibility and precision while executing difficult segments encountered with traditional laparoscopy, such as intra-corporeal suture during the anastomosis. The elimination of any undesired movements is another important feature of the robot, thanks to an internal tremor filtration, which occurs 1500 times/s, another key asset delivered with the da Vinci robot is the six degrees of freedom, which include pitch (up–down), yaw (left–right), in-and-out motion, rotation of the instrument shaft and the ability to cut and grasp (16); lastly, improved surgeon ergonomics are noteworthy, thus enabling the performance of surgeries with precision and comfort while decreasing the effects of fatigue (17). The incorporation of the da Vinci robot in sleeve gastrectomies is a novel idea, with meager amounts of published data analysing small patient cohorts. In 2011, Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
Robotic sleeve gastrectomy vs robotic gastric bypass
Diamantis et al. (18) described their initial experience with RSG on 19 morbidly obese patients. They found that the EWL% at 1 year follow-up was about 65.5% and that there was a mean operative time of 95.5 min, while perioperative complications and mortality rates in the RSG group were both zero. They concluded that RSG is a safe, feasible and efficient technique for the treatment of morbid obesity. Ayloo et al. (19) compared their initial experience of 30 RSG and 39 LSG patients. They found a longer surgical time for RSG when compared to LSG (135 vs 114 min, respectively); they commented that this difference is due to staple line oversewing, which was only performed during RSG. No complications were found in the RSG group and the mean decrease in BMI was about 16 kg/m2 at 1 year follow-up. They ultimately concluded that RSG is a safe procedure for weight loss in morbidly obese patients. With the introduction of robotic surgery to the field of bariatrics, technical modifications and some benefits have been observed for both sleeve gastrectomy and gastric bypass. Such changes could play a role when the two techniques are evaluated; unfortunately, no studies have reported outcomes when the two procedures were matched. Therefore, we compared these two different bariatric surgical procedures (RSG vs RGB) with the use of the da Vinci robotic surgical system. We found that demographics were statistically different in terms of preoperative BMI (45 vs 47.4 kg/m2, p < 0.012) for RSG and RGB, respectively. In addition, the incidence of preoperative comorbidities (diabetes mellitus, hypertension, hyperlipidaemia, gastroesophageal reflux disease) was higher in RGB when compared with RSG (Table 1). All of these differences reflect the selection bias of the patients before surgery, since frequently those patients with higher BMI and presence of comorbidities are encouraged to have a RGB. These findings in preoperative conditions reinforce the general perception amongst bariatric surgeons (that gastric bypass has better outcomes with regard to weight reduction and improvement of comorbidities) (8). Postoperative outcomes showed that the mean surgical time was about 33 min longer in our RGB group vs the RSG group (139.5 vs 106.6 min, respectively; p = < 0.001). The longer calculated mean surgical time was expected, since RSG is only a restrictive procedure that requires simpler intraoperative manoeuvres, while RGB is a restrictive/malabsorptive procedure that requires more complex surgical skills. The same reasons probably influenced the observed learning curve, since RSG showed a faster decrease in operative time as experience was acquired, and a smaller number of cases necessary to stay below 4 h (42 cases for RSG and 69 for RGB). These results suggest that RSG has a shorter learning curve than RGB (Figure 3). These results are similar to other Copyright © 2014 John Wiley & Sons, Ltd.
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laparoscopic series that show learning curves with gastric bypass ranging between 0 to 100 cases (20) and 34 cases for laparoscopic sleeve (21). The learning curves with robotic gastric bypass and sleeve gastrectomy have been much less frequently reported. Similar trends to our study, however, are seen in Renaud et al. (22), who mention 84 cases for RBP, and Villalonga et al. (23), who report 20 for RSG. It is important to mention that the method used to obtain the learning curves may differ among authors, and the learning curve shown in this study is a result of the combined participation of two surgeons. When perioperative complication rates were compared, we did not observe differences between procedures (2.2% for RSG vs 3.6% for RGB; p = 0.487); however, when long-term complications were evaluated, a statistically significant difference was found favouring RSG (0.7% for RSG vs 7.2% for RGB; p = 0.005; Table 2). The reasons are probably attributable to the procedure itself, since some of the mentioned complications (internal hernias and marginal ulcers) are considered typical of gastric bypass and are not seen in RSG; and the longer followup seen in the RGB group (21.1 vs 15.9 months). When a comparison is performed with the published literature, our results appear to be similar to the large laparoscopic series by the Michigan Bariatric Surgery Collaborative, which identified a complication rate of 10% for LGB and 6.3% for LSG within 30 days of surgery (24), and Chouillard et al. (25), who found 20.5% vs 6.5% minor complications after LGB and LSG, respectively. We believe that it is important to mention that the leak rate, which is one of the most feared complications of both procedures, was zero in both our groups. In a large systematic review of 4888 sleeve gastrectomies, the estimated rate of leaks was 2.4%, while a multivariate analysis of 3000 bypasses reported 3.2%.(26,27) Postoperative results for our RSG vs RGB cohorts, in terms of weight reduction as a function of time, is demonstrated in Table 3. In 20.1% of RSG patients and 24.8% of RGB patients, we were able to obtain data at 1 year of follow-up, while at > 18 months follow-up data were only available in 8.2% of RSGs and 22.4% of RGBs. At 1 year, the amounts of weight loss were 89 and 102.4 lb; the postoperative BMIs were 32.7 and 30.8 kg/m2; and the % EWLs were 61.9% and 67.2% for RSG and RGB, respectively. These results show no difference in terms of weight reduction, new BMI and EWL% between the two techniques at 1 year of follow-up (Figure 2). This similitude found in our cohorts with the use of the robot is comparable with other experiences that mention no differences between LGB and LSG in terms of excess weight loss percentage (EWL%) (28). We acknowledge that this study has the following main limitations: (a) the retrospective design decreases the statistical power to our analysis; (b) since two surgeons participated Int J Med Robotics Comput Assist Surg 2015; 11: 275–283. DOI: 10.1002/rcs
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in this series, surgeon bias could have influenced the results, i.e. the method used to reinforced the staple line and the individual surgical skills; (c) when weight reduction was analysed, a relatively small percentage of patients were evaluated in the long term; and (d) there exists a preoperative selection bias in procedure choice, based on BMI and presence of comorbidities, which could influence outcomes. Based on these results, it appears that robotic bariatric surgery has similar outcomes to those of its counterpart, laparoscopy. However, in the authors’ experience benefits include more comfort for the surgeon during the procedure, longer robotic arms able to reach distant targets in larger patients, even if trocars are placed at the level of the umbilicus, as well as technological advances, such as 3D view, ergonomic arms and elimination of tremor. Our experience has demonstrated that all these features have a positive impact when intracorporeal suturing is performed. In this study, we did not employ the hand-sewn technique during the creation of the gastro-jejunal anastomosis; however, we used intracorporeal suturing to reinforce the jenunostomy and the staple line during the sleeve procedure, and for closing the opening of the gastro-jejunal anastomosis; in those steps we have noticed valuable benefits with the robotic ergonomicity. Although not attempted in this study, we think that is possible to create totally both jejunal and gastro-jejunal anastomoses with the hand-sewn technique, and major benefits could be observed, such as those previously reported (6,29,30). When the robot is used, we believe that major benefits can be observed with ’more complex’ procedures, such as bariatric revisions; nevertheless, our recommendation is to use the robot in routine surgery (as presented in this paper) in order to gain the experience to perform ’more complex’ operations successfully. Some limitations may be noticeable early in one’s robotic experience, such as the time required for trocar placement and docking, and the size of the device, which could limit movement through the operating room; however, the time can be compensated for as experience progresses. The issue of moving the robot cart in a small operating room can be resolved by simply rotating the patient’s bed toward the robot before the surgery begins. Early in one’s experience, another limitation of robotic surgery could be the lack of haptic feedback. This problem can be overcome by utilizing the weaker 5 mm instruments on the robot as compared to their stronger 8 mm counterparts. This avoids placing excessive pressure on the tissues while they are handled.
Conclusions RGB has a longer surgical time, longer learning curve and a higher incidence of long-term complications than RSG. Copyright © 2014 John Wiley & Sons, Ltd.
RSGs and RGBs showed similar EWL%, although longerterm follow-up is needed for both groups to further substantiate these findings. Finally, the robotic approach to gastric bypass and sleeve gastrectomy has safety profiles and short-term weight losses similar to the laparoscopic approach, as published in the literature.
Acknowledgements We are grateful to Carmen Rodriguez RN, Assistant Vice President of Perioperative Services at South Miami Hospital; Michelle Gallas PhD, Staff at our Centre for Research and Grants, and Gail R. Walker, statistician.
Conflict of interest Dr Anthony Michael Gonzalez and Dr Jorge Rafael Rabaza are both speakers and proctors for Intuitive Surgical Inc., Sunnyvale, CA, USA; Dr Radomir Kosanovic, Dr Rey Jesús Romero, Dr Charan Donkor and Dr Armando Sarasua have no conflicts of interest or financial ties to disclose.
Funding No specific funding.
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