Robotic single-site cholecystectomy

Transcription

1 J Hepatobiliary Pancreat Sci (2014) 21:18 25 DOI: /jhbp.36 TOPICS Robotic single-site cholecystectomy Philippe Morel Nicolas C. Buchs Pouya Iranmanesh François Pugin Leo Buehler Dan E. Azagury Minoa Jung Francesco Volonte Monika E. Hagen Published online: 21 October Japanese Society of Hepato-Biliary-Pancreatic Surgery Abstract Background Minimally invasive approaches for cholecystectomy are evolving in a surge for the best possible clinical outcome for the patients. As one of the most recent developments, a robotic set of instrumentation to be used with the da Vinci Si Surgical System has been developed to overcome some of the technical challenges of manual single incision laparoscopy. Methods From February 2011 to February 2013, all consecutive robotic single site cholecystectomies (RSSC) were prospectively collected in a dedicated database. Demographic, intra- and postoperative data of all patients that underwent RSSC at our institution were analyzed. Data were evaluated for the overall patient cohort as well as after stratification according to patient BMI (body mass index) and surgeon s experience. Results During the study period, 82 patients underwent robotic single site cholecystectomy at our institution. The dominating preoperative diagnosis was cholelithiasis. Mean overall operative time was 91 min. Intraoperative complications occurred in 2.4% of cases. One conversion to open surgery due to the intraoperative finding of a gallbladder carcinoma was observed and two patients needed an additional laparoscopic trocar. The rate of postoperative complications was 4.9% with a mean length of stay of 2.4 days. No significant differences were observed when comparing results between robotic novices and robotic experts. Patients with higher BMI trended towards longer surgical console and overall operative time, but resulted in similar rates of conversions and complications when compared to normal weight patients. P. Morel N. C. Buchs P. Iranmanesh F. Pugin L. Buehler D. E. Azagury M. Jung F. Volonte M. E. Hagen (*) Division of Digestive Surgery, University Hospitals Geneva, 4 Rue Gabrielle-Perret-Gentil, Geneva 1211, Switzerland monika.hagen@hcuge.ch Conclusions Robotic Single-Site cholecystectomy can be performed safely and effectively with low rates of complications and conversions in patients with differing BMI and by surgeons with varying levels of experience. Keywords Cholecystectomy Da Vinci Docking Robotic Single incision Single site Introduction Minimally invasive surgery is an ever-evolving effort striving for the best possible clinical outcome for the patient. While cholecystectomy established itself as one of the surgical procedures routinely performed laparoscopically [1], the continuous effort to further reduce invasiveness of this procedure resulted in the development of single-incision cholecystectomy [2 4]. Even though many reports demonstrate the general feasibility of single-site surgery, particularly for simpler procedures such as cholecystectomy, widespread use has not been observed so far [5, 6], particularly in challenging patients or by relatively inexperienced surgeons. This might be due to the technical challenges of manual single incision laparoscopy including loss of triangulation and the limited number of instruments that can be used at a time, resulting in compromised assistance and retraction and instrument crowding and collisions. These challenges increase the complexity of a procedure that would be considered simple using a multi-incision approach. In 2011, the da Vinci Single-Site Instrumentation and Accessories (Intuitive Surgical, Sunnyvale, CA, USA) were launched to address these limitations [7 9]. This set of instruments is designed to be used with the da Vinci Si Surgical System (Intuitive Surgical) to perform single incision laparoscopic surgery [10, 11]. These semi-rigid instruments are delivered into the abdominal cavity through curved cannulae that are inserted into a specific port in a

2 J Hepatobiliary Pancreat Sci (2014) 21: single fascial incision. Unlike the conventional robotic instruments, the Single-Site technology is non-wristed and only provides rotation. However, ergonomics are greatly improved, and this system allows for an additional port for assistance [12]. Details about the system, the technical specifications and the surgical setup have been described previously [7, 8, 12, 13]. Very early data reporting the feasibility to perform simple procedures such as cholecystectomy was confirmed by larger post-market case series [10, 11], one comparative paper to conventional single site laparoscopy [13] and a multicenter publication from Italy [14]. However, the body of scientific knowledge is relatively light at this current point in regard to the widespread application of this technology with challenging patients and robotically inexperienced surgeons. To our knowledge, this publication is to date the largest single-institution experience reporting the clinical outcomes of robotic single-site cholecystectomy using the da Vinci Surgical System with sub-analyses in regard to patient BMI and surgeon s experience. Materials and methods From February 2011 to February 2013, all the consecutive robotic Single-Site cholecystectomies were prospectively collected in a dedicated database under an Institutional Review Board approved protocol. Demographic, peri- and postoperative data with a follow-up period of 30 days from all patients undergoing robotic single-incision cholecystectomies at our institution were thus collected prospectively from the very first patient in February Initial inclusion criteria were patients between 18 and 80 years with symptomatic cholelithiasis. Exclusion criteria were acute cholecystitits, suspicion of common bile duct stones, pregnancy, severe lack of cooperation due to psychological or severe systemic illness, and presence of medical conditions contraindicating general anesthesia or standard surgical approaches. However, a minor number of patients outside the in- and exclusion criteria underwent the procedure as a deviation from the protocol, and some patients were identified as having a different final diagnosis during the procedure. The da Vinci Si Surgical System with Single-Site Technology was used for all cases as previously described [13, 15, 16]. Surgeries were performed by seven surgeons with different levels of robotic, single-incision laparoscopic and overall surgical experience. Two surgeons were very experienced, with more than 100 complex robotic gastrointestinal procedures and some single-incision laparoscopic cases previously performed. Five surgeons had less than 20 complex procedures performed robotically, and among them, three were within their first five robotic cases. All of these robotic novices had a limited experience with single incision laparoscopy. Overall patient characteristics and outcomes were summarized with descriptive statistics. Data were further stratified according to patient BMI and surgeon s experience. Pairwise comparisons for each outcome of interest were made using a two-sample t-test. A P-value of <0.05 was considered statistically significant. Results Eighty-two robotic single-incision cholecystectomies were performed in our institution between February 2011 and February Twenty-three percent of all patients were male. Mean age was 48.7 years and mean BMI was 26.3 kg/m 2. The mean American Society of Anesthesiologists (ASA) classification score was 1.7. Seventy-seven of the patients were preoperatively diagnosed cholelithiasis, of which one was discovered to be a gallbladder carcinoma during the procedure that was consequently converted to open surgery; this diagnosis was confirmed by postoperative histopathology. Two patients suffered from a biliary pancreatitis (after clearance of a common bile duct stone) and one from a gallbladder cyst. Detailed patient demographics are listed in Table 1. Port placement took a mean of 3.25 min and docking was performed in a mean of 6.6 min for all patients. The surgeons spent a mean time of 50.9 min at the surgical console with a mean overall operating room (OR) time of 91.1 min. Intraoperative complications included the addition of a laparoscopic port in two patients, one due to the need for a bipolar instrument to control a bleeding (50 ml) from the liver bed and one to improve exposure of the relevant anatomy. One case was converted to open surgery due to significant adhesions and the intra-operative suspicion of a gallbladder carcinoma, which was confirmed by histopathology after the surgery. Mean estimated blood loss was 10.6 ml, and the incision length was of 2.9 cm in mean. Postoperative complications included two patients with more than the usual amount of pain for the type of procedure performed and who required a deviation from the normal clinical pathway after single incision cholecystectomy. One of those two returned to the emergency unit due to abdominal pain and was evaluated with an abdominal ultrasound that was normal. The other patient with more than normal pain required hospitalization for 5 days. Another patient underwent an exploratory laparoscopy due to compromised clinical status 48 h after the robotic cholecystectomy, and a superficial iatrogenic lesion of the duodenum without perforation was found. Finally, a postoperative biliary leak

3 20 J Hepatobiliary Pancreat Sci (2014) 21:18 25 Table 1 Patient demographics, all patients and stratified by body mass index (BMI) Parameter: All patients (n = 82) Normal weight patients (n = 33) Overweight patients (n = 37) Obese patients (n = 12) P-values BMI < 25 kg/m 2 25 BMI 29.9 kg/m 2 BMI 30 kg/m 2 Age, years Mean x Standard deviation y Gender, percentage Female x Male y BMI, kg/m 2 Mean x Standard deviation y ASA classification Mean x Standard deviation y Final diagnosis, n (%) 77 Cholelithiasis (95.12) 32 Cholelithiasis (96.97) 37 Cholelithiasis (100) 8 Cholelithiasis (66.67) x 2 Biliary pancreatitis 1 Gallbladder carcinoma 2 Biliary pancreatitis y 1 Gallbladder cyst 1 Gallbladder cyst 1 Cholecystitis 1 Cholecystitis 1 Gallbladder carcinoma ASA American Society of Anesthesiologists, x comparison overweight vs normal weight, y comparison obese vs normal weight occurred in the patient with the gallbladder carcinoma that was completed by open surgery. The length of stay was 2.4 days in mean. Detailed intra- and postoperative parameters are listed in Table 2. When stratifying patients by BMI, both overweight and obese patients showed a significantly higher BMI when compared to the normal weight patients (P = 0.000). While age was comparable between the three groups of patients with normal, overweight and obese weight, the obese population had a significantly higher ASA score when compared to the normal weight patients (P = 0.000). In addition, the obese patient group had a lower rate of cholelithiasis as the pre-operative diagnosis (P = 0.026). Although port placement and docking of the robotic system was comparable for the groups, both console and overall OR time was significantly longer in overweight patients when compared to normal weight patients (P = and P = 0.010, respectively). Both parameters were also longer in the obese population when compared to normal weight patients, but the difference was not statistically significant (P = and P = 0.072, respectively). Intraoperative complications, conversions and the installation of an additional port were distributed fairly equally among the different patient populations (P = 0.953, P = 0.594, P = 0.953, P = 0.594, P = and P = 0.594, respectively). The rate of postoperative complications was comparable between the normal weight and the overweight group (P = and P = 0.894, respectively). There were no postoperative complications in the obese group. There were no differences in estimated blood loss and incision length among the three patient populations. Length of stay was comparable between patient groups (P = and P = 0.885, respectively). Details in regards to patient demographics, intraoperative and postoperative parameters of stratified groups according to BMI can be found in Tables 1 and 2. While the patients operated on by robotic novices were slightly younger and of lower BMI than the ones of robotic experts, these differences did not show statistical significance (P = and P = 0.078, respectively). Gender distribution and ASA classification was similar in the two patient groups. Robotic novices only operated on patients with cholelithiasis. All patients with biliary pancreatitis, cholecystitis, gallbladder cyst and gallbladder carcinoma were operated by a robotic expert. Detailed demographic data of patients stratified by surgeon s experience are listed in Table 3. Duration of port placement and docking was slightly but not significantly longer for the robotic novices (P = and P = 0.596, respectively). Console and overall operating room time was slightly shorter for the robotic novices (P = and 0.451, respectively). The intraoperative complication of duodenal laceration and bleeding occurred during surgeries performed by robotic novices, as well as the two additions of a laparoscopic trocar. Overall rates of both parameters showed no statistically significant difference when compared to the robotic experts (P = and

4 J Hepatobiliary Pancreat Sci (2014) 21: Table 2 Intra- and postoperative parameters, all patients and stratified by body mass index (BMI) Parameter: All patients (n = 82) Normal weight patients (n = 33) Overweight patients (n = 37) Obese patients (n = 12) P-values BMI < 25 kg/m 2 25 BMI 29.9 kg/m 2 BMI 30 kg/m 2 Port placement, min Mean x Standard deviation y Docking, min Mean x Standard deviation y Console time, min Mean x Standard deviation y Total OR Time, min Mean x Standard deviation y Intra-operative complications 2 Overall (2.44) 0 Overall (0) 1 Overall (2.70) 1 Overall (8.33) x Number, n (%) 1 Bleeding 1 Superficial 1 Bleeding y 1 Superficial laceration of duodenum laceration of duodenum Conversions, n (%) Port added, n (%) 1 conversion to laparotomy a (1.22) 2 Additional laparoscopic port (2.44) 1 conversion to laparotomy a (3.03) 0 (0) 1 Additional laparoscopic port (2.7) 0 (0) 0 (0) x 1 Additional laparoscopic port (8.33) Estimated blood loss, ml Mean x Standard deviation y Incision length, cm Mean x Standard deviation y Postoperative complications, n (%) Length of stay, days y x y 4 Overall (4.88) 3 Overall (9.09) 2 Overall (5.4) 0 (0) x 2 Unusual postoperative pain 1 Unusual postoperative pain 1 Unusual postoperative pain 1 Reoperation 1 Biliary leak 1 Reoperation a 1 Biliary leak 1 Incisional hernia Mean y Standard deviation x comparison overweight vs normal weight, y comparison obese vs normal weight a Conversion to open surgery was performed in a patient diagnosed with gallbladder carcinoma during the procedure to ensure adequate oncological resection y x P = 0.235, respectively). The conversion to open surgery due to a gallbladder carcinoma occurred during the surgery of a robotic expert. Estimated blood loss and incision length was comparable between the surgeon s groups (P = 0.416). The percentage of postoperative complications was slightly higher in the robotic novice group, but the difference did not reach statistical significance (P = 0.926). Length of stay was comparable between patient groups (P = 0.409). Detailed intra- and postoperative data of patients stratified by surgeon s experience are listed in Tables 3 and 4. Discussion Robotic surgery continues to evolve, and one of its latest additions single site technology is gaining popularity

5 22 J Hepatobiliary Pancreat Sci (2014) 21:18 25 Table 3 Patient demographics, stratified by surgeon experience Parameter: Robotic experts (n = 53) Robotic novice (n = 29) P-values Age, years Mean Standard deviation Gender, percentage Female Male BMI, kg/m 2 Mean Standard deviation ASA classification Mean Standard deviation Final diagnosis, n (%) 48 Cholelithiasis (90.57) 29 Cholelithiasis (100) Biliary pancreatitis 1 Gallbladder cyst 1 Cholecystitis 1 Gallbladder carcinoma [9]. We present, at least to our knowledge, the largest patient cohort at a single institution to date. Overall, our data show that robotic Single-Site surgery is very feasible in a typical patient collection suffering from cholelithiasis. We observed a very low rate of significant intra- and postoperative complications and re-operations. This falls within the findings from previous publications of robotic Single-Site cholecystectomy since its European market launch in 2011 [10, 11, 13, 14]. Similar results were also found in a recent review of Markar et al. analyzing the available prospectively randomized trials comparing laparoscopic single-incision cholecystectomy to standard multiport laparoscopy [5]. The group concluded that the procedure is safe for the treatment of uncomplicated gallstone disease, with similar outcomes to that of multiport laparoscopy. However, another review including more underlying studies by Trastulli et al. observes a higher failure rate of laparoscopic single incision cholecystectomy with more blood loss and longer OR times than the multiport approach [6]. This emphasizes again the clinical compromises that arise due to the technical limitations of manual single incision laparoscopy that might be overcome by the robotic technology. In support of this hypothesis we observed just one conversion to open surgery in a very complex case with the intraoperative finding of severe adhesions and the clinical aspect of a gallbladder carcinoma. We decided to ensure an adequate oncological resection. Therefore, we do not see this conversion as a failure of the robotic technique, but rather a result of careful consideration to ensure the best possible oncological outcome for the patient. Moreover, we would have converted this patient from a conventional four-port laparoscopy to open surgery. This patient also contributed to the list of postoperative complications and had an overall length of stay of 50 days. In two other cases, an additional 5 mm port was added for the introduction of a bipolar forceps to control a minor bleeding (50 ml) from the liver bed and one for additional retraction. The first case needed the additional port as there was no bipolar instrument available in the initial store of robotic single site instruments. A bipolar forceps had been added in the meantime. This kind of conversion will be avoidable in the future. The addition of a 5 mm laparoscopic port was also performed to assure a safe exposure of all critical structures of the triangle of Calot. We preferred this solution over risking a more serious complication. Overall, this conversion rate to open surgery of 1.2% and a 2.4% rate of adding a single laparocopic trocar seems very attractive and is significantly lower than the reported procedure failure rate of 8.4% for manual single incision surgery reported in a recent meta-analysis [6]. These low conversions are also supported by previous publications of robotic single site cholecystectomy from a variety of sites, namely a multicenter report of 100 patients with a 2% conversion rate [17]. In addition, our prospective data collection shows a low rate of postoperative complications. Of these, two were in the category of more-than-usual postoperative pain for a patient who underwent cholecystectomy. At this point, it seems we do not have a firm explanation for this phenomenon. One possibility might lie in the remote center technology of the robotic platform in combination with the forces that are applied by the system. The remote center technology ensures that all the instruments and robotic cameras rotate around one fixed point that is marked on the

6 J Hepatobiliary Pancreat Sci (2014) 21: Table 4 Intra- and postoperative parameters, patient demographics, stratified by surgeon experience Parameter: Robotic experts (n = 53) Robotic novice (n = 29) P-values Port placement, min Mean Standard deviation Docking, min Mean Standard deviation Console time, min Mean Standard deviation Total OR Time, min Mean Standard deviation Intra-operative complications 0 Overall (0) 2 Overall (6.90) Number (Percentage) 1 Bleeding 1 Superficial laceration of duodenum Conversions, n (%) 1 conversion to laparotomy a (1.89) 0 (0) Port added, n (%) 0 (0) 2 Additional laparoscopic port (6.90) Estimated blood loss, ml Mean Standard deviation Incision length, cm Mean Standard deviation Postoperative complications, n (%) 2 Overall (3.77) 2 Overall (6.90) Unusual postoperative pain 1 Unusual postoperative pain 1 Biliary leak 1 Reoperation a Length of stay, days Mean Standard deviation a Conversion to open surgery was performed in a patient diagnosed with gallbladder carcinoma during the procedure to ensure adequate oncological resection material. This theoretically minimizes torque on the abdominal wall if docked exactly at the correct location. However, precise placement of the remote center might not always be successful, and therefore increased forces might be applied, which might cause pain after the procedure. Konstantinidis et al. reported overall low pain scores in their initial experience with robotic single-site technology, but scores went up to a6onascale from 0 to 10 in range [11]. These results support our findings that some patients might suffer from pain after this procedure. The meta-analysis by Trastulli et al. revealed no difference in early postoperative pain between multiport laparoscopic and single-port cholecystectomy, but rather a significant reduction in early postoperative pain in the single incision group when multiple ports were used as many facial incisions [6]. However, overall literature of single-incision cholecystectomy reports inconclusively in regard to postoperative pain. A direct comparison of pain between these methods is not possible at this time, and further research is needed to yield more insight on this clinical endpoint. Another observed complication was the laceration of duodenum leading to a reoperation. These kinds of injuries have previously been described in the literature during laparoscopic surgery [18]. At this point, it is difficult to explain the exact mechanism of this injury due to its unnoticed nature during the event. Therefore, it is impossible to determine whether it occurred in correlation with the use of the robotic platform. However, as described, the da Vinci Surgical System does not offer haptic feedback, and inadvertent injuries might remain unnoticed during the surgeries when occurring out of the visual field. This lack of haptic feedback seems to be a particularity of robotic surgery that can easily be overcome with experience and substituted by visual input [19]. Interestingly, this injury occurred during a

7 24 surgery by a robotic novice during our study. However, we must also comment that the majority of the surgeons grouped into the robotic novice bracket were also relatively early in their surgical careers and inexperienced with manual single-site laparoscopy. Therefore, a multiplicity of learning events occurred during their cases, and it appears difficult to pinpoint the cause of these incidents. Overall, while the patient population was slightly younger, lower in BMI and ASA classification, and composed of only cholelithiasis cases in the robotic novice group, port placement, docking, console and OR times were very similar when compared to the outcomes of robotic experts. Considering the overall very successful single-site cholecystectomies of the robotic novices emphasizes once again the technical qualities of the robotic platform that provide actual feasibility to single-incision surgery. In contrast to our data, no report can be found in the current literature reporting manual single-incision cholecystectomy performed by novices to the field. Another important factor in the currently available literature of single incision laparoscopy has been highlighted by Markar et al. during their meta-analysis: Most publications show a significant patient selection for straightforward patients, and it remains unclear if manual single-incision laparoscopy is suitable for a wide patient population [5]. While the majority of our cases were also diagnosed with cholelithiasis before surgery, the amount of data allows stratification according to the patient s BMI, which might give some insight whether robotic single-site cholecystectomy might also be feasible in more challenging patients. While port placement and docking was comparable between the groups, console and OR time trended towards a longer duration in the higher BMI patients. Still, complications and conversions as relevant indicators for procedure success were similar in patients of different BMI and therefore different surgical demands. Our overall impression of the robotic platform for Single-Site robotic surgery is that this technology enables the successful execution of single incision surgery in more challenging patients. This is also underlined by the fact that the robotic experts continue to recruit more complex cases along with accumulating experience with this technology. Still, several shortcomings of this study need to be mentioned. First and foremost, this is a single-institution study with a certain selection bias in regard to the patient population. Initial inclusion criteria were set relatively tight as we were one of the first centers worldwide to use this product during a limited launch. Although we have the subjective feeling that this technology allows single-site surgery with a higher success rate in more challenging cases than manual single-incision surgery, these data do not deliver sufficient evidence that this is actually true. However, some patients were successfully operated on that did not fall strictly within the in- and exclusion criteria. While we attempt to assess more details by stratifying by patient BMI and surgeon s experience, the groups are also prone to multiple sources of bias, as distribution is not fully comparable between these groups. In addition, this was a single arm cohort with no direct comparison to alternative surgical methods. Therefore, any comparing conclusions need to be considered carefully due to the indirectness of their nature. Finally, these data show some trends that do not reach statistical significance due to the relatively small sample sizes particularly when analyzing subgroups. Still, this is so far the largest single-institutional prospective data collection assessing this relatively novel technology, and case stratification and different surgeon experience allows some interesting hypotheses about the usefulness of robotic single-site cholecystectomy. Conclusion Our study shows that robotic Single-Site cholecystectomy with the da Vinci Si Surgical System is feasible and can be performed by surgeons with a variety of robotic, single incision and overall surgical experience successfully and safely, with a low rate of complications and conversions. Whether this technique is superior to alternative approaches, including manual single incision and multiport laparoscopic cholecystectomy, remains subject to further research of higher level of evidence. Conflict of interest Monika E. Hagen has a financial relationship with Intuitive Surgical Inc. References J Hepatobiliary Pancreat Sci (2014) 21: Gallstones and laparoscopic cholecystectomy. NIH Consens Statement. 1992;10: Vidal O, Valentini M, Ginesta C, Espert JJ, Martinez A, Benarroch G, et al. Single-incision versus standard laparoscopic cholecystectomy: comparison of surgical outcomes from a single institution. J Laparoendosc Adv Surg Tech A. 2011;21: Hagen ME, Wagner OJ, Thompson K, Jacobsen G, Spivack A, Wong B, et al. Supra-pubic single incision cholecystectomy. J Gastrointest Surg. 2010;14: Broeders IA. Randomized clinical trial of single-incision laparoscopic cholecystectomy versus minilaparoscopic cholecystectomy (Br J Surg 2010;97: ). Br J Surg. 2010;97: Markar SR, Karthikesalingam A, Thrumurthy S, Muirhead L, Kinross J, Paraskeva P. Single-incision laparoscopic surgery (SILS) vs. conventional multiport cholecystectomy: systematic review and meta-analysis. Surg Endosc. 2012;26: Trastulli S, Cirocchi R, Desiderio J, Guarino S, Santoro A, Parisi A, et al. Systematic review and meta-analysis of randomized clinical trials comparing single-incision versus conventional laparoscopic cholecystectomy. Br J Surg. 2013;100:

8 J Hepatobiliary Pancreat Sci (2014) 21: Morel P, Pugin F, Bucher P, Buchs NC, Hagen ME. Robotic single-incision laparoscopic cholecystectomy. J Robot Surg. 2012;6: Wren SM, Curet MJ. Single-port robotic cholecystectomy: results from a first human use clinical study of the new da Vinci singlesite surgical platform. Arch Surg. 2011;146: Balaphas A, Hagen ME, Buchs NC, Pugin F, Volonte F, Inan I, et al. Robotic laparoendoscopy single site surgery: a transdisciplinary review. Int J Med Robot. 2013;9: Morel P, Hagen ME, Bucher P, Buchs NC, Pugin F. Robotic single-port cholecystectomy using a new platform: initial clinical experience. J Gastrointest Surg. 2011;15: Konstantinidis KM, Hirides P, Hirides S, Chrysocheris P, Georgiou M. Cholecystectomy using a novel Single-Site((R)) robotic platform: early experience from 45 consecutive cases. Surg Endosc. 2012;26: Kroh M, El-Hayek K, Rosenblatt S, Chand B, Escobar P, Kaouk J, et al. First human surgery with a novel single-port robotic system: cholecystectomy using the da Vinci Single-Site platform. Surg Endosc. 2011;25: Spinoglio G, Lenti LM, Maglione V, Lucido FS, Priora F, Bianchi PP, et al. Single-site robotic cholecystectomy (SSRC) versus single-incision laparoscopic cholecystectomy (SILC): comparison of learning curves. First European experience. Surg Endosc. 2012;26: Pietrabissa A, Sbrana F, Morelli L, Badessi F, Pugliese L, Vinci A, et al. Overcoming the challenges of single-incision cholecystectomy with robotic single-site technology. Arch Surg. 2012; 147: Morel P, Hagen ME, Bucher P, Buchs NC, Pugin F. Robotic single-port cholecystectomy using a new platform: initial clinical experience. J Gastrointest Surg. 2011;15: Konstantinidis KM, Hirides P, Hirides S, Chrysocheris P, Georgiou M. Cholecystectomy using a novel Single-Site robotic platform: early experience from 45 consecutive cases. Surg Endosc. 2012;26: Pietrabissa A, Sbrana F, Morelli L, Badessi F, Pugliese L, Vinci A, et al. Overcoming the challenges of single-incision cholecystectomy with robotic single-site technology. Arch Surg. 2012; 147: Testini M, Piccinni G, Lissidini G, Di Venere B, Gurrado A, Poli E, et al. Management of descending duodenal injuries secondary to laparoscopic cholecystectomy. Dig Surg. 2008;25: Hagen ME, Meehan JJ, Inan I, Morel P. Visual clues act as a substitute for haptic feedback in robotic surgery. Surg Endosc. 2008;22: