The study group included 71 women and 29 men, with a mean (SD) age of 53.4 (12.9) years (range, 19-78 years) and a mean (SD) BMI of 24.4 (3.7) (range, 16.5-29.7). Of the first 100 patients who underwent single-site robotic cholecystectomy, 2 (2%) were converted to open surgery owing to unexpected chronic inflammation at the hilum of the gallbladder. One of these patients was first converted to 4-port classic laparoscopy then to open surgery. There were no deaths from any cause during the study period and no major intraoperative injury was reported. Minor intraoperative complications occurred in 12 patients (12%), including 7 ruptures of the gallbladder and 5 cases of minor bleeding from the gallbladder bed. The single-site port was sometimes difficult to put into position (mean difficulty score, 3.2, with a range between 1 [easy] and 5 [very difficult]), and a tendency to tear the internal silicone edge during this phase was reported in 15 cases (15%) by 4 of the 5 evaluating surgeons (Table 1). A minor gas leak between the cannulas and the silicone port that did not require any specific action was also noted during 7 operations (7%) by 3 surgeons. Total (SD) operative time was 71 (19) minutes (median, 70 minutes; range, 39-140 minutes). Subcomponents of this operative time included insertion of the robotic SILS device (mean [SD], 13  minutes; median, 15 minutes; range, 5-35 minutes), console cholecystectomy time (mean [SD], 32  minutes; median, 31 minutes; range, 12-80 minutes), and closure of the parietal incision (mean [SD], 17  minutes; median, 16 minutes; range, 5-47 minutes). Regarding the learning curve analysis, 5 different surgeons (1 for each center) were involved in the study. Each operated on 12 to 42 patients (median, 18 patients). To increase the homogeneity of the data, the analysis of the learning curves was limited to the first 20 patients operated on by each surgeon. The results from the mixed linear models are summarized in Table 2. Graphs plotting time as a function of experience (number of patients) are presented in Figure 2. As shown, none of the considered times (total time and each of its main components) appeared to significantly decrease with the number of patients operated on, although some shortening of the total operating time could be observed. More specifically, cumulative analysis of the console time, which represents the most important operative step, was graphically represented by an almost flat line, showing no significant reduction in the time required for the robotic dissection of the gallbladder with the increasing of each surgeon's experience. The quality of vision with the 8.5-mm 3-dimensional optics was rated slightly inferior to that provided by standard 12-mm da Vinci optics by 2 of the 5 surgeons. The ergonomy of the single-site setup in comparison with standard multiport robotic surgery was judged worse by 2 surgeons and equal by the other 3. In rating the degree of difficulty encountered during the console dissection with the da Vinci single-site cholecystectomy, in comparison with other techniques, all surgeons agreed in stating that it was more complex than standard 4-port laparoscopy but easier than single-incision laparoscopy (3 of 3 with experience with SILS). All 5 surgeons believed that single-site cholecystectomy may offer a cosmetic benefit to the patient, whereas only 2 thought the procedure is likely to lessen postoperative pain.