IRON: A retrospective international multicenter study on robotic versus laparoscopic versus open approach in gallbladder cancer

Objective: For patients with T1b gallbladder cancer or greater, an adequate lymphadenectomy should include at least 6 nodes. Studies comparing short- and long-term outcomes of the open approach with those of laparoscopy and robotic approaches are limited, with small sample sizes, and there are none comparing laparoscopic and robotic approaches. This study compared patients who underwent robotic, laparoscopic, and open resection of gallbladder cancer, evaluating short- and long-term outcomes. Methods: We conducted a multicenter retrospective study of patients with T1b gallbladder cancer or greater (excluding combined organ resection and T4) who underwent open, laparoscopic, and robotic liver resection and lymphadenectomy between January 2012 and December 2022. The 3 groups were matched in terms of patient baseline and disease characteristics based on propensity score matching, comparing robotic with open and robotic with laparoscopic groups. Results: We enrolled 575 patients from 37 institutions. After propensity score matching, the median number of harvested nodes was higher in the robotic group than in the open (7 vs 5; P = .0150) and laparoscopic groups (7 vs 4; P < .001). The Pringle maneuver time was shorter with robotic resection than with laparoscopy (38 vs 59 minutes; P = .0034), and the robotic group also had a lower conversion rate (3% vs 14%, respectively; P = .005) and less estimated blood loss than open and laparoscopic resections. The perioperative morbidity and mortality rates did not differ. The robotic and laparoscopic approaches were associated with faster functional recovery than the open group. In the multivariate analysis, the factors related to the retrieval of at least 6 nodes were the robotic approach over open (odds ratio, 5.1529) and over laparoscopy (odds ratio, 6.7289) and the center experience (≥20 minimally invasive liver resections/year) (odds ratio, 4.962). After a mean follow-up of 42.6 months, overall survival and disease-free survival were not different between groups. Conclusion: Compared with open and laparoscopic surgeries, the robotic approach for gallbladder cancer performed in a center with appropriate experience in minimally invasive surgery can provide adequate node retrieval.