Effect of visceral obesity on outcomes of fluorescence-guided lymphadenectomy during laparoscopic gastrectomy for gastric cancer: Post hoc analysis of a randomized phase 3 trial

Objective: To explore the impact of visceral fat area (VFA) on the short- and long-term efficacy of indocyanine green (ICG)-guided D2 lymphadenectomy for gastric cancer (GC).

Methods: A post hoc analysis was performed in patients who participated in a phase 3 randomized clinical trial of ICG-guided laparoscopic radical gastrectomy vs. conventional laparoscopic radical gastrectomy from November 2018 to July 2019. The VFA was calculated based on preoperative computed tomography images. Short-term efficacy included the quality of lymph node (LN) dissection and surgical outcomes, while long-term efficacy included overall survival (OS) and recurrence-free survival (RFS).

Results: This study included 126 patients each in the ICG (high-VFA, n=43) and non-ICG groups (high-VFA, n=38). Compared with the non-ICG group, the ICG group had significantly more retrieved LNs (low-VFA: 50.1 vs. 43.9, P=0.001; high-VFA: 49.6 vs. 37.5, P<0.001) and a significantly lower LN noncompliance rate (low-VFA: 32.5% vs. 50.0%, P=0.020; high-VFA: 32.6% vs. 73.7%, P<0.001), regardless of the VFA. The ICG group had a shorter postoperative hospital stay and fewer intra-abdominal infections than the ICG group in the high-VFA patients (P=0.025 and P=0.020, respectively) but not in the low-VFA patients. Regardless of the VFA, the 3-year OS (RFS) was better in the ICG group than in the non-ICG group [low-VFA: 83.1% (76.9%) vs. 73.9% (67.0%); high-VFA: 90.7% (90.7%) vs. 73.7% (73.5%); P for interaction =0.474 (0.547)].

Conclusions: The short- and long-term efficacies of ICG tracing were not influenced by visceral obesity.