Carbon nanoparticles-guided margin identification and lymphadenectomy in laparoscopic distal gastrectomy for gastric...

Accurate tumor localization and thorough lymphadenectomy remain challenges in laparoscopic distal gastrectomy for gastric cancer. While indocyanine green (ICG) fluorescence imaging is effective, it requires near-infrared equipment, limiting its use in primary medical institutions. This study aimed to evaluate the application of a carbon nanoparticle suspension (CNS) as an alternative tracer for margin identification and lymphadenectomy.

In this retrospective study, 545 patients undergoing laparoscopic distal gastrectomy were categorized into CNS, ICG, or control groups. Propensity score matching (PSM) at a 1:1 ratio was performed. The primary endpoint was the positive rate of the initial proximal margin (PM). Secondary endpoints included the length of margins, the number of harvested lymph nodes, surgical outcomes, and prognosis.

After PSM, 133 pairs (CNS vs. control) and 127 pairs (CNS vs. ICG) were analyzed. Compared to the control group, the CNS group had a significantly lower initial positive proximal margin rate (0.8% vs. 6.0%; P = 0.039), more harvested lymph nodes (38 vs. 32; P < 0.001), less variability in PM length (P = 0.048) and shorter operation time (P = 0.008). The CNS group exhibited a smaller gastric wall diffusion range (3.3 cm vs. 5.0 cm; P < 0.001) than the ICG group. Three-year overall survival and disease-free survival were comparable between the CNS and control groups.

CNS serves as a practical auxiliary tool for margin identification and lymphadenectomy in conventional laparoscopic distal gastrectomy. Although CNS provides less precise boundary guidance than ICG, it remains a viable alternative in hospitals lacking fluorescence imaging equipment.