Efficacy of activated carbon nanoparticles suspension for lymph node tracing in colorectal cancer surgery: A systematic review and meta-analysis

This study aims to assess the efficacy of activated carbon nanoparticles suspension in detecting lymph nodes and nodal metastasis during colorectal cancer surgery. A comprehensive literature search was conducted in PubMed, Embase, the Cochrane Library, and Web of Science for studies published up to May 20, 2025. Eligible studies comparing ACNS to a blank control in patients undergoing curative resection of colorectal cancer were included. Quality assessments were performed, and a meta-analysis was conducted using Stata 18.0. Sixteen studies involving 6332 patients were included in the analysis. ACNS application significantly increased the total number of lymph nodes harvested per patient (WMD = 6.32, 95 % CI: 4.55 to 8.08, p < 0.001). It also increased the proportion of patients with ≥12 lymph nodes examined (OR = 10.050, 95 % CI: 3.596 to 28.086, p < 0.001), improved the yield of small lymph nodes (≤5 mm) (WMD = 6.19, 95 % CI: 3.17 to 9.22, p < 0.001), and enhanced the retrieval of No. 253 lymph nodes (WMD = 1.21, 95 % CI: 0.552 to 1.868, p = 0.0003). However, no significant differences were observed between groups in the number of metastatic lymph nodes (WMD = 0.24, 95 % CI: −0.23 to 0.71, p = 0.311) or the detection rate of metastatic lymph nodes (OR = 1.056, 95 % CI: 0.846 to 1.318, p = 0.631). ACNS serves as an effective lymphatic tracer, enhancing lymph node retrieval in colorectal cancer surgery. However, further researches are needed to confirm these findings.