Analysis of safety and efficacy of laparoscopic radical gastrectomy combined with or without indocyanine green tracer fluorescence technique in treatment of gastric cancer: a retrospective cohort study

Background: An adequate resection margin and lymph node dissection are important factors for successful radical gastrectomy. The presence of near-infrared camera imaging with indocyanine green (ICG) gives new insight into radical gastrectomy. Laparoscopic radical gastrectomy with ICG is still in its initial stages and requires more evidence-based medical research. The aim of the present study was to evaluate the safety and availability of lymph node dissection and precise gastrectomy for gastric cancer patients undergoing radical resection under laparoscope with ICG, in the hope of providing evidence of application of ICG tracer fluorescence technique in radical gastrectomy. Methods: A retrospective cohort study was performed with 56 patients who underwent laparoscopic radical gastrectomy. The patients were categorized into the ICG (n=18) or the non-ICG (n=38) group based on whether preoperative endoscopic mucosal ICG injection was performed. Their clinical characteristics (age, tumor size, location, TNM stage and so on) were compared as baseline data. Perioperative outcomes (blood loss, time of first intestinal exhaust, early or long-term complications and so on) were used to assess safety. The status of lymph node dissection and tumor localization were analyzed to testify efficacy. SPSS version 26.0 was used for the statistical analysis. Results: There was no difference in clinical data at baseline. From the safety point of view, there was no difference in perioperative outcomes (operative time, blood loss, time of first intestinal exhaust and so on) between the two groups (all P>0.05). From the efficacy point of view, the number of lymph nodes <5 mm (21.84 +/- 1.86 vs. 16.24 +/- 2.10, P < 0.001), the total number of lymph nodes (34.61 +/- 5.87 vs. 29.92 +/- 5.27, P = 0.004), the number of lymph nodes dissected in perigastric regions (groups 1-7, 22.89 +/- 3.64 vs. 20.29 +/- 3.00, P = 0.007), and the number of lymph nodes in extraperigastric regions (groups 8-12, 11.72 +/- 3.06 vs. 9.61 +/- 3.18, P = 0.022) were greater in ICG group compared with non-ICG group. In ICG group, the average vertical distances between the top and bottom of the fluorescent edge and neoplastic edge were 2.65 +/- 0.58 and 2.67 +/- 0.65 cm, respectively. Fluorescent edge pathology was negative. Conclusions: ICG fluorescence could be conducive to lymph node dissection and precise gastrectomy in laparoscopic radical gastrectomy.