Abstract: Objective:To investigate the application value of indocyanine green(ICG) fluorescence imaging in lymphadenectomy of laparoscopic radical gastrectomy for gastric cancer.
Methods:The retrospective cohort study was conducted. The clinicopathological data of 702 patients with primary gastric cancer who underwent laparoscopic radical gastrectomy and D2 lymphadenectomy in the Fujian Medical University Union Hospital between April and December 2017 were collected. There were 517 males and 185 females, aged from 22 to 91 years, with an average age of 61 years. Of the 702 patients, 39 using ICG fluorescence imaging in the surgery and 663 not using ICG fluorescence imaging were allocated into ICG group and nonICG group, respectively. Observation indicators: (1) surgical situations and postoperative recovery; (2) postoperative complications; (3) average number of lymph node dissected and positive lymph nodes; (4) followup situations. The number of lymph node dissected in the first station (No.1-7 group) and second station (No.8-12 group) were analyzed respectively. Followup using outpatient examination and telephone interview was performed to detect complications of patients up to June 2018. Measurement data with normal distribution were represented as Mean±SD, comparison between groups was analyzed using the t test. Measurement data with skewed distribution were described as M (range), comparison between groups was analyzed using the MannWhitney U test. Count data were represented as absolute number or percentage, comparison between groups was analyzed using the chisquare test. Comparisons of ordinal data were analyzed by the MannWhitney U test.
Results:(1) Surgical situations and postoperative recovery: 702 patients underwent successfully laparoscopic radical gastrectomy and D2 lymphadenectomy, without injuries of important vessels and adjacent organs, without combined multiple organs resection or conversion to open surgery. Of 39 patients in the ICG group, cases undergoing total radical gastrectomy, distal subtotal gastrectomy and proximal subtotal gastrectomy, cases with RouxenY esophagojejunostomy, Billroth Ⅰ anastomosis, Billroth Ⅱ anastomosis, RouxenY gastrojejunostomy and esophagogastric anastomosis, operation time, volume of intraoperative blood loss, time for outofbed activities, time to initial anal exsufflation, time to first fluid diet intake and duration of postoperative hospital stay were 21, 16, 2, 21, 3, 13, 2, 0, (173±28)minutes, 40 mL(range, 5-200 mL), (2.1±0.6)days, (3.5±1.4)days, (4.8±1.3)days, (8.6±3.6) days. The above indexes were 363, 299, 1, 363, 27, 267, 1, 5, (174±41)minutes, 50 mL(range, 0-1 750 mL), (2.2±0.8)days, (3.4±1.1)days, (4.6±1.5)days, (9.4±5.0)days in the nonICG group. There were statistically significant differences in the surgical type and digestive reconstruction method (x²=9.550, 11.388, P<0.05) and no statistically significant difference in the operation time, volume of intraoperative blood loss, time for outofbed activities, time to initial anal exsufflation, time to first fluid diet intake and duration of postoperative hospital stay (t=0.221, Z=-0.651, t=0.492,-0.826,-0.842, 0.995, P>0.05). (2) Postoperative complications: 92 out of the 702 patients had postoperative complications, without death of complications. The incidence of complication was 15.38%(6/39) and 12.97%(86/663) in the ICG group and nonICG group, with no statistically significant difference between the two groups (x²=0.188, P>0.05). Six patients with complications (1 of ClavienDindo Ⅳ, 2 of ClavienDindo Ⅲa, 3 of ClavienDindo Ⅰ) in the ICG group and 86 (6 of ClavienDindo Ⅳ, 16 of ClavienDindo Ⅲ, 61 of ClavienDindo Ⅱ, 3 of ClavienDindo Ⅰ) in the nonICG group were cured after symptomatic treatment. (3) Average number of lymph node dissected and positive lymph nodes: the average number of lymph node dissected and positive lymph nodes was 37 (range, 3-112) and 1 (range, 0-68) of 702 patients, 38 (range, 24-70) and 2 (range, 0-42) in the ICG group, 37 (range, 3-112) and 1 (range, 0-68) in the nonICG group, with no statistically significant difference between the two groups (Z=-1.454,-0.514, P>0.05). Stratified analysis: the average number of No.1-7 group lymph nodes dissected and positive lymph nodes was 34 (range, 16-67) and 2 (0-38) in the ICG group, 33 (range, 3-91) and 1 (range, 0-56) in the nonICG group. The average number of No.8-12 group lymph nodes dissected and positive lymph nodes was 11 (range, 4-22) and 0 (range, 0-13) in the ICG group, 9 (range, 0-31) and 0 (range, 0-25) in the nonICG group. There was a statistically significant difference in the average number of No.8-12 group lymph nodes dissected between the two groups (Z=-1.984, P<0.05). There was no statistically significant difference in the average number of No.1-7 group lymph nodes dissected, positive No.1-7 group lymph nodes and the average number of positive No.8-12 group lymph nodes between the two groups (Z=-1.302,-0.463,-0.758, P>0.05). (4) Followup situations: 702 patients were followed up for 6-14 months, with a median time of 10 months. There was no readmission caused by postoperative complications in the two groups.
Conclusion:ICG fluorescence imaging in lymphadenectomy of laparoscopic radical gastrectomy for gastric cancer is beneficial to dissection of perigastric lymph nodes and increase number of lymph nodes dissected, but cannot increase operation time and incidence of postoperative complications.