The Application Value Of Preoperative Endoscopic Tattooing With Carbon Nanoparticles In Laparoscopic Radical Gastrectomy

Objective:Nowadays,surgical resection still remains as the only curative therapy for gastric cancer.In the earlier times,laparoscopic gastrectomy was mainly used for early gastric cancer.With the development of minimally invasive technique,laparoscopic radical gastrectomy has been widely used in the treatment of advanced gastric cancer,and achieved a good therapeutic effect.Although some previous studies have proposed that laparoscopic gastrectomy and laparotomy has the same curative effect,and laparoscopic gastrectomy is superior to laparotomy in the aspects of lymph node dissection and digestive tract reconstruction,there has been a controversy about the efficacy of lymph node dissection in laparoscopic gastrectomy.Some scholars believe that the number of lymph node dissected in laparoscopic surgery is less than that in the laparotomy.Compared to laparotomy,laparoscopic gastrectomy has poorer tactile sense,and almost all the procedures are completed in laparoscope in totally laparoscopic gastrectomy(TLG),so it is rather difficult to locate the tumor and confirm a safe resection margin when the tumor is not infiltrated serosa layer or located in the upper part of the stomach.This study is aimed to evaluate the application value of carbon nanoparticles(CNs)in lymph node dissection and tumor localization in laparoscopic gastrectomy.Methods:A total of 75 patients who underwent laparoscopic radical gastrectomy with D2 lymph node dissection between December 2016 and November 2017 were enrolled in this study.31 out of 75 patients(21 males and 10 females)received preoperative endoscopic tattooing with carbon nanoparticles(CNs group),and the rest 44 cases(38 males and 6 females)served as the control group.The carbon nanoparticles used for lymphatic mapping as a tracer was purchased from Chongqing LUMMY Pharmaceutical Co.,China.Patients in the lymphatic mapping group received endoscopic injection of carbon nanoparticles one day before the surgery.1 mL of standard carbon nanoparticles suspension(1 ml:50 mg)was endoscopically injected into the submucosal layer at 2 points(proximal and distal site)0.5cm away from the tumor border,and all operations of lymphatic mapping technique were performed by the same sophisticated gastroenterology physician.All dissected lymph nodes were separated into several stations before they were sent for pathological analysis.Size of each lymph node was measured by using millimeter steel ruler.In the lymphatic mapping group,the distance between the tumor border and the endpoint of the stained area,vertical to the resection line,was also recorded.Statistical analysis was performed using SPSS 17.The Student's t test was used for comparisons of continuous variables when applicable.Otherwise,the Wilcoxon test was applied.Categorical variables were compared with the Yates correction or the Fisher's exact test,as appropriate.Results:The shortest interval between the endoscopic injection of carbon nanoparticles and the laparoscopic gastrectomy was 16 hours while the longest was 35 hours.None of the patients in the CNs group had endoscopy related complications such as fever,bloating,abdominal pain and hemafecia.All the patients in two groups underwent laparoscopic D2 gastrectomy,including laparoscopic assisted gastrectomy(n=61)and totally laparoscopic gastrectomy(n= 14).No intraoperative hemorrhage or postoperative complication appeared.All the resection margins were negative according to the intraoperative rapid pathological examination and postoperative routine pathological examination.A total of 1157 lymph nodes were harvested in the CNs group while 1327 lymph nodes were harvested in the control group.In the CNs group,the mean number of harvested LNs(37.32± 10.27)was greater than that of the control group(30.16±11.29),p<0.05.More LNs smaller than 5mm in diameter were harvested in the CNs group(p<0.05).And no significant difference was exhibited between the two groups in the number of metastatic LNs(p>0.05).The mean distance between tumor border and the endpoint of the stained area,vertical to the resection line was 4.0810.37cm,which was helpful in tumor localization and determining the length of resection margin in laparoscopic gastrectomy.Conclusions:Preoperative endoscopic tattooing with CNs is a safe and feasibile mathod,which can not only help the surgeons perform more effective lymph node dissection,but also make it easier to locate the tumor and achieve a safe resection margin in totally laparoscopic gastrectomy.