| Objective:To explore the actual clinical significance of carbon nanoparticles suspension injection(CNSI)in the tracking and retrieval of colorectal cancer(CRC)patients,and to discuss whether black-stained lymph nodes beyond the scope of D3 lymph node dissection need to be dissected,and the appropriate injection time of CNSI.Methods:A retrospective analysis was performed on the case data of 115patients diagnosed with colorectal cancer who met the research criteria in the Department of Geriatrics and Colorectal Surgery of Xiangya Hospital,Central South University from January 2021 to September 2021.All patients were divided into two groups,of which 80 were in the CNSI group and 35 in the control group.The patients in the CNSI group were injected with CNSI under the endoscope into the submucosa of the surrounding tissue before surgery.The LNs of surgical specimens from all cases were retrieved and grouped by researchers before being sent to the pathology department for examination.Finally,the LNs data between the two groups were statistically analyzed after removing confounding factors by multiple regression.Results:There was no statistical difference in general baseline data between the two groups(P>0.05).After adjusting for the influence of confounding factors by multiple regression,the number of total lymph nodes,total positive lymph nodes,total micro lymph nodes(maximum diameter≤5mm),total micro positive lymph nodes,and the third,second,and first station lymph nodes in the CNSI group were higher than control group(b=19.07,2.21,22.09,1.34,2.42,10.01 and 6.04,P<0.05).There was a statistically significant difference between the black staining rates of micro lymph nodes and non-micro lymph nodes(61.39%(1690/2753)VS51.90%(696/1341),X~2=33.373,P<0.001).Although there was no statistical difference in the lymph node metastasis rate between the two groups(5.23%vs 5.70%,X~2=0.367,P=0.544),there was a statistical difference between the positive rate of black-stained lymph nodes and the positive rate of non-black-stained lymph nodes(4.33%vs 6.50%,X~2=9.567,P=0.002).The difference was mainly reflected in non-micro lymph nodes(6.47%vs 12.36%,X~2=13.761,P<0.001).The positive rate of the 1st,2nd,and 3rd station lymph nodes gradually decreased(6.94%(154/2220)vs 5.28%(87/1648)vs 2.60%(28/1078)),but the black staining rate gradually increased(55.02%(932/1694)vs 56.78%(787/1386)vs 66.82%(574/859)).In addition,the overall positive rate of black-stained lymph nodes outside the scope of D3 lymph node dissection was 2.15%(2/93),while the metastasis rate of the 216 groups was16.67%(1/6,1 of 6 patients with black-stained lymph nodes in the 216groups had metastases)and 11.76%(2/17,2 out of 17 216 lymph nodes had metastases).At the same time,The injection time(x)was divided into4 subgroups(x≤1 day,1<x≤3 days,3<x≤5days,x>5 days),x≤1 day was set as the control group,and the other groups were set as the control group.Compared with the control group,there was no statistical difference in the number of detected black-stained lymph nodes(P>0.05).Conclusion:1.Endoscopic injection of CNSI before surgery can increase the total number of detected lymph nodes and the number of positive lymph nodes in colorectal cancer,especially in micro lymph nodes,which has a better staining effect on micro lymph nodes.2.There is no significant difference in the positive rate of metastases between black-stained and non-black-stained lymph nodes in micro-lymph nodes,but the metastatic-positive rate of black-stained lymph nodes in non-micro-lymph nodes is lower than that of non-black-stained lymph nodes.3.For the black-stained lymph nodes beyond the scope of D3 lymph node dissection,it is recommended that 216 groups of lymph nodes be dissected during radical rectal resection,and the black-stained lymph nodes in other parts should be dissected as far as possible depending on the situation during the operation.4.In a short period of time(the longest injection time in this study was 39 days),the injection time of CNSI suspension injection had no significant effect on the retrieval number of black-stained lymph nodes. |
