Application Of Nano-carbon Labeling Assisted Rectal Cancer Surgery Under Ultrasound Endoscope Before Neoadjuvant Chemoradiotherapy

Objective: Patients with rectal cancer often undergo neoadjuvant chemoradiotherapy before surgery to obtain better prognosis and efficacy.However,after patients receive neoadjuvant chemoradiotherapy,the tumor will shrink or disappear,which makes it difficult for the surgeon to find the location and boundaries of the tumor accurately during surgery,and makes it difficult to determine the extent of surgical resection.This study explored whether carbon nano-labeling under ultrasound endoscope before neoadjuvant radiotherapy for rectal cancer could reduce the operation time,surgical trauma,and sought to reduce the scope of rectal surgical resection after neoadjuvant chemotherapy.Methods: From September 2017 to December 2019,the clinical data of 42 patients with rectal cancer in the same treatment group of general surgery in our hospital were analyzed retrospectively.All patients were divided into two groups: the nano carbon labeling group and the non nano carbon labeling group.The nano carbon labeling group was carried out within 1-7 days before neoadjuvant radiotherapy and chemotherapy,and 1 point was marked in each of the four quadrants 1 cm from the oral side and anal side of the lesion to the edge of the lesion respectively.Doctors used endoscopic ultrasound to locate the target location,and found the submucosa,injected 1 ml sodium hyaluronate,and then injected 0.1 ml nano carbon,a total of 4 points.All patients with rectal cancer were treated with neoadjuvant radiochemotherapy simultaneously(the long-term regimen was selected for preoperative radiotherapy: three-dimensional conformal radiotherapy,dt45-50gy(1.8-2.0)gy ×(25-28)times in high-risk recurrence area and regional lymphatic drainage area of primary tumor,for a total time of about 5-6 weeks.During the radiotherapy,the chemotherapy plan was: capecitabine 825 mg/m2,twice a day,five days a week.Two weeks after the neoadjuvant radiotherapy and chemotherapy,the patients underwent follow-up surgery 8 weeks later after the operation risk and operation indications were evaluated by endoscopy and abdominal MRI.In the non nano carbon labeling group,the operation was performed according to the intraoperative condition and the position indicated by the previous endoscopic report.The two groups were compared: general information(gender,age),preoperative condition(whether there was allergy to nano carbon,serious basic diseases and contraindications to operation),tumor characteristics(distance from tumor to anus,TNM stage),intraoperative condition(whether there was tumor invasion in continuous pathological sampling from the edge of specimen to the nano carbon mark,length of removed intestine,intraoperative bleeding volume,and overall situation The operation time,average number of lymph nodes obtained,postoperative recovery(including related complications)and related factors were analyzed.Results: There was no statistically significant difference in the general information(gender,age),preoperative status(with or without serious underlying diseases and contraindications to surgery),tumor characteristics(distance from tumor to anus,TNM stage)between the two groups(P> 0.05).The operation time of the labeled group(119.38 ± 9.68 min)was significantly shorter than that of the unlabeled group(130.43 ± 16.49 min)(P < 0.05);the bleeding volume of the nano-carbon labeling group(116.00 ± 13.90 ml)was smaller than that of the non-nano-carbon labeling group(123.67 ± 19.92 ml),but there was no obvious statistical significance(p> 0.05).The length of the excised intestine in the nano-carbon-labeled group was 17.67 ± 1.88 cm,and the length of the excised specimen in the non-nano-carbon-labeled group was 18.57 ± 2.32 cm.There was no statistically significant difference in the length of the excised intestine between the two groups(p> 0.05);The average number of lymph nodes obtained in the group was 13.48 ± 2.16,and the average number of lymph nodes obtained in the unlabeled group was 11.00 ± 2.12.The number of lymph nodes obtained in the nano-carbon labeling group was significantly higher than that in the non-labeling group(p <0.05).In addition,the continuous pathological sampling from the cutting edge to the nanocarbon mark in the specimens of the nanocarbon labeling group,the positive rate of tumor cell invasion is 2/21(9.52%);patients with postoperative infection: 2 in the nano carbon labeled group and 2 in the non nano carbon labeled group;patients with postoperative anastomotic leakage: 1 in the labeled group and 1 in the non labeled group;patients with intestinal obstruction: none in the labeled group and 2 in the non labeled group.Conclusion 1.Nano carbon labeling can help surgeons to locate tumor location and boundary rapidly under laparoscopy.2.Nano carbon labeling can help the operator to narrow the scope of operation,define the location,reduce the operation time and time of surgical exploration,reduce the surgical trauma.3.Nano carbon can mark the lymph nodes in the operation area,improve the cleaning effect and efficiency,and reduce the risk of local recurrence.