The Basic Study Of Using Real-time Optical Biopsy To Evaluate Distal Resection Margin In Low Rectal Cancer

BackgroundSurgical resection is the main treatment of rectal cancer.At present,radical resection surgical procedure includs low rectal anterior resection(LAR)and transabdominal perineal resection(APR).The lower resection margin(DRM)is an important indicator to evaluate whether a tumor has undergone radical resection.If DRM is negative,LAR is performed.The latter procedure requires resection of the anus and performs permanent sigmoidostomy,which will bring obvious adverse effects on the patient's psychological and life.However,as mentioned above,the implementation of LAR must ensure that DRM is negative,so the surgeon needs to quickly determine the margin conditions during surgery.In current clinical,intra-operative frozen resection is the common menthod for rapid judgment of the surgical margin.However,intra-operative frozen section can only examine the in vitro tissue after cutting the anastomoses of the rectal,which is delayed and time consuming.If the result of the frozen section is positive,it had to cut and anastomoses the rectal twice or change to APR.Therefore,at present,there is a lack of clinical examination methods that can real-time determine the condition of the ?rectal cancer' DRM before cutting the anastomoses rectal in surgery.Optical biopsy(OB)is a new product of interdisciplinary science that based on physics theory,optical phenomena,through engineering methods,and finally applied to biology and medicine.This study focuses on confocal laser microscopy(CLE)and multiphoton imaging(MPM)optical biopsy methods.Both CLE and MPM can perform microscopic observation of living tissues at the cell level,and thus have been applied to the diagnosis and monitoring of various benign and malignant diseases.The feasibility of CLE and MPM imaging in various normal tissues and tumor tissues has been confirmed by several studies.Therefore,how to apply these two types of optical biopsy methods to clinical practice and truly solve clinical problems is the current trend of optical biopsy research.Research purposesIn this study,CLE and MPM techniques were applied to low rectal cancer surgery to diagnose DRM in vivo before cutting the anastomoses of rectal and to help surgeons choose the optimal resection plane according to each patients' particular situation.Research methodsThis study first applied CLE in the low rectal cancer surgery to in vivo,real-time detecte DRM,and finally compared CLE diagnose results with intraoperative frozen and post-operative HE staining pathological results to assess the sensitivity,specificity and accuracy;then we used MPM to diagnose DRM tissue to evaluate the feasibility of MPM in the diagnosis of distal resection margin of rectal cancer.ResultThe sensitivity,specificity,positive predictive rate,negative predictive rate,and accuracy of real-time detection of DRM in confocal laser microscopy were 85.71%,100%,94.44%,100%,91.66%respectively compared with HE staining results.On this basis,we further studied the feasibility of MPM in the real-time judgment of the distal resection margin in low rectal cancer surgery.The results of the study showed that MPM can perform high-resolution,high-resolution imaging of the subrectal margin tissue without the use of exogenous contrast agents.ConclusionIt is feasible to using real-time optical biopsy to evalutae DRM in low rectal cancer surgery and to determine the final surgical procedure.