Analysis Of The Clinical,pathological And Endoscopic Features Of Sessile Serrated Adenoma/polyp And Analysis Of The Endoscopic Treatment

BackgroundColorectal cancer(CRC)is one of the most common malignant tumors of digestive tract.Sessile serrated adenoma/polyp(SSA/P)is a kind of serrated lesion with high malignant potential.It can develop CRC via the serrated neoplasia pathways.Its progress to CRC will be much earlier while SSA/P with dysplasia.There is growing evidence that colon cancer on the right may have developed from undetected SSA/P.SSA/P is mostly located on the proximal colon,generally>5 mm,its surface is mostly covered with mucus cap,so some scholars suggested that mucus cap may be one of the strongest characteristics to distinguish SSA/P.Later,other scholars found that the combination of vascular thickening and covered mucus cap was the only significant predictor of SSA/P.However,SSA/P(<5mm)on proximal colon is difficult to distinguish from hyperplastic polyp(HP)under endoscopy and may be misdiagnosed as HP.Even if the diameter of SSA/P is 10mm or smaller.there may develop cell dysplasia or carcinogenesis,so the consequences of misdiagnosis are very serious.At present,there is no consensus on whether SSA/P needs to be removed and what kind of endoscopic resection methods should be adopted.Different countries have different guidelines and recommendations.However,there are still few studies on the endoscopic and pathological characteristics of SSA/P in China,and the attention and diagnostic rate of SSA/P need to be improved.Based on this,the first part of this study analyzed the clinical,endoscopic and pathological features of SSA/P and TSA,with or without dysplasia of SSA/P and HP,covered with mucus cap,retrospectively and summarized the differential features of SSA/P under the endoscopy.The second part discusses the related factors of different endoscopic treatment methods on the efficacy of SSA/P.Chapter 1 Analysis of clinical,pathological and endoscopic features of sessile serrated adenoma/polypObjectiveTo analyze the clinical,endoscopic and pathological features of SSA/P with or without cell dysplasia in SSA/P with HP,covered with mucus cap as well as SSA/P and TSA,and to explore the endoscopic features of SSA/P under endoscopy and the related factors affecting SSA/P developing dysplasia or carcinogenesis.MethodsThe clinical data of patients with SSA/P,TSA and HP diagnosed in XX Hospital from January 2014 to January 2019 were collected and the endoscopic features and pathological features were collected as well.The endoscopic characteristics of SSA/P,TSA and HP with mucus cap were analyzed.Univariate and multivariate Logistic regression analysis were used to identify the risk factors of SSA/P.developing cell dysplasia.ResultsA total of 64 patients with SSA/P,7 patients with TSA and 7 patients with HP covered with mucus cap were included in this study.In 64 patients with SSA/P,the ratio of male to female was 2.2:1,and the average size of the lesion was 12.87±11.86mm.There were 31 cases(48.4%)located on the proximal colon and 23 cases(35.9%)located on the ascending colon.75%(48/64)of SSA/Ps were covered with mucus caps,34 cases(53.1%)were thickened,and the main morphology was type 0-Ⅱa,accounting for 51.6%(33/64).The average size of SSA/P glandular duct opening was 117.8±28.53μm,and that of normal intestinal mucosa was 44.48±9.95μm(P<0.0001).Univariate analysis showed that the proportion of superficial phenotypic lesions(0-Ⅱ a,0-Ⅱa+Ⅱc)in SSA/P was higher than that in TSA(P<0.05).Compared with HP with mucus cap,the lesion with diameter>10mm and thickening vascular on the lesion surface suggested that the lesion covered with mucus cap might be SSA/P(P<0.05).Sex,lesion size and morphology may be related to the occurrence of cell dysplasia or carcinogenesis in SSA/P.Female,lesion diameter>10mm and SSA/P with morphology of LST type may indicate that cell dysplasia or carcinogenesis is more likely to occur(P<0.05).Multivariate Logistic regression showed sex(OR=5.422,95%CI 1.265-23.243,P=0.023)as well as the lesion size(OR=1.110,95%CI 1.031-1.196,)P ≤0.006)was the independent risk factor of cell dysplasia or carcinogenesis in SSA/P.ConclusionThe size of pit of the glandular tube in SSA/P was significantly different from that in normal glandular tube.The difference of morphology may be the endoscopic features to distinguish SSA/P and TSA,and SSA/P is more likely to be superficial phenotypic lesions.Diameter>10mm and dilated vessels on the lesion surface may indicate that the lesion covered with mucus cap is SSA/P.Sex,lesion size and morphology may be related to the occurrence of cell dysplasia or carcinogenesis in SSA/P,female,lesion diameter>10mm,morphology of SSA/P may indicate that cell dysplasia or carcinogenesis is more likely to occur.Sex and lesion size are independent risk factors of cell dysplasia or carcinogenesis in SSA/P,Chapter 2 Analysis of the efficacy and related factors of endoscopic treatment of Sessile serrated adenoma/polypObjectiveTo analyze the curative effect of different endoscopic treatment methods using to remove SSA/P,and to explore the related factors affecting the complete resection of SSA/P.MethodsThe clinical data of patients with SSA/P diagnosed in XX Hospital from January 2014 to January 2019 were collected as well as the endoscopic treatment methods and postoperative pathological evaluation were recorded.Univariate and multivariate Logistic regression analysis was used to analyze the effect of different factors on the efficacy of endoscopic treatment of SSA/P.ResultsA total of 64 patients with SSA/P were included in this study.Six different resection methods were used in endoscopic treatment.Biopsy forceps were used in 9 cases(14.1%),cold snare polypectomy in 3 cases(4.7%),endoscopic polypectomy in 19 cases(29.6%)and endoscopic mucosal resection in 22 cases(34.4%).Endoscopic submucosal exfoliation(ESD)was performed in 11 cases(17.2%).In 64 cases,the complete resection rate of SSA/P was 78.1%.Nineteen patients(29.7%)were followed up,of which 1 case(1.7%)had local recurrence.the endoscopic treatment was biopsy forceps removal.Among the patients with biopsy forceps removing,66.6%(6/9)could not be completely resected,and the morphology was type 0-Ⅱa.Univariate analysis showed that the gross shape of SS A/P was 0-Ⅱa,and the resection method with biopsy forceps might indicate that SSA/P could not be completely resected(P<0.05).Multivariate Logistic regression analysis showed that gross morphology(OR=0.369,95%CI 0.178-0.768,P=0.008)was the protective factor of incomplete resection of SSA/P,and the mode of resection(OR=4.882,95%CI2.205-10.809,).P≥0.000)is an independent risk factors of incomplete resection of SSA/P.ConclusionThe complete resection rate of SSA/P was 78.1%.The morphology of SSA/P is 0-Ⅱ a,the resection method of-biopsy forceps may indicate that SSA/P can not be completely resected,and the morphology of 0-Ⅱs may indicate the possibility of complete resection of SSA/P.