Risk factors for miss rate of colorectal adenomas during conventional colonoscopy / 中华消化内镜杂志

ABSTRACT

Objective To determine risk factors for the miss rate of colorectal adenomas during colonoscopy.Methods A total of 981 patients,diagnosed as having at least one polyp in colonoscopy,received a second colonoscopy in 6 months from November 2012 to March 2016.All polyps were removed in the second colonoscopy.Bio-information of patients such as sex,age,surveillance interval and features of polyps such as number,size,shape,location,pathology,withdrawal time,bowel preparation was retrospectively analyzed.Factors associated with the miss rates in these patients were analyzed with Chisquare and was also analyzed with Logistic regression model for multiple factors.Results A total of 981 patients were selected according to the inclusion and exclusion criteria,including 604 males and 377 females.Miss rates of males and females were 38.9％ (235/604) and 27.9％ (105/377) (P＜0.01)respectively.Age ranged from 25 to 87 years with mean age being 61.0±9.7 years.Miss rates of senior patients ＜65 and ≥65 years were 31.5％(195/619) and 40.1％(145/362) respectively (P＜0.01).A total of 1 728 adenomas were found in first colonoscopy.A total of 2 267 adenomas were found in the second colonoscopy.The adenoma miss rate was 23.8％ (539/2 267).The miss rate of adenoma whose size ≤ 5 mm was 42.5％ (311/732);and that of larger size of 6 to 9 mm was 17.8％ (194/1 090);that of even larger size,i.e.,≥10 mm,was 7.6％(34/445)(P＜0.01).Miss rates of Is,Isp,Ip,LST and Ⅱ adenomas in shape were 28.4％(489/1 720),9.3％(24/235),6.6％ (12/182),9.0％(6/67) 20.5％ (8/39) respectively (P＞0.05).Location with highest adenoma miss rate were descending colon,ascending colon and transverse colon,27.8％(64/230),25.5％(120/470),25.5％ (161/632) respectively.Miss rates of high and low risk adenoma were 44.8％ (277/618) and 17.4％ (63/363) (P＜0.01).The highest adenoma miss rate of all the pathology type was tubular adenoma.The adenoma miss rate was 26.9％ (449/1 671) (P＜0.01).Miss rates of good and poor bowel preparation were 30.2％ (271/897) and 82.1％ (69/84) (P＜0.01).Miss rates of adequate and inadequate withdrawal time were 24.3％ (174/717) and 62.9％ (166/264) (P＜0.01).Conclusion Male,old-age,diameter ≤ 5 mm,poor bowel preparation and inadequate withdrawal time,high risk adenoma are the risk factors for missed adenoma.But the shape and location of adenoma are not the risk factors.