Analysis On Missed Diagnosis Of Colorectal Polyps And Its Relevant Factors

Aims To analyze the miss rate of colorectal polyps and the relevant factors,deepen the endoscopists’ understanding of missed diagnosis and to be helpful to reduce the miss rate of colorectal polyps during colonoscopy.Methods We retrospectively analyzed the data of 443 patients via polypectomy under colonoscopy from Mar.2005 to Mar.2015.Patients’ information such as polyp shape,size(diameter),pathological types of colorectal polyps,polyp number,location and colonoscopists’ operational numbers,bowel preparation were collected.The miss rate and potential influencing factors were analyzed.Results A total of 1241 polyps were found in 464 patients.The miss rate per polyp was 17.7%and the miss rate per patient was 34.1%.There was obvious correlation between colorectal polyp miss rate and shape(P<0.01),size(P<0.01),pathological type(P<0.01),location(P<0.01).The smaller the polyp was,the easier the polyp missed.The miss rate of sessile polyps was higher than the pedunculated polyps.Compared to the adenomatous polyps,the hyperplastic and imflammatory polyps had the higher miss rate.Polyps occurred in assending colon and sigmoid colon were easier to miss than in rectum.The miss rate was significantly higher in polyps(number≥3)than solitary polyp(OR:1.832;95%CI:1.163～2.886).Junior endoscopists(who performed less than 500 colonoscopies)was the risk factor for missed diagnosis(OR:1.827;95%CI:1.121～2.976).A total 912 adenomatous polyps were found,the miss rate was 13.6%.There was obvious correlation between adenoma miss rate and shape(P<0.01),size(P<0.01),dysplasia grade(P<0.01),location(P<0.01).And the pathological types of ademoma and miss rate were not obviously correlated(P>0.05).Conclusions A certain number of polyps were missed during clinical colonoscopy examination.The more small and flat the polyp was,the higher the miss rate was.The miss rate of hyperplastic and imflammatory polyps was higher than adenomatous polyps.Such location like assending colon and sigmoid colon were more likely to miss.Among these adenomatous polyps which were easier to miss,ademomas of small size(diameter<10mm),flat,with low-grade dysplasia and occurring in assending colon or sigmoid colon were the most common.