ABSTRACT
Objective To study the missed diagnosis of colorectal polyps during colonoscopy and its risk factors.Methods Data of 655 patients who underwent repeated co]onoscopy in 3 months (90 days) were analyzed in three endoscopy centers in Shenzhen.Miss rates of polyps and patients were calculated.Logistic regression analysis was used to identify the suspected risk factors associated with the miss rate including gender,age,symptoms of patient and number,shape,location of polyps.Results A total of 459 polyps(20.47％,459/2 242) in 224 patients(34.20％,204/655) were missed in overall 1 783 polyps within 655 patients.The patient miss rate increased with the polyp count increasing from 1 to 4,but with no significant differences.Polyp count of more than 5 was the independent risk factor for patient miss rate during colonoscopy(OR=4.98,P=0.00).Polyps in males were easier to be missed than those in females (OR =1.76,P =0.00).Size less than 5 mm was the independent risk factor for missed diagnosis during colonoscopy(OR=2.94,P=0.00).The flat type(Yamada Ⅰ,Ⅱ) was also the independent risk factor(OR=2.72,P=0.01;OR=3.23,P=0.00 respectively).Conclusion The miss rate of polyps is related to gender,basic polyp count,the size and shape of polyp.Male with multiple polyps and polyps with flat type and small size tend to be missed.
ABSTRACT
BACKGROUND/AIMS: Colonoscopy is the most effective method to detect and remove colonic polyps and for colorectal cancer screening and prevention. However, polyps are frequently missed during colonoscopy. The aim of this study was to determine the miss rates of polyps by colonoscopy and to evaluate the factors that affect the miss rates. METHODS: Within sixty days after a first-time colonoscopy, consecutive polypectomies were performed in 317 patients who had one or more colon polyps. RESULTS: The overall miss rate for polyps was 26.6%. As the withdrawal time increased, the number of polyps detected on the first colonoscopy decreased, and the miss rate decreased significantly (respectively p=0.000, p=0.028). The withdrawal time for an expert operator was shorter than the withdrawal time for a beginner operator (p=0.001). The miss rate for a beginner operator and expert operator was not different (p=0.271) due to interference with withdrawal time. The most frequent location of a polyp was the ascending colon and the most frequent size of a polyp was < or =5 mm. CONCLUSIONS: Although colonoscopy is the gold standard for colorectal polyp detection, it is imperfect even when meticulously performed. To reduce the miss rates of polyps, it is important that a careful examination with sufficient withdrawal time is performed, the colonoscopy is complete to the cecum, and that the bowel preparation is adequate.