MISS RATE FOR COLORECTAL POLYPS: A RETROSPECTIVE STUDY OF TANDEM VIDEO COLONOSCOPIES

Aims:

The purposes of this study are to determine the number of missed colorectal polyps and to evaluate the factors that have led to it.

Methods:

This study was performed on a succession of patients who had at least one colorectal adenoma sized more than 5 mm. The participated patients underwent tandem screening colonoscopy and EMR within the next 3 months. Bowel cleansing was performed using polyethylene glycol (Fortrans; Ipsen Pharm).

Results:

For 47 patients (12%) previously not identified 81 colorectal polyps were diagnosed (20 male and 27 female; average age 69 years). The shape of polyps did not affect the miss rate: 44 (54, 3%) were pedunculated, 37 polyps (45, 7%) were flat lesions.

Among all 387 cases, 318 primary diagnostic colonoscopy were performed in the endoscopy department of Yaroslavl Regional Cancer Hospital, in this group the number of missed polyps was 32 (10.1%), and 69 were observed at ordinary city hospitals, the number of undetected polyps – 14 (18.9%).

53 polyps in 35 patients were adenomas (9.3% of the total number of patients). In 3.1% missed advanced adenoma was identified. In one case (0.26%) of the colon cancer was diagnosed. At the initial colonoscopy in 13% of patients the quality of colon preparation was fair, and in 10% – poor. There were other pathological processes associated with colon for 12 patients (14.8%): previous surgery, diverticulosis, spasm of the colon's sphincter.

Conclusions:

Colonoscopy is a complex diagnostic method and its results are affected by many factors (quality of bowel cleansing, technique and equipment, applying additional methods of contrasting mucosal, qualification of the doctor, etc.). The number of missed polyps after colonoscopies conducted in endoscopy units of ordinary hospitals was almost twice higher than that performed in specialized department (18,9% vs. 10.1%).