Polyp detection in the cecum and ascending colon by dye based chromoendoscopy - Is its routine use justified?

INTRODUCTION

colonoscopy is the best method for detecting polyps, with a reduction in colorectal cancer mortality of 29% and reaching 47% for distal tumors. However, it fails to demonstrate a significant reduction in proximal colon cancer mortality, and is the most common segment with interval neoplasm. The present study aimed to evaluate the impact on detection of polyps of a second sequential evaluation of cecum and ascending colon, with or without the use of indigo carmine chromoendoscopy.

METHODS

prospective, non-randomized clinical trial. Patients were divided into two groups. The first (G1) underwent a routine colonoscopy, followed by a second endoscopy assessment of ascending colon and cecum. The second group (G2) underwent a routine colonoscopy, followed by a second assessment of the ascending colon and cecum with indigo carmine chromoendoscopy.

RESULTS

In total, 203 patients were analyzed, 101 in the G1 and 102 in the G2. Newer polyps were identified in both groups after the second assessment with a significantly higher number of polyps detected in the patients in the G2 (p=0.0001). The number of patients who had at least one polyp in the two endoscopic assessments was significantly higher in the G2 (53 or 52% vs 27 or 26.7%, p=0.0002). In the second endoscopic assessment, the number of polyps found was also significantly higher in the G2 (50 or 76.9%) compared to the G1 (15 or 23.1%), p<0.0001.

CONCLUSIONS

the second assessment with dye-based chromoendoscopy increases the detection of polyps in the ascending colon and cecum.

WHICH LESIONS ARE AT HIGHER RISK OF DEVELOPING COLORECTAL CARCINOMAS: SUPERFICIALLY ELEVATED SERRATED LESIONS OR DEPRESSED LESIONS?

BACKGROUND

There are lesions that are still being missed in colonoscopy. Many of those could be superficially elevated serrated lesions or depressed ones.

AIMS

The aim of this study was to compare the histopathological characteristics of these lesions and their risks for submucosal carcinoma.

METHODS

This is a retrospective, cross-sectional, and observational study comparing 217 superficially elevated serrated lesions larger than 5 mm resected by colonoscopies (G1) with 558 depressed lesions (G2).

RESULTS

In G1, 217 lesions were found in 12,653 (1.7%) colonoscopies; in G2, 558 lesions were found in 36,174 (1.5%) colonoscopies. In G1, 63.4% were women and in G2, there was no gender predominance. The average size of G1 was 16.2 mm and G2 was 9.2 mm (p<0.001). G1 predominated on the proximal colon and G2 on the distal and rectum (p<0.001). In G1, there were 214 (98.6%) low-grade intramucosal neoplasia and 3 (1.4%) high-grade intramucosal neoplasia. Excluding 126 hyperplastic polyps and considering 91 sessile serrated adenomas in G1, we observed 88 (96.7%) low-grade intramucosal neoplasia and 3 (3.3%) high-grade intramucosal neoplasia; in G2, we observed 417 (74.7%) low-grade intramucosal neoplasia, 113 (20.3%) high-grade intramucosal neoplasia, and 28 (5.0%) submucosal adenocarcinomas (p<0.001).

CONCLUSION

Depressed lesions significantly had more high-grade intramucosal neoplasia and more invasive carcinomas in the submucosal layer than superficially elevated serrated lesions and more than superficially elevated sessile serrated adenomas.