Does Chromo Endoscopy in Association with High-Resolution Video Endoscopy Improve Colorectal Adenomas Diagnosis by Colonoscopy?

Abstract

Introduction: First intent exam for colorectal (CR) adenomas diagnosis is the colonoscopy. Structure enhancement function (SEF) and chromoscopy by indigo carmine dye solution (IC) intend to increase the detection of mucosal irregularities. The aim of this multicenter, randomized, prospective study was to determine if using combination SEF and chromoscopy, it would be possible to diagnose more adenomas by colonoscopy in a group of high risk level patients. Patients and methods: All included patients had individual history of CR adenomas and\or a first -degree family history of CR cancer (except genetic disease).They were randomized to have during the same session: either two successive colonoscopies with first passage without SEF/IC (to look for abnormalities of colour which would have been able to be masked with the dye) and second passage with SEF/IC (SEF/IC group); or two successive colonoscopies without SEF/IC (control group). The histopathology of all lesions was obtain on endoscopic resection specimens or biopsy specimens. Analysis concerned number, histopathology and location of colorectal lesions. Results: 294 patients were included (mean age: 59 years). 33% had individual history only, 48% had family history only and 19% both. The rate of patients with an adenoma or more was 39% (58/147) in the SEF/IC group and 36% (53/147) in the control group (NS). The total number of adenomas found in the SEF/IC group was 111 and 86 in the control group (NS). The number of adenomas > or = 10mm was not different in the 2 groups (total =11). This study identified 13 advanced CR lesions: 11 in the SEF/IC group (2 adenocarcinomas seen during the first passage and 9 high-grade dysplasia lesions (HGD), 7 seen during the first passage) and 2 in the control group (2 HGD). 60 patients (41%) had one or more hyperplastic polyp in the SEF/IC group and 39 (27%) in the control group (p=0,01). Conclusion: There is a trend to a better detection of adenomas by combining contrast chromoscopy and magnification colonoscopy, in a high risk level population but difference is not significant. On the basis of the presented data, we can not recommend the systematic use of these techniques for detection of adenomas in high risk level patients.