Background and study aim: Chromoendoscopy using indigo carmine staining significantly increased the detection
rate for adenomas, flat lesions, and serrated lesions, this study aimto evaluate the role of routine chromoendoscopy
using indigocarmine dye in early detection of rectosigmoid lesions.
Methods: Eighty five patients were presenting to Endoscopy Unit, Internal Medicine Department; Sohag University
forcolonoscopic examination, aged ≥40 years, all the patients were subjected to screening about rectosigmoid lesions
by conventional endoscopy thenchromoendoscopy using indigocarminedye .
Results: A total number of 85 patients were included, 52 males (61.2%), 33 females (38.8%) and their ages ranged
from 40 to 74 years with a mean of 56.54 years ± 9.21. The diagnosis after conventional colonoscopy was normal in
43 patients (50.6%) , 17 patients (20%) had hyperplastic polyps, 7 patients (8.2%) had carcinomas, 7 patients ( 8.2%)
had non- specific colitis,4 patients (4.7%) had angiodysplasia ,4 patients (4.7%) had diverticulae ,2 patients (2.4%)
had adenomatous polyps and 1 patient (1.2) had a benign rectal ulcer. Flat elevated lesions were 72 lesions (55%), flat
lesions were 57 lesions (43.5%) and lastly depressed lesions were only 2 lesions (1.5%). Histopathological
examination after chromoendoscopy were 52 lesions revealed inflammatory conditions (39.7%), 32 lesions were
hyperplastic in nature (24.4%), 4 lesions were indefinite for hyperplasia (3.1%), 23 lesions show dysplastic features
(17.5%) and 20 lesions (15.3%) show normal histopathological examination. Total conventional colonoscopy time
was 31.13±9.4,the added time by chromoendoscopy technique was 14.21±3.7 minutes and time of application of the
dye was 176.82±51.4 seconds. The chromoendoscopy is more sensitive than the conventional endoscopy because
number of false negative cases much less in the new method about 50% less than conventional method, screening test
of chromoendoscopy is about excellent sensitivity 100% and excellent specificity 100% but less sensitivity in
conventional 65%only.
Conclusion: Routine chromoendoscopy using indigocarmine is more sensitive than conventional as screening test. It
is a valuable technique in demonstrating dysplastic and inflammatory rectosigmoid lesions.
Keywords: chromoendoscopy, evaluation, screening tests, histopathological, validity