Colonoscopic surveillance for cancer in longstanding extensive ulcerative colitis relies heavily on non-targeted mucosal biopsies.
Chromoendoscopy can aid detection of subtle mucosal abnormalities.
In this study, investigators from England assessed whether routine pancolonic indigo carmine dye spraying would improve macroscopic detection of dysplasia and reduce dependence on non-targeted biopsies.
The team evaluated 100 patients with longstanding extensive ulcerative colitis who attended for colonoscopic surveillance.
|There was increased dysplasia detection following dye spraying.|
During the patient's first examination, all visible abnormalities were biopsied. In addition, quadrantic non-targeted biopsies were taken every 10 cm.
The investigators used pancolonic indigo carmine (0.1%) during the second colonoscopic examination, and biopsied any additional abnormalities.
Median extubation times for the first and second colonoscopies were 11 and 10 minutes, respectively.
The team found that the 2904 non-targeted biopsies did not detect any dysplasia.
However, 43 mucosal abnormalities in 20 patients were detected during the first colonoscopy. Of these, 2 were dysplastic.
A further 114 abnormalities in 55 patients were detected following dye spraying. Of these, 7 were dysplastic.
The investigators identified a strong trend towards increased dysplasia detection following dye spraying.
They determined that the targeted biopsy protocol detected dysplasia in significantly more patients than the non-targeted protocol.
Dr Rutter's team concluded, "No dysplasia was detected in 2904 non-targeted biopsies".
"In comparison, a targeted biopsy protocol with pancolonic chromoendoscopy required fewer biopsies (157) yet detected 9 dysplastic lesions, 7 of which were only visible after indigo carmine application".
"Careful mucosal examination aided by pancolonic chromoendoscopy and targeted biopsies of suspicious lesions may be a more effective surveillance methodology than taking multiple non-targeted biopsies".