PATIENTS AND METHODS: A prospective, randomized, cross-over trial was undertaken to compare
MBDB with random biopsy in patients with
Barrett's esophagus segments 3 cm or more in length without macroscopic evidence of dysplasia or
cancer. Dysplasia was graded as: indefinite for dysplasia, low-grade dysplasia, high-grade dysplasia, or
carcinoma, and was reported in a blinded fashion.
RESULTS: Fifty-seven patients were recruited, 44 of whom were male. A total of 1,269 biopsies were taken (MBDB-651, random biopsie-618). Analysis of the results by per-biopsy protocol showed that the
MBDB technique diagnosed significantly more specialized intestinal
metaplasia (75 %) compared to the random biopsy technique (68 %; P = 0.032). The sensitivity and specificity rates of
MBDB for diagnosing specialized intestinal
metaplasia were 91 % (95 % CI, 88 - 93 %) and 43 % (95 % CI, 36 - 51 %), respectively. The sensitivity and specificity rates of
MBDB for diagnosing dysplasia or
carcinoma were 49 % (95 % CI, 38 - 61 %) and 85 % (95 % CI, 82 - 88 %), respectively. There were no significant differences in the diagnosis of dysplasia and
carcinoma -
MBDB 12 %, random biopsy 10 %. The
methylene blue staining pattern appeared to have an influence on the detection of specialized intestinal
metaplasia and dysplasia/
carcinoma. Dark blue staining was associated with increased detection of specialized intestinal
metaplasia (P < 0.0001), and heterogeneous staining (P = 0.137) or no staining (P = 0.005) were associated with dysplasia and/or
carcinoma detection. The
MBDB technique prolonged the endoscopy examination by an average of 6 min.
CONCLUSION: The diagnostic accuracy of the
MBDB technique was superior to that of the random biopsy technique for identifying specialized intestinal
metaplasia, but not dysplasia or
carcinoma. The intensity of
methylene blue staining has an influence on the detection of specialized intestinal
metaplasia and dysplasia or
carcinoma, which may help in targeting the biopsies. Although
MBDB prolongs the endoscopy procedure slightly, it is a safe and well-tolerated procedure. Further clinical studies on the
MBDB technique exclusively in endoscopically normal dysplastic
Barrett's esophagus are needed.