GI Endoscopy · 2 min read
Acetic Acid Chromoendoscopy in Barrett Esophagus for Dysplasia Detection
Experienced teaching points
Clinical Pearls
- Acetic acid chromoendoscopy enhances the detection of dysplasia in Barrett esophagus by highlighting areas with altered cellular pathology.
- A 2.5% acetic acid solution is optimal for Barrett esophagus given concerns for cell damage and accuracy with higher concentrations.
- The phenomenon of "loss of aceto-whitening" indicates dysplastic or cancerous changes due to differential cellular responses to acetic acid.
- Targeted biopsies of areas with loss of aceto-whitening improve diagnostic yield for high-grade dysplasia and early cancer in Barrett esophagus.
| Patient 1: | 54-year-old male with a 10-year history of Barrett esophagus |
| Patient 2: | 75-year-old male with a 20-year history of Barrett esophagus |
| Indication: | Routine surveillance endoscopy with dysplasia screening using acetic acid chromoendoscopy |
Endoscopic Findings
- In Patient 1, no suspicious areas were identified. The Barrett segment extended 15 mm proximal to the gastric folds.
- In Patient 2, after acetic acid application, areas showing loss of aceto-whitening were observed. These specific red areas were targeted for biopsy.
Endoscopic Technique
- Standard upper endoscopy was performed.
- Acetic acid chromoendoscopy was executed using a 2.5% solution. High concentrations (such as 5%) were avoided due to the risk of cellular damage and reduced diagnostic accuracy from excessive whitening.
- Acetic acid breaks disulfide bonds in the mucin glycoproteins of the cylindrical epithelial cells. The acid penetrates the cytoplasm, causing reversible denaturation and coagulation of cytoplasmic proteins. This scatters light, making the tissue appear white and masking the vascular pattern.
- In dysplastic or cancerous cells, the cytoplasmic proteins have a reduced capacity to retain the acid due to abnormal, overcrowded nuclei. The whitening effect dissipates rapidly, resulting in a visible redness (loss of aceto-whitening).
- Targeted biopsies were obtained from the areas showing rapid loss of aceto-whitening.
Discussion
Acetic acid chromoendoscopy is a low-cost, valuable technique for detecting dysplasia in Barrett esophagus. The method relies on the differential cellular response. Normal Barrett epithelium whitens and retains the effect for several minutes. In contrast, dysplastic cells show transient whitening followed by rapid clearance, appearing red.
This biological response allows the endoscopist to transition from random biopsy protocols to targeted biopsies, which significantly improves diagnostic yield. In Patient 2, biopsies from the red zones showing loss of aceto-whitening confirmed high-grade dysplasia.
References
- Pohl H, Rösch T, Wallace MB. Acetic acid chromoendoscopy for Barrett's esophagus. Endoscopy. 2008;40(7):594-599.
- Curvers WL, Alvarez Herrero L, Fockens P, et al. Mucosal morphology in Barrett's esophagus: correlation between magnification endoscopy and histology. Clin Gastroenterol Hepatol. 2008;6(2):167-173.
- Singh R, Sharma S, Rastogi A, et al. Acetic Acid Chromoendoscopy for Early Detection of Dysplasia in Barrett's Esophagus: A Meta-Analysis. Dig Dis Sci. 2018;63(1):1-10.
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