Chromoendoscopy Periprocedural Care

Updated: Nov 28, 2022
  • Author: Kondal Rao Kyanam Kabir Baig, MD; Chief Editor: Kurt E Roberts, MD  more...
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Periprocedural Care

Preprocedural Planning

Barrett esophagus and esophageal adenocarcinoma

The increasing prevalence of Barrett esophagus and its recognition as a premalignant lesion has engendered a great deal of interest in recognizing metaplastic and dysplastic changes. [31] The increasing use of endoscopic therapy for dysplasia and adenocarcinoma has given further impetus to this concept. Chromoendoscopy is considered by some as a tool for recognizing high-risk lesions within Barrett esophagus and for facilitating definitive therapy. [13] The most commonly used dye is methylene blue.

Magnification chromoendoscopy is an important adjunctive technique that enhances the sensitivity and specificity. [32] Evaluating lesions in the absence of biopsies based on staining has also been shown to be useful. [33] Unfortunately, the sensitivity and specificity are wide-ranging. Randomized controlled trials have shown conflicting results and also equivalency to routine endoscopy. [34]

Esophageal squamous cancer

Lugol iodine is most commonly used to survey patients at risk for squamous cell carcinoma, including patients with tobacco abuse, alcohol abuse, or past head and neck cancer. [35] The sensitivity exceeds 90%, but the specificity is variable. [1] The dye may also be used to guide resection of early lesions.

Gastric metaplasia and cancer

Chromoendoscopy has been used to detect and demarcate dysplasia, intestinal metaplasia, or malignancy. [18, 36, 12] Methylene blue and congo red are used in a combination to differentiate abnormal gastric mucosa (which does not stain) from normal mucosa (which stains red or blue). [37] This may be of utility in high-risk groups targeted for intensive surveillance. [38]

There has been some evidence to suggest that Helicobacter pylori detection in the stomach is better with phenol red chromoendoscopy, though this concept has not been evaluated in clinical trials. [39, 40] Phenol red staining is being studied in assessing the functional recovery of gastric mucosa after H pylori eradication therapy. [41]

Colorectal adenoma

There have been many randomized trials for enhanced adenoma detection with chromoendoscopy using indigo carmine staining. [22, 42, 43] Pohl et al conducted a large randomized controlled trial comparing standard endoscopy with pancolonic chromoendoscopy and showed that chromoendoscopy significantly increased the detection rate for adenomas, flat lesions, and serrated lesions. There was an increase in the mean withdrawal time. [22] Other trials have shown mixed results. [44]

There may be a advantage to chromoendoscopy in detecting flat lesions. [45]  An increased cancer detection rate or survival rate has not been demonstrated. Chromoendoscopy is currently not of significant utility in screening or surveillance colonoscopy.

Colorectal cancer

Chromoendoscopy also has a limited and experimental role in endoscopically assessing the depth of known colorectal cancer. [24]

Inflammatory bowel disease

The difficulty in identifying dysplasia and carcinoma in chronic ulcerative colitis (UC) has led to the evaluation of chromoendoscopy in this particular high-risk situation. Many trials have shown that dysplasia detection is improved significantly and reproducibly. [30, 46, 47, 48, 49] The accumulation of evidence may have an impact on chronic UC surveillance guidelines. [50] Evidence with regard to carcinoma detection in this setting is equivocal. [51]


Patient Preparation

The usual preparation prior to upper endoscopy or colonoscopy and sedation administration is undertaken in the standard manner. Thereafter, specialized preparation of mucosa is carried out in accordance with the endoscopic procedure to be done, the dye or stain to be used, the suspected lesion, and the planned therapy for that lesion.