[Toluidin blue in gastrointestinal endoscopy].

Area of Science:

• Gastroenterology
• Endoscopic diagnostics
• Histological staining

Context:

• Methylene blue, previously used as an endoscopic dye, is no longer marketed for this application.
• Toluidine blue is an FDA-approved topical diagnostic agent since 2007, known for selectively staining cell nuclei.
• Increased DNA synthesis in cells leads to more intensive staining by toluidine blue, highlighting malignant cells and areas of repair.

Purpose:

• To evaluate the effectiveness and safety of toluidine blue in various gastrointestinal endoscopic applications.
• To assess toluidine blue as a potential substitute for methylene blue in chromoendoscopy and lesion demarcation.
• To investigate the utility of toluidine blue for submucosal injection in endoscopic resection procedures.

Summary:

• This study reports on 364 consecutive endoscopic applications of toluidine blue.
• Toluidine blue was used for standard chromoendoscopy (e.g., Barrett's esophagus) and, notably, for submucosal injection in flat adenomas before endoscopic mucosal resection or dissection.
• The dye effectively demarcated lesions, similar to methylene blue, and no local or systemic adverse reactions were observed.

Impact:

• Toluidine blue demonstrates efficacy comparable to methylene blue for lesion demarcation in gastrointestinal endoscopy.
• Its use in submucosal injections aids in precisely defining lesion margins for resection, potentially improving procedural outcomes.
• The absence of adverse reactions suggests a favorable safety profile for toluidine blue in endoscopic procedures.