RESUMEN
OBJECTIVE: There are no endoscopic features that distinguish intestinal metaplasia of the cardia (CIM) from the normal cardia. Biopsy specimens are therefore randomly obtained from normal-appearing mucosa with significant potential sampling errors. Enhanced magnification endoscopy involves the combined use of magnification endoscopy with acetic acid instillation. This study assessed the value of enhanced magnification endoscopy in detecting CIM. METHODS: Patients undergoing elective upper endoscopy were invited to participate in the study. Patients were included if the squamocolumnar junction and the esophagogastric junction were judged to be at the same level. Enhanced magnification endoscopy was performed with 3% acetic acid instillation. Standard endoscopy was followed by magnification endoscopy and repeated after acetic acid spraying. Surface patterns were characterized before and after acetic acid spraying. The observed surface patterns were compared with histological results obtained from a single targeted biopsy specimen of each pattern. RESULTS: The overall prevalence of CIM was 34.8% (86/247 patients). After excluding 52 patients because of endoscopic evidence of Barrett's esophagus, 195 patients were eligible for participation in the study. In the study group, CIM was detected in 86 patients (44.1%) in targeted biopsy samples. No dysplasia was identified. Enhanced magnification endoscopy detected four different patterns of the mucosal surface: I) round pits, II) reticular, III) villous, and IV) ridged. The yields of detection of intestinal metaplasia according to endoscopic patterns were I) 0%, II) 5.3% (odds ratio = 0.05), III) 57.7% (odds ratio = 7.5, p = 0.0001), and IV) 95.8% (odds ratio = 42.8, p = 0.0001). CONCLUSIONS: CIM is more common than previously reported. Enhanced magnification endoscopy identifies two characteristic endoscopic patterns, villous (pattern III) and ridged (pattern IV), with outstanding clarity and resolution that correlate with histological identification of CIM with a single targeted biopsy sample. Enhanced magnification endoscopy will permit longitudinal studies of an entity that can be identified endoscopically.