Preferential repair by squamous epithelium of thermal induced injury to the proximal stomach in patients undergoing ablation of Barrett's esophagus.

BACKGROUND

The presence of extensions of squamous epithelium into the proximal stomach in patients undergoing routine upper endoscopy has recently been described. The factors that may favor development of squamous epithelium within the proximal stomach remain unknown.

METHODS

Patients with Barrett's esophagus who agreed to undergo ablation of Barrett's epithelium by using multipolar electrocoagulation were included. Patients were treated with a high dose of a proton pump inhibitor. The columnar-appearing mucosa was systematically treated. Occasionally, thermal injury was inadvertently induced in the proximal stomach. On endoscopy performed 4 to 6 weeks after treatment, the presence of squamous epithelium extending into the proximal stomach was documented. The use of Lugol's stain assisted in confirming the squamous nature of the abnormal tissue, which was confirmed histologically by cytokeratin immunohistochemistry.

RESULTS

The 12 patients included in the study had a mean length of Barrett's epithelium of 3.8 +/- 0.7 cm. Patients were treated with omeprazole, mean dose 66 +/- 6.0 mg, and had a mean percent total time that the pH was less than 4 of 1.9 +/- 0.8. The mean length and width of gastric squamous extensions were 1.7 +/- 0.2 cm and 0.8 +/- 0.1 cm, respectively. None of the squamous extensions into the stomach were documented before mucosal ablation. The extensions stained positively for cytokeratin 13 and negatively for cytokeratin 8, thereby confirming their squamous nature.

CONCLUSIONS

Thermal injury to the proximal stomach in patients undergoing ablation of Barrett's epithelium and profound acid suppression results in repair by squamous epithelium. Recognition of this lesion is essential because it may lead to confusion as to the location of the esophagogastric junction in subsequent endoscopic evaluations.