Impact of post RFA treatment on neosquamous epithelium microstructure

Radiofrequency ablation (RFA) is effective treatment for Barrett's esophagus (BE). Product of successful RFA is neosquamous epithelium (NSE), which resembles native squamous epithelium and has lower risk for neoplastic transformation. Dilated intercellular spaces (IS) are common microscopic feature of reflux induced injury of esophagus. The aim of this study was to analyze the ultrastructure of NSE by transmission electron microscopy (TEM), depending on the post RFA treatment modalities and to asses impact of these findings on BE recurrence. Prospective observational clinical study based on TEM analysis of biopsy of specimens obtained from patients in whom CE of BE was achieved minimum 6 months after the last RFA session. In each patient biopsies were taken from NSE and proximal esophagus. Two groups of patients were defined according to the post RFA treatment: proton pump inhibitors (PPI's) or laparoscopic Nissen fundoplication (LNF). Comparative analysis of IS length was made between two groups. Endoscopic surveillance with biopsies was conducted for 5 years. Overall 22 patients with CE of BE after RFA underwent complete study protocol, out of whom in 10 LNF was performed, while 12 were treated with PPI's. The mean values of IS length in the proximal esophagus and NSE in LNF group were 0.378 ± 0.116 µm and 0.878 ± 0.354, while in PPI's group 0.724 ± 0.325 µm and 1.228 ± 0.226 µm, respectively. Mean lenghts of IS were statistically significantly higher in PPI's group both in NSE (p = 0.032) and proximal esophagus (p = 0.009). There were 5 BE recurrences after 5 years surveillance, 4 in PPI group and 1 in LNF group, without statistical significance (p = 0.084). Dilated IS are commonly presented in NSE of patients with CE of BE with RFA who are treated with PPI's. LNF provides may offer better reflux protection of NSE than PPI's and may reduce the rates of recurrence after successful RFA treatment.