Buried Glandular Mucosa After Radiofrequency Ablation of Dysplasia in Barrett's Esophagus

Abstract

Background: Radiofrequency ablation (RFA) is an accepted modality for endoscopic treatment of dysplastic Barrett's esophagus. Neosquamous mucosal ingrowth overlying persistent intestinal metaplasia, known as buried glandular mucosa, or “buried Barrett's,” has been observed after other endoscopic ablative techniques. However, there have been no reports of this finding in surveillance biopsies after RFA. Methods: We identified all patients treated at our center for Barrett's esophagus using the HALO ablation system. Patients were excluded if they had been treated with other ablation modalities, or if no follow-up biopsies were available. Seattle protocol biopsies were obtained of the length of treated esophagus between 6 and 12 weeks after the most recent RFA. Biopsies were interpreted by expert pathologists at our institution. Buried glandular mucosa was defined as specialized columnar epithelium beneath a layer of squamous epithelium with no communication with the surface. Follow-up was defined as the time from first RFA treatment to most recent biopsy. All patients were treated with twice daily PPI for at least 6 weeks after RFA. Results: A total of 41 patients were identified and 27 were included in the study. Fourteen patients were excluded due to a history of treatment with other ablation modalities (8) and lack of follow-up pathology (6). The median age was 61 years (interquartile range (IQR); 55, 74) and 70% were male. The median Barrett's segment length was 2 cm (IQR 0.5, 6). The cohort included 3 patients with non-dysplastic Barrett's, 5 with low-grade dysplasia (LGD), and 19 with high-grade dysplasia (HGD), 6 of whom also had intramucosal adenocarcinoma. Thirteen of these had undergone EMR prior to RFA. Three underwent circumferential ablation only, 18 underwent focal ablation only, and 6 underwent step-wise circumferential and focal RFA. The median number of treatment sessions was 2 (IQR 1, 2) and median follow-up was 6 months (IQR 5, 11). Buried glandular mucosa was reported in 4 patients (14.8%); 3 of these patients initially had HGD and one had LGD. RFA was repeated in all 4 patients. In one, buried glandular mucosa was not observed on Seattle protocol biopsies on three subsequent occasions. In the others, repeat surveillance biopsies have not yet been obtained. Conclusions: Buried glandular mucosa can be seen in surveillance biopsies after treatment with RFA for dysplastic Barrett's esophagus. As RFA is well tolerated, patients with this finding can be retreated. The clinical importance of this entity remains to be determined and further follow-up will be necessary to determine clearance rates of these changes.