Radiofrequency ablation of Barrett's esophagus

The role of ablation in the treatment of dysplastic Barrett's esophagus

Endoscopic eradication therapy for Barrett's esophagus has been established as an effective management strategy for patients with Barrett's esophagus with dysplasia and early esophageal cancer. Among the endoscopic therapies, ablation techniques such as radiofrequency ablation and cryoablation are effective primary treatment interventions with acceptable low complication rates forming the spectrum of a multimodal approach. Appropriate selection of patients, high-definition endoscopic evaluation, and dedicated histological assessment are important cornerstones to help navigate to the best effective treatment method. Carefully structured surveillance programs and preventive measures will be needed to provide long-term durability for maintaining complete remission.

Feasibility of optical coherence tomography for the evaluation of Barrett's mucosa buried underneath esophageal squamous epithelium

OBJECTIVES

The evaluation of Barrett's glands buried underneath esophageal squamous epithelium becomes increasingly important to achieve curative treatments. However, clinically available endoscopies have critical limitations in depicting the subsurface structure, resulting in non-curative treatments. Optical coherence tomography (OCT) can acquire a high-resolution cross-sectional image, equivalent to an 'optical biopsy'. We aimed to assess the feasibility of the in vivo use of probe-type OCT imaging to evaluate Barrett's mucosa buried underneath esophageal squamous epithelium METHODS: We conducted a single-center prospective study with 14 consecutive patients with Barrett's adenocarcinoma from 2008 to 2014. The enrolled patients were examined by a probe-type OCT in vivo, followed by en bloc endoscopic submucosal dissection (ESD) with electric marking. Then, the one-to-one correlations between the OCT images of the buried mucosa and their histological assessment were examined.

RESULTS

The overall accuracy, sensitivity, specificity, positive predictive value and negative predictive value of the buried mucosa in the OCT imaging were 85.7% (12/14), 77.8% (7/9), 100% (5/5), 100% (7/7) and 71.4% (5/7), respectively. However, OCT could not easily distinguish non-dysplastic glands from dysplastic glands. Additionally, the linear distance from the histological squamo-columnar junction in correct cases tended to be longer than that in incorrect cases (mm, median [range]: 2.0 [0.7-7.5] vs. 0.5 [0.5-0.5]).

CONCLUSIONS

We demonstrated, for the first time, that pre-operative OCT imaging might be feasible for detecting the oral side extension of buried Barrett's mucosa to remove the entire area with malignant potential by ESD. This article is protected by copyright. All rights reserved.

Ablative Endoscopic Therapies for Barrett's-Esophagus-Related Neoplasia

Barrett's esophagus (BE) is more common in developed countries. Endoscopic therapy is an effective treatment method in management of dysplastic BE. Ablation by thermal energy, freezing, or photochemical injury completely eradicates dysplasia and specialized intestinal metaplasia resulting in neosquamation of esophagus. Among the ablative modalities, radiofrequency ablation (RFA) is the most studied with safe, effective, and durable long-term outcomes. Cryotherapy, argon plasma coagulation, and photodynamic therapy can be offered in select patients when RFA is unavailable, has failed, or is contraindicated. Future research on natural disease progression, biomarkers, advanced imaging, and application of endoscopic techniques will lead to better clinical outcomes for BE-associated neoplasia.

Comparison of the long-term outcomes of endoscopic resection for superficial squamous cell carcinoma and adenocarcinoma of the esophagus in Japan

OBJECTIVES

Few studies have simultaneously evaluated the long-term outcomes of endoscopic resection (ER) for squamous cell carcinoma (SCC) and adenocarcinoma (AC) of the esophagus in Japan. The objective of this study was to evaluate the long-term outcomes of ER for superficial esophageal cancer in consecutive patients.

METHODS

This was a retrospective study from a single institution. From April 2001 to June 2012, 204 patients with SCC and 26 patients with AC were included from a total of 355 consecutive patients who were treated by esophageal ER at the Tohoku University Hospital. Patients with submucosal invasion deeper than 200 μm and lymphovascular involvement were excluded. The intervention followed was endoscopic therapy.

RESULTS

Overall survival, disease-free survival, and recurrence rates were evaluated as long-term outcomes. In the SCC group, during the median observation time of 36.5 months (range, 6-120 months), 22 (10.8%) patients experienced metachronous recurrence, 4 (2.0%) patients experienced local recurrence, and 27 (13.2%) patients died from causes unrelated to SCC. In the AC group, during the median observation time of 45.5 months (range, 6-131 months), one patient (3.8%) experienced metachronous recurrence and two (7.7%) died from causes unrelated to AC. The cumulative 5-year overall survival rates were not significantly different between SCC (75.9%) and AC (88.9%) (P=0.120). The cumulative 5-year disease-free survival rates of SCC (57.1%) were significantly lower than those of AC (85.2%; P=0.017). The cumulative 5-year recurrence rates of SCC (32.0%) were significantly higher than those of AC (4.2%; P=0.023).

CONCLUSIONS

The rate of recurrence after ER was higher in patients with SCC than that in patients with AC. These findings suggest that, by detecting AC of the esophagus earlier, a satisfactory prognosis without recurrence can be expected after ER in Japan, and more rigorous endoscopic follow-up is necessary after ER in patients with SCC than in those with AC.

Endoscopic resection (endoscopic submucosal dissection/endoscopic mucosal resection) for superficial Barrett's esophageal cancer

Recently developed endoscopic resection (endoscopic submucosal dissection [ESD]/ endoscopic mucosal resection) has dramatically changed the therapeutic approach for Barrett's esophageal cancer. The rationale for endoscopic resection is that lesions confined to the mucosal layer have negligible risk for developing lymph node metastasis and can be successfully eradicated by endoscopic treatment as a curative treatment with minimal invasiveness. According to some reports that analyzed the rate of lymph-node involvement relative to the depth of mucosal or submucosal tumor infiltration, endoscopic resection is clearly indicated for intramucosal carcinoma and might be extended to lesions with invasion into the submucosa (<200 μm, sm1) because of the low risk for lymph node metastasis. Most Japanese experts recommend ESD for Barrett's esophageal cancer after accurate diagnosis of the margin of cancer using narrow band imaging with magnifying endoscopy because of its high curative rate. However, few studies have evaluated the long-term outcomes of endoscopic resection for Barrett's esophageal cancer in Japan. Further investigations should be conducted to establish endoscopic resection for Barrett's esophageal cancer.

Endoscopic resection techniques and ablative therapies for Barrett’s neoplasia

Esophageal adenocarcinoma is the most rapidly increasing cancer in western countries. High-grade dysplasia (HGD) arising from Barrett’s esophagus (BE) is the most important risk factor for its development, and when it is present the reported incidence is up to 10% per patient-year. Adenocarcinoma in the setting of BE develops through a well known histological sequence, from non-dysplastic Barrett’s to low grade dysplasia and then HGD and cancer. Endoscopic surveillance programs have been established to detect the presence of neoplasia at a potentially curative stage. Newly developed endoscopic treatments have dramatically changed the therapeutic approach of BE. When neoplasia is confined to the mucosal layer the risk for developing lymph node metastasis is negligible and can be successfully eradicated by an endoscopic approach, offering a curative intention treatment with minimal invasiveness. Endoscopic therapies include resection techniques, also known as tissue-acquiring modalities, and ablation therapies or non-tissue acquiring modalities. The aim of endoscopic treatment is to eradicate the whole Barrett’s segment, since the risk of developing synchronous and metachronous lesions due to the persistence of molecular aberrations in the residual epithelium is well established.