Ablation of Barrett's epithelium: the promise and the problems

Barrett's esophagus: endoscopic treatments I

The following on endoscopic treatments of Barrett's esophagus includes commentaries on indications for endoscopic treatments; endo-luminal plication procedures; the cellular modifications induced by the endoscopic ablation therapies; eradication by banding without resection; the evaluation of complete ablation; recurrence after ablation; association of antireflux surgery; radiofrequency ablation; and nondysplastic Barrett's esophagus.

[Endoscopic argon plasma thermo-coagulation of Barrett's esophagus using different powers: histopathological and post procedure symptons analysis]

OBJECTIVE

To establish the ideal power to be employed in order to get the effective ablation and the lowest rate of symptoms at argon plasma thermocoagulation in Barrett's esophagus (BE).

METHODS

Twenty-eight asymptomatic patients with BE, were randomly divided in two groups of different ablation powers, 50W or 70W. After endoscopic ablation and biopsies from the treated area for histological analyses, symptoms were evaluated through a questionnaire answered by phone.

RESULTS

Thirteen patients without specialized columnar metaplasia were excluded and the remaining fifteen patients, seven men (46,7%) and eight women (53,3%), with an average age of 53 years +10,4, composed the two groups: 10 patients at the 70W power and 5 at the 50W power group. There was no significant difference between the groups regarding age, BE extent, percentage of coagulated esophageal circumference and the duration of symptoms. Pain was the most important symptom, with a mean duration of 10,3 + 9,7 days. When power was compared to symptoms, although not statistically significant, a moderate negative correlation was noted. Endoscopic biopsies showed ablation restricted to the mucosa's superficial layer in 40% of the cases in the lower power group, and only 10% in the higher power group, although deeper layers of the mucosa were compromised. There were no statistical significant differences when comparing the different powers to the penetration through the mucosa's layers and the symptoms.

CONCLUSION

There are evidences that the 70W potency argon plasma coagulation for BE leads to a lower incidence of residual specialized columnar metaplasia under the new scamous epithelium.

Banding without resection (endoscopic mucosal ligation) as a novel approach for the ablation of short-segment Barrett's epithelium: results of a pilot study

OBJECTIVES

During an endoscopic variceal ligation, we banded a varix with an overlying tongue of Barrett's epithelium (BE). One month later, the tongue was no longer visible, suggesting that banding could be used to eradicate BE.

AIM

To assess the safety and efficacy of banding without resection (BWR) using a variceal banding device for eradicating BE.

METHODS

From April 2004 through September 2005, 30 patients with BE were treated with BWR plus omeprazole 20 mg t.i.d. BWR was repeated monthly until two consecutive endoscopic and histological examinations showed no BE. Thirty Barrett's patients treated with omeprazole 20 mg t.i.d. alone served as a control group.

RESULTS

The BWR treatment group comprised 29 patients with short-segment BE (SSBE) and one with long-segment disease, whereas all 30 of the control patients had SSBE. During a median follow-up of 16.9 months (range 10-24 months), complete eradication of BE was achieved in 29 of 30 patients (97%) in the BWR group. In contrast, BE persisted in all 30 control patients during the same period (P < 0.0005). The mean total number of bands applied per patient was 6.1 (range 1-14) and the mean number of sessions for complete eradication was 3.1 (range 1-7). Adverse events included only mild chest pain and dysphagia that resolved within days.

CONCLUSIONS

BWR appears to be a safe, effective, simple, and widely available technique for eradicating SSBE. This is a pilot study and we do not recommend the ablation of nondysplastic BE at this time. Further studies are needed.

Abnormal expression of biomarkers in incompletely ablated Barrett's esophagus

OBJECTIVE

The aim of this study was to evaluate expression of cancer risk-associated biomarkers in columnar epithelium at squamocolumnar junctions produced by an ablation procedure and proton pump inhibitors in incompletely ablated Barrett's esophagus (BE) patients that were nondysplastic prior to ablation.

SUMMARY BACKGROUND DATA

Ablation of BE to squamous epithelium is achievable by combining a re-injury method with acid suppression. We previously reported that, when there is complete ablation, the neo-squamous epithelium is normal histologically and in biomarker expression. However, squamous islands observed after prolonged use of PPIs were associated with abnormalities in p53 expression and Ki-67 labeling.

METHODS

Twenty-one nondysplastic BE cases with incomplete ablation were evaluated for the expression of Ki-67 (proliferation), cyclooxygenase-2 (COX-2), and p53 by immunohistochemistry.

RESULTS

Pre-ablation biopsies showed the normal staining patterns in columnar epithelium, ie, normal Ki-67 labeling, rare positive COX-2 staining of interstitial cells, and negative or mild staining for p53 in the majority of patients' biopsies. However, post-ablation biopsies demonstrated abnormal staining patterns in the glandular area at the new squamocolumnar junctions. In 13 of 21 post-ablation cases (62%), increased Ki-67 staining was seen in BE glands. In 8 of 21 patients (38%), increased COX-2 expression was seen in columnar epithelium. Similarly, in 8 of 21 post-ablation junctions (38%), there was increased p53 staining.

CONCLUSIONS

Our findings of increased expression of cancer-associated biomarkers in incompletely ablated BE patients raise a cautionary note regarding this procedure. We hypothesize that newly formed junctions contain cells undergoing replication, differentiation, etc, and are thus more susceptible to genomic damage.

Barrett's esophagus: combined treatment using argon plasma coagulation and laparoscopic antireflux surgery

The treatment of Barrett's esophagus is still controversial. Actually, the only method to prevent the development to cancer is endoscopic surveillance, which ensures good results in terms of long-term survival. An ideal treatment capable of destroying columnar metaplasia, followed by squamous epithelium regeneration could potentially result in a decrease of the incidence of adenocarcinoma. Recently most ablative techniques were used, such as photodynamic therapy, ablation therapy with Nd-YAG laser or argon plasma coagulation and endoscopic mucosal resection. We started a prospective study in January 1998, enrolling 94 patients affected by Barrett's esophagus and candidates for antireflux repair in order to assess the effectiveness and the results of endoscopic coagulation with argon plasma combined with surgery in the treatment of uncomplicated Barrett's esophagus. All patients underwent endoscopic treatment with argon plasma; we observed complete response in 68 patients (72.34%), 27 of them (39.7%) underwent antireflux surgery and the other 41 continued medical therapy. Post-operatively 19 patients (70%) underwent regular surveillance endoscopies and in two cases metaplasia recurred. The final objective of these combined treatments should be the complete eradication of metaplastic mucosa. Our experience was that argon plasma coagulation combined with antireflux surgery or proton pump inhibitor therapy gave satisfactory results, even if follow-up is too short to evaluate the potential evolution of metaplasia to cancer. For this reason, we recommend that this technique should be done only in specialized centres and that these patients continue their endoscopic surveillance program.