Efficacy and safety of Hybrid-APC for the ablation of Barrett's esophagus

Hybrid argon plasma coagulation for the treatment of Barrett's esophagus: A prospective, multicenter study

BACKGROUND

The incidence of Barrett's esophagus (BE) in China is lower compared to the Western populations. Hence, studies conducted in the Chinese population has been limited. The current treatment options available for BE treatment includes argon plasma coagulation (APC), radiofrequency ablation and cryoablation, all with varying degrees of success.

AIM

To determine the efficacy and safety of HybridAPC in the treatment of BE.

METHODS

The study cohort consisted of patients with BE who underwent HybridAPC ablation treatment. These procedures were performed by seven endoscopists from different tertiary hospitals. The duration of the procedure, curative rate, complications and recurrent rate by 1-year follow-up were recorded.

RESULTS

Eighty individuals were enrolled for treatment from July 2017 to June 2020, comprising of 39 males and 41 females with a median age of 54 years (range, 30 to 83 years). The technical success rate of HybridAPC was 100% and the overall curative rate was 98.15%. No severe complications occurred during the operation. BE cases were classified as short-segment BE and long-segment BE. Patients with short-segment BE were all considered cured without complications. Thirty-six patients completed the one-year follow-up without recurrence. Twenty-four percent had mild dysplasia which were all resolved with one post-procedural treatment. The mean duration of the procedure was 10.94 ± 6.52 min.

CONCLUSION

Treatment of BE with HybridAPC was found to be a simple and quick procedure that is safe and effective during the short-term follow-up, especially in cases of short-segment BE. This technique could be considered as a feasible alternative ablation therapy for BE.

Efficacy and Safety of Argon Plasma Coagulation for the Ablation of Barrett's Esophagus: A Systemic Review and Meta-Analysis

Background/Aims

Argon plasma coagulation (APC) is an alternate ablative method to radiofrequency ablation for the treatment of Barrett's esophagus (BE), and it is preferred due to its lower cost and widespread availability. The present meta-analysis aimed to analyze the safety and efficacy of APC for the management of BE.

Methods

A literature search from January 2000 to November 2022 was done for studies analyzing the outcome of APC in BE. The primary outcomes were clearance rate of intestinal metaplasia and adverse events (AE). Pooled event rates were expressed with summative statistics.

Results

A total of 38 studies were included in the final analysis. The pooled event rate for clearance rate of intestinal metaplasia with APC in BE was 86.8% (95% confidence interval [CI], 83.5% to 90.2%), with high-power and hybrid APC having a higher rate compared to standard APC. The pooled incidence of AE with APC in BE was 22.5% (95% CI, 15.3% to 29.7%), without any significant difference between the subgroups, with self-limited chest pain being the commonest AE. The incidence of serious AE was only 0.4% (95% CI, 0.0% to 1.0%), while stricture development was seen only in 1.7% (95% CI, 0.9% to 2.6%) of cases. The pooled recurrence rate of BE was 16.1% (95% CI, 10.7% to 21.6%), with a significantly lower recurrence with high-power APC than standard APC.

Conclusions

High-power and hybrid APC seem to have an advantage over standard APC in terms of clearance rate and recurrence rate. Further studies are required to compare the efficacy and safety of hybrid APC with standard APC and radiofrequency ablation.

Radiofrequency ablation versus hybrid argon plasma coagulation in Barrett's esophagus: a prospective randomised trial

INTRODUCTION

Radiofrequency ablation (RFA) and hybrid argon plasma coagulation (H-APC) are established thermal ablation techniques for eradicating Barrett's esophagus after endoscopic resection. This study aimed to compare RFA with H-APC in relation to safety, effectiveness and eradication rates.

METHODS

After endoscopic resection, patients were randomly assigned to H-APC or RFA. A simplified H-APC technique was applied at 60 W. RFA was used with a 90° focal catheter and a simplified protocol of 12 J/cm2 × 3 or with a Halo 360° balloon and 10 J/cm2/cleaning/10 J/cm2. Eradication rates and adverse events were recorded. Patients received follow-up examinations after 3, 6, 12 and 24 months.

RESULTS

One hundred and one patients were finally included in the study (RFA N = 47, H-APC N = 54). The median follow-up period for short-term was 6.0 (CI 5.4-6.9) months and for long term 21 (CI 19.2.5-22.7) months. In total 211 ablations were performed. The eradication rates after long-term follow-up were 74.2% in the RFA group and 82.9% in the H-APC group. Post-interventional pain was significantly greater in the RFA group, with a mean score of 4.56/10 and duration of 7.54 days, in comparison with a mean score of 2.07/10 over 3.59 days in the H-APC group. Stenoses requiring intervention were noted in 3.7% of patients in the H-APC arm and 14.9% of those in the RFA arm.

CONCLUSIONS

Both ablation techniques have good results in relation to the eradication rate, with a slightly better outcome in the H-APC group. The severity and duration of pain were significantly greater in the RFA group.

Endoscopic Management of Dysplastic Barrett's Oesophagus and Early Oesophageal Adenocarcinoma

Barrett's oesophagus is a pathological condition whereby the normal oesophageal squamous mucosa is replaced by specialised, intestinal-type metaplasia, which is strongly linked to chronic gastro-oesophageal reflux. A correct endoscopic and histological diagnosis is pivotal in the management of Barrett's oesophagus to identify patients who are at high risk of progression to neoplasia. The presence and grade of dysplasia and the characteristics of visible lesions within the mucosa of Barrett's oesophagus are both important to guide the most appropriate endoscopic therapy. In this review, we provide an overview on the management of Barrett's oesophagus, with a particular focus on recent advances in the diagnosis and recommendations for endoscopic therapy to reduce the risk of developing oesophageal adenocarcinoma.

What Is "Cold" and What Is "Hot" in Mucosal Ablation for Barrett's Oesophagus-Related Dysplasia: A Practical Guide

Over the last two decades, endoscopic eradication therapy has been established as the therapeutic strategy of choice for patients with Barrett's oesophagus-related dysplasia and early oesophageal adenocarcinoma. With a multimodal approach, ablative therapies have been highly effective in achieving remarkable eradication rates of metaplastic epithelium with an acceptable adverse event rate. Among ablative techniques, radiofrequency ablation is currently considered as the first-line option as its efficacy and safety are strongly supported by relevant data. Nevertheless, radiofrequency ablation is costly, and not universally available, or applicable to every situation. Moreover, primary failure and recurrence rates are not negligible. In the last few years, cryotherapy techniques and hybrid argon plasma coagulation have been increasingly assessed as potential novel ablative therapies. Preliminary data have been promising and suggest that they may even have a role as first-line options, alternatively to radiofrequency ablation. The aim of this review is to provide a practical guide for the ablation of Barrett's oesophagus, with emphasis on the different ablative options.

Hybrid Argon Plasma Coagulation for Barrett's Esophagus and for Colonic Mucosal Resection-A Systematic Review and Meta-Analysis

Hybrid argon plasma coagulation (hAPC) is a novel technique that combines conventional argon plasma coagulation and waterjet submucosal expansion. The aims of this metanalysis were to evaluate the efficacy and safety of hAPC in the setting of Barret's esophagus (BE) ablation and as an adjunct to colonic endoscopic mucosal resection (EMR). Four electronic databases were searched, and the results were analyzed by two independent authors. Random-effects meta-analyses of the proportions of endoscopic and histologic remission (for BE), recurrence, and post-procedure adverse events were performed using R. Studies' reporting quality was also assessed. From the 979 identified records, 13 studies were included (10 regarding BE and three colonic EMR). The pooled percentages of endoscopic and histologic remission after hAPC for BE were 95% (95% confidence interval [CI] 91-99, I² = 34) and 90% (95%CI 84-95, I² = 46), respectively, while major adverse events and recurrence were registered in 2% (95%CI 0-5, I² = 41) and 11% (95%CI 2-27, I² = 11), respectively. Concerning hAPC-assisted EMR, the pooled percentages of major adverse events and recurrence were 5% (95%CI 2-10, I² = 0) and 1% (95%CI 0-3, I² = 40). Evidence suggests that the main advantages of hAPC are the increase in safety in the setting of BE ablation and the reduction of local recurrence after colonic EMR. Trials comparing hAPC with standard strategies are required to support its use for these indications.

ArgoCap - feasibility and safety of a novel over-the-scope device to facilitate endoscopic APC treatment

INTRODUCTION

Argon plasma coagulation (APC) is an electrosurgical procedure used, among other indications, for treatment of dysplastic Barrett's mucosa. Homogeneous and safe application can be compromised by varying distances and suboptimal angle of the probe to the tissue. In this study, we present ArgoCap, a novel endoscopic device developed to facilitate endoluminal APC treatment. Objectives of this preclinical study were to assess feasibility and safety and to determine suitable APC settings.

MATERIAL AND METHODS

One-hundred and thirty-two APC treatments of predefined areas using various APC settings were performed ex vivo in the opened porcine esophagus. Depth of thermal injury was assessed histologically. Feasibility of APC treatment in different locations was examined in 20 explanted porcine esophagi and in first in vivo porcine applications.

RESULTS

APC treatment in all quadrants of the esophagus was feasible. Histologically, thermal effects involving the whole thickness of the mucosa were visible with all settings. APC with pulsed mode resulted in deep thermal damage with all power settings. No lesions of the muscular layer occurred using precise (E8, E9) and forced (10 W, 20 W) mode.

CONCLUSIONS

Esophageal APC using ArgoCap is feasible and safe. The device has the potential to improve APC treatment of larger mucosal areas.

[Current status in Barrett's esophagus]

Barrett's esophagus has been an important issue in clinical medicine for many years. In the 70 s of the last century, the association between gastroesophageal reflux disease and BE was detected. Only ten years later, the association between BE and adenocarcinoma of the esophagus was reported. Starting in the 90s in Europe, endoscopic resection and ablation have seen an expanding role in the management of BE. In analogy with other diseases, patients are undergoing individualized surveillance and treatment strategies. In non-neoplastic Barrett's esophagus, surveillance intervals are clearly defined by national and European guidelines. Only in case of malignant transformation of BE which may range from low-grade dysplasia to high-grade dysplasia and early Barrett's cancer, endoscopic therapy is indicated. At present, there are emerging techniques of artificial intelligence. Due to these rapid developments in BE management, it is important to keep an eye on the current status of BE management.

Barrett's Esophagus: An Updated Review

Barrett’s esophagus (BE) is a change in the distal esophageal mucosal lining, whereby metaplastic columnar epithelium replaces squamous epithelium of the esophagus. This change represents a pre-malignant mucosal transformation which has a known association with the development of esophageal adenocarcinoma. Gastroesophageal reflux disease is a risk factor for BE, other risk factors include patients who are Caucasian, age > 50 years, central obesity, tobacco use, history of peptic stricture and erosive gastritis. Screening for BE remains selective based on risk factors, a screening program in the general population is not routinely recommended. Diagnosis of BE is established with a combination of endoscopic recognition, targeted biopsies, and histologic confirmation of columnar metaplasia. We aim to provide a comprehensive review of the epidemiology, pathogenesis, screening and advanced techniques of detecting and eradicating Barrett’s esophagus.

Hybrid argon plasma coagulation in Barrett's esophagus: a systematic review and meta-analysis

BACKGROUND/AIMS

Patients with Barrett's esophagus are at increased risk of developing esophageal adenocarcinoma. Endoscopic therapies aim to eradicate dysplastic and metaplastic tissues. Hybrid argon plasma coagulation (hybrid-APC) utilizes submucosal fluid injection to create a protective cushion prior to ablation that shields the submucosa from injury. We performed a pooled meta-analysis to evaluate the safety and efficacy of hybrid-APC.

METHODS

We conducted a systematic search of major electronic databases in April 2022. Studies that included patients with dysplastic and non-dysplastic Barrett's esophagus undergoing treatment with hybrid-APC were eligible for inclusion. Outcome measures included complete remission of intestinal metaplasia (CR-IM), stricture formation, serious adverse events, and number of sessions necessary to achieve CR-IM.

RESULTS

Overall pooled CR-IM rate for patients undergoing hybrid-APC was 90.8% (95% confidence interval [CI], 0.872-0.939; I2=0%). Pooled stricture rate was 2.0% (95% CI, 0.005-0.042; I2=0%). Overall serious adverse event rate was 2.7% (95% CI, 0.007-0.055; I2=0%).

CONCLUSION

Results of the current meta-analysis suggest that hybrid-APC is associated with high rates of CR-IM and a favorable safety profile. Interpretation of these results is limited by the inclusion of retrospective cohort and case series data. Randomized controlled trials that standardize treatment and outcome evaluation protocols are necessary to understand how this treatment option is comparable to the current standards of care.

Management of Dysplastic Barrett's Esophagus and Early Esophageal Adenocarcinoma

While patients with Barrett's esophagus without dysplasia may benefit from endoscopic surveillance, those with low-grade dysplasia may be managed with either endoscopic surveillance or endoscopic eradication. Patients with Barrett's esophagus with high-grade dysplasia and/or intramucosal adenocarcinoma will generally require endoscopic eradication therapy. The management of Barrett's esophagus with dysplasia and early esophageal adenocarcinoma is predominantly endoscopic, with multiple effective methods available for the resection of raised neoplasia and ablation of flat neoplasia. High-dose proton-pump inhibitor therapy is advised during the treatment of Barrett's esophagus with dysplasia and early esophageal adenocarcinoma. After the endoscopic eradication of Barrett's esophagus and associated neoplasia, surveillance is required for the diagnosis and retreatment of recurrence or progression.

Hybrid argon plasma coagulation-assisted endoscopic mucosal resection for large sessile colon polyps to reduce local recurrence: a prospective pilot study

BACKGROUND

Endoscopic mucosal resection (EMR) of large, sessile colon polyps often results in incomplete resection with subsequent recurrence. The aim of this prospective pilot study was to evaluate the efficacy and safety of a novel technique, hybrid argon plasma coagulation-assisted EMR (hAPC-EMR), to remove large, sessile polyps.

METHODS

40 eligible patients underwent hAPC-EMR for the removal of one or more nonpedunculated colon polyps ≥ 20 mm. Participants were contacted 30 days post-procedure to assess for adverse events and were recommended to return for a surveillance colonoscopy at 6 months to assess for local recurrence.

RESULTS

At the time writing, 32 patients with 35 polyps (median size 27 mm; interquartile range 14.5 mm) resected by hAPC-EMR had undergone the 6-month follow-up colonoscopy. Recurrence rate was 0 % (95 % confidence interval [CI] 0-0) at follow-up. Post-polypectomy bleeding was experienced by three patients (7.5 %; 95 %CI 0.00-0.15), and no patients developed post-polypectomy syndrome.

CONCLUSION

These preliminary results showed 0 % local recurrence rate at 6 months and demonstrated the safety profile of hAPC-EMR. A large, randomized, controlled trial is required to confirm these results.

Endoscopic Diagnosis and Management of Barrett's Esophagus with Low-Grade Dysplasia

Barrett’s Esophagus is a common condition associated with chronic gastroesophageal reflux disease. It is well known that it has an association with a higher incidence of esophageal adenocarcinoma, but this neoplastic transformation is first preceded by the onset of low and high-grade dysplasia. The evaluation of low grade dysplastic esophageal mucosa is still controversial; although endoscopic surveillance is preferred, several minimally invasive endoscopic therapeutic approaches are available. Endoscopic mucosal resection and radiofrequency ablation are the most used endoscopic treatments for the eradication of low-grade dysplasia, respectively, for nodular and flat dysplasia. Novel endoscopic treatments are cryotherapy ablation and argon plasma coagulation, that have good rates of eradication with less complications and post-procedural pain.

Hybrid APC in Combination With Resection for the Endoscopic Treatment of Neoplastic Barrett's Esophagus: A Prospective, Multicenter Study

INTRODUCTION

The current therapy of neoplastic Barrett's esophagus (BE) consists of endoscopic resection plus ablation, with radiofrequency ablation as the best studied technique. This prospective trial assesses a potential alternative, namely hybrid argon plasma ablation.

METHODS

Consecutive patients with neoplastic BE undergoing ablation after curative endoscopic resection (89.6%) or primarily were included into this prospective trial in 9 European centers. Up to 5 ablation sessions were allowed for complete eradication of BE (initial complete eradication of intestinal metaplasia [CE-IM]), by definition including BE-associated neoplasia, documented by 1 negative endoscopy with biopsies. The main outcome was the rate of initial CE-IM in intention-to-treat (ITT) and per-protocol (PP) samples at 2 years. The secondary end points were the rate of recurrence-free cases (sustained CE-IM) documented by negative follow-up endoscopies with biopsies and immediate/delayed adverse events.

RESULTS

One hundred fifty-four patients (133 men and 21 women, mean age 64 years) received a mean of 1.2 resection and 2.7 ablation sessions (range 1-5). Initial CE-IM was achieved in 87.2% of 148 cases in the PP analysis (ITT 88.4%); initial BE-associated neoplasia was 98.0%. On 2-year follow-up of the 129 successfully treated cases, 70.8% (PP) or 65.9% (ITT) showed sustained CE-IM; recurrences were mostly endoscopy-negative biopsy-proven BE epithelium and neoplasia in 3 cases. Adverse events were seen in 6.1%.

DISCUSSION

Eradication and recurrence rates of Barrett's intestinal metaplasia and neoplasia by means of hybrid argon plasma coagulation at 2 years seem to be within expected ranges. Final evidence in comparison to radiofrequency ablation can only be provided by a randomized comparative trial.

Benefit, tolerance, and safety of hybrid argon plasma coagulation for treatment of Barrett's esophagus: US pilot study

Background and study aims  A novel technique for Barrett's esophagus (BE) ablation, termed hybrid APC, has recently been developed. The aims of this US pilot study were to evaluate the efficacy, tolerance and safety of hybrid APC for the treatment of BE. Patients and methods  Patients with biopsy-proven BE referred to our tertiary care center over a 12-month period for mucosal ablation were eligible for this study. Efficacy of ablation was measured on follow-up endoscopy by demonstrating either a reduction of visible BE or biopsies proving complete resolution of intestinal metaplasia (CRIM). To evaluate tolerance and safety, patients were called on post-procedure days 1 and 7. Results  Twenty-two patients with BE (4.5 % intramucosal carcinoma, 31.8 % high-grade dysplasia, 18.1 % low-grade dysplasia, 36.3 % non-dysplastic, 9.1 % indefinite for dysplasia) underwent 40 treatments with hybrid APC. All patients had endoscopic improvement of BE disease and 19 of 22 patients (86.4 %) achieved CRIM. With regard to tolerance, average pain scores (0 to 10 scale) on follow-up were 2.65 and 0.62 on days 1 and 7, respectively. With regards to safety, there were two treatment-related strictures (9.1 %) that required a single balloon dilation. Conclusions  Hybrid APC appears to be promising in the treatment of BE. The ablation protocol used in this study demonstrated efficacy, tolerability, and a safety profile similar to radiofrequency ablation. Given the significant price difference between hybrid APC and other modalities for Barrett's ablation, this modality may be more cost-effective. These results warrant further study in a large prospective multicenter trial.

Therapeutic Endoscopy and the Esophagus: State of the Art and Future Directions

Therapeutic gastrointestinal endoscopy is rapidly evolving, and this evolution is quite apparent for esophageal diseases. Minimally invasive endoluminal therapy now allows outpatient treatment of many esophageal diseases that were traditionally managed surgically. In this review article, we explore the most exciting new developments. We discuss the use of peroral endoscopic myotomy for treatment of achalasia and other related diseases, as well as the modifications that have allowed its use in treatment of Zenker diverticulum. We cover endoscopic treatment of gastroesophageal reflux disease and Barrett's esophagus. Further, we explore advanced endoscopic resection techniques.

Barrett's Esophagus: Diagnosis, Management, and Key Updates

Barrett's esophagus (BE) is the precursor lesion for esophageal adenocarcinoma (EAC) development. Unfortunately, BE screening/surveillance has not provided the anticipated EAC reduction benefit. Noninvasive techniques are increasingly available or undergoing testing to screen for BE among those with/without known risk factors, and the use of artificial intelligence platforms to aid endoscopic screening and surveillance will likely become routine, minimizing missed cases or lesions. Management of high-grade dysplasia and intramucosal EAC is clear with endoscopic eradication therapy preferred to surgery. BE with low-grade dysplasia can be managed with removal of visible lesions combined with endoscopic eradication therapy or endoscopic surveillance at present.

Fluid cushion protects against thermal damage during argon plasma coagulation

Background

Thermal damage to the muscle layer during mucosal application of argon plasma coagulation (APC) may be avoided by creating a fluid cushion within the submucosal layer, but the minimum injection volume needed or the ideal injection fluid are yet to be established. We conducted a systematic ex vivo study with this aim.

Methods

All experiments were performed in an ex vivo porcine gastrointestinal tract model. Five different fluids (saline, Glyceol, Gelafundin, Voluven, and Eleview) of different volumes were injected into the submucosa of different parts of the gastrointestinal tract. APC was applied to the mucosa at different power settings. Immediately after APC treatment, the temperature was measured through a thermocouple placed inside the fluid cushion, just on top of the muscle layer. The minimum volume of fluid needed to protect the muscle layer from thermal damage was determined.

Results

There was no difference in the temperature measured among the different injection fluids at the surface of the muscle, in all the locations, at equal injection volumes and power settings. The minimum amounts of fluid needed to protect the muscle layer were 2 and 3 mL for power settings of 30-90 W and 90-120 W, respectively.

Conclusions

Normal saline and 4 commercially available submucosal injection fluids possess similar thermal protective effects. To reduce the likelihood of thermal damage to deeper layers when APC is applied, a minimum injection volume of 3 mL is recommended if less than 90 W power will be utilized over 3 sec.

Endoscopic therapies for Barrett's esophagus

The management of Barrett's esophagus (BE) has evolved as newer technologies and novel methods are developed. Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) are the initial interventions of choice for nodular BE, with ESD reserved for endoscopists highly trained in the technique and for larger lesions that would warrant en bloc resection. Resection should then be followed by ablative therapy, which remains first line in the treatment of BE with dysplasia. Although there is a myriad of ablation techniques available to the endoscopist, this review has found that radiofrequency ablation (RFA) continues to have the most robust safety and efficacy data to support its use despite a relatively high rate of recurrence. Cryotherapy and Hybrid-APC appear to be safe and effective as RFA alternatives, but further trials are still needed to directly compare their outcomes to RFA and ultimately guide changes in treatment decisions.

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.

The evolution of endoscopic therapy for Barrett's esophagus

Barrett’s esophagus is the condition in which a metaplastic columnar epithelium replaces the stratified squamous epithelium that normally lines the distal esophagus. The condition develops as a consequence of chronic gastroesophageal reflux disease and predisposes the patient to the development of esophageal adenocarcinoma. The diagnosis and management of Barrett’s esophagus have undergone dramatic changes over the years and continue to evolve today. Endoscopic eradication therapy has revolutionized the management of dysplastic Barrett’s esophagus and early esophageal adenocarcinoma by significantly reducing the morbidity and mortality associated with the prior gold standard of therapy, esophagectomy. The purpose of this review is to highlight current principles in the management and endoscopic treatment of this disease.

Hybrid argon plasma coagulation for Barrett's esophagus

Video 1Hybrid APC for Barrett's esophagus.

Endoscopic management of Barrett's esophagus: Western perspective of current status and future prospects

Barrett's esophagus (BE) is a precursor to esophageal adenocarcinoma and current practice is to establish endoscopic surveillance once diagnosed, in order to identify early dysplasia and neoplasia that has the potential to undergo endoscopic eradication therapy (EET). Before embarking upon EET the clinical team has a duty to consider all viable options and come to a plan based on recent evidence. The therapeutic approach varies greatly but largely adheres to the mantra of 'Detect-Resect-Ablate', in which high-quality endoscopy identifies BE associated pathology, associated lesions (if present) undergo safe endoscopic resection and remaining intestinal metaplasia in the esophagus is ablated to prevent recurrence of dysplasia. In this review, current practice, pitfalls, complications, and the future perspectives on practice in this field are discussed. The Western perspective is focused on here, with an outline of the differences in clinical practice with Asian nations and attempts to bridge these differences.

Barrett's Esophagus and Intestinal Metaplasia

Intestinal metaplasia refers to the replacement of the differentiated and mature normal mucosal epithelium outside the intestinal tract by the intestinal epithelium. This paper briefly describes the etiology and clinical significance of intestinal metaplasia in Barrett’s esophagus. This article summarizes the impact of intestinal metaplasia on the diagnosis, monitoring, and treatment of Barrett’s esophagus according to different guidelines. We also briefly explore the basis for the endoscopic diagnosis of intestinal metaplasia in Barrett’s esophagus. The identification techniques of goblet cells in Barrett’s esophagus are also elucidated by some scholars. Additionally, we further elaborate on the current treatment methods related to Barrett’s esophagus.

Role of argon plasma coagulation in treatment of esophageal varices

With the development of endoscopic therapy, argon plasma coagulation (APC) has been widely used by endoscopists. It has many advantages, such as simple to operate, low cost, and minimal invasiveness. Because of its capability of lesion ablation and hemostasis, APC has several indications in the gastrointestinal tract. One of them is esophageal varices. The aim of this review is to summarize the research on APC in this field to provide a reference for clinical practice.

Endoscopic mucosal ablation - an alternative treatment for colonic polyps: Three case reports

BACKGROUND

Endoscopic resection of non-invasive lesions is now the standard of care for lesions in the GI tract. However, resection techniques require extensive training, are not available in all endoscopy centers and are prone to complications. Endoscopic mucosal ablation (EMA) is a combination of resection and ablation techniques and it may offer an alternative in the management of such lesions.

CASE SUMMARY

In this case series we report the successful treatment of three flat colonic polyps using the EMA technique. Two lesions were treatment naïve and 1 was a recurrence after an endoscopic mucosal resection. The sizes ranged from 2 to 4 cm. All three polyps were ablated successfully with no immediate or delayed complications. The recurrence rate at 1 year of follow up was 0%.

CONCLUSION

Based on this initial experience, we conclude that EMA is a safe and effective technique for the treatment of non-invasive colonic polyps when endoscopic resection techniques are not available.

Indications, contraindications and limitations of endoscopic therapy for Barrett's esophagus and early esophageal adenocarcinoma

Endoscopic eradication therapy (EET) has revolutionized management of Barrett's esophagus (BE)-associated neoplasia, traditionally treated by esophagectomy, which carries very high mortality and morbidity. EET, usually performed in the outpatient setting, has a safe risk profile. It is indicated in patients with BE with high-grade dysplasia and intramucosal cancer, confirmed, and persistent low-grade dysplasia, and in highly selected cases of non-dysplastic BE and submucosal cancers. Multiple EET modalities are available and can be categorized into two groups: ablation therapies and resection techniques with resection techniques usually reserved for nodular/raised lesions or lesions with suspected neoplasia. Patients usually require multiple ablation sessions with a goal of achieving complete eradication of metaplasia. Despite very good results, EET has its limitations and is not 100% effective: it targets a small subset of patients along the spectrum of BE and esophageal adenocarcinoma, as most patients with esophageal adenocarcinoma remain asymptomatic until the disease has progressed to advanced stages. Post-ablation surveillance is mandatory, as recurrences are common. An area of concern is buried metaplasia reported to occur following ablation therapy and thought to be from de novo growth of metaplastic tissue underneath the neosquamous epithelium, following ablation. The focus of this review article is to present the indications, contraindications and limitations of EET.

Management of Barrett’s esophagus with dysplasia refractory to radiofrequency ablation

Radiofrequency ablation (RFA) is very effective for eradication of flat Barrett’s mucosa in dysplastic Barrett’s esophagus after endoscopic resection of raised lesions. However, in a minority of the time, RFA may be ineffective at eradication of the Barrett’s mucosa. Achieving complete eradication of intestinal metaplasia can be challenging in these patients. This review article focuses on the management of patients with dysplastic Barrett’s esophagus refractory to RFA therapy. Management strategies discussed in this review include optimizing the RFA procedure, optimizing acid suppression (with medical, endoscopic, and surgical management), cryotherapy, hybrid argon plasma coagulation, and EndoRotor resection.

Volumetric laser endomicroscopy in Barrett's esophagus: ready for primetime

Barrett's esophagus (BE) is the condition where intestinal metaplastic changes are found in the normal stratified squamous epithelium of the esophagus predisposing an individual to dysplasia and esophageal adenocarcinoma (EAC). It tends to affect males and is often the result of chronic gastroesophageal reflux disease (GERD). The current standard of therapy for diagnosing Barrett's is white light endoscopy (WLE) with biopsies obtained using the Seattle protocol. Multiple newer advanced modalities have been developed to improve diagnostic abilities, including volumetric laser endomicroscopy (VLE). This technique utilizes second generation optical coherence tomography (OCT) to provide an enhanced circumferential image to a depth of 3 mm with the potential for improved diagnostic yield for dysplasia, particularly submucosal lesions or lesions not seen by WLE. It has also been evaluated in guiding mapping of endotherapy as well as post therapy surveillance for recurrence. Although the results have been promising when used with current diagnostic standards, overall data are limited to support the routine use of VLE.

Hybrid Argon Plasma Coagulation for Treatment of Gastric Intestinal Metaplasia

Hybrid argon plasma coagulation (HybridAPC® [HAPC]) is an evolution of the standard argon plasma coagulation (APC) technology, where the application of APC is preceded by high-pressure needleless submucosal injection. APC is indicated for the ablation of benign and dysplastic mucosal lesions, such as vascular malformations or Barrett's mucosa. HAPC offers safety and efficacy advantages over standard APC because the submucosal injection acts as a heat sink that disperses energy. This ensures that the underlying muscularis propria remains unaffected, and only the mucosal layer is coagulated in its entirety. An 81-year-old Hispanic male was found to have a 1.2-cm mucosal nodule along the incisura of the stomach. Pathology of the biopsy specimen revealed high-grade dysplasia, and he subsequently underwent endoscopic ultrasound examination, which confirmed the presence of an isolated gastric nodule with no deep invasion of the muscularis propria, consistent with a uT1N0Mx endosonographic staging. He then underwent endoscopic submucosal dissection of the lesion. Pathology of the excised specimen confirmed the presence of multifocal high-grade dysplasia, arising in the background of extensive intestinal metaplasia. The deep margin was clear; however, the lateral resection margins showed focal involvement of intestinal metaplasia with low-grade dysplasia. Surveillance endoscopy confirmed the persistence of diffuse intestinal metaplasia. He was then treated with widespread HAPC due to the presence of underlying diffuse intestinal metaplasia in the stomach. HAPC is an effective and efficient treatment modality for mucosal lesions. In one series of 50 patients, 96% achieved complete macroscopic remission of Barrett's mucosa after a median of 3.5 APC sessions, and 85% achieved complete histological remission. HAPC is a promising therapeutic modality as a thermal injury is targeted, and the depth of injury is contained. This provides immediate procedural efficacy and safety benefits, and reduces subsequent complications when compared with standard APC. We anticipate that the applications of HAPC will continue to grow, as this modality is adopted into common procedural parlance. This case appears to be the first to describe the use of HAPC for definitive treatment of diffuse intestinal metaplasia.

AGA Clinical Practice Update on Endoscopic Treatment of Barrett's Esophagus With Dysplasia and/or Early Cancer: Expert Review

DESCRIPTION

The purpose of this best practice advice article is to describe the role of Barrett's endoscopic therapy (BET) in patients with Barrett's esophagus (BE) with dysplasia and/or early cancer and appropriate follow-up of these patients.

METHODS

The best practice advice provided in this document is based on evidence and relevant publications reviewed by the committee. BEST PRACTICE ADVICE 1: In BE patients with confirmed low-grade dysplasia, a repeat examination with high-definition white-light endoscopy should be performed within 3-6 months to rule out the presence of a visible lesion, which should prompt endoscopic resection. BEST PRACTICE ADVICE 2: Both BET and continued surveillance are reasonable options for the management of BE patients with confirmed and persistent low-grade dysplasia. BEST PRACTICE ADVICE 3: BET is the preferred treatment for BE patients with high-grade dysplasia (HGD). BEST PRACTICE ADVICE 4: BET should be preferred over esophagectomy for BE patients with intramucosal esophageal adenocarcinoma (T1a). BEST PRACTICE ADVICE 5: BET is a reasonable alternative to esophagectomy in patients with submucosal esophageal adenocarcinoma (T1b) with low-risk features (<500-μm invasion in the submucosa [sm1], good to moderate differentiation, and no lymphatic invasion) especially in those who are poor surgical candidates. BEST PRACTICE ADVICE 6: In all patients undergoing BET, mucosal ablation should be applied to 1) all visible esophageal columnar mucosa; 2) 5-10 mm proximal to the squamocolumnar junction and 3) 5-10 mm distal to the gastroesophageal junction, as demarcated by the top of the gastric folds (ie, gastric cardia) using focal ablation in a circumferential fashion. BEST PRACTICE ADVICE 7: Mucosal ablation therapy should only be performed in the presence of flat BE without signs of inflammation and in the absence of visible abnormalities. BEST PRACTICE ADVICE 8: BET should be performed by experts in high-volume centers that perform a minimum of 10 new cases annually. BEST PRACTICE ADVICE 9: BET should be continued until there is an absence of columnar epithelium in the tubular esophagus on high-definition white-light endoscopy and preferably optical chromoendoscopy. In case of complete endoscopic eradication, the neosquamous mucosa and the gastric cardia are sampled by 4-quadrant biopsies. BEST PRACTICE ADVICE 10: If random biopsies obtained from the neosquamous epithelium demonstrate intestinal metaplasia/dysplasia or subsquamous intestinal metaplasia, a repeat endoscopy should be performed and visible islands or tongues should undergo targeted focal ablation. BEST PRACTICE ADVICE 11: Intestinal metaplasia of the gastric cardia (without residual columnar epithelium in the tubular esophagus) should not warrant additional ablation therapy. BEST PRACTICE ADVICE 12: When consenting patients for BET, the most common complication of therapy to be quoted is post-procedural stricture formation, occurring in about 6% of cases. Bleeding and perforation occur at rates <1%. BEST PRACTICE ADVICE 13: After complete eradication (endoscopic and histologic) of intestinal metaplasia has been achieved with BET, surveillance endoscopy with biopsies should be performed at the following intervals: for baseline diagnosis of HGD/esophageal adenocarcinoma: at 3, 6, and 12 months and annually thereafter; and baseline diagnosis of low-grade dysplasia: at 1 and 3 years. BEST PRACTICE ADVICE 14: Endoscopic surveillance post therapy should be performed with high-definition white-light endoscopy, including careful inspection of the neosquamous mucosal and retroflexed inspection of the gastric cardia. BEST PRACTICE ADVICE 15: The approach to recurrent disease is similar to that of the initial therapy; visible recurrent nodular lesions require endoscopic resection, whereas flat areas of columnar mucosa in the tubular esophagus can be treated with mucosal ablation. BEST PRACTICE ADVICE 16: Patients should be counseled on cancer risk in the absence of BET, as well as after BET, to allow for informed decision-making between the patient and the physician.

Resection of early esophageal neoplasms: The pendulum swings from surgical to endoscopic management

Esophageal cancer is a highly lethal disease and is the sixth leading cause of cancer related mortality in the world. The standard treatment is esophagectomy which is associated with significant morbidity and mortality. This led to development of minimally invasive, organ sparing endoscopic therapies which have comparable outcomes to esophagectomy in early cancer. These include endoscopic mucosal resection and endoscopic submucosal dissection. In early squamous cell cancer, endoscopic submucosal dissection is preferred as it is associated with cause specific 5-year survival rates of 100% for M1 and M2 tumors and 85% for M3 and SM1 tumors and low recurrence rates. In early adenocarcinoma, endoscopic resection of visible abnormalities is followed by ablation of the remaining flat Barrett’s mucosa to prevent recurrences. Radiofrequency ablation is the most widely used ablation modality with others being cryotherapy and argon plasma coagulation. Focal endoscopic mucosal resection followed by radiofrequency ablation leads to eradication of neoplasia in 93.4% of patients and eradication of intestinal metaplasia in 73.1% of patients. Innovative techniques such as submucosal tunneling with endoscopic resection are developed for management of submucosal tumors of the esophagus. This review includes a discussion of various endoscopic techniques and their clinical outcomes in early squamous cell cancer, adenocarcinoma and submucosal tumors. An overview of comparison between esophagectomy and endoscopic therapy are also presented.

Initial Experience with Hybrid Argon Plasma Coagulation as a Novel Local Treatment Method for Tracheobronchial Mucoepidermoid Carcinoma

Tracheobronchial mucoepidermoid carcinoma (MEC) is a type of salivary gland tumor. Surgical resection is the main treatment for MEC, but it is associated with risks. Hybrid argon plasma coagulation (HybridAPC®) is an innovative technique combining APC with a water cushion function which can be used for the treatment of MEC. We aimed to evaluate the efficacy and safety of HybridAPC for MEC in 2 patients diagnosed with MEC based on histological examination of biopsies. Full preoperative assessments were done by white-light bronchoscopy, autofluorescence imaging, narrow-band imaging, and radial probe endobronchial ultrasound. HybridAPC was administered after these evaluations. Both patients were followed up for more than 3 months. HybridAPC ablation was completed successfully, with no complications. HybridAPC thus appears to be a safe and efficient treatment for MEC.

Issues and controversies in esophageal inlet patch

The proximal esophagus is rarely examined, and its inspection is often inadequate. Optical chromoendoscopy techniques such as narrow band imaging improve the detection rate of inlet patches in the proximal esophagus, a region in which their prevalence is likely underestimated. Various studies have reported correlations between these esophageal marks with different issues such as Barrett's esophagus, but these findings remain controversial. Conflicting reports complicate the process of interpreting the clinical features of esophageal inlet patches and underestimate their importance. Unfortunately, the limited clinical data and statistical analyses make reaching any conclusions difficult. It is hypothesized that inlet patches are correlated with various esophageal and extraesophageal symptoms, diagnoses and the personalized therapeutic management of patients with inlet patches as well as the differential diagnosis for premalignant lesions or early cancers. Due to its potential underdiagnosis, there are no consensus guidelines for the management and follow up of inlet patches. This review focuses on questions that were raised from published literature on esophageal inlet patches in adults.

Radiofrequency ablation compared with argon plasma coagulation after endoscopic resection of high-grade dysplasia or stage T1 adenocarcinoma in Barrett's esophagus: a randomized pilot study (BRIDE)

BACKGROUND AND AIMS

Endoscopic resection (ER) is safe and effective for Barrett's esophagus (BE) containing high-grade dysplasia (HGD) or mucosal adenocarcinoma (T1A). The risk of metachronous neoplasia is reduced by ablation of residual BE by using radiofrequency ablation (RFA) or argon plasma coagulation (APC). These have not been compared directly. We aimed to recruit up to 100 patients with BE and HGD or T1A confirmed by ER over 1 year in 6 centers in a randomized pilot study.

METHODS

Randomization was 1:1 to RFA or APC (4 treatments allowed at 2-month intervals). Recruitment, retention, dysplasia clearance, clearance of benign BE, adverse events, healthcare costs, and quality of life by using EQ-5D, EORTC QLQ-C30, or OES18 were assessed up to the end of the trial at 12 months.

RESULTS

Of 171 patients screened, 76 were randomized to RFA (n = 36) or APC (n = 40). The mean age was 69.7 years, and 82% were male. BE was <5 cm (n = 27), 5 to 10 cm (n = 45), and >10 cm (n = 4). Sixty-five patients completed the trial. At 12 months, dysplasia clearance was RFA 79.4% and APC 83.8% (odds ratio [OR] 0.7; 95% confidence interval [CI], 0.2-2.6); BE clearance was RFA 55.8%, and APC 48.3% (OR 1.4; 95% CI, 0.5-3.6). A total of 6.1% (RFA) and 13.3% (APC) had buried BE glands. Adverse events (including stricture rate after starting RFA 3/36 [8.3%] and APC 3/37 [8.1%]) and quality of life scores were similar, but RFA cost $27491 more per case than APC.

CONCLUSION

This pilot study suggests similar efficacy and safety but a cost difference favoring APC. A fully powered non-inferiority trial is appropriate to confirm these findings. (Clinical trial registration number: NCT01733719.).

Endoscopic resection for early esophageal carcinoma

Endoscopic resection for early esophageal cancer is a very precise endoscopic surgical technique and having experience in endoscopic resection is mandatory to perform these kinds of procedures safely. In case of adequate resection and favorable histological outcome, long-term prognosis of the patient is excellent. The basic principle for endoscopic treatment of early adenocarcinoma is based on the fact that the risk of lymph node metastasis gradually increases with the depth of invasion. Inspection and evaluation of all mucosal and submucosal lesions need to be done carefully before endoscopic resection. Endoscopic resection of mucosal (T1m1-3) and superficial submucosal (T1sm1) adenocarcinoma can be curative as well as for superficial mucosal (T1m1-m2) squamous cell carcinoma. In Paris type I lesions in Barrett's esophagus and for early squamous cell carcinoma endoscopic submucosal dissection (ESD) is the preferred option. The risk of severe adverse events associated with endoscopic resection are low. Most adverse events are managed endoscopically and can be treated conservatively. Endoscopic radiofrequency ablation is the most widely used ablation technique for Barrett's epithelium and highly effective to achieve full remission of dysplasia and intestinal metaplasia. The role of radiofrequency ablation in the treatment armamentarium in squamous cell carcinoma of the esophagus has still to be determined.

Early detection and therapeutics

Early detection, including cancer screening and surveillance, is emerging as one of the most important topics in modern oncology. Because symptomatic presentation remains the predominant route to cancer diagnosis, there is a growing interest in developing techniques to detect the disease at an early, curative stage. Moreover, growing understanding of cancer biology has paved the way for prevention studies with the focus on therapeutic interventions for premalignant conditions. Where there is a recognisable precursor stage, such as a colorectal adenoma or Barrett's metaplasia, the removal of abnormal tissue prevents the development of cancer and enables stratification of the patient to a high-risk group requiring further surveillance. Here, we provide a review of the available technologies for early diagnosis and minimally-invasive treatment.

Endoscopic foregut surgery and interventions: The future is now. The state-of-the-art and my personal journey

In this paper, I reviewed the emerging field of endoscopic surgery and present data supporting the contention that endoscopy can now be used to treat many foregut diseases that have been traditionally treated surgically. Within each topic, the content will progress as follows: "lessons learned", "technical considerations" and "future opportunities". Lessons learned will provide a brief background and update on the most current literature. Technical considerations will include my personal experience, including tips and tricks that I have learned over the years. Finally, future opportunities will address current unmet needs and potential new areas of development. The foregut is defined as "the upper part of the embryonic alimentary canal from which the pharynx, esophagus, lung, stomach, liver, pancreas, and part of the duodenum develop". Foregut surgery is well established in treating conditions such as gastroesophageal reflux disease (GERD), achalasia, esophageal diverticula, Barrett's esophagus (BE) and esophageal cancer, stomach cancer, gastric-outlet obstruction, and obesity. Over the past decade, remarkable progress in interventional endoscopy has culminated in the conceptualization and practice of endoscopic foregut surgery for various clinical conditions summarized in this paper. Regarding GERD, there are now several technologies available to effectively treat it and potentially eliminate symptoms, and the need for long-term treatment with proton pump inhibitors. For the first time, fundoplication can be performed without the need for open or laparoscopic surgery. Long-term data going out 5-10 years are now emerging showing extended durability. In respect to achalasia, per-oral endoscopic myotomy (POEM) which was developed in Japan, has become an alternative to the traditional Heller's myotomy. Recent meta-analysis show that POEM may have better results than Heller, but the issue of post-POEM GERD still needs to be addressed. There is now a resurgence of endoscopic treatment of Zenker's diverticula with improved technique (Z-POEM) and equipment; thus, patients are choosing flexible endoscopic treatment as opposed to open or rigid endoscopy options. In regard to BE, endoscopic submucosal dissection (ESD) which is well established in Asia, is now becoming more mainstream in the West for the treatment of BE with high grade dysplasia, as well as early esophageal cancer. In combination with all the ablation technologies (radiofrequency ablation, cryotherapy, hybrid argon plasma coagulation), the entire spectrum of Barrett's and related dysplasia and early cancer can be managed predominantly by endoscopy. Importantly, in regard to early gastric cancer and submucosal tumors (SMTs) of the stomach, ESD and full thickness resection (FTR) can excise these lesions en-bloc and endoscopic suturing is now used to close large defects and perforations. For treatment of patients with malignant gastric outlet obstruction (GOO), endoscopic gastro-jejunostomy is now showing better results than enteral stenting. G-POEM is also emerging as a treatment option for patients with gastroparesis. Obesity has become an epidemic in many western countries and is becoming also prevalent in Asia. Endoscopic sleeve gastroplasty (ESG) is now becoming an established treatment option, especially for obese patients with body mass index between 30 and 35. Data show an average weight loss of 16 kg after ESG with long-term data confirming sustainability. Finally, in respect to endo-hepatology, there are many new endoscopic interventions that have been developed for patients with liver disease. Endoscopic ultrasound (EUS)-guided liver biopsy and EUS-guided portal pressure measurement are exciting new frontiers for the endo-hepatologists.

Endoscopic therapy for confirmed low-grade dysplasia in Barrett's esophagus

Barrett's esophagus (BE) is a premalignant condition characterized by replacement of the esophageal lining with metastatic columnar epithelium. To date, the management in case of confirmed low-grade dysplasia (LGD) remains controversial. In this article we summarize the available endoscopic options and their results in terms of efficacy and safety in the treatment of confirmed LGD in BE.

Endoscopic management of dysplasia and early oesophageal cancer

In the past decade there have been technological advances in Endoscopic Eradication Therapy (EET) for the management of patients with oesophageal neoplasia and early cancer. Multiple endoscopic techniques now exist for both squamous and Barrett's oesophagus associated neoplasia or early cancer. A fundamental aspect of endotherapy is removal of the target lesion by endoscopic mucosal resection, or endosopic submucosal dissection. Residual tissue is subsequently ablated to remove the risk of recurrence. The most validated technique for Barrett's oesophagus is radiofrequency ablation, but other techniques such as hybrid-APC and cryotherapy also show good results. This chapter will discuss the evolution of EET, and which patients are most likely to benefit. It will also explore the evidence behind the success of different techniques and provide practical advice on how to carry out the endoscopic techniques with a focus on radiofrequency ablation and endoscopic mucosal resection in particular.

Role of endoscopic therapy in early esophageal cancer

Esophageal carcinoma is a highly lethal cancer associated with high morbidity and mortality. Esophageal squamous cell carcinoma and esophageal adenocarcinoma are the two distinct histological types. There has been significant progress in endoscopic diagnosis and treatment of early stages of cancer using resection and ablation techniques, as shown in several trials in the recent past. Earlier detection of esophageal cancer and advances in treatment modalities have lead to improvement in the 5-year survival from 5% to about 20% in the past decade. Endoscopic eradication therapy is the preferred modality of treatment in cancer limited to mucosal layer of the esophagus as there is very low risk of lymph node metastasis, leading to high cure rates, low risk of recurrence and with few adverse effects. The most common adverse events seen are strictures, bleeding and rarely perforation which can be endoscopically managed. In patients with recurrent advanced disease or invasive tumor, esophagectomy with lymph node dissection remains the mainstay of treatment. There is debate on post-endoscopic surveillance with some studies suggesting closer follow up with upper endoscopy every 6 mo for the first 1-2 years and then annually for the 3 years while others recommending the appropriate action only if symptoms or other abnormalities develop. Overall, the field of endoscopic therapy is still evolving and focus should be placed on careful patient selection using a multidisciplinary approach.

Endoscopic therapy for Barrett’s esophagus and early esophageal cancer: Where do we go from here?

Since Barrett’s esophagus is a precancerous condition, efforts have been made for its eradication by various ablative techniques. Initially, laser ablation was attempted in non-dysplastic Barrett’s esophagus and subsequently, endoscopic ablation using photodynamic therapy was used in Barrett’s patients with high-grade dysplasia who were poor surgical candidates. Since then, various ablative therapies have been developed with radiofrequency ablation having the best quality of evidence. Resection of dysplastic areas only without complete removal of entire Barrett’s segment is associated with high risk of developing metachronous neoplasia. Hence, the current standard of management for Barrett’s esophagus includes endoscopic mucosal resection of visible abnormalities followed by ablation to eradicate remaining Barrett’s epithelium. Although endoscopic therapy cannot address regional lymph node metastases, such nodal involvement is present in only 1% to 2% of patients with intramucosal adenocarcinoma in Barrett esophagus and therefore is useful in intramucosal cancers. Post ablation surveillance is recommended as recurrence of intestinal metaplasia and dysplasia have been reported. This review includes a discussion of the technique, efficacy and complication rate of currently available ablation techniques such as radiofrequency ablation, cryotherapy, argon plasma coagulation and photodynamic therapy as well as endoscopic mucosal resection. A brief discussion of the emerging technique, endoscopic submucosal dissection is also included.

Recent advances in Barrett's esophagus

Barrett's esophagus (BE) is the only known precursor of esophageal adenocarcinoma, one of the few cancers with increasing incidence in developed countries. The pathogenesis of BE is unclear with regard to either the cellular origin of this metaplastic epithelium or the manner in which malignant transformation occurs, although recent data indicate a possible junctional origin of stem cells for BE. Treatment of BE may be achieved using endoscopic eradication therapy; however, there is a lack of discriminatory tools to identify individuals at sufficient risk for cancer development in whom intervention is warranted. Reduction in gastroesophageal reflux of gastric contents including acid is mandatory to achieve remission from BE after endoscopic ablation, and can be achieved using medical or nonmedical interventions. Research topics of greatest interest include the mechanism of BE development and transformation to cancer, risk stratification methods to identify individuals who may benefit from ablation of BE, optimization of eradication therapy, and surveillance methods to ensure that remission is maintained after eradication is achieved.

Controversies in Endoscopic Eradication Therapy for Barrett's Esophagus

Advances in endoscopic eradication therapy for Barrett's Esophagus-associated neoplasia have resulted in a significant paradigm shift in the diagnosis and management of this complex disease. A robust body of literature critically evaluating outcomes of resection and ablative strategies has allowed gastroenterologists to make quality, evidence-based decisions for their patients. Despite this progress, there are still many unanswered questions and challenges that remain. Ultimately, identification of a cost-effective screening modality, biomarkers for risk stratification, and strides to eliminate post surveillance endoscopy after endoscopic eradication therapy are essential to reach our long-term goal for eradication of esophageal adenocarcinoma.