Antireflux surgery followed by bipolar electrocoagulation in the treatment of Barrett's esophagus

Role of endoscopy in early oesophageal cancer

Incidence of oesophageal adenocarcinoma has increased exponentially in the West over the past few decades. Following detection of advanced cancers, 5-year survival rates remain bleak, making identification of early neoplasia, which has a better outcome, important. Detection of subtle oesophageal lesions during endoscopy can be challenging, and advanced imaging techniques might improve their detection. High-definition endoscopy has become a standard in most endoscopy centres, and this technology probably provides better delineation of mucosal features than standard-definition endoscopy. Various image enhancement techniques are now available with the development of new electronics and software systems. Image enhancement with chromoendoscopy using dyes has been a cost-effective option for many years, yet these techniques have been replaced in some contexts by electronic chromoendoscopy, which can be used with the press of a button. However, Lugol's chromoendoscopy remains the gold standard to identify squamous dysplasia. Identification and characterization of subtle neoplastic lesions could help to target biopsies and perform endoscopic resection for better local staging and definitive therapy. In vivo histology with techniques such as confocal endomicroscopy could make endotherapy feasible within a shorter timescale than when relying on histology on tissue samples. Once early neoplasia is identified, treatments include endoscopic resection, endoscopic submucosal dissection or various ablative techniques. Endotherapy has the advantage of being a less invasive technique than oesophagectomy, and is associated with lower mortality and morbidity. Endoscopic ablation therapies have evolved over the past few years, with radiofrequency ablation showing the best results in terms of success rates and complications in Barrett dysplasia.

Management of Barrett's esophagus: From screening to newer treatments

Barrett's esophagus is a premalignant condition of the esophagus in which the squamous epithelium of the lower end of the esophagus is replaced with columnar epithelium. Since the incidence of esophageal adenocarcinoma is on the rise, the major gastroenterology societies have come up with their recommendations for screening and surveillance. Specific factors like obesity, white race, age over 50 years, early age of onset of GERD, smoking and hiatal hernia have been identified as increasing the risk of Barrett's esophagus and adenocarcinoma. The diagnosis requires both endoscopic identification of columnar-lined mucosa and histological confirmation with biopsy. Most medical societies recommend screening people with GERD and other risk factors with endoscopy, but other alternatives employing less invasive methods are currently being studied. Surveillance strategies vary depending on the endoscopic findings and the Seattle biopsy protocol with random 4-quadrant sampling is recommended. Biomarkers have shown promising results, but more studies are needed in the future. White light endoscopy is the standard practice, but other advanced imaging modalities have shown variable results and hence more studies are awaited for further validation. Endoscopic eradication techniques, including both resection and ablation, have shown good but variable results for treating dysplastic lesions confined to the mucosa. Resection procedures to remove visible lesions followed by ablation of the dysplastic mucosa have shown the best results with higher eradication rates and lower recurrence rates. Surgical management is reserved for lesions with sub-mucosal invasion and lymph node spread with increased risk of metastasis.

Endoscopic therapy of Barrett esophagus

Barrett esophagus (BE) is a well-established premalignant condition for esophageal adenocarcinoma (EAC), a lethal cancer with a dismal survival rate. The current guidelines recommend surveillance of patients with BE to detect dysplasia or early cancer before the development of invasive EAC. Recently, endoscopic eradication therapies have been shown to be safe and effective in the treatment of BE-related high-grade dysplasia and early EAC. This article reviews the various treatment options for BE and discusses the current evidence and gaps in knowledge in the understanding of treatment of this condition. In addition, recommendations are provided in context to the recently published guidelines by the American Gastroenterological Association.

Ablation of Barrett's oesophagus: towards improved outcomes for oesophageal cancer?

Barrett's oesophagus is the major risk factor for the development of oesophageal adenocarcinoma. The management of Barrett's oesophagus entails treating reflux symptoms with acid-suppressing medication or surgery (fundoplication). However, neither form of anti-reflux therapy produces predictable regression, or prevents cancer development. Patients with Barrett's oesophagus usually undergo endoscopic surveillance, which aims to identify dysplastic changes or cancer at its earliest stage, when treatment outcomes should be better. Alternative endoscopic interventions are now available and are suggested for the treatment of early cancer and prevention of progression of Barrett's oesophagus to cancer. Such treatments could minimize the risks associated with oesophagectomy. The current status of these interventions is reviewed. Various endoscopic interventions have been described, but with long-term outcomes uncertain, they remain somewhat controversial. Radiofrequency ablation of dysplastic Barrett's oesophagus might reduce the risk of cancer progression, although cancer development has been reported after this treatment. Endoscopic mucosal resection (EMR) allows a 1.5-2 cm diameter piece of oesophageal mucosa to be removed. This provides better pathology for diagnosis and staging, and if the lesion is confined to the mucosa and fully excised, EMR can be curative. The combination of EMR and radiofrequency ablation has been used for multifocal lesions, but long-term outcomes are unknown. The new endoscopic interventions for Barrett's oesophagus and early oesophageal cancer have the potential to improve clinical outcomes, although evidence that confirms superiority over oesphagectomy is limited. Longer-term outcome data and data from larger cohorts are required to confirm the appropriateness of these procedures.

Advances in endoscopic diagnosis and treatment of Barrett's esophagus

Barrett's esophagus (BE) is defined as abnormal specialized columnar metaplasia with intestinalization in place of the normal squamous esophageal epithelium. Gastroesophageal reflux disease is a known risk factor for BE; nonetheless BE is also detected in asymptomatic individuals. Other risk factors for BE include smoking, male gender, age over 50 and obesity. Patients diagnosed with BE (without dysplasia) are recommended to undergo endoscopic surveillance every 3-5 years. Advances in imaging techniques (such as narrow band imaging, autofluorescence imaging and confocal laser endomicroscopy) have the potential to improve the detection of dysplasia and early cancer, thus making surveillance a more cost-effective endeavor. Patients with high grade dysplasia (HGD) and early cancer have a high rate of progression to invasive adenocarcinoma and traditionally these patients were treated with esophagectomy. The rapid advancement of endoscopic therapeutic techniques along with a low risk of complications have made endoscopic therapy an acceptable alternative to an esophagectomy in patients with HGD and early cancer. Several endoscopic treatment techniques such as endoscopic mucosal resection, multipolar electrocoagulation, photodynamic therapy, argon plasma coagulation, cryotherapy, and radiofrequency ablation have been studied for endoscopic treatment.

Endoscopic treatments for Barrett's esophagus: a systematic review of safety and effectiveness compared to esophagectomy

BACKGROUND

Recently, several new endoscopic treatments have been used to treat patients with Barrett's esophagus with high grade dysplasia. This systematic review aimed to determine the safety and effectiveness of these treatments compared with esophagectomy.

METHODS

A comprehensive literature search was undertaken to identify studies of endoscopic treatments for Barrett's esophagus or early stage esophageal cancer. Information from the selected studies was extracted by two independent reviewers. Study quality was assessed and information was tabulated to identify trends or patterns. Results were pooled across studies for each outcome. Safety (occurrence of adverse events) and effectiveness (complete eradication of dysplasia) were compared across different treatments.

RESULTS

The 101 studies that met the selection criteria included 8 endoscopic techniques and esophagectomy; only 12 were comparative studies. The quality of evidence was generally low. Methods and outcomes were inconsistently reported. Protocols, outcomes measured, follow-up times and numbers of treatment sessions varied, making it difficult to calculate pooled estimates.The surgical mortality rate was 1.2%, compared to 0.04% in 2831 patients treated endoscopically (1 death). Adverse events were more severe and frequent with esophagectomy, and included anastomotic leaks (9.4%), wound infections (4.1%) and pulmonary complications (4.1%). Four patients (0.1%) treated endoscopically experienced bleeding requiring transfusions. The stricture rate with esophagectomy (5.3%) was lower than with porfimer sodium photodynamic therapy (18.5%), but higher than aminolevulinic acid (ALA) 60 mg/kg PDT (1.4%). Dysphagia and odynophagia varied in frequency across modalities, with the highest rates reported for multipolar electrocoagulation (MPEC). Photosensitivity, an adverse event that occurs only with photodynamic therapy, was experienced by 26.4% of patients who received porfimer sodium.Some radiofrequency ablation (RFA) or argon plasma coagulation (APC) studies (used in multiple sessions) reported rates of almost 100% for complete eradication of dysplasia. But the study methods and findings were not adequately described. The other studies of endoscopic treatments reported similarly high rates of complete eradication.

CONCLUSIONS

Endoscopic treatments offer safe and effective alternatives to esophagectomy for patients with Barrett's esophagus and high grade dysplasia. Unfortunately, shortcomings in the published studies make it impossible to determine the comparative effectiveness of each of the endoscopic treatments.

Initial experience with new intraluminal devices for GERD, Barrett's esophagus, and obesity

BACKGROUND

Transoral intraluminal surgery is less painful. However, endoscopic antireflux procedures have been unsuccessful, endoscopic foregut mucosal excision procedures are often difficult to perform, and endoscopic intra-luminal suturing is both imprecise and too shallow. We have endeavored to correct these deficiencies and report here new devices for GERD, obesity, and Barrett's mucosal excision.

METHOD

A retrospective review of ex vivo and in vivo animal experiments using sharp blade mucosal excision for esophageal and gastric mucosa and a suturing device with transverse needles designed to full thickness penetrate the gastric wall were completed. A total of 338 excisions were performed in 134 ex vivo tissue experiments and in 119 in vivo attempts. Suture needle testing was performed in ex vivo human stomachs and porcine stomachs and in in vivo canine and baboon stomachs.

RESULTS

One excision perforation (0.9%) occurred in a live animal. Satisfactory mucosal excision depth for the Barrett's device was reproducible. Progressive suture actuation reliability improved from 83% during ex vivo testing to 96.7% in in vivo experiments.

CONCLUSION

The results demonstrate feasibility, reliability, and safety for gastric and esophageal mucosal excision. Suturing reliability improved and further studies will be performed to finalize the instrument designs, the operative techniques, and the other device applications.

Endoluminal therapy for esophageal disease: an introduction

This introductory article summarizes decades of research from many dedicated gastrointestinal endoscopists. It provides a background to Barrett esophagus (BE), exploring the risk of progression to dysplasia and esophageal adenocarcinoma. Two premalignant conditions, BE and colon adenoma, are compared, including their progression to esophageal adenocarcinoma and colon and rectal carcinoma, respectively. A comparison of the risks of surgical treatment and post-surgical complications of these cancers and of the strikingly different paradigms for their prevention is presented. The article concludes with the rationale for endoscopic treatment of Barrett disease.

Endoscopic therapy for Barrett's esophagus

Recent retrospective cohort data and a prospective randomized sham controlled trial have clearly documented the impact of endoscopic ablation therapy on dysplasia and Barrett's esophagus (BE). The clinical indications for ablation of BE includes high-grade dysplasia and intramucosal adenocarcinoma. The techniques of resection of mucosal irregularities and of ablation are reviewed, primarily thermal and photodynamic ablation. Ablation of BE with neoplasia has appropriately entered the clinical arena.

Endoscopic ablation of Barrett's esophagus: a multicenter study with 2.5-year follow-up

BACKGROUND

For patients with Barrett's esophagus (BE), life-long surveillance endoscopy is recommended because of an elevated risk for developing dysplasia and esophageal adenocarcinoma. Various endoscopic therapies have been used to eradicate BE. Recently circumferential radiofrequency ablation has been used with encouraging short-term results.

OBJECTIVE

To provide longer follow-up and to assess the long-term safety and efficacy of step-wise circumferential ablation with the addition of focal ablation for BE.

DESIGN

Prospective, multicenter clinical trial (NCT00489268).

SETTING

Eight U.S. centers, between May 2004 and February 2007.

PATIENTS

Seventy subjects with 2 to 6 cm of BE and histologic evidence of intestinal metaplasia (IM).

INTERVENTIONS

Circumferential ablation was performed at baseline and repeated at 4 months if there was residual IM. Follow-up biopsy specimens were obtained at 1, 3, 6, 12, and 30 months. Specimens were reviewed by a central pathology board. Focal ablation was performed after the 12-month follow-up for histological evidence of IM at the 12-month biopsy (absolute indication) or endoscopic appearance suggestive of columnar-lined esophagus (relative indication). Subjects received esomeprazole for control of esophageal reflux.

MAIN OUTCOME MEASUREMENTS

Complete absence of IM per patient from biopsy specimens obtained at 12 and 30 months, defined as complete remission-IM (CR-IM).

RESULTS

At 12 months, CR-IM was achieved in 48 of 69 available patients (70% per protocol [PP], 69% intention to treat [ITT]). At 30 months after additional focal ablative therapy, CR-IM was achieved in 60 of 61 available patients (98% PP, 97% ITT). There were no strictures or buried glandular mucosa detected by the standardized biopsy protocol at 12 or 30 months, and there were no serious adverse events.

LIMITATIONS

This was an uncontrolled clinical trial with 2.5-year follow-up.

CONCLUSION

Stepwise circumferential and focal ablation resulted in complete eradication of IM in 98% of patients at 2.5-year follow-up.

Randomized trial of argon plasma coagulation versus endoscopic surveillance for barrett esophagus after antireflux surgery: late results

OBJECTIVE

To determine the efficacy of endoscopic argon plasma coagulation (APC) for ablation of Barrett esophagus.

SUMMARY BACKGROUND DATA

APC has been used to ablate Barrett esophagus. However, the long-term outcome of this treatment is unknown. This study reports 5-year results from a randomized trial of APC versus surveillance for Barrett esophagus in patients who had undergone a fundoplication for the treatment of gastroesophageal reflux.

METHODS

Fifty-eight patients with Barrett esophagus were randomized to undergo either ablation using APC or ongoing surveillance. At a mean 68 months after treatment, 40 patients underwent endoscopy follow-up. The efficacy of treatment, durability of the neosquamous re-epithelialization, and safety of the procedure were determined.

RESULTS

Initially, at least 95% ablation of the metaplastic mucosa was achieved in all treated patients. At the 5-year follow-up, 14 of 20 APC patients continued to have at least 95% of their previous Barrett esophagus replaced by neosquamous mucosa, and 8 of these had complete microscopic regression of the Barrett esophagus. Five of the 20 surveillance patients had more than 95% regression of their Barrett esophagus, and 4 of these had complete microscopic regression (1 after subsequent APC treatment). The length of Barrett esophagus shortened significantly in both study groups, although the extent of regression was greater after APC treatment (mean 5.9-0.8 cm vs. 4.6-2.2 cm). Two patients who had undergone APC treatment developed a late esophageal stricture, which required endoscopic dilation, and 2 patients in the surveillance group developed high-grade dysplasia during follow-up.

CONCLUSIONS

Regression of Barrett esophagus after fundoplication is more likely, and greater in extent, in patients who undergo ablation with APC. In most patients treated with APC the neosquamous mucosa remains stable at up to 5-year follow-up. The development of high-grade dysplasia only occurred in patients who were not treated with APC.

Five-year efficacy and safety of photodynamic therapy with Photofrin in Barrett's high-grade dysplasia

BACKGROUND

Barrett's esophagus (BE) with high-grade dysplasia (HGD) is a risk factor for development of esophageal carcinoma. Photodynamic therapy (PDT) with Photofrin (PHO) has been used to eliminate HGD in BE.

OBJECTIVE

Our purpose was to compare PHOPDT plus omeprazole with omeprazole only (OM).

DESIGN

Five-year follow-up of a randomized, multicenter, multinational, pathology-blinded HGD trial.

SETTING

30 sites in 4 countries.

PATIENTS

208.

INTERVENTIONS

Patients with BE and HGD were randomized (2:1) to PHOPDT (n=138) or OM (n=70) into a 2-year trial followed up for 3 more years. PHOPDT patients received 2 mg/kg PHO intravenously followed by endoscopic laser light exposure of Barrett's mucosa at a wavelength of 630 nm within 40 to 50 hours to a maximum of 3 courses at least 90 days apart. Both groups received 20 mg of OM twice daily. Pathologists at one center assessed biopsy specimens in a blinded fashion.

MAIN OUTCOME MEASUREMENT

HGD ablation status over 5 years of follow-up.

RESULTS

At 5 years PHOPDT was significantly more effective than OM in eliminating HGD (77% [106/138] vs 39% [27/70], P<.0001). A secondary outcome measure preventing progression to cancer showed a significant difference (P=.027) with about half the likelihood of cancer occurring in PHOPDT (21/138 [15%]) compared with OM (20/70 [29%]), with a significantly (P=.004) longer time to progression to cancer favoring PHOPDT.

LIMITATIONS

Not all patients were available for follow-up.

CONCLUSIONS

This 5-year randomized trial of BE patients with HGD demonstrates that PHOPDT is a clinically and statistically effective therapy in producing long-term ablation of HGD and reducing the potential impact of cancer compared with OM.

Endoscopic therapy of dysplasia and early-stage cancers of the esophagus

Endoscopic treatments have become a viable alternative for some patients with early-stage esophageal neoplasia. Although esophagectomy remains the standard of care for high-grade dysplasia and superficial cancers, surgical morbidity and mortality may deter patients who are medically unfit or reluctant to undergo surgery. Photodynamic therapy (PDT) and endoscopic mucosal resection (EMR) are the best-studied nonsurgical approaches at present. PDT has been reported to eradicate high-grade dysplasia (HGD) and early Barrett's cancers at rates ranging from 75% to 100% and 17% to 100%, respectively, and a recent randomized controlled trial confirmed that PDT may prevent progression of HGD to cancer. Complete remission rates greater than 90% have also been reported with EMR and other mucosa-ablating interventions, although recurrence rates necessitate close endoscopic surveillance and retreatment in some patients. In addition to PDT and EMR, several emerging endoscopic treatment options for superficial esophageal neoplasia may provide attractive alternatives to surgery.

Balloon-based, circumferential, endoscopic radiofrequency ablation of Barrett's esophagus: 1-year follow-up of 100 patients

OBJECTIVE

To assess the dose-response, safety, and efficacy of circumferential endoscopic ablation of Barrett's esophagus (BE) by using an endoscopic balloon-based ablation device (HALO360 System).

DESIGN

This study was conducted in 2 serial phases (dosimetry phase and effectiveness phase) to evaluate a balloon-based ablation device that delivers a pre-set amount of energy density (J/cm2) to BE tissue. The dosimetry phase evaluated the dose-response and the safety of delivering 6 to 12 J/cm2. The effectiveness phase used 10 J/cm2 (delivered twice [x2]) for all patients, followed by EGD with biopsies at 1, 3, 6, and 12 months. A second ablation procedure was performed if BE was present at 1 or 3 months. Patients received esomeprazole 40 mg twice a day for 1 month after ablation, and 40 mg every day thereafter. Postablation symptoms were quantified by using a 14-day symptom diary (scale, 0-100). A complete response (CR) was defined as all biopsy specimens negative for BE at 12 months.

SETTING

Eight U.S. centers, between September 2003 and September 2005.

PATIENTS

Patients were 18 to 75 years of age, with a diagnosis of BE (without dysplasia), with histopathology reconfirmation of the diagnosis within 6 months of enrollment.

RESULTS

In the dosimetry phase, 32 patients (29 men; mean age, 56.8 years) were enrolled. Median symptom scores returned to a score of 0 of 100 by day 3. There were no dose-related serious adverse events, and the outcomes at 1 and 3 months permitted the selection of 10 J/cm2 (x2) for the subsequent effectiveness phase of the study. In the effectiveness phase, 70 patients (52 men, 18 women; mean age, 55.7 years) were enrolled. Median symptom scores returned to a score of 0 of 100 by day 4. At 12 months (n = 69; mean, 1.5 sessions), a CR for BE was achieved in 70% of patients. There were no strictures and no buried glandular mucosa in either study phase (4306 biopsy fragments evaluated).

CONCLUSIONS

Circumferential ablation of nondysplastic BE by using this balloon-based ablation device can be performed with no subsequent strictures or buried glands and with complete elimination of BE in 70% of patients at 1-year follow-up.

Endoluminal therapy for Barrett's esophagus

This article reviews methods to minimize the complications associated with endoscopic therapy for patients with Barrett's esophagus. To place this discussion in context, the natural history of Barrett's esophagus and the risks associated with progression to dysplasia and invasive carcinoma are reviewed. Operative esophageal resection traditionally is recommended for patients with Barrett's high-grade dysplasia and early carcinoma, and these surgical risks also are reviewed. Finally, all currently approved and commercially available methods for endoscopic ablation and resection of Barrett's disease are categorized according to their application methods of ablation: focal ablation, field ablation, and mucosal resection. The clinical experience with these devices is reviewed with their associated adverse events and complications. Caveats, concerns, and recommendations are discussed to help minimize the complications associated with the use of these important technologies that hold the promise of removing or destroying Barrett's disease to prevent the development of invasive carcinoma.

Photodynamic therapy with porfimer sodium for ablation of high-grade dysplasia in Barrett's esophagus: international, partially blinded, randomized phase III trial

BACKGROUND

Barrett's esophagus (BE) may lead to high-grade dysplasia (HGD) and adenocarcinoma. The objective was to examine the impact of treating patients with BE and with HGD by using porfimer sodium (POR) and photodynamic therapy (PDT) for ablating HGD and reducing the incidence of esophageal adenocarcinoma.

METHODS

The design was a multicenter, partially blinded (pathology), randomized clinical trial conducted in patients with BE who have HGD. There were 30 contributing centers. A total of 485 patients were screened, with 208 in the intent-to-treat population and 202 in the safety population. Patients were randomized on a 2:1 basis to compare PDT with POR plus omeprazole (PORPDT) with omeprazole only (OM). The main outcome measurement was complete HGD ablation occurring at any time during the study period.

RESULTS

There was a significant difference (p < 0.0001) in favor of PORPDT (106/138 [77%]) compared with OM (27/70 [39%]) in complete ablation of HGD at any time during the study period. The occurrence of adenocarcinoma in the PORPDT group (13%) (n=18) was significantly lower (p < 0.006) compared with the OM group (28%) [corrected] (n=20). The safety profile showed 94% of patients in the PORPDT group and 13% of patients in the OM group had treatment-related adverse effects. The limitations of the study were that PDT therapy may have had to be applied more than once and that patients spent more time in treatment. The patients and the physicians were not blinded to the treatment.

CONCLUSIONS

PORPDT in conjunction with omeprazole is an effective therapy for ablating HGD in patients with BE and in reducing the incidence of esophageal adenocarcinoma.

Preliminary findings from tests of a microwave applicator designed to treat Barrett's oesophagus

Barrett's oesophagus is considered to increase the risk of cancer 30-fold. Helical microwave antennas have been developed for ablative treatment of Barrett's. A microwave balloon applicator was tested in an initial animal study using adult white pigs. For treatment, a balloon filled with tissue-equivalent material encapsulated the antenna. A range of different treatment temperatures and durations was used to investigate a range of thermal ablations of the oesophageal epithelium. Eight animals were investigated, five non-survival and three with a 1-week survival period. The balloon was fitted with an array of temperature sensors, which gave an indication of the treatment in situ and allowed modifications to be performed in real time. Temperature data were recorded from all four quadrants of the balloon throughout and test sites were collected and analysed histologically. All experiments were successfully completed without perforation, serious adverse effects or death. Sites of discrete ulceration were induced in the survival tests, whereas the non-survival tests yielded little reproducible tissue modification. Results suggested that an activation temperature of approximately 55 degrees C needed to be reached during the treatment for tissue damage to be induced. Once damage had been triggered the severity was related to the mean temperature attained during the treatment period. A mean temperature of 52 degrees C or more resulted in substantial damage, whilst a mean temperature of approximately 50 degrees C resulted in the desired surface damage with sparing of subjacent tissues.

Endoscopic therapy for Barrett's esophagus

With the increase in the rate of esophageal adenocarcinoma in the United States and the Western world matched with the high morbidity and mortality of esophagectomy, there is an increasing need for new and effective techniques to treat and prevent esophageal adenocarcinoma. A wide variety of endoscopic mucosal ablative techniques have been developed for early esophageal neoplasia. However, long-term control of neoplasic risk has not been demonstrated. Most studies show that specialized intestinal metaplasia may persist underneath neo-squamous mucosa, posing a risk for subsequent neoplastic progression. In this article we review current published literature on endoscopic therapies for the management of Barrett's esophagus.

Technology Insight: ablative techniques for Barrett's esophagus—current and emerging trends

New mucosal ablative techniques that can be used in the esophagus have emerged over the past two decades. These techniques have been developed primarily to treat the precursors of esophageal adenocarcinoma: dysplasia in Barrett's esophagus and early esophageal cancer. Although high-grade dysplasia and early stage cancer can be treated with esophagectomy, the inherent morbidity and mortality of esophageal adenocarcinoma and the morbidities, difficulties, costs and limitations of the current technology mean that there has been a significant increase in interest and research regarding alternative treatments such as ablative techniques. At this stage it is not clear which of the numerous endoscopic ablative techniques available-photodynamic therapy, laser therapy, multipolar electrocoagulation, argon plasma coagulation, endoscopic mucosal resection, radiofrequency ablation or cryotherapy-will emerge as superior. In addition, it has yet to be determined whether the risks associated with ablation therapy are less than the risk of Barrett's esophagus progressing to cancer. Whether ablation therapy eliminates or significantly reduces the risk of cancer, eliminates the need for surveillance endoscopy, or is cost-effective, also remains to be seen. Comparative trials that are now underway should help to answer these questions.

Effect of insertion depth on helical antenna performance in a muscle-equivalent phantom

Barrett's oesophagus is considered to increase the risk of cancer 30 fold. A set of helical microwave antennas was designed to investigate their potential use in the thermal therapy of Barrett's oesophagus. For treatment, a balloon filled with muscle-equivalent material encapsulates the antenna. The effects of insertion depth and coil-spacing on the thermal distribution produced by the antennas (20-35 mm) were characterized. The 35 mm helical antenna, with a coil-spacing of 3.6 mm resulted in uniform heating for an insertion depth of 40 mm. It was observed that the resultant temperature distribution produced, by the antennas, was dependent on the insertion depth within the phantom. For all antennas studied, deeper insertion resulted in two high intensity regions, approximately 1/4 and 3/4 along the antenna length. In contrast, shallow insertion resulted in predominant tip heating with undesirable heating at the phantom entry point. However, by manipulating the coil-spacing of the helix, uniform temperature profiles were achieved for a range of insertion depths.

Randomized trial of argon plasma coagulation vs. multipolar electrocoagulation for ablation of Barrett's esophagus

BACKGROUND

Endoscopic ablation of Barrett's esophagus has been described in which various thermocoagulation modalities are used in combination with a high dose of a proton pump inhibitor. No randomized comparison of ablation strategies has been published.

METHODS

Referred patients were screened to identify those with Barrett's esophagus 2 to 7 cm in length, without high-grade dysplasia or cancer. Included patients received pantoprazole (40 mg twice a day), followed by randomization to treatment with argon plasma coagulation (APC) or multipolar electrocoagulation (MPEC). The primary outcome measure was the number of treatment sessions required for endoscopic ablation.

RESULTS

Of 235 patients screened, 52 were randomized. The mean length of Barrett's esophagus was 3.1 cm in the MPEC group vs. 4.0 cm in the APC group (p = 0.03). Otherwise, the treatment groups were similar with regard to baseline characteristics. The mean number of treatment sessions required for endoscopic ablation was 2.9 for MPEC vs. 3.8 for APC (p = 0.04) in an intention-to-treat analysis (p = 0.249, after adjustment for the difference in length of Barrett's esophagus). The proportion of patients in which ablation was endoscopically achieved proximal to the gastroesophageal junction was 88% for the MPEC group vs. 81% for the APC group (p = 0.68) and histologically achieved in 81% for MPEC vs. 65% for APC (p = 0.21). The mean time required for the first treatment session was 6 minutes with MPEC vs. 10 minutes with APC (p = 0.01) in per protocol analysis. There was no serious adverse event, but transient moderate to severe upper-GI symptoms occurred after MPEC in 8% vs. 13% after APC (p = 0.64). Conclusions Although there were no statistically significant differences, ablation of Barrett's esophagus with pantoprazole and MPEC required numerically fewer treatment sessions, and endoscopic and histologic ablation was achieved in a greater proportion of patients compared with treatment with pantoprazole and APC.

An animal model study to clarify and investigate endoscopic tissue coagulation by using a new monopolar device

BACKGROUND

The purpose of this study was to evaluate a new device for endoscopic monopolar electrocoagulation and to develop ablative techniques by using this new device.

METHODS

The new device consists of an overtube with a wire mesh electrode in an oval opening in the distal end and a balloon at the distal end. High-frequency electrical current was applied in 5 animal (swine) esophagi by using this specially designed monopolar electrocoagulation device. A total of 32 "lesions" were ablated by using blend electrosurgical waveforms for different time durations. The esophagi were then resected for histopathologic evaluation.

RESULTS

Histopathologic study of the ablated lesions demonstrated that, by using the monopolar electrocoagulation device, different levels of degeneration of the mucosa and submucosa were achieved. The method for use of the device is fast and easy to apply.

CONCLUSIONS

The ablative procedure with the new overtube device is minimally invasive, clearly feasible, and easy to apply. This new device potentially can be used in patients for tissue ablation.

Prevention of adenocarcinoma by reversing Barrett's esophagus with mucosal ablation

The ultimate goal of therapy in patients with Barrett's esophagus (BE) is to reduce the risk of developing adenocarcinoma of the esophagus. Neither pharmacologic nor surgical therapy has been documented to reduce this risk. There is preliminary evidence that many forms of mucosal ablation combined with acid reduction therapy result in restitution of normal squamous epithelium in patients with BE. Acid reduction can be accomplished with high-dose proton pump inhibitor therapy or antireflux surgery. Endoscopic ablation can be accomplished with photodynamic therapy, laser, multipolar electrocoagulation, a heater probe, and argon plasma coagulation. These techniques require further study so the complication rates can be compared. The success of reversing BE must be evaluated in a standard way utilizing large-capacity biopsy forceps through a therapeutic endoscope. Ideally, patients at high risk of developing adenocarcinoma of the esophagus can be treated with ablation therapy and followed to document a reduction in the development of adenocarcinoma of the esophagus. A validated biomarker would help select high risk patients appropriate for reversal therapy. Currently, patients who are at prohibitive risk for surgery or who refuse surgery are candidates for combination therapy including mucosal ablation to reverse their BE. This therapy offers the promise of less morbidity and greater quality of life than resection.

Multipolar electrocoagulation

Multipolar electrocoagulation (MPEC) is a readily available technique that can be applied for endoscopic ablation of Barrett's esophagus. MPEC, in combination with high dose proton pump inhibitor therapy or antireflux surgery, results in normal squamous epithelium in most patients without major adverse effects. The ultimate clinical role of MPEC has not been determined but may be adjunctive to other techniques in appropriately selected patients at high risk for neoplastic progression.

Antireflux surgery for Barrett's oesophagus

Barrett's oesophagus is usually the result of severe reflux disease. Relief of reflux symptoms is the primary aim of treatment in patients with Barrett's oesophagus who do not have high-grade dysplasia. Some studies with medium-term (2-5 years) follow up show that antireflux surgery can provide good or excellent symptom control, with normal oesophageal acid exposure, in more than 90% of patients with Barrett's oesophagus. Antireflux surgery, but not medical therapy, can also reduce duodenal nonacid reflux to normal levels. There is no conclusive evidence that antireflux surgery can prevent the development of dysplasia or cancer, or that it can reliably induce regression of dysplasia, and patients with Barrett's oesophagus should therefore remain in a surveillance programme after operation. Some data suggest that antireflux surgery can prevent the development of intestinal metaplasia (IM) in patients with reflux disease but no IM. The combination of antireflux surgery plus an endoscopic ablation procedure is a promising treatment for patients with Barrett's oesophagus with low-grade dysplasia.

Screening for esophageal adenocarcinoma: an evidence-based approach

Adenocarcinoma of the esophagus and the gastroesophageal junction is the twentieth most common malignancy in the United States. In developed countries, the incidence of esophageal adenocarcinoma is increasing 5% to 10% per year. Despite the use of endoscopy for earlier detection, mortality from esophageal adenocarcinoma has not declined. Using an evidence-based approach, we review screening methods for esophageal adenocarcinoma, including the use of a symptom questionnaire, identification of patients with a family history of Barrett's esophagus, peroral or transnasal endoscopy, barium swallow, fecal occult blood testing, and brush and balloon cytology. Screening has not been shown to reduce rate of progression of Barrett's esophagus to esophageal cancer. Many treatment options for dysplastic Barrett's esophagus or early carcinoma appear effective, but long-term follow-up data are not available. There is currently insufficient evidence supporting population-based screening for Barrett's esophagus. Several risk factors, including severe reflux symptoms, male sex, and obesity, may identify patients with gastroesophageal reflux disease who are at the greatest risk of the development of cancer.

Mucosal ablation in Barrett's esophagus

Barrett's esophagus is a prevalent, premalignant condition affecting the gastroesophageal junction and distal esophagus. Ablation plus antireflux therapy has recently been advocated to prevent the development of adenocarcinoma or to treat those unfit or unwilling to undergo esophagectomy. The present article, based on a search of Medline/ISI databases and cross-referencing of relevant articles, reviews the literature on this subject. A number of techniques have been used to remove the affected mucosa, including laser, electrocoagulation, argon plasma coagulation and photodynamic therapy but, as yet, none has been shown to be superior. Depending on the method used, ablation results in complete removal of Barrett's esophagus in approximately one third of patients and a partial response in nearly two-thirds. The resultant squamous mucosa is apparently 'normal' but may regress. To promote and maintain regeneration, antireflux therapy must be sufficient to reduce repetitive injury to the esophageal mucosa. Whether ablation reduces the cancer risk or delays its occurrence is unknown, though recent data suggests benefit. Complications are infrequent and usually mild. Regular follow-up endoscopy and deep biopsies continue to be necessary. Careful data from much larger populations with long-term follow-up is required before ablation reaches the stage of broad clinical application.

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

The incidence of adenocarcinoma of the esophagus has increased dramatically over recent years. Because Barrett's epithelium is recognized as a risk factor for adenocarcinoma there is an interest in reversing this metaplasia. A number of endoscopic methods of destruction of esophageal columnar epithelium have been described. The purpose of this article is to review the currently available methods of managing Barrett's epithelium with particular reference to the role of ablative therapy in reducing the risk of adenocarcinoma.

Barrett's esophagus

Barrett's esophagus is an acquired condition resulting from severe esophageal mucosal injury. It still remains unclear why some patients with gastroesophageal reflux disease develop Barrett's esophagus whereas others do not. The diagnosis of Barrett's esophagus is established if the squamocolumnar junction is displaced proximal to the gastroesophageal junction and if intestinal metaplasia is detected by biopsy. Despite this seemingly simple definition, diagnostic inconsistencies remain a problem, especially in distinguishing short segment Barrett's esophagus from intestinal metaplasia of the gastric cardia. Barrett's esophagus would be of little importance were it not for its well-recognized association with adenocarcinoma of the esophagus. The incidence of esophageal adenocarcinoma continues to increase and the 5-year survival rate for this cancer remains dismal. However, cancer risk for a given patient with Barrett's esophagus is lower than previously estimated. Current strategies for improved survival in patients with esophageal adenocarcinoma focus on cancer detection at an early and potentially curable stage. This can be accomplished either by screening more patients for Barrett's esophagus or with endoscopic surveillance of patients with known Barrett's esophagus. Current screening and surveillance strategies are inherently expensive and inefficient. New techniques to improve the efficiency of cancer surveillance are evolving rapidly and hold the promise to change clinical practice in the future. Treatment options include aggressive acid suppression, antireflux surgery, chemoprevention, and ablation therapy, but there is still no clear consensus on the optimal treatment for these patients.

Role of mucosal ablative therapy in the treatment of the columnar-lined esophagus

With the high prevalence of gastroesophageal reflux-like symptoms in the United States and the association between GERD symptoms and the premalignant condition of BE, there is more and more demand for new and efficacious techniques to treat BE. A wide variety of endoscopic mucosal ablative techniques have been developed with promising initial results. Long-term control of neoplastic risk, however, has not been demonstrated, and most studies demonstrate that there is still potentially some intestinal mucosa present underneath squamous mucosa. Currently, more study is needed to determine which patient groups require therapy of any kind and to determine which therapies would be the most efficacious. Genetic markers may aid in identification of subgroups that are at risk for cancer and help to identify those who would respond to mucosal therapy. Even in patients who have HGD, subgroups of patients who have focal HGD have been found to have better prognosis than those who have more widespread HGD. Currently, there is sufficient information to consider mucosal ablative techniques in patients who are not good surgical candidates. Photodynamic therapy, APC, KTP, Nd:YAG and argon lasers, MPEC, and EMR may provide good alternatives, depending on the degree of dysplasia, the extent of disease, and the age of the patient. Photodynamic therapy and Nd:YAG laser therapy have been applied to more neoplastic lesions, whereas KTP:YAG, APC, and multipolar coagulation have been successful in nondysplastic Barrett's mucosa. In the future, there will be more information to justify the application of mucosal ablative therapy in selected patients.

Effective and safe endoscopic reversal of nondysplastic Barrett's esophagus with thermal electrocoagulation combined with high-dose acid inhibition: a multicenter study

BACKGROUND

Barrett's esophagus is a metaplastic change in the esophageal lining with an increased risk for adenocarcinoma. Multiple endoscopic techniques have been applied in an effort to reverse Barrett's. This is a multicenter trial defining the efficacy and safety of multipolar electrocoagulation combined with high-dose acid inhibition.

METHODS

Patients with a 2- to 6-cm segment of Barrett's esophagus without dysplasia were enrolled at 3 centers. They were treated with omeprazole 40 mg twice daily and then with up to 6 sessions with electrocoagulation aimed at eliminating all the endoscopically apparent Barrett's. Four quadrant large-capacity biopsies every 2 cm were centrally assessed for residual intestinal metaplasia.

RESULTS

Fifty-eight patients reached the endpoint of failure of visual reversal of Barrett's after 6 treatment sessions or a 6-month follow-up after the last session. Eighty-five percent had visual reversal and 78% both visual and histologic reversal. Four patients had histologic evidence of residual intestinal metaplasia. Transient esophageal symptoms were common. One patient developed a stricture requiring dilation and one required overnight hospitalization for chest pain.

CONCLUSIONS

The majority of patients with 2 to 6 cm of nondysplastic Barrett's esophagus can be safely reversed with this combination therapy. Long-term follow-up will be necessary to document the durability of the new squamous epithelium.

Management of Barrett's oesophagus, dysplasia and early adenocarcinoma

There has been a dramatic increase in recent years in the incidence of Barrett's oesophagus and the oesophageal adenocarcinoma associated with it. Adequate monitoring strategies and improved diagnostic procedures are therefore essential. Alongside conventional video-endoscopy with four-quadrant biopsies, many additional diagnostic procedures are now available to improve monitoring. These allow the early diagnosis of dysplastic areas and early carcinomas. Both thermal procedures (argon plasma coagulation, multipolar electrocoagulation and KTP laser and Nd&ratio;YAG laser treatment) and non-thermal ablation procedures (photodynamic therapy) are used for the endoscopic ablation of Barrett's mucosa without dysplasia, being employed in addition to acid suppression treatment. On the basis of the data currently available, it is, however, not yet possible to offer a general recommendation in favour of endoscopic ablation. Alongside surgical treatment for high-grade dysplasia and early carcinoma, endoscopic treatment procedures, which have a much lower complication and mortality rate, will probably play an important role in the future. Endoscopic mucosal resection and photodynamic therapy are particularly promising. Long-term results with these procedures are, however, still awaited.

New treatment for Barrett's oesophagus

Barrett's esophagus is characterised by the presence of specialised intestinal metaplasia in the lower esophagus. Its importance is related primarily to its link with adenocarcinoma of the lower esophagus, often preceded by dysplastic changes. The incidence of this carcinoma has increased dramatically over the last few decades. Although modern treatments, particularly acid suppression with proton pump inhibitors, have been most useful in controlling the reflux symptoms associated with Barrett's esophagus, they have not reduced the incidence of adenocarcinoma of the esophagus. The same can be said about anti-reflux surgery. Surgical excision of Barrett's esophagus has been advocated when high-grade dysplasia is detected; this carries considerable morbidity and mortality, so alternative treatments are being developed. This update summarises recent information concerning newer treatments aimed at eradicating Barrett's esophagus. These vary from thermal coagulation (using electrocoagulation and heater probes) to lasers, photodynamic therapy and mechanical methods. Of these, photodynamic therapy using a porphyrin precursor (5-amino-laevulinic acid) seems to give the most consistent satisfactory results with a minimum of complications. However, persistence of some metaplastic cells beneath the neo-squamous layer remains a problem. Ongoing effective acid control (by medical or surgical therapy) is also essential to prevent recurrence of Barrett's esophagus. Future research is aimed at perfecting these methods. Ultimately, it may be possible to understand the molecular biology which could help to predict which patients are at greatest risk of developing dysplastic and carcinomatous changes.

Gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common chronic disorder affecting millions of people worldwide. This is a review of a number of published studies in the past year that increase current understanding or raise important issues about this disorder. Among the areas covered are the epidemiology and role of genetics in GERD; its pathogenesis with respect to duodenogastric reflux and impaired epithelial barrier function; the effects of atropine on transient lower esophageal sphincter relaxations; the role of acid suppression, heat shock proteins, and the enzyme cyclooxygenase-2 in Barrett esophagus and esophageal adenocarcinoma; the complication rates in laparoscopic fundoplication; and the results of ablation therapy for the treatment of Barrett esophagus and esophageal adenocarcinoma. These investigations reinforce a sense of the complexity of GERD and provide optimism that modern technology will continue to be used to develop more effective treatments.

High power setting argon plasma coagulation for the eradication of Barrett's esophagus

OBJECTIVE

The term Barrett's esophagus refers to a premalignant condition that is characterized by the replacement of the esophageal squamous mucosa by a columnar-lined one. Preliminary studies have demonstrated reversal of Barrett's mucosa after endoscopic coagulation with different techniques associated with acid inhibition. However, most of these studies have shown that residual Barrett's glands are found underneath the new squamous epithelium in up to 40% of patients. The goal of our study is to verify whether complete restoration of Barrett's mucosa can be achieved by the combination of high power setting argon plasma coagulation and omeprazole.

METHODS

A total of 33 patients (mean age: 55.2 yr, range: 21-84 yr; 21 men and 12 women) with histologically demonstrated Barrett's esophagus (mean length: 4.05 cm, range: 0.5-7 cm) were treated. Fourteen cases presented with low-grade dysplasia and one with high-grade dysplasia. All of the extent, or until a maximum of 4 cm, of the Barrett's mucosa was cauterized in each session using argon beam coagulation at a power setting of 65-70 W. All patients received 60 mg omeprazole during the treatment period.

RESULTS

Complete restoration of squamous mucosa was obtained in all 33 cases after a mean of 1.96 sessions (range, 1-4). Endoscopic results were histologically confirmed. Nineteen (57.5%) patients experienced moderate to severe chest pain and odyno-dysphagia lasting for 3-10 days after the procedure. Five of these cases experienced high fever and a small volume of pleural effusion, and three patients developed esophageal strictures that needed to be dilated. Another patient developed pneumomediastinum and subcutaneous emphysema without evidences of perforation. After a mean follow-up of 10.6 months there was one endoscopic, as well as histological, recurrence of Barrett's mucosa in a patient with an ineffective laparoscopic fundoplication.

CONCLUSIONS

High power setting argon plasma coagulation combined with intensive acid suppression is an effective treatment for the total endoscopic ablation of Barrett's esophagus, at least in the short term. Long-term follow-up of treated patients in whom gastroesophageal reflux is surgically or medically alleviated seems mandatory before drawing definitive conclusions about this therapy.

Barrett esophagus

Barrett esophagus continues to intrigue investigators and clinicians alike as the new millennium begins. A large number of publications in the past year have discussed issues of epidemiology, prevalence, detection, and treatment of Barrett esophagus. Chronic symptoms of gastroesophageal reflux were identified as a strong risk for esophageal adenocarcinoma. The relative frequency of short and long Barrett and cardia intestinal metaplasia in patients who undergo upper endoscopy have been better defined. Biomarkers in patients with Barrett may eventually be helpful in identifying those at high risk for the development of neoplasia. High-dose proton pump inhibition to the point of near elimination of esophageal acid exposure remains disappointing in its impact on the surface area of Barrett. Finally, the developments in endoscopic therapy for patients with Barrett esophagus continue to be promising.