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

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.

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.

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.

State of the art in nonthermal plasma processing for biomedical applications: Can it help fight viral pandemics like COVID-19?

Plasma processing finds widespread biomedical applications, such as the design of biosensors, antibiofouling surfaces, controlled drug delivery systems, and in plasma sterilizers. In the present coronavirus disease (COVID-19) situation, the prospect of applying plasma processes like surface activation, plasma grafting, plasma-enhanced chemical vapor deposition/plasma polymerization, surface etching, plasma immersion ion implantation, crosslinking, and plasma decontamination to provide timely solutions in the form of better antiviral alternatives, practical diagnostic tools, and reusable personal protective equipment is worth exploring. Herein, the role of nonthermal plasmas and their contributions toward healthcare are timely reviewed to engage different communities in assisting healthcare associates and clinicians, not only to combat the current COVID-19 pandemic but also to prevent similar kinds of future outbreaks.

Therapeutic Upper Gastrointestinal Endoscopy in Pediatric Gastroenterology

This paper seeks to give a broad overview of pediatric upper gastrointestinal (GI) pathologies that we are now able to treat endoscopically, acquired or congenital, and we hope this delivers the reader an impression of what is increasingly available to pediatric endoscopists and their patients.

Volumetric laser endomicroscopy and its application to Barrett's esophagus: results from a 1,000 patient registry

Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291.

Endoscopic management of esophageal cancer

Esophageal cancer (EC) generally consists of squamous cell carcinoma (which arise from squamous epithelium) and adenocarcinoma (which arise from columnar epithelium). Due to the increased recognition of risk factors associated with EC and the development of screening programs, there has been an increase in the diagnosis of early EC. Early EC is amenable to curative therapy by endoscopy, which can be performed by either endoscopic resection or endoscopic ablation. Endoscopic resection consists of either endoscopic mucosal resection (preferred in cases of adenocarcinoma) or endoscopic submucosal dissection (preferred in cases of squamous cell carcinoma). Endoscopic ablation can be performed by either radiofrequency ablation, cryotherapy, argon plasma coagulation or photodynamic therapy, amongst others. Endoscopy can also assist in the management of complications post-esophageal surgery, such as anastomotic leaks and perforations. Finally, there is a growing role for endoscopy to manage end-of-life palliative symptoms, especially dysphagia. The growing use of esophageal stents, debulking therapy and dilation can assist in improving a patient’s quality of life. In this review, we examine the multiple roles of endoscopy in the management of patients with EC.

Prospective study of endoscopic focal cryoballoon ablation for esophageal squamous cell neoplasia in China

BACKGROUND AND AIMS

Esophageal squamous cell neoplasia (ESCN) has a significant risk for progression to cancer. Current treatment options, endoscopic mucosal resection (EMR) or submucosal dissection (ESD), have their limitations. The cryoballoon focal ablation system (CbFAS) is a novel endoscopic ablation therapy device. We aimed to assess the safety, tolerability, and efficacy of CbFAS for eradication of ESCN.

METHODS

In this single-center prospective trial in China, patients with 1 flat unstained lesion (USL) on Lugol chromoendoscopy that contained moderate- or high-grade intraepithelial neoplasia (MGIN or HGIN, respectively) were enrolled. CbFAS was performed using side-by-side applications of 10 seconds, treatment was repeated at 3-month intervals until a complete response (CR) was established. The response at 12 months was the primary trial endpoint. Safety phone calls were performed at 2, 7, and 30 days after the initial CbFAS.

RESULTS

We enrolled 80 patients (59 MGIN, 21 HGIN) with a median USL length of 3 cm (interquartile range [IQR], 3-4). Seventy-nine received treatment, with a median of 5 side-by-side applications (IQR, 4-7) per patient over a median of 8 minutes (IQR, 5-10). After a single treatment, 70 of 78 patients (90%) exhibited CR, and 1 was lost to follow-up. The other 8 with persisting USLs were retreated, and all achieved CR after this second treatment. At 12 months after the initial CbFAS, 76 of 78 patients (97%) exhibited CR and 2 (3%) had recurrent MGIN. No strictures or serious adverse events occurred. Four patients developed self-limiting mucosal lacerations on balloon inflation. The postprocedure median pain score was 1 of 10 (IQR, 0-2) at day 2 and 0 (0-0) at days 7 and 30.

CONCLUSIONS

The results suggest that the CbFAS is safe, well tolerated, and effective in inducing endoscopic and histologic remission in patients with ESCN of limited size. (Clinical trial registration number: NCT02605759.).

Efficacy of low-temperature plasma-activated gas disinfection against biofilm on contaminated GI endoscope channels

BACKGROUND AND AIMS

It has been increasingly recognized that the safety of GI endoscopes needs to be improved by addressing the small margin of safety of high-level disinfectants (HLDs) and the failure of HLDs to clear multidrug-resistant organisms and biofilms. There is also an unmet need for effective low-temperature sterilization techniques that have a clear pathway for U.S. Food and Drug Administration clearance. Here, we report the results of our investigation of a novel argon plasma-activated gas (PAG) for disinfection and potentially sterilization of biofilm-contaminated endoscopic channels.

METHODS

Test polytetrafluoroethylene channel segments were contaminated with 4-, 24- and 48-hour luminal biofilms of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, or Escherichia coli and were treated by PAG flowing for up to 9 minutes. After PAG treatment, inactivation and dispersal of luminal bacterial biofilms and their regrowth in 48 hours were evaluated. Reactive species induced by PAG were measured with colorimetric probes and electron spin resonance spectrometry. Surface morphology and elemental composition of PAG-treated channel material were analyzed with scanning electron microscopy.

RESULTS

PAG treatment for 9 minutes led to more than 8 log reduction of viable cells and dispersal of 24- and 48-hour luminal biofilms of all 3 bacteria and to suppression of their regrowth, whereas it resulted in little morphologic abnormalities in channel material. Ozone concentration of PAG fell to below .01 ppm within 30 seconds of switching off the plasma. PAG-treated deionized water was acidified with numerous types of reactive species, each with a concentration some 3 orders of magnitude or more below its bacterial inhibition concentration.

CONCLUSIONS

PAG is capable of effectively and rapidly disinfecting luminal bacterial biofilms and offers an alternative to the step of HLDs and/or ethylene oxide in the endoscope reprocessing procedure with safety to personnel and environment.

Improved Wound Healing of Airway Epithelial Cells Is Mediated by Cold Atmospheric Plasma: A Time Course-Related Proteome Analysis

The promising potential of cold atmospheric plasma (CAP) treatment as a new therapeutic option in the field of medicine, particularly in Otorhinolaryngology and Respiratory medicine, demands primarily the assessment of potential risks and the prevention of any direct and future cell damages. Consequently, the application of a special intensity of CAP that is well tolerated by cells and tissues is of particular interest. Although improvement of wound healing by CAP treatment has been described, the underlying mechanisms and the molecular influences on human tissues are so far only partially characterized. In this study, human S9 bronchial epithelial cells were treated with cold plasma of atmospheric pressure plasma jet that was previously proven to accelerate the wound healing in a clinically relevant extent. We studied the detailed cellular adaptation reactions for a specified plasma intensity by time-resolved comparative proteome analyses of plasma treated vs. nontreated cells to elucidate the mechanisms of the observed improved wound healing and to define potential biomarkers and networks for the evaluation of plasma effects on human epithelial cells. K-means cluster analysis and time-related analysis of fold-change factors indicated concordantly clear differences between the short-term (up to 1 h) and long-term (24-72 h) adaptation reactions. Thus, the induction of Nrf2-mediated oxidative and endoplasmic reticulum stress response, PPAR-alpha/RXR activation as well as production of peroxisomes, and prevention of apoptosis already during the first hour after CAP treatment are important cell strategies to overcome oxidative stress and to protect and maintain cell integrity and especially microtubule dynamics. After resolving of stress, when stress adaptation was accomplished, the cells seem to start again with proliferation and cellular assembly and organization. The observed strategies and identification of marker proteins might explain the accelerated wound healing induced by CAP, and these indicators might be subsequently used for risk assessment and quality management of application of nonthermal plasma sources in clinical settings.

Risk of recurrence of Barrett's esophagus after successful endoscopic therapy

BACKGROUND AND AIMS

Previous estimates of incidence of intestinal metaplasia (IM) recurrence after achieving complete remission of IM (CRIM) through endoscopic therapy of Barrett's esophagus (BE) have varied widely. We performed a systematic review and meta-analysis of studies to estimate an accurate recurrence risk after CRIM.

METHODS

We performed a systematic search of multiple literature databases through June 2015 to identify studies reporting long-term follow-up after achieving CRIM through endoscopic therapy. Pooled incidence rate (IR) of recurrent IM, dysplastic BE, and high-grade dysplasia (HGD)/esophageal adenocarcinoma (EAC) per person-year of follow-up after CRIM was estimated. Factors associated with recurrence were also assessed.

RESULTS

We identified 41 studies that reported 795 cases of recurrence in 4443 patients over 10,427 patient-years of follow-up. This included 21 radiofrequency ablation studies that reported 603 cases of IM recurrence in 3186 patients over 5741 patient-years of follow-up. Pooled IRs of recurrent IM, dysplastic BE, and HGD/EAC after radiofrequency ablation were 9.5% (95% CI, 6.7-12.3), 2.0% (95% CI, 1.3-2.7), and 1.2% (95% CI, .8-1.6) per patient-year, respectively. When all endoscopic modalities were included, pooled IRs of recurrent IM, dysplastic BE, and HGD/EAC were 7.1% (95% CI, 5.6-8.6), 1.3% (95% CI, .8-1.7), and .8% (95% CI, .5-1.1) per patient-year, respectively. Substantial heterogeneity was noted. Increasing age and BE length were predictive of recurrence; 97% of recurrences were treated endoscopically.

CONCLUSIONS

The incidence of recurrence after achieving CRIM through endoscopic therapy was substantial. A small minority of recurrences were dysplastic BE and HGD/EAC. Hence, continued surveillance after CRIM is imperative. Additional studies with long-term follow-up are needed.

Proteomic Changes of Tissue-Tolerable Plasma Treated Airway Epithelial Cells and Their Relation to Wound Healing

Background. The worldwide increasing number of patients suffering from nonhealing wounds requires the development of new safe strategies for wound repair. Recent studies suggest the possibility of nonthermal (cold) plasma application for the acceleration of wound closure. Methods. An in vitro wound healing model with upper airway S9 epithelial cells was established to determine the macroscopically optimal dosage of tissue-tolerable plasma (TTP) for wound regeneration, while a 2D-difference gel electrophoresis (2D-DIGE) approach was used to quantify the proteomic changes in a hypothesis-free manner and to evaluate the balance of beneficial and adverse effects due to TTP application. Results. Plasma doses from 30 s up to 360 s were tested in relation to wound closure after 24 h, 48 h, 72 h, 96 h, and 120 h, in which lower doses (30, 60, and 120 s) resulted in dose-dependent improved wound healing rate compared to untreated cells. Thereby, the 120 s dose caused significantly the best wound healing properties after 96 and 120 h. The proteome analysis combined with IPA revealed that a lot of affected stress adaptation responses are linked to oxidative stress response emphasizing oxidative stress as a possible key event in the regeneration process of epithelial cells as well as in the adaptation to plasma exposure. Further cellular and molecular functions like proliferation and apoptosis were significantly up- or downregulated by all TTP treatments but mostly by the 120 s dose. Conclusions. For the first time, we were able to show plasma effects on cellular adaptation of upper airway epithelial S9 cells improving wound healing. This is of particular interest for plasma application, for example, in the surgery field of otorhinolaryngology or internal medicine.

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

BACKGROUND AND STUDY AIM

After thermal ablation of Barrett's esophagus (BE), stricture formation is reported in 5 to over 10% of patients. The question arises whether submucosal fluid injection prior to ablation may lower the risk of stricture formation. The aim of the present study was to evaluate the efficacy and safety of the new technique of Hybrid-APC which combines submucosal injection with APC.

PATIENTS AND METHODS

Patients who had a residual BE segment of at least 1 cm after endoscopic resection of early Barrett's neoplasia underwent thermal ablation of BE by Hybrid-APC. Prior to thermal ablation, submucosal injection of sodium chloride 0.9% was carried out using a flexible water-jet probe (Erbejet 2; Erbe Elektromedizin, Tuebingen, Germany). Check-up upper GI endoscopy was carried out 3 months after macroscopically complete ablation including biopsies from the neo-Z-line and the former BE segment, and recording of stricture formation.

RESULTS

From May 2011 to November 2012, a total of 60 patients (pt) were included in the study [55 pt male (92%); mean age 62 ± 9 years, range 42-79]. Ten patients were excluded from the study. In the remaining 50 pt, Hybrid-APC ablation and check-up endoscopy at 3 months were carried out. Forty-eight out of 50 pt (96%; ITT: 49/60, 82%) achieved macroscopically complete remission after a median of 3.5 APC sessions [SD 2.4; range 1-10]. Freedom from BE was histopathologically observed in 39/50 patients (78%). There was one treatment-related stricture (2%). Minor adverse events of Hybrid-APC were observed in 11 patients (22%).

CONCLUSIONS

According to this pilot series, Hybrid-APC was effective and safe for BE ablation in a tertiary referral center. The rate of stricture formation was only 2%. Further studies are required to confirm the present results.

GERMAN CLINICAL TRIALS REGISTER

DRKS00003369.

Electric discharge during electrosurgery

Electric discharge utilized for electrosurgery is studied by means of a recently developed method for the diagnostics of small-size atmospheric plasma objects based on Rayleigh scattering of microwaves on the plasma volume. Evolution of the plasma parameters in the near-electrode sheaths and in the positive column is measured and analyzed. It is found that the electrosurgical system produces a glow discharge of alternating current with strongly contracted positive column with current densities reaching 10(3) A/cm(2). The plasma electron density and electrical conductivities in the channel were found be 10(16) cm(-3) and (1-2) Ohm(-1) cm(-1), respectively. The discharge interrupts every instance when the discharge-driving AC voltage crosses zero and re-ignites again every next half-wave at the moment when the instant voltage exceeds the breakdown threshold.

Meta-analysis of endoscopic therapy for low-grade dysplasia in Barrett's oesophagus

Background

The optimal management of patients with Barrett's-associated low-grade dysplasia (LGD) is unclear. The objective of this study was to identify systematically all reports of endoscopic treatment of LGD, and to assess outcomes in terms of disease progression, eradication of dysplasia and intestinal metaplasia, and complication rates.

Methods

A systematic review of articles reporting endoscopic treatment of LGD was conducted in accordance with PRISMA guidelines. MEDLINE and Embase databases were searched to identify the relevant literature. Rates of complete eradication of intestinal metaplasia (CE-IM) and dysplasia (CE-D) were reported. The pooled incidence of progression to cancer was calculated following endoscopic therapy.

Results

Thirty-seven studies met the inclusion criteria, reporting outcomes of endoscopic therapy for 521 patients with LGD. The pooled incidence of progression to cancer was 3·90 (95 per cent confidence interval (c.i.) 1·27 to 9·10) per 1000 patient-years. CE-IM and CE-D were achieved in 67·8 (95 per cent c.i. 50·2 to 81·5) and 88·9 (83·9 to 92·5) per cent of patients respectively. The commonest adverse event was stricture formation.

Conclusion

Reports of endoscopic therapy were heterogeneous and follow-up periods were short. There is a high likelihood of historical overdiagnosis of LGD. Endoscopic therapy, particularly radiofrequency ablation, appears safe and effective at eradicating LGD, but does not eliminate the risk of progression to cancer.

Advances in endoluminal therapy for esophageal cancer

Advances in endoscopic therapy have resulted in dramatic changes in the way early esophageal cancer is managed as well as in the palliation of dysphagia related to advanced esophageal cancer. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are effective therapies for accurate histopathologic staging and provide a potential for complete cure. Mucosal ablative techniques (radiofrequency ablation and cryotherapy) are effective adjuncts to EMR and ESD and reduce the occurrence of synchronous and metachronous lesions within the Barrett esophagus. The successes of these techniques have made endoscopic therapy the primary means of management of early esophageal cancer.

Minimally invasive treatments for Barrett's esophagus

The incidence of esophageal adenocarcinoma has been rising in recent years. Barrett's esophagus (BE) is widely considered the precursor of invasive adenocarcinoma. High-grade dysplasia (HGD) in BE is the critical step before invasive esophageal adenocarcinoma. Currently, numerous minimally invasive treatments for BE with HGD are available; however, there have been no clear-cut guidelines for a large number of patients due to the individualization of therapy and the absence of long-term outcome evaluation. This review briefly summarizes currently available minimally invasive therapeutic modalities for BE and compares their therapeutic outcomes, with an aim to aid in the choice of the appropriate treatment.

Molecular biomarkers and ablative therapies for Barrett's esophagus

Barrett's esophagus is the major risk factor for esophageal adenocarcinoma. Endoscopic interventions that ablate Barrett's esophagus mucosa lead to replacement with a new squamous (neosquamous) mucosa, but it can be difficult to achieve complete ablation. Knowing whether cancer is less likely to develop in neosquamous mucosa or residual Barrett's esophagus after ablation is critical for determining the efficacy of treatment. This issue can be informed by assessing biomarkers that are associated with an increased risk of progression to adenocarcinoma. Although there are few postablation biomarker studies, evidence suggests that neosquamous mucosa may have a reduced risk of adenocarcinoma in patients who have been treated for dysplasia or cancer, but some patients who do not have complete eradication of nondysplastic Barrett's esophagus may still be at risk. Biomarkers could be used to optimize endoscopic surveillance strategies following ablation, but this needs to be assessed by clinical studies and economic modeling.

Radiofrequency ablation offers a Reliable Surgical Modality for the Treatment of Barrett's Esophagus with a Minimal Learning Curve

Radiofrequency ablation (RFA) has gained popularity as treatment for Barrett's esophagus. Inclusive series of patients from initiation of our Barrett's Therapy Program were studied. Review of patients undergoing RFA for Barrett's was performed from September 2008 to May 2011. Patients’ outcomes were recorded and analyzed using standard statistical methods. Seventy patients were treated. Average age was 61 (28–70); 80 per cent were male. Seventy-four per cent had dysplasia; 44 low-grade and eight high-grade. A total of 75.7 per cent of patients had long and 24.3 per cent had short segment Barrett's. Procedures per patient ranged from one to seven. Number of treatments in long- and short-segment groups were not different ( P = 0.11). The maximum number of treatments in the short-segment group was five with a median of three (44.3%). For long segment, the maximum of RFA procedures was seven, with a median of three (30.8%). Average procedure time was 20.8 minutes for long and 17.9 minutes for short segment. Mean follow-up was 16.1 (2–38) months. Complete response was accomplished in 81 per cent. There were 93.3 per cent of complete responders in the short-segment group versus 75 per cent in the long ( P = 0.24). Complications included dysphagia (1), transient chest and cervical pain (1), and abdominal pain (1). Comparing the first 25 per cent of the RFA procedures to the later 75 per cent or first 50 per cent to second 50 per cent, there was no difference in operative time or complications. Two patients recurred, both in the long-segment group. RFA is a safe and effective means to eradicate Barrett's. By measure of treatment time, complication rate, and efficacy of therapy, there is minimal or no “learning curve” for experienced endoscopists.

Barrett's esophagus with high-grade dysplasia: focus on current treatment options

High-grade dysplasia (HGD) in Barrett's esophagus (BE) is the critical step before invasive esophageal adenocarcinoma. Although its natural history remains unclear, an aggressive therapeutic approach is usually indicated. Esophagectomy represents the only treatment able to reliably eradicate the neoplastic epithelium. In healthy patients with reasonable life expectancy, vagal-sparing esophagectomy, with associated low mortality and low early and late postoperative morbidity, is considered the treatment of choice for BE with HGD. Patients unfit for surgery should be managed in a less aggressive manner, using endoscopic ablation or endoscopic mucosal resection of the entire BE segment, followed by lifelong surveillance. Patients eligible for surgery who present with a long BE segment, multifocal dysplastic lesions, severe reflux symptoms, a large fixed hiatal hernia or dysphagia comprise a challenging group with regard to the appropriate treatment, either surgical or endoscopic.

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.

Prevalence and predictors of recurrent neoplasia after ablation of Barrett's esophagus

BACKGROUND

The incidence and risk factors for recurrence of dysplasia after ablation of Barrett's esophagus (BE) have not been well defined.

OBJECTIVE

To determine the rate and predictors of dysplasia/neoplasia recurrence after photodynamic therapy (PDT) in BE.

SETTING

Retrospective analysis of a prospective cohort of BE patients seen at a specialized BE unit.

METHODS

Patients underwent a standard protocol assessment with esophagogastroduodenoscopy and 4-quadrant biopsies every centimeter at 3-month intervals after ablation. Recurrence was defined as the appearance of any grade of dysplasia or neoplasia after 2 consecutive endoscopies without dysplasia. Entry histology, demographics, length of BE, presence and length of diaphragmatic hernia, EMR, stricture formation, nonsteroidal anti-inflammatory drug use, smoking, and the presence of nondysplastic BE or squamous epithelium were assessed for univariate associations. Time-to-recurrence analysis was done by using Cox proportional hazards regression. A multivariate model was constructed to establish independent associations with recurrence.

RESULTS

A total of 363 patients underwent PDT with or without EMR. Of these, 261 patients were included in the final analysis (44 lost to follow-up, 46 had residual dysplasia, and 12 had no dysplasia at baseline). Indication for ablation was low-grade dysplasia (53 patients, 20%), high-grade dysplasia (152 patients, 58%), and intramucosal cancer (56 patients, 21%). Median follow-up was 36 months (interquartile range 18-79 months). Recurrence occurred in 45 patients. Median time to recurrence was 17 months (interquartile range 8-45 months). Significant predictors of recurrence on the multivariate model were older age (hazard ratio [HR] 1.04, P=.029), presence of residual nondysplastic BE (HR 2.88, P=.012), and a history of smoking (HR 2.68, P=.048).

LIMITATIONS

Possibility of missing prevalent dysplasia despite aggressive surveillance.

CONCLUSION

Recurrence of dysplasia/neoplasia after PDT ablation is associated with advanced age, smoking, and residual BE.

History, molecular mechanisms, and endoscopic treatment of Barrett's esophagus

This report is an adjunct to the American Gastroenterological Association Institute's medical position statement and technical review on the management of Barrett's esophagus, which will be published in the near future. Those documents will consider a number of broad questions on the diagnosis, clinical features, and management of patients with Barrett's esophagus, and the reader is referred to the technical review for an in-depth discussion of those topics. In this report, we review historical, molecular, and endoscopic therapeutic aspects of Barrett's esophagus that are of interest to clinicians and researchers.

Safety, tolerability, and efficacy of endoscopic low-pressure liquid nitrogen spray cryotherapy in the esophagus

Endoscopic cryotherapy is a new technique for ablation of esophageal dysplasia and neoplasia. Preliminary studies have shown it to be safe and effective for this indication. The objective of this study is to characterize safety, tolerability, and efficacy of low-pressure liquid nitrogen endoscopic spray cryotherapy ablation in a large cohort across multiple study sites. Parallel prospective treatment studies at four tertiary care academic medical centers in the U.S. assessed spray cryotherapy in patients with Barrett's esophagus with or without dysplasia, early stage esophageal cancer, and severe squamous dysplasia who underwent cryotherapy ablation of the esophagus. All patients were contacted between 1 and 10 days after treatment to assess for side effects and complications of treatment. The main outcome measurement was the incidence of serious adverse events and side effects from treatment. Complete response for high-grade dysplasia (HGD) (CR-HGD), all dysplasia (CR-D), intestinal metaplasia (CR-IM) and cancer (CR-C) were assessed in patients completing therapy during the study period. A total of 77 patients were treated for Barrett's high-grade dysplasia (58.4%), intramucosal carcinoma (16.9%), invasive carcinoma (13%), Barrett's esophagus without dysplasia (9.1%), and severe squamous dysplasia (2.6%). Twenty-two patients (28.6%) reported no side effects throughout treatment. In 323 procedures, the most common complaint was chest pain (17.6%) followed by dysphagia (13.3%), odynophagia (12.1%), and sore throat (9.6%). The mean duration of any symptoms was 3.6 days. No side effects were reported in 48% of the procedures (155/323). Symptoms did not correlate with age, gender, diagnosis, or to treatment early versus late in the patient's or site's experience. Logit analysis showed that symptoms were greater in those with a Barrett's segment of 6 cm or longer. Gastric perforation occurred in one patient with Marfan's syndrome. Esophageal stricture developed in three, all successfully treated with dilation. In 17 HGD patients, cryotherapy produced CR-HGD, CR-D, and CR-IM of 94%, 88%, and 53%, respectively. Complete regression of cancer and HGD was seen in all seven patients with intramucosal carcinoma or stage I esophageal cancer. Endoscopic spray cryotherapy ablation using low-pressure liquid nitrogen in the esophagus is safe, well-tolerated, and efficacious.

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.

Safety, tolerability, and efficacy of endoscopic low-pressure liquid nitrogen spray cryotherapy in the esophagus

Endoscopic cryotherapy is a new technique for ablation of esophageal dysplasia and neoplasia. Preliminary studies have shown it to be safe and effective for this indication. The objective of this study is to characterize safety, tolerability, and efficacy of low-pressure liquid nitrogen endoscopic spray cryotherapy ablation in a large cohort across multiple study sites. Parallel prospective treatment studies at four tertiary care academic medical centers in the U.S. assessed spray cryotherapy in patients with Barrett's esophagus with or without dysplasia, early stage esophageal cancer, and severe squamous dysplasia who underwent cryotherapy ablation of the esophagus. All patients were contacted between 1 and 10 days after treatment to assess for side effects and complications of treatment. The main outcome measurement was the incidence of serious adverse events and side effects from treatment. Complete response for high-grade dysplasia (HGD) (CR-HGD), all dysplasia (CR-D), intestinal metaplasia (CR-IM) and cancer (CR-C) were assessed in patients completing therapy during the study period. A total of 77 patients were treated for Barrett's high-grade dysplasia (58.4%), intramucosal carcinoma (16.9%), invasive carcinoma (13%), Barrett's esophagus without dysplasia (9.1%), and severe squamous dysplasia (2.6%). Twenty-two patients (28.6%) reported no side effects throughout treatment. In 323 procedures, the most common complaint was chest pain (17.6%) followed by dysphagia (13.3%), odynophagia (12.1%), and sore throat (9.6%). The mean duration of any symptoms was 3.6 days. No side effects were reported in 48% of the procedures (155/323). Symptoms did not correlate with age, gender, diagnosis, or to treatment early versus late in the patient's or site's experience. Logit analysis showed that symptoms were greater in those with a Barrett's segment of 6 cm or longer. Gastric perforation occurred in one patient with Marfan's syndrome. Esophageal stricture developed in three, all successfully treated with dilation. In 17 HGD patients, cryotherapy produced CR-HGD, CR-D, and CR-IM of 94%, 88%, and 53%, respectively. Complete regression of cancer and HGD was seen in all seven patients with intramucosal carcinoma or stage I esophageal cancer. Endoscopic spray cryotherapy ablation using low-pressure liquid nitrogen in the esophagus is safe, well-tolerated, and efficacious.

A cost-utility analysis of ablative therapy for Barrett's esophagus

BACKGROUND & AIMS

Recommendations for patients with Barrett's esophagus (BE) include endoscopic surveillance with esophagectomy for early-stage cancer, although new technologies to ablate dysplasia and metaplasia are available. This study compares the cost utility of ablation with that of endoscopic surveillance strategies.

METHODS

A decision analysis model was created to examine a population of patients with BE (mean age 50), with separate analyses for patients with no dysplasia, low-grade dysplasia (LGD), or high-grade dysplasia (HGD). Strategies compared were no endoscopic surveillance; endoscopic surveillance with ablation for incident dysplasia; immediate ablation followed by endoscopic surveillance in all patients or limited to patients in whom metaplasia persisted; and esophagectomy. Ablation modalities modeled included radiofrequency, argon plasma coagulation, multipolar electrocoagulation, and photodynamic therapy.

RESULTS

Endoscopic ablation for patients with HGD could increase life expectancy by 3 quality-adjusted years at an incremental cost of <$6,000 compared with no intervention. Patients with LGD or no dysplasia can also be optimally managed with ablation, but continued surveillance after eradication of metaplasia is expensive. If ablation permanently eradicates >or=28% of LGD or 40% of nondysplastic metaplasia, ablation would be preferred to surveillance.

CONCLUSIONS

Endoscopic ablation could be the preferred strategy for managing patients with BE with HGD. Ablation might also be preferred in subjects with LGD or no dysplasia, but the cost effectiveness depends on the long-term effectiveness of ablation and whether surveillance endoscopy can be discontinued after successful ablation. As further postablation data become available, the optimal management strategy will be clarified.

Treatment of Barrett's esophagus with high-grade dysplasia

The incidence of esophageal adenocarcinoma is increasing in the USA, now accounting for at least 4% of US cancer-related deaths. Barrett's esophagus is the main risk factor for the development of esophageal adenocarcinoma. The annual incidence of development of adenocarcinoma in Barrett's esophagus is approximately 0.5% per year, representing at least a 30-40-fold increase in risk from the general population. High-grade dysplasia is known to be the most important risk factor for progression to adenocarcinoma. Traditionally, esophagectomy has been the standard treatment for Barrett's esophagus with high-grade dysplasia. This practice is supported by studies revealing unexpected adenocarcinoma in 29-50% of esophageal resection specimens for high-grade dysplasia. In addition, esophagectomy employed prior to tumor invasion of the muscularis mucosa results in 5-year survival rates in excess of 80%. Although esophagectomy can result in improved survival rates for early-stage cancer, it is accompanied by significant morbidity and mortality. Recently, more accurate methods of surveillance and advances in endoscopic therapies have allowed scientists and clinicians to develop treatment strategies with lower morbidity for high-grade dysplasia. Early data suggests that carefully selected patients with high-grade dysplasia can be managed safely with endoscopic therapy, with outcomes comparable to surgery, but with less morbidity. This is an especially attractive approach for patients that either cannot tolerate or decline surgical esophagectomy. For patients that are surgical candidates, high-volume centers have demonstrated improved morbidity and mortality rates for esophagectomy. The addition of laparoscopic esophagectomy adds a less invasive surgical resection to the treatment armanentarium. Esophagectomy will remain the gold-standard treatment of Barrett's esophagus with high-grade dysplasia until clinical research validates the role of endoscopic therapies. Current treatment strategies for Barrett's esophagus with high-grade dysplasia will be reviewed.

Treatment of gastrointestinal diseases with second-generation argon plasma coagulation: an analysis of 260 cases

AIM: To investigate the safety and efficacy of the second-generation argon plasma coagulation (VIO APC) for gastrointestinal diseases.

METHODS: During 2007-09-14/2008-10-22, 260 patients were treated using VIO APC in a total of 289 sessions. For various indications, the new VIO APC device was used. Safety and efficacy of VIO APC were recorded after each individual treatment session.

RESULTS: The mean number of treatment sessions required using VIO APC in various indications was 1.11 ± 0.31. In the palliative treatment of gastric adenocarcinoma, it was 2.50; in endoscopic hemostasis, it was 1.23; in the treatment of colorectal polypi, it was 1.15, in the treatment of upper gastrointestinal polypi, it was 1.03, in the management of self-expand stent overgrowth or tumor stenosis, it was 1.17; in the ablation of Barrett's esophagus, it was 1.13; in the ablation of gastric dysplasia, gastritis verrucosa, gastric xanthelasma and gastric or duodenal liparomphalus, only 1 session was needed. Minor complications (pain, dysphagia/odynophagia, asymptomatic gas accumulation in the intestinal wall) were observed in 10.1%-20% sessions, but no major complications (hemorrhage, perforation, stenosis) were observed.

CONCLUSION: VIO APC is effective and safe for various gastrointestinal conditions. It can be widely applied to daily endoscopic treatment.

Endoscopic approaches to Barrett's oesophagus with high-grade dysplasia/early mucosal cancer

This chapter will review the endoscopic approaches to the management of Barrett's oesophagus with high-grade dysplasia/early mucosal cancer. Factors to consider when evaluating patients for endoscopic management are detailed. Ablation and resection methods for eradication of Barrett's oesophagus with high-grade dysplasia/early mucosal cancer are reviewed. Strategies for combining therapies to achieve safe and effective eradication are discussed. Recommendations for complete eradication of all Barrett's mucosa and follow-up considerations are put forward.

Barrett's esophagus: pathogenesis, treatment, and prevention

Esophageal adenocarcinoma is the most common type of esophageal cancer seen in the United States and Western Europe. Barrett's esophagus (BE) is a well-known risk factor for esophageal adenocarcinoma and is believed to be found in 6% to 12% of patients undergoing endoscopy for gastroesophageal reflux disease and in more than 1% of all patients undergoing endoscopy. This article focuses on the pathogenesis, treatment, and prevention of BE.

Pain sensation and neuromuscular stimulation during argon plasma coagulation in gastrointestinal endoscopy

BACKGROUND

Argon plasma coagulation (APC) is a thermal coagulation technique that uses ionized argon for contact-free transmission of high-frequency electrical current to tissue. Prospective data on complications with the new APC-2 (VIO) system are lacking.

METHODS

A prospective trial was conducted with 152 patients treated for various gastrointestinal diseases using three modes of the APC-2. The study aimed to assess complications, focusing on the pain and neuromuscular stimulation (NMS) experienced during and after treatment. Patients reported pain and NMS using a scale ranging from 0 to 10 and were interviewed for symptoms such as tingling, paresthesia, muscle pain, and cramping or twitching. The endoscopists also graded NMS using a separate questionnaire.

RESULTS

A total of 85 males and 67 females (median age, 66 years) were enrolled in the study. All APC therapies were completed successfully. Two peri-interventional perforations were recorded. Of the 152 patients, 26 (17%) reported pain sensation during or after APC. The median pain sensation reported by the patients on the standardized scale was 3.7. The findings showed NMS in 14 (9.2%) of the 152 patients. Significantly more NMS events were seen with pulsed APC than with forced or precise APC. Additional risk factors for NMS were gender (female) and type of sedation (combination midazolam and pethidine). No complications were noted among patients with intracardiac defibrillators or cardiac pacemakers.

CONCLUSIONS

According to the findings, APC may be associated with minor complications such as pain sensation and NMS. These complications were rarely seen, but occurred more often with pulsed APC than with forced or precise APC. Physicians should be aware of these complications.

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.

Barrett's oesophagus: long-term follow-up after complete ablation with argon plasma coagulation and the factors that determine its recurrence

BACKGROUND

Argon plasma coagulation seems to be a promising technique for ablation of Barrett's oesophagus, yet few long-term efficacy data are available.

AIM

To report on a long-term follow-up and the factors that determine the recurrence of intestinal metaplasia in a cohort of patients with non dysplastic, intestinal type Barrett's oesophagus, after complete ablation of the metaplastic mucosa with argon plasma coagulation.

METHODS

Ninety-six patients underwent endoscopic argon plasma coagulation with adequate acid suppression obtained through a continuous omeprazole therapy (50 patients) or through laparoscopic fundoplication (46 patients). Complete ablation was achieved in 94 patients who underwent follow-up. Endoscopic and histological examinations were performed every 12 months.

RESULTS

The median follow-up of the patients was 36 months (range 18-98). A recurrence of intestinal metaplasia was found in 17 patients (18%), with an annual recurrence rate of 6.1%. Neither dysplasia, nor adenocarcinoma were found during the follow-up. Through the use of logistic regression analysis, previous laparoscopic fundoplication was associated with a reduced recurrence rate of intestinal metaplasia (odds ratio 0.30, 95% confidence interval 0.10-0.93).

CONCLUSIONS

The long-term recurrence of intestinal type Barrett's oesophagus was low after complete ablation with argon plasma coagulation. The control of oesophageal acidity acid exposure with laparoscopic fundoplication seems to reduce the recurrence rate.

In vivo evaluation of argon plasma coagulation in a porcine model

BACKGROUND

Argon plasma coagulation (APC) is a noncontact form of monopolar electrocautery. One purported advantage of APC includes a limit to the depth of injury. It is unclear from previous studies whether the depth of injury is limited to superficial tissue layers with the settings used in clinical practice.

OBJECTIVE

To evaluate the depth and the area of APC-induced injury by using new modes of APC delivery in an in vivo porcine model in the setting of colonoscopy.

DESIGN

Blinded quasi-experiment.

SUBJECTS

Six swine.

INTERVENTION

Colonoscopy with the swine under general anesthesia, with application of APC in 2 different pulsed modes and varying power settings and duration of application.

MAIN OUTCOME MEASUREMENTS

Surface area and depth of colonic mucosal injury. Qualitative histologic analysis of each site of APC application was performed on formalin-fixed specimens after euthanizing the swine.

RESULTS

Muscularis propria injury occurred in 22% of lesions with 10 W, 62% of lesions with 20 W, 86% of lesions with 40 W, and 80% of lesions with 60 W. Muscularis propria injury occurred in 42% of lesions at 1 second, 66% of lesions at 3 seconds, and 69% of lesions at 5 seconds. Depth of injury was significantly correlated with total energy delivered (P = .001, r = 0.75). Surface area was significantly associated with total energy delivered (P < .001, r = 0.81).

LIMITATIONS

This study was performed in distal swine colon rather than human colon. Colon tissue response to APC injury may differ from swine to human colon. The application distance from the APC probe to the colonic tissue may have varied between applications.

CONCLUSIONS

Muscularis propria injury occurs across a broad range of clinically used APC settings. The frequency of deep injury and the surface area of the lesion increases with total energy delivered. The lowest power settings (10-20 W) and the shortest durations have the lowest risk of deep tissue injury.

Ablation of nonneoplastic Barrett's mucosa using argon plasma coagulation with concomitant esomeprazole therapy (APBANEX): a prospective multicenter evaluation

BACKGROUND

Complete reversal of Barrett's epithelium (BE) achieved by treatment with argon plasma coagulation (APC) is variable. The aim of this prospective study was to evaluate the effectiveness of high-power APC in a multicenter trial.

METHODS

In seven study centers, 60 patients (mean age 57, range 27-77) with nonneoplastic BE (length 1-8 cm) were recruited for treatment with high-power APC (90 W) in combination with esomeprazole 80 mg/day. Video endoscopy, chromoendoscopy, and four-quadrant biopsies (4QB) were carried out during baseline endoscopy and regular intervals. The effect of ablation was classified as complete remission (CR), partial remission, or minor response.

RESULTS

Fifty-one of the 60 patients completed ablation therapy. Three patients were lost to follow-up (FU). After a mean of 2.6 APC sessions (range 1-5) and a mean FU of 14 months (range 12-32), CR was achieved in 37 of 48 patients (77%). Major complications occurred in five of 51 patients (9.8%).

CONCLUSIONS

Complete ablation of BE can be achieved in a high percentage of patients even in a multicenter design using high-power APC. However, APC has a relevant morbidity. Therefore, ablation of nonneoplastic BE cannot be recommended generally because incidence of cancer in BE is low.

Effects of low-power argon plasma coagulation thermoablation of Barrett's epithelium on oesophageal motility

INTRODUCTION

Oesophageal dysmotility contributes to the pathogenesis of Barrett's epithelium (BE) allowing prolonged mucosal contact with injurious refluxate. Argon plasma coagulation (APC) is effective for BE ablation, but it is unknown whether the procedure affects oesophageal motility.

AIM

To assess the effect of low power (30 W) APC therapy on oesophageal motility in patients with BE.

METHODS

Thirty-three patients with at least 4 cm of BE underwent oesophageal manometry before and after APC ablation. All were on proton pump inhibitors. Oesophageal body peristaltic wave duration and amplitude, and lower oesophageal sphincter (LOS) pressure and length were compared before and after treatment.

RESULTS

In a total of 28 men and five women, with a mean age of 63.4 years (range 39-79) and mean BE length 6.5 cm (range 4-19), macroscopic clearance was achieved in 28 patients. A small statistically significant (P<0.05) increase in peristaltic wave amplitude was seen after APC [mean (SD) mmHg before versus after: 30.4 (15.2) versus 36.2 (20.1) at 13.5 cm, 47.6 (27.1) versus 54.5 (26.8) at 8.5 cm, and 51.2 (35.3) versus 58 (34.4) at 3.5 cm above the LOS]. No changes in either peristaltic wave duration or LOS parameters [mean (SD) pressure 10.6 (5.6) versus 10.3 (4.3) mmHg; length 2.8 (1.3) versus 2.8 (1.0) cm] were observed.

CONCLUSION

APC ablation of BE at a power setting of 30 W does not impair oesophageal motility.

The endoscopic diagnosis and staging of oesophageal adenocarcinoma

The endoscopic evaluation of patients with oesophageal adenocarcinoma does not only serve the purpose of diagnosing the lesion and obtaining biopsies for histological evaluation: a systematic description of advanced lesions is also required to guide further therapeutic decisions. New endoscopic imaging modalities hold the promise of better endoscopic detection of early cancer and its precursor lesions in Barrett's oesophagus. Video-autofluorescence and narrow band imaging are the most promising techniques in this respect. The former may be used as a 'red flag' technique, identifying lesions that remain occult with white light endoscopy; the latter may be used as a targeted imaging technique, allowing for detailed inspection of the mucosal and vascular patterns that may help to distinguish early neoplasia from non-dysplastic tissue. Currently, prototypes are under investigation that combine high-resolution endoscopy, narrow band imaging and video-autofluorescence in one endoscopy system. Endoscopic ultrasonography (EUS) is superior to any other imaging modality in the assessment of local tumour infiltration of oesophageal adenocarcinoma and locoregional lymph nodes status. EUS allows for the identification of patients with advanced disease who are unlikely to benefit from attempts at curative surgery and in whom a conservative palliative treatment is indicated. EUS may also play a role in the selection of patients for local endoscopic treatment of early oesophageal cancer. EUS guided fine needle aspiration (EUS-FNA) of locoregional lymph nodes is safe with a high sensitivity and an impeccable specificity for assessment of malignant involvement. The indications for EUS-FNA of lymph nodes, however, depend on local treatment protocols: caeliac nodes (M1a) and lymph nodes located at or above the subcarinal area are the most widely used indications. In addition, it may be important if the choice for specific treatment protocols (e.g. neoadjuvant chemoradiotherapy) depends on lymph node status.

Genomic analysis of Barrett's esophagus after ablative therapy: persistence of genetic alterations at tumor suppressor loci

Barrett's esophagus (BE) is a major predisposing factor for the development of esophageal adenocarcinoma. Current strategies for treatment of BE, both dysplastic and nondysplastic, include photodynamic therapy (PDT) and argon plasma coagulation (APC). However, the effect of ablative therapy at the genetic level is unclear. We performed loss of heterozygosity (LOH) analysis of BE in baseline and follow-up biopsy specimens from 21 patients with BE (17 male, 4 female) treated with PDT and/or APC. At baseline, 14 patients had intestinal metaplasia without dysplasia (MET), 4 low-grade dysplasia (LGD) and 3 high-grade dysplasia (HGD). LOH was assessed using a panel of 9 polymorphic markers for evaluation of the P53 gene on 17p, P16 on 9p, DCC and SMAD4 on 18q and the APC gene on 5q. The tissue specimens obtained at baseline (t = 0) were analysed, as well as the first (t = 1; mean interval: 4 months) and last (t = 2; mean interval: 8 months) available biopsy with residual or recurrent BE after ablation. At t = 0, allelic loss was detected of 5q in 27%, 9p in 56%, 17p in 31% and 18q in 6% of informative cases. At t = 1 (18 patients with persistent MET and 3 with LGD) and at t = 2 (8 MET, 2 LGD), the LOH patterns were not statistically different from t = 0. Further, multiple genetic lineages before and after therapy were detected in 15 cases illustrating the multiclonal nature of BE. We conclude that recurrent and/or persistent BE after ablative therapy still contains genetic alterations associated with malignant progression to cancer. Therefore, the goal of treatment should be the complete elimination of Barrett's mucosa.

Beyond heartburn: a systematic review of the extra-oesophageal spectrum of reflux-induced disease

BACKGROUND

Gastro-oesophageal reflux disease (GORD) is a chronic condition affecting up to one-quarter of the Western population. GORD is characterized by heartburn and acid regurgitation, but is reported to be associated with a spectrum of extra-oesophageal symptoms.

OBJECTIVE

The aim of this systematic review was to critically evaluate postulated extra-oesophageal symptoms of GORD.

METHODS

Extra-oesophageal symptoms were identified from population-based studies evaluating their association with GORD (either defined as heartburn and/or acid regurgitation, or diagnosed in general practice). The response of these symptoms to acid-suppressive therapy was investigated using randomized, double-blind, placebo-controlled studies. Pathogenic mechanisms were evaluated using clinical and preclinical studies.

RESULTS

An association between GORD and symptoms or a diagnosis of chest pain/angina, cough, sinusitis and gall-bladder disease was evident from three eligible population-based studies of GORD. Randomized placebo-controlled studies (n=20) showed that acid-suppressive therapy provides symptomatic relief of chest pain, asthma and, potentially, chronic cough and laryngitis. Mechanistic models, based on direct physical damage by refluxate or vagally mediated reflexes, support a causal role for GORD in chest pain and respiratory symptoms, but not in gall-bladder disease.

CONCLUSION

GORD is likely to play a causal role in chest pain and possibly asthma, chronic cough and laryngitis. Further investigation is desirable, particularly for other potential extra-oesophageal manifestations of GORD such as chronic obstructive pulmonary disease, sinusitis, bronchitis and otitis. Acid-suppressive therapy is likely to benefit patients with non-cardiac chest pain, but further placebo-controlled studies are needed for other symptoms comprising the extra-oesophageal spectrum of GORD.

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.