A Medical Device Daily

Clinical trial results presented at this week's Digestive Disease Week (DDW) meeting in Chicago reveal that endoscopic radio frequency ablation performed in a community practice setting is safe and effective for eradicating a pre-cancerous esophageal condition known as Barrett's esophagus.

The study, titled "Radiofrequency Ablation of Barrett Esophagus: Outcomes of 429 Patients from a Multi-center Community Practice Registry," was presented by Ronald Pruitt, MD, of Nashville Clinical Research (Nashville, Tennessee), at a scientific session sponsored by the American Society for Gastrointestinal Endoscopy (Oak Brook, Illinois).

Pruitt reported on 429 patients with Barrett's esophagus, with and without advanced dysplasia (cellular signs of advanced progression towards cancer), who were treated with radiofrequency ablation using the HALO ablation system from Barrx Medical (Sunnyvale, California) over the last four years.

He added that the adverse event rate was favorable, with a low stricture risk (about 1%) and no serious adverse events. After an average of two ablation procedures and 20-month follow-up, 77% of patients were cured of their Barrett's disease. For those patients that had baseline evidence of dysplasia, 100% had complete eradication of all signs of dysplasia.

"We believe that the results of our trial are unique and relevant to the scientific knowledge-base, as this is the largest patient experience reported to date and the first multi-center trial conducted at community practice centers for using radio frequency ablation to eradicate Barrett's esophagus," said Pruitt. "Most importantly, we found that the safety and efficacy outcomes garnered in this clinical setting comport with those from reported trials conducted as predominantly academic tertiary referral centers."

Study centers were comprised of large community practices with expertise in therapeutic endoscopy and the management of Barrett's esophagus. Radio frequency ablation was applied with a balloon-based circumferential device and an endoscope mounted focal device.

Patients underwent biopsy sampling of tissue from the esophagus at regular intervals to determine if all Barrett's disease had been eradicated. To be considered a "complete responder," all biopsy samples had to be normal.

"This study is highly relevant and represents an important contribution to the science related to Barrett's esophagus therapy," said David Utley, MD, chief medical officer at Barrx Medical. "The study's strengths lie in its large number of studied patients, relatively long follow-up and objective histology endpoints."

Barrx Medical develops treatment solutions for Barrett's esophagus, a precancerous condition of the lining of the esophagus caused by gastroesophageal reflux disease, or GERD. Its main product, the HALO360 System, provides a uniform and controlled ablation effect, which removes the diseased tissue and allows regrowth of normal cells.

The HALO90 System is mounted on the end of an endoscope and used to treat smaller, non-circumferential areas of disease.

In other news from Digestive Disease Week:

• Ethicon Endo-Surgery (Cincinnati) said that multiple studies presented this week demonstrate that the company's investigational Toolbox enables natural orifice translumenal endoscopic surgery (NOTES) procedures without laparoscopic support in porcine models.

One of the studies concluded that a new adaptable, minimally invasive surgical platform for NOTES and single-site laparoscopy (SSL) was successfully used to complete a variety of key surgical activities critical to pure natural orifice surgery and SSL.

The seven studies presented at DDW, which involved porcine models and a variety of NOTES procedures, follows 15 studies involving Ethicon Endo-Surgery devices presented at the Society of American Gastrointestinal and Endoscopic Surgeons annual meeting in April.

Ethicon said that in the coming months, the Toolbox for natural orifice surgery will be evaluated in a human clinical trial under an investigational device exemption from the FDA.

"To date, most NOTES procedures performed in humans have been with laparoscopic support. In our study, we found several of the devices in the Ethicon Endo-Surgery Toolbox could successfully be used to address some of the critical visibility and access obstacles present with a pure NOTES approach, warranting further investigation," said Klaus Thaler, MD, of the department of surgery, University of Missouri Health System.

Investigators of the study titled, "The Development and Testing of an Adaptable Minimally-Invasive Surgical Platform – The Hydra," found that this surgical platform addressed several challenges with NOTES, including visibility, platform stability and adaptability to be used in multiple interventions and procedures.

The surgical platform was used both transgastrically and transvaginally completing multiple key surgical activities that included dissection, ligation, and specimen retrieval. The study, presented as a poster at DDW, involved porcine models and was conducted by investigators from Sahlgrenska University Hospital (Gothenburg, Sweden) and Imperial College (London).

"With the introduction of this adaptable minimally-invasive surgical platform, we believe we will be able to further address many of the issues experienced when NOTES or SSL procedures are performed with conventional surgical equipment designed for standard endoscopic or laparoscopic use," said Kenneth Sumner, PhD, vice president, clinical and regulatory affairs at Ethicon Endo-Surgery.

"We plan to continue our research to investigate the existing contents of the Ethicon Endo-Surgery Toolbox for natural orifice surgery, as well as develop additional products for inclusion in it that may help fulfill the promise of this approach to minimally invasive surgery," he said.

Another poster presentation titled "Hybrid Transgastric NOTES Cholecystectomy in a Porcine Model Using a Magnetically Anchored Cautery and Novel Instrumentation," conducted by the University of Texas Southwestern Medical Center demonstrated preliminary feasibility for a particularly difficult NOTES procedure, transgastric cholecystectomy.

Several devices specifically designed for natural orifice surgery were utilized in the study, including a live video manipulation (LVM) system and magnetically anchoring and guidance system (MAGS). Study investigators specifically cited the retraction abilities of the grasper and improved visibility of the provided by LVM, the latter which greatly reduced the workload on the surgical team.

The content of the Ethicon Endo-Surgery Toolbox includes Tissue Apposition System, Steerable Flex Trocar with Rotary Access Needle, Flexible Bipolar Hemostasis Forceps, Flexible Maryland Dissector, Articulating Hook Knife, Articulating Snare, Articulating Needle Knife, Articulating Graspers and Articulating Biopsy Forceps.

Those devices listed will be used within the IDE trial. The Adaptable Minimally-Invasive Surgical Platform and MAGS are limited to non-clinical applications at this time.

Ethicon Endo-Surgery is a Johnson & Johnson (New Brunswick, New Jersey) company.

• GI Dynamics (Lexington, Massachusetts), a developer of non-surgical, endoscopic approaches for the treatment of Type 2 diabetes and obesity, said that its EndoBarrier Gastrointestinal Liner was highlighted by leading experts in metabolic disorders and endoscopy at DDW.

"This is proving to be a very successful year for GI Dynamics and our development efforts in support of the EndoBarrier," said CEO Stuart Randle. "Based on the data we have seen to date, we believe EndoBarrier, as part of a multidisciplinary approach, has the potential to dramatically change the treatment paradigm for Type 2 diabetes and weight problems due to its unique profile as a non-surgical and non-pharmaceutical treatment option.

"Notably," he said, "EndoBarrier may provide the benefits of gastric bypass surgery without the complications and risks associated with a highly invasive procedure, and unlike traditional pharmaceutical approaches, our implantable device removes the burden of dose regimen compliance from the patient."

The EndoBarrier Gastrointestinal Liner is placed in the GI tract endoscopically (via the mouth) to create a barrier between food and the wall of the intestine. The company said physicians believe that preventing food from coming into contact with the intestinal wall may alter the activation of hormonal signals that originate in the intestine, thus mimicking the effects of a Roux-en-Y gastric bypass procedure without surgery.

It said a "growing body of pre-clinical and clinical evidence supports the potential for EndoBarrier Gastrointestinal Liner to dramatically change the treatment landscape for people living with Type 2 diabetes, obese people at risk for Type 2 diabetes, and people with severe weight problems."