May 4, 2010 Endoscopic radiofrequency ablation is an effective treatment in eliminating Barrett's esophagus, an electronic "nose" offers a fast and effective way to detect inflammatory bowel disease, artificial replacements are now being developed to replace gastrointestinal tissue that is removed, and researchers find that endoscopic ampullectomy for treating ampullary adenoma (tumors of the bile duct) is more precise than surgery with fewer side effects. These are among the studies being presented at Digestive Disease Week® (DDW®) 2010. DDW is the largest international gathering of physicians and researchers in the field of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.
"Advancements in technology are changing the face of medicine daily," said Kenneth K. Wang, MD, FASGE, AGAF, Mayo Clinic College of Medicine Rochester, MN. "With every development we are able to diagnose and treat illness more effectively and at an earlier stage."
Endoscopic Radiofrequency Ablation for Barrett's Esophagus: Five-Year Durability Outcomes from a Prospective Multi-Center Trial (Abstract #358)
Barrett's esophagus (BE), a condition that may lead to esophageal cancer, can often be eliminated using radiofrequency ablation (RFA) and most patients remain free of BE five years following initial procedure, according to a new study from the Mayo Clinic. These findings may lead to changes in the current recommendations of constant surveillance of BE for progression into esophageal cancer. About one in 200 patients with the earliest form of Barrett's develop esophageal cancer each year, one of the fastest growing cancers.
In this prospective, multi-center trial conducted from May 2004 to November 2009, researchers performed endoscopic RFA, designed to burn away the abnormal Barrett's cells, in patients with intestinal metaplasia. For 50 RFA patients in whom BE had been eliminated at the two and a half year assessment, endoscopy was performed at five years. Results showed that 46 of the 50 remained free of BE, and four patients had low levels of residual disease that was eliminated in a single RFA session.
"We've shown that by treating patients with early Barrett's we were able to eliminate the disease in most instances, and we hope that will lead to a reduction in the cancer associated with it," said David Fleischer, MD, staff physician at Mayo Clinic in Arizona. "RFA represents a durable, long-term approach to treating Barrett's esophagus and restoring cells to normal."
BE is a complication of acid reflux that affects mostly Caucasian males over the age of 50. BE occurs when the esophagus is burned by stomach acid causing normal cells to resemble cells from the stomach or intestine. Normally this disease progresses in stages: from the initial stage of metaplasia to low grade dysplasia, high grade dysplasia and cancer. National recommendations for BE in its early stages suggest monitoring the disease progression with regular endoscopies.
Dr. Fleischer points out that there are some limitations to surveillance for patients with Barrett's. Surveillance as a primary strategy has not been shown to be cost-effective and some patients who have followed recommended surveillance strategies are diagnosed with esophageal carcinoma despite undergoing surveillance. In addition, recommendations assume that the endoscopist takes the requisite number of biopsies and information suggests that the requisite number of biopsies is not always taken.
Dr. Fleischer and colleagues will continue to follow patients to assess continued durability of the procedure. He cautioned that no therapy is perfect, but RFA technology is exciting and the results to date encouraging.
This study was funded by BARRX Medical Inc.
Dr. Fleischer will present these data on Monday, May 3 at 4:48 p.m. CT in Ballroom C, Ernest N. Morial Convention Center.
The Gut in Health and Disease: Scenting the Difference by "Electronic Nose" (Abstract #T1267)
Researchers have developed a simple, quick and effective instrument that allows them to detect the existence of inflammatory bowel disease (IBD) by using an "electronic nose." It distinguishes ulcerative colitis from Crohn's disease, and these in turn from normal subjects. The device recognizes the bio-odorant signature characteristic of the condition.
Investigators collected urine samples from healthy volunteers as well as those with ulcerative colitis and Crohn's disease; five patients from each cohort were then analyzed using a Cyrano A320 detection device which uses chemical sensors that create a "fingerprint" of the total chemical composition of a sample. Each was sampled for 30 seconds and purged for 30 additional seconds in laboratory air, and then the differential response between the sample and background air was used to analyze the specimen. The result was that the device was able to distinguish between disease groups based on their gaseous profile from urine samples.
"This gives a new insight into the nature of IBD, and in time may allow us to identify the disease at an earlier, more treatable stage," said lead investigator Ramesh P. Arasaradnam, MD, gastroenterology consultant and senior lecturer at the University of Warwick in England. "This could prevent patients from having to undergo invasive procedures." He added that the test results may be able to help clinicians select the most appropriate treatment.
Investigators hope to develop the tool to be able to distinguish where patients are on the pathway of treatment. Additionally, researchers hope to devolve the instrument into a portable device that can be carried or used by anyone in a clinical setting, gives results that are easy to interpret, does not require very specialized or high power computers, and if affordable. Right now they are using a prototype that will need to be refined to be used on a regular basis.
Dr. Arasaradnam will present these data on Tuesday, May 4 at 8 a.m. CT in Hall F, Ernest N. Morial Convention Center.
Hybrid Transvaginal NOTES Cholecystectomy Using a Novel Flexible Toolbox and Internal Retraction System (Abstract #604)
In a video presented at DDW, researchers from Northwestern University's Fineberg School of Medicine demonstrate the use of novel surgical instrumentation designed to overcome challenges with available tools, specifically creating a stable platform, methods of internal retraction and instruments for dissection. Researchers show the functionality of these tools in hybrid transvaginal NOTES® cholecystectomy procedures to remove the gallbladder through the vagina.
Natural Orifice Translumenal Endoscopic Surgery® (NOTES) is a surgical technique performed via an endoscope passed through a natural orifice, or opening, in the body. NOTES reduces the need for incisions and may allow for less pain and scarring associated with traditional laparoscopic surgery along with a much faster recovery time for the patient. Over the past several years, NOTES has been expanded to include more procedures, but more advanced surgical instruments are necessary to improve the efficiency and safety of these procedures. Most of the tools currently used were originally designed for standard endoscopic procedures.
"Right now we're limited by some of our equipment. We need specifically designed instruments to continue to move this field forward," said Eric S. Hungness, MD, FACS, assistant professor of surgery, Feinberg School of Medicine at Northwestern University. "Designing more optimal equipment may translate to greater efficiency and safety, less pain, better recovery and less invasive surgery for patients."
Several tools demonstrated in the video are being evaluated in a feasibility trial under an investigational device exemption from the FDA. The trial may pave the way for a specific NOTES indication for surgical devices. Other devices used, including a laparoscopic device, are FDA commercially-available devices.
Dr. Hungness will present these data on Tuesday, May 4 at 10 a.m. CT in 255-257, Ernest N. Morial Convention Center.
Efficacy of an Electrosurgical Endo-Knife with a Water-Jet Function for Colorectal Endoscopic Submucosal Dissection of Superficial Colorectal Neoplasms (Abstract 347i)
By comparing the results of large colorectal tumor removal via endoscopic submucosal dissection (ESD) with flexknife versus flushknife, researchers from Osaka Medical Center for Cancer and Cardiovascular Diseases in Japan have discovered that flushknife, an endoscopic device with a water jet function, is a superior tool for removing large colorectal tumors (>2cm) in one piece.
Removal of large colorectal tumors by conventional endoscopic resection (EMR) is difficult, so typically such tumors have been removed in fragments through this method or patients have undergone colorectomy. Endoscopic submucosal dissection (ESD) is a promising new endoscopic therapy that can remove large tumors in one piece. To ensure precise histological assessment and the removal of all tumor residue, removing tumors in one piece is preferable to removing them piecemeal.
While ESD is less invasive than colorectomy, it is a technically difficult procedure to perform, has a higher incidence of complications and requires a longer operation time than conventional EMR. Yoji Takeuchi, MD, of the department of gastrointestinal oncology at the Osaka Medical Center for Cancer and Cardiovascular Diseases sought to determine whether the flushknife could reduce the operation time without increasing adverse effects. He also wanted to determine whether the device could reduce the difficulty of the ESD procedure, thereby making it more accessible for patients.
Dr. Takeuchi and colleagues enrolled 49 patients with superficial colorectal neoplasms in their study and randomly assigned them to undergo ESD using either the flushknife or the flexknife (an electrosurgical endo-knife without a water-jet function). They found that the flushknife enabled them to rinse mucus and blood clots and to inject saline into the submucosa during the procedure, which is an important step in avoiding perforation of the colon during ESD.
"The flushknife is clearly a superior tool to use in performing ESD," said Dr. Takeuchi. "However ESD continues to be a very difficult procedure that not every endoscopist can perform. Further developments are needed for colorectal ESD to become the standard procedure for large colorectal tumor removal."
Dr. Takeuchi will present these data on Tuesday, May 3 at 10:54 a.m. CT in 280-282, Ernest N. Morial Convention Center.
Development of an Artificial Gastric Wall Using Bioabsorbable Polymer (Abstract #439o)
Researchers from Saitama Medical University in Saitama, Japan, have developed a ground-breaking material that can repair and regenerate the gastric wall without deforming the stomach or disrupting GI function. The material, an implanted bioabsorbable polymer (BAP) patch, has been shown to preserve normal GI function after GI surgery in animal models.
Currently available surgeries to remove abnormal tissue growth in the stomach are highly effective, but involve partially removing portion(s) of the stomach, leaving the stomach deformed and/or with decreased GI function. Investigators developed an implantable BAP patch to serve as an artificial gastric wall to allow removal of defective stomach tissue without impairing function or biology of the organ. The BAP patch is composed of a 50:50 copolymer of polylactic acid and polycaprolactone reinforced with polyglycolic acid fibers and designed to degrade about six to eight weeks after implantation. Investigators evaluated the technique in 15 hybrid pigs.
To evaluate the efficacy of the BAP patch, researchers accessed the stomach through an incision in the abdominal wall, removed an 8x8 cm. portion from the front stomach wall and replaced it with the patch. At four, eight and 12 weeks following implantation, the implanted area was examined in total and histological, or cell-level, assessments.
All of the subjects survived the evaluation period without decreases in fluid or food intake. At four to eight weeks following implantation, the implantation site showed daily reduction of the patch. At 12 weeks, the implantation site was nearly indistinguishable from the original gastric wall in appearance. A closer look confirmed the growth of mucosa and submucosa, two of the innermost layer of the gastric wall, and a muscle layer similar to the original wall. Subtle differences between the artificial and original wall were confirmed in the connective tissue, including somewhat reduced amounts of elastic fiber and smooth muscle density compared to the original gastric wall.
"Currently, the surgical options available for treatment of gastric diseases and stomach tumors are disabling," said Mitsuo Miyazawa MD, PhD, professor in the department of surgery, Saitama Medical University. "This technique has potential as a novel treatment to repair a defective GI tract while preserving full GI function."
The investigators plan to study the gastric function and preservation of organ shape with the BAP patch over a longer period of time. They also plan to investigate the patch's use in the small and large intestines.
Miyazawa cautioned that while these results are promising, the treatment must still be tested in humans in a clinical trial within a global cooperative structure.
Dr. Yasuko Toshimitsu, MD, PhD will present these data on Tuesday, May 4 at 4:30 p.m. CT in 292, Ernest N. Morial Convention Center.
Complex Laparoscopic Procedures Can Be Safely Performed Early in Fellowship Training (Abstract #T1647)
A new study from the Carolinas Laparoscopic and Advanced Surgery Program at Carolinas Medical Center in Charlotte, NC, found that performance of advanced laparoscopic procedures in a minimally invasive surgery program is safe, regardless of whether the surgery is performed early or late in fellowship training.
These findings contradict previous research, which has suggested that receiving medical care early in the academic year may carry more risk than at other times. Because some of the surgical techniques for advanced laparoscopic procedures are not learned in general surgery residency and additional training is required, it might be thought that surgical outcomes may be worse during the first few months of the academic year as new trainees arrive.
Researchers sought to look at the outcomes and efficiency of the procedures performed in a fellowship setting, including length of operation, amount of bleeding, complications, and length of hospital stay, to determine whether any significant differences existed between the early and later training months. They analyzed outcomes from the early (July to September) and late (March to May) academic year and found the time periods to be equally safe. The so-called "July Effect" has been studied at medical training institutions in both surgery and general medicine, but in regards to advanced surgical training with newer and more complex approaches, it has not been previously reported.
Researchers reviewed all operative and post-operative data from the fellowship program (established 1999) during the identified months when a fellow was participating in a complex operation -- in this case a laparoscopic Heller Myotomy -- and determined if either time period was associated with poorer results. This relatively rare surgery involves a delicate dissection of certain layers of the esophagus in a less commonly encountered region for general surgeons (the national average for esophageal surgery cases for graduating residents in 2009 was five, and this included anti-reflux procedures). In this study period, 54 such cases were performed in the assigned time periods.
Paul Montero, MD, Fellow at Carolinas Laparoscopic and Advanced Surgery Program at Carolinas Medical Center, said the study should comfort the patient who needs elective complex laparoscopic surgery at a training institution in the early part of the academic year. "The study demonstrates that an apprenticeship model with graduated responsibility in an academic surgical program can result in safe and effective operative outcomes while giving high quality training," Dr. Montero said. "In an era of advancing technology, potential shortages of surgeons, and work-hour restrictions, this finding is very important as we continue to train new surgeons."
Dr. Montero cautioned that the study focuses on a single training institute and a single, complex laparoscopic procedure, and although the same surgeons at the Carolinas Medical Center have drawn similar conclusions when analyzing other complex laparoscopic procedures such as colon resection and paraesophageal hernia repair, but the finding of equally safe outcomes in the early versus late academic year cannot be applied to all complex surgeries or all surgical training centers.
Dr. Montero will present these data on Tuesday, May 4 at 8 a.m. CT in Hall F, Ernest N. Morial Convention Center.
Ampullectomy: Long Term Results of a Large Multicenter Prospective Study (Abstract #788f)
New research from the French Society of Digestive Endoscopy (SFED) demonstrates the long term efficacy of endoscopic ampullectomy for treating ampullary adenoma, early tumors of the small muscle located at the junction of the common bile duct (carrying bile from the liver and secretions from the pancreas) into the upper small intestine. Endoscopic ampullectomy was found to be more precise than surgery and resulted in fewer side effects and lower patient morbidity.
Researchers, among them Thierry Ponchon, MD, professor of medicine at the Centre Hospitalier Universitaire de Lyon, completed a large prospective multicenter study of endoscopic ampullectomy in 93 consecutive patients from September 2003 to January 2006. Patients were included in the study if they had positive biopsies (at least adenoma), and no previous ampullectomy or laser treatment. Endoscopic ampullectomies were conducted by 11 experienced endoscopists using a side-viewing endoscope under sedation. If pathological examination of the resected area was different from the initial biopsies, a second look was performed by an experienced pathologist.
To determine the effectiveness of the procedure, patients were followed-up between four and eight weeks, undergoing a complementary resection if necessary. Patients were then followed up with at six, 12, 18, 24 and 36 months with systematic biopsies. The procedure was considered curative if the resection was complete, no submucosal carcinoma was observed, control of the cancer was normal at six months and no relapses were observed during follow up period.
Researchers observed an 80 percent rate of success in patients, and a 95 percent success in analyzable patients. Sixty-eight patients with complete resection had a follow-up: 57 had normal 36-month control and were considered cured; three had incomplete follow-up, asymptomatic but without control; five died of other diseases; and three had a tumor recurrence at 12 and 24 months.
"Our study demonstrates that endoscopic ampullectomy is an effective alternative to surgery for the treatment of ampullary adenoma," said Dr. Ponchon. "Given excellent preoperative preparation, this treatment is less invasive and more precise than surgery for resecting the ampulla."
Dr. Ponchon cautioned that endoscopic ampullectomy is a difficult procedure that should only be performed by experienced endoscopists. Additionally, it should not be performed for invasive adenocarcinoma of the ampulla because the endoscopy has a risk of being incomplete.
Dr. Gincul from SFED will present these data on Tuesday, May 4 at 3:15 p.m. CT in 280-282, Ernest N. Morial Convention Center.
Digestive Disease Week® 2010 (DDW®) is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery. Jointly sponsored by the American Association for the Study of Liver Diseases, the AGA Institute, the American Society for Gastrointestinal Endoscopy and the Society for Surgery of the Alimentary Tract, DDW takes place May 1 -- May 5, 2010 in New Orleans, LA. The meeting showcases more than 5,000 abstracts and hundreds of lectures on the latest advances in GI research, medicine and technology.
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