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Detection of Esophageal Injury <br />
After AF Ablation
January 2008
Is PillCam ESO and the Given Imaging System also currently used for gastroenterology procedures?
Yes, PillCam ESO was developed for patients suffering from esophageal disorders, such as esophageal varices, which may result in fatal bleeding, and Barrett s esophagus, which is an early indication for esophageal cancer. It provides a patient-friendly alternative to esophageal endoscopy and the associated sedation and discomfort. PillCam ESO contains an imaging device and light source at both ends of the capsule and takes up to 14 images per second a total of 2,600 color images as it passes down the esophagus.
What made you decide to use this for identification of RFA-related esophageal injuries?
Our rationale for using esophageal imaging after ablation therapy for atrial fibrillation (AF) was the potential for esophageal injury with energy used during the ablation procedure. The proximity of the esophageal wall to the area that is ablated in the heart may result in transmural injury of esophagus, leading to discomfort, and, more seriously, development of atrial-esophageal fistula (although this is encountered very rarely).
Recently an article by Drs. Natale and Saliba1 raised awareness of this complication; they both were instrumental in the initiation of esophageal imaging in their patients, in an effort to improve care and identify patients at possible risk for development of serious complications after the ablation procedure.
How long has esophageal capsule endoscopy been available?
PillCam ESO received FDA approval in November 2004 and received a permanent CPT ® Code by the American Medical Association and the Center for Medicare and Medicaid Services effective January 1, 2007.
How is this technology used? Describe how the PillCam ESO and the Given Imaging System are used during a procedure to look for atrial fibrillation ablation related esophageal injury.
The patient fasts for two hours, then swallows the PillCam ESO video capsule with a glass of water while lying on his or her back. After swallowing PillCam ESO, the patient is raised by 30-degree angles every two minutes over a six-minute ingestion period, until he or she is sitting upright. The total procedure takes approximately 20 minutes and can be performed in the doctor's office, hospital, or clinic. Natural digestive contractions help propel the disposable PillCam ESO through the GI tract. It is passed naturally and painlessly from the body, usually within 24 to 72 hours.
How soon can esophageal capsule endoscopy be used after atrial fibrillation ablation to look for ablation-related injury?
The patient needs to be fully awake to participate in the test. The test can be performed and interpreted the same day, after the ablation is performed. In our proposed trial design, most patients will have capsule endoscopy within 24 hours of ablation.
What methods, if any, are currently used to diagnose RFA-related esophageal injury?
There is no consensus or guidelines currently. Two methods that can be used at this time are esophagogastroduodenoscopy (EGD) and capsule endoscopy. However, in my opinion, capsule endoscopy is more suited for this due to its simplicity. In addition, with capsule endoscopy, results are readily available, there is no need for an endoscopy room and staff, and the patient does not need additional sedation during the procedure. EGD with insuflation of the esophagus could be potentially hazardous if transmural injuries of the esophageal wall predispose the patient to esophageal perforation.
How many AF patients were tested using this technology? Were there any adverse reactions?
Our preliminary results suggest that esophageal injury happen in patients (we identified positive ESO findings in 7 out of 32 total patients). None of our patients developed AE fistula or any long-term complications in the esophagus. We used our findings to identify and follow these patients more closely for extended periods of time. Patients were also treated with proton pump inhibitors in order to facilitate the healing of mucosa and eliminate additional damaging effects of gastric acid.
Is this technology currently used only by gastroenterologists, or could it also be used by electrophysiologists in the future?
All endoscopic images should be interpreted by board-certified gastroenterologists. Tests can be performed in any setting with appropriate medical staff, and images/video can be electronically transferred to the central reading site where board-certified gastroenterologists will interpret the study and communicate the results back to the cardiologist. However, except for the Cleveland Clinic, no one is currently using this technology.
What future studies are being planned to test its use in the electrophysiology lab?
This was just a small pilot study designed to see if this imaging approach was adequate in this particular indication. We are encouraged with the results and will proceed with a larger trial soon. One of the goals of the larger trial will be to better understand endoscopic characteristics of the lesions in the esophagus and to eliminate preexistent lesions. Therefore, in the trial design we will have patients ingest a capsule before and after the ablation, so the true frequency of ablation-related lesions can be assessed. Once post-ablation esophageal lesions are better defined (which we hope to achieve with this trial), esophageal capsule endoscopy could be used after ablation procedures to identify the patients at risk of serious complications.
Dr. Walid Saliba and I are principal investigators on the upcoming study sponsored by Given Imaging, where we will be looking into the utility of the ESO capsule in evaluation of esophageal injury after ablation. This trial, entitled the CEPELA trial (Capsule Endoscopy in Postablation Esophageal Lesion Assessment), is in final phases of preparations; we are expecting it to start by the end of January. The CEPELA trial will assess the presence of preexisting lesions and relative frequency of ablation-related injuries, focus on follow-up of patients with the injury, and assess if capsule endoscopy of the esophagus is a valid method for monitoring these patients.
Is there anything else you'd like to add?
The advantages of capsule imaging compared to regular esophagoscopy in this particular indication are: 1) no air insuflation, which can potentially precipitate perforation in the event of transmural esophageal injury; 2) no need for sedation, as capsule endoscopy is well-tolerated by most patients; and 3) the procedure can be done (capsule can be administered) at the ablation center(s), then video can be transmitted (as an digital file) for analysis to a certified gastroenterologist, minimizing the patient's need to go from one department (center) to another and increasing overall efficiency of delivered care.
Contraindications for this procedure are described in the device insert, and include the inability to swallow, presence of a cardiac pacemaker or defibrillator, history of bowel obstruction, etc. A full list can be reviewed in the manufacturer s package insert.