Chicago-based medical device firm Attune Medical’s ensoETM is being evaluated in numerous ongoing clinical studies to investigate device efficacy in reducing thermal injury to the esophagus during cardiac ablation procedures, a common treatment for atrial fibrillation. The ensoETM device is FDA cleared for whole body temperature management using the esophageal space, but it has not been cleared by the FDA for reduction of thermal injury to the esophagus.
Cardiac ablation utilizing radiofrequency energy or cryoablation is used to restore normal heart rhythms in patients with atrial fibrillation by disrupting faulty electrical pathways that interfere with normal sinus rhythm. It is the most common type of cardiac ablation procedure, with nearly 250,000 per year performed in the US and EU alone.
The risk of complications related to cardiac ablation procedures is generally low, although certain risks are associated with high levels of mortality, such as injury to the esophagus, which occurs in approximately 15-40 percent of cases. A much smaller percentage of these (~0.25% incidence) can progress into atrioesophageal fistula (AEF), which is fatal in up to 80 percent of cases. Esophageal thermal injury (ulceration) is likely the initial injury that leads to AEF formation and can take 2-4 weeks to progress clinically, making diagnosis difficult.
A standard safety method often used to mitigate this type of injury is a luminal esophageal temperature (LET) probe that measures internal esophageal temperature changes during application of ablation energy but does not protect against actual injury formation, as energy must penetrate the esophageal wall to reach the temperature sensor. If temperature sensors increase to a dangerous level, typically practitioners will stop the ablation until temperature readings return to normal, albeit often after tissue injury has already occurred. In addition, if temperature sensors are not positioned close to the site of ablation, practitioners may be unable to accurately detect the relevant temperature increases needed to prevent an advancing injury.
Complicating matters, symptoms of esophageal injury may not be observed until weeks after the procedure, and most patients are discharged home after only an overnight stay. When injury does occur, symptoms are typically vague in nature, including fever, fatigue, malaise, chest discomfort, nausea, vomiting, dysphagia, odynophagia, hematemesis, melena, and dyspnea.
There are currently no proven strategies to prevent esophageal injury, and injury rates have not declined despite the use of temperature probes, warranting further investigation into safety measures. Several ongoing clinical studies are currently recruiting patients to investigate current prevention tools and effective mitigation strategies beyond current practice, including studies on the ensoETM.
“Attune Medical is proud to support key studies around the world designed to evaluate new strategies to improve patient safety during cardiac ablation,” commented Attune Medical CEO Keith Warner. “We believe that the opportunity for ensoETM to mitigate potential injury, whether from radiofrequency or cryoablation energy, is of increasing interest and we look forward to the final results of these studies.”
Attune Medical has developed proprietary medical device technology that simplifies access to the patient’s core to efficiently control temperature and is the only device FDA-cleared for use in the esophagus for whole-body temperature management. Attune Medical’s ensoETM is a single use thermal regulating device that is placed in the esophagus (similar to a standard orogastric tube) and connected to an external heat exchange unit, creating a closed-loop system for heat transfer to increase or decrease patient temperature. Its placement in the esophagus, with proximity to blood flow from the heart and great vessels, allows highly efficient heat transfer. Unlike surface warming devices, ensoETM‘s internal placement doesn't impede patient access during surgery and allows gastric decompression and administration of fluids and medications. The ensoETM device is used in critical care units, operating rooms, and emergency departments for the intentional modulation of patient core temperature and can be rapidly placed by most trained healthcare professionals.