New Device Uses Radiofrequency Energy for PFO Closure

Newswise — Today, exciting results from the first-ever human trial of a new device that uses radiofrequency energy to close a patent foramen ovale (PFO), a flap-like opening between the upper chambers of the heart, were presented by Marijke Skowasch from the CardioVascular Center Frankfurt at the Cardiovascular Research Foundation's (CRF) Annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium, in Washington, D.C. PFO closures have been successfully performed for more than 10 years using catheters to insert permanent devices to seal a PFO; however the U.S. Food and Drug Administration has limited their use for specific, life-threatening situations.

A patent foramen ovale usually closes after birth in 80% of adults; however, for one in five adults, the PFO does not seal completely and blood moves directly from the right atrium to the left atrium, bypassing the filtering system of the lungs. In such instances, if debris such as blood clots are present in the blood, they can pass through the left atrium and lodge in an artery in the brain -- causing a stroke -- or in another organ, such as the heart, eyes, or kidneys. This can lead to recurrent strokes or temporary loss of brain function. The PFXâ„¢ Closure System is designed to fuse the opening using low radiofrequency energy, without the need for permanent implantable devices that carry significant risks.

"Tissue welding using radiofrequency energy as a means of repairing soft tissue injuries and surgical lesions has been the subject of medical research for decades," said the lead investigator, Horst Sievert, Cardiovascular Center, Frankfurt, Germany. "Our initial experience with this unique application for PFO closure has been very exciting, and we look forward to additional research that will lead to broader uses for this promising device."

In this study, 29 patients underwent the procedure with the PFX Closure System under local anesthesia. The PFX catheter was guided into the right upper chamber (atrium) of the heart, a vacuum was used to pull the ends of the septum together, and radiofrequency energy was applied to fuse them together. In 26 out of 29 patients, the procedure was performed successfully. Immediate, complete closure was achieved in 17 of the 26 patients treated with the PFX system. Thirty day follow-up results for the most recent subset of subjects has demonstrated 4 of 5 were successfully closed. No complications or device related adverse events were observed during or after any of these procedures. One patient in whom the procedure was not successful has gone on to safely receive treatment with a standard implant device.

According to Marijke Skowash, "This initial experience suggests that the PFX Closure System is a technically feasible, safe and effective method that provides several benefits, including elimination of the risks associated with implantable devices."

About the PFXâ„¢ Closure SystemThe PFX Closure System (Cierra, Inc., Redwood City, California 94063 USA) consists of a disposable catheter, a power supply and a vacuum pump. The catheter device is advanced over a guide wire from the right femoral vein, and contains housing that positions itself over the PFO in the right atrium only. Once the housing is in place, the vacuum is applied to pull the tissues of the PFO tunnel together, and RF power is applied. Power is monitored until the tissues of the PFO are fused together and closure of the PFO is achieved. The catheter is then removed. Total procedure time is 20-40 minutes.

Because the procedure is performed entirely from the right atrial side, potential complications of left atrial catheterization are eliminated. In addition, nothing is implanted within the PFO tunnel that can cause patency, or continued leakage.

About CRF and TCTThe Cardiovascular Research Foundation is dedicated to research and education in the broad subspecialty of interventional cardiology and endovascular medicine. By establishing the safe use of new technologies and pharmacologic agents, CRF has played a major role in the remarkable advances in survival and quality of life for patients with cardiovascular disease. CRF is the sponsor of the 17th Annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium, one of the largest interventional vascular medicine meetings in the world. For more information, please visit http://www.crf.org.