Novel Occluder Patches Holes in the Heart

A novel catheter technique for patching holes in the heart may make it possible for many patients to avoid surgery altogether and others to regain enough strength to safely undergo surgical repair at a later date, according to a new study.

Researchers at the Mayo Clinic (Rochester, MN, USA) reviewed the medical records of 10 patients treated with aventricular septal defect (VSD) patch between 1995 and 2005. In all cases, the VSD patch was failing, allowing a portion of the blood in the left ventricle to shoot backward into the right ventricle with each heart beat, rather than being circulated to the rest of the body. All patients were implanted with a VSD occluder, and the procedure was successful in all patients, without complications. One patient died five days later of illness unrelated to the VSD patch. In two patients, the rupture did not fully heal, causing damage to blood cells as they jetted through the narrow opening. A third patient developed a bacterial infection that started several months after device implantation. The patch was removed and all three patients had successful surgery to repair the rupture.

After a follow-up that averaged more than one year, patients were feeling markedly better and were much more active, even able to climb a flight of stairs before becoming short of breath. All patients were ranked in New York Heart Association class 2 or better. The study was presented at the 30th annual scientific sessions of the society for cardiovascular angiography and interventions, held during May 2007 in Orlando (FL, USA).

"Patients with acute VSDs may be critically ill with heart failure and perhaps be in cardiogenic shock,” said lead author Matthew W. Martinez, M.D., a cardiology fellow at the Mayo Clinic. "This procedure offers an alternative for patients who are too sick to undergo emergency heart surgery or simply don't want surgery.”

The VSD occluder is composed of two discs connected by a thick shaft. The discs are made of flexible nitinol metal and covered in polyester fabric that encourages heart tissue to grow over them, completely covering them during healing. The flexible double-disc patch is pulled into a catheter, collapsing and compressing it lengthwise. It is then threaded through a vein into the right ventricle and across the rupture into the left ventricle. The patch is pushed partially out of its catheter sheath until the first disc pops open. The catheter is then withdrawn back into the right ventricle, with the first disc positioned against the left ventricular wall and the connecting shaft filling the hole created by the rupture. From inside the right ventricle, the patch is pushed forward again, releasing the second disc, which covers the rupture on the right side of the heart.


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