Q&A with Todd M. Dewey, M.D.
Southwest Cardiothoracic Surgeons, North Dallas LIVING WELL Magazine
Aortic Valve Replacement
As a pioneer in the field of aortic valve replacement using a catheter-based system that does not require the use of a heart lung machine, stopping the heart or opening the chest, Dr. Dewey has the distinction of performing the first transapical aortic valve replacement utilizing this breakthrough technology in the United States. He is recognized as one of the most experienced surgeons in the world with this technique. Internationally known as a leader in the field of valvular heart disease, he has trained surgeons in Europe, Canada, Australia and the United States in both catheter-based aortic valve replacement and minimally invasive surgical techniques.
Q: What is the aortic valve?
A: The aortic valve is one of the four valves of the heart. There are two valves that separate the upper and lower chambers of the heart (the mitral and tricuspid valves) and two valves that separate the heart from the rest of the body (the aortic and the pulmonary valves). The aortic valve normally has three leaflets, although 1 to 2% of the population is born with only two leaflets. A normally functioning aortic valve opens easily and does not let blood leak back into the heart when it closes.
Q: What is the most common problem with the aortic valve?
A: Aortic stenosis is the most common problem with the aortic valve, and the most common reason for valve-related heart surgery. Stenosis, or narrowing of the valve, occurs when calcium builds up on the valve and limits its ability to open when the heart contracts. The normal opening of the aortic valve is roughly the size of a half-dollar, but severely narrowed valves have an opening the size of a dime. Approximately 2% of people older than 65 years of age, 3% of people 75 and older, and 4% of people older than 85 have aortic valve stenosis. However, the prevalence is increasing with the aging population in North America and Europe.
Q: What are the symptoms of aortic stenosis?
A: Initial symptoms are mild fatigue or shortness of breath with exertion. As the stenosis progresses and worsens, patients may develop fainting with rapid standing, lower extremity edema, chest pain, shortness of breath while at rest, and ultimately death unless it is treated.
Q: How is aortic stenosis treated?
A: Typically aortic stenosis is treated with open-heart surgery to completely replace the narrowed valve. The most common type of valves used to replace abnormal aortic valves are either bovine or porcine in origin. These types of valves do not require the use of blood thinners. In medical centers with extensive experience in aortic valve surgery, most patients are treated with a minimally invasive approach that decreases patient discomfort and promotes early return to activity.
Q: Are there any new minimally invasive techniques to treat aortic stenosis?
A: Percutaneous aortic valve replacement is being performed at the leading cardiac surgical centers around the world—including advanced centers located here in North Texas, such as Medical City Dallas. This new technique does not require opening the chest, stopping the heart or using the heart-lung machine to replace the aortic valve. The valve can be inserted through either an artery in the leg or a small incision between the ribs. This new valve is currently FDA approved for use in patients too old or sick for conventional surgery and likely to receive FDA approval in the near future for higher-risk patients with critical aortic stenosis.
SERVICES PROVIDED BY DR. DEWEY:
Structural Heart Disease
• Aortic Valve Replacement
• Transcatheter Aortic Valve Implantation
• Mitral Valve Repair and Replacement
• Tricuspid Valve Repair
• Aortic Dilatation/Aneurysm Repair Resection
• Subaortic Hypertrophic Septum
• Atrial Septal Defects
• Ventricular Septal Defects
• Anomalous Pulmonary Vasculature
• Ventricular Aneurysms
• Cardiac Tumors
Coronary Heart Disease
• Coronary Artery Bypass Grafting
• Endoscopic Conduit Harvest
• ‘On and Off Pump’ Technique
• Hybrid approach in conjunction with cardiologist
Heart Failure Surgery
• Orthotopic Heart Transplantation
• Left Ventricular Assist Devices
• HeartMate II®
• Duraheart™
• HeartMate XVE®
Carotid Artery Surgery
• Endovascular Repair of Aorta
• Abdominal
• Thoracic
