Valley Heart & Vascular Institute - David Procedure and Aortic Root Surgery
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David Procedure and Aortic Root Surgery

David Technique David Technique

The ‘David’ Technique

The ‘David Procedure’ is a specialized procedure for aneurysms of the ‘aortic root’: the very first segment of aorta that immediately exits the heart. The aortic root is special in that it contains both the aortic valve, as well as the origins of the coronary arteries. When an aneurysm is located in the root, it is impossible to treat the aneurysm without also doing ‘something’ with the valve and coronary origins.

Click here to see a David Procedure performed at The Valley Hospital.

Most centers would perform a procedure called a ‘Bentall’ operation, which replaces the root aneurysm as well as the aortic valve, regardless of whether or not there is anything wrong with the valve. This is done either with a mechanical valve (necessitating life-long treatment with a blood thinner called Coumadin) or a biological valve (with an expected durability of around 10-15 years before re-replacement is needed). In a ‘Bentall’, valve replacement is carried out even if the valve itself is not diseased, and functioning perfectly well.

Dr. Tirone David (University of Toronto) conceived of this more advanced procedure, also called ‘valve-sparing aortic root replacement’ or ‘aortic valve re-implantation’, where the patient’s aortic valve is extensively dissected from its attachments, and literally re-implanted into the aneurysm replacement graft. Not only has this approach been found to be as durable as mechanical valves at 15 years of follow-up, severely leaking (regurgitant) aortic valves can be made to be competent (eliminates leaking) as part of the valve re-implantation. This is a procedure typically reserved for younger patients, who would not want to be on life-long anticoagulation with Coumadin, and whose life expectancy should exceed that of a tissue (animal) valve.

We have performed this surgery at Valley in patients aged up to their young 70’s, depending on their overall risk profile for surgery. The TABAV Program at Valley Hospital has the largest active experience with this important procedure in our area, outside of New York City. For more on why aortic valve preservation may be preferable to replacement, link to the Aortic Valve Repair (AVr) page.

Certain patients with root aneurysms may not be candidates for the David Procedure. If the aortic valve itself is not healthy, it should not be preserved or re-implanted. While even a severely leaking valve is not a contraindication, calcification of the valve often is. Some imaging studies, especially echo, might suggest that a particular valve is calcified when it is not. The misinterpretation might be due to valve leaflet thickening, particularly common in bicuspid aortic valves (BAVs). When the valve is not suitable for re-implantation, either based on patient age and co-morbidities, or due to anatomic features, the valve is removed, and a traditional aortic root replacement is performed. This can be accomplished in a variety of ways, but all methods will have some things in common: the aortic root aneurysm is removed from the body, the origins of the two main coronary arteries are sewn to the replacement graft, and a new valve is implanted. The valve replacement may comprise pig, cow, or horse tissue, or a mechanical (metal) valve. In general, we favor tissue valves, with a preference for a strategy that avoids the need for life-long anticoagulation with Coumadin. Our typical approach to the biological Bentall Procedure is to use a commercially available 'full' porcine (pig) aortic root replacement. In this arrangement, the entire pig aortic root (including the valve, aorta and coronary artery origins) has been removed from the animal and processed as an off-the-shelf product. The main advantage of this approach is that the valve will continue to experience 'normal' shear stresses after implantation, since the dimensions of the aortic root tissue that 'live' with the valve are physiologic, and perfectly matched to the valve. This means less wear and tear over the years, and better long term durability. In addition, this is considered a 'stentless valve', meaning that, since it is not reconstructed over metal and cloth, there is no extraneous material to narrow any aspect of how the valve opens, and this leads to very large valve opening areas, meaning less strain on the left ventricle, which is better for heart function over time. Aortic root surgery continues to be a major focus of our practice.

For more information, please call Ellen Oehrlein, RN, BSN-BC, at 201-447-8398 or e-mail eoehrle@valleyhealth.com.

 
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