Ross Procedure Sections: Introduction | History | Anatomy | Pros & Cons | Patient Selection | Technique | Results | Pediatric Ross

Anatomy

The normal structure and orientation of the aortic and pulmonary valves should be explained in order to better understand the Ross operation. As the young fetus develops in utero, the aortic and pulmonary valves emerge simultaneously from the same ridge of budding valve tissue. Prior to birth, the tissue from these ridges will grow into 3 separate leaflets, each shaped roughly like the crescent moon. Thus the nickname "semilunar valves". The normal closure mechanism is designed so that all 3 leaflets simultaneously meet, or coapt, in the middle of the flow channel. Once the valve is closed, blood is prevented from falling backwards into the pumping chamber below. The photograph on the right shows a normal human aortic valve (as seen from above the heart). The valve is nearly closed, with the 3 leaflets meeting in the middle of the flow channel.

The crucial nutrient arteries to the heart muscle (the coronary arteries) arise from the wall of the aorta just above the aortic valve. These small 3 mm blood vessels are critical to survival. No such arteries arise from the corresponding location near the pulmonary valve. One of the key surgical challenges during transfer of the pulmonary valve to the aortic position is the successful reimplantation of the coronary arteries into the autograft. In The Learning Center presentation on the surgical technique, you can see how the surgeon must deal with the coronary arteries during the autotransplant procedure.

The leaflets of both semilunar (i.e. the aortic and pulmonic) valves are attached at their bases to a scalloped ring of tough, dense fibrous tissue at the base of the heart. This ring of fibrous tissue is called the valve annulus. The crest of each leaflet is attached to the wall of the encompassing blood vessel. For the aortic valve, the attachment takes place a centimeter or so above the annulus directly into the walls of the aorta. Similar attachment points are seen in the wall of the pulmonary artery for the 3 leaflets of the pulmonic valve. The location where two leaflets come together at a juncture point is called a commissure. The tri-leaflet semilunar valves (i.e. aortic and pulmonic valves) both have 3 leaflets and 3 commissures.

The main anatomic feature that makes the Ross operation so attractive is the identical physical structure of the two valves. Normal aortic and pulmonic valves are both identical is size, shape and configuration. Both are trileaflet valves with the same semilunar configuration as seen in these photographs. Even when the aortic valve is deformed, the pulmonary valve is almost always created as nature intended. Thus the pulmonary valve provides the closest identical twin possible for the aortic valve. In addition, the pulmonary valve is within a millimeter or two of being the exact right size, is always sterile, and is comprised of living tissue. Since the autograft comes from the same individual, rejection is never a concern. For more on the advantages of using the autograft for aortic valve surgery, please visit to the sections on Patient Selection and the Pros and Cons of the Ross procedure.

Ross Procedure Sections: Introduction | History | Anatomy | Pros & Cons | Patient Selection | Technique | Results | Pediatric Ross

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