The Normal Aortic Valve

The aortic valve has a deceivingly simple design. However, its macroscopic anatomy must be understood in relation to its function. This understanding also has a repercussion on the surgical treatment of aortic valve disease. A supporting structure of a valve prosthesis does not necessarily follow the line of attachment of the native leaflets.

The aortic root has to be defined properly. It is more than just a ring in a two dimensional plane. The attachment of the valvular leaflets possesses a three dimensional structure which changes in shape during the cardiac cycle.

The aortic annulus also needs full description. The diameters at the level of the STJ, the mid-sinusal level and the anatomic AVJ are part of this concept.

The microscopic and cell biological description of the aortic valve include

- The layers within the leaflets.

- The cells.

o Endothelial cells or EC and their function.

o Valvular interstitial cells or VIC and their function.

- The extracellular matrix.

o The fibers: collagen and elastin.

o The glycosaminoglycans or GAG.

A thorough description of these elements is needed for understanding of:

- The durability of the native valve during an entire human life span.

- The understanding of pathological processes.

- The construction of tissue engineered heart valves or TEHV.

Keywords: Aortoventricular junction, bone morphogenetic protein, collagen, endothelial cells, extracellular matrix, fibrosa, glycosaminoglycans, left ventricular outflow tract, nitric oxide, sinotubular junction, spongiosa, valvular interstitial cells, ventricularis.