**3. Aortic root pathology**

*Cardiac Surgery Procedures*

touching the aortic wall [8].

subsequent clinical sequelae [9].

The dilated portion of the aortic wall between the aortic annulus and sino-tubular junction is known as the sinus of Valsalva. These sinuses are named according to the relationship of the origin of the coronary ostia from the root that is left, right or non-coronary sinuses. The sinuses are labelled corresponding to their coronary ostia. One of the important roles provided by these sinuses is preventing obstruction of the coronary ostia during movement of the aortic valve leaflets against the aortic wall, so that coronary blood flow is maintained [5]. An important function is prevention of ostial obstruction during systole when the aortic valve is open [7]. Generation of Eddy currents during early systole prevents the aortic leaflets from

*Opened aortic root section. Sinotubular junction is indicated by the open arrows, small arrows indicating the coronary ostia (left and right), broken lines indicating the fibrous skeleton between the aortic and mitral* 

*valves. L, R, and N mark the left, right and the non-coronary cusps, respectively [6].*

The aortic valve leaflets which are inserted at their bases in a semilunar fashion to the aortic annulus. They allow uni-directional flow of blood from the left ventricle to the aorta. Aortic valve leaflets are variable in size and number, the noncoronary cusp being the largest compared to the left or right aortic valve cusps. The most common variation is the bicuspid aortic valve, which consists of a semi-lunar opening due to the presence of two leaflets, and the commonest deviation from the normal tri-leaflet pattern is the known congenital anomaly called bicuspid aortic valve [9]. The attachment of the curved aortic valve leaflets form the triangular space named as the interleaflet triangles, the apices of these triangles is known as the valve commissures which are at the level of the sinotubular junction [10]. Aortic valve competence depends on the overlap between these adjacent free margins of

The aortic valve annulus represents the ventriculo-aortic junction which is a complex structure and universally accepted term as aortic annulus [9]. The basic attachments of the aortic valve leaflets at the aortic annulus comprise muscular and fibrous parts [5]. The right aortic valve leaflet attaches to both the membranous and the interventricular septa, while the non-coronary leaflet attaches to the membranous septum and the fibrous skeleton of the anterior mitral valve leaflet, and the left aortic valve leaflet attaches to the fibrous skeleton of the anterior mitral valve leaflet and partly to the interventricular septum [9]. Connective tissue disorders that involve the fibrous skeleton of the aortic root lead to alteration in normal geometry. Damage begets further damage leading to significant valve distortion and

**36**

the leaflets.

**Figure 1.**
