Aortic root anatomy

Anatomy of the aortic root
By Dr. Mohamed A. Gabr
Mansoura University

1. MCTS DEP. RESIDENT
2016

2. The aortic root connects the LV to the systemic circ.
Each component of the aortic root has an optimalstructure and
anatomical architecture which contributes to the function of the
aortic root:
-unidirectionalchanneling of large volumes of fluid,
-maintaining laminar flow, minimal resistance during varying
haemodynamicconditions and demands.

3. The aortic root consists of distinct entities:
1-the aortic valve leaflets,
2-the sinusesof Valsalva,
3-the sinotubularjunction,
4-the aortic annulus

4. 1-Aortic valve leaflets
The three leaflets form the aortic valve and provide its main sealing mechanism.
Anatomicallythe valve leaflets can be divided into threeparts:
-The free margin, with a thickened circular node (nodulusArantii), which provides
the coaptationarea to the corresponding neighboring valve leaflets
On either side of each nodulusis an extremely thin, crescent-shaped portion of the
cusp termed the lunula
-The “belly”of the leaflet
-The leaflet attachments

5. 2-Sinuses of Valsalva
Three sinuses host the origin of the coronary arteries and
the sinuses are termed accordingly the left, rightand non-coronary sinus.
-limited proximallyby the attachments of the valve leaflets
-limited distallyby the sinotubular junction.

6. The precise functionof the sinuses of Valsalva is unclear.
There is evidence that “the vortices” created in the sinuses
lead to:
-stress reduction on the aortic leaflets and
-support coronary flow.

7. The interleaflettriangles
Undereachcommissureliesoneofthethreeinterleaflettriangles.
Although histologicallythey consistof thinned aorticwall,
-hemodynamicallytheyareextensionsoftheventricularoutflowtractandreachthe
levelofthesinotubularjunctionintheareaofthecommissures.

8. The triangle between the right-and non-coronary sinuses
-facesthe right atrium.
-It is in direct continuity with the membranous septum proximally
-containsthe His bundle.
Clinical importance:
-This area is of special importance during aortic valve procedures, as
injury here can lead to temporary or permanent conduction abnormalities

9. Under the left and non-coronary triangle,
the aorto-mitral curtain leads to the anterior leaflet of the mitral valve.

10. 3-Sinotubular junction
The distal part of the sinuses toward the ascending aorta together with the commissures
form a tubular structure called the “sinotubular junction”
-which separates the aortic root from the ascending aorta.
Clinical importance:
In some cases dilatation of the sinotubular junction is the cause of central aortic
insufficiency and replacement of the ascending aorta with a short tubular graft can
restore valve competence.

11. 4-The “annulus”
The ‘hemodynamic ventriculo-arterial junction’
-represented by the coronet shaped leaflet insertion,
-defines the separation level of ventricular and arterial hemodynamics.
The ‘anatomic/histologic ventriculo-arterial junction’
-represented by the transition plane between the ventricular and aortic walls