Aortic root anatomy DR NIKUNJ R SHEKHADA (MBBS,MS GEN SURG,DNB CTS SR)

1. ANATOMY OF AORTIC ROOT
BY DR NIKUNJ
(CTS RESIDENT STAR HOSPITAL)
(Coordinator:DR P.SATYENDRANATH PATHURI)
(4/7/18)

3. AORTIC ROOT
• The aortic root is the anatomic segment
between the left ventricle and the
ascending aorta. It contains the aortic
valve and other anatomic elements,
which function as a unit. The aortic root
has several anatomic components:
• subcommissural triangles,
• aortic annulus,
• aortic cusps,
• aortic sinuses or sinuses of Valsalva,
• sinotubular junction.

5. THE SUBCOMMISSURAL TRIANGLES
• The subcommissural triangles are
part of the left ventricular out
fow tract, but they play an
important role in the function of
the aortic valve.
• The subcommissural triangles of
the noncoronary aortic cusp are
fibrous extension of the
intervalvular brous body and
membranous septum, whereas
the subcommissural triangle
beneath the left and the right
aortic cusps is an extension of the
muscular interventricular septum.

6. THE AORTIC ANNULUS
• The aortic annulus, a fibrous structure with a scalloped shape, attaches the aortic
valve to the left ventricle.
• It is attached directly to the myocardium in approximately 45% of its
circumference, and to fibrous structures in the remaining 55%
• The diameter of the aortic annulus is 10% to 20% larger than the diameter of the
sinotubular junction of the aortic root in young patients . As the number of elastic
fibers in the arterial wall decreases with age, the sinotubular junction dilates, and
its diameter tends to become equal to that of the aortic annulus in older patients.

7. • With dilation of the aortic annulus, the subcommissural triangles of the
noncoronary cusp tend to become more obtuse as the crescent shape of the aortic
annulus along its fibrous insertion flattens.

10. CUSPS
• The normal aortic valve has three cusps. Each cusp has a semilunar shape and has
a base and a free margin. The base is attached to the aortic annulus in a crescent
fashion. The point at which the free margin of a cusp joins its base is the
commissure, and
• the ridge in the aortic wall that lies immediately above the commissures is the
sinotubular junction.
• The free edge of each cusp is tougher consistency than the remainder of cusp.
• At the mid point of each free edge is fibrou nodulus arantii on either side of
nodulus is extremely thin.
• The free margin of an aortic cusp extends from one of its commissures to the
other. The length of the free margin of an aortic cusp is approximately 1.5 times
the length of its base.

11. CUSPS
• The three aortic cusps often have different sizes
in a person, and the right and noncoronary cusps
are usually larger than the left cusp.
• The same cusp may have different sizes in
individuals with the same body surface area
• During diastole, the free margins and part of the
body of the three cusps touch each other
approximately in the center of the aortic root to
seal the aortic orifice.
• Thus, the average length of the free margins of
three aortic cusps must exceed the diameter of
the sinotubular junction to allow the cusps to
coapt centrally and render the aortic valve
competent .

12. • If a pathologic process causes shortening of the length of the free
margin of a cusp, or if the sinotubular junction dilates, the cusps
cannot coapt centrally, resulting in aortic insufciency .
• If the length of a free margin is elongated, the cusp prolapses, and
depending on the degree of prolapse, aortic insufficiency ensues

13. AORTIC SINUSES, OR SINUSES OF VALSALVA
• The spaces contained between the aortic
annulus and the sinotubular junction are the
aortic sinuses. There are three cusps and three
sinuses:
• left cusp and sinus,
• right cusp and sinus,
• noncoronary cusp and sinus.
• The left main coronary artery arises from the
left aortic sinus, and the right coronary artery
arises from the right aortic sinus.
• There are three sinuses of the aortic valve, each
related to the valve’s corresponding cusps. Each
sinus is divided into three areas a central part
and two adjacent parts, which are named
according to the valve cusps they adjoin.
• The noncoronary sinus is also refferred to as
the posterior aortic sinus.

14. AORTIC SINUSES, OR SINUSES OF VALSALVA
• The aortic sinuses facilitate closure of the aortic valve by creating eddies and
currents between the cusps and arterial wall .
• They also prevent the cusps from occluding the coronary artery orifices during
systole, thus guaranteeing myocardial perfusion during the entire cardiac cycle.

16. RIGHT CORONARY SINUS
• entire right coronary sinus lies adjacent
to the RVOT.
• central part lies adjacent to the crista
supraventricularis,
• left part is adjacent to the area of the
RVOT in the angle between the crista
supraventricularis and the pulmonary
valve.
• posterior (noncoronary) part of the
right coronary sinus is related to the area
of the right ventricle posteroinferior to
the crista supraventricularis.
• Inferiorly, the entire right coronary sinus
is related to the interventricular septum;
the muscular septum lies under the
central and left parts, while either
membranous or muscular septum may
lie under the posterior part of the right
coronary sinus.

17. NONCORONARY SINUS
• The atrialchambers with the
intervening atrial septum lie adjacent
to the noncoronary sinus.
• right and central parts of the
noncoronary sinus are related to the
right atrium and the interatrial septum,
• left part is related to the left atrium.
• Inferiorly, the right part, like the
posterior part of the right coronary
sinus, may be related either to the
membranous or the muscular septum
depending on the size of the
membranous septum. However,
beneath the central part of the
noncoronary sinus, the membranous
septum is a constant structure. The left
part of the noncoronary sinus inserts
into the anterior mitral leaflet

19. LEFT CORONARY SINUS
• posterior part of the left coronary
sinus shares the same relationship as
the left part of the noncoronary sinus,
that is, it is related to the left atrium
posteriorly and to the anterior mitral
leaflet inferiorly.
• central part of the left aortic sinus is
the only part of the aortic root that is
not related to a cardiac chamber; it is
adjacent to the epicardium only.
• right part of the left coronary sinus
lies adjacent to the pulmonary trunk
at the level of the left pulmonary
sinus. inferior to it lies the muscular
interventricular septum.

22. • The aortic root of young individuals is elastic and very compliant. It expands and
contracts during the cardiac cycle.
• The normal aortic root has a fairly consistent shape, and the sizes of the cusps, the
aortic annulus, the aortic sinuses, and the sinotubular junction are somewhat
interdependent.
• Thus, large cusps have a proportionally large annulus, sinus, and sinotubular
junction.

23. THANK YOU

24. The ascending aorta
• The ascending aorta begins at the distal
extremity of the three aortic sinuses, the
sinotubular junction, which lies at the line
of opening of the free edge of the leaflets
of the aortic valve.
• It runs its short course passing superiorly
obliquely to the right, and slightly forward
toward the sternum. It is contained within
the fibrous pericardial sac, so its surface is
covered with serous pericardium. Its
anterior surface abuts directly on the
pulmonary trunk, which is also covered
with serous pericardium.
• the ascending aorta is related
anteromedially to the right atrial
appendage, and posterolaterally to the
right ven-tricular out flow tract and the
pulmonary trunk.
• Extrapericardially, the thymus gland lies
between it and the sternum.

25. The ascending aorta
• The medial wall of the right atrium,
the superior caval vein, and the right
pleura relate to its right side.
• On the left, its principal relationship is
with the pulmonary trunk.

26. The arch of the aorta
• The arch of the aorta begins at the
superior attachment of the pericardial
reflection just proximal to the origin of
the brachiocephalic artery
• It continues superiorly briefly before
coursing posteriorly and to the left,
crossing the lateral aspect of the distal
trachea and finally terminating on the
lateral aspect of the vertebral column.
• Here it is tethered by the parietal pleura
and the arterial ligament.
• During its course, it gives off the
brachiocephalic, the left common
carotid, and the left subclavian arteries.
•

27. • The descending, or thoracic, aorta continues
from the arch, running an initial course lateral to
the vertebral bodies and reaching an anterior
position at its termination. It gives off many
branches to the organs of the thorax throughout
its course,