CONGENITAL HEART DISEASE
CONGENITAL AORTIC SINUS OF VALSALVA ANEURYSM
AND PROLAPSE
S.E.C. Spitaels, MD Department of Cardiology,
Thoraxcentre, Erasmus Medical Centre Rotterdam,
Rotterdam, The Netherlands
Aortic root pathology is more common than primary
aortic valve disease and accounts for more than
one-half of the patients undergoing valve replacement
(1). In these cases aortic valve insufficiency
results from progressive dilatation of the aortic
sinuses and distortion of the annulus (2). The
most common causes of acquired degenerative disease
leading to dilatation are a normal phenomenon
of ageing, especially in the presence of systemic
hypertension, or “idiopathic”(3). Profound dilatation
of the weakened aortic walls may occur on the
basis of aortic medial necrosis (isolated or in
association with Marfan syndrome), annuloaortic
ectasia and along with rare systemic disorders.
Less common and less known is a rare congenital
disorder due to the presence of a weak point in
the aortic wall resulting from a localized interruption
of the media, that can lead to the typical congenital
aneurysm of the sinus of Valsalva with eventual
rupture (4) or to the syndrome of prolapse of
the right coronary cusp in the presence of a subarterial
doubly-committed ventricular septal defect (5).
In this review we will focus on the congenital
nature of the disease with a short description
of the normal structure of the aortic root, the
pathophysiologic changes that occur in the presence
of a congenital anomaly of the aortic wall, the
clinical presentation, the technique of echocardiographic
imaging and the surgical treatment.
The aortic root is a three-dimensional structure
made up of the sinuses of Valsalva, the leaflets
of the valve and the interleaflet triangles. The
three sinuses of Valsalva occupy the greater part
of the aortic root. They are dilatations of the
aortic wall confined proximally by the bases of
the semilunar valve leaflets and distally by the
sinotubular ridge (6). Inside they provide a hollow
space enclosed by the aortic cusps and the opposite
aortic wall (7). They accommodate the open leaflets
providing space behind them and, as such, preventing
occlusion of the coronary artery orifices. They
allow formation of eddy currents within them,
which prevents the leaflets striking the aortic
wall and promotes valve closure. The sinuses are
named according to their relation with the coronary
artery: the right, the left and the non-coronary.
Alteration in any part of the aortic root will
affect their function. For example: dilatation
of the sinuses, even in the presence of normal
valve leaflets, will prevent coaptation of the
leaflet edges in diastole (8).
The basic congenital abnormality causing an
aneurysmal dilatation of the sinus of Valsalva
is a weak point in the aortic wall due to a localized
interruption of the media. The aneurysm localized
in one aortic sinus, which is not dilated itself,
projects as a finger like extension and has a
perforation at its tip (Figure 1). Rupture rarely
occurs and is seen in the majority of patients
well after puberty. Of these congenital aneurysms,
90 to 95% originate in the right or non-coronary
sinus. Those arising in the right coronary sinus
may rupture into the right ventricle or right
atrium, those arising in the non-coronary sinus
into the right atrium. An aneurysm originating
from the left sinus is an extremely rare finding.
Deformation of the right or non-coronary sinus
of Valsalva is associated with a ventricular septal
defect (VSD) in about 50% of patients (Figure
1). The VSD is small and always situated high
in the ventricular septum. The right sinus of
Valsalva may prolapse through a subarterial doubly
committed VSD (supracristal type) and both the
right and non-coronary sinus through a perimembranous
VSD with extension to the outlet. Characteristic
for the subarterial VSD is the absence of the
outlet septum resulting in fibrous continuity
between the
Fig. 1
Fig. 1. Schematic illustration
of the aortic root with the characteristic appearance
of the sinus of Valsalva (middle), of an aneurysm
projecting into the right atrium (left), of a
right sinus prolapse through a subarterial VSD
(right).
Fig. 2
Fig. 2. Schematic illustration
of hemodynamic factors causing prolapse of right
sinus of Valsalva through the VSD during early
systole (left), late systole (middle) and diastole
(right). The small arrow on the left points to
the discontinuity between the aortic median and
the annulus of the aortic valve. (With permission.
Cardiologie 2000;7:105 Figure 3
aortic and pulmonary valves, which
are situated on the same level. Hence, the upper
margin of the defect is made up by the right coronary
cusp and part of the dilated sinus of Valsalva
and the lower border by the crest of the ventricular
septum with no intervening muscular tissue. Both
sinus of Valsalva aneurysm and subarterial VSD
are more common in the Asiatic population. Not
only the media of the aortic sinus fails to reach
the aortic annulus, but additional failure of
the annulus to attach to the ventricular septum
is present (Figure 2). These basic abnormalities
result in the aortic sinus and annulus in this
region not being supported, causing progressive
changes, which are further aggravated by hemodynamic
factors (5). During early systole a Venturi-effect
is produced by the left-to-right shunt through
the small VSD, displacing the unsupported annulus
outward and downward, with prolapse into the VSD
later in systole. In diastole the high pressure
in the aortic root produces further distension
and displacement towards the right ventricular
outflow-tract. Failure of coaptation of the valve
leaflets, caused by progressive elongation of
the free margin in the right coronary cusp, results
in progressive valve regurgitation and secondary
changes in the form of thickening and retraction
of the free borders of all three cusps2
The clinical picture reflects either
a sudden large perforation or a gradual development
of a small perforation (7). Unruptured aneurysms,
as a rule, do not cause symptoms. With
Fig. 3
Fig. 3. Jugulogram and phonocardiogram
in the presence of rupture into the right ventricle
(left) and into the right atrium (right).
Fig. 4
Fig. 4. Cross sectional echocardiogram.
Parasternal long axis view showing an aneurysm
of the right sinus of Valsalva protruding anteriorly
and caudally in systole (left), obliterating the
VSD in diastole (right).
echocardiography they are now being
diagnosed with increasing frequency. Occasionally
an unruptured aneurysm can cause severe complications
such as: 1) obstruction of the right ventricular
outflow (10); 2) tricuspid stenosis and insufficiency
secondary to prolapse of the aneurysm through
the tricuspid valve (11); 3) conduction abnormalities
due to the proximity of the right coronary cusp
to the common bundle of His and proximal portions
of the right bundle and left anterior fascicle
with several reported cases of complete heart
block (12); and 4) coronary artery compression
or obstruction of the ostium of the right coronary
artery by thrombus within the right sinus of Valsalva
aneurysm (13). Acute large rupture can have a
dramatic onset with severe chest pain, dyspnea
and even pulmonary edema culminating in death
after a short period of time. On the other hand,
a small perforation may initially go unnoticed.
Gradual progression will permit a better hemodynamic
adjustment. Rupture is characterized by the sudden
appearance of a continuous murmur in an otherwise
healthy individual. Either the systolic or the
diastolic portion of the continuous murmur tends
to be louder. The intensity may diminish around
the second sound, to increase again in diastole
creating a to-and-fro impression (4). The association
of a progressively diminishing systolic VSD murmur
with the appearance of a soft diastolic aortic
insufficiency murmur should alert the physician
to the occurrence of a prolapsing aortic cusp
into the VSD. The jugular pulse tracing can be
of help in
Fig. 5
ig. 5. Transoesophageal echocardiogram.
Short-axis view of the aortic valve showing a
sinus of Valsalva aneurysm arising from the non-coronary
aortic cusp and communicating posteriorly and
to the right with the right atrium.
differentiating between a rupture
to the right atrium and to the right ventricle
(Figure 3). In the case of rupture into the right
ventricle, the severe diastolic ventricular volume-overload
causes obliteration of the y-descent indicating
that the ventricle has become so “stiff” that
it is incapable of expanding rapidly in response
to the incoming blood from the right atrium in
early diastole. On the contrary, rupture into
the right atrium obliterates the x-descent. The
high volume of blood shunted into the right atrium
results in an incomplete emptying of the atrium
that fills quickly from above as it begins to
relax, causing it to become rapidly over distended.
The high right atrial pressure promotes early
tricuspid opening with a premature v-wave, and
a high peaked a-wave, associated with a fourth
heart sound.
Echocardiography is the most reliable
method to confirm the diagnosis. Cross sectional
echocardiography and color Doppler allow accurate
recognition and definition of the different components
of the disease. There is no need for diagnostic
catheterization and angiography. The criteria
for the diagnosis of an aneurysm are: (a) the
root of the aneurysm must be located above the
aortic annulus, (b) the aneurysm is saccular,
(c) the size of the aorta above the aneurysm is
normal (14). An aneurysm of the right sinus, communicating
with the right ventricle, protrudes
ig. 6. Schematic representation
of surgical repair using the method of Yacoub
illustrating the sutures placed through the ventricular
crest, the aortic annulus and the sinus of Valsalva.
anteriorly and leftward in a short
axis view, caudally in a parasternal long-axis
view (Figure 4). An aneurysm of the noncoronary
sinus, communicating with the right atrium, protrudes
posteriorly, caudally and to the right (Figure
5). Color flow imaging reveals the shunt from
the aortic sinus into the right atrium or ventricle
and Doppler echocardiography detects a continuous
high velocity flow in the chambers with which
the ruptured sinus communicates. In the presence
of a prolapse of the right coronary cusp the characteristic
dilatation of the right sinus with sagging of
the annulus and cusp into the right ventricle
can be recognized in the parasternal long-axis
view (15). The localization of the VSD is best
visualized in the short axis view: a perimembranous
VSD with extension to the outlet is located between
the midline and the tricuspid valve; a doubly
committed subarterial VSD between the midline
and the pulmonary valve. The characteristic high-systolic
and low-diastolic velocity associated with a left-to-right
shunt through this restrictive VSD can be detected
at the level of the subpulmonary ventricular septum
just below the right sinus of Valsalva in the
parasternal long-axis view and differs from the
continuous high-velocity flow in systole and diastole
after rupture of the aneurysm of the right sinus
(16). In addition the magnitude of aorti regurgigation
can be assessed and right heart pressures estimated.
We favour the policy that any patient
with a subarterial VSD needs regular echocardiographic
follow-up, because of the progressive nature of
the anomalies. Once the characteristic dilatation
of the sinus occurs, there is indication for surgery
even in asymptomatic patients without signs of
prolapse or aortic regurgitation. Some advocate
routine closure of any subarterial VSD as prophylaxis
to prevent aortic valve prolapse. However, this
remains controversial. In the past some surgeons
preferred to approach the aneurysm (and or VSD)
through the cardiac chamber into which it ruptured
(17); others incise the aorta or use a combined
approach. The aneurysmectomy and/or VSD closure
is done directly with sutures or a patch, combined
with repair or replacement of the aortic valve.
More recently, a simple and safe technique was
designed (18). All the anatomic and functional
components of the anomalies, including severe
aortic regurgitation when present, could be corrected
and patch-insertion avoided. Using a transaortic
approach the sutures are placed through the ventricular
crest, aortic annulus and sinus of Valsalva (Figure
6). The continuity between these structures is
restored resulting in closure of the VSD, plication
of the aortic sinus and correction of the outward
and downward displacement of the aortic annulus.
The annulus and the cusp are elevated and displaced
centrally toward the lumen of the aorta, which
has the effect of increasing cusp coaptation.
Yacoub’s technique, at the time of the operation,
was sufficient to restore competence of the aortic
valve in 65% of the patients. In the remaining,
repair of the aortic valve was necessary. Late
aortic insufficiency is still a risk.
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