Article Type : Case Report
Authors : Yildirim AI, Karaagac AT, Usta SA and Erolu E
Keywords : Atrioventricular Septal Defect; Pulmonary valve syndrome
Absent pulmonary valve syndrome (APVS), defined as the
absence or hypoplasia of the pulmonary valve, stenosis of the pulmonary valve
annulus, and aneurysmal dilatation of the pulmonary trunk and its branches, is
rare congenital heart disease with an incidence of 0.2%-0.4%.
Absent pulmonary valve syndrome (APVS), defined as the
absence or hypoplasia of the pulmonary valve, stenosis of the pulmonary valve
annulus, and aneurysmal dilatation of the pulmonary trunk and its branches, is
rare congenital heart disease with an incidence of 0.2%-0.4% [1,2]. It is
commonly classified into two types: The first type shares many similarities
with tetralogy of Fallot (TOF), including a ventricular septal defect,
overriding aorta, and absent ductus arteriosus, so is called TOF-type APVS. The
other less common type with an intact ventricular septum, a mild degree of
pulmonary artery dilatation, and a patent ductus arteriosus is also called
non-TOF-type APVS [3]. This congenital anomaly may be associated with other
cardiac pathologies, but its association with atrioventricular septal defect
(AVSD) is extremely rare. Apart from heart complications, APVS has a poor
prognosis mostly due to the aneurysmal dilatation of the pulmonary trunk and
its branches, which can compress the bronchus and esophagus, leading to
nutritional and respiratory complications [3,4].
A 3-month-old full-term female infant with Down
syndrome was accepted to our hospital with the signs of respiratory infection.
She had been hospitalized several times with signs of respiratory distress
before being accepted to our hospital. On her physical examination, she had
tachypnea, tachycardia, bilateral crepitant and subcrepitant rales, 3/6
systolic murmur along the mid-left sternal border on auscultation, and a 3-4 cm
palpable liver below the right lower costal margin. Her laboratory findings
were normal except for moderately increased acute phase reactants and mild
anemia. The electrocardiogram showed left axis deviation and sinus tachycardia.
Cardiomegaly and prominent pulmonary vascular bed were observed on her chest
roentgenogram. The transthoracic echocardiography revealed unbalanced complete
atrioventricular septal defect (AVSD), left ventricular hypoplasia, secundum
type atrial septal defect (ASD), absent pulmonary valve, and pulmonary arterial
aneurysm (Figure 1).
On her computed thorax tomography, pulmonary annulus was 8 mm and bifurcation was observed. The pulmonary arteries were enlarged, the right pulmonary artery was 23 mm and the left one was 16 mm in diameter, thus applying compression on both right and left main bronchi. Besides, bilateral subsegmental atelectasis and mosaic perfusion pattern were observed due to the effect of pressure (Figures 2 and 3).
Figure 1: Echocardiographic imaging of atrioventricular septal defect, left ventricular hypoplasia, atrial septal defect, and absent pulmonary valve.
Figure 2: Torax CT image showing the compression of enlarged pulmonary arteries on the pulmonary bronchi.
Figure 3: Thorax CT image showing
the effect of compression on pulmonary parenchyma.
Dilatation was detected in the proximal esophagus as a
result of the left pulmonary arterial compression. A transcatheter angiography
was performed after her respiratory infection was treated. Angiography
confirmed the absence of pulmonary valve leaflets and revealed a 90 mmHg
gradient across the pulmonary valve annulus with a mean pulmonary arterial
pressure of 19 mmHg.
Our patient, who was a candidate for a single ventricle
operation due to the unbalanced AVSD, underwent pulmonary banding and surgical
plication as the first stage operation. She didn’t experience any
post-operative problems and was discharged with the planning of the Fontan
procedure following a Glenn operation at the most convenient time for her. She
has been followed successfully for 5 months.
APV is defined as a syndrome because it is associated
with cardiac (tricuspid atresia-intact septum, absent aortic valve-intact
septum, Ebstein's anomaly, tetralogy of Fallot, interrupted aortic arc),
extracardiac (CHARGE association, agenesis of corpus callosum, duodenal
atresia, bilateral renal agenesis) or chromosomal (trisomy 13, trisomy 18,
trisomy 21, 22q11 deletion) anomalies [5,6]. Respiratory distress and infection
are common in these patients due to the compression of the bronchial tree by
aneurysmatic dilatation of the pulmonary arteries [7]. Our patient had
tachypnea, tachycardia, bilateral crepitant and subcrepitant rales, 3/6
systolic murmur along the mid-left sternal border on auscultation, and a 3-4 cm
palpable liver below the right lower costal margin on admission. She had
trisomy 21 and AVSD, a very rare association with the absent pulmonary valve,
free pulmonary valve insufficiency, and accompanying severe annular artery
aneurysm on cardiologic evaluation. Two main types of APVS have been described
in the literature as TOF type, associated with the ventricular septal defect,
overriding aorta, and absent ductus arteriosus, and non-TOF type [3]. Our case
differed from these two classifications because it was accompanied by an
unbalanced AVSD. The anatomic data required for pre-operative evaluation of
patients with atrioventricular septal defect and/or absent pulmonary valve
syndrome may be confidentially obtained by transthoracic echocardiography [5].
In our case, unbalanced complete atrioventricular septal defect, left
ventricular hypoplasia, secundum type atrial septal defect, absent pulmonary
valve, and pulmonary arterial aneurysm were highly suggestive of absent
pulmonary valve syndrome, but the rarity of the association prompted cardiac catheterization.
Angiocardiography confirmed the absence of pulmonary leaflets and the mean
pulmonary arterial pressure was measured before surgery. The prognosis of APVS
is poor mainly due to the extra cardiac complications resulting from
compression of pulmonary bronchi and esophagus. In addition to medical
treatment of cardiac and respiratory pathologies, various methods for
pilication of the absent pulmonary valve, surgical reduction of a pulmonary
aneurysm, and pulmonary valve repair are applied for the surgical management
[4-10]. In the study of Young et al. early mortality rate was reported as 13,5%
and 5-10-20 year average late mortality rate as 6,7% in the 52 postoperative
APVS patients [11]. In the present case, due to the presence of unbalanced AVSD,
pulmonary banding and pilication operation was performed initially. The patient
was discharged in good health. Glenn and Fontan surgeries will be planned in
the most suitable time during her follow-up.