Prenatal Diagnosis of Congenital Absence of Aortic Valve: A Report of Two Cases with Different Outcomes and a Literature Review

Abstract

Congenital absence of aortic valve (AAV) is a rare cardiac anomaly associated with high mortality. We present 2 prenatally diagnosed cases of AAV. In both cases, fetal echocardiography showed no aortic valve tissue and free aortic regurgitation. At 24 weeks' gestation, case 1 showed a hypoplastic hypocontractile left ventricle and mitral atresia, but did not develop hydrops and was born at term. Bilateral pulmonary arterial banding was performed with continuous infusion of prostaglandin E₁ at 5 days of age followed by Norwood and bidirectional Glenn procedures at 3 months of age. The hypoplastic non-compliant left ventricle and mitral atresia might have limited aortic regurgitation. Case 2 showed hydrops at 23 weeks' gestation. An enlarged hypocontractile left ventricle and massive mitral insufficiency were noted. The regurgitant flow was directed to the right atrium through a foramen ovale. This peculiar hemodynamic established a malignant circuit which was arbitrarily called ‘inverse circulatory shunt'. Intrauterine death occurred at 28 weeks' gestation. An autopsy showed absent aortic valve leaflets but three tiny membranous remnants. Hemodynamic evaluation by fetal echocardiography should include the documentation of the presence of and assessment of the grade of aortic regurgitation, mitral regurgitation and blood flow through a foramen ovale as well as left ventricular function.

An extremely rare case of prenatally diagnosed absent both aortic and pulmonary valves

“…Congenital absent pulmonary valve (APV) is a rare anomaly occurring in about 0.2% to 0.4% of live born infants with congenital heart disease [ 1 ]. Absent aortic valve (AAV) is a much rarer cardiac anomaly with perhaps no more than two dozen reports in the literature [ 2 ], and a combination of these two conditions is extremely rare [ 3 ].…”

“…A color Doppler image shows a typical to-and-fro pattern of pulmonary stenosis and regurgitation. AAV may also demonstrate left heart dilatation with stenoinsufficiency similar to the characteristics of APV [ 2 ]. However, because of its rarity, prenatal echocardiographic findings have not been well described.…”

First‐Trimester Echocardiographic Features and Perinatal Outcomes in Fetuses With Congenital Absence of the Aortic Valve

“…In one report, a fetus with a hypoplastic left ventricle and mitral atresia survived fetal life to term and underwent bilateral pulmonary artery banding after birth, followed by Norwood and bidirectional Glenn procedures at 3 months of age. 5 Along with hypoplasia of the left ventricle, a stiff left ventricle with elevated end-diastolic pressure may limit the volume of regurgitation across the aortic valve, reducing the physiologic effect of a perfusion steal. In patients with absence of the aortic valve, the noncompliant hypoplastic left ventricle and mitral atresia appear to affect the clinical outcome.…”

“…In most reported cases, the diagnosis was made in the second and third trimesters 3 , 4 . The earliest gestational age at diagnosis was 14 weeks in a fetus with cystic hygroma 5 …”

“…3,4 The earliest gestational age at diagnosis was 14 weeks in a fetus with cystic hygroma. 5 Absence of the aortic valve is not typically an isolated anomaly. In a review of 15 reported cases, hypoplasia of the left heart was seen in 11 cases (73%), a double-outlet right ventricle in 5 (33%), and aortic arch malformations in 6 (40%).…”