Aorto-left ventricular tunnel – prenatal diagnosis and outcome

Purpose Aorto-left ventricular tunnel (ALVT) is an extremely rare, albeit prenatally detectable, extracardiac channel which connects the ascending aorta to the cavity of the left ventricle.

Methods All ALVT diagnosed prenatally (2006-2020) in five tertiary referral centers for prenatal medicine were retrospectively assessed. The diagnosis ALVT was made in fetuses with a paravalvular tunnel bypassing the aortic valve. Focus was on the size of the tunnel, patency of the aortic valve, alterations of the left ventricular outflow tract and the ascending aorta, and the perfusion in the aortic arch.

Results 11 fetuses were diagnosed with ALVT at a mean gestational age of 24.8 weeks. All cases were associated with severe dilatation of the left ventricle and to and fro flow in the left outflow tract. 4 pregnancies were terminated due to progressive severe heart failure and one neonate died of prenatally diagnosed congestive heart failure. One fetus died in utero at 34 weeks without prior evidence of cardiac failure. Of the five survivors, two underwent Ross procedure. In both cases the prenatal left ventricular outflow was exclusively via a large tunnel. The remaining three neonates underwent patch closure of the tunnel. In these cases the prenatal outflow of the left ventricle was via the aortic valve and simultaneously over the tunnel.

Conclusion Prenatal diagnosis of ALVT should be considered in the presence of left ventricular hypertrophy, dilatation of the aortic root and to and fro flow in the aortic outflow tract. Signs of heart failure are associated with unfavorable outcome. Large tunnels, particularly in combination with absence of flow over the aortic valve, may be an unfavorable predictor of surgical repair.

Publication History

Article published online:
20 June 2022