Aorto-Right Ventricular Tunnel in Transposition of the Great Arteries

Aorto-ventricular tunnel with three orifices: a unique case report diagnosed by transthoracic echocardiography

BACKGROUND

Aorto-ventricular tunnel (AVT) is an abnormal communication channel between the ascending aorta and the ventricle. It commonly has two orifices, i.e., one aortic opening and one ventricular opening. In this study, we present a unique case of AVT with three orifices: one aortic opening, one LV opening, and one RV opening.

CASE PRESENTATION

A 64-year-old male presented with chest discomfort and dyspnea on exertion lasting the past six months. Physical examination revealed a grade 4/6 continuous biphasic murmur along the left sternal edge and a grade 3/6 systolic murmur at the apex. Transthoracic echocardiography (TTE) demonstrated: (1) an AVT with three orifices, i.e., one aortic opening, one LV opening, and one RV opening. The LV and RV openings were located in the left and right ventricular outflow tracts, respectively. (2) The aortic valve (AV) was calcified with a small aneurysm at the non-coronary cusp. (3)The mitral valve (MV) chordal rupture of the P2 and P3 segments was observed in the posterior leaflet with severe eccentric regurgitation. Subsequent coronary computed tomography angiography (CTA) further confirmed the diagnosis of AVT with three openings, and clarified the coronary arteries normally arose from the aortic sinuses. The patient was then referred for surgical treatment, consisting of closure of three AVT orifices, AV replacement, and MV replacement. Six months following surgery, the patient was asymptomatic. TTE demonstrated normal mechanic AV and MV function, and there was no residual shunt among the ascending aorta, LV and RV.

CONCLUSIONS

It is the first case to report an AVT with three orifices. This paper described the entire process from diagnosis to treatment of this unique case, thus providing some novel insights into AVT.

A Review of the Surgical Management of Aorto-ventricular Tunnels

We present a synthesis of 95 published investigations of the exceedingly rare tunnels that can exist between the aortic root and the left or right ventricles. From the 220 suitable cases included in these investigations, we reviewed the clinical presentations, modalities used for diagnosis, surgical approaches, and outcomes. Diagnostic information was provided by clinical presentation, radiographic findings, saline contrast echocardiography, computed tomographic angiocardiography, magnetic resonance imaging, cardiac catheterization, and angiocardiography. These techniques elucidated the coronary arterial origins and associated defects and defined the disease before surgery. Patients occasionally present with an asymptomatic cardiac murmur and cardiomegaly, but most suffer cardiac failure in the first year of life when the tunnel enters the left ventricle. Antenatal diagnosis by fetal echocardiography is reliable after 18 weeks of gestation. Associated defects, involving the proximal coronary arteries or the aortic or pulmonary valves, are present in nearly half the cases. Prompt diagnosis and surgical repair are important for a favorable outcome. Overall, operative mortality has been cited to be between 3% and 8.3%. Associated congenital coronary arterial anomalies, residual severe aortic stenosis, poor left ventricular function, and rupture of an infected suture line have been the reported causes of death. Despite early surgical intervention, an incidence of 16% to 60% postoperative residual aortic regurgitation of varying severity has been reported. The requirement of further repair or replacement of the aortic valve ranges from 0% to 50%. We submit that an increased appreciation of these details relative to the tunnels will contribute to improved surgical management.

Prenatal Diagnosis of Aorto-Left Ventricular Tunnel With Dysplastic Bicuspid Aortic Valve: From Fetal Cardiac Failure to Favorable Outcome

Aorto-left ventricular tunnel (ALVT) is a rare congenital heart defect. Surgery has to be performed early to avoid life-threatening complications. Prenatal diagnosis of this defect is challenging. We report a case of ALVT diagnosed in a fetus showing premature severe cardiac failure at 24 GA. The new born was operated at day 3 of life with good results. Two years later, he is still doing well recovering a complete normal cardiac function. ALVT should be suggested in front of any fetal cardiac failure. Thanks to early diagnosis, prompt neonatal management can be organized and allows positive outcome.