Two-dimensional echocardiographic identification of aortico-left ventricular tunnel

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.

Aorto-Right Ventricular Tunnel in Transposition of the Great Arteries

Aorto-ventricular tunnel is an extremely rare congenital heart defect, consisting of failure of attachment of an aortic leaflet along the semilunar hinge. In all published reports the leaflet involved was either the right coronary leaflet, most frequently, or the left coronary leaflet, in most of the cases opening toward the left ventricle, with only one-eighth of the reported cases communicating with the right ventricle. Treatment of the aorto-ventricular tunnel has been anecdotally reported by interventional closure with a device and more frequently with surgical approach, either as an isolated malformation or as associated lesions. To the best of our knowledge, the presence of an aorto-ventricular tunnel of the non-adjacent aortic leaflet in transposition of the great arteries has never been reported. We have observed an aorto-ventricular tunnel involving the non-adjacent leaflet of the aortic root, which after arterial switch became the pulmonary root. The patient presented 18 years after the arterial switch with progressive dilatation of the right ventricle due to severe degree of pulmonary valve regurgitation, confirmed by echocardiography and cardiac MRI. Indication for surgery was given with the plan for a pulmonary valve implantation. Because of the intra-operative finding of disconnection of the anterior leaflet of the pulmonary valve (former aortic valve) along the semilunar hinge, the surgical plan was modified and the anterior leaflet was attached to the valve annulus, with subsequent plasty in correspondence with the right and left commissurae to reduce the size of the dilated annulus to normal diameter. The post-operative course was uneventful, with extubation after few hours and discharge 4 days after surgery, with echocardiography showing trivial degree of pulmonary valve regurgitation. The patient remains in good conditions 6 months after surgery.

Aorto-ventricular tunnel

Aorto-ventricular tunnel is a congenital, extracardiac channel which connects the ascending aorta above the sinutubular junction to the cavity of the left, or (less commonly) right ventricle. The exact incidence is unknown, estimates ranging from 0.5% of fetal cardiac malformations to less than 0.1% of congenitally malformed hearts in clinico-pathological series. Approximately 130 cases have been reported in the literature, about twice as many cases in males as in females. Associated defects, usually involving the proximal coronary arteries, or the aortic or pulmonary valves, are present in nearly half the cases. Occasional patients present with an asymptomatic heart murmur and cardiac enlargement, but most suffer heart failure in the first year of life. The etiology of aorto-ventricular tunnel is uncertain. It appears to result from a combination of maldevelopment of the cushions which give rise to the pulmonary and aortic roots, and abnormal separation of these structures. Echocardiography is the diagnostic investigation of choice. Antenatal diagnosis by fetal echocardiography is reliable after 18 weeks gestation. Aorto-ventricular tunnel must be distinguished from other lesions which cause rapid run-off of blood from the aorta and produce cardiac failure. Optimal management of symptomatic aorto-ventricular tunnel consists of diagnosis by echocardiography, complimented with cardiac catheterization as needed to elucidate coronary arterial origins or associated defects, and prompt surgical repair. Observation of the exceedingly rare, asymptomatic patient with a small tunnel may be justified by occasional spontaneous closure. All patients require life-long follow-up for recurrence of the tunnel, aortic valve incompetence, left ventricular function, and aneurysmal enlargement of the ascending aorta.

Congenital Heart Surgery Nomenclature and Database Project: aortico-left ventricular tunnel

The extant nomenclature for aortico-left ventricular tunnel is reviewed for the purpose of establishing a unified reporting system. The subject was debated and reviewed by members of the STS-Congenital Heart Surgery Database Committee and representatives from the European Association for Cardiothoracic Surgery. Efforts were made to include all relevant nomenclature categories using synonyms where appropriate. The Hovaguimian classification appears most useful to surgeons: type 1, a simple tunnel with a slit-like opening at the aortic end, no aortic valve distortion; type II, a large extracardiac aortic wall aneurysm of the tunnel with an oval opening at the aortic end, with or without ventricular distortion; type III, intracardiac aneurysm of the septal portion of the tunnel, with or without right ventricular outflow tract obstruction; and type IV, a combination of type II and III. A comprehensive database set is presented, which is based on a hierarchical scheme. Data are entered at various levels of complexity and detail, which can be determined by the clinician. These data can lay the foundation for comprehensive risk stratification analyses. A minimum database set is also presented which will allow for data sharing and would lend itself to basic interpretation of trends. Outcome tables relating diagnoses, procedures, and various risk factors are presented.

Echocardiographic-anatomical correlations in aorto-left ventricular tunnel

OBJECTIVE

To investigate the echocardiographic, morphological, and histological appearances of aorto-left ventricular tunnel observed in four fetal hearts and compare the findings with those reported in older patients with the malformation.

BACKGROUND

Previous studies have concentrated on clinical features of the malformation from birth to adult life and have speculated on either its embryological formation or its acquisition during late intrauterine life. The presentation of a large series of cases in fetal life is a unique opportunity to study the malformation at an early stage in its natural course.

METHODS

A retrospective study was performed of four cases of aorto-left ventricular tunnel discovered among 872 cases of congenital abnormalities diagnosed at a tertiary centre for fetal echocardiography. Detailed echocardiographic and anatomical observations were made of the malformation as identified during fetal life. The precise anatomical arrangement was determined and compared with previous descriptions found in journals published in English.

RESULTS

In fetal life, as after birth, the malformation is characterised by enlargement and hypertrophy of the left ventricle, enlargement of the aortic root, and free regurgitation at the level of the aortic valve. Anatomical abnormalities are found at the aortic ventriculoarterial and sinutubular junctions as well as in the intervening aortic wall. These are unrelated to necrosis, ischaemia, or the presence of mucopolysaccharides.

CONCLUSIONS

The lesion is a developmental abnormality that should be reliably diagnosed by fetal echocardiography combined with colour flow Doppler echocardiography during the mid-trimester. The exact anatomical relations clarified by this study are pertinent to diagnosis and subsequent surgical correction.

Aortico-left ventricular tunnel associated with critical aortic stenosis in the newborn

Aortico-left ventricular tunnel is a rare congenital malformation. A unique case of critical aortic stenosis in a neonate accompanying aortico-left ventricular tunnel is described. Successful surgical correction was performed without invasive studies following echocardiographic recognition of the defect.

Aortico-left ventricular tunnel: long-term outcome after surgical repair

Over a 14 year period, four children (three male, one female) underwent surgical correction of an aortico-left ventricular tunnel. All presented in infancy (age range 5 days to 9 months). The presenting feature was a systolic and diastolic murmur in all, one of whom developed heart failure within 2 weeks of presentation. In the first two patients, the echocardiographic findings were inconclusive and the diagnosis was confirmed at cardiac catheterization (at 10 and 23 months of age, respectively); the other two were diagnosed echocardiographically by two-dimensional and Doppler color flow imaging. All four patients underwent surgery by patch closure of the aortic end of the tunnel (three patients) or direct suture closure (one patient) and there were no deaths. The mean age at operation was 11 months. During a mean follow-up period of 71 months (range 2 to 157), three patients have clinical and echocardiographic evidence of trivial aortic valve regurgitation, which was noted in the immediate postoperative period in one and at early (less than 6 months) follow-up study in the other two. All are symptom-free, are taking no medications and are growing and developing normally. Aortico-left ventricular tunnel can be accurately diagnosed by echocardiography. In patients presenting in infancy, echocardiography also provides the necessary morphologic information to enable surgical correction without angiography. Early operation is associated with an excellent outcome, whereas repair at a later age is associated with a high incidence of residual aortic regurgitation requiring further surgery.

Aortico-right ventricular tunnel and critical pulmonary stenosis: diagnosis by two-dimensional and Doppler echocardiography and angiography

An infant with aortico-right ventricular (AO-RV) tunnel and critical pulmonary stenosis presented with severe distress at birth. We present the clinical, echocardiographic, and angiographic features, correlated with autopsy findings. Also we discuss the differentiation from other AO-RV communications and a theory for the embryogenesis. AO-RV tunnel should be considered in the differential diagnosis of a critically sick newborn with cyanosis, a "to and fro" murmur, and signs of right heart failure. The correct diagnosis can be made echocardiographically by demonstrating the two ends of the tunnel connecting the aorta and a dilated RV, two normal coronary arteries, and obtaining high-velocity systolic and diastolic Doppler flow signals in the tunnel. Surgical repair of this lesion is possible, and early diagnosis and a modification of the surgical procedure may help survival.

Aortico-left ventricular tunnel: diagnosis based on two-dimensional echocardiography, color flow Doppler imaging, and magnetic resonance imaging

Aortico-left ventricular tunnel is a rare congenital cardiac lesion that often results in severe aortic insufficiency in infancy. In previously reported cases, the diagnosis has often been missed initially despite use of cardiac catheterization and angiography. We describe a patient who underwent successful surgical correction of this malformation at 10 months of age after the diagnosis had been established by use of two-dimensional echocardiography, color flow Doppler imaging, and magnetic resonance imaging. Aortico-left ventricular tunnel can be diagnosed by use of these noninvasive means without cardiac catheterization.