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

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.

Surgical repair of aorto-ventricular tunnel

This report presents a trans-aortic trans-infundibular double-patch repair of an aorto-left ventricular tunnel in a 17-day old male child. It reviews the literature on aorto-ventricular tunnels and debates strategic and surgical options available to correct these defects. Diagnosis of the tunnel in the case described herein was made prenatally. The child was presented with left ventricular dilatation with early and progressive signs of congestive heart failure. Decision for early surgical correction was made considering the quantum of regurgitant jet, diastolic backflow in the aorta and consequent left ventricular dilatation. After establishing cardiopulmonary bypass and arresting the heart, the aorta was transversely opened above the sinotubular junction and the tunnel identified. Aortic valve morphology and the coronary ostia not involved in the tunnel were carefully investigated. Through a transverse infundibulotomy, the thinned outer wall of the tunnel abutting the posterior wall of the infundibular septum was slit open vertically, thus clearly defining the aortic and the left ventricular orifices. The distal tunnel orifice, now presenting as a subaortic Ventricular septal defect (VSD), was closed using a xenopericardial patch and running polypropylene 7-0 stitches. The aortic end of the tunnel was closed in a similar fashion through the aortotomy, remaining clear of the right coronary artery and respecting the aortic valve geometry. The marsupialized wall of the tunnel as seen through the infundibulotomy was sutured with polypropylene stitches. The aortotomy and right ventriculotomy were closed. The postoperative course was uneventful. A follow-up echocardiography at 2 years showed a perfect outcome with no residual tunnel, no aortic stenosis and trivial aortic regurgitation.

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.

Aortico-left ventricular tunnel in fetuses and infants

BACKGROUND

Aortico-left ventricular tunnel is a rare congenital abnormal communication between the aorta and the left ventricle presenting in early childhood as aortic regurgitation and cardiac failure. This condition has rarely been reported in fetuses. Operation is the only treatment, and postoperative aortic incompetence could be related to the age or the type of repair.

METHODS

We conducted a retrospective, two-institution review, from 1983 to 1995, of aortico-left ventricular tunnel diagnosed in utero and before 6 months of age.

RESULTS

Three cases of aortico-left ventricular tunnel were diagnosed in utero by Doppler echocardiography between 22 and 24 weeks' gestation. Prenatal aortico-left ventricular tunnel was associated with severe left ventricular dysfunction, aortic valve anomalies, and fetal hydrops. One death occurred in utero and one immediately after birth, and in 1 case pregnancy was interrupted. In these 3 cases the diagnosis was confirmed by autopsy. Three neonates and 2 infants had the diagnosis of aortico-left ventricular tunnel made after birth and underwent successful surgical repair. At short and midterm follow-up all patients are alive and aortic valve regurgitation is absent or trivial.

CONCLUSIONS

This series shows that aortico-left ventricular tunnel covers an anatomic spectrum of lesions. Cases diagnosed in utero by Doppler echocardiography are characterized by severe ventricular dysfunction, associated aortic valve lesions, and poor outcome. Postnatal cases represent the more favorable end of the spectrum, with no associated lesions, and can be repaired without mortality and with good functional results.