Aorto--right ventricular tunnel: a new concept in congenital cardiac malformations

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: A Case Series and Literature Review

Aorto-right ventricular tunnel (ARVT) is a rare cardiac congenital anomaly where an extracardiac channel connects the ascending aorta above the sinutubular junction to the right ventricle. This defect is caused by an abnormal development of the cushions of the aorto-pulmonary outflow tract. A case series and literature review are described. Two cases of ARVT are described. A literature review was conducted, in which 31 cases were reported. In our 2 cases, both ARVTs connected the ascending aorta above the left aortic sinus to the right ventricle (one to the right ventricular outflow tract and one to the right ventricular apex). Both patients underwent successful surgical correction by patch closure of both tunnel orifices, with uneventful postoperative course. Of the 31 ARVT cases described in our review, only 10 patients (32.3%) had an anatomy similar to the 2 cases described. Coronary artery anomalies can be associated, as reported in our 2 patients and in 16 cases (51.6%) in the review. Surgical correction can be achieved by direct closure or, more often, by patch closure of one or both tunnel orifices, depending mostly on coronary anatomy. Two cases of transcatheter device closure were described in literature, in favorable anatomy cases. Careful attention is required during repair to avoid coronary lesions, due to the high incidence of comorbid coronary anomalies.

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.

Prenatal Diagnosis and Neonatal Surgical Management of a Giant Proximal Right Coronary Artery to Right Ventricular Fistula

We report a case of prenatal diagnosis and early neonatal surgical repair of a large proximal right coronary artery to right ventricular fistula. The surgical findings and technical details of the reparative operation are discussed in the context of the differential diagnosis, which, in addition to coronary-cameral fistula, also includes aortoventricular tunnel and ruptured sinus of Valsalva aneurysm. Timely and appropriate diagnosis and surgical management resulted in preserved patency of the right coronary artery and restoration of normal right ventricular function.

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-right ventricular tunnel

A 2-year-old child with aortico-right ventricular tunnel is reported for its rarity. The right coronary artery originated from the distal end of the tunnel. The frequent occurrence of coronary artery origin abnormality with this anomaly is highlighted.

Aortico-right ventricular tunnel

A successful operation on an infant with a tunnel through which the aorta communicated with the right ventricle is reported. The diagnosis was suspected preoperatively on the basis of two-dimensional Doppler color echocardiography and confirmed by cardiac catheterization. The aortico-right ventricular tunnel originated independently from the left coronary ostium and above the sinus of Valsalva. Patch closure from inside the tunnel under deep hypothermia was successfully performed. Follow-up is satisfactory 5 years later.

Repair of aortico-right ventricular tunnel

Aortico-right ventricular tunnel was successfully corrected in a 15-month-old child. Both the aortic and right ventricular openings were closed with pledgeted sutures. The coronary artery anatomy was normal. At 12-month follow-up the patient is in excellent clinical condition. Before surgical intervention for aortico-right ventricular tunnel is undertaken, every effort should be made to diagnose the coronary artery anatomy, because failure to do so in the case of aberrant origin of a coronary artery may prevent successful surgical correction.

Surgical repair of aorto-right ventricular tunnel in an infant

A rare case of aorta to right ventricle tunnel with associated pulmonary stenosis was corrected on cardiopulmonary bypass in a 3-month-old infant. Both the aortic and ventricular openings were closed with a patch. Although the repair was successful and the child was discharged from the hospital, septicemia developed and she died later. Early repair of this defect is recommended.

Surgical repair of aortico-left ventricular tunnel in a 7-day-old child

A 7-day-old girl was successfully operated on for aortico--left ventricular tunnel. She seems to have been the youngest patient with successful repair of the malformation. The case was the second of its type operated on at the Karolinska Hospital. Severe congestive heart failure is usually an early occurrence in aortico--left ventricular tunnel. The high mortality rate without operation illustrates the importance of early diagnosis and surgery. A patch closure technique is recommended as permitting optimum function of the aortic valve.