Aortopulmonary window is a rare lesion that accounts for 0.1–0.2% of all congenital cardiac defects. It might be associated with complex cardiac malformations. Reference Alakhfash, Tagelden, Almesned and Alqwaiee1 As reported in literature, the association of aortopulmonary window and anomalous origin of a coronary artery is a rare condition, Reference Léobon, Bret and Roussin2 described in only 5–10% of cases. Literature also emphasised how pre-operative diagnosis of coronary anomaly might be challenging. Most of the reported diagnosis was made either intra-operatively or post-mortem. Reference Talwar, Agarwal, S. and Choudhary3 Identification of coronary artery anomalies before surgery is crucial as some of these anomalies significantly contribute to higher surgical morbidity and mortality. An early detection can influence the management strategies and may require modifications of the surgical techniques. Reference Singh, Loona, Suryavanshi, Sahoo and Mahant4
Case report
A term baby (2.9 kg) was born following an uncomplicated vaginal delivery, from a mother on insulin therapy for gestational diabetes. Prenatal ultrasound showed normal fetal biometry without fetal abnormalities. Apgar score was 9 at the first and fifth minute. On the second day of life, a systolic murmur required a cardiology consultation. Clinical evaluation showed good clinical status, normal peripheral pulses, and normal pre- and post-ductal oxygen saturation. The echocardiography performed by an adult cardiologist showed moderate pulmonary hypertension and a patent ductus arteriosus with evidence of an aortic isthmus anterior shelf. Patient was discharged at home with cardiology reevaluation after 1 week. At 1 week of age, the clinical status worsened: poor weight gain, tachycardia, and tachypnoea. The electrocardiogram presented right axis deviation with a specific ventricular repolarisation abnormalities. The echocardiography showed an aortopulmonary window: a large communication between the pulmonary trunk and the ascending aorta with low-velocity left to right shunt. The exam was also significant for normal biventricular size and function, a holo-systolic reverse flow in the descending aorta, dysplastic mitral valve with moderate regurgitation, unobstructed outflow tracts, and ascending aorta ectasia. Right coronary artery origin and course were well visualised. Although it was not possible to demonstrate the left coronary artery ostium, regular anterograde flow in the left anterior descending artery was recorded. The infant was immediately transferred to the referral cardiac surgery centre. New echocardiogram studies at the referral Hospital confirmed the initial diagnosis with normal coronary artery anatomy and origins. On day 15 of age, the patient underwent surgical correction through median sternotomy, using cardiopulmonary bypass in moderate hypothermia (28°C). Trans-aortic approach was selected to repair the defect that was closed using bovine pericardial patch. Detailed inspection of coronary arteries anatomy was not undertaken, since pre-op echo studies showed normal coronary artery pattern and blood flows. Weaning from cardiopulmonary bypass failed and very high left atrium pressure was found. Intra-operative echocardiogram showed significant left ventricular dysfunction, right coronary artery was well visualised, while left coronary artery ostium was not detected. It was then decided to re-clamp the aorta to explore the coronary anatomy, after taking down the pericardial patch, the left coronary artery ostium was found at the floor of the proximal right pulmonary artery near the orifice of the window. Then, a new pericardial patch was fashioned to baffle the left coronary ostium on the aortic side and close the window. The second attempt of weaning from cardiopulmonary bypass failed and a central Extra Corporeal Membrane Oxygenation assistance was applied as a bridge to myocardial recovery. The Extra Corporeal Membrane Oxygenation was weaned on post-operative day eight, and sternal closure was performed on post-operative day 12. Post-operative echocardiography studies showed satisfactory global systolic function, mild left ventricular dysfunction due to mild dyskinesia of the mid-basal septal wall, mild mitral valve, and mild aortic valve regurgitation. No residual shunt was detected around the patch, while moderate stenosis at the origin of the right pulmonary artery was identified without significant flow gradient. The patient was discharged at home 2 months after the surgery with anti-heart failure medications, in good general condition, good oral intake, and satisfactory weight gain. Six months after discharge, an Angio CT study show mild right pulmonary artery stenosis, normal main pulmonary artery, and moderate hypoplasia of the proximal ascending aorta without signs of stenosis.
Discussion
Aortopulmonary window results from the failure of fusion of the two opposing conotruncal ridges that separate the truncus arteriosus into the aorta and pulmonary artery. Aortopulmonary window may be classified into three types: type I (proximal), in which there is a defect between the proximal ascending aorta and the main pulmonary artery; type II (distal), in which the defect is between the proximal right pulmonary artery and the aorta, and type III in which the defect is a combination of types I and II defects. The presentation of patients with aorto-pulmonary window is similar to that of other patients with left to right shunts, such as patent ductus arteriosus or ventricular septal defect. Reference Alakhfash, Tagelden, Almesned and Alqwaiee1,Reference Singh, Loona, Suryavanshi, Sahoo and Mahant4,Reference Barnes, Mitchell and Tweddell5 Generally, the communication is large and during the first weeks of life, when pulmonary vascular resistance drops and the pulmonary blood flow increases, patients present signs of congestive heart failure: tachypnoea, diaphoresis, poor feeding, and inadequate weight gain. Aortopulmonary window can occur in isolation or may be associated with complex cardiac malformations like interrupted aortic arch, ventricular septal defect, tetralogy of Fallot, or transposition of the great arteries. Reference Alakhfash, Tagelden, Almesned and Alqwaiee1,Reference Barnes, Mitchell and Tweddell5 The association between aortopulmonary window and anomalous origin of the left coronary artery (ALCAPA) is extremely rare, also the anomalous origin of the right coronary artery from the pulmonary artery is rare, even if it has been reported more frequently in literature. Reference Talwar, Agarwal, S. and Choudhary3,Reference Alhadlaq, Dhillon, Hancock-Friesen and Hussain6 Our patient presented with early manifestation of congestive heart failure without clinical or echocardiographic signs suggestive for the presence of ALCAPA such as myocardial ischaemia. Aortopulmonary window keeps pulmonary artery pressure high, even when the pulmonary resistance drops. In this condition, the perfusion pressure in the anomalous coronary artery is maintained and myocardial ischaemia is less likely to develop. Reference Alakhfash, Tagelden, Almesned and Alqwaiee1 After surgical closure of the aortopulmonary window, the combined low pressure in pulmonary circulation and low oxygen saturation of the perfused blood through the anomalous coronary artery lead to myocardial ischaemia. Reference Léobon, Bret and Roussin2,Reference Talwar, Agarwal, S. and Choudhary3 If the ultrasound diagnosis of aortopulmonary window is not always straightforward, the diagnosis of anomalous origin of coronary arteries, especially anomalous origin of the left coronary artery from the pulmonary artery, in association with aortopulmonary window it is very complicated and remains a challenge for the clinician. The rarity of these lesions, the absence of indirect signs of ALCAPA, such as ventricular dysfunction or hyperechogenic papillary muscles, the heterogeneity of the anomalous coronary artery anatomy, and the turbulent flow across the aortopulmonary window make pre-operative diagnosis extremely demanding. Reference Singh, Loona, Suryavanshi, Sahoo and Mahant4,Reference Alhadlaq, Dhillon, Hancock-Friesen and Hussain6
Conclusions
This report highlights one more time the importance of a very careful assessment of the coronary arteries in patients with aortopulmonary window. Currently, echocardiography is the main and the most important imaging study performed before surgical repair in newborns and small infants, but in some cases it fails to identify the presence of coronary artery anomalies. In presence of an aortopulmonary window, some authors report that extensive collateral flow within the myocardium may represent a clue to detect an abnormal coronary origin. In our case, this indirect sign was not found.
Even if echocardiography evaluation does not suggest the presence of anomalous origin of the coronary artery, an intraoperative investigation must be done. Early recognition of coronary artery anomalous origin allows to modify surgical plan and to prevent myocardial ischaemia and cardiac dysfunction. Should we perform more detailed imaging studies during pre-surgical diagnostic evaluations? And if so, should we use cardiac catheterisation with angiography or the computed tomography?. Reference Doty, Richardson, Falkovsky, Gordonova and Burakovsky7
Acknowledgements
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Financial support
This research received no special grant from any funding agency, commercial, or not-for-profit sectors.
Conflicts of interest
None.
Ethical standards
The authors assert that all the procedures contributing to this work comply with the ethical standards.
