Circumflex Coronary Artery Originating from the Pulmonary Artery: A Rare Clinical Entity

Pediatric coronary anomalies are relatively rare. Anomalous left coronary artery from the pulmonary artery (ALCAPA) or anomalous right coronary artery from the pulmonary artery (ARCAPA) are known anomalies. Among coronary artery anomalies, the Left Circumflex artery (LCx) is the most common abnormality, with an incidence of approximately 20 percent, and it typically originates from the Right Coronary Artery (RCA) ^[1]. Left circumflex artery arising from the pulmonary artery (LCx) is exceedingly rare ^[2,3]. In adult patients, ALCAPA has been reported to cause sudden cardiac arrest in case reports ^[4]. Therefore, surgical treatment of coronary anomalies should be immediately considered.

A 30-year-old male patient was admitted to our clinic with complaints of palpitations and chest pain. Upon physical examination, the patient's heart exhibited hyperdynamic activity. The patient had previously undergone surgery 14 years ago for subaortic stenosis and was known to have a bicuspid aortic valve. A strong suspicion of an aortic pathology prompted us to conduct an echocardiogram, which revealed significant bicuspid aortic valve regurgitation and an ascending aorta measuring 4.7 cm. CT angiography confirmed that the LCx originated from the right pulmonary artery (Figure 1) and identified a root aneurysm in the ascending aorta, along with thickening of the aortic leaflets. As a result, a Bentall procedure and a CX anastomosis were planned. As a result, a Bentall procedure and a CX anastomosis were planned. As the surgical technique, the aortic valve was resected. Both coronary arteries were prepared as button. The Cx coronary artery arising in the right pulmonary artery was divided from the pulmonary artery. The end was clipped. The No: 27 mechanical valve was sutured into the No: 30 dacron graft. The conduit aorta with valve was anastomosed with individually pledgeted sutures. Left coronary and right coronary arteries were anastomosed to the conduit with 5/0 prolene.  Distal aorta anostomosis was performed with prolene continuous suture.

We present an illustrative case in Figure 1, showing the left circumflex artery arising from the right pulmonary artery in the preoperative CT angiogram of our patient. There are well-established aortic collateral circulations supplying the left circumflex artery and its branches, with blood flow directed from the left circumflex artery to the pulmonary artery. Additionally, the presence of a bicuspid aortic valve and aortic valve thickening is evident.