An analysis of an aberrant circumflex artery originating from the right aortic sinus and its clinical implications.

During routine cadaver dissection, a coronary vessel abnormality was discovered in a 71-year old female cadaver. The circumflex artery (CxA), normally a branch from the left coronary artery (LCA), took its origin from the root of the right coronary artery (RCA) instead. It appears to exit the right aortic sinus sharing the same coronary ostium as the RCA. The vessel veered left, taking a retroaortic course between the aorta and left ventricle towards the left side of the heart. Although the female donor’s death was due to chronic hypoxemia and respiratory failure secondary to chronic obstructive pulmonary disease, there was no medical history evidence of pathological conditions due to the variant coronary vessel. The aberrant CxA is rare due to its origin from the RCA. In addition, the normal perfusion area for the CxA appears markedly reduced in this case, possibly due to constriction as it loops posterior to the aorta. Preliminary measurement of the CxA indicated some possible sites of constriction, and overall the diameter of the vessel was small. Furthermore, the RCA and LCA perfusion areas appeared to compensate for the reduction. Surgical case reports implicate the significance of a CxA arising from the right coronary sinus. One such clinical significance for this variant would be an increased difficulty with aortic valve replacement due to the origination site of the CxA.