Right-sided Aortic Arch with Aberrant Left Subclavian Artery Arising from a Kommerell Diverticulum: A Case Report

Right-sided aortic arch with an Aberrant Left Subclavian Artery (ALSA) arising from a Kommerell diverticulum is a rare congenital anomaly of the aortic arch system. A 58-year-old male presented with progressive exertional breathlessness and intermittent dysphagia. Contrast-enhanced CT aortography with multiplanar and three-dimensional reconstructions demonstrated a right-sided aortic arch with sequential branching of the left common carotid artery, right common carotid artery, right subclavian artery, and an ALSA arising from a Kommerell diverticulum. The aberrant vessel followed a retro-oesophageal course, causing indentation of the oesophagus, explaining the patient’s dysphagia. Mild fusiform dilatation of the aortic arch was also observed without evidence of dissection or rupture. This case highlights the importance of multidetector CT angiography in the diagnosis and anatomical characterisation of rare aortic arch anomalies. Early recognition of Kommerell diverticulum is important for appropriate clinical management, surveillance, and prevention of potential vascular complications.