Right-sided aortic arch with Kommerell's diverticulum: a case report of a rare cause of type B dissection

Abstract

Background: A right-sided aortic arch (RAArch) is present in approximately 0.1% of the population. A Kommerell's diverticulum (KD), a remnant of the dorsal aortic arch usually refers to an aneurysmal aortic enlargement at the origin of an aberrant left subclavian artery (ALSA) and is associated with an increased risk of aortic dissection.

Case summary: A 59-year-old female smoker with a history of hypertension and hypercholesterolaemia presented with a 24-hour history of sudden-onset and severe stabbing chest pain radiating to the interscapular region. Physical examination was normal except for bilateral basal crepitations. Computed tomography angiography (CTA) showed a type B aortic dissection in a RAArch with an ALSA arising from KD with a peri-aortic haematoma and haemothorax without any active contrast extravasation. After medical stabilization, a semi-urgent hybrid repair was performed with a right carotid-subclavian bypass, thoracic endovascular aortic repair (TEVAR), a plug in the left subclavian artery, and left carotid-subclavian bypass due to severe ischaemia of the left arm. The postoperative CTA showed patent bypasses, aortic remodelling, and a minimal type IIa endoleak at the level of the ALSA.

Discussion: In patients with a type B dissection and KD, hybrid repair including TEVAR is feasible after careful pre-operative assessment of the patient's unique anatomy and may reduce post-surgical morbidity and mortality compared to open surgery. Prophylactic repair may be considered in patients with an asymptomatic RAArch and KD.

Keywords: Acute aortic syndrome; Aortic dissection; Case report; Congenital aortic anomaly; Kommerell's diverticulum; Right-sided aortic arch.

Figure 1

Three-dimensional virtual rendering technique reconstructions of the pre-operative computed tomography angiography in an anteroposterior (A) and a left lateral (B) view, left lung apex is cut away. Solid arrow: Kommerell diverticulum; dotted arrow: false lumen of the dissection. ALSA, aberrant left subclavian artery ascending from Kommerell’s diverticulum; RSA, right subclavian artery; RCCA, right common carotid artery; LCCA, left common carotid artery. Images: D. Devos, MD, PhD, cardiovascular radiologist.

Figure 2

Conventional slices of the pre-operative computed tomography angiography. Axial slice showing the aberrant left subclavian artery ascending from Kommerell’s diverticulum and the start of the aortic dissection, the peri-aortic hematoma and the right-sided haemothorax (A). Coronal slice showing the distal part of the aortic dissection in the descending aorta and the peri-aortic hematoma (B). AA, ascending aorta; ALSA, aberrant left subclavian artery ascending from Kommerell’s diverticulum; FL, false lumen; LCCA, left common carotid artery.

Figure 3

Illustration of the vascular anatomy after hybrid repair with an endovascular stent-graft covering the entire descending thoracic aorta including the ostia of both subclavian arteries (A), a bilateral carotid-subclavian bypass (B), and an Amplatzer plug in the aberrant left subclavian artery just distal of Kommerell’s diverticulum (C). Copyright Donna Wouters, MD, general surgery resident.

Figure 4

Three-dimensional virtual rendering technique reconstructions of the follow-up computed tomography angiography in an anteroposterior (A) and a left lateral (B) view, left lung apex is cut away. Solid arrow: left carotid-subclavian bypass; dotted arrow: right carotid-subclavian bypass. ALSA: aberrant left subclavian; LCCA: left common carotid artery; RSA, right subclavian artery; RCCA, right common carotid artery. Images: D. Devos, MD, PhD, cardiovascular radiologist.