Discussion
This case report showed a rare condition with a combination of a Kommerell diverticulum (KD) and two thoracic aortic aneurysms, which were treated by combination of open surgical repair and thoracic endovascular aortic repair (TEVAR). An aberrant subclavian artery (ASA) results from a developmental error in the fourth aortic arch, and persistence of a left-sided or right-sided aortic arch results in a right or left ASA, respectively [1]. The prevalence of a right ASA is 0.5% to 2% [2]. In general patients with a right ASA are asymptomatic. However, some patients present with dyspnea, dysphagia stridor, wheezing, coughing, choking spells, recurrent pneumonia, obstructive emphysema, and chest pain, because the right ASA passes behind the esophagus (80%), between the esophagus and the trachea (15%), or in front of the trachea (5%) [3]. A dilation and aneurysm at the origin of the ASA is known as Kommerell diverticulum (KD) and carries a high risk of rupture or dissection. Although there is no established management guideline because of its rarity, surgical intervention is indicated in patients with symptoms or an aneurysm to prevent a rupture [1].
Surgical, endovascular, or hybrid procedures have been described to treat an ASA and KD. An endovascular approach is less invasive than open surgery and has recently become a common procedure. However, in our case, an endovascular repair was not suitable because of the short landing zone and enlargement of the ascending arch (diameter of 42 mm). Therefore, we decided to perform a TAR with an FET. This approach is safe and effective and allows avoidance of a left thoracotomy and resection of the distal arch, and it has the advantage of avoiding recurrent nerve injury [4-7]. A second-stage TEVAR for a residual aneurysm at the descending artery was successfully performed 3 weeks after the TAR with an FET without spinal cord ischemia. Although there was a risk of a rupture of a residual aneurysm during the interval between procedures, we believed that our staged approach reduced the incidence of spinal cord ischemia. Some reports on the treatment of a KD and ASA have been reported thus far in the literature. However, it is considered rare to find two thoracic saccular aortic aneurysms coexisting with a KD, as was discovered in this patient.