Winning Abstracts from the 2010 Medical Student Abstract Competition: An Aberrant Right Subclavian Artery And Duct Of Kommerell Aneurysm Complicated By Dissection
Author: Vanessa Gray, MS IV
Texas A&M HSC College of Medicine/Scott and White Hospital, Temple, TX
Introduction: Chest pain is a common chief complaint with nearly six million visits to emergency departments each year. There are numerous causes of chest pain, with many having potentially deadly consequences. A duct of Kommerell aneurysm, a rare complication of an aberrant right subclavian artery (ARSA), is one that can be potentially fatal if not diagnosed promptly and accurately; however, with its non-specific symptoms of dysphagia, cough and less commonly chest pain, making the diagnosis of this congenital anomaly is both challenging and imperative.
Case Presentation: A 57-year-old man presented with a 30-45 minute history of tearing chest pain that radiated to his left jaw, neck, and interscapular region. He had no other associated symptoms, and no prior history of this type of chest pain. Physician examination revealed significantly higher systolic blood pressures in his lower extremities when compared to his upper extremities and chest tenderness that was reproducible with palpation. Initial blood work was unremarkable with negative cardiac markers, an ECG showing ventricular paced rhythm, and a chest X-ray demonstrated mediastinal widening. A CT scan confirmed an intimal flap in the descending aorta, an intramural hematoma, and an anomaly posterior to the esophagus that joined with the aortic arch. Consequently, the patient was diagnosed with an aberrant right subclavian artery, a duct of Kommerell aneurysm, and a Type B aortic dissection. He underwent emergent surgery to repair the ARSA by reanastomosis to the brachiocephalic artery, and placement of a Dacron graft to correct his dissection.
Discussion: In 1936, Dr. Kommerell was one of the first physicians to clinically diagnose an aberrant right subclavian artery and duct of Kommerell aneurysm, hence his namesake, in a patient who presented with dysphagia. The ARSA was later found to originate from the incomplete embryonic development of the right, fourth aortic arch. The incidence of an ARSA is around 1% of the total population, while occurrence of a duct of Kommerell aneurysm is only 0.5% of the total population. Common complications of an ARSA are atherosclerosis, aneurysms, dissections, and vascular stenosis. Interestingly, our patient did not present with cough or dysphagia, symptoms commonly seen with an ARSA and duct of Kommerell aneurysm secondary to compression of the posterior esophagus. Thus, this case exemplifies that while it is exceedingly rare to find an aberrant right subclavian artery, a duct of Kommerell aneurysm and a Type B dissection occurring simultaneously, it is important to use a systematic approach and have a broad differential diagnosis when working up a patient with chest pain in order to prevent potentially fatal complications.