Unusual Manifestation of an Extracranial Carotid Artery Aneurysm: Airway Compression

Significance Statement

Aneurysms of the extracranial carotid artery are rare and mostly located in the common carotid artery bifurcation and proximal part of the internal carotid artery. They may present with many uncommon clinical symptoms according to where located. We reported here an unusual manifestation of the aneurysm of the extracranial internal carotid artery.

Introduction

Aneurysms of the carotid artery are rare and account for less than 1% of all arterial aneurysms. There are many known causes of extracranial carotid artery aneurysms (ECAA), such as atherosclerosis, infection, fibromuscular dysplasia, and trauma. Atherosclerosis is the most common cause of all aneurysms of the carotid artery.^1,2 It represents 46–70% of all etiological factors. ¹

Although any part of the carotid artery can be affected, the prevalent areas are the bifurcation of the common carotid artery and the proximal part of the internal carotid artery. Small aneurysms may be asymptomatic. However, most ECAAs are recognized as a pulsatile expandable mass in the neck. Local symptoms such as swelling and pain are common, but as the size of the aneurysm increases, uncommon manifestations may appear. Due to compression to adjacent nerves, the patient can complain of dysphagia, auricular pain, or hoarseness. Despite all this, the most important neurological symptoms occur secondary to embolic events on the wall of the aneurysms. In this case, we reported oropharyngeal airway compression as a rare manifestation of an internal carotid artery aneurysm of the extracranial area.

Case Presentation

A 52-year-old woman presented difficulty swallowing and shortness of breath that increased with time. The patient denied any neurologic symptoms. Additionally, the patient did not describe significant weight loss in the previous period. In her medical history, it was learned using antihyperlipidemic and antihypertensive agents. She had no history of trauma or surgical operation.

The patient's blood pressure, blood chemistry, and hematology values were normal at admission. On physical examination, there was a pulsatile mass on the right side of the neck. There was no other remarkable finding on examination.

First, a Doppler ultrasound was scheduled on the patient. Ultrasound examination showed a partially thrombosed mass related to the internal carotid artery on the right side of the neck (not shown here). Further imaging was performed with contrast enhancement computed tomography (CT) angiography evaluation. CT imaging defined a mass with contrast enhancement on the right side of the neck. A careful evaluation confirmed that the lesion was an aneurysm originating in the internal carotid artery (Figure 1A). The dimensions of the aneurysm were measured as 3 × 4 × 5 centimeters. Additionally, partial thromboses in the aneurysm (Figure 1B). The air column narrowed at the oropharyngeal level due to the mass effect of the aneurysm (Figure 1C).

Figure 1.

(A) Coronal volume rendering reformat 3D CT demonstrates a giant aneurysm (star) originating from the right internal carotid artery. (ECA, external carotid artery; ICA, internal carotid artery) (B) Coronal CT scan reveals partially thrombosed aneurysm (star). (C) Air specific 3D reformat anteroposterior CT image shows compression (arrow heads) of the air column secondary to the giant aneurysm.

Conclusion

Extracranial internal carotid artery aneurysms are rare and account for only 0.1% to 2% of all carotid artery-related operations. ³ ECAAs are three times more common in men than in women. Age of occurrence is with a mean age of 53–56 years but a wide range (18–70 years). ⁴ Atherosclerosis is the most common cause of ECAA. In addition to atherosclerosis, ECAAs may be associated with fibromuscular dysplasia, infections, and trauma. Extracranial internal carotid artery aneurysms are found primarily in the bifurcation of the main carotid artery and the proximal part of the internal carotid artery.

The most common presentation of ECAA is a mass on the neck. However, symptoms vary depending on the location and size. Regional pain usually occurs. Furthermore, if the aneurysms compress into the adjacent nerves, many neurologic symptoms can occur. Dysphagia can occur secondary to compression of the nerve supply to the pharynx, or auricular pain can occur secondary to compression of the glossopharyngeal nerve.

The most prominent neurological disorders develop secondary to embolic events originating from thrombus in the aneurysm. To prevent these neurological disorders such as stroke and transient ischemic attack, conservative treatment is necessary that includes anticoagulation and antiplatelet aggregation. However, active surgical intervention is the main method of treatment.

Doppler ultrasound is the first choice imaging modality for diagnosing ECAA. However, if the location of the lesion is high, ultrasound may not be sufficient. Additionally, ultrasound sensitivity decreases in patients with a short neck and in an examination focused only on the evaluation of stenosis.

CT with three-dimensional reconstruction provides much information about the location, size, and structure of the aneurysm. In addition to these, it can be a guide for surgical treatment.

Our case was related to an uncommon manifestation of an internal carotid artery extracranial aneurysm. Carotid artery aneurysms should be considered in patients with complaints of palpable swelling in the neck or shortness of breath. Thus, a life-threatening cause can be avoided.

Supplemental Material

Supplemental Material - Unusual Manifestation of an Extracranial Carotid Artery Aneurysm; Airway Compression

Supplemental Material for Unusual Manifestation of an Extracranial Carotid Artery Aneurysm; Airway Compression by Fahri Aydin, Hayri Ogul, and Mecit Kantarci in Ear, Nose & Throat Journal