A Rare Case of Spontaneous Extracranial Internal Carotid Artery Aneurysms and their Management

Sir, We describe a case of a 62-year-old female patient presented to us with pulsatile swelling over the left side of the neck for 2 months. Magnetic resonance imaging (MRI) angiography of the neck vessels that revealed outpouching arising from the proximal left internal carotid artery [Figure 1a]. Four vessels Digital Subtraction Angiography (DSA) of neck vessels revealed two outpouchings arising from the left internal carotid artery few centimeters above its origin. Proximal one was about 7 mm × 8 mm in size, while distal outpouching was of 35 mm × 18 mm in size suggestive of aneurysms [Figure 1b and c]. During the procedure, we found out that there was no cross flow from left-sided internal carotid artery (ICA) circulation. The presence of connective tissue disorders like Ehlers–Danlos syndrome, Neurofibromatosis-1, and Marfan’s syndrome was also ruled out. With the consent of relatives, she underwent endovascular intervention with the use of covered stent (Fluency) 60 mm × 6 mm size stent [Figure 2 a-c]. Postprocedure check angiography confirmed the desired position of the stent. Patient was conscious, oriented to time place and person with no neuro-deficit postprocedure. At the 6-month follow-up, the patient was asymptomatic with no neck swelling.Figure 1: Magnetic resonance imaging (MRI) angiography of the neck vessels showing out pouching arising from the proximal left internal carotid artery (a). Four vessels Digital Subtraction Angiography (DSA) of neck vessels showing revealed two outp ouchings arising from the left internal carotid artery few centimeters above its origin on antero-posterior view (b) and lateral view (c)Figure 2: Fluoroscopic image showing covered stent across the aneurysms (a). Post stent deployment DSA image showing complete disappearance of the aneurysms on antero-posterior view (b) and lateral view (c)Discussion Extracranial carotid artery aneurysms (ECCA) are infrequent entity accounting for 0.8 to 1% of all aneurysms. They can be subdivided into true or false (pseudo) aneurysms.[1] True aneurysms are the localized permanent enlargement of the artery diameter, with the integrity of all vascular layers. They constitute less than 10% of ECCA. The primary causes of true aneurysms include atherosclerosis and congenital pathologies such as Marfan’s syndrome, fibromuscular dysplasia, and medial degeneration.[2] The most common presenting symptoms include neck pain followed by pulsatile cervical mass. Other symptoms include transient ischemic attack/stroke, stridor and voice, rupture cranial nerve palsy (through direct compression), or swallowing problems.[3] Digital subtraction angiography (DSA) is the gold standard investigation. However, CT angiography or MR angiography are essential to provide the extent, vessel wall imaging and intraluminal thrombus and to plan surgical strategies accordingly.[4] With the advent of recent endovascular techniques, it is becoming the first line of management for ECCA. Endovascular techniques include coiling the aneurysm with or without stents, covered stents and use of flow diverters. The covered stent is self-expanding nitinol stent covered with polytetrafluoroethylene (PTFE) graft material which is safe material for use for vessels. They exert a gentle outward force which helps them for a better wall apposition and flow diverting effect due to small pores.[5] Covered stents provide an immediate closure of the aneurysms and reconstruct the arterial wall. All the patients require dual antiplatelet therapy (DAPT) for prevention of stent thrombosis. A standard regimen includes is DAPT for 6 months with lifetime monotherapy.[6] Declaration of patient consent: The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.