Images in Vascular Medicine: Vascular complications in a young patient with vascular Ehlers–Danlos syndrome

A 23-year-old man was referred to the vascular medicine clinic after experiencing a spontaneous splenic artery aneurysm rupture, requiring coiling, a few months previously. He had no other medical history. Initial imaging included a carotid ultrasound which showed mild irregularities of the carotid artery walls, particularly seen on a power Doppler image (Panel A). Computed tomography angiography (CTA) of the head and neck revealed aneurysmal dilatation and a pseudoaneurysm (~1.1 cm) of the distal left cervical internal carotid artery (ICA) (Panels B-1 and B-2, arrows), short-segment dissection and pseudoaneurysm of the left vertebral artery (Panels C-1 and C-3, arrows), and small-segment dissection of the distal right ICA (Panel C-2, arrow). Faint beading of the distal left ICA (Panel B-3, arrow) was also seen. Owing to the patient’s remarkable CTA findings in the setting of his young age and lack of significant prior medical history other than spontaneous arterial rupture, the patient was referred for genetic testing to evaluate for connective tissue disorder. The mild arterial wall irregularities seen on carotid ultrasound and the faint beading of the distal left ICA seen on CTA, along with the presence of aneurysms and dissections, meant fibromuscular dysplasia (FMD) was considered; however, connective tissue disease was thought to be much more likely. Additionally, the International Consensus on the diagnosis and management of FMD stipulates that multifocal beading must be seen in an artery free of dissection to confirm the diagnosis of FMD. This is because healing dissection can mimic vessel wall irregularity seen in multifocal FMD. ¹ The genetics test revealed a pathogenic variant of COL3A1 (p.Gly906Asp), yielding a diagnosis of vascular Ehlers–Danlos syndrome (vEDS). The patient was asked to monitor his blood pressure closely, avoid activities such as heavy weightlifting and maneuvers that could increase chances of arterial rupture, and attend a follow-up in our clinic in 6 months.

Panel A. Panel B. Panel C. Panel D.

Five months later, the patient presented to clinic complaining of 10-day onset of worsening headache radiating to the left eye associated with left eye blurriness and pulsatile tinnitus. On exam, he had left eye ptosis and was unable to adduct his left eye, suggesting sixth nerve palsy and ocular sympathetic dysfunction. A CT head was obtained, which showed a new focal cavernous ICA aneurysm (2.2 cm). The decision was made to admit the patient to the hospital, and the neuro-interventional radiology (IR) team was consulted. Neuro-IR performed cerebral digital subtraction angiography, which demonstrated a left direct Barrow Type A carotid-cavernous fistula (CCF) (Panel D-1, arrow). After transvenous coiling of the fistula (Panel D-2, arrow), restoration of the left anterior circulation was achieved (Panel D-3).

vEDS is a rare autosomal dominant condition (estimated to occur in 1:50,000–200,000 individuals) resulting from mutations in COL3A1, the gene encoding the alpha-1 chain of type III collagen; type III collagen is an important component of the extracellular matrix of both vasculature and hollow organs. This causes the vasculature and tissue of patients with vEDS to be much more fragile and susceptible to dissection and rupture. ² In addition to spontaneous arterial dissection/rupture and visceral organ rupture, fistula formation is another complication of vEDS. Barrow Type A (direct) CCF is a high-flow fistula connecting the ICA and the cavernous sinus, which could develop due to an aneurysm rupture, as in the case of our patient. ³ The acute presentation and potential devastating consequences of direct CCF warrants prompt diagnosis and endovascular intervention (which has been shown to have a high cure rate of 90–100% and low rate of complications of < 1%). ⁴