Extracranial Internal Carotid and Vertebral Dissecting Pseudoaneurysms: Clinical Features and Long‐Term Outcomes

BACKGROUND The formation of dissecting pseudoaneurysms (dPSAs) is a common sequela of cervical artery dissection, which has been suggested to increase thrombotic risk in previous studies. This study reported clinical features and long‐term outcomes of cervical internal carotid (cICA) and vertebral artery (cVA) dPSAs. METHODS We performed a retrospective chart review over a 10‐year period (January 2012–December 2021). Baseline demographics and clinical characteristics, medical and endovascular treatments, and long‐term outcomes were reported for cICA and cVA dPSA groups separately. Nonparametric tests were used to compare group differences. RESULTS In our cohort, 120 (12%) of 999 cervical artery dissection patients had dPSA, with 85% occurring in the cICA and 15% in the cVA. Most dPSAs occurred spontaneously or in association with minor trauma. Compared with cICA dPSA, patients with cVA dPSA were younger (median age [range]=34.5 [24–70] versus 52 [30–77]; P <0.01), had a smaller dPSA size (median size [range]=4.5 mm [2–17] versus 8 mm [1.2–32]; P <0.01), and were more likely to reduce in size at follow‐up (median size change [range]=−2.8 mm [−17;0] versus 0 [−24;10.8]). Antithrombotic therapy was predominately aspirin monotherapy. No patients with cVA dPSA experienced recurrent strokes and only 3% of patients with cICA dPSA developed new/recurrent stroke in the territory of dPSA while on an antithrombotic regimen requiring endovascular intervention, and none of the dPSAs ruptured. A total of 98% of the patients had an excellent outcome (modified Rankin scale 0–2 at final follow‐up). CONCLUSION Most cICA and cVA dPSAs have a benign prognosis with medical therapy alone. Further prospective randomized clinical trials are needed to provide high quality evidence on the necessity of additional endovascular therapy at diagnosis in addition to medical therapy alone.