Introduction/purpose Dissecting pseudoaneurysms (DPAs) are rare but challenging entities, with significant reported mortality and morbidity. However, we believe the cervical or intracranial but extradural dissecting pseudoaneurysms are a different entity.

Methods Institutional Review Board approval was obtained for this study. Retrospective review of our database containing 943 patients with aneurysm treatment between 2001–2015 was reviewed. Inclusion Criteria: All patients with spontaneous or traumatic cervical or intracranial extradural dissecting pseudoaneurysms (DPAs). Exclusion Criteria: 1) Intradural dissecting pseudoaneurysms (DPAs); 2) Isolated intracranial dissection with no associated pseudoaneurysm; 3) Infective (Mycotic) pseudoaneurysms; 4) Pseudoaneurysms related to oropharyngeal tumoral infiltration.

Patient demographics, clinical presentation, aneurysm characteristics, treatment details, complications and outcomes based on follow-up imaging and clinical information were collected from the database. Procedure modalities and treatment outcome were collected from patient chart. Follow-up imaging used MRA or DSA or both. Clinical outcome was evaluated at the last known clinical follow-up based on modified Rankin Score (mRS).

Results A total of 14 patients (M:F = 8:6) with 14 DPAs constituted our study population. The mean age was 55.9 ± 17.2 years (range: 18–81 years). Six patients (43%) had traumatic DPAs (1: Gunshot injury and 5: Motor vehicle accident), 5 patients (36%) had iatrogenic injury (2: Cervical spine internal fixation; 2: Pituitary adenoma resection and 1: Planum sphenoidale meningioma resection) and 3 patients (21%) had spontaneous dissection. Seven patients (50%) had ischemic presentation from distal emboli or focal neurologic deficit. None had hemorrhagic presentation.

DPAs were equally distributed in the anterior and posterior circulation. Mean DPA diameter was 4.7 ± 3.2 mm (range: 2.0–15 mm).

Parent vessel occlusion (PVO) was the most commonly used treatment modality (79%; n = 11) with variable use of coils (n = 7), Amplatzer occlusion device (n = 1) or both (n = 3). Three patients had vessel preservation approach using coils (n = 1), stenting (n = 1) and the combination of both (n = 1). There were no technical or procedural complications. The median hospital length of stay was 7 days.

The median short-term angiographic follow-up was 42 ± 22 days (2–79 days). The median long-term angiographic follow-up was 16.5 ± 16.7 months (0–65 months). Two patients (14%) were lost for long-term follow-up. All the patients had complete obliteration of the DPAs; parent vessel remained obliterated in patients with parent vessel occlusion at both short and long-term follow-up. No patients required a repeat treatment.

The mean last known clinical follow-up was 23.3 ± 25.1 months. Two patients (14%) were lost to clinical follow-up. Nine patients (75%) had mRS score of ≤ 1 and 3 patients (25%) had mRS of 2.

Conclusions Parent vessel occlusion (PVO) is a feasible, safe and reliable treatment option for cervical or intracranial extradural dissecting pseudoaneurysms with an excellent clinical outcome and no evidence of recanalization at long-term follow-up.

Disclosures S. Boddu: None. D. Kimball: None. M. Crimmins: None. A. Banihashemi: None. J. Knopman: None. A. Patsalides: None. P. Gobin: None.