Long-term clinical and mid-term radiographic follow-up of pure arterial malformations.

BACKGROUND Pure arterial malformations (PAMs) are rare vascular lesions characterized by dilated, tortuous arterial loops without venous shunting. The natural history of PAMs remains unclear. We report the mid-term radiological and longer-term clinical outcomes of the largest series of patients with PAM. METHODS Retrospective review at a tertiary academic referral center for patients with a PAM. Follow-up clinical and radiological data were collected and analyzed for clinical symptoms and radiographic changes. RESULTS Twenty-five patients met the inclusion criteria. The mean age at presentation was 30.9 ± 14 years. Nineteen (76%) patients were female, and six (23.1%) were male. Eleven (44%) patients had ≥1 symptom at presentation, of which only 3 (12%) could be linked to PAM. The most common symptom was headache (n=8). PAMs involved a single vessel in 16 (64%) cases and ≥2 vessels in 9 cases (36%). Fifteen (60%) lesions were isolated to the anterior circulation compared to 6 (24%) in the posterior circulation. The most frequently involved vessel was the supraclinoid internal cerebral artery (36%). An associated saccular aneurysm was present in 32% of patients. Ten lesions were partially calcified. The mean radiographic and clinical follow-up was 21.9 ± 26.5 months and 44.6 ± 34.8 months, respectively. None of the patients developed new symptoms related to their lesion or radiographic progression over the duration of follow-up. CONCLUSIONS PAMs are found most frequently in young, asymptomatic females. PAMs have a benign natural history and are best managed conservatively with serial imaging.