Use of flow diverter stent for treatment of a cervical carotid artery dissection and pseudoaneurysm causing Horner's syndrome.

A 28-year-old man in 2004 was identified with a spontaneous pseudoaneurysm and distal left cervical internal carotid artery (ICA) dissection. The patient was followed conservatively for 12 years with cross-sectional imaging. The patient was initially diagnosed with an acute left ICA dissection, with significant luminal narrowing. Follow-up imaging revealed the dissection was not completely healed, and a small pseudoaneurysm, about 4 mm in size, was formed in the distal left cervical ICA. During the 12-year observation period, the patient's pseudoaneurysm expanded from 4.0 mm to 9.0 mm, and the patient presented with ptosis, anisocoria and myosis. Flow diverter embolisation resulted in a radiographic cure of the pseudoaneurysm and resolution of Horner's syndrome.