Background The formation of de novo pseudoaneurysms after stent implantation has not been well characterized after stenting of intracranial vessels. Its clinical significance is unknown, resulting in a difficult decision making process with regard to its treatment.

Methods The database of patients treated at the Baptist Cardiac and Vascular Institute, Miami, Florida, was reviewed. All patients with symptomatic intracranial atherosclerotic disease (ICAD) who underwent angioplasty and stenting with the Gateway-Wingspan system under the Food and Drug Administration Humanitarian Device Exemption protocol and had subsequent follow-up imaging demonstrating de novo pseudoaneurysm formation after stent implantation were included.

Results 21 patients with symptomatic ICAD who underwent angioplasty and stenting had follow-up angiography performed. Of these, we identified three patients (14%) who had de novo pseudoaneurysm formation in the follow-up angiography. All three patients were men in their sixties. All of our patients were asymptomatic and the lesions were found on routine follow-up angiography. No intervention was performed. One patient underwent intravascular ultrasound for better characterization of the lesion. Two lesions had either resolved or decreased in size on follow-up angiography. The other lesion remained stable.

Conclusions Post stenting pseudoaneurysm formation is a possible complication after intracranial stenting with unknown clinical significance. Our small series suggest that these cases may be managed conservatively.