Background Although intracranial stenting has been associated with in-stent stenosis, the vascular response of cerebral vessels to the deployment of the Enterprise vascular reconstruction device is poorly defined.

Objective To evaluate the change in parent vessel caliber that ensues after Enterprise stent placement.

Methods Seventy-seven patients with 88 aneurysms were treated using Enterprise stent-assisted coil embolization and underwent high-resolution three-dimensional rotational angiography followed by three-dimensional edge-detection filtering to remove windowing-dependence measurement artifact. Orthogonal diameters and cross-sectional areas (CSAs) were measured proximal and distal on either side of the leading stent edge (points A, B), trailing stent edge (points D, E), and at mid-stent (point C).

Results Enterprise stent deployment caused an instant increase in the parent artery CSA by 8.98% at D, which was followed 4–6 months later by significant in-stent stenosis (15.78% at A, 27.24% at B, 10.68% at C, 32.12% at D, and 28.28% at E) in the stented artery. This time-dependent phenomenon showed resolution which was complete by 12–24 months after treatment. This target vessel stenosis showed significant age dependence with greater response in the young. No flow-limiting stenosis requiring treatment was observed in this series.

Conclusions Use of the Enterprise stent is associated with a significant dynamic and spontaneously resolvable age-dependent in-stent stenosis. Further study is warranted on the clinical impact, if any, of this occurrence.