In-Stent Stenosis as a Delayed Complication of Neuroform Stent-Supported Coil Embolization of an Incidental Carotid Terminus Aneurysm

A, Unsubtracted image depicting a Neuroform stent positioned across the neck of the coiled right ICA terminis aneurysm with the proximal and distal ends of stent indicated by four radiopaque stent markers (arrows). B, Subtracted images from a right ICA angiogram demonstrating near-complete occlusion of the aneurysm with a small focus of residual filling along the medial aspect of the aneurysm neck. The radiopaque proximal and distal stent markers are faintly visualized as foci of subtraction artifact (arrows), terminating within the supraclinoid ICA and M1 segment of the MCA, respectively. The stent is widely patent and the stented segments of the parent vessels appear completely intact. Specifically, there is no evidence of dissection or vasospasm.

Right ICA cerebral angiogram demonstrating high-grade in-stent stenosis within the M1 segment of the right MCA, just distal to the carotid terminis (white arrow). There is also narrowing of the supraclinoid ICA, just adjacent to the proximal stent markers. The proximal and distal stent markers (black arrows) are not well visualized on this subtracted image.

Postangioplasty control angiography demonstrating mild residual in-stent stenosis involving the M1 segment of the right MCA (arrow). The distal ICA stenosis is unchanged.