In-stent stenosis as a delayed complication of neuroform stent-supported coil embolization of an incidental carotid terminus aneurysm

Abstract

The Neuroform stent is the first microcatheter-delivered stent designed specifically for the treatment of cerebral aneurysms. The stent functions primarily to provide durable parent vessel protection during the embolization of broad-necked cerebral aneurysms. The present case report demonstrates in-stent stenosis occurring as a delayed complication of Neuroform stent-supported coil embolization of an unruptured cerebral aneurysm.

Fig 1.

Right ICA angiogram depicting a 9-mm broad-based aneurysm arising from the right ICA terminus.

Fig 2.

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.

Fig 3.

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.

Fig 4.

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

Fig 5.

Follow-up posteroanterior (A) and lateral (B) right common carotid angiogram demonstrates a patent STA-MCA bypass (white arrow). There has been marked interval progression of the stenosis within the proximal M1 segment of the right MCA (black arrow), which is now preocclusive. Most flow to the right MCA circulation is supplied from the bypass, minimal anterograde flow through the highly stenotic M1 segment was substantially delayed.