Angiographic findings of in-stent intimal hyperplasia after stent-assisted coil embolization: are they permanent findings?

Abstract

OBJECT Stent-assisted coil embolization for the treatment of intracranial aneurysms has been used widely. This study aimed to investigate the effect of stent implantation in the nonatherosclerotic parent artery with cerebral aneurysms. The authors evaluated luminal changes and the related factors following stent-assisted coil embolization. METHODS This study included 97 patients harboring a total of 99 unruptured aneurysms of the distal internal carotid artery (ICA) who underwent single-stent implantation and more than 1 session of conventional angiography during follow-up (midterm follow-up only, n = 70; midterm and long-term follow-up, n = 29) between January 2009 and April 2014. The luminal narrowing point was measured using a local thickness map (ImageJ plug-in). RESULTS Stent-assisted coil embolization caused dynamic luminal narrowing of approximately 82% of the parent artery diameter on average after 8 months, which was reversed to 91% after 25 months. In addition, luminal narrowing greater than 40% was noticed in 2 (7%) of the 29 patients who experienced spontaneous reversion without additional management during follow-up. Most luminal narrowing changes seen were diffuse. CONCLUSIONS Luminal narrowing after aneurysm stent-assisted coil embolization is a dynamic process and appears to be a spontaneously reversible event. Routine management of luminal narrowing may not cause adverse events that require additional treatment.