Optical coherence tomography of the intracranial vasculature and Wingspan stent in a patient

Abstract

A 67-year-old man with medically refractory vertebrobasilar insufficiency and short segment occlusions of the intracranial vertebral arteries was treated with angioplasty and stent placement. Fifteen hours after the procedure the patient developed symptoms of posterior fossa ischemia and repeat angiography showed thrombus formation within the stent which was treated with thrombolytic and aggressive antiplatelet therapy. Angiography revealed lysis of the clot, but concerns regarding the mechanism of the thrombotic phenomenon prompted frequency-domain optical coherence tomography (FDOCT) assessment. FDOCT provided excellent visualization of the stent and vessel wall interactions, as well as excluding residual flow-limiting stenosis, obviating the need for further intervention. The potential utility of FDOCT in the evaluation of intracranial atherosclerotic disease and additional intracranial applications are discussed.

Keywords: Atherosclerosis; Catheter; Stent; Technology; Vessel Wall.

Figure 1

Anterior-posterior (A) and lateral (B) projections from the digital subtraction angiogram (DSA) showing short segment occlusion of the right vertebral artery at the vertebrobasilar junction with only faint opacification of the basilar artery (black arrowheads). There is a lesser degree of stenosis present at the level of the posterior inferior cerebellar artery (PICA) (red arrowhead). Post-intervention DSA in the anterior-posterior (C) and lateral (D) projections showing restoration of near normal lumen and flow within the right vertebrobasilar system following angioplasty/stent placement. The lesser stenosis at the level of the PICA was treated solely with balloon angioplasty. Unsubtracted anterior-posterior magnified view (E) showing overlapping segments of the proximal (black arrows) and distal (red arrows) stents, visible by the four radiopaque markers on the proximal/distal aspects of the stents.

Figure 2

Anterior-posterior (A) digital subtraction angiography image obtained 15 h after completion of the initial procedure showing non-occlusive thrombus (red arrowheads) within the mid portions of the stent construct. Anterior-posterior radiograph (B) demonstrating the position of the frequency-domain optical coherence tomography (FDOCT) catheter over the microwire, with delineation of the imaging length of the catheter (white arrows) and the monorail segment (black arrows). Dashed circles in (B) correspond to the cross-sections from the FDOCT acquisition (C–F). In (C) there is excellent wall apposition of overlapping segments of both stents. In (D) a small amount of tissue prolapse through the stent struts is present (red arrows). In (E) the stent struts from the proximal stent are easily visualized with excellent apposition and expansion. In (F) the four radiopaque markers (black arrowheads) delineating the edges of the stent are distinguishable from the stent struts. The entirety of the vessel wall is visible in all sections. Three-dimensional FDOCT (G) shows excellent FDOCT correlation in the appearance of the stent and proximal markers compared with a high-resolution photograph (H).

Figure 3

Cross-sectional frequency-domain optical coherence tomography (FDOCT) images within the right vertebral artery (at the area of prior balloon angioplasty) just distal to (A) and at the level of the posterior inferior cerebellar artery (PICA) (B) show pathologic intimal thickening corresponding to a 28% residual stenosis. Stenosis analysis (C) and longitudinal views (D) show the severity of the stenosis based on proximal and distal reference vessels. The origin of the PICA (red arrows) is shown just proximal to the stenosis. Dashed circles in (C) and (D) correspond to the cross-sections in (A) and (B). (E) Three-dimensional FDOCT reconstruction demonstrates the luminal contour of the stent-vessel construct without significant stenosis.