Visualization of stent apposition after stent-assisted coiling of intracranial aneurysms using high resolution 3D fusion images acquired by C-arm CT

Abstract

PurposeWe used an imaging technique based on 3-dimensional (3D) C-arm CT to assess the apposition of three types of stents after coiling of intracranial aneurysms.MethodsAll patients with intracranial aneurysms were considered who received stent-assisted coiling with Enterprise2, Neuroform EZ, or Neuroform Atlas stents confirmed by C-arm CT imaging at our institution between June 2015 and November 2017. A 3D digital subtraction angiography (DSA) scan for vessel imaging followed by a high-resolution cone beam CT (HR-CBCT) scan for coil and stent imaging was performed. The images were fused to obtain dual volume 3D fusion images. We investigated malapposition of the stent trunk (crescent sign) and of the stent edges (edge malapposition) and used the χ2 statistic to test for an association with stent types. Inter-rater agreement between two raters was estimated using Cohen’s kappa statistics.ResultsWe evaluated 75 consecutive cases. Enterprise2 stents were used in 22 cases, Neuroform EZ in 26, and Neuroform Atlas in 27 cases. By stent type, crescent sign was detected in 27% of Enterprise2, 8% of Neuroform EZ, and none of Neuroform Atlas stents (p=0.007), while edge malapposition was detected in 27% of Enterprise2, 58% of Neuroform EZ, and 30% of Neuroform Atlas stents (p=0.05). Excellent (κ=0.81) and good (κ=0.78) agreement between the raters was found for the detection of edge apposition and crescent sign, respectively.ConclusionStent malapposition was clearly visualized by dual volume 3D imaging. The Neuroform Atlas stents showed good apposition even in vessels with strong curvature.

Effects of Enterprise 2 stent-assisted coil embolization for wide-necked intracranial aneurysms

“…Herweh et al [ 7 ] first studied the application of the EP2 stent in clinical patients and reported good safety and effectiveness; however, incomplete stent apposition still occurred in the vessels with a large curvature. Kato et al [ 14 ] used the double volume fusion technique based on C-arm CT to compare stent-vessel apposition of three stents (EP2, Neuroform, and Atlas) and found the frequency of crescent sign detection in the bending vessels was highest for the EP2 stent (27%, 8%, and 0, respectively). Chen et al [ 15 ] used VasoCT to observe EP2 stent release and reported that 6 of 25 stents (24%) showed malposition: 2 showed kinking and the other 4 showed large gaps between the stent and vessel wall.…”

Low-profile visualized intraluminal support Blue stenting within a Neuroform Atlas stent for a large wide-necked aneurysm: A case report and a bench-top experiment

“…Atlas has less metal volume than Enterprise and protrudes into the unconstrained segment. 8 Therefore, it is unlikely that LVIS expansion is affected within the Atlas. Since LVIS expansion was not restricted by the Atlas, the transition zone was shortened, which may have led to aneurysm occlusion.…”

Application of High-Resolution Flat Detector Computed Tomography in Stent Implantation for Intracranial Atherosclerotic Stenosis

“…HR-FDCT has helped improve stent visualization during neurointerventional procedures (Clarençon et al, 2017;Kuriyama et al, 2018;Srinivasan et al, 2018). Studies have explored its utility in patients with intracranial aneurysms [ (Caroff et al, 2014;Shintai et al, 2018;Kato et al, 2020). However, few reports have focused on the clinical application of HR-FDCT in stent placement for symptomatic ICAS.…”

“…However, patients who develop recurrent cerebral infarction or recurrent transient ischemic attacks (TIAs) despite optimal medical therapy may be considered for more aggressive treatment, including cerebral arterial angioplasty and/or stent placement (Qureshi and Caplan, 2014;Heit and Wintermark, 2018). Optimal visibility of the intracranial stent is limited using digital subtraction angiography (DSA) applications (Kato et al, 2020). Although some radiopaque elements of intracranial stents may be observed via fluoroscopy during treatment, local distortion or incomplete expansion of the stent may be difficult to identify due to limited angiographic angles or the presence of bony or metal obstructions (Li et al, 2019).…”