Increased Cell Opening and Prolapse of Struts of a Neuroform Stent in Curved Vasculature:Value of Angiographic Computed Tomography: Technical Case Report

Abstract

To describe the use of a new imaging tool, angiographic computed tomography, for visualization of cell opening and strut prolapse of a Neuroform 2 stent (Boston Scientific/Target, Fremont, CA) placed in curved vasculature for treatment of a basilar tip aneurysm. A 46-year-old woman presented with an unruptured 8-mm basilar tip aneurysm with a wide patulous neck. A 4 x 20-mm Neuroform 2 stent was placed across the aneurysm neck. Angiographic computed tomographic scanning was performed using a flat detector biplane angiographic system with new commercially available software (Dyna-CT; Siemens Medical Solution, Forchheim, Germany) and the following parameters: 20-second acquisition, 0.4-degree increment, 512 matrix in projections, 220-degree total angle, 20 degree/s, and approximately 15 to 30 frames/s, for a total of 538 projections. Image postprocessing was performed to correct scattered radiation, beam hardening, and ring artifacts on a commercially available workstation (Leonardo, Siemens Medical Solutions, Erlangen, Germany). The aneurysm was coiled in a second session, using bare platinum coils without clinical sequelae. Increased opening of cells and prolapsing of struts of an open cell design stent can occur after placement in a curved vessel across an aneurysm orifice. Angiographic computed tomography is a new imaging tool that provides visualization of intracranial stents that is superior to digital subtraction angiogram or nonsubtracted images. It will enhance our understanding of stent behavior in clinical practice and improve the efficacy and safety of intracranial stent placement. Further in vitro and in vivo imaging studies of intracranial stents are necessary to assess the value of this promising new technique.