Development of a Preoperative Simulation Technique for Carotid Endarterectomy in Patients with Contrast Contraindications.

Abstract

Vascular and osteological parameters, such as the heights of the carotid bifurcation and distal end of the plaque, are important preoperative considerations for patients undergoing carotid stenosis procedures, such as carotid endarterectomy. However, for patients with contraindications to contrast media, such as allergies or nephropathies, 3-dimensional computed tomography angiography (3D-CTA) is unavailable, and preoperative evaluation remains challenging. In the present study, we aimed to develop a preoperative simulation for use in patients with contrast-contraindicated carotid stenosis. Images from noncontrast neck computed tomography scans and magnetic resonance imaging obtained without the Leksell stereotactic frame were uploaded to GammaPlan. Following delineation of various structures, preoperative simulations were performed to determine the relationships between vascular and osteological structures. We applied this technique in 10 patients with carotid stenosis to verify the accuracy of the simulation. In all patients, the GammaPlan simulation successfully visualized the heights of the carotid bifurcation and distal end of the plaque without the use of contrast medium. Furthermore, information regarding the location of internal arterial structures, such as calcifications and unstable plaques, could be incorporated into GammaPlan images. We verified simulation accuracy by comparing the simulation results with 3D-CTA and operative findings. Simulations created using GammaPlan can be used to obtain accurate vascular and osteological information regarding the heights of the carotid bifurcation and distal end of the plaque, without the use of contrast medium. The reconstruction of delineated structures using this technique may be effective for preoperative evaluation in patients with contrast-contraindicated carotid stenosis.