Aortic roadmapping during EVAR: a combined FEM-EM tracking feasibility study

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Computational Mechanics

Background:

• Intra-operative visualization in endovascular aneurysm repair (EVAR) currently relies on contrast-based imaging.
• Traditional image fusion techniques fail to account for dynamic vessel changes caused by guidewire insertion.
• Accurate real-time vessel mapping is crucial for safe and effective EVAR procedures.

Purpose of the Study:

• To develop and evaluate a novel image fusion approach combining electromagnetic (EM) tracking and finite element modeling (FEM).
• To improve intra-operative visualization by accounting for vessel deformations during EVAR.
• To enhance the accuracy of the predicted aortic roadmap for improved surgical navigation.

Main Methods:

• A patient-specific abdominal aorta model was created for segmentation and manufacturing.
• A database of numerical simulations with varying insertion angles was generated.
• An ad hoc tool with embedded EM sensors was designed for tracking during guidewire insertion.
• Cone beam computed tomography (CBCT) images were acquired to determine ground truth aortic deformations.

Main Results:

• The simulation that minimized the discrepancy between in silico predictions and in vitro sensor positions yielded the most accurate aortic displacement results.
• The integration of EM tracking data improved the predictive accuracy of the numerical simulations.
• Validation against CBCT-derived ground truth demonstrated the efficacy of the proposed method.

Conclusions:

• EM tracking technology can be utilized to minimize errors in predicted aortic roadmaps during EVAR.
• The combined EM tracking and FEM approach offers a promising solution for real-time, deformation-aware image fusion.
• This novel method has the potential to significantly enhance the safety and precision of EVAR procedures.