Electromagnetic tracking for registration and navigation in endovascular aneurysm repair: a phantom study

To assess the feasibility of using an electromagnetic tracking for both registration and navigation in endovascular aneurysm repair.

A registration process was implemented to align computed tomography (CT) data and electromagnetic tracking data. Two abdominal aortic aneurysm (AAA) phantoms were used, a rigid plastic AAA model (phantom A) and a soft silicon AAA model (phantom B). A pre-procedural CT volume was acquired for each phantom. Intra-operative simulation was performed by placing each phantom in the magnetic field of the tracking device. Using a modified electromagnetic catheter, a set of three-dimensional positions was acquired in the phantom's aortic lumen. Pre-procedural CT images and intra-procedural tracked positions were registered. Four reference points were used to calculate the registration accuracy of phantom A. Three surgeons simulated catheterisation of the left renal artery with phantom B using only image-guided procedure software.

The mean registration error was 1.3 mm (range 0.88-1.89). The median time for left renal catheterisation was 22 s (range 15-59).

Registration of CT data and electromagnetic tracking data is feasible using catheter positions in the aorto-iliac structure as landmark. This navigation system could reduce X-ray exposure time and the use of contrast medium injections.