Three-dimensional guidance including shape sensing of a stentgraft system for endovascular aneurysm repair

Abstract

Purpose During endovascular aneurysm repair (EVAR) procedures, medical instruments are guided with two-dimensional (2D) fluoroscopy and conventional digital subtraction angiography. However, this requires X-ray exposure and contrast agent is used, and the depth information is missing. To overcome these drawbacks, a three-dimensional (3D) guidance approach based on tracking systems is introduced and evaluated. Methods A multicore fiber with fiber Bragg gratings for shape sensing and three electromagnetic (EM) sensors for locating the shape were integrated into a stentgraft system. A model for obtaining the located shape of the first 38 cm of the stentgraft system with two EM sensors is introduced and compared with a method based on three EM sensors. Both methods were evaluated with a vessel phantom containing a 3D-printed vessel made of silicone and agar-agar simulating the surrounding tissue. Results The evaluation of the guidance methods resulted in average errors from 1.35 to 2.43 mm and maximum errors from 3.04 to 6.30 mm using three EM sensors, and average errors from 1.57 to 2.64 mm and maximum errors from 2.79 to 6.27 mm using two EM sensors. Moreover, the videos made from the continuous measurements showed that a real-time guidance is possible with both approaches. Conclusion The results showed that an accurate real-time guidance with two and three EM sensors is possible and that two EM sensors are already sufficient. Thus, the introduced 3D guidance method is promising to use it as navigation tool in EVAR procedures. Future work will focus on developing a method with less EM sensors and a detailed latency evaluation of the guidance method.

Instrument localisation for endovascular aneurysm repair: Comparison of two methods based on tracking systems or using imaging

“…These measured errors are higher than in previous experiments with the same multicore fibre. [23][24][25] One reason for that might be that the stentgraft system was rotated during insertion and pressure was applied at the insertion sheath. This could have introduced a twist of the fibre and thus resulted in higher errors.…”

Three-Dimensional Holographic Guidance, Navigation, and Control (3D-GNC) for Endograft Positioning in Porcine Aorta: Feasibility Comparison With 2-Dimensional X-Ray Fluoroscopy

“…Electromagnetic (EM) tracking provides real-time (ie, live) locational tracking of endoluminal devices without the harmful effects of ionizing radiation. 4 The EM navigation system is attached to the surgical table and generates a weak magnetic field around the patient. The delivery system is equipped with an EM sensor that detects relative changes in a set of magnetic field generator coils to track its position and orientation (P&O) of the delivery system.…”

Catheter pose-dependent virtual angioscopy images for endovascular aortic repair: validation with a video graphics array (VGA) camera

“…To reduce EVAR limitations, a recent study reported the integration of a multicore fiber with fiber Bragg gratings and two electromagnetic (EM) sensors into a stent graft system to locate the shape of the endovascular tool with respect to the patient's anatomy (in that case, a patient-specific aortic phantom) [1]. In addition, virtual angioscopy images were rendered based on the pose (position and orientation) of an EM-tracked catheter tip [2].…”

“…These images of the vessel lumen were visualised on a virtual 2D canvas superimposed on the real scenario with the augmented reality glasses Microsoft HoloLens (first generation). These previous studies [1,2] are part of our ongoing research project Nav EVAR.…”