Novel EM Guided Endovascular Instrumentation for In Situ Endograft Fenestration.

S Condino,R N Berchiolli,D M Mocellin,R Piazza,R Pini,F Micheletti,M Ferrari,V Ferrari,F Rossi,G Turini,R M Viglialoro

doi:10.1109/jtehm.2020.2973973

Abstract

Objective: This work aims at providing novel endovascular instrumentation to overcome current technical limitations of in situ endograft fenestration including challenges in targeting the fenestration site under fluoroscopic control and supplying mechanical support during endograft perforation. Technology: Novel electromagnetically trackable instruments were developed to facilitate the navigation of the fenestration device and its stabilization at the target site. In vitro trials were performed to preliminary evaluate the proposed instrumentation for the antegrade in situ fenestration of an aortic endograft, using a laser guidewire designed ad hoc and the sharp end of a commercial endovascular guidewire. Results: In situ fenestration was successfully performed in 22 trials. A total of two laser tools were employed since an over bending of laser guidewire tip, due to its manufacturing, caused the damage of the sensor in the first device used. Conclusions: Preliminary in vitro trials demonstrate the feasibility of the proposed instrumentation which could widespread the procedure for in situ fenestration. The results obtained should be validated performing animal studies. Clinical Impact: The proposed instrumentation has the potential to expand indications for standard endovascular aneurysm repair to cases of acute syndromes.

Highlights

Endovascular aortic aneurysm repair (EVAR) is a popular, minimally-invasive surgical technique for treating abdominal aortic aneurysms (AAAs)
The final accuracy will be mainly affected by three sources of error: the EM tracking, which may be adversely affected by interference arising from the environment; the calibration of the sensorized instruments; the reconstruction of the 3D poses of aorta branches from EM coils embedded in the μEMg
in situ fenestration (ISF) is an intraoperative technique developed to avoid the intrinsic delays in the fenestrated endograft manufacturing process and to offer a bailout alternative in case of side branch occlusions

Summary

Introduction

Endovascular aortic aneurysm repair (EVAR) is a popular, minimally-invasive surgical technique for treating abdominal aortic aneurysms (AAAs). The main idea of this work is to provide the surgeon with EM guided endovascular instruments designed so that their 3D pose (i.e. position and orientation) can be accurately tracked in real-time This allows the visualization of virtual tool replicas within a 3D model of the patient vasculature. Such anatomical model can be generated by the segmentation of an intraoperative 3D dataset (e.g. with a calibrated rotational C-arm) acquired before the endograft deployment for a complete 3D reconstruction of the target aorta branches. This method allows the visualization of the aorta branches before and after endograft deployment, since it does not rely on the use of fluoroscopy and contrast agent. Miniaturized EM coils can be used for the real-time tracking of the guidewire and the catheter, and to reconstruct the distal curvature of the latter, as in [9]

Methods

Results

Discussion

Conclusion