Approaching complex aortic repairs with non-ionizing radiation.
By Anahita Dua, MD, And Matthew J. Eagleton, MD
Endovascular aneurysm repair (EVAR) has dramatically evolved over the past 2 decades—from relatively simple tubular endografts to extraordinarily complex branched endografts that allow endovascular coverage from the sinotubular junction through the iliac bifurcation. With this increasing complexity of repairs, parallel improvements in imaging and navigation technologies have ensued. These complex procedures have required increased fluoroscopy times, resulting in higher radiation dose exposure to both patients and operators. It has also necessitated the development and use of an increased number of various-shaped catheters, sheaths, and wires to cannulate target vessels. In addition, it has led to an increase in the amount of contrast doses administered during the course of the procedures as compared with more simple, standard aortic endovascular procedures. Although there has been some improvement in imaging systems during this time, we have still relied on two-dimensional (2D), grayscale, fluoroscopic images to drive these procedures. Image overlay technology has reduced contrast use, increased procedure speed, and reduced radiation doses.
In addition to these standard imaging technology and endovascular tools, there has been a growing interest in developing improved imaging capabilities, image visualization, and navigation through complex arterial trees, as well as more precise endograft placement—all using nonionizing radiation–based systems. These systems include intravascular ultrasound (IVUS), robotic-assisted placement of endovascular tools, and electromagnetic (EM) tracking of endovascular tools. The current evaluation of these modalities does not entirely negate the need for imaging modalities that rely on ionizing radiation, but the purpose of this article is to demonstrate clinical feasibility, improvements in operative imaging, and the potential to significantly improve the accuracy and safety of device placement and treatment of patients with aortic disease by using these new technologies.