Over the past few years, I have instituted the following three key elements in my vascular surgery practice, resulting in more patients being treated and better perioperative and long-term outcomes: (1) an annual aneurysm screening program, (2) an imaging software system to process and clearly understand a particular anatomic situation, and (3) the use of next-generation endografts, such as the Endurant® stent graft system (Medtronic, Inc., Minneapolis, MN).

THE EVOLUTION OF EVAR

The evolution of aortic endovascular therapies over the past decade has been dramatic, especially in the imaging field. Accurate preprocedural imaging, improvements in intraoperative technology, and new endograft technologies for increased deployment accuracy and stent graft placement have established endovascular aneurysm repair (EVAR), versus open surgical repair, as the ideal procedure. More than 20 years ago, the first EVAR procedure was performed in Buenos Aires; it is encouraging to see that EVAR has passed the test of time.

Today, next-generation endografts offer new designs and features that allow treatment options for an expanded range of patient anatomies. Precise, low-profile, and more flexible off-the-shelf devices allow us to reduce the incidence of type I endoleaks in elective procedures. The M-shaped nitinol wire stents in the Endurant® stent graft system provide flexibility and conformability during deployment. The tip-capture delivery system ensures accurate, controlled release during suprarenal stent deployment. In the last 2 years, we have implanted 70 Endurant devices with a very low complication rate.

ANNUAL ANEURYSM SCREENING PROGRAM

Since 2009, we have organized a multidisciplinary program aimed at increasing the early detection of aortic aneurysms at our university hospital. To increase awareness of our program, we developed an educational website (www.aneurismadeaorta.com), and in just 4 years, we have logged more than 20 million pageviews and more than 65,000 unique visitors throughout Latin America.

We also organized Semana del Aneurisma de Aorta (Aortic Aneurysm Week) to invite men between 60 and 80 years of age for abdominal aortic aneurysm (AAA) screening. More than 1,500 ultrasounds were performed, identifying more than 100 AAA patients. We noted two key factors for ensuring success in our AAA screening program: (1) a high initial rate of attendance to the screening program and (2) rapid access to treatment without delays in completion of the procedure, while maintaining a low operative mortality rate. We are now expanding our focus to raise AAA disease awareness within the neighboring peripheral community. To further advance this initiative, we sought external support.

ADDRESSING AAA FROM PRODUCT PIPELINE TO PATIENT

Over the last few decades, Medtronic has made significant investments toward advancing clinical understanding of aortic aneurysms. In the past, successful investigation of a disease was often directly associated with the size of the potential patient population. Medtronic has taken a global approach toward the understanding of aortic disease, demonstrating a commitment to improving endovascular techniques and patient outcomes through investments in screening, training, imaging and innovative products and technologies.

The goal of an AAA awareness program is to reduce mortality rate through early detection. Cancer and heart disease are familiar to most people. Public awareness of aortic aneurysm disease, on the other hand, lags behind. Further, although aortic disease prevalence is high, the majority of developing countries currently do not have strategies in place to screen, detect, and treat aortic aneurysm disease. It takes great effort and time to spread the concept that one simple abdominal ultrasound provided using university, public, and/or private resources can save a life. In the last 3 years, we organized three campaigns identifying nearly 100 aneurysm patients. This is a robust start, but we know that our effort will fade if it is not spread beyond academia. Medtronic holds our shared vision and is pursuing this goal through the awareness campaign, “detectA, actúA, vivA” (detect, act, live). These campaigns are spreading throughout Latin America to fight this so-called silent killer.

Ambitious projects supported by Medtronic have been launched in Puerto Rico, the Dominican Republic, and Costa Rica, with the joint action of the medical and general communities. Medical schools, associations, media, institutions, and public and private efforts have unified to help control this disease. Research has demonstrated that offering ultrasound screening to men at age 65 could reduce the rate of premature death from ruptured AAAs by up to 50% (level Ia, recommendation A).1-5 The objectives of the screening program are to identify eligible men and invite them for screening to accurately identify aortic aneurysms and provide patients with clear, high-quality information. The program should also minimize the adverse effects of screening, including anxiety and unnecessary investigations.

The program typically involves an ultrasound scan at community health care facilities such as hospitals, clinics, mobile units, and primary care facilities. To increase patient and community awareness of aortic disease and of the screening events, we distribute pamphlets, invitation letters and posters throughout the community. Banners and posters highlighting the screening event are also prominently displayed. All of these materials are available and provided by the awareness campaign (detectA, actúA, vivA) for display in general practitioner offices, primary care facilities, and other suitable public locations. Information sheets are also available at www.detectAAA.com.

In addition to a robust aneurysm screening program, enhanced imaging tools are critical in properly diagnosing and treating aneurysm disease.

ENHANCED IMAGING TO ELEVATE AAA SCREENING

EVAR imaging technology has evolved rapidly. The gold standard for preoperative evaluation of an aortic aneurysm is computed tomography angiography. Threedimensional (3D) reconstruction and analysis of the computed tomographic dataset is enormously helpful, and even sometimes essential, for proper sizing and planning of endovascular stent graft repair.

Medtronic's CTeXpress® is a web-based documentacquisition program that enhances today's complex imaging technologies. 3D Recon (Vital Images, Inc., Minnetonka, MN) was specifically designed to rapidly transfer large digital imaging and communications in medicine (DICOM) data and provide multiplanar renderings in real time. It provides advanced postprocessing techniques in 2D and 3D. The program automatically performs various image processing steps, such as bone removal and detection of an automated centerline. It offers advanced clinical tools for volumetric imaging modalities for visualization, interpretation, quantitative analysis, planning, and follow-up.

To supplement preprocedure case planning, the CTeXpress (Intelemage, LLC, Cincinnati, OH) web portal allows users to manage their images and case files. This program can create and modify orders, as well as communicate with other users, allowing them to securely upload images for central laboratory technical review. It offers real-time collaboration with Medtronic experts and international Key Opinion Leaders and creates a database of stored images for individual physicians to review at later dates with no cost, allowing online access from anywhere.

In recent years, we have seen a dramatic improvement in the technology used to visualize anatomy and aneurysms. This has resulted in the creation of more flexible, adaptable, and precise endografts that conform to patient anatomy, which has in turn improved clinical outcomes. The diseased anatomy of the aorta is more important than physiological status in predicting the success of endovascular intervention. The shape of the neck, the angle of the neck, and the relationship of the renal arteries to each other and their position in the neck play an important role at the time of stent graft deployment.

More complete preoperative information yields better intraoperative results. Segmentation and 3D vessel volume allow a better understanding of the anatomy, resulting in better planning, enhanced patient selection, and AAA measurement (3D double-oblique multiplanar reconstruction, 3D maximum intensity projection, or 3D curved multiplanar reconstruction). Three-dimensional branching parameters at visceral and aortic bifurcation sites, as well as blood vessel tortuosity, were determined from centerlines derived from computed tomographic angiograms (Figure 1).

Since the early days of EVAR, planning for infrarenal AAA repair has centered on anatomical assessment of the landing zones (aortic neck and iliac arteries) and access vessels. Misrepresented planar projections of branch trajectory, vessel length, and tortuosity demonstrate the importance of 3D geometric characterization. This information is useful not only for endovascular procedure case planning, but also for providing endovascular device design parameters.

PARTNERING TO ADVANCE THE PRACTICE OF EVAR

In Argentina, a recent report showed that there are 10 approved stent grafts for the treatment of AAAs. According to the National Administration of Drug, Food, and Medical Technology (ANMAT), this is more than double the figure recorded only 6 years ago. Not only has the number of available devices increased but so has the total number of aortic repairs and elective endovascular procedures.6 In this dynamic environment, it has become even more critical for physicians to challenge medical device manufacturers to provide solid clinical evidence to support the claims of their products. The burden of proof lies with the manufacturers to demonstrate whether changes in device design have translated to meaningful advances in clinical outcomes.

Stent graft technology is constantly evolving, and vascular specialists are gaining greater experience in treating increasingly complex pathologies. New device designs and deployment techniques have allowed treatment in the aortic arch and in the juxtarenal aorta, which was not previously possible. There is no doubt that EVAR will continue playing an increasing role in the treatment of patients with AAAs. The benefits of EVAR have been widely recognized by clinical practices, and thousands of cases are performed every year. Advances in medical imaging have also played an essential role in improving both planning and postoperative efforts.

Medtronic is recognized as the world leader in medical technology and pioneering therapies. With Endurant—designed through a mutidisciplinary approach that incorporated feedback from more than 150 physicians—Medtronic has set the standard for the rigorous device design and validation process.7 Clinical evidence on the Endurant stent graft indicates that the Endurant design attributes have translated into meaningful clinical outcomes for patients.

By enabling research and innovation through physician partnerships, corporate sponsors like Medtronic can continue to advance EVAR therapy. Corporate collaboration expands our ability to influence development across the industry, to advance our research and work, and to deliver evidence-based practice and innovation to a growing segment of health care services.

L. Mariano Ferreira, MD, is vascular surgeon and endovascular specialist at the Hospital de Clínicas and ENERI/ Clínica La Sagrada Familia in Buenos Aires, Argentina. He has disclosed that he receives honoraria from Medtronic, Inc. for consulting, speaking, and training. Dr. Ferreira may be reached at +5411-4783-9122; drferreira@yahoo.com.

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