With improved graft performance and recent technical evolution, endovascular repair is becoming the first-line treatment for a broad range of thoracic aortic disease etiologies. Nevertheless, there are still some cases in which the native aortic anatomy is challenging or even prohibitive. In particular, native arch anatomy can be deemed unsuitable, as short neck lengths, tortuosity, and angulation may result in imprecise deployment and endoleak due to lack of stent graft conformability. The Valiant Thoracic Stent Graft on the Xcelerant Delivery System (Medtronic, Inc., Minneapolis, MN) has been broadly available outside the United States since 2005, with over 22,000 patients treated worldwide in just 5 years of clinical experience. It has emerged as a preferred thoracic stent graft mainly due to its hallmark feature of conformability, broad patient applicability, and ease of use.

THE CAPTIVIA DELIVERY SYSTEM
The Captivia Delivery System, used in conjunction with the Valiant Thoracic Stent Graft (Figure 1), received CE Mark approval and was introduced in September 2009. The Captivia Delivery System has several key features that may contribute to the successful introduction, delivery, placement, and conformability of the stent graft in challenging thoracic aortic anatomies. First, the addition of hydrophilic coating on the graft cover of the delivery system facilitates vascular access and enhances stent graft delivery through tortuous iliac and aortic courses (Figure 2). Second, the dual control of the delivery system allows partial deployment with the opportunity to reposition for precise placement, which is especially important when accurate placement in short landing zones is critical (Figure 3). Third, the tip capture feature further enhances control during proximal stent graft deployment, avoiding the windsock effect and stabilizing the graft at the targeted landing zone (Figure 4). These new features associated with the Captivia Delivery System in combination with the Valiant Thoracic Stent Graft are designed to expand treatment to more patients with complex aortic disease and ultimately improve patient outcomes.

REGISTRY DESIGN
A postmarket registry to collect and evaluate short- and midterm clinical performance of the Valiant Thoracic Stent Graft with the Captivia Delivery System is being conducted in Europe and Turkey. Sixteen centers have enrolled 100 patients with a variety of conditions such as thoracic aortic aneurysm, type B dissection, penetrating aortic ulcer, and blunt aortic injury. Patients are followed per standard of care at the investigational sites with imaging and clinical follow- up.

The primary endpoints of the registry are technical success at the time of implant and treatment success at 12 months. In addition, a 30-day analysis is being conducted to evaluate acute performance. Technical success is defined as successful delivery and deployment of the stent graft (assessed intraoperatively) in the planned location with no unintentional coverage of the left subclavian artery, left common carotid artery, and/or brachiocephalic artery and with the removal of the delivery system. The secondary endpoints for the 30-day analysis are procedural complications at the time of implant, including misaligned deployment and aortic perforation, and clinical outcomes within 30 days of implantation, including all-cause mortality, paraparesis/paraplegia, secondary endovascular procedures due to an endoleak after discharge, and one or more major adverse events.

RESULTS
This report summarizes the 30-day analysis of the first 50 subjects enrolled. One hundred percent of this 30-day data has been monitored to ensure compliance with the clinical investigation plan and to assess the accuracy and completeness of submitted clinical data. Among the first 50 patients, there were 39 men and 11 women (mean age, 64. 2 ± 13). Aneurysm and dissection were the most common disease etiology, with 20% of acute type B dissection, but traumatic transection and pseudoaneurysm were also present. Comorbidities and preexisting conditions were present in more than 50% of patients, including hypertension, previous cerebrovascular accident, dyslipidemia, abdominal aneurysm, and Marfan syndrome. Anatomical characteristics showed a mean diameter of 53 mm (± 14.8 mm), a mean aneurysm extension of 109 mm (± 96 mm), and a mean proximal neck length of 34.8 mm (± 34.5 mm). Interestingly, in five patients, the proximal neck length was less than 10 mm, and two out of 50 patients had a diameter of the femoral/iliac arteries less than 7 mm.

Deployment was successful at the intended landing zone in all patients without migration or twisting. At 30-day follow-up, there were no observations of type I or type III endoleak. The left subclavian artery was covered in 25 of 50 patients (of which none were unintentional), 12 of whom had previous revascularization. Clinical outcome at 30 days showed a mortality rate of 6%, an incidence of stroke of 8%, and a paraplegia rate of 2%. These data are in line with previous reports, considering 20% of this patient cohort was treated for acute, complicated type B dissection.

CONCLUSION
The interim analysis of the first 50 patients treated with the Valiant Thoracic Stent Graft with the Captivia Delivery System confirms high device conformability that is able to adapt to a broad range of patient anatomies, with no incidence of misaligned deployment or twisting. Hydrophilic coating facilitated iliac access and stent graft delivery, which was exemplified in two patients who had ≤ 7-mm femoral arteries. Early outcomes confirm stent graft reliability with no incidence of endoleak or migration.

Rossella Fattori, MD, is Professor and Cardiovascular radiologist in the Cardiothoracovascular Department at University Hospital S. Orsola, in Bologna, Italy. She has disclosed that she holds no financial interest in any product or manufacturer mentioned herein. Dr. Fattori may be reached at rossella.fattori@unibo.it.