Stent-Graft Repair

Editor's Corner

Submitted on Fri, 09/05/2008 - 16:36
Authors

Frank J. Criado, Editor-in-Chief

Diseases of the thoracic aorta are relatively frequent and often life-threatening. Degenerative thoracic aneurysms (TAA) and aortic dissection (AD) are the most common and best-known, but a number of other significant lesions are also encountered (such as penetrating ulcers, intramural hematoma, pseudoaneurysms following trauma or surgery, traumatic transections, etc.) that carry the same dire natural-history implications. Surgical repair has been at the center of the standard of care for many years. Unfortunately and in spite of the impressive advances in intra and post-operative management achieved over the past 10–15 years, thoracic aortic surgery still carries very high morbidity and significant mortality. Additionally, many patients are at high or prohibitive-risk for open surgery, and surgeons are (understandably) somewhat reluctant to offer operative treatment in a significant number of cases. Lastly, optimal surgical thoracic expertise, with high volumes and excellent outcomes are not in abundance. All these factors, combined, create a rather unfavorable scenario for — perhaps — the majority of patients with TAA and other thoracic aortic diseases. Many remain undiagnosed and/or untreated. The need for and desirability of less-invasive, alternative treatment options is self-evident. The endovascular thoracic evolution begun in 1994 when stent-graft repair was first reported by Dake et al.1 from Stanford. Beginning with homemade devices, and having gone through first-generation commercial endografts, we have at present second- or third-generation devices that constitute viable tools for non-surgical endovascular repair in many patients with thoracic aortic diseases. At present, large experience (>100 implants) has been accumulated in perhaps 30–40 centers worldwide. The whole field is now growing very rapidly, and device refinements and new technologies are a sure prediction for the near future. Many unanswered questions and unresolved issues remain, but much has been learnt and achieved over a decade’s worth of experience. With the exceptions of ascending aortic and total arch involvement, a majority of TAA, type B dissections, and many other lesions would seem to be amenable to endograft repair. In our service, we have now gained experience with >220 thoracic endograft implants. The following examples illustrate the state-of-the-art in endovascular thoracic repair (Figures 1–5). Brief Discussion and Overview We are convinced thoracic aortic repair is the best and most exciting clinical application of endograft technology. Rapid advancements in device design and interventional strategies are sure bets for the near future, with likely profound impact on the whole field of thoracic aortic surgery. And the reach of these developments will not be bound proximally by the origin of the innominate artery for much longer. In some cases, ascending aortic and even total arch involvement will be addressed by endovascular means in the future. As of this date (December 2004), all thoracic stent-graft devices remain investigational in the U.S. FDA approval of the first stent-graft (TAA indication) is anticipated for Q2–3 ‘05. Others will follow later in 2005 and beyond. In our current practice, we treat acute and chronic dissections, TAA, penetrating ulcers, and several other disease states on patients with suitable anatomy for endovascular repair. We are fortunate to have the regulatory mechanisms at our disposal for patient enrollment in every instance. For some challenging situations, hybrid combinations of surgical reconstruction and endovascular intervention tend to work quite well. This is particularly pertinent for cases where preliminary arch branch transpositions or bypasses can be performed in order to gain proximal length within the aortic arch for endograft fixation and seal (Figures 1–3). Frank J. Criado, Editor-in-Chief Director, Center for Vascular Intervention; Chief, Division of Vascular Surgery; Union Memorial Hospital/MedStar Health, Baltimore, MD; frank.criado@medstar.net