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Proximal Landing Zone Extension for TEVAR
In this issue of the Journal of Invasive Cardiology, Drs.Vaghetti et al1 from Italy have presented their 10-year experience with thoracic endovascular aortic repair (TEVAR) for acute aortic syndromes (AAS). They describe their experience with the use of stent grafts for acute aortic dissections (Stanford type B), penetrating aortic ulcers (PAU), ruptured aortic aneurysms and aortic transactions. In a subgroup of their patients, aortic arch vessel debranching was necessary in order to provide an adequate proximal seal/landing zone for the stent.
The authors need to be congratulated on their case series. Although the use of stent grafts has been rapidly evolving, it has not been until relatively recently that TEVAR has developed into a practical strategy for treatment of thoracic aortic pathology; furthermore, the use of TEVAR for AAS is only recently emerging not only as an acutely viable option, but also as a durable long-term strategy for patients that usually have advanced comorbidities.
Despite the growing trend towards a fully percutaneous approach to TEVAR (and endovascular aortic repair – EVAR), the interventional cardiologist should never perform these in isolation. The authors on the current study represent cardiologists and cardiovascular surgeons. Although, the pathophysiology of AAS can be well understood by any single discipline, the complications — acute coronary, aortic or vascular — are best dealt with in a collaborative and multidisciplinary environment in a hybrid operating room. Furthermore, each discipline brings a unique skill set and perspective to the approach and care of the patient.2 All of these procedures were performed in the cardiac catheterization laboratory. This highlights an emerging trend that complex endovascular procedures, including those requiring hybrid surgical procedures, can be done in the cardiac catheterization lab. An important caveat is that the lab should truly be a hybrid lab capable of open surgical conversion, as was necessary in one patient in this series or to perform debranching techniques.
In this series, there were no cases of clinically significant spinal cord ischemia. It is important to have a proactive and low threshold for prevention of this potentially devastating complication. In our patients, we prophylactically place a spinal cord drain, maintaining a pressure of < 11 mmHg, when we anticipate covering the majority of the descending thoracic aorta (so-called “paving the aorta”) or if there has been prior aortic surgery (e.g., abdominal aortic aneurysm repair). We also seek to avoid hypotension at all costs during the procedures. Both of these maneuvers theoretically maintain a higher spinal cord perfusion pressure.
As demonstrated in this series, aortic debranching extends the anatomic landing zone and expands the number of potential patients who are candidates for TEVAR. In such cases where the left subclavian artery is intentionally covered, but not bypassed, it is crucial to document a patent circle of Willis in order maintain limb perfusion.
In summary, the authors present very robust data supporting their multidisciplinary endovascular approach to AAS. They elegantly presented their approach to a very complex set of patients and anatomic considerations. A subset required aortic arch debranching which allowed for the anatomic extension of the proximal landing zone. Their outcomes confirm their thoughtful approach to TEVARs for AAS.
References
- Vaghetti M, Palmieri C, Al-Jabri A, et al. Endovascular treatment of acute thoracic aortic syndromes with a proximal landing zone extension strategy. Procedural and follow-up results. J Invasive Cardiol 2011;23:187–192.
- Dieter R. Treatment of thoracic aortic pathology. Presentation at the American College of Cardiology Annual Scientific Sessions, 2009.
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From *Hines VA Cardiology and the £Department of Cardiology, Vascular Medicine and Peripheral Interventions, West Virginia University, Charleston, West Virginia; and §Interventional Cardiology Research, Loyola University, Stritch School of Medicine, Maywood, Illinois.
Address for correspondence: Robert S. Dieter, MD, RVT, Assistant Professor, Department of Medicine, Loyola University, Stritch School of Medicine and Hines VA, 2160 S First Avenue, Bldg. #110, Rm# 6289, Maywood IL 60153. E-mail: rdieter@lumc.edu
