**2. Access and technique**

The endovascular procedure is usually performed through the femoral arteries [1-3]. Some‐ times this access is impossible or not recommended because of small size vessels, obstruction, calcification, dissection or extreme tortuosity.

The feasibility of endovascular treatment depends on many anatomic factors, including the diameter and the disease state of the access vessels [4,5]. Stenosis, calcifications, tortuosity, small size or dissection in both femoral and iliac arteries can make introduction of large sheath hazardous or impossible.

© 2013 Saadi et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Endoprosthesis deployment in the ascending aorta usually requires large diameter and long sheath. There is always possibility of damaging the aortic valve, since the nose of the com‐ mercially available devices is designed for descending and/or abdominal aorta. The vascular prosthesis should be large enough to oversize by 15-20 % the aortic diameter and short in length to fit between the coronary arteries and the brachiocephalic trunk. This length usually measures 8 cm or less. The endovascular technique would have several advantages over the open surgical alternatives if the right tools for the procedure were available. Current thoracic aortic stent-grafts are too long, while abdominal aortic stent-grafts are too short and narrow. Moreover, abdominal aortic delivery systems are too short to traverse the long and tortuous path from the femoral artery to the ascending aorta.

Several different approaches have been presented and published over the last years as an attempt to solve very dramatic situations stretching the limits of the current technology [6-8].

The technique should be carefully planned. Rapid pacing and adenosine are useful to lower blood pressure and allow precise deployment. A rigid (Landerquist or super stiff) and long (260 cm) guidewire is usually placed in the left ventricle to give adequate support near the coronary arteries. This is similar to what we use when performing transcatheter aortic valve implantation (TAVI). One important tip is to perform a "wide J-shape" at the end of the rigid guidewire in order to prevent left ventricule perforation and, consequently, cardiac tamponade or left ventricular pseudoaneurysm.

**Figure 1.** Aortogram showing bovine trunk and a pseudoaneurysm in the anterolateral wall of the ascending aorta 1

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**Figure 2.** Final aortogram of emergency endovascular correction of a pseudoaneurysm through transfemoral implan‐ tation of a Cook endoprosthesis. The shorter device we had available was a 8 cm length endoprosthesis. In order to preserve flow in the brachiocephalic trunk and left carotid artery (bovine trunk) we had to use a chimney (snorkel)

technique in this two vessels arch using two Viabahns to preserve flow.

cm above the ostium of the right coronary artery.

Similar to other endovascular procedures, besides careful planning, patient selection and technical expertise are crucial to obtain satisfactory results. In this setting multidetector computed tomography (MDCT) plays an important role in selecting the patients suitable for the procedure and allows a careful and detailed step by step preoperative planning.

We have recently published a series of five clinical cases and described the technique in which the axillary artery was used to deliver the endograft for the treatment of different thoracic aortic diseases [9]. We also demonstrated the possibility of concomitant treatment of ascending aorta disease and coronary stent implantation [10,11].

Transcarotid is another alternative access and, recently, transapical approach through a small left thoracotomy has been described.
