LIMITATIONS
This study is limited by its retrospective nature and by referral bias inherent in a single specialty center study. Statistical significance of predictors of adverse outcome could not be achieved due to low number of adverse events and overall relatively small cohorts. The results reported in this study are representative only of referral centers with concentrated experience in these procedures.
Despite advantages in the approach to the mega-aorta, there are also certain inherent disadvantages of the Two-Stage elephant trunk procedure. (a) Stage I requires a suitable landing zone in the aortic arch for the elephant trunk anastomosis. Although workable neck is usually able to be found, this can be problematic in the advanced mega aorta. In our practice, we use the Sienna graft for such cases; the Sienna graft has a “skirt” that can accommodate virtually any aorta. (b) The elephant trunk can be difficult to engage at a second stage endovascular completion. We have uniformly used an open second stage. Also, grafts are now available in Europe (E-Vita (Jotec) and Thoraflex (Terumo)) and under investigation in the United States that can be deployed at the time of the original procedure to stent the descending aorta (albeit incurring a risk of paraplegia with all but the shortest grafts)[16].