A Five-Year Computed Tomography Follow-up Study of Proximal Aortic Neck Dilatation After Endovascular Aortic Repair Using Four Contemporary Types of Endograft

We thank Oliveira et al. for their comments [1] regarding limitations of our study on proximal aortic neck dilatation after endovascular aortic repair using four contemporary types of endograft [2]. In their letter to the Editor, these authors had a question regarding endograft oversizing for initial endovascular aortic repair (EVAR). As mentioned in the Study Design of our study, the proximal part of the main device, irrespective of the type of endograft, was oversized by 10–20% compared to the infrarenal aortic neck diameter (D2); in particular no difference in endograft oversizing was performed in between Ovation and Zenith cases. Another comment of the authors includes the predefined aortic diameter measurement level. It is clear that the diameter of the proximal infrarenal neck (D2) before and after EVAR was always measured just below the lowermost renal artery as demonstrated in our manuscript’s Fig. 1, which is the most cranial zone of the proximal aortic neck, covered by the endograft fabric. Indeed, in all EVAR procedures, regardless of the type endograft implanted, the fabric of the main body of the endograft entirely covers the proximal aortic neck and subsequently, the D2-measurement is performed in the covered part of the neck; in no cases there was misplacement of the main device resulting in an uncovered proximal part of the aortic neck. Last, the authors worry about the overall rate of late type IA endoleaks, which in our series is 5.8%. As mentioned in Table 3 of our manuscript, the mean and median diameter of the proximal infrarenal neck (level D2) before EVAR is not different among endograft groups; in addition the overall interquartile range of proximal neck diameters is in between 21.5 and 26 mm which cannot be considered as excessive neck dilatation. However, we agree that the number of late type IA endoleaks is relatively high in this series (5.8% overall) and was observed in three out of four endograft types. Here, the number of included patients per endograft group (n = 30) is too small to draw robust conclusions. …