Reply to Polat and colleagues

Abstract

Polat and colleagues pose key questions about our study and the future of bespoke external aortic root support (EARS). The 66 patients excluded from analysis did not match prespecified criteria, namely a first-time, elective, aortic root operation, in the same time frame and setting. The 28 patients used for comparison had similar intraoperative myocardial ischaemic, cardiopulmonary bypass, and circulatory arrest exposure as 254 root replacements in Polat's experience.1 We have shown that EARS obviates these potentially harmful, but necessary, surgical adjuncts to root replacement.2 Will EARS prevent aortic dissection within the supported segment? Our expectation is that it will reduce both the risk of dissection and, should it occur, the severity of its consequences. We have already shown that EARS holds the supported aortic segment at, or smaller than, its preoperative size.3 The dimensions across the three aortic sinuses were measured on duplicate magnetic resonance images of 37 non-operated Marfan patients and before and after (>1 year) images of the first 10 EARS patients. The 96 images were presented in random sequence to a radiologist blind to their identity and to the hypothesis. The stability of the external support, predicted from the characteristics of the material and the engineered design, was confirmed.3 We agree that there is no threshold aortic root size that precludes dissection4-6 but the risk is size-related and is the reason expansion is monitored.7 There are benefits other than avoidance of warfarin, but being spared anticoagulation is valued by patients.8 The wider question is whether EARS will prove a better option overall than total root replacement. This we need to establish but wrapping the aorta with graft material9 (an approach largely abandoned) cannot be equated with EARS precisely modelled to intimately follow the contours of the aorta.3