Correspondence (reply): In Reply

It would certainly make perfect sense to consider a patient’s body height when assessing aortic diameters (1), as suggested by Kuklinski. Simple and practical indexing to the body surface area helps individualized assessment of aortic dilatation. For example, in patients of short stature the risk of complications may be underestimated on the basis of considering the absolute diameter only. Since only few clinical data for indexing exist, this has thus far not been included in any guidelines. Defining normal values and threshold values need to be defined by means of clinical studies. We gave pointers for a possible practical approach that is based on the currently available evidence (1).

The lacking standardization of how the aortic diameter is measured, as raised by Kuklinski, is an unsolved problem since several existing guidelines provide different recommendations (2, 3). The current US guidelines recommend measuring the internal diameter by using echocardiography and the external diameter by using CT/MRI scanning (2). Echocardiography is restricted by the limited visibility of the ascending aorta and the variability of the diameter with the imaging plane. CR and MRI investigations allow for better reproducibility, but it has to be borne in mind that the diameter varies between systole and diastole. In younger patients with repeated investigations, MRI is the investigation of choice because of the lack of exposure to radiation (1).

The prognosis of aneurysms of the ascending aorta is determined not only by the diameter but, crucially, also by other risk factors, progression, and etiology (1). We agree with Schmidtke and von Kodolitsch that the care of patients with congenital disorders of the connective tissues is an important topic. In spite of substantial increase to what is known about the subject over the past decade, many details of the genotype and phenotype changes remain unknown. Currently we can therefore make only tentative recommendations for managing patients with congenital connective tissue disorders. Screening of the ascending aorta is recommended for all first-degree relatives of patients with congenital aortic disorders—that is, connective tissue disorders, bicuspid aortic valve, etc (2). Genetic diagnosis is indicated if it is of therapeutic relevance for the patient—for example, the intensity of monitoring, the timing of potential aortic replacement, or if they are planning to have children.

In conclusion, further studies of aneurysms of the ascending aorta are urgently needed.