Measurements of the descending aorta in infants and children: comparison with other aortic dimensions.

In paediatric cardiovascular surgery, knowledge of internal diameters along the first part of the aorta is essential. This paper presents reference data on the internal diameters of aortic ostium, ascending aorta, aortic isthmus and descending aorta, 1 cm distal to the ductus arteriosus. Measurements were made with the aid of calibrated probes in 126 post mortem specimens of normal hearts with great vessels. The age range was from 25 weeks of gestation up to 10 years after birth. The data revealed linear correlations between the internal diameters of the different parts of the aortic arch and body length. At variance with the literature, we found that, with few exceptions, the internal diameter of the ascending aorta was greater than that of the descending aorta.