[The diameter of the descending thoracic aorta in patients with Fallot's tetralogy (angiographic study)].

The diameter of the descending thoracic aorta was measured at the level of the diaphragm on angiograms in 91 patients with Fallot's tetralogy. The existence of an exponential dependence of the diameter on the body surface area of patients as well as of healthy individuals was shown. The course of the regression curve in patients with Fallot's tetralogy repeated exactly the course of that in healthy individuals, but the former ran 0.5 mm higher. Thus, to determine the diameter of the descending thoracic aorta in patients with Fallot's tetralogy one may use the nomogram of the dependence of this diameter on the body surface area of healthy individuals or an equation suggested by the authors. It is practically impossible to locate the descending thoracic aorta by means of echography, whereas the size of its diameter is included in equations for calculating the important hemodynamic parameters. The data obtained by the authors allow wider use of noninvasive methods for the diagnosis (echo-morphometry) and prognostication of the results of radical correction of Fallot's tetralogy in a concrete patient.