Metric characterization of the aortic arch of early mouse fetuses and of a fetus featuring a double lumen aortic arch malformation

This study aimed at providing an objective metric characterization of the aortic arch of a mouse fetus featuring a double lumen aortic arch malformation. As a side effect it provides reference data defining the length and the diameters of the aortic arch segments of normally developed mouse fetuses at developmental stage 22 according to Theiler (TS22). We analyzed a total of 22 TS22 mouse fetuses of the Him:OF1 strain. We produced high-resolution three-dimensional (3D) computer models and measured the diameters and cross sectional areas of the aortic arch segments and of the ascending and descending aorta. In addition, we defined 3D skeletons of the arteries and measured the length of the aortic arch segments. We provide statistics on the measurements obtained from the normally developed TS22 fetuses and detailed characterizations of the double lumen aortic arch. Our data suggest that: firstly, in Him:OF1 fetuses of TS22, the formation of the aortic arch is not yet finished. The left subclavian artery still receives a significant amount of blood from the right ventricle. Secondly, persistence of the 5th pharyngeal arch artery does not affect remodeling of the arteries distal to the junction of 5th pharyngeal arch artery and dorsal aorta. Thirdly, hemodynamic forces define the dimensions of the aortic arch between the left common carotid and the left subclavian artery. Fourthly, the blood volume streaming through the 4th pharyngeal arch artery influences its enlargement between TS20 and TS22.