Comprehensive macroscopic living anatomy of the swine heart: comparative visual approach with virtual dissection

Swine is one of the major large animal species used in translational research. Extensive knowledge has been accumulated on the normal anatomy of the swine heart, highlighting its similarities with the human heart, including its size and coronary arterial system. However, when these hearts are compared three-dimensionally as they lie on each thorax without distortion, remarkable differences are recognized beyond already known similarities. Those differences include, but are not limited to, the cardiac axis, aortic axis, aortic arch plane, aortic arch/pulmonary trunk relationship, atrial appendages extent, pulmonary arteries/veins/trachea/bronchi relationship, left azygos vein drainage, coronary arterial orifices relationship, fossa ovalis/aortic root relationship, and ventricular trabeculations features. In addition to conventional and rough recognition of similarities between the swine and human hearts, detailed knowledge of differences in the living anatomy of the swine and human hearts is especially fundamental for conducting effective in vivo experiments, including fluoroscopic procedures and survival studies with surgical intervention. Also, this knowledge is useful for discussing the feasibility and limitations of applying the insights obtained from the swine heart study to the human heart. Thus, we herein demonstrate comprehensive macroscopic living anatomy of the swine heart compared with that of the human heart using cardiac computed tomographic datasets obtained from live swine, as well as datasets from recovered swine hearts after pressure-perfusion and fixation to maintain their physiological, non-distorted anatomy.