Percutaneous Aortic Valve ReplacementThe Anatomy of Aortic Root Structures and Postmortem Aortic Valve Stent Implantation
Background: Previous studies have suggested that the close proximity of the coronary orifice to the aortic valve leaflets made percutaneous and transapical aortic valve implantation a major challenge such as coronary flow impairment. In this study, the aortic root structures were observed and measured in human cadavers. Material and Methods: We assessed the diameter of the distal ascending aorta, the proximal ascending aorta, the STJ, the aortic annulus, the coronary ostia, and the distance of the annulus to the coronary ostia, the coronary ostia to the STJ level, each ostium to its bilateral commissure of the aortic leaflet, the height of the aortic leaflets, and the aortic annulus to the STJ level. Meanwhile, the malformation, location, number, and shape of the coronary artery orifices and the presence of accessory orifices were observed and recorded. During the study, the relation of the coronary ostia, the aortic leaflets, and the valved stent were also investigated through the post mortem aortic valved stent implantation. Results: The results demonstrated that most of the coronary ostia were located below the STJ level, only very few coronary ostia were at or above the same. The left coronary ostia cluster near to the central region of the sinus curvature, while the right coronary ostia tend to locate eccentrically, a lower position, and in the right side of the sinus. Most of the coronary ostia, which were located below the STJ, were covered by its corresponding aortic leaflets; while the ostia were rarely covered by the aortic leaflets if they lay at or above the STJ. The right coronary ostia were more frequently covered by its aortic leaflets than the left ones. Conclusion: To perform an orthotopic PAVR, resection of the native leaflets before implantation of the valved stent might be necessary and new stents have to be designed to prevent coverage of the coronary ostia by crimping the leaflets.