Mechanics of Selective Coronary Artery Catheterization via Femoral Approach

At the University of Minnesota Hospitals and the University of Virginia Hospital, selective coronary arteriography is performed by radiologists. The technic originally described by Sones (1) has been modified by introducing specially preformed catheters percutaneously into the subclavian, axillary, or femoral artery. Catheterization through the femoral artery appears to be the most advantageous, and a large experience has been accumulated with this method. The success of the procedure seems to depend largely on exact knowledge of the anatomy and adaptation of the catheter configuration to anatomical variations. The purpose of this communication is to help the novice by describing in detail such important factors in percutaneous transfemoral selective coronary arteriography as the anatomy of the aortic root, catheter materials and shapes, and technic of catheterization. Anatomy of the Aortic Root The aortic root is composed of the three bulbous aortic sinuses and the tubular ascending aorta (Fig. 1, a). At the junction of the bulbous portion and the tubular aorta, a circumferential thickening of the aortic wall exists, the socalled sinotubular ridge (P. Stanger and E. Edwards, unpublished data). The sinotubular ridge is an important landmark for selective coronary arteriography. Below it lie the sinuses of Valsalva, each of which is bordered largely by the aortic wall and to a lesser degree by the aortic cusp. The superior border of each aortic sinus is represented by an imaginary plane extending from the sinotubular ridge to the free margin of the aortic cusp. The free margin of each cusp is considerably higher at its commissural attachment than at its central portion. This anatomic feature is of particular importance in selective coronary arteriography since it permits a catheter to lie against the aortic wall of a sinus, traverse the cusp, and enter a coronary ostium on the opposite side. The line where the three cusps are in contact during diastole is referred to as the line of common closure. Contrary to common belief, the aortic sinuses are not of equal size. The noncoronary sinus (also referred to as the posterior sinus) is usually slightly larger than either the right or the left sinus. This discrepancy in size is particularly pronounced in senile ectasia and cystic medial necrosis (Fig. 1, b). The nomenclature of the sinuses is somewhat misleading. The in situ position of the aortic root is such that the socalled right sinus lies anteriorly, the left sinus posteriorly and to the left, and the posterior sinus posteriorly and to the right. The measured angle between the coronary arteries, which do not arise from exactly opposite sides of the aortic root, is only 100 to 140°, with a mean angle of 125° (Fig. 1, b). Usually the arteries arise fairly high within the sinus of Valsalva but below the sinotubular ridge. Although some variation occurs, each coronary ostium usually lies approximately midway between the commissural attachments of the corresponding cusp (Fig. 1, b). There is a slight funneling of the coronary ostium, which facilitates selective catheterization of the ostium (Fig. 1, c).