[Interarterial and intramural coronary trajectoris: anatomic aspects and surgical implications].

Among the coronary trajectory anomalies found not only in congenital cardiopathies but also in otherwise normal hearts, the terms intramural and interarterial are still used in an ambiguous fashion too frequently. Study of the embryonic development of the coronaries allows a better understanding of the possibility of such a trajectory, (existence of the periarterial sheath). Certain anatomical factors favour the existence of an intramural coronary trajectory, the coronary always being tangential to the aorta in this case: paracommissural ostium, ostium situated too high, departure of the coronary at an acute angle, and ostium in the form of a slit. However, interarterial and intramural are not synonyms. In the case of a coronary trajectory tangential to the aorta, three anatomical and histological situations are possible: free trajectory, with the aorta and the coronary each having its own media and its own adventitia; adherent trajectory, with two separate media covered by a common adventitia: and true intramural trajectory, with fusion of the media without interposition of adventitia. These three situations have different surgical implications in the case of coronary reposition.