Background: Translocation of the coronary artery to the neoaorta is essential in the arterial switch operation. The goal of this study is to investigate (1) the frequency of commissural malalignment in complete transposition of the great arteries, (2) the usefulness of echocardiography in diagnosis of commissural malalignment, and (3) the impact of commissural malalignment on surgery.
Methods: We retrospectively reviewed the medical records of 28 patients with complete transposition of the great arteries who underwent an arterial switch operation from February 2000 to August 2001.
Results: Commissural malalignment was expected preoperatively in 11 patients by echocardiography and was confirmed in 13 patients intraoperatively. Four patterns of commissural malalignment were present: (1) sinus-facing of the pulmonary valve, (2) sinus-facing of the aortic valve, (3) sinus-facing of both valves, and (4) bicuspid pulmonary valve (functionally sinus-facing). Two patterns of severity were present: major and minor. To avoid torsion and stretching of the coronary arteries during surgery, various methods were needed: more extensive dissection of the coronary artery, trap door incision, supracommissural or juxtacommissural transfer, both coronary transfer to the same sinus, tube reconstruction of the coronary artery, and neoaorta dextrorotation anastomosis. One patient who had severe commissural malalignment died during the operation, and the cause of death was probably stretching or torsion of the coronary artery.
Conclusions: The recognition of malalignment of the facing sinus in transposition of the great arteries can be detected preoperatively by echocardiography. The surgical procedure of the arterial switch operation is influenced by the presence of commissural malalignment. Preoperative awareness of commissural malalignment seems to be helpful for surgeons to predict the need for an alternative operational procedure.