Coronary arterial origins in transposition of the great arteries: Factors which affect outcome. A morphological and clinical study

Introduction- Transfer of the coronary arteries is crucial during the arterial switch operation for transposition (TGA) but little attention has been paid to the position of their orifices relative to the valvar sinuses. The aim of this study was to determine significant factors affecting surgical transfer. Design- Morphological and clinical study. Patients and Methods- 277 patients with TGA were studied. One group comprised 88 autopsy specimens (17 weeks gestation to 17 years), and the other comprised 189 children undergoing surgery in infancy. The coronary orifices were inspected visually or with echocardiography to determine position relative to the depth of the aortic sinuses (vertical origin), the commissures between the valvar leaflets (radial origin), and their angle of exit from the aortic wall (angle of origin). This data was compared with the surgical results. Results- Autopsied hearts: The vertical origin of each coronary artery was at or above the sinutubular junction in 20%. The radial origin was paracommissural in 3%, and the angle of origin was tangential in 7%. Those with high take-off and paracommissural origin were all intramural. Clinical cases: Children with high take-off (2%), paracommissural (2%) or tangential origin (3%) had an increased mortality and morbidity at surgery. Mortality from ischaemia for those with intramural coronary was 4/7 compared with 11/169 in those without (p<0.05). Overall, 20% had abnormal origins of the coronary arteries. Conclusions- Abnormal coronary artery origins are frequently found in TGA and are associated with increased surgical complications. However they may be recognised preoperatively by echocardiography and this may help reduce mortality during the arterial switch procedure.