Malpositioned great vessels are defined by an abnormal ventriculoarterial junction combined with interventricular communication. They are due to the defective development or resorption of the subaortic and pulmonary conus. It concerns a great variety of anatomic localizations, hemodynamics mainly depend on whether the malformation is associated with a pulmonary stenosis or a hypoplastic coarcted aorta. Resulting hypoxemia varies with the volume of pulmonary flow and the relative position of the vessels with the ventricles and the interventricular communication. Corrective surgery bringing the left ventricle towards the aorta and right ventricle to pulmonary artery without using prosthetic tubes is usually possible when the interventricular communication is located under the vessels. Surgery may simply consist of tunneling the left ventricle toward the aorta or tunneling the left ventricle toward the pulmonary artery and then switching the arteries and transferring the coronaries or still yet tunneling the left ventricle toward the aorta and repositioning the pulmonary artery (with no valve) on the right ventricle. When one of the three surgical procedures is possible, operatory risks are low and results are satisfactory in the middle term and probably in the long term.
Last update: November 2004