pediatrics
Transposition of the Great Arteries (TGA)
Treatment of TGA
Prostaglandin E1 (PGE1) infusion Sometimes balloon atrial septostomy Surgical repair Unless arterial oxygen saturation is only mildly decreased and the atrial communication is adequate, a PGE1 infusion may help by opening and maintaining patency of the ductus arteriosus; this infusion increases pulmonary blood flow, which may promote left-to-right atrial shunting, leading to improved systemic oxygenation. However, if the patent foramen ovale has a small opening, PGE1 may have the opposite effect because the increased blood return to the left atrium may close the flap of the foramen ovale, leading todecreasedmixing, along with elevation of left atrial pressure and pulmonary edema. Also, opening the ductus may decrease systemic blood flow. Thus, PGE1 must be used with caution, and patients must be monitored closely. Metabolic acidosis is treated withsodium bicarbonate. Pulmonary edema and respiratory failure may require mechanical ventilatory support. PGE1 infusion is usually helpful in D-TGA, but it can be harmful if the patent foramen ovale is small. For severely hypoxemic neonates who do not immediately respond to PGE1 or who have a very restrictive foramen ovale, cardiac catheterization and balloon atrial septostomy (Rashkind procedure) can immediately improve systemic arterial oxygen saturation. A balloon-tipped catheter is advanced into the left atrium through the patent foramen ovale. The balloon is inflated and abruptly withdrawn to the right atrium to enlarge the opening in the atrial septum. As an alternative to taking the neonate to the catheterization laboratory, the septostomy procedure can be done at the bedside under echocardiographic guidance. Definitive repair of d-TGA is the arterial switch (Jatene) operation, typically done during the first week of life. The proximal portions of the great arteries are transected, the coronary arteries are transplanted to the native pulmonary root, which will become the neoaortic root, the aorta is connected to the left ventricle, and the pulmonary artery is connected to the right ventricle. Survival rate after surgery is>95%. An associated VSD should be closed at the time of primary repair unless it is small and hemodynamically insignificant. Native pulmonic stenosis is problematic unless it is mild because pulmonic stenosis will effectively become aortic stenosis after the arterial switch procedure. If pulmonic stenosis is moderate or severe, other surgical options may need to be considered. Because of the technical difficulties of transplanting the coronary arteries in neonates and infants, the arterial switch procedure could not be done before the early 1980s ( Treatment references ). Prior to that era, patients with D-TGA were treated with an "atrial switch" operation, referred to as either a Mustard or Senning procedure. This operation reconstructed the atrial septum and placed an intra-atrial baffle to divert the superior vena cava and inferior vena cava return to the left ventricle and the pulmonary venous return to the right ventricle. There are many adults with D-TGA born before 1980 who had this repair ( Prevention is recommended preoperatively but is required only for the first 6 months after repair unless there is a residual defect adjacent to a surgical patch or prosthetic material. 1.Castaneda AR, Norwood WI, Jonas RA, et al: Transposition of the great arteries and intact ventricular septum: Anatomical repair in the neonate.Ann Thorac Surg38:438–443, 1984. doi: 10.1016/s0003-4975(10)64181-1 2.Kempny A, Dimopoulos K, Uebing A, et al: Outcome of cardiac surgery in patients with congenital heart disease in England between 1997 and 2015.PLoS One12(6):e0178963, 2017. doi:10.1371/journal.pone.01789631 3.Meadows AK: Transposition of the Great Arteries after Mustard/Senning Repair. Adult Congenital Heart Association June 15, 2016. Accessed November 3, 2011. https://www.achaheart.org/your-heart/health-information/transposition-of-the-great-arteries-after-mustardsenning-repair/ 