Transposition of the Great Arteries Flashcards
What are diagnostic studies of TGA
CXR–show an egg shaped cardiac configuration, narrow mediastinum, and increased pulmonary markings with cardiomegaly
Fetal ultrasound—common antenatal diagnosis of TGA
Echocardiographic views: posterior great vessel that dives into right and left pulmonary arteries and arises from the left ventricle in assoication with an anterior aorta arising from a right ventricle. Can see shunts, position of coronary arteries, anatomy of av valves, degree of pulmonary stenosis,
Cardiac cath not required unless poor shunting or further classification needed
What is epidemiology, incidence, and clinical symptoms of TGA
10% of all infants with congenital heart disease
Ventriculoarterial discordance—the aorta arises from the right ventricle and the pulmonary artery from the left ventricle. Aorta is anterior and to the right of the pulmonary artery.
90% of children withe D-TGA with intact septum will die by 1 year of age. Most common PDA is the shunt.
most common clinical finding is cyanosis P02 of 25 to 50mmHg.
Preoperative medical management
Prostaglandin E1 usually administered to maintain ductal patency, to increase pulmonary blood flow, and to improve stabilization of patients before early operative repair.
adequate volume–avoid dehydration
Consider–Rashkind Balloon atrial septostomy for pts with persistent acidemia or hypoxemia
performed in either the ICU with echo or cath lab
Surgical Management options—Palliative operations
Initial procedure was creation of an ASD–mostly abandoned now
Pulmonary artery banding–maybe performed until operative repair at 3 to 6 months of age. Rare because most undergo neonatal repair.
Describe Atrial repair techqniques
Initial atrial switch by Senning in 1959— Pulmonary and systemic venous return is rerouted by incising and realigning the atrial septum over the pulmonary veins and using the free right atrial wall to create a pulmonary venous baffle.
Mustard procedure-1964—excising the atrial septum and creating a large interatrial baffle of pericardium to redirect pulmonary and systemic venous blood. This repair resulted in larger atrial size. Creation of a virtual common atrium is necessary with resection of the atrial septum
Outcomes from atrial procedures
Usually they did these procedures at age 3 to 8 months after a ballon septostomy
operative mortality ranged 2 to 10%. Long-term survival 88% at 10 years, 82% at 20 years, and 77% at 25 years.
Late systemic (right) ventricular dysfunction occurs in 5 to 25% Late arrhythmias are common
Describe the arterial switch/Jatene procedure
Arterial switch–1975–dividing the aorta and pulmonary artery, excising the origin of the coronary arteries with a button for aortic wall, repositioning the coronary arteries to the posterior great vessel (pulmonary artery) and reconstructing each ventricular outflow to the appropriate distal vessel.
Lecompte maneuver..the pulmonary artery bifurcation is brought anterior to the aorta
Initial mortality was 60%,however now it’s 4% in early periooperative care.
Outcomes of arterial switch procedure
long term survival appears improved.
Cardiac rhythm abnormalities are are (90% are in NSR)
left ventricular function is generally normal
late coronary problems appear rare but do occur.
Aortic root dilation occurs but surgery on the neo-aortic root is rare.
What is natural history of TGA
“About 50% of patients die within the first month without intervention. If needed, balloon atrial septostomy creates an interatrial openin”
Excerpt From: Carlos M. Mery & Joseph W. Turek. “TSRA Review of Cardiothoracic Surgery.” Feedbooks, 2011. iBooks.
This material may be protected by copyright.
What is a side effect of PGE infusion
“IV PGE1 infusion increases systemic-pulmonary shunting; intubation is often necessary due to prostaglandin-induced apnea.”
Excerpt From: Carlos M. Mery & Joseph W. Turek. “TSRA Review of Cardiothoracic Surgery.” Feedbooks, 2011. iBooks.
This material may be protected by copyright.
What are long term outcomes of TGA
“Ten-year survival after the arterial switch operation is 80%. Most patients achieve good exercise tolerance. Neopulmonary stenosis with RVOT obstruction is the most common indication for reintervention. Balloon dilation and/or stenting have been employed to correct the stenosis. In addition, neo-aortic root dilatation can be seen and is sometimes associated with AI.”
Excerpt From: Carlos M. Mery & Joseph W. Turek. “TSRA Review of Cardiothoracic Surgery.” Feedbooks, 2011. iBooks.
This material may be protected by copyright.
What is Rastelli procedure
“Those with TGA, pulmonary stenosis, and VSD undergo the Rastelli procedure. A patch is used to close the VSD and to direct the blood in the LV to the aorta. The pulmonary valve is surgically closed, and an artificial conduit and valve are constructed from the pulmonary bifurcation to the RV. Ten-year survival is 60%.”
Excerpt From: Carlos M. Mery & Joseph W. Turek. “TSRA Review of Cardiothoracic Surgery.” Feedbooks, 2011. iBooks.
This material may be protected by copyright.
