Medical Care
Initial evaluation and treatment are usually performed in an outpatient setting. Treatment varies depending on the anatomy of the lesion. Direct medical treatment of infants with double outlet right ventricle (DORV) at control of congestive heart failure (CHF). Hospitalize children who present with severe heart failure and treat them with fluid restriction and reduction of physical stress. Monitor children to ensure adequate weight gain because CHF can decrease oral intake and increase caloric expenditure. Provide inpatient care if congestive heart failure (CHF) is severe. Treat patients initially with fluid restriction and alleviation of temperature and physical stress. Sedation may be required with opioids. Other therapies include the following:
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Oxygen therapy may be required if pulmonary edema is present.
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Use oxygen only to relieve hypoxemia because it is a pulmonary vasodilator and can exacerbate left-to-right shunt and CHF.
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Promptly initiate diuretic therapy with furosemide.
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Glycoside therapy with digoxin can be initiated in a maintenance dose if severe CHF is not present.
Systemic afterload reduction is important in treating infants with CHF. ACE inhibitors (ie, captopril, enalapril) are the most commonly used afterload-reduction agents. [11]
Transfer may be required for further diagnostic testing and medical/surgical treatment.
Surgical Care
In 1957, Kirkland reported the first surgical repair of double outlet right ventricle (DORV) using an intraventricular tunnel to establish left ventricular-aortic continuity via subaortic ventricular septal defect (VSD). Surgical repair usually requires cardiopulmonary bypass with moderate hypothermia. Many double outlet right ventricles have been repaired with a period of circulatory arrest.
Most transpositions are repaired using a biventricular approach with placement of an intraventricular baffle; this is more difficult without 2 well-developed ventricles or if the anatomy precludes a biventricular repair. [12] An alternative repair is a Fontan procedure, which deteriorates with time.
In general, procedures depend on the location of the VSD and the size of the left ventricle. A significant number of patients undergo palliative procedures prior to definitive repair, especially when the patients have borderline or hypoplastic left ventricles. These procedures include pulmonary artery banding, Blalock-Taussig shunt, coarctation repair, or a stage I Norwood procedure.
Observe and manage ventricular function for patients in immediate postoperative period. Arrhythmias may develop after repair and may require medical intervention.
After repair, children with DORV are often treated with systemic afterload reduction using ACE inhibitors for several months to assist in cardiac remodeling.
Double outlet right ventricle with subaortic VSD
Double outlet right ventricle with subaortic VSD is repaired by VSD closure to baffle the left ventricular outflow to the aorta. It is typically repaired in patients younger than 6 months to prevent pulmonary vascular disease. If severe pulmonary stenosis is present, the condition and repair are similar to those of tetralogy of Fallot. Pulmonary stenosis often occurs with hypoplasia of the pulmonary arteries and coronary artery anomalies, making repair more difficult. Historically, this condition often was treated with initial shunting and definitive repair in patients aged 4-5 years.
Double outlet right ventricle with subpulmonary VSD
Double outlet right ventricle with subpulmonary VSD can be repaired using the following 3 methods:
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The first procedure involves construction of a left ventricle–to–subpulmonary outflow tract tunnel with a subsequent arterial switch. This is the preferred method when the aorta is malposed anteriorly. Coronary artery transfer is similar to that in transposition of the great arteries.
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The second method consists of construction of a long intraventricular tunnel to establish continuity between the left ventricle and the aorta and between the right ventricle and pulmonary artery.
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The third method involves closure of the VSD with baffling of the left ventricular outflow to the pulmonary artery with a subsequent atrial baffle (eg, Senning procedure, Mustard procedure). This method is associated with high operative and late mortality rates.
Doubly committed or noncommitted VSD
Doubly committed or noncommitted VSDs often require a complex repair with a Fontan procedure and possibly reoperation for secondary subaortic stenosis. For example, a patient with double outlet right ventricle, complete atrioventricular septal defect (AVSD), and valvar pulmonary stenosis underwent repair involving patching the ventricular portion of the AVSD and translocating it into a subaortic position. A left ventricular–to–aortic tunnel was then created. Nine years after primary repair, the patient required right ventricle–to–pulmonary artery conduit replacement.
One case series studied 50 children with double outlet right ventricle and adequate left ventricular size. [13] Eleven patients in the study had double outlet right ventricle with transposition of the great vessels. Biventricular repair was performed in 48 of the children, and the overall mortality rate was 6%. Actual surgical mortality rate in patients with biventricular repair was 4.3%.
In contrast, surgical and overall morbidity and mortality rates increase with more complex types of double outlet right ventricle. Takeuchi et al recently reported a case series of 96 patients with double outlet right ventricle and heterotaxy syndrome and/or complete atrioventricular canal defect. [14] Only 8 patients had biventricular repair. Nine of the 17 neonatal patients survived. Of the 79 patients older than 30 days, 71 survived. The overall mortality rate was 17% in all patients.
Consultations
Refer patients with heart murmurs and physical findings suggestive of double outlet right ventricle to a pediatric cardiologist.
Consult a pediatric cardiac surgeon for possible repair following diagnosis of double outlet right ventricle.
Consult pediatric critical care personnel. Following surgical repair, postoperative care normally occurs in the pediatric ICU.
Involve a geneticist in the care of patients diagnosed with double outlet right ventricle who may have associated genetic syndromes, including velocardiofacial syndrome and DiGeorge syndrome. [15, 16]
Diet
Children with CHF due to double outlet right ventricle often require increased caloric intake supplemented by the addition of medium-chain triglyceride or carbohydrate preparations to conventional infant formulas.
Some children may require overnight, bolus, or continuous feeds by nasogastric tubes.
Activity
Activity is not limited for infants initially diagnosed with double outlet right ventricle, unless they have CHF. For patients with CHF, reduce physical stress until the heart failure can be controlled.
Advance the activity of patients in the postoperative period as tolerated, until a normal level of activity is achieved.
Complications
If patients undergo surgery for repair at an older age, they often develop ventricular dysfunction and elevation of pulmonary artery pressures.
Operative and postoperative complications depend on anatomy of lesion and type of repair. Note the following:
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Some patients develop restrictive ventricular septal defect (VSD) and require reoperation.
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In patients with subaortic and subpulmonary VSD, the VSD diameter can decrease by 20% in the immediate postoperative period. These patients can sometimes develop subaortic obstruction.
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Patients, especially those undergoing complex repair, can develop postoperative ventricular dysfunction associated with residual VSD, aortic insufficiency, atrioventricular valve insufficiency, and prolonged circulatory arrest at repair.
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Some patients are at risk for late postoperative arrhythmias and sudden death.
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Patients may develop persistent atrial tachycardia, complex ventricular ectopy, or syncope requiring electrophysiologic studies.
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Neonate with double outlet right ventricle. Chest radiograph shows a mildly enlarged heart with symmetrically slightly increased pulmonary vasculature.
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Double outlet right ventricle with subaortic ventricular septal defect. Arrow shows flow of oxygenated blood from left ventricle to aorta.
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Repair of double outlet right ventricle with subaortic ventricular septal defect.
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Double outlet right ventricle with subpulmonary ventricular septal defect (Taussig-Bing anomaly).
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Complex repair of double outlet right ventricle with subpulmonary ventricular septal defect.
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Double outlet right ventricle with doubly committed ventricular septal defect.
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Repair of double outlet right ventricle with doubly committed ventricular septal defect showing VSD patch and intraventricular baffle.
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Double outlet right ventricle with noncommitted ventricular septal defect.
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Repair of double outlet right ventricle with noncommitted ventricular septal defect using a long ventricular septal defect patch.
