**9. Prognosis of TGA**

With the introduction of palliation followed by cardiac surgical procedures, the outcome of TGA has changed from a universally fatal disease to a long-term survival rate of over 90% [20]. Patients who undergo ASO have the best long-term survival and the lowest morbidity, and the best functional outcome compared to other surgical procedures. ASO is reported to have a > 95 percent survival at 15 to 25 years post-discharge, whereas survival in the Mustard atrial switch procedure is approximately 80 percent at 20 years and 75 percent at 25 years. [25] In the Rastelli procedure, 10-year survival rates are reported to be 80 to 94 percent [22]. Perioperative mortality is greater in patients with complex DTGA compared to those with simple DTGA. Progressive congestive heart failure and sudden death are the commonest causes of death. The clinical risk factors for mortality in TGA are prematurity, low birth weight, single coronary artery, aortic arch obstruction, and RV hypoplasia. Ninety-three percent of the ASO recipients are reported to be free from long-term cardiovascular complications, such as arrhythmia, cerebrovascular accident, heart failure-related hospitalization. Their cardiorespiratory exercise capability is at 91 percent of normal, while those who undergo atrial switch procedures 75 percent [26]. VSD repair, residual right-sided obstructive lesions, and decreased left ventricular function are the risk factors for poor exercise performance. Those who undergo Mustard or Senning operations are more likely to suffer from arrhythmia and right heart failure.

Neurodevelopmental impairment is common in babies after ASO [27–33]. Surgery at postnatal age > 2 weeks and the presence of VSD are documented to be associated with reduced perioperative brain growth and poor language performance scores at 18 months of age, respectively [15]. In one study, at 16 years of age, 65 percent of the ASO recipients required special education, occupational therapy,

**161**

**11. Conclusion**

hood is essential for the best outcomes.

*Transposition of Great Arteries*

*DOI: http://dx.doi.org/10.5772/intechopen.99205*

**10. Long term outcomes in adult survivors**

are the reported complications.

psychotherapy, and counseling; and about 20 percent suffered from attention deficit hyperactivity disorder and poor global psychosocial function scores [28]. The occurrence of seizures in the postoperative period is independently associated with lower neuropsychological scores. In another prospective study performed on 45 children with DTGA, the neurodevelopmental testing at age four to six years revealed the scores to be normal for cognition, language, and verbal working memory but lower for inhibition control, cognitive flexibility, social cognition, and executive function, when compared with controls [29, 30]. Neurodevelopmental outcomes are modified by the timing of diagnosis (prenatal versus postnatal), the severity of hypoxemia in the newborn period, the timing of surgery, associated cardiac defects, perioperative complications, necrotizing enterocolitis, and the need for extracorporeal membrane oxygenation. Brain MRI may be abnormal in 20–50% of cases who undergo surgery and demonstrate focal ischemic changes, white matter changes, volume loss, and periventricular leukomalacia [32, 33].

In the adult survivors of DTGA who undergo atrial switch procedure, RV failure

and TR are common as the morphological RV functionally supports the highpressure systemic circulation instead of the physiological low-pressure pulmonary circulation as it is supposed to [34]. More common long term complications are cardiac arrhythmias, which can result in sudden death due to atrial flutter. In the longer living survivors, sinus node dysfunction with the eventual need for pacemaker placement has been noted. In the adult survivors of ASO recipients, pulmonary arterial stenosis and distortion, neoaortic root dilatation, and aortic regurgitation

In the patients with LTGA, the congenitally corrected transposition, the systemic high-pressure circulation is supported by the morphological RV and a weak tricuspid valve. In these patients, TR is common which progressively worsens with age, eventually leading to RV failure. Additional surgical interventions may be required if RV dilatation or dysfunction appear. Almost 90% of cases of LTGA are associated with other cardiac defects, such as VSD (70–80%), PA (30–60%), mitral valve anomalies (straddling valve, additional cusps, dysplasia, 55%), and TR (90%). Rhythm disorders, like heart block or atrial arrhythmias, are common in them. Some of these patients may eventually require cardiac transplantation. Appropriate followup with periodic hemodynamic and functional assessment is an integral part of these

TGA is a complex congenital cyanotic cardiac anomaly characterized by ventriculoarterial or ventriculoatrial discordance. DTGA is the commonest cyanotic heart disease occurring during the first week of life. Advancements in early diagnostic measures, medical management, and surgical procedures have increased this former universally fatal disease's survival rate to over 90%. The post-surgical course is complicated by cardiac anatomic, hemodynamic, and rhythm disorders, which may require meticulous follow-up and additional surgical interventions, including cardiac transplants in some cases with LGTA. Long term outcome may be associated with normal to mild neurodevelopmental disabilities depending upon the type, complexity, and course of the disease. Expert follow-up of the patients into adult-

patients' subsequent specialized management for best outcomes [35].

#### *Transposition of Great Arteries DOI: http://dx.doi.org/10.5772/intechopen.99205*

*Congenital Anomalies in Newborn Infants - Clinical and Etiopathological Perspectives*

more postoperative complications.

**8.3 Complications of surgery**

**9. Prognosis of TGA**

from arrhythmia and right heart failure.

Palliation may be an option in some cases.

LVOO. In this procedure, the LV outflow tract obstruction is baffled through the VSD, thus closing it, and the oxygenated blood from the left ventricle is directed into the aorta. A valved conduit is placed between RV and PA, and the deoxygenated blood from the right ventricle enters the PA via the conduit. The Rastelli procedure with a perioperative mortality of <5 percent generally provides better and more durable relief of LVOT obstruction than ASO but has

d.TGA with VSD and pulmonary arterial vascular disease: This is a rare type in which surgery may not be beneficial as PA hypertension is progressive.

Complications may occur in 5 to 25 percent of patients who undergo ASO; the commonest one that will need reintervention is pulmonary artery stenosis [22–26]. If the right ventricular pressure becomes close to systemic levels or if the lung perfusion scan is abnormal catheter-based dilation and stent placement may be performed. Other less common complications include coronary artery insufficiency, neo-aortic root dilation, and neo-aortic regurgitation. With the Rastelli procedure, complications such as conduit stenosis needing replacement, atrial and ventricular arrhythmias, and right and left ventricular failure are reported. Complications of the atrial switch include right ventricular failure, arrhythmias, and baffle-related sequelae [20, 23, 24].

With the introduction of palliation followed by cardiac surgical procedures, the outcome of TGA has changed from a universally fatal disease to a long-term survival rate of over 90% [20]. Patients who undergo ASO have the best long-term survival and the lowest morbidity, and the best functional outcome compared to other surgical procedures. ASO is reported to have a > 95 percent survival at 15 to 25 years post-discharge, whereas survival in the Mustard atrial switch procedure is approximately 80 percent at 20 years and 75 percent at 25 years. [25] In the Rastelli procedure, 10-year survival rates are reported to be 80 to 94 percent [22]. Perioperative mortality is greater in patients with complex DTGA compared to those with simple DTGA. Progressive congestive heart failure and sudden death are the commonest causes of death. The clinical risk factors for mortality in TGA are prematurity, low birth weight, single coronary artery, aortic arch obstruction, and RV hypoplasia. Ninety-three percent of the ASO recipients are reported to be free from long-term cardiovascular complications, such as arrhythmia, cerebrovascular accident, heart failure-related hospitalization. Their cardiorespiratory exercise capability is at 91 percent of normal, while those who undergo atrial switch procedures 75 percent [26]. VSD repair, residual right-sided obstructive lesions, and decreased left ventricular function are the risk factors for poor exercise performance. Those who undergo Mustard or Senning operations are more likely to suffer

Neurodevelopmental impairment is common in babies after ASO [27–33]. Surgery at postnatal age > 2 weeks and the presence of VSD are documented to be associated with reduced perioperative brain growth and poor language performance

scores at 18 months of age, respectively [15]. In one study, at 16 years of age, 65 percent of the ASO recipients required special education, occupational therapy,

**160**

psychotherapy, and counseling; and about 20 percent suffered from attention deficit hyperactivity disorder and poor global psychosocial function scores [28]. The occurrence of seizures in the postoperative period is independently associated with lower neuropsychological scores. In another prospective study performed on 45 children with DTGA, the neurodevelopmental testing at age four to six years revealed the scores to be normal for cognition, language, and verbal working memory but lower for inhibition control, cognitive flexibility, social cognition, and executive function, when compared with controls [29, 30]. Neurodevelopmental outcomes are modified by the timing of diagnosis (prenatal versus postnatal), the severity of hypoxemia in the newborn period, the timing of surgery, associated cardiac defects, perioperative complications, necrotizing enterocolitis, and the need for extracorporeal membrane oxygenation. Brain MRI may be abnormal in 20–50% of cases who undergo surgery and demonstrate focal ischemic changes, white matter changes, volume loss, and periventricular leukomalacia [32, 33].
