Andersons pediatric cardiology 992

Incidence and results of reoperations following the Senning operation: 27 years of follow-up in 314 patients at a single center.. Arterial Switch Procedure Long-term survival following

FIG 37.25 Freedom from reoperation for failure of the systemic ventricle

(A) and complications related to the baffle (B) for patients after a Senning

operation (From Horer J, Karl E, Theodoratou G, et al Incidence and

results of reoperations following the Senning operation: 27 years of follow-up in 314 patients at a single center Eur J Cardiothorac Surg.

2008;33:1061–1068.)

Arterial Switch Procedure

Long-term survival following arterial switch procedure is excellent In one study, among perioperative survivors, the 25-year survival rate was 97%.101 Growth tends to be restricted in the early postoperative period, but this is followed by an acceleration so that the majority of children will have caught up with their

unaffected peers by 2 years of age.102 The majority of children and adolescents experience good overall health and quality of life that is not significantly

different from their peers Late mortality is rare, and the great majority of

patients will be without arrhythmia or symptoms of heart failure.103 In the first two postoperative decades, patients who underwent the arterial switch procedure had a decreased risk for heart failure and sudden death compared with those who underwent Mustard and Senning operations.104 In a study of young adults (>18 years), there were no clinically significant cardiac lesions and no need for

reintervention in 77% of patients.105 However, a significant number (82%) did have reduced exercise capacity Adults generally report a satisfactory health-related quality of life overall, although some will have psychological or

cognitive difficulties.106

A scientific statement by the American Heart Association in 2012 strongly

recommended that children with congenital heart disease, particularly those with cyanotic disease requiring neonatal cardiac surgery, be closely examined

throughout childhood for signs of developmental delay.107 Referral for formal behavioral or developmental testing should be made, with early intervention for those deemed to be at risk In patients with transposition, Andropoulos and colleagues found that one-third of infants had brain injury on preoperative brain magnetic resonance imaging and 43% had new injury postoperatively Although mean neurodevelopmental testing scores at 12 months were within normal

population ranges, a number of modifiable risk factors were associated with lower scores These included a lower preoperative and intraoperative cerebral oxygen saturation, the presence of cerebral injury on preoperative magnetic resonance imaging, the total bypass time, and the amount of midazolam used in the perioperative period.49 Throughout childhood, deficits have been found in speech and language, memory, visuospatial skills, attention, and executive

function.43 In a study of 16-year-olds after the arterial switch operation, scores

on formal developmental testing tended to be lower than peers, with a majority (65%) having received remedial academic or behavioral services.108

Fate of the Coronary Arteries

Coronary arterial obstruction is the most common cause of morbidity and

mortality after arterial switch, especially in the first 3 months following

surgery.43 In a review of late outcomes for more than 1000 patients after the arterial switch operation, coronary arterial problems were reported in almost 10%, and these problems contributed to nearly one-third of late deaths.109 It is concerning that obstruction is subclinical in a majority of patients There are a number of potential mechanisms for late problems after coronary arterial

translocation, which include anatomic distortion, extrinsic compression,

stretching, and intimal proliferation There is an expanding list of diagnostic modalities available for investigation of the coronary arteries Clinical history, electrocardiography, and echocardiography are insufficiently sensitive, although the addition of speckle tracking to conventional echocardiography may improve sensitivity in relation to clinical events.110 Coronary angiography remains the gold standard investigational technique, although this can be technically

challenging after arterial reimplantation Alternative investigational modalities include assessment of myocardial perfusion with technetium and thallium-201111 and positive emission tomography.112 These techniques have demonstrated that coronary arterial reserve may be decreased after the arterial switch, even in the absence of ischemic symptoms This concern is borne out by a study that

confirmed coronary arterial occlusion or stenosis in nearly 8% of children at a median of 7 years after surgery Importantly, the majority of these patients were asymptomatic.113 Another study reported coronary arterial lesions requiring intervention in 5% of a cohort of 755 patients.114

Multislice computed tomography has excellent spatial resolution, offering a noninvasive alternative to cardiac catheterisation.115 Progress is being made in reducing exposure to ionizing radiation.116 Magnetic resonance imaging,

although lacking the sensitivity of computed tomography, can detect ostial

obstruction with the added benefit of assessing left ventricular function and identifying the presence of myocardial scarring117 (Fig 37.26) Intravascular ultrasound can specifically examine the lumen and intima of the coronary

arteries.118 The exact implications of many of these findings are currently

uncertain, but they reinforce the need for careful follow-up and regular

reassessment Exercise testing, including stress imaging with echocardiography

or magnetic resonance, may reveal coronary insufficiency not evident at rest It

is unclear at this time whether the 25-year follow-up currently available will reflect similar findings over time or coronary abnormalities will worsen as

patients enter the age of acquired coronary heart disease