Coronary artery bypass grafting in children for atheromatous and non-atheromatous lesions

Abstract

Coronary artery involvement in children is an uncommon but well-recognized clinical entity. It is an important cause for sudden cardiac death in children. Diagnosis requires a high index of suspicion since it has serious consequences when missed. Presentation of coronary artery abnormality is very variable due to congenital as well as acquired aetiology. In this review, we have described the different causes that require coronary artery bypass grafting in children and their pathogenesis. The nuances of conduit selection, graft behaviour in children, patency rates and long-term outcomes in children undergoing coronary artery bypass have also been discussed.

Introduction

Coronary artery abnormality in children is an uncommon but a well-recognized clinical entity. Symptoms are often vague due to inability of children to articulate their problems accurately. There is also a low index of suspicion on part of the clinicians towards diagnosing coronary artery pathology in children. As a result, children with Kawasaki disease are often misdiagnosed as having an infectious pathology and sepsis, autoimmune disorders and malignancies [1]. Also, the symptoms are often labelled to be functional leading to a wrong treatment pathway, and in some cases, these children remain completely undiagnosed and untreated until quite late. Coronary artery abnormalities account for up to 1 in 100 causes of sudden cardiac death in children [2]. A clear understanding of the pathology can thus save lives and avoid unwarranted loss of myocardium in childhood. Coronary artery bypass grafting (CABG) is not uncommonly required in these children and the considerations are quite different from coronary artery disease in adults. Unlike adults, in children, stenotic lesions constitute only one indication for CABG. Congenital abnormalities involving the coronary arteries, through different pathophysiological mechanisms, constitute other indications for CABG in children. With improved diagnostic capabilities, these abnormalities are being picked up more commonly and the number of CABGs performed in children is on the rise. It is therefore important to understand the aetiopathogenesis, indications and pitfalls of CABG in these children.

Coronary artery abnormalities in children

There are a number of different congenital and acquired clinical situations that can cause coronary artery abnormalities in children necessitating CABG (Table 1).

Table 1.

Conditions where CABG is required in children

Congenital	Acquired
• Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA)	• Kawasaki disease
• Congenital ostial stenosis and atresia	• Familial hypercholestelorlaemia
• Anomalous origin of coronary arteries from aorta	• Iatrogenic causes: complications secondary to Arterial switch operation Ross procedure Tetralogy of Fallot
• Supravalvar aortic stenosis

The commonest cause for coronary artery pathology in childhood is Kawasaki disease. Familial hypercholesterolaemia (FH) is an important cause of coronary artery disease in children and in adolescence. Congenital coronary ostial stenosis and abnormal coronary artery origin is rare but an important cause. First reported paediatric coronary artery bypass grafting was for anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) [3]. Anomalous aortic origin of a coronary artery (AAOCA) from the inappropriate sinus of Valsalva is an important cause of sudden death, most commonly seen with interarterial anomalous left coronary artery (ALCA) and anomalous right coronary artery (ARCA) [4]. Supravalvar aortic stenosis has been reported frequently as another cause for impaired flow to the coronary arteries and in fact it has been suggested that every patient with supravalvar aortic stenosis should be considered at risk of myocardial ischaemia [5].

Iatrogenic causes of coronary artery surgery are seen predominantly after coronary transfer in arterial switch operation and the aortic reimplantation procedure for ALCAPA as well as injury to the left anterior descending (LAD) artery during the Ross procedure and repair of tetralogy of Fallot.

Pathogenesis, presentation and indications for CABG

Kawasaki disease

The aetiology of Kawasaki disease remains unknown. However, one of the proposed hypotheses is that it results due to exposure to an infectious agent that produces clinically apparent disease only in certain genetically predisposed individuals, most commonly Asians, and especially in the Japanese population [6]. Reports exist of the Kawasaki disease being triggered by Epstein-Barr virus infection [7]. Acute febrile illness, mucocutaneous rash and lymphadenopathy are the three most important features in the presentation of Kawasaki disease.

Kawasaki disease is basically a vasculitis with a special predilection for coronary arteries but can also affect other extra-parenchymal muscular arteries like the mesenteric, renal, femoral and axillary arteries [8].

In the context of coronary arteries, Kawasaki disease can have both acute and chronic presentations. It can present acutely as coronary artery aneurysms that may lead to rupture and death or can also present as obstructive coronary artery disease, which is a chronic sequela of the disease.

Mostly children below 5 years are affected, and the condition is more common in boys, with coronary artery abnormalities seen in approximately 15–25% of untreated cases [6, 9, 10]. Majority of the coronary aneurysms regress over a period of time. Aneurysms which are small, fusiform rather than saccular, peripherally located and in younger children (less than 1 year) usually regress [6]. Only those aneurysms which are > 8 mm in size do not regress and lead to the subsequent coronary stenosis at the site of exit and entry (or both) of the aneurysm. Moreover, they almost always contain thrombus that can embolize distally leading to myocardial ischaemia. Typical site of involvement is the left main coronary artery (LMCA), right main or proximal segment of the coronary artery. Those coronary aneurysms, which are distally located and < 8 mm in size, usually regress [11].

Kawasaki disease arteriopathy involves three pathological processes that include necrotizing arteritis, subacute/chronic vasculitis and luminal myofibroblastic proliferation (LMP). In the first phase, which lasts for about 2 weeks, there is a self-limiting, synchronized neutrophilic process that progressively destroys the arterial wall into the adventitia, causing aneurysms. Second phase, which begins in the first 2 weeks after the onset of fever and can continue for months to years, is associated with an asynchronous infiltration of lymphocytes, plasma cells and eosinophils with fewer macrophages and is closely linked to the third process of LMP. LMP is an active proliferative process that can cause progressive arterial stenosis in patients [11].

The most common indication for CABG in children is coronary ischaemia due to Kawasaki disease [12]. Decision to carry out CABG in Kawasaki disease should also take into consideration patient’s symptoms, age, ventricular function, myocardial viability and angiographic findings [13]. Generally the indications for coronary bypass graft procedures in children with Kawasaki disease include presence of reversible ischaemia on stress imaging tests with a viable myocardium (level of evidence C) [6]. Expert opinions suggest that CABG in children may be considered if there is severe occlusion of the main trunk of the LMCA (Fig. 1) or one major coronary artery, or severe occlusion of proximal LAD with poor collateral coronary circulation. It is also agreed upon that recurrent myocardial infarction (MI) is an indication for CABG in these children [14, 15].

Fig. 1.

Left main stem stenosis in Kawasaki disease

It has been shown that in patients who needed CABG, the only predictor for survival was the duration between acute Kawasaki disease and timing of CABG. Thus, a short interval between diagnosis of acute Kawasaki disease and CABG appears to carry a better prognosis in these patients [16]. Besides, presence of large thrombus in a giant aneurysm with or without occlusive coronary artery disease has also been taken as an indication for CABG by some authors [16].

Anomalous origin of coronary arteries from aorta

Coronary anomaly is the second most common cause of cardiac sudden death in young athletes [17]. AAOCA from the inappropriate sinus of Valsalva is an important cause of coronary artery issue in children. Although there are many different classifications and subtypes, most AAOCA subtypes are benign. However, the risk of sudden death is most commonly seen with interarterial ALCA and ARCA.

Overall the true prevalence of AAOCA in the general population remains unknown. Based on studies, where screening was carried out in presence of a clinical indication, the incidence reported ranges from 0.15 to 0.7%. The incidence of ALCA is rarer (0.03%) as compared with interarterial ARCA (0.23%) [4].

Clinical presentation varies widely, from being asymptomatic to sudden cardiac death. Other presentations include mild chest pain, palpitation and syncopal attacks. Heavy exercise can often unmask the symptoms.

Although anomalous right coronary arteries are incidentally found more frequently [18], sudden cardiac death (SCD) is most often associated in patients with anomalous left coronary arteries (6.3%) as opposed to 0.2% with anomalous right coronary artery [19]. Ischaemia is thought to be the cause of SCD in these patients.

The proposed mechanisms of ischaemia-induced SCD include acute angulation at the ostium of the coronary artery and kinking; an abnormal slitlike opening; mechanical compression of the anomalous artery as it courses between the aorta and pulmonary artery brought about during exertion; and vasospasm of the anomalous artery. Mechanical compression is brought about by the partial or near total compression of the anomalous artery due to diastolic expansion of the great arteries during heavy exercise.

While trans-thoracic echocardiography (TTE) is useful for intracardiac abnormalities and assessment of cardiac function, it lacks detailed characterization of AAOCA features and surrounding structures [20]. Considering the availability of non-invasive techniques to visualize coronary artery anatomy, trans-oesophageal echocardiography (TEE) is currently not a routine tool to image AAOCA. Coronary computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are the only tests used to image AAOCA and carry a class I recommendation [21].

AAOCA with a non-interarterial course has an excellent prognosis and management plans are based on clinical presentations. Revascularization is recommended for interarterial ALCA, regardless of ischaemia or symptoms. Revascularization is also recommended for ARCA patients with an interarterial course or intramural artery [21].

According to 2011 ACC/AHA Guideline for CABG [22] and 2008 ACC/AHA Guidelines for Management of Adults With Congenital Heart Disease (ACHD) [21], class I recommendation for CABG in AAOCA includes anomalous LMCA with an interarterial course, ischaemia due to coronary compression (when coursing between the great arteries or in intramural fashion) and interarterial ARCA and evidence of ischaemia.

Anomalous origin of the left coronary artery from the pulmonary artery

Anomalous origin of the left coronary artery from the pulmonary artery is an important cause of myocardial infarction, ventricular dysfunction and other complications including death. Establishment of a two-coronary artery system is recommended. ALCAPA is a completely separate entity and beyond the scope of discussion in this review.

Iatrogenic causes

CABG due to iatrogenic injury usually is indicated as a salvage or rescue procedure during arterial switch, Ross procedure and tetralogy of Fallot repair in children [23]. Approximately 7% cases of tetralogy of Fallot can have LAD crossing in front of the right ventricular outflow tract causing difficulty in placing transannular patch [24, 25] which is more likely to be injured in the presence of intramyocardial LAD or if there are adhesions as seen in reoperations.

Congenital ostial stenosis and atresia

This is an extremely rare condition and presentation is similar to the clinical signs and symptoms of ALCAPA.

In this condition, the proximal LMCA ends blindly. It receives retrograde blood through collaterals from the right coronary system [26]. Differentiation is often only possible on visualization of LMCA ostia and can often be associated with mitral insufficiency and supravalvar aortic stenosis [24, 25]. Presentation is variable with some presenting very early in childhood with symptoms of syncope, dyspnoea, sudden death, failure to thrive, infarction and ventricular tachycardia, while others get diagnosed only at an advanced age [27]. Thus, presentation and diagnosis primarily influence treatment. However, the condition is often mistaken for ALCAPA and not uncommonly the diagnosis is made in the operating room, when absence of the coronary ostium is noticed after pulmonary arteriotomy.

CABG [28], coronary ostioplasty using azygos vein [29] and pulmonary homograft have all been reported, usually as a salvage treatment if diagnosed intra-operatively [26].

Familial hypercholesterolaemia

FH is the most important cause of premature coronary artery disease. It is an autosomal dominant condition and can result in either homozygous or heterozygous traits. Essentially there is reduced hepatic capacity to clear low-density lipoproteins (LDLs) that leads to sustained exposure of the arterial wall to elevated LDL-C levels leading to accelerated atherosclerosis, especially in the coronary arteries and aorta, and results in premature coronary artery disease [30]. Angina pectoris, myocardial infarction and death in early childhood have been reported [31] and children as young as 7 years have been reported to require CABG for the condition [32]. Myocardial ischaemia in adolescence is mostly due to homozygous familial hypercholesterolaemia (Ho FH) while heterozygous familial hypercholesterolaemia (He FH) usually present in the second decade. Most of these children’s first-degree relatives have died of a coronary event. In homozygous familial hypercholesterolaemia, coronary ostial stenosis is more common, compared with heterozygous familial hypercholesterolaemia where distal coronary artery involvement is more common [33].

Myocardial ischaemia or diagnosis of coronary lesions is indication for CABG. Efforts should rather be directed to identify these patients and prevent development of accelerated premature atherosclerosis by starting early statins [33]. Familial cascade screening is essential and recommended.

Supravalvar aortic stenosis

This is a rare congenital cardiac anomaly seen as part of Williams-Beuren syndrome as well as a result of an isolated autosomal dominant trait secondary to elastin gene deletion, disruption, translocation or mutation [34].

In this condition due to adhesion of the leaflet edge to the narrowed sino-tubular junction, the inflow to the coronary arteries can be compromised and the condition affects the left coronary sinus of Valsalva more commonly [35].

Apart from obstruction of coronary ostia, the coronary arteries are subjected to the elevated prestenotic systolic pressure and undergo premature arteriosclerosis [36]. Besides they also demonstrate primary structural changes seen in elastin arteriopathy [37]. Finally, severe ventricular hypertrophy leads to a critical perfusion mismatch and results in subendocardial ischaemia in these patients.

Any obstruction to coronary blood flow should be identified preoperatively and relieved at the time of surgical repair of supravalvar aortic stenosis. Also, patency of both coronary arteries should be confirmed by intraoperative probing in every case.

Behaviour and selection of conduits in children

The internal thoracic artery (ITA) and the saphenous vein graft (SVG) behave differently in relation to the child’s somatic growth. The SVG lacks longitudinal growth potential and undergoes intimal hyperplasia leading to atherosclerosis whereas the ITA graft has the potential to grow both longitudinally and circumferentially in tune with the child’s somatic growth [38].

There are certain important and unique considerations that dictate graft selection in children. While in general the ITA is considered to be superior to autologous SVG because of the differences in biological properties of the conduits, it is important to take into account the native artery stenosis and the age of the patient when choosing a conduit.

Dissection of left internal thoracic artery (LITA) is also challenging since the vessel is comparatively smaller in calibre and length (due to a small thoracic cavity). More importantly, in low-grade stenosis as often seen in Kawasaki disease, one of the major concerns with ITA usage is its inability to stay patent in the face of competitive flow from native coronary artery. Also, not uncommonly in Kawasaki disease, regression of lesions may occur post CABG, which affects the patency of the grafted ITA (Figs. 2 and 3). Despite this, unless the ITA is completely thrombosed, in almost 25% of cases, the ITA has been seen to regain patency once the competitive flow ceases [13]. Moreover, the ITA endothelium releases nitric oxide (NO) and prostanoids, which relaxes not only the conduit but also the grafted native artery.

Fig. 2.

The left main stem stenosis from the same patient (seen in Fig. 1) underwent complete regression. Shortening of saphenous vein graft, secondary to somatic growth in the child, led to tenting of the LAD. Saphenous vein graft was patent in spite of competitive flow

Fig. 3.

A case of homozygous hypercholesterolaemia (Ho HF)—LDL level > 500 mg/dL. Severe atherosclerosis can affect the subclavian artery and rarely the internal thoracic artery (ITA) as well as seen in this case

With saphenous vein grafts, lack of somatic growth is a major issue and this may lead to not only length shortage of the conduit but also distortion of the native vessel, a finding that has been reported in the literature and has also been seen in our series [38] (Fig. 2). While the advantage of saphenous vein grafts lies in their ability to stay patent even in low-grade stenosis, fibro-proliferative changes in the vein leads to poor long-term patency.

This has led to some surgeons using arterial grafts in non-LAD territories including the right coronary artery (RCA) even with moderate stenosis. Tsuda et al. reported using the right ITA for aneurysmal RCA with moderate stenosis and in order to avoid competitive flow, they completely clipped the RCA beyond the aneurysm. Late follow-up showed patent graft with good distal runoff. This also prevented distal embolism from a relatively open aneurysm [39]. However, the obvious concern with such a procedure is, in the event of graft failure, it would lead to a large area of myocardial loss. Therefore, it is not generally recommended.

Age is also an important consideration for patency and it has been shown that while the long-term patency for the ITA was not significantly influenced by the patient’s age (< 10 or > 10 years), SVG patency was significantly lower for the patients aged less than 10 years [40].

Conduit selection for familial hypercholesterolaemia has different considerations compared with Kawasaki disease. Since these children have very high cholesterol level, venous grafts unequivocally have high occlusion rate. ITA and gastroepiploeic artery remain disease free in patients with familial hypercholesterolaemia and are most commonly used as bypass conduits with good result. In patients with heterozygous familial hypercholesterolaemia, while ITA grafting increased the long-term freedom from reoperations, additional benefits of multiple arterial grafting could not be seen [41].

It is also important to note that in severe cases of familial hypercholesterolaemia, even the ITA may also be affected as seen in one of our patients (Fig. 3), and therefore, ITA injection is always advisable during angiogram. Also, homozygous familial hypercholesterolaemia has extra cardiac involvement, like severe atherosclerotic changes in the ascending aorta and supravalvar stenosis which makes top-end anastomosis of saphenous vein graft very difficult and may also lead to early graft failure.

Apart from the growth potential, pedicled ITA has a calibre similar to the native coronary artery diameter. Besides, the release of NO, the potential to recover from string sign once competitive flow ceases and the fact that ITA grafts which are patent for 1 year remains patent for long make the ITA the best conduit for CABG in children. However, the value of saphenous vein grafts should not be underestimated and care must be taken to allow for the longitudinal growth. A slightly longer vein length positioned with a gentle loop at the time of CABG will compensate for the lack of somatic growth. Using this technique, we have seen that the veins can remain patent even after the patient has doubled his weight over a 5-year period without causing any distortion (Fig. 4a, b).

Fig. 4.

a Coronary CTA 3 months after CABG in a patient 13 years old with Kawasaki disease. b Coronary CTA of the same patient after 5 years. The patient had gained 50 kg during this time. No anastomotic stenosis and growth of the ITA are seen along with no shortening of the saphenous vein graft because a generous loop was created with slightly extra-length at the time of CABG.

Timing of CABG

Timing of CABG in Kawasaki disease has to be carefully evaluated. A study [14] by Kato et al. showed that most of the MI took place within 1 year of diagnosis of Kawasaki disease and about 27% occurred after 1 year. The consequences of the MI were grave with 22% dying during the first attack and 16% of patients having a second MI. Further, it has also been seen that reduced left ventricular (LV) function after a MI was one of the factors responsible for late death after CABG in these children. Thus, these observations would prompt early intervention.

It has also been seen that in almost half the cases of Kawasaki disease, there is regression of aneurysms. This regression can occur between 6 months and 2 years after the initial attack [42, 43]. In view of this observation, careful follow-up of these aneurysms with appropriate anti-coagulant management appears to be a reasonable alternative. However, in the event of any signs of myocardial ischaemia during the follow-up, early intervention must be undertaken. In a very early study by Yamauchi, it was demonstrated that the duration between Kawasaki disease and CABG was the single most determinant of ventricular deterioration and early intervention is therefore generally favoured in presence of indications [16].

The surgical procedure

Procedure should be done preferably through median sternotomy. Alternative approaches like thoracotomy are best avoided because good visibility and good careful anastomosis are the key to the success. CABG can be performed on the beating heart or using conventional cardiopulmonary bypass and cardioplegic arrest depending on the haemodynamic status and surgeon’s experience. Conduit selection should be arterial, unless stenosis is of low grade when veins can be used.

Majority of reports seem to advocate pedicled ITA [13]. However, in our practice, we use skeletonized internal thoracic artery. This is because we can use the proximal part of the ITA which is principally made of elastic fibres as well as for the ease of constructing T-grafts. Moreover, it distends well and provides immediate good flow.

For triple-vessel disease, our favoured strategy is LITA to LAD and right internal thoracic artery (RITA) as a T-graft anastomosed sequentially to circumflex system and posterior descending artery (PDA). If the RITA does not reach right territory because of dilated ventricle, we prefer to use SVG. However, other authors have reported using pedicled gastroepiploeic artery for the distal RCA [44, 45].

Saphenous vein should ideally be used for low-grade stenosis of the coronary artery (< 80% diameter). To deal with lack of somatic growth of saphenous vein grafts, we keep the saphenous vein a little longer than required and place it in a carefully curved lie so as to prevent kinking. Our preference is to harvest veins in children from the thigh as they tend to be of a better quality and have a larger diameter.

Also, care should be taken to handle the vein as little as possible and distension should be avoided. If required, gentle distension is all that should be used [46]. We use 8-0 polypropylene sutures for distal and 6-0 for proximal anastomosis. However, authors have reported using 9-0, 10-0 and 11-0 sutures using high-magnification surgical glasses or microscopes [47]. We do distals with continuous sutures, but interrupted sutures are often used to allow for growth and prevent anastomotic stenosis. However, in our series using continuous sutures, we have not encountered any anastomotic stenosis even when the child has gained more than twice the body weight.

Patch enlargement of coronary ostial stenoses in supra-valvular aortic stenosis has been described, and also mammary artery bypass grafting has been performed in children with long-segment coronary artery stenosis [48].

The surgeon

There is an interesting dilemma about who should be operating on these children requiring coronary artery bypass grafting. Paediatric cardiac surgeons do not usually perform coronary artery bypass grafts and adult cardiac surgeons are not normally used to operating on small children. While in India there are still paediatric cardiac surgeons who also perform CABG in adults, this is rare in the Western world. To address this situation, some authors have recommended that training of contemporary congenital heart surgeons should also include performing CABG using ITA in children [49]. However, until that time, a joint procedure with the paediatric cardiac surgeon assisted by an adult coronary surgeon may be another option.

Graft patency

Superiority of arterial graft over vein graft has been shown in many studies. In one such study, the 20-year graft patency for ITA was 87% which was significantly better compared with saphenous vein grafts which was only 44% at 20 years. This superiority was consistently seen even in the non-LAD territory with the 20-year patency of LITA being 87% as opposed to 42% for vein grafts [40].

Age at which CABG is being carried out is also an important determinant of patency. The effect of age on patency is more exaggerated in the context of veins. Twenty-five-year patency rate for the SVG, when used in children of less than 10 years of age, was only 25% compared with 42% when used in children above the age of 10 years. However, age does not seem to exert much influence on patency of ITA which shows similar patency at 25 years (87% vs. 86%) when used above or below 10 years of age [40].

Similar reports on superiority of ITA over SVG are available in children 12 years or less. While patency of ITA grafts at 1, 5 and 15 years was reported at 93%, 73% and 65%, that of SVG was significantly lower at 65%, 53% and 48% respectively.

While there are reports of using both the gastroepiploeic artery [50] and the radial artery [51] in children, long-term patency data in children is not available [11].

Use of bilateral ITA, when possible, is the recommended conduit strategy and harvesting bilateral ITA does not appear to result in any adverse effects on the thoracic development of children [44].

Long-term results and survival

Long-term data for paediatric CABG is primarily available from follow-up of children with Kawasaki disease. A large series by Kitamura reported excellent long-term outcomes in these patients with 10-year survival rate of 98% and a 25-year survival rate of 95% [40].

The benefits of CABG in the paediatric population were stressed by another study that showed that in presence of aneurysms > 8 mm, CABG improved the 30-year survival to 62% compared with 36% without CABG [52].

The quality of life in presence of a functioning graft, usually an ITA, is also remarkably good with more than 80% of children enjoying athletic programs at school, more than 84% taking up jobs and integrating into society without specific limitations. Also, several female patients have had successful pregnancies and child births [37, 38].

Our experience

In our small series of five patients needing CABG in childhood, 4 (80%) were due to Kawasaki disease. The only other patient had homozygous hypercholesterolaemia. The mean age in our series was 11.2 ± 2.3 years (range 8–14). One case was operated on an emergency basis while majority (n = 4) were operated electively. An ITA was used in all except one case of Ho HF (Fig. 3). We were able to use the ITA even in the case requiring emergency CABG. All patients are being followed up with CTA. There was no in-hospital mortality, and at a mean follow-up duration of 45.2 ± 48.8 months (range 18–132 months), all grafts remain patent.

Summary

Coronary artery disease in children is a unique condition that requires a high index of suspicion as it is notoriously difficult to diagnose and results in grave consequences when missed. Presentation of coronary disease is very variable owing to congenital, acquired and iatrogenic aetiology. Lesions may regress over a period of time and decision-making regarding timing of intervention and choice of conduit are as important as the procedure itself. Dilemma exists over whether adult or paediatric cardiac surgeons should perform the CABG in children. The procedure itself is challenging and requires high level of dexterity and careful planning. As CABG in children is still quite uncommon, it is difficult to acquire significant experience and perhaps creation of regional specialized centres with a wide referral base may be the way forward to provide high-end care to these children. Though single balloon dilation of anastomotic stenosis has shown good long-term patency, PTCA and stenting have not been very successful in children. Graft-related concerns like anastomotic growth, somatic growth and long-term patency have always been a concern and mostly can be overcome by using ITA.

Coronary artery disease in children is difficult to diagnose. CABG in children is on the rise and ITA is the conduit of choice.

Compliance with ethical standards

Conflict of interest

The authors declare that there are no conflicts of interest.

Funding

Nil.

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