Arterial switch operation: Myocardial ischemia reversed by internal mammary artery graft

Outcomes after surgical coronary artery revascularisation in children with congenital heart disease

OBJECTIVE

Surgical coronary revascularisation in children with congenital heart disease (CHD) is a rare event for which limited information is available. In this study, we review the indications and outcomes of surgical coronary revascularisation from the Pediatric Cardiac Care Consortium, a large US-based multicentre registry of interventions for CHD.

METHODS

This is a retrospective cohort study of children (<18 years old) with CHD who underwent surgical coronary revascularisation between 1982 and 2011. In-hospital mortality and graft patency data were obtained from the registry. Long-term transplant-free survival through 2014 was achieved for patients with adequate identifiers via linkage with the US National Death Index and the Organ Procurement and Transplantation Network.

RESULTS

Coronary revascularisation was accomplished by bypass grafting (n=72, median age 6.8 years, range 3 days-17.4 years) or other operations (n=65, median age 2.6 years, range 5 days-16.7 years) in 137 patients. Most revascularisations were related to the aortic root (61.3%) or coronary anomalies (27.7%), but 10.9% of them were unrelated to either of them. Twenty in-hospital deaths occurred, 70% of them after urgent 'rescue' revascularisation in association with another operation. Long-term outcomes were available by external linkage for 54 patients surviving to hospital discharge (median follow-up time 15.0 years, max follow-up 29.8 years) with a 15-year transplant-free survival of 91% (95% CI 83% to 99%).

CONCLUSIONS

Surgical coronary revascularisation can be performed in children with CHD with acceptable immediate and long-term survival. Outcomes are dependent on indication, with the highest mortality in rescue procedures.

Pediatric Coronary Artery Bypass Surgery for Congenital Heart Disease

BACKGROUND

Pediatric coronary artery bypass surgery (PCABS) for congenital heart disease has become increasingly important in infants and children undergoing modern cardiac surgical procedures, because of its life-saving potential in unsuccessful coronary transfer operation. This review summarizes the current surgical role of PCABS for treating congenital heart diseases.

METHODS

Databases, mainly PubMed, were searched for relevant publications about coronary bypass operation in the pediatric population, from 1970 (commencement) to March 2018.

RESULTS

The five main indications were (1) anomalous origin of the left coronary artery from the pulmonary artery, (2) left main coronary trunk atresia, (3) acute and late coronary events in the arterial switch operation for transposition of the great arteries, (4) the Ross operation for congenital aortic stenosis complicated by destructive infective endocarditis, and (5) inadvertent coronary artery injury during heart operation. Direct coronary reimplantation (coronary transfer) in most and surgical angioplastic procedures in selected patients were the first choice; however, PCABS with internal thoracic artery (ITA) grafts can be lifesaving in emergency or severe myocardial hypoperfusion conditions. Because the patency of saphenous vein grafts is poorer than that of ITA grafts, their use should be avoided in growing children. The procedure can be performed safely in neonates, infants, and small children, using high-power magnifying glasses or a surgical microscope.

CONCLUSIONS

Long-term results of survival and ITA graft function are excellent in growing children and adults. Congenital heart surgeons should be trained in quick graft takedown and in coping with emergency and late devastating complications in coronary transfer operation.

Coronary Artery Involvement of Williams Syndrome in Infants and Surgical Revascularization Strategy

Williams syndrome (WS) is a genetic disorder due to deficiency of elastin gene expression. It is characterized by typical somatic abnormalities and a wide range of cardiovascular malformations. Coronary artery involvement is a frequent finding of the syndrome, particularly in those patients with severe supravalvular aortic stenosis. We present the case of an 11-month-old infant affected by WS who developed severe coronary artery disease 2 months after the surgical repair of supravalvular aortic stenosis. The clinical picture and successful surgical revascularization strategy is also described.

Molecular aspects of development and regulation of endometriosis

Endometriosis is a common and painful condition affecting women of reproductive age. While the underlying pathophysiology is still largely unknown, much advancement has been made in understanding the progression of the disease. In recent years, a great deal of research has focused on non-invasive diagnostic tools, such as biomarkers, as well as identification of potential therapeutic targets. In this article, we will review the etiology and cellular mechanisms associated with endometriosis as well as the current diagnostic tools and therapies. We will then discuss the more recent genomic and proteomic studies and how these data may guide development of novel diagnostics and therapeutics. The current diagnostic tools are invasive and current therapies primarily treat the symptoms of endometriosis. Optimally, the advancement of "-omic" data will facilitate the development of non-invasive diagnostic biomarkers as well as therapeutics that target the pathophysiology of the disease and halt, or even reverse, progression. However, the amount of data generated by these types of studies is vast and bioinformatics analysis, such as we present here, will be critical to identification of appropriate targets for further study.

Pediatric Applications of Surgical Patch Angioplasty of the Main Coronary Trunks

Objectives:

Obstruction of the main coronary trunks, although rare among the general pediatric population, remains an important complication of the arterial switch operation (ASO). Surgical patch angioplasty (SPA) is a technique whereby myocardial revascularization is achieved through direct ostial enlargement, restoring antegrade coronary flow, avoiding competitive flow, and preserving conduit material. This study investigates the indications, techniques, and outcomes of SPA in the pediatric population.

Methods:

A systematic literature review identified 15 studies incorporating 92 patients. The primary outcome of interest was 30-day mortality. Secondary outcomes included 30-day major adverse cardiac and cerebrovascular events, mortality at last follow-up, reintervention rate, symptomatic status, angiographic patency, and myocardial perfusion status at last follow-up.

Results:

The SPA was most frequently performed to treat ostial occlusion as a complication of the ASO (73.9%). Of the procedures, 77.2% involved the left main stem, 8.7% the left anterior descending artery, and 14.1% the right coronary artery. Saphenous vein was the commonest patch type (60.9%) followed by autologous pericardium (23.9%). Of the procedures, 96.7% were considered successful with an uneventful postoperative recovery. Overall hospital mortality was 2.2%. At a mean of 39 months of follow-up, 84.8% of the patients were asymptomatic, 51.1% of the repairs were angiographically patent, 9.8% had myocardial perfusion defects, and 6.5% required repeat revascularization.

Conclusion:

Current evidence suggests that SPA shows encouraging outcomes in a pediatric population and, with increasing experience, may provide a definitive solution to coronary artery occlusion.

Outcome of coronary artery bypass grafting performed in young children

OBJECTIVES

The long-term patency rate of coronary artery bypass grafting for which arterial grafts are used is known to be high in the pediatric population. However, this issue remains uncertain in children under 3 years of age. Here, we report the outcome in this specific population.

METHODS

From July 1988 to July 2007, 18 children less than 3 years of age (age at operation, 0.1-35 months; median, 4 months) underwent 20 coronary artery bypass graft operations using an arterial graft. Indications for bypass grafting were coronary artery complications related to the arterial switch operation for transposition of the great arteries in 12 patients (coronary obstruction in 8 patients, peroperative coronary anomalies precluding coronary transfer in 4 patients), congenital anomalies of the coronary arteries in 4 patients, and Kawasaki disease in 2 patients.

RESULTS

After a mean follow-up of 55 months (range, 1-176 months; median, 41 months), patency of 19 bypass grafts was assessed. One was occluded and 2 have necessitated a percutaneous procedure. Two patients died suddenly (1 with an occluded graft and 1 with a patent graft and hypertrophic myocardiopathy) 3.5 and 4.6 months, respectively, after bypass grafting.

CONCLUSIONS

Coronary artery bypass grafting should be considered as a possible alternative for coronary revascularization in young children. Although our series shows quite a good patency rate, this procedure remains a technical challenge and requires careful follow-up.

Segmental Wall-Motion Abnormalities After an Arterial Switch Operation Indicate Ischemia

We prospectively studied 29 consecutive neonates undergoing an arterial switch operation to determine if segmental wall motion abnormalities (SWMA) represented myocardial ischemia. Intraoperative transesophageal echocardiogram was recorded at baseline and twice after cardiopulmonary bypass. Cardiac troponin I (cTnI) levels were measured before sternal incision and 3, 6, 12, 24, 48, and 72 h after removal of the aortic cross-clamp. Immediate postoperative Holter and 15-lead electrocardiograms (ECG) were evaluated for ischemia. Transthoracic echocardiograms were obtained before hospital discharge. At bypass termination, immediately after protamine administration, segmental wall motion was normal in nine neonates and abnormal in 20. SWMA were transient in five and present at the time of chest closure in 15 neonates. Neonates in whom SWMA were present at chest closure had more segments involved than those in whom SWMA were transient (P > 0.001). Neonates with SWMA at chest closure had higher cTnI levels postoperatively versus neonates with normal wall motion (P = 0.02). Postoperative ECG data were available in 26 neonates. There was ECG evidence of myocardial ischemia in two of eight neonates with normal wall motion, one of five with transient SWMA, and nine of 13 with SWMA at chest closure. CTnI levels at 12, 24, and 48 h and intraoperative SWMA were predictive of postoperative SWMA. We believe these data indicate that SWMA, which persist at the completion of an arterial switch operation, and which are present in multiple myocardial segments, correlate with myocardial ischemia. Further follow-up of these patients is needed to determine if increased intraoperative myocardial ischemia correlates with long-term outcomes.

Autologous patch angioplasty of the left main coronary artery in a pediatric patient: 7-year follow-up

We present a patient who developed ischemia after an arterial switch procedure for transposition of the great vessels secondary to left coronary artery stenosis. The excellent intermediate-term result of patch angioplasty of the left main coronary artery with the use of an internal thoracic artery patch is outlined.

Surgery of the complete atrioventricular canal: relationship between age at operation, mitral regurgitation, size of the ventricular septum defect, additional malformations and early postoperative outcome

The perioperative risk after repair of the complete atrioventricular canal is reported to be low provided there is a balanced relationship of both ventricles, and elevated pulmonary vascular resistance has been demonstrated to be reversible. However, some pre- and perioperative conditions may adversely affect early postoperative outcome. A consecutive series of 42 patients (mean age 8.5 months, 34/42, 81%, with trisomy 21) operated between 1994 and 1998 was analyzed prospectively for pre- and perioperative risk factors. Echocardiography alone was performed in 35 patients whereas cardiac catheterization was performed in 7 patients aged more than 18 months to confirm operability. Additional malformations were found in 20 patients. Early mortality was 2.3% (1/42), and postoperatively a low cardiac output was observed in 25 patients (59%); NO inhalation was used in 12 patients. Only the size of the ventricular septal defect (> than the diameter of the aortic annulus) could be identified as a predictor of adverse postoperative outcome in multivariate analysis. The presence of associated intracardiac malformations showed a trend to increased perioperative risk in multivariate analysis. Early results after repair of the complete atrioventricular canal are excellent. Survival, postoperative morbidity and normalization of pulmonary artery pressure can be related to the size of the ventricular septal defect. Continuous monitoring of the pulmonary artery pressure (with consequent NO application when indicated) is probably responsible for the low perioperative risk encountered in this series, despite the high incidence of postoperative pulmonary artery hypertension.

Pediatric coronary artery bypass for Kawasaki congenital, post arterial switch, and iatrogenic lesions

BACKGROUND

Pediatric coronary artery bypass (PCAB) has been recently employed for expanding indications to treat acquired, congenital, post arterial switch, and other iatrogenic pediatric coronary artery problems.

METHODS

Between 1987 and 1998, 3 infants and 13 children (n = 16, mean age 6.1 years, range 2 months-18 years) underwent one or more internal thoracic artery (ITA) to coronary artery (CA) bypass grafts for Kawasaki disease (n = 4), congenital lesions (n = 3), post arterial switch (n = 4), and other iatrogenic obstructions (n = 5). Proximal left main CA arterioplasty was performed concurrently with ITA-CA bypass in 4 patients.

RESULTS

Survival is 93.8%. All bypass grafts in surviving patients are patent 2 months-11 years postoperation. The 11 elective patients are well (NYHA I-II). The 5 emergent operations were performed in 2 infants and 3 adolescents who had poor ventricular function prior to ITA-CA bypass due to iatrogenic injuries in 3, congenital critical left main stenosis in 1, and intraoperative iatrogenic coronary injury in 1. The 3 adolescents fared worse, resulting in death in the first, cardiac transplantation in the second, and full recovery in the third. The 2 infants have steadily improving ventricular function.

CONCLUSIONS

ITA-CA bypass can be successfully performed in infants and children for expanding elective and life-saving indications with excellent results. Poor preoperative ventricular function often persists, especially in those older children with iatrogenic injuries, and may result in death or cardiac transplantation.

Internal mammary artery to coronary artery bypass in paediatric cardiac surgery

The internal mammary artery is regarded as the optimal conduit for coronary artery bypass grafting in adults. Use of this conduit in paediatric surgery is rare and has been reported mainly in patients with Kawasaki's disease. We report five patients who required internal mammary-coronary artery grafting due to adverse anatomical disposition of the coronary artery. In two cases an internal mammary graft was required during correction of transposition of the great arteries. The other cases involved correction of a left coronary artery arising anomalously from the pulmonary artery. Late angiography shows satisfactory growth and patency of the conduits.

[Arterial switch: aortocoronary bypass with interposition of polytetrafluoroethylene (Gore-tex) vascular graft]

We report a case of an infant with transposition of the great arteries accompanied by an unusual coronary artery pattern, in whom an expanded polytetrafluorethylene (Gore-tex) graft to the right coronary artery was used during surgical correction (switch arterial), with a postsurgical follow-up time of 8 months.

Long-term results of arterial switch repair of transposition of the great vessels

The arterial switch operation has become the preferred surgical procedure for transposition of the great arteries worldwide. The low operative mortality at "low-risk" institutions has been well documented. The advantages of the arterial switch compared with atrial-level repairs include a lower incidence of arrhythmias and the likelihood of normal systemic ventricular function over the long term. However, the long-term sequelae of this operation must be continually evaluated, including the fate of the supravalvular pulmonary and aortic anastomoses, growth of the aortic root, competency of the neoaortic valve, patency of the coronary arteries, effects on the conduction system, and adequacy of ventricular function. These anatomic results, as well as the neurodevelopmental outcomes of these patients, are summarized in this review. Copyright 1998 by W.B. Saunders Company