Neonatal arterial switch operation: coronary artery patterns and coronary events

Techniques and pitfalls of coronary arterial reimplantation in anatomical correction of transposition

BACKGROUND AND AIM

We assessed the anatomical variations in coronary arterial patterns relative to the techniques of reimplantation in the setting of the arterial switch operation, relating the variations to influences on outcomes.

METHODS

We reviewed pertinent published investigations, assessing events reported following varied surgical techniques for reimplantation of the coronary arteries in the setting of the arterial switch procedure.

RESULTS

The prevalence of reported adverse events, subsequent to reimplantation, varied from 2% to 11%, with a bimodal presentation of high early and low late incidence. The intramural pattern continues to contribute to mortality, with some reports of 28% fatality. The presence of abnormal course relative to the arterial pedicles in the setting of single sinus origin was associated with a three-fold increase in mortality. Abnormal looping with bisinusal origin of arteries was not associated with increased risk.

CONCLUSION

The techniques of transfer of the coronary arteries can be individually adapted to cater for the anatomical variations. Cardiac surgeons, therefore, need to be familiar with the myriad creative options available to achieve successful repair when there is challenging anatomy. Long-term follow-up will be required to affirm the superiority of any specific individual technique. Detailed multiplanar computed-tomographic scanning can now reveal all the variants, and elucidate the mechanisms of late complications. Coronary angioplasty or surgical revascularization may be considered in selected cases subsequent to the switch procedure.

Safety of Normothermic Cardiopulmonary Bypass in Pediatric Cardiac Surgery: A System Review and Meta-Analysis

Objectives: Hypothermic cardiopulmonary bypass (HCPB) has been used successfully in cardiac surgery for more than half a century, although adverse effects have been reported with its use. Many studies on temperature management during CPB published to date have shown that normothermic CPB (NCPB) provides more benefits to children undergoing cardiac surgery. The present meta-analysis investigated the effect of NCPB on clinical outcomes based on results of randomized controlled trials and observational studies on pediatric cardiac surgery. Methods: Databases such as PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Clinical Trials.gov were searched from inception to May 2021 to identify relevant studies published in English. Results: The present meta-analysis included 13 studies characterizing a total of 837 pediatric patients. The random effects model exhibited that the NCPB group had reduced revision for postoperative bleeding [odds ratio (OR): 0.11; 95% confidence interval (CI): 0.01-0.89; I ² = 0%, P = 0.04], serum lactate 2-4 h after CPB (mean difference: -0.60; 95% CI: -1.09 to -0.11; I ² = 82%, P = 0.02), serum creatinemia 24 h after CPB (mean difference: -2.73; 95% CI: -5.06 to -0.39; I ² = 83%, P = 0.02), serum creatinemia 48 h after CPB (mean difference: -2.08; 95% CI: -2.78 to -1.39; I ² = 0%, P < 0.05), CPB time (mean difference: -19.10, 95% CI: -32.03 to -6.18; I ² = 96%, P = 0.04), and major adverse events (OR: 0.37; 95% CI: 0.15-0.93; Z = 2.12, P = 0.03) after simple congenital surgery compared with the HCPB group. Conclusion: NCPB is as safe as HCPB in pediatric congenital heart surgery. Moreover, NCPB provides more advantages than HCPB in simple congenital heart surgery.

Outcomes after Arterial Switch Operation for Simple Transposition

Without intervention, babies born with transposed great arteries (TGA) are doomed to a rapid death. Jatene and coworkers deserve the credit for performing the first successful arterial switch operation (ASO) in a patient with TGA and ventricular septal defect (VSD) in 1975. Since then ASO has become the procedure of choice in most medical centers. This review article summarizes the historical aspects of arterial switch operation and assesses this procedure's outcomes.

Cardiac autonomic function in adolescents operated by arterial switch surgery

BACKGROUND

Children with transposition of the great arteries, in whom an arterial switch operation (ASO) is performed, have been shown to have an increased incidence of sudden death, which may be due to cardiac autonomic imbalance and repolarisation instability. We hypothesised that i) cardiac norepinephrine (NE) kinetics and ii) arterial baroreflex sensitivity (BRS), reflecting sympathetic activity and vagal function respectively, are altered in this group.

METHODS AND RESULTS

17 children (15.8 ± 1.5 years of age) with ASO-surgery in the neonatal period were studied. 17 had cardiac BRS assessed by spontaneous fluctuations of systolic blood pressure and RR-interval, and repolarisation was measured as QT variability index. Matched healthy subjects were controls. Cardiac vagal function and repolarisation pattern were unchanged following ASO-surgery. At cardiac catheterisation, we infused tritiated NE in 8 of these children to examine total body and cardiac sympathetic function at baseline and following 5 min of adenosine infusion to induce reflex sympathetic activation. Blood was sampled simultaneously from the aorta and coronary sinus. Cardiac fractional extraction of ([3H])NE was substantially lower in operated children, being 56 ± 10 vs. 82 ± 9% (p=0.0001). Following i.v. adenosine in the operated group, NE total body spillover doubled vs. baseline (p<0.002) and the coronary venous-arterial concentration gradient of ([3H])dihydroxyphenylglycol increased 4-fold (p=0.04).

CONCLUSIONS

Arterial switch operation performed neonatally appears to leave cardiac vagal function intact and, although cardiac sympathetic activation in response to adenosine occurs, cardiac neuronal NE reuptake is impaired. This may be pro-arrhythmic by reducing removal capacity of NE from the cardiac synaptic cleft.

Clinical features and surgical outcomes of complete transposition of the great arteries

Purpose

This single-center study aimed to assess the clinical features and surgical approaches and outcomes of complete transposition of the great arteries (TGA).

Methods

TGA patients who had undergone surgical correction at the Kyungpook National University Hospital from January 2000 to December 2010, were retrospectively evaluated for patient characteristics, clinical manifestation, preoperative management, intraoperative findings, postoperative progress, and follow-up status.

Results

Twenty-eight patients (17 boys and 11 girls, mean age=10.6±21.5 days) were included and were categorized as follows: group I, TGA with intact ventricular septum (n=13); group II, TGA with ventricular septal defect (VSD, n=12); and group III, TGA/VSD with pulmonary stenosis (n=3). Group I underwent the most intensive preoperative management (balloon atrial septostomy and prostaglandin E1 medication). Group II showed the highest incidence of heart failure (P<0.05). Usual and unusual coronary anatomy patterns were observed in 20 (71%) and 8 patients, respectively. Arterial and half-turned truncal switch operations were performed in 25 and 3 patients (Group III), respectively. Postoperative complications included cardiac arrhythmias (8 patients), central nervous system complications (3 patients), acute renal failure (1 patient), infections (3 patients), and cardiac tamponade (1 patient), and no statistically significant difference was observed between the groups. Group II showed the mildest aortic regurgitation on follow-up echocardiograms (P<0.05). One patient underwent reoperation, and 1 died. The overall mortality rate was 4%.

Conclusion

Our study showed favorable results in all the groups and no significant difference in postoperative complication, reoperation, and mortality among the groups. However, our results were inadequate to evaluate the risk factors for reoperation and mortality owing to the small number of patients and short follow-up duration.

[Prognostic evaluation of arterial switch in the transposition of great arteries]

INTRODUCTION AND OBJECTIVES

The arterial switch is the procedure of choice for transposition of great arteries, with or without ventricular septal defect. The aim of this study was to identify risk factors for hospital mortality.

METHODS

The study included 121 children between January 1994 and June 2008. Of these, 80 (66%) were diagnosed with intact ventricular septum, and 41 (34%) with ventricular septal defect. Variables were collected pre-operatively, during surgery, and postoperatively.

RESULTS

The mean age was 11 [8 to 16] days and a mean weight of 3.5 [3.0 to 3.7] kg. A ventricular septal defect was closed in 11 children (9.1%). A total of 81.8% had a normal coronary pattern. There was delayed closure of the chest in 38 patients (31.4%). The hospital mortality was 11.6%, decreasing over the past 5 years to 2.1%. The weight, abnormal coronary pattern, time of cardiopulmonary bypass, mean arterial pressure at admission, pulmonary dead space, and delayed closure of the chest, were risk factors of mortality. The model that best predicts death, consists of the mean arterial pressure at admission, and delayed closure of the chest.

CONCLUSIONS

The reduction in extracorporeal circulation time and the use of delayed closure of the chest, have helped to reduce mortality. The abnormal coronary pattern remains a risk factor for mortality. In children with delayed closure of the chest, a mean arterial pressure at admission ≥ 47.5 mmHg is a goal to achieve.

Late Complications Following the Arterial Switch Operation

The arterial switch operation has been the principal treatment for transposition of the great arteries and its variants for the last 25 years. Early mortality has decreased significantly over time, but long-term complications include pulmonary artery stenosis, coronary artery obstruction, neoaortic valvar insufficiency, arrhythmia, and aortic arch obstruction. This article provides an overview of the history, anatomic patterns, surgical results, and possible operative solutions discussed in the literature for patients with transposition of the great arteries who undergo arterial switch operations that result in late complications. Published journal articles were identified through PubMed literature search. The authors selected 72 articles for analysis. It is concluded that modifications can be made to the arterial switch operation in an effort to meet the challenges presented by late complications.

Myocardial perfusion magnetic resonance imaging for detecting coronary function anomalies in asymptomatic paediatric patients with a previous arterial switch operation for the transposition of great arteries

BACKGROUND

The main cause of long-term morbidity and mortality after the arterial switch operation for transposition of great arteries is complication at the coronary arteries. Myocardial perfusion magnetic resonance imaging represents a relatively novel and appealing tool for detecting myocardial ischaemia but with little experience in paediatric patients. The purpose of this paper is to report a single centre experience with myocardial perfusion magnetic resonance imaging for detecting ischaemia after the arterial switch operation for transposition of great arteries.

METHODS

Twenty-eight patients aged 13-16 years with an arterial switch operation for transposition of great arteries were included in the study. Coronary pattern, operative and postoperative complications, and long-term follow-up events were reviewed. Patient functional evaluation included clinical examination, electrocardiogram and echocardiogram. Every patient underwent magnetic resonance imaging perfusion scanning at rest and under adenosine-induced stress.

RESULTS

All patients were symptom free with no ischaemic signs on the electrocardiogram. All magnetic resonance imaging examinations were generally well tolerated with minor adenosine secondary effects in 36% of the patients. Two stress myocardial perfusion magnetic resonance studies were excluded from analysis for technical reasons. No perfusion stress defects were detected at the remaining 26. Myocardial delayed enhancement was performed in all 28 patients. In five subjects, a subendocardial late enhancement consistent with patch tissue for septal defect closure at the time of repair was indentified.

CONCLUSION

Magnetic resonance imaging evaluation of myocardial perfusion and viability is feasible in paediatric patients long after arterial switch operation. No signs of myocardial ischaemia or necrosis were documented in this young asymptomatic population. Further studies including coronary angiography correlation are needed to validate magnetic resonance imaging results.

A study of the physiological consequences of sympathetic denervation of the heart caused by the arterial switch procedure

BACKGROUND

The arterial switch operation is the corrective operation for transposition of the great arteries, defined as the combination of concordant atrioventricular and discordant ventriculo-arterial connections, but there have been concerns about silent subendocardial ischaemia on exercise and coronary artery growth. The arterial switch divides the majority of the sympathetic nerves entering the heart; we have studied the effects of coronary flow and sensitivity to catecholamine stimulation in an animal model.

METHODS

A total of 10 piglets were operated on cardiopulmonary bypass with section and resuturing of aortic trunk, pulmonary artery and both coronary arteries, with 13 sham-operated controls. After 5-7 weeks of recovery, seven simulated switch survivors and 13 controls were studied.

RESULTS

Basal heart rate was significantly higher in switch piglets: in vivo mean (standard deviation) 112 (12) versus sham 100 (10) beats per minute, (p = 0.042); in vitro (Langendorff preparation): 89 (9) versus sham 73 (8) beats per minute (p = 0.0056). In vivo maximal heart rate in response to epinephrine was increased in switch piglets, 209 (13) versus 190 (17) beats per minute (p = 0.044). In vitro dose-response curves to norepinephrine were shifted leftward and upwards (p = 0.0014), with an 80% increase in heart rate induced by 0.095 (0.053) norepinephrine micromole per litre perfusate in switch hearts versus 0.180 (0.035) norepinephrine micromole per litre (p = 0.023). Increase in coronary flow on norepinephrine stimulation and maximal coronary flow were significantly reduced in switch hearts: 0.3 (0.2) versus 0.8 (0.4) millilitre per gram heart weight (p = 0.045) and 2.5 (0.4) versus 3.1 (0.4) millilitre per gram heart (p = 0.030), respectively.

CONCLUSIONS

A combination of increased intrinsic heart rate, increased sensitivity to chronotropic actions of norepinephrine, and a decreased maximal coronary flow creates potential for a mismatch between perfusion and energy demands.

Current Risk Factors and Outcomes for the Arterial Switch Operation

BACKGROUND

The arterial switch operation is the preferred treatment for dextrotransposition of the great arteries and some forms of double-outlet right ventricle.

METHODS

All patients undergoing an arterial switch operation at a single institution from January 1, 1999, to September 1, 2005, were reviewed.

RESULTS

Of the 168 patients, median age was 2 days (range, 0 to 358) and weight was 3.5 kg (range, 1.9 to 11.8 kg). Eleven patients were less than 36 weeks gestational age. Forty percent had coronary patterns other than usual. Mean cardiopulmonary bypass (CPB) time was 147 +/- 45 minutes, and mean cross-clamp time was 77 +/- 27 minutes. At a mean follow-up of 19 +/- 21 months, there were 10 (6%) hospital and 4 (3%) late deaths. Actuarial 1-month, 1-year, and 3-year survivals were 94%, 90%, and 89%, respectively. Bivariate analysis revealed weight less than 2.5 kg (p = 0.032), gestational age less than 36 weeks (p = 0.002), and CPB time greater than 150 minutes (p = 0.0075) decreased hospital survival. Intermediate-term survival was negatively impacted by weight less than 2.5 kg (p = 0.017), gestational age less than 36 weeks (p = 0.0096), CPB time greater than 150 minutes (p = 0.0050), and age at presentation greater than 4 weeks (p = 0.034). By multivariate analysis, gestational age less than 36 weeks (p = 0.0051) and CPB time greater than 150 minutes (p = 0.016) were independent risk factors for hospital mortality. Gestational age less than 36 weeks (p = 0.0096) and CPB time greater than 150 minutes (p = 0.005) were also independent predictors of intermediate-term mortality. Coronary anatomy could not be shown to affect survival, including no deaths among the 12 patients with intramural coronaries.

CONCLUSIONS

The arterial switch operation can be performed with low mortality regardless of diagnosis or coronary pattern. The premature patient and minimizing CPB time remain as challenges to optimize outcomes for the arterial switch operation.

Early and mid-term outcome of the arterial switch operation in 114 consecutive patients

BACKGROUND

The arterial switch operation (ASO) has become the treatment of choice in patients with simple or complex transposition of the great arteries (TGA). The purpose of this study was to assess early and mid-term outcome after ASO in a single centre.

PATIENTS AND METHODS

Between 1995 and December 2005, 114 consecutive patients underwent an ASO at our institution, performed by one single surgeon. Patients charts, surgical reports and echocardiograms were retrospectively reviewed. Patients were analyzed in 3 different groups: Group I consisted of 77 neonates with TGA and intact ventricular septum, group II of 13 patients with TGA and ventricular septal defect which had to be closed surgically and group III of 24 patients with various forms of TGA in a complex setting. The patient's median weight was 3.23 kg (1.65-8.30). Twenty-five neonates were born preterm, 18 were diagnosed prenatally. Median follow-up time was 20.7 months (0.3-128.6).

RESULTS

The thirty day mortality was 1.75% (2/114), late mortality 0.88% (1/112) accounting for an overall mortality of 2.63%. There was only one early coronary event and so far no late events. Ten of 111 survivors required reoperation, all but 1 from group III. Prevalence of supravalvular pulmonary stenosis was 4.7%. Freedom from reoperation at 5 years of follow-up time was 87.5%. One patient required permanent pacing, no other late arrhythmias occurred. In our series the only risk factor for increased mortality and morbidity was a body weight of less than 2500 g at the time of operation. No better outcome could be demonstrated in the prenatally diagnosed patients.

CONCLUSION

The ASO can be performed safely and with low mortality and morbidity even in patients with complex TGA. Follow-up of these patients is required to detect residual problems like supravalvular pulmonary stenosis, coronary problems, arrhythmias and aortic valve dysfunction.

Physiologic versus anatomic repair of congenitally corrected transposition of the great arteries: meta-analysis of individual patient data

The objective of this meta-analysis of individual patients' data was to compare the immediate outcomes of anatomic and physiologic repair of congenitally corrected transposition of the great arteries. Eleven nonrandomized studies, involving 124 patients, met the inclusion criteria for this review. The Rastelli type anatomic repair and the era of surgery were significantly related to the outcome in different tested models. Entering all variables into the logistic regression model showed a significant protective effect of the Rastelli type anatomic repair (odds ratio = 0.05, 95% confidence interval: 0.01, 0.50, p = 0.02).

Pathology of coronary narrowing after arterial switch operation: autopsy findings in two patients who died within 3 months of surgical treatment and review of the literature

The arterial switch operation (ASO) has become the surgical treatment of choice for transposition of the great arteries (TGA). Myocardial ischemia owing to coronary complication remains the commonest cause of mortality and morbidity following ASO. The main clinical manifestations of coronary obstruction reported after a switch procedure are heart failure, arrhythmias, or sudden death. Coronary complications are responsible for about 50% of early death and for almost all late deaths. We describe pathologic and anatomic findings in two cases of late sudden death after an ASO. Critical intimal thickening and acute take-off of coronary trunks were the main pathological substrates of death. Histological examination revealed an obstructive coronary proliferation characterised by a concentric stratum of intimal smooth muscle cell hyperplasia with preserved tunica media. Pathogenetic assessment of intimal coronary lesions after an ASO should consider the role of endothelium and vascular parietal wall in the unavoidable response to injury caused by arterial reconstruction. Since a rapidly progressive proliferative disease is suspected, to explain coronary narrowing, understanding endothelial biology and improving surgical technique should help to prevent late coronary events.

Selective timing for the arterial switch operation

BACKGROUND

To determine outcomes for the arterial switch operation individualized according to the underlying anatomy and clinical status.

METHODS

A retrospective review of a consecutive series of infants less than 90 days of age who underwent the arterial switch operation at a single institution.

RESULTS

From July 1993-April 2001, 117 infants underwent an arterial switch operation before 90 days of age. Seventy-five patients (64%) had transposition of the great arteries with intact ventricular septum with the aim of operation before 14 days of age; however, 8 of these patients had delayed presentation (range 15-46 days). Thirty-five patients (30%) had transposition with a ventricular septal defect (30 patients) or double outlet right ventricle (5 patients) and normal arch anatomy and were repaired within the first 90 days of life depending on the severity of heart failure at a median of 12 days of age (range 3-83 days). Seven patients (6%) had associated aortic coarctation (5 patients) or interrupted aortic arch (2 patients). One patient died during hospitalization (0.85% hospital mortality) and one patient died from noncardiac causes during a median follow-up of 35 months (1.7% total mortality). Four patients required intervention during follow-up (3.4%) for new aortic coarctation (2 patients), supravalvar pulmonic stenosis (1 patient), or right hemi-diaphragm paralysis (1 patient).

CONCLUSIONS

Individualized timing for the arterial switch operation within the first ninety days of life produces excellent survival rates for all types of transposition physiology with the expectation of a satisfactory course during follow-up.

"Bay window" technique for the arterial switch operation of the transposition of the great arteries with complex coronary arteries

BACKGROUND

The success of arterial switch operations for transposition of the great arteries largely depends on faultless coronary translocation and subsequent sufficient myocardial perfusion. However, in patients with complex coronary artery anatomy, coronary translocation is often difficult to perform by conventional surgical techniques alone. Therefore we developed the "bay window" technique as a useful adjunct in patients with complex coronary arteries undergoing concomitant coronary translocation and arterial switch operation. Early and midterm results of this technique are described.

METHODS

Between September 2001 and February 2002, 4 patients with transposition of the great arteries with complex coronary arteries underwent arterial switch operation. The ages of the patients at the time of operation ranged from 8 to 52 days. Great arterial relationships were anteroposterior in 2 patients, right-oblique in 1, and side-by-side in 1. One patient also had ventricular septal defect. Coronary arterial patterns were as follows: absent left main trunk in 1 patient, short left main trunk in 1, and short right main trunk in 1. Both coronary arterial orifices were resected as a tall U-shaped cuff. The inferior half of the coronary cuff was sewn into a J-shaped incision on the pulmonary stump. The superior half of the coronary cuff was folded down inside to form a bay window channel.

RESULTS

No coronary events occurred (ie, inclusive of coronary stenosis, myocardial infarction, and coronary death). Postoperative echocardiogram demonstrated normal ventricular wall motions in all 4 patients.

CONCLUSIONS

The bay window technique is an innovative and simple surgical adjunct for translocating complex coronary arteries.

Arterial switch operation in neonates with complex congenital heart defects

The aim of the study was to analyze short-term results of the arterial switch operation in 29 neonates with simple transposition of the great arteries (group A) and 18 (group B) with complex heart defects: transposition with a ventricular septal defect (10), coarctation of the aorta (5), or Taussig-Bing anomaly (3). The operations were usually performed on the 7th day of life (2nd-30th day), after a Rashkind procedure when necessary. The mean weight was 3,530 +/- 780 g, body surface area was 0.219 +/- 0.032 m(2). Delayed sternal closure was necessary in 7 patients from group A (24%) and 8 from group B (44%) because of hemodynamic instability after weaning from extracorporeal circulation; these neonates had significantly lower body weights and smaller body surface areas. Perioperative mortality was 13.8% (4 patients) in group A and 27.8% (5 patients) in group B. Correction of complex transposition tends to be associated with a higher operative risk than simple transposition, but the difference was not significant.

Arterial switch operation with a single coronary artery

OBJECTIVE

Our purpose was to evaluate the impact of coronary pattern on survival and reintervention in patients who underwent the arterial switch operation with a single coronary artery.

METHODS

We conducted a retrospective analysis of 53 patients with a single coronary artery who underwent the arterial switch operation between 1983 and 2000 at Children's Hospital Boston. Recent follow-up information was obtained for 40 of the 46 long-term survivors (mean follow-up 7.3 +/- 4.5 years).

RESULTS

Thirty-five patients had a single right coronary artery, with the left coronary artery posterior to the pulmonary artery in 27. Eighteen patients had a single left coronary artery (16 with the right coronary artery anterior to the aorta). Six of 7 total patients who died had a single right coronary artery; all died before 1992. There were 5 early deaths, all with a single right coronary artery, with 4 deaths due to coronary malperfusion. Survivals for all patients were 91% at 6 months and 87% at 1, 5, and 10 years after the arterial switch operation. Survival figures were lower for patients having a single right ostium with the left main coronary artery posterior to the pulmonary artery compared with all other subtypes (P =.02, log-rank test). Seven patients had reintervention, 4 because of right ventricular outflow tract obstruction, 1 for heart transplantation, 1 for mitral valve repair and 1 for pacemaker implantation. Freedom from reintervention for all patients was 96% at 6 months, 92% at 1 year, 86% at 5 years, and 82% at 10 years after the arterial switch operation, with lower rates for patients having a single left ostium with the right coronary artery anterior to the aorta (P =.0003, log-rank test).

CONCLUSIONS

In the current era, the arterial switch operation with a single coronary artery can be performed safely irrespective of the coronary anatomy. Risk of reintervention is higher in patients having a single left ostium with the right coronary artery anterior to the aorta.

Should we standardise the pre-operative management of babies with complete transposition?

BACKGROUND

Complete transposition is the most common form of neonatal cyanotic heart disease. The management of this condition has changed markedly in the last decade and there appears to be a significant variation between centres in terms of pre-operative management.

OBJECTIVES/METHODS

We surveyed all paediatric cardiac surgical centres in the United Kingdom regarding pre-operative management, particularly performance and timing of balloon atrial septostomy and aortogram, imaging techniques used and discharge prior to surgery.

RESULTS

There is significant variation in pre-operative management: 10 centres now perform septostomy outside the catheter lab and 11 without general anaesthesia. Eight centres use echo control only and only 3 perform routine aortograms. Three centres do not perform routine septostomy. The most common age for arterial switch was at 1-2 weeks, but some routinely performed this procedure up to 1 month of age and others aim for arterial switch before one week of age. Only 3 centres routinely discharge patients between septostomy and switch.

CONCLUSIONS

Despite a trend towards echo guided septostomy and earlier arterial switch there is still considerable variation in early management of patients with transposition of the great arteries. Debate within the profession leading to a more standardised pre-operative management strategy would protect both the patient and the doctor involved in the care of children with complete transposition.

Single coronary artery and complete transposition of the great arteries: a technical challenge resolved?

BACKGROUND

The origin of the coronary arteries from a single aortic sinus remains a rare congenital anomaly, once regarded as having little clinical significance. Contemporary surgical practice, however, frequently demands precise coronary reimplantation. In this article we emphasize a prophylactic surgical technique found especially helpful in the repair of D-transposition of the great arteries (D-TGA)/single coronary artery.

METHODS

We reviewed the institutional cardiac registry.

RESULTS

Since 1985, 398 neonates with D-TGA were repaired with the arterial switch procedure. A mortality rate of 38% was encountered in "simple" D-TGA (n = 174)/single coronary (2.9% left facing sinus (IRLCx), 7.5% right facing sinus (IIRLCx)) and 41% in neonates with D-TGA (n = 224)/single coronary (3.6% IRLCx, 12% IIRLCx). During the past 3.5 years the surgical mortality rate of neonates (n = 6) treated with origin of the coronary arteries from a single aortic sinus has dropped to 0%.

CONCLUSIONS

The surgical repair of D-TGA/single coronary artery continues to trouble surgeons. The implantation of a well-mobilized coronary "button" into a previously anastomosed neoaorta remains a key prophylactic technique in the achievement of good technical results.

[Preoperative mortality in transposition of the great vessels]

The aim of the study was to report the incidence and causes of preoperative deaths in isolated transposition of the great vessels and to describe the clinical findings in these neonates.

PATIENTS AND METHODS

In five French centers of pediatric cardiology, data of all the neonates with isolated transposition of the great vessels who died before arterial switch operations between January 1986 and June 1996 were obtained from reviewing hospital files, echocardiography records and autopsy reports.

RESULTS

Among 199 neonates with transposition of the great vessels, 20 (9.9%) died before surgery. The death was related to intracranial haemorrhage in one premature neonate, severe and early hypoxemia in 13 full-term patients (group A) and later sudden collapse in six patients (group B). In group A, the symptoms occurred within 20 minutes after the birth and included cyanosis (n = 12), acute respiratory distress (n = 8), and shock (n = 4). Despite assisted ventilation (n = 13), bicarbonate infusion (n = 12), prostaglandin E1 (n = 7), inotropic drugs (n = 5) and balloon atrioseptostomy (n = 7), death occurred at the median age of five hours. The patent foramen ovale was absent or tiny in ten patients, normal in one patient and not specified in two patients. The ductus arteriosus was patent in ten patients and not specified in three patients. In group B, the neonates were initially in a good hemodynamic condition. Unexplained death occurred between two and five days after the birth: one infant with a large patent foramen ovale did not receive prostaglandin E1, four patients died a few hours after an angiographic study or a balloon atrioseptostomy was performed in a catheterization laboratory, and one child suffered from a cerebral anoxia due to a tightened cord.

CONCLUSION

We conclude that the high preoperative mortality rate in isolated transposition of the great vessels is mainly due to absent or small atrial shunt. These findings suggest that only prenatal diagnosis of transposition of the great vessels with immediate balloon atrioseptostomy could avoid a fatal outcome.

Direct reconstruction of the pulmonary artery during the arterial switch operation: an interesting surgical option with excellent hemodynamic results

BACKGROUND

In transposition of the great arteries, reconstruction of the neo-pulmonary artery is a challenging surgical detail during the arterial switch procedure. We present early and midterm clinical and hemodynamic results of a direct reconstruction of the pulmonary artery avoiding prosthetic and autologous material.

METHODS

Between 1990 and June 1996, a total of 189 patients underwent the arterial switch procedure because of D-transposition of the great vessels. Of them, 47 underwent direct pulmonary artery reconstruction. Mean age at operation was 5.2+/-4.1 days and mean weight was 3.75+/-0.85 kg. Simple transposition of the great arteries was present in 13, transposition of the great arteries plus ventricular septal defect in 27, and more complex forms of transposition of the great arteries in 7 patients. The great vessels were side-by-side in 4 patients and in the anteroposterior position in 43 patients. The technique of direct pulmonary reconstruction includes extensive mobilization of both pulmonary artery branches into the hilum, posterior incision of the mean pulmonary artery into the bifurcation, and resuspension of the posterior commissure of the neo-pulmonary valve. A large anastomosis without any tension is then performed, using the anterior remnant aortic sinus of Valsalva to fit out the expected size of the neo-pulmonary artery.

RESULTS

Early mortality was 8.5% (4/47) in this particular group of patients. Postoperative echocardiography was performed before hospital discharge, 3 to 6 months postoperatively, and after a mean follow-up of 24 months. Of the 43 survivors, 37 patients had a pressure gradient across the pulmonary valve of less than 15 mm Hg. Mild pulmonary stenosis (pressure gradient of 15 to 30 mm Hg) was present in 4 and more severe supravalvar stenosis (pressure gradient > 30 mm Hg) in 2 patients. After a mean follow-up of 36 months, there was one redo operation to enlarge the right ventricular outflow tract.

CONCLUSIONS

Direct reconstruction of the neo-pulmonary artery-avoiding autologous pericardium and prosthetic material-may represent an interesting option during the arterial switch operation when the great vessels lie in the anteroposterior position. This technique is simple, and the hemodynamic midterm results are very favorable. The incidence of postoperative supravalvar pulmonary stenosis is low, and there may be considerable potential for unlimited tissue growth.