Transfusion-related acute hepatic injury following postoperative platelets administration in pediatric patients undergoing the Fontan procedure

OBJECTIVE

The final common pathway of single ventricle patients is the Fontan procedure. Among the immediate postoperative complications is acute hepatic injury presented by marked elevation of liver enzymes (alanine transaminase [ALT] and aspartate transaminase [AST]). We aimed to determine the contribution of blood products transfusion to acute hepatic injury.

DESIGN

Single center retrospective cohort study.

SETTING

Pediatric Cardiac Intensive Care Unit at a tertiary medical center.

PATIENTS

Ninety-nine pediatric patients undergoing the Fontan procedure between January 2009 and December 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Out of the four types of blood products, transfusion of platelets was found to significantly affect postoperative levels of ALT and AST. Additional factors included postoperative administration of sodium bicarbonate, decreased flow through the Fontan canal and decreased urine output. Preoperative pulmonary artery pressure and pulmonary vascular resistance, cardiopulmonary bypass time, aortic cross-clamp time, amount of postoperative bleeding, and vasoactive-inotropic score did not influence liver enzymes levels CONCLUSIONS: In pediatric Fontan patients, platelets transfusions contribute to an acute hepatic injury. The relation between platelets and transfusion-related acute lung injury (TRALI) has been well described, but this is the first time it is being described in regard to acute hepatic injury (TRAHI). Changing platelet transfusion strategy could decrease morbidity in Fontan patients but further research is needed.

Pediatric Cardiac Surgery and Pain Management: After 40 Years in the Desert, Have We Reached the Promised Land?

Pain prevention in the pediatric population is mandatory and an integrative aspect of medical practice. Optimal pain management is the right of all patients and the responsibility of all health professionals. The key to adequate pain management is assessing its presence and severity, identifying those who require intervention, and appreciating treatment efficacy. The population of pediatric patients undergoing cardiac surgery is unique in both clinical severity and hemodynamic response to painful stimuli, thus making pain management even more challenging. In this review, we will describe the different pain assessment tools as well as intra- and postoperative regimens of pain management.

Estrogen-mediated downregulation of AIRE influences sexual dimorphism in autoimmune diseases

Autoimmune diseases affect 5% to 8% of the population, and females are more susceptible to these diseases than males. Here, we analyzed human thymic transcriptome and revealed sex-associated differences in the expression of tissue-specific antigens that are controlled by the autoimmune regulator (AIRE), a key factor in central tolerance. We hypothesized that the level of AIRE is linked to sexual dimorphism susceptibility to autoimmune diseases. In human and mouse thymus, females expressed less AIRE (mRNA and protein) than males after puberty. These results were confirmed in purified murine thymic epithelial cells (TECs). We also demonstrated that AIRE expression is related to sexual hormones, as male castration decreased AIRE thymic expression and estrogen receptor α-deficient mice did not show a sex disparity for AIRE expression. Moreover, estrogen treatment resulted in downregulation of AIRE expression in cultured human TECs, human thymic tissue grafted to immunodeficient mice, and murine fetal thymus organ cultures. AIRE levels in human thymus grafted in immunodeficient mice depended upon the sex of the recipient. Estrogen also upregulated the number of methylated CpG sites in the AIRE promoter. Together, our results indicate that in females, estrogen induces epigenetic changes in the AIRE gene, leading to reduced AIRE expression under a threshold that increases female susceptibility to autoimmune diseases.

Central role of interferon-beta in thymic events leading to myasthenia gravis

The thymus plays a primary role in early-onset Myasthenia Gravis (MG) mediated by anti-acetylcholine receptor (AChR) antibodies. As we recently showed an inflammatory and anti-viral signature in MG thymuses, we investigated in detail the contribution of interferon (IFN)-I and IFN-III subtypes in thymic changes associated with MG. We showed that IFN-I and IFN-III subtypes, but especially IFN-β, induced specifically α-AChR expression in thymic epithelial cells (TECs). We also demonstrated that IFN-β increased TEC death and the uptake of TEC proteins by dendritic cells. In parallel, we showed that IFN-β increased the expression of the chemokines CXCL13 and CCL21 by TECs and lymphatic endothelial cells, respectively. These two chemokines are involved in germinal center (GC) development and overexpressed in MG thymus with follicular hyperplasia. We also demonstrated that the B-cell activating factor (BAFF), which favors autoreactive B-cells, was overexpressed by TECs in MG thymus and was also induced by IFN-β in TEC cultures. Some of IFN-β effects were down-regulated when cell cultures were treated with glucocorticoids, a treatment widely used in MG patients that decreases the number of thymic GCs. Similar changes were observed in vivo. The injections of Poly(I:C) to C57BL/6 mice triggered a thymic overexpression of IFN-β and IFN-α2 associated with increased expressions of CXCL13, CCL21, BAFF, and favored the recruitment of B cells. These changes were not observed in the thymus of IFN-I receptor KO mice injected with Poly(I:C), even if IFN-β and IFN-α2 were overexpressed. Altogether, these results demonstrate that IFN-β could play a central role in thymic events leading to MG by triggering the overexpression of α-AChR probably leading to thymic DC autosensitization, the abnormal recruitment of peripheral cells and GC formation.

Effects of lack of pulsatility on pulmonary endothelial function in the Fontan circulation

OBJECTIVES

Continuous flow in the Fontan circulation results in impairment of pulmonary artery endothelial function, increased pulmonary arterial resistance, and, potentially, late failure of Fontan circulation. We investigated the mechanisms of vascular remodeling and altered vascular reactivity associated with chronic privation of pulsatility on pulmonary vasculature.

METHODS

A total of 30 pigs were evenly distributed in 3 groups: 10 underwent a sham procedure (group I) and 20 underwent a cavopulmonary shunt between the superior vena cava and right pulmonary artery--10 with complete ligation of the proximal right pulmonary artery (group II, nonpulsatile) and 10 with partial ligation (group III, micropulsatile). At 3 months postoperatively, the in vivo hemodynamics, in vitro vasomotricity (concentration response curves on pulmonary artery isolated rings), and endothelial nitric oxide synthase protein level were assessed. A comparison between group and between the right and left lung in each group was performed.

RESULTS

Group II developed right pulmonary hypertension and increased right pulmonary resistance. Endothelial function was altered in group II, as reflected by a decrease in the vasodilation response to acetylcholine and ionophoric calcium but preservation of the nonendothelial-dependent response to sodium nitroprusside. Group III micropulsatility attenuated pulmonary hypertension but did not prevent impairment of the endothelial-dependant relaxation response. Right lung Western blotting revealed decreased endothelial nitric oxide synthase in group II (0.941 ± 0.149 vs sham 1.536 ± 0.222, P = .045) that was preserved in group III (1.275 ± 0.236, P = .39).

CONCLUSIONS

In a chronic model of unilateral cavopulmonary shunt, pulsatility loss resulted in an altered endothelial-dependant vasorelaxation response of the pulmonary arteries. Micropulsatility limited the effects of pulsatility loss. These results are of importance for potential therapies against pulmonary hypertension in the nonpulsatile Fontan circulation, by retaining accessory pulmonary flow or pharmaceutical modulation of nonendothelial-dependant pulmonary vasorelaxation.

Right ventricular failure secondary to chronic overload in congenital heart disease: an experimental model for therapeutic innovation

OBJECTIVE

Mortality and morbidity related to right ventricular failure remain a problem for the long-term outcome of congenital heart diseases. Therapeutic innovation requires establishing an animal model reproducing right ventricular dysfunction secondary to chronic pressure-volume overload.

METHODS

Right ventricular tract enlargement by transvalvular patch and pulmonary artery banding were created in 2-month-old piglets (n = 6) to mimic repaired tetralogy of Fallot. Age-matched piglets were used as controls (n = 5). Right ventricular function was evaluated at baseline and 3 and 4 months of follow-up by hemodynamic parameters and electrocardiography. Right ventricular tissue remodeling was characterized using cellular electrophysiologic and histologic analyses.

RESULTS

Four months after surgery, right ventricular peak pressure increased to 75% of systemic pressure and pulmonary regurgitation significantly progressed, end-systolic and end-diastolic volumes significantly increased, and efficient ejection fraction significantly decreased compared with controls. At 3 months, the slope of the end-systolic pressure-volume relationship was significantly elevated compared with baseline and controls; a significant rightward shift of the slope, returning to the baseline value, was observed at 4 months, whereas stroke work progressed at each step and was significantly higher than in controls. Four months after surgery, QRS duration was significantly prolonged as action potential duration. Significant fibrosis and myocyte hypertrophy without myolysis and inflammation were observed in the operated group at 4 months.

CONCLUSION

Various aspects of early right ventricular remodeling were analyzed in this model. This model reproduced evolving right ventricular alterations secondary to chronic volumetric and barometric overload, as observed in repaired tetralogy of Fallot with usual sequelae, and can be used for therapeutic innovation.

Potts anastomosis for children with idiopathic pulmonary hypertension

Mortality in children with idiopathic pulmonary arterial hypertension is high, emphasizing the need for novel therapeutic approaches. A surgical approach consisting in the creation of anastomosis between descending aorta and left pulmonary artery, the Potts shunt, has been proposed to decompress right ventricle. We reported two cases of severe idiopathic pulmonary hypertension in children with right heart failure refractory to medical treatment who benefited of Potts shunt.

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.

Notch ligands potentiate IL-7-driven proliferation and survival of human thymocyte precursors

Notch and IL-7 are both well-characterized factors involved in T-cell development. In contrast to the mouse model, their precise requirements in the differentiation and/or proliferation of various stages of human thymic development have not been fully explored. Here, we demonstrate that IL-7 alone is sufficient to induce the differentiation of ex vivo purified CD34(+) triple negative (TN) surface (s) CD3(-) CD4(-)CD8(-) (CD3(-)CD4(-)CD8(-)), CD4 immature single positive (ISP) (sCD3(-)CD4(+)CD8(-)) and double positive (DP) (sCD3(-)CD4(+)CD8(+)) human thymic precursors to mature DP expressing sCD3 (sCD3(+)CD4(+)CD8(+)). We show that activation of Notch signaling by its ligands Delta-1 or Delta-4 potentiates IL-7-driven proliferation and survival of CD34(+) TN and to a lesser extent of CD4(+) ISP precursors. This effect of Notch is related to a sustained induction of IL-7 receptor alpha chain expression on thymocytes through a decreased methylation of its gene promoter. Thus, we show here that proliferation and differentiation of T-cell precursors are differentially modulated by IL-7 depending on the presence or absence of external signals. These results may have important implications for the clinical use of this cytokine as a strategy aimed at improving immune restoration.

Slide tracheoplasty in infant with congenital tracheal stenosis and tracheomalacia after esophageal atresia with tracheoesophageal fistula repair

Slide tracheoplasty can be applied successfully to all types of long segment congenital tracheal stenosis. In case of short segment tracheal stenosis, direct resection and anastomosis is often preferred. We report a case illustrating a new side benefit of the slide tracheoplasty in a patient presenting a relatively short hypoplastic tracheal segment coexisting with tracheomalacia after EA with TEF repair.

Right aortic arch and isolated left innominate artery from a left sided patent ductus arteriosus: a very rare aortic arch anomaly

Malformation of the aortic arch system has been described in details by Stewart et al. in 1964. Innominate artery originating via the ductus arteriosus from the pulmonary artery is a very rare type of congenital aortic arch anomaly that has been seldomly reported. We report the case of an aortic arch anomaly revealed by a pulmonary hypertension because of left to right shunt. Surgical procedure was performed through a median sternotomy, without cardiopulmonary bypass. After section. of the ductus arteriosus, the left innominate artery was extensively dissected and mobilized to be implanted on the left side of the ascending aorta under lateral clamping.

Aortic root abscess with coronary artery involvement: diagnostic and surgical management

We describe two cases of infectious endocarditis in infants complicated by aortic root abscess involving the coronary artery treated by the Ross operation. Multislice computed tomography was important in defining the diagnosis and in planning subsequent surgical management.

[Slide tracheoplasty in congenital tracheal stenosis]

OBJECTIVES

Slide Tracheoplasty has progressively become the gold standard in the management of long-segment tracheal stenosis in children and infants. However, in certain situations this operation might become difficult and others techniques might be preferred.

MATERIAL AND METHODS

Five patients, 1 to 6 month old had surgery by our team, for complex tracheal stenosis between 2001 and 2005. Tracheal hypoplasia was considered complex because it was associated to either: an acquired critical stenosis, a cricoid stenosis, a bronchial stenosis, a tracheal bronchus or associated to oesophageal atresia and severe tracheomalacia. All of them have been treated by a modified slide tracheoplasty.

RESULTS

The postoperative status required an average of 15 days in ICU, including 8 days of ventilation. Two patients had laryngeal nerve injury. Medium term follow up (27 months) demonstrated no need for re-intervention, good potential growth and normal child activity.

CONCLUSIONS

Slide tracheoplasty can provide good results in certain cases of severe and complex tracheal hypoplasia in infants.

Surgical management of pulmonary atresia with ventricular septal defect in late adolescence and adulthood☆

OBJECTIVE

In presence of adequate pulmonary blood flow, patients presenting with unoperated or palliated pulmonary atresia with ventricular septal defect (PA/VSD) can reach adult age. However, they remain symptomatic with a limited life expectancy.

METHODS

Since 1993, 27 patients underwent surgery for unrepaired PA/VSD. Median age was 20 (range: 15-43) years. Nineteen patients had 33 previous palliative procedures while eight were unoperated survivors. Major aortopulmonary collateral artery (MAPCA) had been observed in all but 2 and were still patent in 23. All bronchopulmonary segments were connected to the native pulmonary arteries (NPA) in 4 (type A), to both NPA and MAPCA in 18 (type B) and only to MAPCA in 5 (type C). The biventricular repair was performed in 17 patients: 3 type A, 12 type B and 2 type C. Ten patients underwent palliative procedure: eight aortopulmonary shunt, with unifocalisation in two and one right ventricle to NPA restrictive conduit.

RESULTS

One (4%) hospital death occurred following the failure of a palliative procedure. No clinical improvement was observed in seven patients including one repaired and six palliated survivors. Two late cardiac death occurred 1 and 7 years after repair. At last visit, 15 of 16 repaired survivors were in NYHA class I or II. Only one patient awaits septation, while eight other with subsequent palliation were considered not repairable.

CONCLUSION

The outcome was encouraging in patients who were eligible for completed biventricular repair. Although considered as unique alternative to cardiopulmonary transplantation, the justification for palliative surgery to improve pulmonary blood flow remains to be established.

Surgery for Transposition of the Great Arteries in Neonates Weighing Less Than 2,000 Grams: A Consecutive Series of 25 Patients

BACKGROUND

The arterial switch operation (ASO) is the optimal option for neonates with transposition of the great arteries (TGA). Low birth weight (LBW) and prematurity were considered as risk factors for poor outcome in early corrective surgery for cardiac defects. This retrospective study was undertaken to evaluate early and midterm results in infants with TGA weighing less than 2,000 grams who underwent surgical procedure in the neonatal period.

METHODS

Among the 1,505 patients who underwent surgical procedure for TGA at our institution, 25 (0.02%) had a birth weight less than 2,000 grams and constituted the study group. Median age at operation was 19 days and median weight was 1,930 grams. Prior to surgery, all were in the intensive care unit. Eleven (48%) with TGA and intact interventricular septum had an ASO but one had a Senning operation. Among 13 patients (52%) with complex TGA, 9 had anatomic repair and 4 had palliation.

RESULTS

Operative mortality was 16%. Age at operation greater than 30 days and palliation were risks factors for early death. At postoperative 43 months, actuarial survival rate was 71% and freedom from reoperation rate was 73%. All survivors were considered to have good cardiac status; 95% joined the normal curve for LBW infants without heart defects.

CONCLUSIONS

These data support that delaying repair in LBW neonates with simple or complex TGA does not confer any benefit and is associated with higher morbidity.

Heart tumors in children and adults: clinicopathological study of 59 patients from a surgical center

BACKGROUND

Heart tumors are rare lesions with variegated histological types. Their clinicopathological features could be more comprehensively categorized.

METHODS

This is a 19-year retrospective study of 17 infants/toddlers (<2 years of age) and 42 patients aged between 14 and 79 years (mean = 51.5) in a surgical center.

RESULTS

Congenital tumors (n = 17; 29%), including rhabdomyomas (n = 9), ventricular fibromas (n = 6), and hemangiomas (n = 1), required surgery mainly because of mass effect. Familial myofibromatosis was the only embolic congenital lesion. Acquired benign tumors (n = 28; 47%) included myxomas (n = 21), fibroelastomas (n = 3), myofibroblastic inflammatory tumors (n = 2), and lipomas (n = 2). Eight (29%) were revealed by systemic embolization. These benign noncongenital tumors were all treated by complete resection, except for an incompletely resected lipoma of the mitral valve. Postoperative arrhythmia (n = 1) and pericardial effusion (n = 3) were the only complications. Primary sarcomas (n = 8; 14%) were mostly vascular tumors (five of eight), and patients with high-grade tumors had a mean survival of 15 months (n = 5). Cardiac metastases (n = 6; 10%) were from carcinomas (n = 3) or sarcomas (n = 3); apart from a necrotic metastasis, all patients died (mean survival of 6 months).

CONCLUSIONS

This study shows that, regardless of patients' age, heart tumors can be classified as: (a) congenital lesions, which are spontaneously nonprogressive or regressive lesions possibly requiring surgery mainly because of mass effect; (b) acquired benign tumors, which are lesions requiring surgery often because of embolization risk; and (c) primary and secondary malignant tumors, which are lesions with globally poor prognosis but with some indications for resection.

Tracheal diaphragm: a very unusual form of congenital tracheal stenosis

A 3.2-kg newborn was intubated for neonatal respiratory distress owing to a congenital tracheal stenosis. The preoperative assessment showed a sphincter-like stenosis located 1 cm above the carina. The child was cured by resection-anastomosis through sternotomy under cardiopulmonary bypass. The pathological examination showed hypoplastic cartilage islets embedded in a fibroelastic conjunctive tissue. The posterior membranous region was preserved with the existence of smooth muscle cells. This curious malformation resembled a diaphragm at the junction between trachea and carina.

Aortic valve regurgitation after arterial switch operation for transposition of the great arteries: incidence, risk factors, and outcome

OBJECTIVES

The aims of this study were to assess the prevalence and incidence of aortic valve regurgitation (AR) after arterial switch operation (ASO), its outcome, and the risk factors.

BACKGROUND

After an ASO, the long-term fate of the aortic valve is a concern as follow-up lengthens.

METHODS

Operative and follow-up data on 1,156 hospital survivors after ASOs between 1982 and December 2000 were reviewed.

RESULTS

At last follow-up (mean duration 76.2 +/- 60.5 months), 172 patients (14.9%) had an AR. Complex transposition of the great arteries, prior pulmonary banding done in 75 patients (21 with intact ventricular septum), aortic arch anomalies, AR at discharge, older age at ASO, and aortic/pulmonary size discrepancy were associated with AR. On multivariate analysis, the presence of a ventricular septal defect (VSD) or AR at discharge multiplied the risk by 2 and 4, respectively. Freedom from AR was 77.9% and 69.5% at 10 and 15 years, respectively; hazard function for AR declined rapidly and slowly increased thereafter. Reoperation from AR was done in 16 patients with one death, valvuloplasty being unsuccessful. Freedom from reoperation for AR was 97.7% and 96.8% at 10 and 15 years, respectively; hazard function slowly increased from 2 to 16 years. Higher late mortality was not associated with AR.

CONCLUSIONS

After ASO, AR was observed and was related to VSD with attending high pressure and flow and AR at discharge. Progression of AR was slow, but incidence increased with follow-up. Reoperation for AR was rare. Late aortic valve function warrants long-term monitoring.

Surgery for right ventricle to pulmonary artery conduit obstruction: risk factors for further reoperation☆

OBJECTIVE

To identify the surgical approaches and risk factors which influence longevity of right ventricle to pulmonary artery (RV-PA) conduits following first reoperation for obstruction.

METHODS

Between January 1993 and August 2003, 114 patients underwent 141 reoperations for RV-PA conduit obstruction. Diagnoses included 'Truncus Arteriosus' (n=52), 'Pulmonary atresia/Tetralogy of fallot' (n=39), 'Double outlet right ventricle' (n=10), 'Transposition of great arteries, VSD, and pulmonary atresia' (n=9), and the 'Ross operation' (n=4). All patients had undergone a previous biventricular repair. The first reoperation for conduit obstruction was performed in 112 hospital survivors by: total conduit replacement (Group A, n=73) with valved (homograft=10 and xenograft=54) or non-valved (n=9) conduit, and patch enlargement of the obstructed RV outflow tract with preservation of the posterior and sides of the conduit wall after removing of the fibrocalcific peel and degenerated valve (Group B, n=39). Mean age at first reoperation was 8.8+/-6.7 and 7.5+/-5.3 years in patients of groups A and B, respectively. Seven patients in Group A and 18 in Group B required a second reoperation and two patients in Group B a third reoperation.

RESULTS

There were two hospital deaths and no late deaths. Mean follow-up was 5.8+/-3.2 years. Risk factors for second reoperation by univariate analysis were: homograft conduit use (P=0.004), Group B surgical approach (P=0.0001), higher RV-PA systolic pressure gradient at discharge (P=0.02), and age <5-years-old (P=0.01). Multivariate analysis showed that inclusion in Group B and younger age (<5-years-old) at repair were independent risk factors for second reoperation. Group B surgical approaches had higher RV-PA systolic pressure gradient at discharge (P=0.02) and required more PA bifurcation repair at the time of second reoperation (P=0.05). Freedom from second reoperation for conduit obstruction was significantly higher in Group A patients at 5 and 8 years (P<0.04) and those with xenografts rather than homograft (P=0.04).

CONCLUSIONS

Our results support the optimal surgical approach for RV-PA conduit obstruction is total replacement with a xenograft. RV outflow reconstruction by other techniques without complete dissection of PA bifurcation does not completely relieve the stenosis and could cause early restenosis. Higher systolic gradients at discharge and younger age at first reoperation are predictors of earlier reoperation.

Repair of recurrent coarctation using an ascending aortic autograft

Results of aortic arch repair for interrupted aortic arch or aortic coarctation have considerably improved. However, re-stenosis or aneurysm formation is a common complication requiring complex re-interventions or even extra-anatomic bypass grafting. In two patients with recurrent coarctation, the use of cardiopulmonary bypass was mandatory, in one due to the concomitant repair of the intra-cardiac defect, in the other due to the small aortic arch, the long segment aortic coarctation and the small diameter of the supra-aortic vessels. In both patients a segment of the ascending aorta was interposed between the distal aortic arch and the proximal descending aorta with uneventful postoperative courses and freedom from pathological findings at 1 year and 6 months follow-up. In patients undergoing complex congenital heart surgery involving the ascending aorta, a segment of the autologous ascending aorta may be used to repair recurrent isthmic stenosis, avoiding the use of any foreign material.

[Cardiac failure in children]

The understanding of cardiac failure pathophysiology in children has advanced greatly in recent years. Whilst cardiac failure secondary to left ventricular dysfunction with viral or metabolic cardiomyopathy is comparable in pathophysiological terms with adults, other aetiological mechanisms are also implicated, linked both to anatomical anomalies in congenital cardiopathy and their surgical repair. The role of the neuroendocrine system with adrenergic activation of the renin-angiotensin system, secretion of natriuretic peptides and the inflammatory system, before and during surgical repair procedures, have been proven both experimentally and clinically. Understanding these pathophysiological mechanisms opens new therapeutic perspectives for improving the management of children with congenital cardiopathy in cardiac failure and reducing postoperative mortality and morbidity.

Preoperative and postoperative evaluation of airways compression in pediatric patients with 3-dimensional multislice computed tomographic scanning: Effect on surgical management

OBJECTIVES

Surgical management of airway compression of vascular origin requires an accurate analysis of anatomy and various mechanisms of compression. This study assessed the usefulness of 3-dimensional computed tomographic scanning in the preoperative and postoperative evaluation of airways compression in a pediatric population.

METHODS

Thirty-seven consecutive patients (median age, 4 months) were examined with multislice 3-dimensional computed tomographic scanning: 18 patients before surgical treatment of anomalies of vascular rings, 2 patients because of respiratory symptoms after repair of esophageal atresia, and 17 patients because of persisting respiratory symptoms or prolonged mechanical ventilation after cardiac surgery for congenital heart disease.

RESULTS

The procedure was successful, with high-quality diagnostic imaging obtained in all cases without any complications. The anatomy and relationship between the vascular arches and airways was analyzed in all referred patients with vascular arch anomalies confirmed on the basis of the surgical findings, and this helped the surgeon to plan the procedure and choose the best approach. After cardiac surgery, the airway and vascular structures involved and the mechanism of compression were specified in all but one case, and the 3-dimensional computed tomographic scan serves as an important tool for deciding whether to perform reoperation on patients requiring prolonged mechanical ventilation.

CONCLUSION

Three-dimensional computed tomographic scanning is a safe, fast, and noninvasive method useful for accurately analyzing the mechanisms of airway compression of vascular origin and thus possible improving the surgical management of pediatric patients.

[Surgical repair of atrial septal defect in 1011 consecutive patients]

The immediate postoperative complications of 1011 consecutive patients undergoing surgical repair of atrial septal defects between 1980 and 1998 at Marie Lannelongue Hospital were analysedwith the ultimate objective of comparing their incidence with that of percutaneous closure. Five patients died (0.49%) of low cardiac output (N=3), pulmonary oedema (N=1) or pulmonary hypertension (N=1). A total of 356 patients (35.2%) had 448 postoperative complications. There were 77% minor and 23% major complications. The minor complications included arrhythmias and conduction defects (N=130), respiratory complications (N=90) and pericardial effusions (N=64). The main major complications were cardiac failure (N=27), cardiac tamponade (N=13), neurological complications (N=8) and reoperation (N=28). Of the survivors, 95.6% of patients were discharged from hospital with no residual problem and 41 (4.4%) had sequellae: arrhythmias (N=29, including one pacemaker implantation), neurological complications (N=4), acquired mitral regurgitation (N=2), phrenic nerve paralysis (N=1) and minimal residual shunt (N=10). Factors correlated with surgical morbidity were age, the severity of pulmonary hypertension, the type of atrial septal defect (less morbidity with ostium secundum defects), the presence of associated malformations, the surgical approach (less morbidity with the right postero-lateral thoracic approach). This study demonstrated the incompressible risk of open heart cardiac surgery. It will form a basis for a comparative study of the two modern methods of treating atrial septal defect: surgical and percutaneous closure.

Additional Pulmonary Blood Flow Has No Adverse Effect on Outcome After Bidirectional Cavopulmonary Anastomosis

BACKGROUND

Controversy continues over whether additional sources of pulmonary blood flow are beneficial in combination with a bidirectional cavopulmonary anastomosis. We have therefore assessed the effects of additional pulmonary blood flow on outcome after bidirectional cavopulmonary anastomosis.

METHODS

From 1996 to 2000, 106 patients underwent bidirectional cavopulmonary anastomosis, either isolated (group 1, n = 54), or with additional pulmonary blood flow through the pulmonary artery (group 2, n = 30) or a Blalock-Taussig shunt (group 3, n = 22).

RESULTS

Superior vena cava syndrome was more frequent in group 2 and less in groups 1 and 3 (p < 0.05). Low-output syndrome was more frequent in group 2 and less in group 3 (p = 0.01). Repeated-measures analysis of variance showed higher oxygen saturations with additional pulmonary blood flow (p < 0.05) and significant changes over time (p < 0.0001). Pulmonary pressures, systemic ventricular fractional shortening, end-diastolic diameter index, end-diastolic pressure, and atrioventricular valve regurgitation remained unaffected by additional pulmonary blood flow. Pulmonary artery pressures were lower in group 2 than 3 (p < 0.05). Fractional shortening (p < 0.05) and atrioventricular valve regurgitation (p < 0.0001) changed significantly over time. Fractional shortening showed a strong trend toward different changing patterns with or without additional pulmonary blood flow (p = 0.055), and atrioventricular valve regurgitation showed different changing patterns among the groups (p < 0.005). End-diastolic diameter and pulmonary artery dimensions, which were smaller than normal, remained unchanged. In logistic regression, smaller body surface area at bidirectional cavopulmonary anastomosis, single ventricle, and bidirectional cavopulmonary anastomosis with a Blalock-Taussig shunt were associated with early death. Actuarial survival including total cavopulmonary connection did not differ among groups (p = 0.96).

CONCLUSIONS

We conclude that additional pulmonary blood flow has no adverse effect on outcome after cavopulmonary anastomosis. Additional flow through the main pulmonary artery offers different advantages and disadvantages concerning perioperative complications and pulmonary artery growth compared with additional flow through a Blalock-Taussig shunt.

Additional Pulmonary Blood Flow Has No Adverse Effect on Outcome After TCPC

BACKGROUND

Use of additional sources of pulmonary blood flow (APBF) with bidirectional cavopulmonary anastomosis (BDG) and total cavopulmonary connection (TCPC) remains controversial. We have therefore assessed the effects of APBF on BDG and TCPC outcome.

METHODS

From 1996 to 2000, 106 patients underwent BDG, either isolated (group 1, n = 54), or with APBF via pulmonary artery (PA) (group 2, n = 30), or Blalock-Taussig shunt (BTS) (group 3, n = 22) with 28 patients completed by TCPC.

RESULTS

After BDG low output syndrome was more frequent in group 2 and less in 3 ( p = 0.01), whereas superior cava syndrome was again more common in group 2 and less in groups 1 and 3 ( p < 0.05) than expected. Mortality and complications were similar after TCPC in all groups. Oxygen saturation (SaO (2)) was lower without than with APBF ( p < 0.002) after BDG and in group 3 than in group 2 after TCPC ( p < 0.05). Repeated measures ANOVA showed no effect of APBF on SaO (2), PA pressures, fractional shortening, end-diastolic pressure and AV-valve function.

CONCLUSIONS

Early after BDG, APBF via PA presents different difficulties than APBF via BTS. However, BDG and TCPC outcomes are not affected by the presence or absence of APBF.

Left-sided lesions after anatomic repair of transposition of the great arteries, ventricular septal defect, and coarctation: Surgical factors

OBJECTIVE

This study was undertaken to identify potential anatomic and surgical factors creating left-sided lesions, namely recoarctation of the aorta and neoaortic regurgitation, after anatomic repair of transposition of the great arteries with ventricular septal defect and aortic coarctation.

METHODS

From 1983 to September 2002, 109 survivors out of 120 patients were studied. Two-stage repair was performed in 42 patients (group A), and single-stage repair was performed in 67 (groups B and C). Before repair, the diameters of the ascending aorta and main pulmonary artery were measured. In the patients with single-stage repair, coarctation was repaired by extended end-to-end anastomosis in 35 patients (group B) and by pulmonary homograft patch augmentation in 32 patients (group C). The ventricular septal defect was closed through the pulmonary artery in 70 patients and through the right ventricle or atrium in 39 patients. The neoaorto-aortic discrepancy was treated by V-shaped resection of the posterior sinus of Valsalva in 7 cases, pulmonary homograft patch in 32 cases, and anterior splitting of the ascending aorta in all cases. Before discharge from the hospital, neoaortic root and ascending aorta diameters and aortic regurgitation grade were recorded. Neoaortic regurgitation progression and reintervention were the end points of follow-up (97.2 +/- 61.2 months).

RESULTS

Early and late survivals were significantly better in group C (P <.001). Risk factors for neoaortic regurgitation at discharge by univariate analysis were single-stage repair (P <.05) and ventricular septal defect closure through the pulmonary artery (P =.0076). On multivariate analysis, the latter was the only risk factor for neoaortic regurgitation at discharge and at last follow-up. Multivariate analysis showed that higher neoaortic root/ascending aorta ratio and ventricular septal defect closure through the pulmonary artery were risk factors for neoaortic regurgitation evolution at last follow-up. There were 29 reinterventions, 19 for recoarctation of the aorta and 10 for neoaortic regurgitation with or without aortic root dilatation. Group B (P <.05), high neoaortic root/ascending aorta ratio (P <.01), and progressive neoaortic regurgitation (P <.05) were risk factors for recoarctation of the aorta. Group A was a risk factor for aortic valve replacement at 10 years (P <.05).

CONCLUSION

Neonatal single-stage repair with pulmonary homograft aortic augmentation remains the optimal approach to transposition of the great arteries with ventricular septal defect and aortic coarctation. It provides better early and late survivals and freedoms from left-sided lesions. Avoidance of late recoarctation of the aorta and progressive neoaortic regurgitation requires meticulous closure of the ventricular septal defect and evenly sized reconstruction of the aorta from root to distal arch.

[A rare form of aortic arch anomaly: left aortic and right descending aortic arch]

Among aortic arch anomalies, the circumflex aortic variety, involving left aortic and right descending aortic arch, is a rare situation. Two children were recently sent to the CCML for signs of tracheobronchial compression leading to the discovery of this anomaly. The younger child, aged 2 months, had been intubated since birth, and angiography presented a constrictive form of the disorder due to the presence of a small arterial canal linking the pulmonary tree to an aberrant right subclavian artery arising from a voluminous Kommerel diverticulum. Removal of the obstacle was achieved by section of the arterial channel approached via a right posterior thoracotomy. The second patient, aged 7 years, had chronic bronchopneumonia with severe obstructive syndrome. Multislice CT investigation with three-dimensional reconstruction showed obstruction at two levels: the first concerned the lower part of the trachea related to the posterior transverse segment of the aortic arch; the more severe second obstruction was due to a vascular pinch formed by the descending aorta and the right pulmonary artery. Improvement in functional signs with time reported by the parents had led to temporisation in this case. In adults this anomaly is often a fortuitous finding during radiological investigations performed for slight functional signs. In all cases of aortic anomalies and associated lesions, the importance of precise and thorough investigation using modern radiological techniques must be stressed.

Is surgical intervention still indicated in recurrent aortic arch obstruction?

BACKGROUND

Introduction of balloon dilatation has become the standard treatment for recurrent aortic arch obstruction and has changed the therapeutic approach to patients with this disorder.

OBJECTIVES

Whether all patients with recurrent aortic arch obstruction are candidates for balloon dilatation remains unanswered. In addition, only few reports have tried to compare the results between patients undergoing balloon dilatation or redo operations.

METHODS

Since 1983, 97 patients underwent reintervention for recurrent aortic arch obstruction (42 dilations and 55 reoperations). Eight had immediate unsuccessful dilatation and were shifted to the surgical group (n = 63). The median age at reintervention was 21.7 months (10 days-45 years), and the median delay was 13.6 months (7 days-17 years). Anatomy of the aortic arch oriented the surgical approach to treat arch hypoplasia. It could be performed through a left thoracotomy in 52 patients, with extended end-to-end anastomosis in 34 patients, subclavian flap repair in 9 patients, conduit insertion in 6 patients, and patch enlargement in 3 patients. More recently, an anterior approach with cardiopulmonary bypass without circulatory arrest was applied to enlarge the patch in all the aortic arches.

RESULTS

There was one early death in the surgical intervention group and 2 late deaths in the dilation group. Major complications and recurrence were higher in the dilated group (4 vs 0, P <.01, and 14 vs 5, P <.0004, respectively). At a mean follow-up of 11.8 +/- 4.1 years in the surgical intervention group and 7.5 +/- 2.5 years in the dilated group, systemic hypertension was normalized in all but 5 patients in the surgical intervention group and 6 patients in the dilated group.

CONCLUSION

Reoperation for recurrent aortic arch obstruction can be performed safely, with low rates of mortality and morbidity. This approach should be considered versus balloon angioplasty, especially in patients older than 4 years and in the presence of aortic arch hypoplasia.

Induction of pulmonary angiogenesis by adenoviral-mediated gene transfer of vascular endothelial growth factor

BACKGROUND

We hypothesized that gene transfer of vascular endothelial growth factor (VEGF) mediated by an adenovirus vector might induce pulmonary artery angiogenesis in a lamb model of pulmonary artery hypoplasia.

METHODS

Thirteen fetal lambs had left pulmonary artery banding at 106 days of gestation. Following birth, 3 groups were divided: VEGF group (n = 5) and beta-GAL group (n = 4) received an adenoviral vector encoding respectively for human VEGF165 and for galactosidase A. A control group (n = 4) had neither gene nor virus. Viral suspensions were selectively instilled in the left bronchus 6.5 days after birth. Five nonoperated lambs constituted the normal group. Euthanasia was performed at 30 days of age. Gene transfer was confirmed by blue coloration of left lung obtained with Xgal solution in an additional experiment. Histomorphometric evaluation was performed. All groups were compared with ANOVA test and paired test was used to compare right and left lung in each animal.

RESULTS

Left lung was similarly hypoplastic in all operated lambs. Left pulmonary artery hypoplasia present in all operated groups was significantly less pronounced in VEGF group. The number of pleural arteries was similarly increased in left lung of all operated lambs. Left lung arterial density was higher in VEGF group than in all other groups. The percentage of parenchyma of left lung was lower in beta-GAL group than in all others, partially returned to normal in VEGF group.

CONCLUSIONS

In this model, transbronchial VEGF gene transfer induces pulmonary angiogenesis, proximal pulmonary artery growth and contributes to lung parenchyma recovery.