Are Blood Products Routinely Required in Pediatric Heart Surgery?

A restrictive blood transfusion strategy has emerged in adult cardiac surgery. However, the feasibility in children is poorly investigated. 352 consecutive patients undergoing open-heart surgery were retrospectively reviewed, excluding patients requiring extracorporeal membrane oxygenation. Patient demographics, perioperative blood product usage, and clinical outcome parameters were investigated. Variables predicting the need for blood products were delineated. Of the 352 study patients, 148 patients (42%) underwent bloodless surgery and 204 (58%) were transfused. Of the 204 transfused patients, 170 (83.4%) patients received one blood transfusion and 34 (16.6%) received two or more blood transfusions. Patient's weight and preoperative hematocrit (Hct) were statistically significant in predicting the need for blood priming the CPB circuit (AUC 0.99, p < 0.001, sensitivity 96.6%, specificity 95.2%). A body weight of 8.5 kg carried a sensitivity of 100% and specificity of 94.5% (p < 0.001) for a blood prime. Among patients with a weight less than 8.5 kg (n = 171), only 27 patients (15.8%, p < 0.001) required additional transfusion of PRBCs. Factors impacting the need for a blood transfusion during CPB included redo surgery [odds ratio (OR) 4.61, p = 0.001] and the highest lactate level on CPB (OR 1.65, p = 0.006). Redo surgery had the highest impact (OR 7.27, p = 0.012) for requiring a postoperative PRBC transfusion. A restrictive transfusion strategy can be safely implemented in pediatric cardiac surgery. The majority of children with a BW > 8.5 kg required no blood products and those with a BW ≤ 8.5 kg required only 1 unit of blood, to prime the cardiopulmonary bypass circuit.

Hybrid stenting for left ventricular outflow tract obstruction in congenitally corrected transposition of the great arteries.

Congenitally corrected transposition of the great arteries is commonly associated with left ventricular outflow tract obstruction. We describe a case of congenitally corrected transposition of the great arteries and previous surgical ventricular septal defect repair with recurrent left ventricular outflow tract obstruction. The patient underwent a hybrid procedure to stent the left ventricular outflow tract, which was successful with no re-intervention through 3 years of follow-up.

Nonuniform and variable arrangements of ryanodine receptors within mammalian ventricular couplons.

RATIONALE: Single-tilt tomograms of the dyads in rat ventricular myocytes indicated that type 2 ryanodine receptors (RYR2s) were not positioned in a well-ordered array. Furthermore, the orientation and packing strategy of purified type 1 ryanodine receptors in lipid bilayers is determined by the free Mg2+ concentration. These observations led us to test the hypothesis that RYR2s within the mammalian dyad have multiple and complex arrangements. OBJECTIVES: To determine the arrangement of RYR2 tetramers in the dyads of mammalian cardiomyocytes and the effects of physiologically and pathologically relevant factors on this arrangement. METHODS AND RESULTS: We used dual-tilt electron tomography to produce en-face views of dyads, enabling a direct examination of RYR2 distribution and arrangement. Rat hearts fixed in situ; isolated rat cardiomyocytes permeabilized, incubated with 1 mmol/L Mg2+, and then fixed; and sections of human ventricle, all showed that the tetramer packing within a dyad was nonuniform containing a mix of checkerboard and side-by-side arrangements, as well as isolated tetramers. Both phosphorylation and 0.1 mmol/L Mg2+ moved the tetramers into a predominantly checkerboard configuration, whereas the 4 mmol/L Mg2+ induced a dense side-by-side arrangement. These changes occurred within 10 minutes of application of the stimuli. CONCLUSIONS: The arrangement of RYR2 tetramers within the mammalian dyad is neither uniform nor static. We hypothesize that this is characteristic of the dyad in vivo and may provide a mechanism for modulating the open probabilities of the individual tetramers.

Coronary artery augmentation with the right subclavian artery for single coronary artery variants of dextro transposition of the great arteries treated by an arterial switch operation.

Objective: Single coronary artery variants in dextro transposition of the great arteries increase the technical demands of performing coronary translocations during the arterial switch operation (ASO). Coronary augmentation using the right subclavian artery as an interposition graft is a viable option in certain cases. The aim of this study is to describe this operative technique and review outcomes. Methods: Of 59 patients who underwent an ASO, from July 2015 to May 2021, 6 had single coronary variants in which the right subclavian artery was used as an interposition graft. Mean follow-up was 21.5 months. Results: Patients mean age and weight at the time of surgery were 7.1 ± 3.8 days and 2.84 ± 0.76 kg, respectively. Four patients had the left anterior descending coronary artery and right coronary artery coming from the left sinus and the circumflex coronary artery coming from the right sinus. One patient had a single ostium arising from the left sinus and another patient had a single ostium coming from the right sinus. All patients are alive and free of cardiac symptoms at follow-up. Conclusions: Single coronary artery variants in dextro transposition of the great arteries can pose technical challenges for coronary translocation during ASO. The augmentation of coronary buttons using a segment of the right subclavian artery is an option which should be considered in selective cases.

Preoperative Evaluation of Refugee Children With Heart Disease.

The objective of this report is to identify nutritional deficiencies and health concerns in Canadian paediatric refugee patients with heart disease before cardiac surgery. A retrospective case study was conducted with 4 refugee children, aged 0-18 years, with heart disease referred to Cardiac Surgery. A total of 75% of patients had low vitamin D levels, 50% had selenium deficiency, 50% had iron deficiency anaemia, 75% were below the third percentile for height and weight for age, and 75% had dental caries. Early laboratory, nutritional, and dental screening of paediatric refugee patients at the time of heart disease diagnosis can optimize general and cardiovascular health before surgical intervention.

Notre étude visait à dépister des carences nutritionnelles et des problèmes de santé présents chez les enfants réfugiés au Canada atteints de cardiopathie, avant une intervention chirurgicale cardiaque. Une étude de cas rétrospective a été menée auprès de quatre enfants réfugiés, âgés de 0 à 18 ans, souffrant de cardiopathie et orientés vers la chirurgie cardiaque. Au total, 75 % des patients présentaient un faible taux de vitamine D, 50 % avaient une carence en sélénium, 50 % souffraient d'anémie ferriprive, 75 % avaient une taille et un poids inférieurs au troisième percentile pour leur âge et 75 % présentaient des caries dentaires. Un dépistage précoce comprenant des analyses de laboratoire, une évaluation nutritionnelle et un examen dentaire, au moment d'un diagnostic de cardiopathie chez les enfants réfugiés, pourrait permettre d'améliorer leur état de santé général et cardiovasculaire avant une intervention chirurgicale.

Hybridizing the hybrid: a "serendipitous bridge" to heart transplantation in a child with hypoplastic left heart syndrome.

We report a unique experience with stage 1 palliation of hypoplastic left heart syndrome (HLHS) using the hybrid approach. The tortuous anatomy of the ductus arteriosus precluded stenting. Persistent ductal patency and ability to support the systemic circulation adequately after prolonged prostaglandin E1 (PGE1) infusion and its subsequent discontinuation presented us with a novel approach to hybrid palliation of hypoplastic left heart syndrome. Our experience offers a tempting approach, but it should not be considered a standard alternative management option to stage I hybrid palliation based on a single case report. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12055-020-01088-8.

Tricuspid Intervention Following Pulmonary Valve Replacement in Adults With Congenital Heart Disease.

BACKGROUND: Tricuspid regurgitation (TR) is common among adults with corrected tetralogy of Fallot (TOF) or pulmonary stenosis (PS) referred for pulmonary valve replacement (PVR). Yet, combined valve surgery remains controversial. OBJECTIVES: This study sought to evaluate the impact of concomitant tricuspid valve intervention (TVI) on post-operative TR, length of hospital stay, and on a composite endpoint consisting of 7 early adverse events (death, reintervention, cardiac electronic device implantation, infection, thromboembolic event, hemodialysis, and readmission). METHODS: The national Canadian cohort enrolled 542 patients with TOF or PS and mild to severe TR who underwent isolated PVR (66.8%) or PVR+TVI (33.2%). Outcomes were abstracted from charts and compared between groups using multivariable logistic and negative binomial regression. RESULTS: Median age at reintervention was 35.3 years. Regardless of surgery type, TR decreased by at least 1 echocardiographic grade in 35.4%, 66.9%, and 92.8% of patients with pre-operative mild, moderate, and severe insufficiency. In multivariable analyses, PVR+TVI was associated with an additional 2.3-fold reduction in TR grade (odds ratio [OR]: 0.44; 95% confidence interval [CI]: 0.25 to 0.77) without an increase in early adverse events (OR: 0.85; 95% CI: 0.46 to 1.57) or hospitalization time (incidence rate ratio: 1.17; 95% CI: 0.93 to 1.46). Pre-operative TR severity and presence of transvalvular leads independently predicted post-operative TR. In contrast, early adverse events were strongly associated with atrial tachyarrhythmia, extracardiac arteriopathy, and a high body mass index. CONCLUSIONS: In patients with TOF or PS and significant TR, concomitant TVI is safe and results in better early tricuspid valve competence than isolated PVR.

Biventricular assist devices as a bridge to heart transplantation in small children.

BACKGROUND: Experience with the use of biventricular assist device (BiVAD) support to bridge small children to heart transplantation is limited. METHODS AND RESULTS: We used BIVAD support (Berlin EXCOR) in 9 pediatric heart transplant candidates from 4/05 to 7/07. The median patient age was 1.7 years (12 days to 17 years). The median patient weight was 9.4 kg (3 to 38 kg). All children were supported with multiple intravenous inotropes+/-mechanical ventilation (6) or ECMO (3) before BiVAD implantation. All had significant right ventricular dysfunction. The median pulmonary vascular resistance index (Rpi) was 6.0 WU/m(2). Eight patients were successfully bridged to heart transplantation after a median duration of BiVAD support of 35 days (1 to 77 days). One death occurred after 10 days of support from perioperative renal failure in a 3 kg infant. Five patients required at least 1 blood pump change. One patient had a driveline infection requiring treatment. There were no acute neurological complications, no thromboembolic events, and no bleeding complications. In 2 patients with Rpi >10 WU/m(2) unresponsive to pulmonary vasodilator therapy, Rpi dropped to 1.4 and 4.6 WU/m(2), after 33 and 41 days of support, respectively. All 8 survivors underwent successful heart transplantation. Of 5 patients supported >30 days, 3 developed an extremely elevated (>90%) panel reactive antibody by ELISA that was not confirmed by other methods; none had a positive donor-specific retrospective crossmatch. There was 1 episode of rejection (with hemodynamic compromise) in the 8 transplanted patients. Rpi was normal (<3 WU/m(2)) without pulmonary vasodilators in all patients within 3 months after transplant. There have been no deaths after transplant with a median follow-up of 19 months. CONCLUSIONS: BiVAD support can effectively be used in small children as a bridge to heart transplantation and can be accomplished with low mortality and morbidity. BiVAD support may offer an additional means to reverse extremely elevated pulmonary vascular resistance. Surveillance for HLA antibody sensitization during BiVAD support may be complicated by the development of non-HLA antibodies which may not reflect true HLA presensitization.

Current treatment of aortopulmonary window.

Aortopulmonary window is a rare abnormal congenital communication between the pulmonary artery and the ascending aorta with intact aortic and pulmonary valves. Because pulmonary hypertension and premature death are the natural history of the uncorrected left-to-right shunt physiology that occurs with aortopulmonary window, surgical correction, which is the gold standard of treatment, should be offered to patients at the time of diagnosis, before the development of lung injury and irreversible pulmonary hypertension.

Infectious, malignant, and autoimmune complications in pediatric heart transplant recipients.

OBJECTIVE: To review clinical courses of pediatric heart transplant survivors after 5 years from transplantation for infections, lymphoproliferative, and autoimmune diseases. STUDY DESIGN: A total of 71 patients were examined in 2 groups, infant recipients (underwent transplant <1 year of age, n = 38) and older recipients (underwent transplant >1 year, n = 33). All patients received comparable immunosuppression. Calculated occurrence rates were reported as means per 10 years of follow-up with SEs. Differences were examined by using Poisson regression. RESULTS: Infant recipients had significantly higher (P < .001) occurrence rates of severe (mean, 2.04 +/- 0.5) and chronic infections (mean, 4.58 +/- 0.67) compared with older recipients (means, 0.37 +/- 0.19 and 1.87 +/- 0.70, respectively). Types of infections were similar to those in the general population with extremely rare opportunistic infections; however, they were more severe and resistant to treatment. Autoimmune disorders occurred at a frequency comparable with lymphoproliferative diseases and were observed in 7 of 38 infants (18%). Most common were autoimmune cytopenias. CONCLUSIONS: Infant heart transplant recipients who survive in the long term have higher occurrence rates of infections compared with older recipients. Autoimmune disorders are a previously unrecognized morbidity in pediatric heart transplantation.

Aortic Arch Homograft Reconstruction of Nonconfluent Pulmonary Arteries During Extracardiac Fontan.

Reconstruction of nonconfluent pulmonary arteries during Fontan completion is a challenging technical issue. In this case report, we describe the use of an aortic homograft, including the aortic arch, to complete a Fontan and reconstruct the pulmonary artery confluence in a child with discontinuous pulmonary arteries and bilateral superior caval veins who had undergone bilateral unidirectional Glenn palliation. The configuration of the aortic homograft was ideal to ensure laminar flow from the inferior vena cava to both pulmonary arteries and in maintaining durable elastance posterior to the native aorta.

Jellyfish-Like Accessory Mitral Valve Tissue Causing Near-Collapse in a Young Child.

Accessory mitral valve tissue (AMVT) causing left ventricular outflow tract obstruction (LVOTO) is rare. We report a case of AMVT causing severe LVOTO resulting in acutely progressive symptoms of near-collapse. Urgent surgical resection eliminated the patient's life-threatening symptoms. AMVT should be considered among potential LVOTO diagnoses, and early surgical intervention may be required.

Impact of TGFbeta1 gene polymorphisms on late renal function in pediatric heart transplantation.

Late renal dysfunction may affect long-term outcome of nonrenal transplant recipients. We hypothesized that transforming growth factor beta1 (TGFbeta1) might play a role in the fibrogenic mechanisms leading to renal dysfunction. The aim was to determine whether TGFbeta1 gene polymorphisms are associated with renal outcome in pediatric heart recipients. Eighty-eight patients underwent a first heart transplantation at the age of 7.1 +/- 6.5 years, received tacrolimus-based immunosuppression, and were followed for > or =1 year (6.7 +/- 3.2 years). Creatinine clearance (CrCl; ml/mn/1.73 m2) was calculated (Schwartz) before transplant, then at 1 month, 6 months, and 1 year, and yearly up to 7 years. Impaired function was defined as CrCl <80 ml/mn/1.73 m2. Mean CrCl decreased from 120 +/- 53 ml/mn/1.73 m2 before transplant to 98 +/- 40, 96 +/- 37, 102 +/- 30, and 101 +/- 38 ml/mn/1.73 m2 at, respectively, 6 months and 1, 5 (n = 58), and 7 years (n = 33). The TGFbeta1 high-producer genotype had worse CrCl than intermediate and low producers at every time point, despite similar pretransplant CrCl (pretransplant = 120 +/- 53 vs 118 +/- 55 ml/mn/1.73 m2 [p = 0.8], 1 year = 92 +/- 38 vs 113 +/- 30 ml/mn/1.73 m2 [p = 0.03]) and similar tacrolimus levels. The TGFbeta1 high-producer genotype was associated with CrCl < 80 ml/mn/1.73 m2. The TGFbeta1 high-producer genotype is associated with renal dysfunction in pediatric heart recipients.

Impact of ELISA-detected anti-HLA antibodies on pediatric cardiac allograft outcome.

In this study, we determine whether the presence of enzyme-linked immunosorbent assay (ELISA) detected anti-human leukocyte antigen (HLA) antibodies correlates with acute and chronic rejection in pediatric heart transplantation (Tx). Forty-five patients, who had serial ELISA pre- and posttransplantation, were studied. Age at Tx was 8.2 +/- 7.2 years. Acute rejection (AR) was defined as International Society for Heart and Lung Transplantation Grade > or =3a. Patients were defined as rejectors (22 cases) if they had recurrent AR or steroid-resistant AR within the first year post-Tx; the other cases (23) were defined as nonrejectors. Overall, 219 samples were analyzed. Twenty-two of the 45 had pre- or post-Tx anti-HLA antibodies: 77% in rejectors (17/22) and only 22% in nonrejectors (5/23), p = 0.0002. Pre-Tx HLA antibodies were present in 12 cases (27%). Presensitization was more frequent in rejectors (11/22, 50%) than in nonrejectors (1/23, 4%, p = 0.0005). Nineteen cases retained (9 cases) or developed (10 cases) anti-HLA antibodies post-Tx: 14 in rejectors (63.6%) and 5 in nonrejectors (21.7%), p = 0.003. Four of eight cases with coronary artery disease (50%) had preformed anti-HLA antibodies compared with 8 of 37 without coronary artery disease (25.6%) (p = 0.09). Preformed, persistent, and de novo ELISA-detected anti-HLA antibodies were correlated with first-year acute rejection profile.

Pulsatile paracorporeal assist devices in children and adolescents with biventricular failure.

Children with heart failure unresponsive to medical therapy are left with few options for survival. Pulsatile paracorporeal ventricular assist devices are life-saving options for such patients, allowing for bridge to transplantation or cardiac recovery. From March 1997 to July 2004, 12 patients underwent implantation of Thoratec biventricular assist devices (BVADs) for refractory heart failure. Mean age was 14.9 (range 7-20) and mean BSA was 1.7 (range 1.1-1.9). Indications for support included end-stage cardiomyopathy (n=10), myocarditis (n=1), and postcardiotomy heart failure (n=1). Preimplant variables included 50% of patients requiring mechanical ventilation (mean 4.2 days), hyperbilirubinemia in 58%, and acute renal failure in 50%. Mean duration of support was 64.5 (range 2-175) days. Overall survival was 83%, with nine patients successfully bridged to transplantation (75%). One patient exhibited recovery allowing for device explantation, and two patients died while on BVADs. Complications included bleeding requiring reoperation in 25% (n=3), stroke in 8% (n=1), driveline infections in 17% (n=2), and device malfunction in one patient. Pulsatile paracorporeal BVADs can be used successfully in children and adolescents with heart failure. These results warrant consideration of using available miniaturized technology in the United States for the support of smaller children with intractable biventricular failure.

Case report of combined pediatric heart-lung-liver transplantation.

We present the youngest successful patient with combined heart-lung-liver transplantation. The patient was a 2.5-year-old child with Alagille syndrome suffering from tetralogy of Fallot with pulmonary atresia and multiple aortopulmonary collaterals and familial cholestasis.

Successful late reintervention after the arterial switch procedure.

BACKGROUND: The arterial switch operation is the therapy of choice for transposition of the great arteries. METHODS: A retrospective analysis of all children undergoing the arterial switch operation between November 1985 and October 2000 was conducted, highlighting the frequency and nature of late invasive reintervention. RESULTS: One hundred forty-four children were operated on. Operative survival was 89% (128 of 144). Late reintervention was required in 23% (29 of 128) of survivors. Neopulmonary stenosis (PS) was the most common complication requiring treatment, occurring in 16% (21 of 128) of patients. Eleven of 21 patients with PS required reoperation, whereas 10 were managed with percutaneous techniques. Other indications for reintervention included aortic arch obstruction (3 patients), ventricular septal defect (with PS in 2 patients), bronchial stenosis (2 patients), coronary stenosis (2 patients), aortic stenosis (with PS in 1 patient), and residual atrial septal defect (1 patient). There has been no mortality or major morbidity in those children who have undergone reintervention. CONCLUSIONS: Invasive reintervention after the arterial switch operation is occasionally required. The most common indication is PS. Reintervention is well tolerated by those children who require it. Continued follow-up for late complications is required in this patient population.

Traumatic aortic transection in a child with an anomalous right subclavian artery.

We describe a child who presented with a traumatic aortic transection in the setting of anomalous origin of the right subclavian artery. This abnormal arch anatomy may influence the diagnosis, anatomic location, and technique of surgical repair of the injury.

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.

Long-term survival after pediatric cardiac transplantation and postoperative ECMO support.

BACKGROUND: Graft failure after cardiac transplantation in children can be managed acutely with mechanical support, most commonly extracorporeal membrane oxygenation (ECMO). The purpose of this study was to evaluation the long-term outcome of ECMO support early and late after pediatric cardiac transplantation. METHODS: From February 1982 through October 2002, 168 patients underwent isolated cardiac transplantation. Twenty patients (11.9%) required mechanical support early or late after transplantation. Inpatient and outpatient records of these were reviewed. RESULTS: Indication for transplantation was complex congenital heart disease in 12, cardiomyopathy in 7, and graft failure (retransplant) in 1. One patient was also on ECMO preoperatively. Fifteen patients required circulatory support immediately or shortly (less than 6 weeks) after transplantation. The remaining 5 patients were placed on ECMO for ventricular dysfunction late (3 months to 7 years) after transplantation. In the perioperative ECMO group, 8 (53%) were successfully decannulated and subsequently discharged. Three of 5 (60%) patients placed on ECMO late were successfully decannulated, 1 of whom died in hospital 10 days later and 2 of whom are still alive. CONCLUSIONS: Mechanical circulatory support using ECMO can be a useful strategy is the management of graft dysfunction after pediatric cardiac transplantation both early and late postoperatively. The mortality rate is acceptable in this very high risk group of patients and long-term outcome is good.