Risk Factors for Hemolysis During Extracorporeal Life Support for Congenital Diaphragmatic Hernia.

BACKGROUND: Neonates receiving extracorporeal life support (ECLS) for congenital diaphragmatic hernia (CDH) require prolonged support compared with neonates with other forms of respiratory failure. Hemolysis is a complication that can be seen during ECLS and can lead to renal failure and potentially to worse outcomes. The purpose of this study was to identify risk factors for the development of hemolysis in CDH patients treated with ECLS. METHODS: The Extracorporeal Life Support Organization database was used to identify infants with CDH (2000-2015). The primary outcome was hemolysis (plasma-free hemoglobin >50 mg/dL). Potentially associated variables were identified in the data set. Descriptive statistics and a series of nested multivariable logistic regression models were used to identify associations between hemolysis and demographic, pre-ECLS, and on-ECLS factors. RESULTS: There were 4576 infants with a mortality of 52.5%. The overall mean rate of hemolysis was 10.5% during the study period. In earlier years (2000-2005), the hemolysis rates were 6.3% and 52.7% for roller versus centrifugal pumps, whereas in later years (2010-2015), they were 2.9% and 26.5%, respectively. The fully adjusted model demonstrated that the use of centrifugal pumps was a strong predictor of hemolysis (odds ratio: 6.67, 95% confidence interval: 5.14-8.67). In addition, other risk factors for hemolysis included low 5-min Apgar score, on-ECLS complications (renal, metabolic, and cardiovascular), and duration of ECLS. CONCLUSIONS: In our cohort of CDH patients receiving ECLS over 15 y, the use of centrifugal pumps increased over time, along with the rate of hemolysis. Patient- and treatment-level risk factors were identified contributing to the development of hemolysis.

A Multicenter Study of Nutritional Adequacy in Neonatal and Pediatric Extracorporeal Life Support.

BACKGROUND: Malnutrition in critically ill patients is common in neonates and children, including those that receive extracorporeal life support (ECLS). We hypothesize that nutritional adequacy is highly variable, overall nutritional adequacy is poor, and enteral nutrition is underutilized in this population. MATERIALS AND METHODS: A retrospective study of neonates and children (age<18 y) receiving ECLS at 5 centers from 2012 to 2014 was performed. Demographic, clinical, and outcome data were analyzed. Continuous variables are presented as median [IQR]. Adequate nutrition was defined as meeting 66% of daily caloric goals during ECLS support. RESULTS: Two hundred and eighty three patients received ECLS; the median age was 12 d [3 d, 16.4 y] and 47% were male. ECLS categories were neonatal pulmonary 33.9%, neonatal cardiac 25.1%, pediatric pulmonary 17.7%, and pediatric cardiac 23.3%. The predominant mode was venoarterial (70%). Mortality was 41%. Pre-ECLS enteral and parenteral nutrition was present in 80% and 71.5% of patients, respectively. The median percentage days of adequate caloric and protein nutrition were 50% [0, 78] and 67% [22, 86], respectively. The median percentage days with adequate caloric and protein nutrition by the enteral route alone was 22% [0, 65] and 0 [0, 50], respectively. Gastrointestinal complications occurred in 19.7% of patients including hemorrhage (4.2%), enterocolitis (2.5%), intra-abdominal hypertension or compartment syndrome (0.7%), and perforation (0.4%). CONCLUSIONS: Although nutritional delivery during ECLS is adequate, the use of enteral nutrition is low despite relatively infrequent observed gastrointestinal complications.

Bipolar Versus Unipolar Temporary Epicardial Ventricular Pacing Leads Use in Congenital Heart Disease: A Prospective Randomized Controlled Study.

BACKGROUND: To compare the pacing parameters of unipolar versus bipolar temporary ventricular epicardial pacing leads. DESIGN: Prospective Randomized Unblinded Controlled Study. PATIENTS AND METHODS: Fifty patients undergoing surgery for congenital heart disease who were anticipated to require temporary ventricular pacing leads were recruited preoperatively: 25 patients were randomized to receive unipolar temporary ventricular epicardial pacing leads; the remaining 25 were randomized to receive bipolar temporary ventricular epicardial leads. The baseline characteristics of the groups were similar. The pacing parameters were measured daily for up to first seven postoperative days (PODs) with the day of surgery recorded as POD 0. RESULTS: On the day of insertion, the mean pacing and sensing thresholds were similar for both unipolar and bipolar leads. Thresholds progressively deteriorated with each subsequent POD. By POD 4, the mean ± standard deviation pacing threshold of ventricular bipolar lead was 2.87 ± 0.37 mA compared with 5.6 ± 0.85 mA for the unipolar leads (P = 0.005). The decrease in sensing threshold of the unipolar ventricular pacing leads was significantly more than that of bipolar leads (by POD 5, 5.7 ± 2.64 vs 10.33 ± 2.8, P = 0.01). CONCLUSIONS: Our study shows that the bipolar leads (Medtronic 6495, Medtronic Inc., Minneapolis, MN, USA) have superior sensing and pacing thresholds in the ventricular position in patients undergoing surgery for congenital heart disease when compared to the unipolar leads (Medical Concepts Europe VF608ABB, Medical Concepts Europe Inc., Buffalo, NY, USA).

Retrospective Cohort Study Comparing Redo Operations Using Ferromagnetic Dissection and Conventional Monopolar Dissection.

Purpose To evaluate effectiveness of a novel hemostatic dissection tool in patients with congenital heart disease undergoing redo pericardiac dissections. Description This dissection tool employs ferromagnetic energy to cut and coagulate. The unit passes no electric current through the patient, thus eliminating cautery-induced dysrhythmias and electrical interference. Ferromagnetic dissection is precise and reduces thermal injury spread by as much as 90%. Evaluation We case matched 22 patients undergoing reoperation for congenital heart surgery by weight/operation. Group 1 used the ferromagnetic tool, and Group 2 used conventional monopolar cautery for pericardiac dissection. For groups 1 and 2, the mean weight was 27.7 and 28.4, respectively (P = .87). Time (minutes) from skin incision to cardiopulmonary bypass was 71 versus 72 (P = .44), cardiopulmonary bypass (minutes) was 75.6 versus 73.6 (P = .42), total operative time (minutes) was 193 versus 201 (P = .34). Chest tube output/kilogram in first 6 and first 24 hours was 0.4 versus 1.3 (P = .02) and 0.8 versus 2.4 (P = .01) for groups 1 and 2, respectively. Re-exploration for bleeding was 0% versus 9% (P = .07). There was no mortality. Conclusion The ferromagnetic dissection system appears safe and efficacious. Bleeding was significantly decreased and the need for re-exploration reduced.

Measuring the Resting Energy Expenditure in Children on Extracorporeal Membrane Oxygenation: A Prospective Pilot Study.

Both overfeeding and underfeeding critically ill children are problematic. This prospective pilot study evaluated the resting energy expenditure in infants and children requiring extracorporeal membrane oxygenation (ECMO) support. An indirect calorimeter was used to measure oxygen consumption (VO 2 ) and carbon dioxide production (VCO 2 ) from the mechanical ventilator. Blood gases were used to determine VO 2 and VCO 2 from the ECMO circuit. Values from the mechanical ventilator and ECMO circuit were added, and the resting energy expenditure (REE) (Kcal/kg/day) was calculated. Measurements were obtained > 24 hours after ECMO support was initiated (day 2 of ECMO), 1 day before ECMO discontinuation or transfer, and 1 day after decannulation. Data were compared with the predicted energy expenditure. Seven patients aged 3 months to 13 years were included. The REE varied greatly both above and below predicted values, from 26 to 154 KCal/kg/day on day 2 of ECMO support. In patients with septic shock, the REE was > 300% above the predicted value on day 2 of ECMO. Before ECMO discontinuation, two of six (33%) children continued to have a REE > 110% of predicted. Three patients had measurements after decannulation, all with a REE < 90% of predicted. REE measurements can be obtained by indirect calorimetry in children receiving ECMO support. ECMO may not provide metabolic rest for all children as a wide variation in REE was observed. For optimal care, individual testing should be considered to match calories provided with the metabolic demand.

Change in regional (somatic) near-infrared spectroscopy is not a useful indicator of clinically detectable low cardiac output in children after surgery for congenital heart defects.

OBJECTIVE: Near-infrared spectroscopy correlation with low cardiac output has not been validated. Our objective was to determine role of splanchnic and/or renal oxygenation monitoring using near-infrared spectroscopy for detection of low cardiac output in children after surgery for congenital heart defects. DESIGN: Prospective observational study. SETTING: Pediatric intensive care unit of a tertiary care teaching hospital. PATIENTS: Children admitted to the pediatric intensive care unit after surgery for congenital heart defects. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We hypothesized that splanchnic and/or renal hypoxemia detected by near-infrared spectroscopy is a marker of low cardiac output after pediatric cardiac surgery. Patients admitted after cardiac surgery to the pediatric intensive care unit over a 10-month period underwent serial splanchnic and renal near-infrared spectroscopy measurements until extubation. Baseline near-infrared spectroscopy values were recorded in the first postoperative hour. A near-infrared spectroscopy event was a priori defined as ≥20% drop in splanchnic and/or renal oxygen saturation from baseline during any hour of the study. Low cardiac output was defined as metabolic acidosis (pH <7.25, lactate >2 mmol/L, or base excess ≤-5), oliguria (urine output <1 mL/kg/hr), or escalation of inotropic support. Receiver operating characteristic analysis was performed using near-infrared spectroscopy event as a diagnostic test for low cardiac output. Twenty children were enrolled: median age was 5 months; median Risk Adjustment for Congenital Heart Surgery category was 3 (1-6); median bypass and cross-clamp times were 120 mins (45-300 mins) and 88 mins (17-157 mins), respectively. Thirty-one episodes of low cardiac output and 273 near-infrared spectroscopy events were observed in 17 patients. The sensitivity and specificity of a near-infrared spectroscopy event as an indicator of low cardiac output were 48% (30%-66%) and 67% (64%-70%), respectively. On receiver operating characteristic analysis, neither splanchnic nor renal near-infrared spectroscopy event had a significant area under the curve for prediction of low cardiac output (area under the curve: splanchnic 0.45 [95% confidence interval 0.30-0.60], renal 0.51 [95% confidence interval 0.37-0.65]). CONCLUSIONS: Splanchnic and/or renal hypoxemia as detected by near-infrared spectroscopy may not be an accurate indicator of low cardiac output after surgery for congenital heart defects.

Timely Use of Venous-Arterial ECMO to Treat Congenital Pediatric Junctional Ectopic Tachycardia: A Case Report.

Supraventricular tachycardia is the most common tachyarrhythmia in pediatrics. Although postoperative junctional ectopic tachycardia (JET) is a known complication of congenital heart surgery that is typically transient, congenital JET is rare and requires aggressive treatment to maintain hemodynamic stability. We describe the case of a 3-month-old, previously healthy female who presented with heart failure and cardiogenic shock secondary to congenital JET for whom extracorporeal membrane oxygenation (ECMO) provided time for selection of effective therapy. Adenosine, cardioversion, and transesophageal pacing were unsuccessful, and her echocardiogram demonstrated bilateral atrial dilation and severe left ventricular systolic dysfunction. Approximately 8 hours after presentation, venous-arterial ECMO was commenced allowing for successful treatment with amiodarone. Her electrocardiogram demonstrated atrioventricular dissociation consistent with JET. She was successfully decannulated from ECMO after 6 days. Her discharge echocardiogram showed normal ventricular function, and she had no significant ECMO sequelae. This case demonstrates the value of early ECMO initiation for cardiovascular support in pediatric patients with a life-threatening arrhythmia and in cardiogenic shock. ECMO support can allow for full diagnostic and therapeutic decisions to effectively reverse the consequences of uncontrolled arrhythmias unrelated to surgical complications.

Tetralogy of fallot: yesterday and today.

Tetralogy of Fallot (TOF) is a cyanotic congenital cardiac defect that was first described by Stenson in 1672 and later named for Fallot, who in 1888 described it as a single pathological process responsible for (1) pulmonary outflow tract obstruction, (2) ventricular septal defect (VSD), (3) overriding aortic root, and (4) right ventricular hypertrophy. The surgical history of TOF began with the development of the systemic to pulmonary artery shunt (BT shunt) by Blalock, Taussig, and Thomas in 1944. Ten years later complete repair of TOF was performed by Lillehei using cross-circulation and by Kirklin with a primitive cardiopulmonary bypass circuit. Notable contributions by several other surgeons including Bahnson, Ebert, Malm, Trusler, Barratt-Boyes, and Castaneda would lead us into the modern era of surgery. Today, complete repair of TOF is performed before six months of age with low mortality (<2%). In select cases a modified version of the BT shunt is still performed as the initial procedure. Long-term survival rates are excellent (85%-90%). Adult survivors with TOF are an ever-increasing population and may require reintervention, surgically or catheter based. Promising future innovations include percutaneous pulmonary valve replacement, tissue-engineered autologous valves and conduits, and genetic manipulation. This article presents a review of TOF, including the history of surgical treatment, present-day approaches, and long-term outcomes.

Abiomed biventricular assist device as a bridge to transplantation in a 14-year-old with cardiomyopathy resulting from ventricular noncompaction.

Ventricular noncompaction is a rare but well-documented cause of cardiomyopathy. This report presents a case of ventricular noncompaction diagnosed late in end-stage cardiac failure and malignant ventricular arrhythmia, which required an Abiomed biventricular assist device as a bridge to transplantation.

Endocarditis and Incomplete Endothelialization 12 Years after Amplatzer Septal Occluder Deployment.

A 4-year-old boy had a 15-mm atrial septal defect repaired percutaneously with use of an Amplatzer Septal Occluder. At age 16 years, he presented with a week's history of fever, chills, dyspnea, fatigue, and malaise. Cultures grew methicillin-sensitive Staphylococcus aureus. A transesophageal echocardiogram showed a 1.25 × 1.5-cm pedunculated mass on the left aspect of the atrial septum just superior to the mitral valve, and a smaller vegetation on the right inferior medial aspect of the septum. At surgery, visual examination of both sides of the septum revealed granulation tissue, the pedunculated mass, the small vegetation, and exposed metal wires that suggested incomplete endothelialization of the occluder. We removed the occluder and patched the septal defect. The patient returned to full activity after 4 months and was asymptomatic 3 years postoperatively. Our report reinforces the need for further investigation into prosthetic device endothelialization, endocarditis prophylaxis, and recommended levels of physical activity in patients whose devices might be incompletely endothelialized. In addition to reporting our patient's case, we review the medical literature on this topic.

Perventricular device closure of muscular ventricular septal defects on the beating heart: technique and results.

OBJECTIVE: Both surgical management and percutaneous device closure of muscular ventricular septal defects have drawbacks and limitations. This report describes our initial experience with intraoperative device closure of muscular ventricular septal defects without cardiopulmonary bypass in 6 consecutive patients. METHODS: A median sternotomy or a subxiphoid minimally invasive incision was performed. Under continuous transesophageal echocardiographic guidance, the right ventricle free wall was punctured, and a wire was introduced across the largest defect. The Amplatzer (AGA Medical Corporation, Golden Valley, Minn) muscular ventricular septal defect occluding device (a self-expandable double-disk device) was used. An introducer sheath was fed over the wire, with the sheath tip positioned in the left ventricle cavity. The device was then advanced inside the sheath and deployed by retracting the sheath. Associated cardiac lesions, if any, can then be repaired during cardiopulmonary bypass. A similar technique can also be applied for periatrial closure of complex atrial septal defects. RESULTS: The initial 6 patients are presented. Cardiopulmonary bypass was not needed in any patient for placement of the device and needed in 4 patients for repair of concomitant malformations only (double-outlet right ventricle, aortic arch hypoplasia, pulmonary artery band removal). No complications from using this technique occurred. Discharge echocardiograms showed no significant shunting across the ventricular septum. CONCLUSIONS: Perventricular closure of multiple muscular ventricular septal defects is safe and effective. We believe that this could become the treatment of choice for any infant with muscular ventricular septal defects or any child with muscular ventricular septal defect and associated cardiac defects.

Autologous repair of supravalvar pulmonic stenosis.

Native supravalvar pulmonary stenosis is a rare anomaly, but iatrogenic supravalvar pulmonary stenosis occurs after various repairs for congenital heart disease with relative frequency. Surgical techniques such as patching carry the risk of restenosis. We describe a technique of repair using only autologous tissues that can be applied to both native and iatrogenic supravalvar pulmonary stenosis. There were no complications and no patient developed restenosis at follow-up. Autologous repair of supravalvar pulmonary stenosis is an effective technique.

Acute hemodynamic benefit of multisite ventricular pacing after congenital heart surgery.

BACKGROUND: Cardiac dysfunction after congenital heart surgery is a major cause of morbidity and mortality. Cardiac resynchronization through multisite ventricular pacing (MSVP) improves cardiac index and ventricular function, and lowers systemic vascular resistance (SVR) in adults with heart failure and interventricular conduction delay. METHODS: The acute hemodynamic effects of MSVP after congenital heart surgery were assessed. Twenty-nine patients (aged 1 week to 17 years) with prolonged QRS interval had atrial and ventricular unipolar epicardial temporary pacing leads placed at surgery. Group 1 consisted of patients with a single ventricle (n = 14); group 2 included patients with two-ventricle anatomy (tetralogy of Fallot, ventricular septal defect) undergoing ventricular surgery (n = 10); and group 3 included patients with two-ventricle anatomy undergoing other cardiac surgery (n = 5). At a mean postoperative day 1 (range, 0 to 6), blood pressure, systemic and mixed venous oxygen saturations, electrocardiograms, and echocardiograms were obtained before and after 20 minutes of MSVP. RESULTS: The QRS duration decreased with MSVP in all patients (mean, 23%, p < 0.005). Systolic blood pressure improved in all patients (mean, 9.7%, p < 0.005). Cardiac index improved in 19 of 21 patients tested, with no change in 2 patients (mean, 15.1%, p = 0.0001). In 2 patients, MSVP facilitated weaning from cardiopulmonary bypass. Echocardiographic mitral or tricuspid valve inflow was not significantly different with MSVP. CONCLUSIONS: Multisite ventricular pacing results in improved cardiac index and increased systolic blood pressure, and it can also facilitate weaning from cardiopulmonary bypass. Multisite ventricular pacing may be used as adjunct to standard postoperative treatment of cardiac dysfunction after congenital heart surgery.

New Therapeutic Avenues with Hybrid Pediatric Cardiac Surgery.

Abstract Background: Minimally invasive strategies can be expanded by combining standard surgical and interventional techniques. Methods: A longitudinal prospective study was conducted of all pediatric patients who have undergone hybrid cardiac surgery at the University of Chicago Children's Hospital. Hybrid cardiac surgery was defined as combined catheter-based and surgical interventions in either one surgical setting or planned sequential surgical settings within a 24-hour period. Results: Between June 2000 and June 2003, 24 patients were treated with hybrid approaches. Sixteen patients with muscular ventricular septal defects (VSDs)with a mean age of 4 months (range, 2 weeks to 4 years) underwent either sequential Amplatzer device closure in the catheterization laboratory followed by surgical completion (group 1A [n = 9]: right ventricular (RV)outflow tract enlargement, 6 patients; closure of other VSDs, 5 patients; tricuspid valvuloplasty, 3 patients; bidirectional Glenn shunt, 1 patient; Maze procedure, 1 patient; and retrieval of embolized device, 1 patient) or, more recently, a 1-stage intraoperative off-pump device closure (group 1B;n =7)with the subsequent repair of concomitant heart lesions in 5 patients (double-outlet RV, 2 patients; arch hypoplasia/coarctation of the aorta, 2 patients; and pulmonary artery (PA) debanding, 1 patient). Cardioplegic arrest was either avoided or shortened in the muscular VSD patients. Eight patients with branch PA stenoses (group 2)underwent intraoperative PA stenting or stent balloon dilation along with RV outflow procedure (5 patients)or Fontan completion (3 patients with Maze procedure, mitral valvuloplasty, or Damus-Kaye-Stansel procedure in 1 patient each). All patients survived hospitalization. Complications from the hybrid approach in group 1A patients included tricuspid regurgitation in 2 patients, RV disk malposition in 1 patient, embolization of a VSD device into the aorta in 1 patient, and a residual VSD in 1 patient. No complications from the hybrid approach occurred in group 1B patients, and PA rupture from stent overinflation and ventricular dysfunction occurred in 1 patient each in group 2. During a mean follow-up period of 18 months (range, 2-36 months), 2 group 1A patients died suddenly several months after discharge. All of the other patients are doing well. Conclusions: Hybrid pediatric cardiac surgery performed in tandem by surgeons and cardiologists is a safe and effective means of reducing or eliminating cardiopulmonary bypass. Patients with muscular VSDs who are small, have poor vascular access, or have concomitant cardiac lesions are currently treated in one setting with the perventricular approach.

A prospective observational study of human factors, adverse events, and patient outcomes in surgery for pediatric cardiac disease.

OBJECTIVE: To explore the impact of human factors on intraoperative adverse events and compensation mechanisms in pediatric cardiac surgery. METHODS: Prospective observations of pediatric cardiac surgical procedures were conducted. Patient complexity scores were calculated and outcomes recorded. The process of care was divided into epochs. Events were extracted and coded into compensated or uncompensated major and minor adverse events. Linear regression and analysis of variance were used to analyze the relationships between epochs, complexity, adverse events, and outcome. Patient-specific and procedure-specific variables were tested in a forward stepwise logistic regression as predictors of cases with 1 or more major adverse events. RESULTS: One hundred two patients undergoing pediatric cardiac surgery were observed. An average of 1.2 (range 0-6) major adverse events occurred per case. The most common type of major adverse event was cardiovascular, and most occurred during the surgery/postbypass epoch. Cognitive compensation was the most common compensation mechanism for major adverse events. An average of 15.3 minor adverse events occurred per case. Minor adverse events occurred frequently during the surgery/bypass epoch and related to communication and coordination failures. Higher case complexity, longer surgery duration, and higher number of major adverse events per patient correlated with death compared with other outcome groups (P < .01). Case complexity (P < .01) and surgery duration (P < .05) were both significant predictors of major adverse events. CONCLUSIONS: Pediatric cardiac surgery is an ideal model to study the coordinated efforts of team members in a complex organizational structure. Adverse events occurred routinely during pediatric cardiac surgery and were mostly compensated. Case complexity was a significant predictor of major adverse events. The number of major adverse events per patient correlated with clinical outcomes.

Enteroviral sepsis and ischemic cardiomyopathy in a neonate: case report and review of literature.

Neonatal entero-viral sepsis is a rare but fulminant infection with multisystem involvement, often presenting with hepatitis, meningo-encephalitis, disseminated intravascular coagulation (DIC), and myocarditis. Neonatal myocarditis often proves fatal. We report here a case of neonatal enteroviral myocarditis with multisystem organ failure and ischemic cardiomyopathy that was managed medically.