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Background. Hemodilution is a prominent problem in cardiopulmonary bypass in a pediatric population. Ultrafiltration is a method used to reduce fluid volume and tissue edema and to increase hematocrit without the need for blood products.... more
Background. Hemodilution is a prominent problem in cardiopulmonary bypass in a pediatric population. Ultrafiltration is a method used to reduce fluid volume and tissue edema and to increase hematocrit without the need for blood products. Modified ultrafiltration may offer advantages in comparison with conventional ultrafiltration. Methods. This article reviews the technique of modified ultrafiltration and its use, results, complications, and safety in pediatric cardiopulmonary bypass. Results. Modified ultrafiltration in pediatric cardiopulmonary bypass reduces total body water and serum levels of inflammatory mediators. It results in an elevated hematocrit without the need for transfusion, improved pulmonary compliance in the immediate postbypass period, and probably improved cerebral metabolic recovery after deep hypothermic circulatory arrest. Conclusions. Modified ultrafiltration can be performed safely in neonatal patients after cardiopulmonary bypass and offers advantages in c...
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This article reviews the use of intraoperative echocardiography during repair of congenital heart defects. Although initial experience was generated using epicardial transducers, there has been a trend in recent years toward the use of... more
This article reviews the use of intraoperative echocardiography during repair of congenital heart defects. Although initial experience was generated using epicardial transducers, there has been a trend in recent years toward the use of transesophageal echocardiography (TEE) in the operating room. This has encouraged increased involvement from cardiologists and anesthesiologists. New probe designs have provided biplane imaging via the TEE approach in infants weighing more than 2.5 kg. Smaller infants may still require epicardial imaging, so it is helpful for surgeons to maintain some skill in this technique. This article reviews the utility of intraoperative echocardiography for various congenital heart defects by providing examples from our experience at Duke University Medical Center since 1987 with close to 2,000 cases. Furthermore, we review and report for the first time our experience with TEE since 1993 in the operating room during infant heart surgery (493 patients). Along wit...
Surgical management of refractory ectopic supraventricular tachycardia arising in the left atrium requires cryoablation of the bundle of His and insertion of a permanent ventricular pacemaker. This study was designed to develop a... more
Surgical management of refractory ectopic supraventricular tachycardia arising in the left atrium requires cryoablation of the bundle of His and insertion of a permanent ventricular pacemaker. This study was designed to develop a technique to isolate the left atrium electrically from the remainder of the heart, so that an artificial pacemaking system would be unnecessary. Ten adult dogs were subjected to cardiopulmonary bypass and a standard left atriotomy was extended anteriorly across the mitral valve anulus between the right and left fibrous trigones. Posteriorly, the atriotomy was extended across the mitral valve anulus just to the left of the posterior crux and interatrial septum. The muscular interatrial fibers accompanying the coronary sinus were cryoablated at -60 degrees C for 2 minutes. Postoperatively, all animals remained in normal sinus rhythm. Rapid left atrial pacing did not affect the rate or rhythm of the remainder of the heart. Preliminary hemodynamic measurements ...
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The direct endocardial surgical techniques introduced for the treatment of refractory ischemic ventricular tachyarrhythmias have resulted in decreased surgical mortality rates and increased success rates in comparison to previous indirect... more
The direct endocardial surgical techniques introduced for the treatment of refractory ischemic ventricular tachyarrhythmias have resulted in decreased surgical mortality rates and increased success rates in comparison to previous indirect techniques. Since the mechanism of action of one of these new techniques, the encircling endocardial ventriculotomy (EEV), is unknown, the present study was designed to clarify the electrophysiological effects of this procedure. Epicardial and intramural electrophysiology was studied in 18 dogs before and after undergoing an EEV. In the absence of induced myocardial ischemia, the procedure caused an epicardial conduction delay of 23 +/- 3 msec (p less than 0.0001) across the boundaries of the incision. When the EEV enriched acutely ischemic myocardium, it was capable in certain instances of isolating spontaneous ventricular electrical activity to the myocardium encompassed by the incision and thereby protecting the remainder of the heart from the a...
Research Interests: Electrophysiology, Medicine, Electrocardiography, Dogs, Methods, and 15 moreHumans, Transducers, Female, Animals, Male, Clinical Sciences, Middle Aged, Coronary Circulation, Heart Ventricles, Tachycardia, Cardiopulmonary bypass, Diastole, systole, Cardiovascular medicine and haematology, and endocardium
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We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during... more
We examined the relationship of changes in partial pressure of carbon dioxide on cerebral blood flow responsiveness in 20 pediatric patients undergoing hypothermic cardiopulmonary bypass. Cerebral blood flow was measured during steady-state hypothermic cardiopulmonary bypass with the use of xenon 133 clearance methodology at two different arterial carbon dioxide tensions. During these measurements there was no significant change in mean arterial pressure, nasopharyngeal temperature, pump flow rate, or hematocrit value. Cerebral blood flow was found to be significantly greater at higher arterial carbon dioxide tensions (p less than 0.01), so that for every millimeter of mercury rise in arterial carbon dioxide tension there was a 1.2 ml.100 gm-1.min-1 increase in cerebral blood flow. Two factors, deep hypothermia (18 degrees to 22 degrees C) and reduced age (less than 1 year), diminished the effect carbon dioxide had on cerebral blood flow responsiveness but did not eliminate it. We c...
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Routine epicardial two-dimensional echocardiography, Doppler, and Doppler color flow imaging studies were performed before and after cardiopulmonary bypass in 328 patients undergoing operations for congenital heart disease. Ages ranged... more
Routine epicardial two-dimensional echocardiography, Doppler, and Doppler color flow imaging studies were performed before and after cardiopulmonary bypass in 328 patients undergoing operations for congenital heart disease. Ages ranged from 1 day to 59 years (mean 5.9 ...
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The presence of mid-diastolic flow reversal on the mitral valve Doppler inflow indicates abnormal left ventricular filling. To determine whether mid-diastolic flow reversal predicts outcome in patients undergoing repair or palliation of... more
The presence of mid-diastolic flow reversal on the mitral valve Doppler inflow indicates abnormal left ventricular filling. To determine whether mid-diastolic flow reversal predicts outcome in patients undergoing repair or palliation of neonatal congenital heart disease, we reviewed the echocardiograms and medical records of 40 patients with either left ventricular outflow obstruction or transposition of the great arteries. All patients underwent surgical repair; transposition of the great arteries (TGA) = 17, coarctation of the aorta (CoA) = 14, interrupted aortic arch (IAA) = 8, and aortic stenosis (AS) = 1. The presence of mid-diastolic flow reversal was determined by pulsed Doppler interrogation of the mitral valve on preoperative and postoperative echocardiograms. Preoperative echocardiograms showed diastolic flow reversal in only 5 patients; 1 of 1 with AS and 4 of 14 with CoA. Twenty-one of 40 patients showed postoperative diastolic flow reversal; 1 of 1 with AS, 8 of 8 with IAA, 1 of 14 with CoA, and 11 of 17 with TGA. Postoperative mid-diastolic flow reversal 1 to 3 days after surgery was associated with higher mortality rate: 7 of 21 patients with diastolic flow reversal and 0 of 19 without diastolic flow reversal died. Patients with diastolic flow reversal who survived had longer intensive care unit (26.2 +/- 13.5 days vs 7.1 +/- 4.1 days, P <.001) and hospital (57.4 +/- 38.8 days vs 14.8 +/- 5.2 days, P <.05) stays. Mid-diastolic flow reversal is an indicator of prolonged hospital stay and mortality in patients with left ventricular outflow tract obstruction or TGA.
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Ross M. Ungerleider, MD,* Ronald J. Kanter, MD,t Martin O'Laughlin, MD,t A. Resai Bengur, MD,t Page AW Anderson, MD,t J. Rene Herlong, MD,t Jennifer Li, MD,t Brenda E. Armstrong, MD,t Marjorie E. Tripp, MD,t Arthur Garson, MD, MPH,4... more
Ross M. Ungerleider, MD,* Ronald J. Kanter, MD,t Martin O'Laughlin, MD,t A. Resai Bengur, MD,t Page AW Anderson, MD,t J. Rene Herlong, MD,t Jennifer Li, MD,t Brenda E. Armstrong, MD,t Marjorie E. Tripp, MD,t Arthur Garson, MD, MPH,4 Jon N. Meliones, MD,t James ...
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Background: Hemostasis in cardiac surgery patients requires functional platelets. Acquired platelet function defects are well recognized in high shear aortic lesions in adults and have been described in some congenital cardiac patients... more
Background: Hemostasis in cardiac surgery patients requires functional platelets. Acquired platelet function defects are well recognized in high shear aortic lesions in adults and have been described in some congenital cardiac patients with ventricular septal defects (VSDs) and with pulmonary hypertension. Abnormal shear flow is characteristic of many congenital cardiac defects. We hypothesized that platelet function abnormalities might be common in this patient group. The Platelet Function Analyzer -100 (PFA-100) is commonly used to test for platelet function defects. Pediatric reference ranges are the same as adult. Prolongation of closure times to collagen/epinephrine are common in patients on aspirin and related antiplatelet agents, with prolongation to collagen/ADP being characteristic of many clinically significant platelet disorders (congenital and acquired vonWillebrand’s disease, other platelet function defects). Methods: We used the PFA-100 to preoperatively screen pediatr...
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IntroductionFormal training in team leadership is not taught in biomedical research graduate training programs or medical schools.MethodsWe piloted a Leadership Training Workshop for graduate biomedical and medical students enrolled in... more
IntroductionFormal training in team leadership is not taught in biomedical research graduate training programs or medical schools.MethodsWe piloted a Leadership Training Workshop for graduate biomedical and medical students enrolled in our Interprofessional Research Design Course.ResultsThe Kane–Baltes self-efficacy survey demonstrated improved leadership skills (median scores pretraining and post-training were 71 and 76.6; paired t-test, p=0.04).ConclusionsMost students demonstrated significant improvement in self-awareness pertaining to their own innate leadership styles.
Pulmonary valve replacement is becoming the most frequent congenital heart surgery performed on adolescents and young adults. Numerous surgical options are available, including autologous pericardium, mechanical valves, allografts, and... more
Pulmonary valve replacement is becoming the most frequent congenital heart surgery performed on adolescents and young adults. Numerous surgical options are available, including autologous pericardium, mechanical valves, allografts, and bioprosthetic valves. Each option has limitations with durability and freedom from reintervention for stenosis or insufficiency, particularly in the pediatric population. The purpose of this study was to analyze our uniquely designed, expanded polytetrafluoroethylene (ePTFE) valved conduit (VC) for right ventricular outflow tract reconstruction. Beginning in 2012, ePTFE VC were implanted in 26 patients with a median age of 9.8 years (range, 1.0 to 15.9). Bicuspid VC were used in the first 3 patients, and tricuspid VC were used in 23 patients. The ePTFE VC is fashioned from commercially available ePTFE tube graft (16 mm in 1 patient, 20 mm in 7 patients, 24 mm in 18 patients) and 0.1 mm thick ePTFE membrane for the leaflet material. Valve function was ...
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There are scant data in pediatrics on the optimal timing for aortic valve repair (AVR). This study assesses the midterm response to AVR and possible predictors of poor outcome. From 2001 to 2006, 41 patients had greater than 3-month... more
There are scant data in pediatrics on the optimal timing for aortic valve repair (AVR). This study assesses the midterm response to AVR and possible predictors of poor outcome. From 2001 to 2006, 41 patients had greater than 3-month follow-up after AVR for aortic insufficiency, aortic stenosis, or both. Pre-, peri-, and post-operative data were collected, including demographics and clinical symptoms. Two reviewers measured echocardiographic parameters from the pre-operative and latest follow-up echocardiograms. Ventricular dimensions were indexed to body surface area (z-score). Median age at AVR was 13 years with 83 % having a Ross operation. The average left ventricular end-diastolic dimension pre-op, z-score of +1.3, significantly decreased at last follow-up to a mean z-score of -0.1 (p < 0.001). Similarly the indexed LV mass decreased from +3.9 to +0.5 (p < 0.001). There was no significant correlation between the presence of pre-op symptoms and the presence of post-op LV di...
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Complications from systemic inflammation are reported in neonates following exposure to cardiopulmonary bypass. Although the use of asanguinous primes can reduce these complications, in neonates, this can result in significant... more
Complications from systemic inflammation are reported in neonates following exposure to cardiopulmonary bypass. Although the use of asanguinous primes can reduce these complications, in neonates, this can result in significant haemodilution, requiring addition of blood. This study investigates whether the addition of blood after institution of bypass alters the inflammatory response compared with a blood prime. Neonatal swine were randomised into four groups: blood prime, blood after bypass but before cooling, blood after cooling but before low flow, and blood after re-warming. All groups were placed on central bypass, cooled, underwent low flow, and then re-warmed for a total bypass time of 2 hours. Although haematocrit values between groups varied throughout bypass, all groups ended with a similar value. Although they spent time with a lower haematocrit, asanguinous prime groups did not have elevated lactate levels at the end of bypass compared with blood prime. Asanguinous primes...
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Research Interests: Surgery, Forecasting, Humans, Correlation, Exploration, and 15 moreHeart, Infant, Risk factors, Clinical Sciences, Retrospective Studies, Assay, Age Factors, Risk Factors, Congenital Heart Disease, Sensitivity and Specificity, Cohort Studies, Nino, Cardiopulmonary bypass, Patient discharge, and Cardiovascular medicine and haematology
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We report a post-Norwood Stage I patient requiring ECMO support using Argatroban as an anticoagulant following diagnosis of heparin-induced thrombocytopenia (HIT). A 2.6 kg female was born with hypoplastic left heart syndrome and... more
We report a post-Norwood Stage I patient requiring ECMO support using Argatroban as an anticoagulant following diagnosis of heparin-induced thrombocytopenia (HIT). A 2.6 kg female was born with hypoplastic left heart syndrome and underwent a Norwood Stage I operation on day 4 of life. The patient weaned off cardiopulmonary bypass with no complications and was routinely placed on a ventricular assist device (VAD) for 3 days. Heparin was infused at a rate of 16-32 IU/ kg/h to maintain an ACT of 160-180 seconds. Two days after VAD termination, the patient was placed on continuous veno-veno hemofiltration (CVVH). Shortly after CVVH, the patient was diagnosed with HIT and placed on an Argatroban infusion. Five days later, a VAD and subsequent ECMO was used because of decreasing left ventricular function, gross body edema, and poor renal function. This case report summarizes the use of Argatroban during VAD and ECMO support for a patient diagnosed with HIT.
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To correlate the initial and maximal lactate levels with the occurrence of intracranial hemorrhage (ICH) and survival in patients treated with extracorporeal life support (ECLS). Retrospective chart review. Pediatric intensive care unit.... more
To correlate the initial and maximal lactate levels with the occurrence of intracranial hemorrhage (ICH) and survival in patients treated with extracorporeal life support (ECLS). Retrospective chart review. Pediatric intensive care unit. Eighty-two neonatal patients placed on ECLS for respiratory failure due to sepsis, meconium aspiration, or persistent pulmonary hypertension of the newborn. The initial lactate level measured within 6 hours of initiating ECLS and the maximal lactate level measured throughout the ECLS course were collected. Lactate levels were described as mean lactate +/- SE (mM). Head ultrasound reports and survival were reviewed. Platelet counts and activated clotting times (ACTs) were examined. The mean initial and maximal lactate levels were higher in ECLS patients who developed ICH (initial: 10 +/- 1.7 mM vs 6.4 +/- 0.8 mM, p = .05 and maximal: 12.4 +/- 2.5 mM vs 7.9 +/- 0.8 mM, p = .04). Initial and maximal lactate levels were also elevated in nonsurvivors (initial: 11.7 +/- 3 mM vs 6.4 +/- 0.7 mM, p = .01 and maximal: 14.8 +/- 3.3 mM vs 7.8 +/- 0.8 mM, P &lt; .01). Platelet counts and ACT did not differ in patients with and without ICH. Lactate is a useful marker for the development of ICH in ECLS patients. In addition, elevated lactates during ECLS identify a subgroup of patients with poor outcome. Prospective studies are needed to determine whether the incorporation of this information into pre-ECLS and ECLS management will decrease the occurrence of ICH and improve survival.
Research Interests: Pediatrics, Survival Analysis, Humans, Newborn Infant, Retrospective Studies, and 8 moreCerebral Hemorrhage, Logistic Models, Predictive value of tests, Respiratory distress, Extracorporeal Membrane Oxygenation, Psychology and Cognitive Sciences, Respiratory insufficiency, and Medical and Health Sciences
We review the new technology and methods available for support of intraoperative and intraprocedural imaging in the catheterization laboratory for surgical and interventional catheterization procedures in the treatment of congenital heart... more
We review the new technology and methods available for support of intraoperative and intraprocedural imaging in the catheterization laboratory for surgical and interventional catheterization procedures in the treatment of congenital heart disease. The methods reviewed include miniaturized probes and new ways of using them perioperatively for cardiac imaging from transesophageal, substernal, and intracardiac imaging locations. The smaller and more versatile the probes, the better adapted they will be in providing methods to improve the outcomes in babies born with serious forms of congenital heart disease.
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This case report describes chylous ascites associated with a CHD in a 4-month-old infant. Although atraumatic chylous ascites are a rare clinical finding, the recognition and treatment of chylous ascites influence the timing of cardiac... more
This case report describes chylous ascites associated with a CHD in a 4-month-old infant. Although atraumatic chylous ascites are a rare clinical finding, the recognition and treatment of chylous ascites influence the timing of cardiac surgery.
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The pulmonary autograft, or Ross procedure, has theoretical hemodynamic benefits over other aortic valve replacements. The hemodynamic performance of the pulmonary autograft and pulmonary homograft components of this procedure have not... more
The pulmonary autograft, or Ross procedure, has theoretical hemodynamic benefits over other aortic valve replacements. The hemodynamic performance of the pulmonary autograft and pulmonary homograft components of this procedure have not been well defined. Twenty patients with pulmonary autograft replacement of the aortic valve and six with aortic homografts underwent exercise echocardiography with assessment of exercise duration, left ventricular dimensions, mass, and function. Hemodynamics at rest and maximal exercise, including Doppler gradients and effective orifice area (EOA), were measured across the pulmonary autograft and aortic homograft valves. Doppler gradients across the pulmonary homograft valves were compared to native pulmonary valve gradients at rest and maximal exercise. Both groups of patients had excellent self-reported and measured exercise capacity. In comparison to the aortic homograft, the pulmonary autograft had lower peak Doppler gradients across the neoaortic valve at rest (5 +/- 2 versus 11 +/- 4 mmHg; p = 0.027) and maximal exercise (10 +/- 5 versus 15 +/- 5 mmHg; p = 0.003) and larger indexed EOA. However, the Ross procedure patients had higher gradients across the pulmonary homograft both at rest (14 +/- 10 versus 3 +/- 1 mmHg; p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) and maximal exercise (25 +/- 22 versus 5 +/- 4 mmHg; p = 0.004). Two patients in the Ross procedure group had significant pulmonary homograft stenosis in short- or mid-term follow up. In comparison to aortic homograft replacement of the aortic valve, pulmonary autograft replacement has superior hemodynamics at rest and during exercise. However, the pulmonary homograft replacement may develop hemodynamically significant stenosis after the Ross procedure.
Research Interests: Humans, Female, Male, Heart rate, Aged, and 15 morePrevalence, Cardiac Catheterization, Middle Aged, Rest, Adult, Time Factors, Age Factors, Disease Progression, Exercise Tolerance, Aortic Valve, Physical Endurance, Pulmonary Artery, Severity of Illness Index, Heart Valve Prosthesis Implantation, and Cardiovascular medicine and haematology
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Background and aim of the study: Concomitant aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) is an established risk factor for diminished postoperative survival. Results from a VA population were reviewed in... more
Background and aim of the study: Concomitant aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) is an established risk factor for diminished postoperative survival. Results from a VA population were reviewed in order to determine factors influencing early and late survival. Methods: Between 1993 and 2003, a total of 401 patients underwent AVR at the authors' institution. Of these patients, 249 (62%; mean age 70.6 years) had combined AVR and CABG. Surgical indications were primarily aortic valve pathology (group A: n = 168; 68%), primarily coronary artery disease (CAD) (group B: n = 55; 22%), and both severe aortic and coronary disease (group C: n = 26; 10%). In total, 177 patients (71%) received a bioprosthesis, and 72 (29%) received a mechanical valve. Short- and long-term outcomes were explored using univariate and multivariable hazard analyses. Results: Overall operative mortality was 6.4%; mortality for groups A, B and C was 4.8%, 9.1% and 11.5%, respectively. On multivariable analysis, significant factors associated with early-phase mortality were NYHA class IV, diabetes, bioprosthetic valve and combined severe aortic and coronary disease. Survival at one and five years was 86% and 62%, respectively. Five-year survival for groups A, B and C was 71%, 63% and 54%, respectively. Significant associated factors for late-phase mortality were the presence of preoperative peripheral vascular disease (PVD) and cerebrovascular disease (CVD). Factors such as age, prior cardiac surgery, number of grafted coronary arteries, and/or effective orifice area index (EOAI) had no significant effect on outcome. Conclusion: Combined AVR/CABG is a marker for decreased survival. Pre-existing factors such as diabetes, PVD and CVD, as well as poor preoperative NYHA functional status, affected survival. Further investigation is needed to assess the influence of the severity of CAD and EOAI on survival. Thoughtful consideration of all these factors is essential for an accurate prediction of survival, and to determine the appropriate type of aortic prosthesis to be used.