Clinical Outcomes After Tracheostomy in Children With Single Ventricle Physiology: Collaborative Research From the Pediatric Cardiac Intensive Care Society Multicenter Cohort, 2010-2021.

OBJECTIVES: Multicenter studies reporting outcomes following tracheostomy in children with congenital heart disease are limited, particularly in patients with single ventricle physiology. We aimed to describe clinical characteristics and outcomes in a multicenter cohort of patients with single ventricle physiology who underwent tracheostomy before Fontan operation. DESIGN: Multicenter retrospective cohort study.SETTING: Twenty-one tertiary care pediatric institutions participating in the Collaborative Research from the Pediatric Cardiac Intensive Care Society. PATIENTS: We reviewed 99 children with single ventricle physiology who underwent tracheostomy before the Fontan operation at 21 institutions participating in Collaborative Research from the Pediatric Cardiac Intensive Care Society between January 2010 and December 2020, with follow-up through December 31, 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Death occurred in 51 of 99 patients (52%). Cox proportional hazard analysis was performed to determine factors associated with death after tracheostomy. Results are presented as hazard ratio (HR) with 95% CIs. Nonrespiratory indication(s) for tracheostomy (HR, 2.21; 95% CI, 1.14-4.32) and number of weeks receiving mechanical ventilation before tracheostomy (HR, 1.06; 95% CI, 1.02-1.11) were independently associated with greater hazard of death. In contrast, diagnosis of tricuspid atresia or Ebstein's anomaly was associated with less hazard of death (HR, 0.16; 95% CI, 0.04-0.69). Favorable outcome, defined as survival to Fontan operation or decannulation while awaiting Fontan operation with viable cardiopulmonary physiology, occurred in 29 of 99 patients (29%). Median duration of mechanical ventilation before tracheostomy was shorter in patients who survived to favorable outcome (6.1 vs. 12.1 wk; p < 0.001), and only one of 16 patients with neurologic indications for tracheostomy and 0 of ten patients with cardiac indications for tracheostomy survived to favorable outcome. CONCLUSIONS: For children with single ventricle physiology who undergo tracheostomy, mortality risk is high and should be carefully considered when discussing tracheostomy as an option for these children. Favorable outcomes are possible, although thoughtful attention to patient selection and tracheostomy timing are likely necessary to achieve this goal.

ALCAPA in Children with Complex Congenital Heart Disease: A Multicenter Study.

We sought to report characteristics and outcomes of children with complex anomalous left coronary artery from the pulmonary artery (ALCAPA) and to compare the outcomes to children with isolated ALCAPA. We performed a retrospective data analysis of children with ALCAPA who underwent cardiac surgery between 1/2009 and 3/2018 at 21 centers. Characteristics and outcomes of patients with complex ALCAPA are provided using descriptive statistics. Outcomes were compared between complex ALCAPA and isolated ALCAPA using Fisher's exact test. We reviewed 258 patients who underwent surgical repair of ALCAPA at 21 centers. We identified 10 patients (3.9%) with complex ALCAPA. Median age at initial cardiac surgery was 49 days (range: 4 days, 12.8 years). Cardiac lesions associated with ALCAPA were HLHS (n = 3); scimitar syndrome (n = 2); VSD with aortic coarctation (n = 2); VSD with right pulmonary artery discontinuity (1); DORV with mitral atresia (n = 1); and ToF (n = 1). ALCAPA was diagnosed prior to surgical intervention in 1 patient; during the initial cardiac surgery in 4 patients; in the early postoperative period via cardiac catheterization in 3 patients; and later in childhood after initial surgical repair in 2 patients. Following ALCAPA repair, patients with complex ALCAPA, as compared to patients with isolated ALCAPA, were more likely to be placed on ECMO (50% vs 12%, p = 0.002), receive CPR (30% vs 6%, p = 0.017), or suffer operative mortality (50% vs 3%, p < 0.001). Complex ALCAPA is uncommon. All but one with complex ALCAPA was not diagnosed preoperatively and postoperative morbidity and mortality were significantly greater in these complex patients compared to patients with isolated ALCAPA.

Contemporary Multicenter Outcomes for Truncus Arteriosus With Interrupted Aortic Arch.

BACKGROUND: Truncus arteriosus with interrupted aortic arch (TA-IAA) is a rare congenital heart defect with historically poor outcomes. Contemporary multicenter data are limited. METHODS: A retrospective cohort study of children who underwent repair of TA-IAA between 2009 and 2016 at 12 tertiary care referral centers within the United States was performed. Major adverse cardiac events (MACE) were defined as postoperative extracorporeal membrane oxygenation, cardiopulmonary resuscitation, or operative mortality. TA-IAA patients were compared with TA patients who underwent repair during the study period from the same institutions. RESULTS: We reviewed 35 patients with TA-IAA. MACE occurred in 12 patients (34%). Improvement over time was observed during the study period with 11 events (92%) occurring in the first half of the study period (P = .03). Factors associated with MACE included moderate or severe truncal valve insufficiency (P < .01), concomitant truncal valve repair (P = .04), and longer cardiopulmonary bypass duration (P = .02). In comparison with 216 patients who underwent TA repair, patients with TA-IAA had a higher rate of MACE, but this finding was not statistically significant (34% vs 20%, respectively; P = .07). Additionally no differences between TA-IAA and TA groups were observed for unplanned reoperations (14% vs 22%, respectively; P = .3), hospital length of stay (24 vs 23 days, P = .65), or late deaths (7% vs 7%, P = 1.00). CONCLUSIONS: In this contemporary, multicenter cohort the rate of MACE after repair of TA-IAA was high but improved during the study period. Early childhood outcomes of patients with TA-IAA were similar to those with TA.

Challenges to Randomized Trials in Adult and Congenital Cardiac and Thoracic Surgery.

Randomized trials in surgery face additional challenges compared with those in medicine. Some of the challenges are intrinsic to the nature of the field (eg, issues with blinding, learning curve and surgeons' experience, and difficulties in defining the appropriate timing for comparative trials). Other issues are related to the surgical culture, the attitude of surgeons toward randomized trials, and the lack of support by professional and national bodies. In this review, a group of investigators with experience in trials in congenital and adult cardiac and thoracic surgery discusses the key issues with surgical trials and suggests potential solutions.

Cumulative In-Hospital Costs Associated With Single-Ventricle Palliation.

Background: In the SVR (Single Ventricle Reconstruction) Trial, 1-year survival in recipients of right ventricle to pulmonary artery shunts (RVPAS) was superior to that in those receiving modified Blalock-Taussig-Thomas shunts (MBTTS), but not in subsequent follow-up. Cost analysis is an expedient means of evaluating value and morbidity. Objectives: The purpose of this study was to evaluate differences in cumulative hospital costs between RVPAS and MBTTS. Methods: Clinical data from SVR and costs from Pediatric Health Information Systems database were combined. Cumulative hospital costs and cost-per-day-alive were compared serially at 1, 3, and 5 years between RVPAS and MBTTS. Potential associations between patient-level factors and cost were explored with multivariable models. Results: In total, 303 participants (55% of the SVR cohort) from 9 of 15 sites were studied (48% MBTTS). Observed total costs at 1 year were lower for MBTTS ($701,260 ± 442,081) than those for RVPAS ($804,062 ± 615,068), a difference that was not statistically significant (P = 0.10). Total costs were also not significantly different at 3 and 5 years (P = 0.21 and 0.32). Similarly, cost-per-day-alive did not differ significantly for either group at 1, 3, and 5 years (all P > 0.05). In analyses of transplant-free survivors, total costs and cost-per-day-alive were higher for RVPAS at 1 year (P = 0.05 for both) but not at 3 and 5 years (P > 0.05 for all). In multivariable models, aortic atresia and prematurity were associated with increased cost-per-day-alive across follow-up (P < 0.05). Conclusions: Total costs do not differ significantly between MBTTS and RVPAS. The magnitude of longitudinal costs underscores the importance of efforts to improve outcomes in this vulnerable population.

Anomalous Origin of the Left Coronary Artery From the Pulmonary Artery: A Retrospective Multicenter Study.

OBJECTIVES: We aimed to describe characteristics and operative outcomes from a multicenter cohort of infants who underwent repair of anomalous left coronary artery from the pulmonary artery. We also aimed to identify factors associated with major adverse cardiovascular events following anomalous left coronary artery from the pulmonary artery repair. DESIGN: Retrospective chart review. SETTING: Twenty-one tertiary-care referral centers. PATIENTS: Infants less than 365 days old who underwent anomalous left coronary artery from the pulmonary artery repair. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Major adverse cardiovascular events were defined as the occurrence of postoperative extracorporeal membrane oxygenation, cardiopulmonary resuscitation, left ventricular assist device, heart transplantation, or operative mortality. Factors independently associated with major adverse cardiovascular events were identified using multivariable logistic regression analysis. We reviewed 177 infants (< 365 d old) who underwent anomalous left coronary artery from the pulmonary artery repair between January 2009 and March 2018. Major adverse cardiovascular events occurred in 36 patients (20%). Twenty-nine patients (16%) received extracorporeal membrane oxygenation, 14 (8%) received cardiopulmonary resuscitation, four (2%) underwent left ventricular assist device placement, two (1%) underwent heart transplantation, and six (3.4%) suffered operative mortality. In multivariable analysis, preoperative inotropic support (odds ratio, 3.5; 95% CI, 1.4-8.5), cardiopulmonary bypass duration greater than 150 minutes (odds ratio, 6.9 min; 95% CI, 2.9-16.7 min), and preoperative creatinine greater than 0.3 mg/dL (odds ratio, 2.4 mg/dL; 95% CI, 1.1-5.6 mg/dL) were independently associated with major adverse cardiovascular events. In patients with preoperative left ventricular end-diastolic diameter measurements available (n = 116), left ventricular end-diastolic diameter z score greater than 6 was also independently associated with major adverse cardiovascular events (odds ratio, 7.6; 95% CI, 2.0-28.6). CONCLUSIONS: In this contemporary multicenter analysis, one in five children who underwent surgical repair of anomalous left coronary artery from the pulmonary artery experienced major adverse cardiovascular events. Preoperative characteristics such as inotropic support, creatinine, and left ventricular end-diastolic diameter z score should be considered when planning for potential postoperative complications.

Venogram before long-interval repeat cannulation for pediatric extracorporeal membrane oxygenation.

It is rare for children to receive more than one course of support with extracorporeal membrane oxygenation, and in those who do undergo multiple episodes, the interval is usually days to weeks between events. Little data exists on re-cannulation years after an initial extracorporeal membrane oxygenation run, and late repeat cannulation can pose unique challenges. We report the case of a 10-year-old male patient with right jugular vein occlusion due to a previous course of extracorporeal membrane oxygenation as a neonate, who was successfully supported via central cannulation. This case demonstrates the importance of adequate imaging of target vasculature prior to attempting re-cannulation of a previously used vessel. Establishing a thoughtful strategy for late repeat cannulation is essential to achieve safe access in unusual and challenging situations.

Intermediate Outcomes After Repair of Anomalous Left Coronary Artery From the Pulmonary Artery.

BACKGROUND: Multicenter studies on infants with anomalous left coronary artery from the pulmonary artery (ALCAPA) are lacking. We report the intermediate-term outcomes after ALCAPA repair in a multicenter cohort and identify risk factors for reintervention or death after discharge. METHODS: We retrospectively reviewed infants under 1 year of age who underwent ALCAPA repair from January 2009 to March 2018 at 21 US centers. The primary composite outcome was freedom from reintervention or death after discharge. We used the Kaplan-Meier survival analysis to examine freedom from reintervention or death and the Cox proportional hazard analysis to identify risk factors for this composite outcome. RESULTS: One hundred seventy-seven infants underwent ALCAPA repair; 170 (97%) survived to hospital discharge without transplantation. Twenty-three patients were lost to follow-up. The median duration of follow-up in the remaining 147 patients was 3.8 years (25%, 75%: 1.9 years, 6.0 years). Echocardiographic data were available at ∼3 years after discharge in 98 patients. Left ventricular function was normal in 96 patients (98%), whereas 26 patients (27%) had greater than mild mitral valve regurgitation. Sixteen patients (11%) underwent 20 reinterventions with 1 late death. Patients undergoing the Takeuchi procedure or atypical repairs (hazard ratio, 8.0; 95% confidence interval, 2.1-30.0) or with moderate or greater mitral regurgitation on discharge echocardiogram (hazard ratio, 3.4; 95% confidence interval, 1.2-9.1) were at increased risk for reintervention. CONCLUSIONS: Intermediate-term outcomes after ALCAPA repair in infants are favorable. Persistent left ventricular dysfunction and reinterventions were uncommon, and mortality was rare. Patients who required atypical surgical repair or had moderate or greater mitral regurgitation at discharge warrant closer follow-up.

Characteristics and Surgical Outcomes of Patients With Late Presentation of Anomalous Left Coronary Artery From the Pulmonary Artery: A Multicenter Study.

We sought to describe the clinical course and outcomes of patients who are diagnosed with anomalous left coronary artery from the pulmonary artery (ALCAPA) after infancy. We conducted a retrospective evaluation of patients who underwent ALCAPA surgery between January 2009 to March 2018 at 21 US centers. Clinical presentation, inpatient management, and postoperative outcomes of patients repaired ≥1 year of age were described. To characterize this cohort, we compared these data to patients repaired before 1 year of age. Of 248 ALCAPA patients, 71 (29%) underwent repair ≥1 year of age. Among this subset, the median age at diagnosis was 8.3 years. Chronic arrhythmia occurred in 7%. Patients had good postoperative recovery of left ventricle (LV) dysfunction (90%) and LV dilation (75%), although a low incidence of recovery of mitral regurgitation (40%). Compared to infants, older patients were more likely to present with cardiac arrest (11% vs 1%) and less likely to have moderate or worse LV dysfunction or mitral regurgitation. Older patients had significantly less postoperative extracorporeal membrane oxygenation use, and shorter ICU and hospital stay. In the older cohort, operative mortality occurred in only 1 patient and no patient died after discharge (median follow-up 2.7 years). Survival of patients who presented with ALCAPA beyond infancy was excellent, although chronic mitral regurgitation and chronic arrhythmia were not uncommon. Patients who underwent ALCAPA repair ≥1 year of age were less likely to present with LV dysfunction but more likely to present with cardiac arrest than younger patients.

Relationship of Ventricular Morphology and Atrioventricular Valve Function to Long-Term Outcomes Following Fontan Procedures.

BACKGROUND: The influence of ventricular morphology on Fontan outcomes is controversial. OBJECTIVES: This study hypothesized that dysfunction of the single right ventricle (RV) and right atrioventricular valve regurgitation (AVVR) increases over time and adversely impacts late outcomes following a Fontan operation. A single-center retrospective study was performed. METHODS: From 1985 through 2018, 1,162 patients underwent the Fontan procedure at our center and were included in this study. Transplant and takedown free survival, ventricular, and atrioventricular valve dysfunction after Fontan were analyzed. Death or heart transplantation information was obtained from the National Death Index and the Scientific Registry of Transplant Recipients. RESULTS: The follow-up rate was 99%. Morphologic RV was present in 58% of patients. Transplant and takedown free survival were 91%, 75%, and 71% at 10 years, 20 years, and 25 years, respectively. Morphologic RV was an independent risk factor for transplant, takedown free survival (hazard ratio: 2.4; p = 0.008). The AVVR, which preceded ventricular dysfunction in most cases, was associated with the development of ventricular dysfunction after Fontan (odds ratio: 4.3; 95% confidence interval: 2.7 to 6.7; p < 0.001). Furthermore, AVVR and ventricular dysfunction progressed over time after Fontan, especially in the RV (AVVR: p < 0.0001, ventricular dysfunction: p < 0.0001). CONCLUSIONS: Morphologic RV is negatively associated with the long-term survival following the Fontan, possibly due to a tendency toward progressive AVVR and deterioration of the single ventricle function. Additional volume overload caused by AVVR may be one of the main factors accelerating the dysfunction of the single RV, implying that early valve intervention may be warranted.

Multicenter Analysis of Truncal Valve Management and Outcomes in Children with Truncus Arteriosus.

Truncal valve management in patients with truncus arteriosus is a clinical challenge, and indications for truncal valve intervention have not been defined. We sought to evaluate truncal valve dysfunction and primary valve intervention in patients with truncus arteriosus and determine risk factors for later truncal valve intervention. We conducted a retrospective cohort study of children who underwent truncus arteriosus repair at 15 centers between 2009 and 2016. Multivariable competing risk analysis was performed to determine risk factors for later truncal valve intervention. We reviewed 252 patients. Forty-two patients (17%) underwent truncal valve intervention during their initial surgery. Postoperative extracorporeal support, CPR, and operative mortality for patients who underwent truncal valve interventions were statistically similar to the rest of the cohort. Truncal valve interventions were performed in 5 of 64 patients with mild insufficiency; 5 of 16 patients with mild-to-moderate insufficiency; 17 of 35 patients with moderate insufficiency; 5 of 9 patients with moderate-to-severe insufficiency; and all 10 patients with severe insufficiency. Twenty patients (8%) underwent later truncal valve intervention, five of whom had no truncal valve intervention during initial surgical repair. Multivariable analysis revealed truncal valve intervention during initial repair (HR 11.5; 95% CI 2.5, 53.2) and moderate or greater truncal insufficiency prior to initial repair (HR 4.0; 95% CI 1.1, 14.5) to be independently associated with later truncal valve intervention. In conclusion, in a multicenter cohort of children with truncus arteriosus, 17% had truncal valve intervention during initial surgical repair. For patients in whom variable truncal valve insufficiency is present and primary intervention was not performed, late interventions were uncommon. Conservative surgical approach to truncal valve management may be justifiable.

Utilization of inhaled nitric oxide after surgical repair of truncus arteriosus: A multicenter analysis.

BACKGROUND: Elevated pulmonary vascular resistance (PVR) is common following repair of truncus arteriosus. Inhaled nitric oxide (iNO) is an effective yet costly therapy that is frequently implemented postoperatively to manage elevated PVR. OBJECTIVES: We aimed to describe practice patterns of iNO use in a multicenter cohort of patients who underwent repair of truncus arteriosus, a lesion in which recovery is often complicated by elevated PVR. We also sought to identify patient and center factors that were more commonly associated with the use of iNO in the postoperative period. DESIGN: Retrospective cohort study. SETTING: 15 tertiary care pediatric referral centers. PATIENTS: All infants who underwent definitive repair of truncus arteriosus without aortic arch obstruction between 2009 and 2016. INTERVENTIONS: Descriptive statistics were used to demonstrate practice patterns of iNO use. Bivariate comparisons of characteristics of patients who did and did not receive iNO were performed, followed by multivariable mixed logistic regression analysis using backward elimination to identify independent predictors of iNO use. MAIN RESULTS: We reviewed 216 patients who met inclusion criteria, of which 102 (46%) received iNO in the postoperative period: 69 (68%) had iNO started in the operating room and 33 (32%) had iNO initiated in the ICU. Median duration of iNO use was 4 days (range: 1-21 days). In multivariable mixed logistic regression analysis, use of deep hypothermic circulatory arrest (odds ratio: 3.2; 95% confidence interval: 1.2, 8.4) and center (analyzed as a random effect, p = .02) were independently associated with iNO use. CONCLUSIONS: In this contemporary multicenter study, nearly half of patients who underwent repair of truncus arteriosus received iNO postoperatively. Use of iNO was more dependent on individual center practice rather than patient characteristics. The study suggests a need for collaborative quality initiatives to determine optimal criteria for utilization of this important but expensive therapy.

Characteristics and operative outcomes for children undergoing repair of truncus arteriosus: A contemporary multicenter analysis.

OBJECTIVE: We sought to describe characteristics and operative outcomes of children who underwent repair of truncus arteriosus and identify risk factors for the occurrence of major adverse cardiac events (MACE) in the immediate postoperative period in a contemporary multicenter cohort. METHODS: We conducted a retrospective review of children who underwent repair of truncus arteriosus between 2009 and 2016 at 15 centers within the United States. Patients with associated interrupted or obstructed aortic arch were excluded. MACE was defined as the need for postoperative extracorporeal membrane oxygenation, cardiopulmonary resuscitation, or operative mortality. Risk factors for MACE were identified using multivariable logistic regression analysis and reported as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: We reviewed 216 patients. MACE occurred in 44 patients (20%) and did not vary significantly over time. Twenty-two patients (10%) received postoperative extracorporeal membrane oxygenation, 26 (12%) received cardiopulmonary resuscitation, and 15 (7%) suffered operative mortality. With multivariable logistic regression analysis (which included adjustment for center effect), factors independently associated with MACE were failure to diagnose truncus arteriosus before discharge from the nursery (OR, 3.1; 95% CI, 1.3-7.4), cardiopulmonary bypass duration >150 minutes (OR, 3.5; 95% CI, 1.5-8.5), and right ventricle-to-pulmonary artery conduit diameter >50 mm/m2 (OR, 4.7; 95% CI, 2.0-11.1). CONCLUSIONS: In a contemporary multicenter analysis, 20% of children who underwent repair of truncus arteriosus experienced MACE. Early diagnosis, shorter duration of cardiopulmonary bypass, and use of smaller diameter right ventricle-to-pulmonary artery conduits represent potentially modifiable factors that could decrease morbidity and mortality in this fragile patient population.

Multicenter Analysis of Early Childhood Outcomes After Repair of Truncus Arteriosus.

BACKGROUND: Literature describing morbidity and mortality after truncus arteriosus repair is predominated by single-center reports. We created and analyzed a multicenter dataset to identify risk factors for late mortality and right ventricle-to-pulmonary artery (RV-PA) conduit reintervention for this patient population. METHODS: We retrospectively collected data on children who underwent repair of truncus arteriosus without concomitant arch obstruction at 15 centers between 2009 and 2016. Cox regression survival analysis was conducted to determine risk factors for late mortality, defined as death occurring after hospital discharge and greater than 30 days after operation. Probability of any RV-PA conduit reintervention was analyzed over time using Fine-Gray modeling. RESULTS: We reviewed 216 patients with median follow-up of 2.9 years (range, 0.1 to 8.8). Operative mortality occurred in 15 patients (7%). Of the 201 survivors there were 14 (7%) late deaths. DiGeorge syndrome (hazard ratio [HR], 5.4; 95% confidence interval [CI], 1.6 to 17.8) and need for postoperative tracheostomy (HR, 5.9; 95% CI, 1.8 to 19.4) were identified as independent risk factors for late mortality. At least one RV-PA conduit catheterization or surgical reintervention was performed in 109 patients (median time to reintervention, 23 months; range, 0.3 to 93). Risk factors for reintervention included use of pulmonary or aortic homografts versus Contegra (Medtronic, Inc, Minneapolis, MN) bovine jugular vein conduits (HR, 1.9; 95% CI, 1.2 to 3.1) and smaller conduit size (HR per mm/m2, 1.05; 95% CI, 1.03 to 1.08). CONCLUSIONS: In a multicenter dataset DiGeorge syndrome and need for tracheostomy postoperatively were found to be independent risk factors for late mortality after repair of truncus arteriosus, whereas risk of conduit reintervention was independently influenced by both initial conduit type and size.

'Near death' thromboembolic episode following device closure of atrial septal defect.

Life-threatening pulmonary thromboembolism is a rare complication following device closure of an atrial septal defect (ASD). Our case is a 17-year old female who presented with a sudden cardiorespiratory arrest due to pulmonary thromboembolism, 5 months following a device closure of her ASD. She was successfully resuscitated and then underwent removal of the device with the associated clots and patch closure of the ASD. She made an uneventful recovery. We report this case to highlight that life-threatening thromboembolic complications can occur with ASD device closure.

Long-term animal model of venovenous extracorporeal membrane oxygenation with atrial septal defect as a bridge to lung transplantation.

This study evaluated the effectiveness of an atrial septal defect (ASD) with venovenous extracorporeal membrane oxygenation (vv-ECMO) as a bridge to transplantation. Sheep (56 ± 3 kg; n = 7) underwent a right-sided thoracotomy to create the ASD (diameter = 1 cm) and place instrumentation and a pulmonary artery (PA) occluder. After recovery, animals were placed on ECMO, and the PA was constricted to generate a twofold rise in right ventricular (RV) systolic pressure. Sheep were then maintained for 60 hours on ECMO, and data were collected hourly. Five sheep survived 60 hours. One sheep died because of a circuit clot extending into the RV, and another died presumably because of an arrhythmia. Mean right ventricular pressure (mRVP) was 19 ± 3 mm Hg at baseline, averaged 27 ± 7 mm Hg over the experiment, but was not statistically significant (p = 0.27) due to one sheep without an increase. Cardiac output was 6.8 ± 1.2 L/min at baseline, averaged 6.0 ± 1.0 L/min during the experiment, and was statistically unchanged (p = 0.34). Average arterial oxygen saturation and PCO2 over the experiment were 96.8 ± 1.4% and 31.8 ± 3.4 mm Hg, respectively. In conclusion, an ASD combined with vv-ECMO maintains normal systemic hemodynamics and arterial blood gases during a long-term increase in RV afterload.

Use of venovenous extracorporeal membrane oxygenation and an atrial septostomy for pulmonary and right ventricular failure.

BACKGROUND: Right ventricular failure is a major contributor to morbidity and mortality on the lung transplant waiting list. This study was designed to evaluate the effectiveness of an atrial septostomy with venovenous extracorporeal membrane oxygenation (VV-ECMO) as a novel potential bridge to transplantation. METHODS: Adult sheep (58±3 kg; n=12) underwent a clamshell thoracotomy and instrumentation to measure all relevant pressures and cardiac output (CO). Sheep with tricuspid insufficiency (TI [n=5]) and without tricuspid insufficiency (ØTI [n=7]) were examined. After creation of a 1-cm atrial septal defect and initiating VV-ECMO, the pulmonary artery (PA) was banded to allow progressive reduction of pulmonary blood flow, and data were collected. RESULTS: The CO in both groups remained unchanged from baseline at all pulmonary blood flow conditions. With TI, the CO was 5.1±1.2 L/min at baseline versus 5.1±1.2 L/min with a fully occluded PA (p=0.99). For ØTI, the CO was 4.5±1.4 L/min at baseline versus 4.5±1.2 L/min with no pulmonary blood flow (p=0.99). Furthermore, CO was not affected by the presence of TI (p=0.76). Mean right ventricular pressures were significantly lower in the TI group (TI=20.2±11 mm Hg versus ØTI=29.9±8.9 mm Hg; p<0.00001). Right and left atrial mean arterial pressures were not different between both groups (p>0.5). Lastly, VV-ECMO maintained normal blood gases, with mean O2 saturations of 99% ± 4.1% in both groups. CONCLUSIONS: Right to left atrial shunting of oxygenated blood with VV-ECMO is capable of maintaining normal systemic hemodynamics and normal arterial blood gases during high right ventricular afterload dysfunction.