Bidirectional Glenn Research Articles

Staged Biventricular Repair-Oriented Strategy in Borderline Biventricular Repair Candidates with Ventricular Septal Defect.

Although borderline biventricular repair (BVR) candidates unsuitable for primary BVR are often subjected to single-ventricle repair (SVR), some of them reach BVR by staged strategy. We evaluated our staged BVR-oriented strategy in borderline BVR candidates with ventricular septal defect (VSD) in whom a BVR/SVR decision was deferred beyond the neonatal period. Forty-two patients were treated with the approach between 1991 and 2012. They had been followed toward BVR until it was judged impossible. Outcomes, time course toward definitive repair (DR: BVR, SVR, or 1+1/2 ventricle repair), and hemodynamics were reviewed. A total of 57 palliative surgeries were performed before BVR or bidirectional Glenn (BDG), namely procedures to control pulmonary blood flow in 40, to improve mixing in 5, and to promote left ventricle (LV) growth in 5. LV growth was achieved in four patients. There were three cardiac deaths. Except for four awaiting patients, 19 reached BVR (50%), 11 patients were converted to other than BVR, and 28 patients achieved DR (74%) at the median age of 30.9months. Cardiac cath before BVR or BDG performed at the median age of 22.5months revealed well-preserved pulmonary vasculature with the median pulmonary artery pressure of 14mmHg, except three patients unsuitable for SVR. In conclusion, our staged BVR-oriented strategy required longer time course and more complex palliative surgeries compared with a simple SVR strategy. Leaving open the possibility of a late crossover to an SVR pathway is mandatory when adopting staged BVR-oriented strategy in these complex patients.

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

ObjectivePatients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood...

Exercise capacity in the Bidirectional Glenn physiology: Coupling cardiac index, ventricular function and oxygen extraction ratio

In Bi-directional Glenn (BDG) physiology, the superior systemic circulation and pulmonary circulation are in series. Consequently, only blood from the superior vena cava is oxygenated in the lungs. Oxygenated blood then travels to the ventricle where it is mixed with blood returning from the lower body. Therefore, incremental changes in oxygen extraction ratio (OER) could compromise exercise tolerance. In this study, the effect of exercise on the hemodynamic and ventricular performance of BDG physiology was investigated using clinical patient data as inputs for a lumped parameter model coupled with oxygenation equations. Changes in cardiac index, Qp/Qs, systemic pressure, oxygen extraction ratio and ventricular/vascular coupling ratio were calculated for three different exercise levels. The patient cohort (n=29) was sub-grouped by age and pulmonary vascular resistance (PVR) at rest. It was observed that the changes in exercise tolerance are significant in both comparisons, but most significant when sub-grouped by PVR at rest. Results showed that patients over 2 years old with high PVR are above or close to the upper tolerable limit of OER (0.32) at baseline. Patients with high PVR at rest had very poor exercise tolerance while patients with low PVR at rest could tolerate low exercise conditions. In general, ventricular function of SV patients is too poor to increase CI and fulfill exercise requirements. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different exercise levels according to patient specific data.

Management of Elevated ICP After Bidirectional Glenn

Abstract Introduction This problem-based learning discussion (PBLD) resource addresses the challenges of managing elevated intracranial pressure (ICP) in an infant with bidirectional Glenn (BDG) ph...

The assisted bidirectional Glenn: A novel surgical approach for first-stage single-ventricle heart palliation

Outcomes after a modified Blalock-Taussig shunt (mBTS) in neonates with single-ventricle physiology remain unsatisfactory. However, initial palliation with a superior cavopulmonary connection, such as a bidirectional Glenn (BDG), is discouraged, owing to potential for inadequate pulmonary blood flow (PBF). We tested the feasibility of a novel surgical approach, adopting the engineering concept of an ejector pump, whereby the flow in the BDG is "assisted" by injection of a high-energy flow stream from the systemic circulation. Realistic 3-dimensional models of the neonatal mBTS and BDG circulations were created. The "assisted" bidirectional Glenn (ABG) consisted of a shunt between the right innominate artery and the superior vena cava (SVC), with a 1.5-mm clip near the SVC anastomosis to create a Venturi effect. The 3 models were coupled to a validated hydraulic circulation model, and 2 pulmonary vascular resistance (PVR) values (7 and 2.3 Wood units) were simulated. The ABG provided the highest systemic oxygen saturation and oxygen delivery at both PVR levels. In addition to achieving higher PBF than the BDG, the ABG produced a lower single-ventricular workload than mBTS. SVC pressure was highest in the ABG model (ABG: 15; Glenn: 11; mBTS: 3 mm Hg; PVR = 7 Wood units), but at low PVR, the SVC pressure was significantly lower (ABG: 8; Glenn: 6; mBTS: <3 mm Hg). Adopting the principle of an ejector pump, with additional flow directed into the SVC in a BDG, the ABG appears to increase PBF with a modest increase in SVC and pulmonary arterial pressure. Although multiscale modeling results demonstrate the conceptual feasibility of the ABG circulation, further technical refinement and investigations are necessary, especially in an appropriate animal model.

Effect of high altitude exposure on the hemodynamics of the bidirectional Glenn physiology: Modeling incremented pulmonary vascular resistance and heart rate

The considerable blood mixing in the bidirectional Glenn (BDG) physiology further limits the capacity of the single working ventricle to pump enough oxygenated blood to the circulatory system. This condition is exacerbated under severe conditions such as physical activity or high altitude. In this study, the effect of high altitude exposure on hemodynamics and ventricular function of the BDG physiology is investigated. For this purpose, a mathematical approach based on a lumped parameter model was developed to model the BDG circulation. Catheterization data from 39 BDG patients at stabilized oxygen conditions was used to determine baseline flows and pressures for the model. The effect of high altitude exposure was modeled by increasing the pulmonary vascular resistance (PVR) and heart rate (HR) in increments up to 80% and 40%, respectively. The resulting differences in vascular flows, pressures and ventricular function parameters were analyzed. By simultaneously increasing PVR and HR, significant changes (p <0.05) were observed in cardiac index (11% increase at an 80% PVR and 40% HR increase) and pulmonary flow (26% decrease at an 80% PVR and 40% HR increase). Significant increase in mean systemic pressure (9%) was observed at 80% PVR (40% HR) increase. The results show that the poor ventricular function fails to overcome the increased preload and implied low oxygenation in BDG patients at higher altitudes, especially for those with high baseline PVRs. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different PVR increments.

Incidence of acute kidney injury following cardiac catheterization prior to cardiopulmonary bypass in children

To determine whether contrast administration was a risk factor for development of acute kidney injury (AKI) in cyanotic congenital heart disease (CHD) patients undergoing cardiopulmonary bypass (CPB). AKI following CPB or contrast administration is well described. In previous studies, administration of contrast prior to CPB has been shown to increase the risk of AKI. Chronic cyanosis leads to glomerular damage and dysfunction, thus potentially placing this population at increased risk of developing AKI following contrast administration prior to CPB. One hundred twenty-two patients with cyanotic CHD undergoing preoperative cardiac catheterization (PCC) and subsequent CPB at Children's Medical Center of Dallas from January 1, 2007 until November 30, 2010 were identified, looking specifically at bi-directional Glenn (BDG) anastomoses and Fontan procedures. One hundred thirteen patients undergoing PCC ≤ 48 hr prior to and > 5 days prior to CPB were included. Occurrence of AKI following CPB was the primary outcome variable. Logistic regression analysis revealed pre-catheterization serum creatinine was a risk factor for post-CPB AKI (P < 0.001) in both Fontan and BDG patients. All other variables were not significantly associated with the development of AKI in either BDG or Fontan patients. Length of stay (hospital or ICU) was not different among the groups regardless of the occurrence of AKI. In this study of cyanotic CHD patients, contrast administration within 48 hr prior to CPB was not an additional risk factor for the development of AKI.

Cardiopulmonary exercise performance after total cavopulmonary connection with or without prior superior cavopulmonary connection.

To compare cardiopulmonary exercise capacity of patients undergoing primary total cavopulmonary connection (TCPC) with those undergoing TCPC after a prior bidirectional Glenn (BDG). Out of 42 patients in this study, 24 had undergone primary TCPC while 18 had undergone staged TCPC. The peak oxygen consumption (O(2) peak), O(2) pulse, chronotropic index, and other exercise parameters were studied. There were no significant differences in O(2) peak (940 ± 538 vs. 1010 ± 417 mL/min, p=0.42) and O(2) pulse (5.76 ± 3.52 vs. 6.85 ± 2.95) of patients undergoing staged TCPC versus primary TCPC, respectively; however, chronotropic index (0.43 ± 0.23 vs. 0.30 ± 017, p=0.047) was significantly different. Exercise tolerance was the same in fenestrated versus nonfenestrated TCPC groups and age at TCPC less than or more than 7 years. However, O(2) peak and O(2) pulse of patients with extracardiac TCPC was better than patients with lateral tunnel TCPC (p values 0.05, 0.04 and respectively). Some parameters of exercise tolerance of patients with antegrade pulmonary blood flow (APBF) interrupted at the time of BDG were better than those with APBF open. There were no differences in the exercise parameters of patients undergoing a staged versus a primary TCPC, fenestrated versus nonfenestrated TCPC, and age at surgery less than or more than 7 years. Exercise parameters were better in the extracardiac conduit group versus lateral tunnel TCPC groups. Patients who had a TCPC after prior interruption of APBF had better exercise parameters.

Long-term outcomes of common atrioventricular valve plasty in patients with functional single ventricle

Common atrioventricular valve (CAVV) regurgitation is widely known as a risk factor for mortality and Fontan completion in patients with functional single ventricle. Hence, we reviewed our surgical experience with CAVV plasty in Fontan candidates. Staged Fontan strategy and extracardiac total cavopulmonary connection as Fontan modification were our principal approaches in 1995. Since then, 38 consecutive Fontan candidates (21 males, median weight at operation was 7.0 kg and median age was 17 months old) underwent CAVV plasty. Right atrial isomerism was associated with 24 patients. The initial CAVV plasty was performed before inter-stage bidirectional Glenn (BDG) in 3 patients, at BDG in 23, before Fontan in 4 and during Fontan in 8. Since 1995, the modified Alfieri technique with a tailed, expanded, polytetrafluoroethylene tube as a bridging strip was the procedure for repair and 27 patients underwent the procedure. The mean follow-up period was 7.1 years (range 0-17 years). Actuarial survival and freedom from CAVV replacement rates at 1, 5 and 10 years were 81, 70 and 67% and 89, 85 and 75%, respectively. Seven patients ultimately underwent CAVV replacement with one death. Twenty-three of the 38 patients completed Fontan operation (61%). Association with total anomalous pulmonary venous connection (P= 0.01) and CAVV plasty before BDG (P= 0.05) were risk factors for mortality. CAVV plasty for patients with functional single ventricle is still challenging; however, the aggressive and repeated surgical intervention may contribute to provide better life-prognosis. The ventricular volume unloading effect of BDG without additional pulmonary blood flow or Fontan operation did not contribute to maintain CAVV function. Therefore, there would not be any hesitation for CAVV replacement to control CAVVR in the setting of systemic ventricular failure. Although the statistically significant therapeutic superiority of the modified Alfieri technique was not shown so far, further follow-up may reveal the advantage of this easy and simple technique.

Fate of Ventricular and Valve Performance Following Early Bidirectional Glenn Procedure After Norwood Operation Controlled for Hypoplastic Left Heart Syndome Anatomic Subtype

The Norwood operation (NO) with a right ventricle (RV)-to-pulmonary artery (PA) shunt (NRVPA) is reportedly associated with early hemodynamic advantage. Shunt strategy has been implicated in ventricular function. Outcomes after NRVPA compared with classic procedure as part of a strategy involving early bidirectional Glenn (BDG) procedure were analyzed with reference to RV, tricuspid, and neoaortic valve performance. Between January 2005 and December 2010, 128 neonates with hypoplastic left heart syndrome (HLHS) underwent NO. Controlled for aortic/mitral stenosis (AS-MS) subtype, 28 patients underwent NRVPA (group A), and 26 patients had classic procedure (group B). The patients with a non-HLHS single-ventricle anatomy and those who had undergone a hybrid approach for HLHS were excluded from the study. The mean age at NO was 6.8±3.5days in group A and 6.9±3.6days in group B. Transthoracic echocardiographic evaluation (TTE) after NO (TTE-1) at the midinterval between NO and BDG (TTE-2), before BDG (TTE-3), before Fontan (TTE-4), and at the last follow-up evaluation (TTE-5) was undertaken. Cardiac catheterization was used to assess hemodynamic parameters before the Glenn and Fontan procedures. The operative, interstage, and pre-Fontan survival rates for AS-MS after NO were respectively 88.1% (90.3% in group A vs. 84.7% in group B; p=0.08), 82.5% (82.7% in group A vs. 81.8% in group B; p=0.9), and 80.7% (79.5% in group A vs. 81.8% in group B; p=0.9). The median follow-up period was 39.6months (interquartile range 2.7-4.9months). The RV global function, mid- and longitudinal indexed dimensions, fractionated area change before BDG (TTE-1, TTE-2, TTE-3) and after BDG (TTE-4, TTE-5), and right ventricular end-diastolic pressure did not differ statistically between the groups (p>0.05). No statistically significant difference in tricuspid or neoaortic intervention was found between the groups (p>0.05). Controlled for the AS-MS HLHS subtype, shunt strategy showed no midterm survival or hemodynamic (ventricular or valve) impact. At midterm, the follow-up need for neoaortic or tricuspid valve surgical intervention was not affected by shunt selection. The structural ventricular adaptation after reversal of shunt physiology was irrespective of shunt strategy.

Cardiac troponin I, cardiac troponin-specific autoantibodies and natriuretic peptides in children with hypoplastic left heart syndrome

To evaluate serum levels of cardiac troponin I (cTnI), autoantibodies against cardiac troponin (cTnAAbs) and natriuretic peptides during the treatment protocol in children with hypoplastic left heart syndrome (HLHS). In a prospective study, we had 18 consecutive children with HLHS, for whom serum samples were analysed before the Norwood operation, before the bidirectional Glenn (BDG) operation, at the age of one year and before total cavo-pulmonary connection (TCPC). In addition, we performed a cross-sectional study in 22 children examined before TCPC. Controls comprised 34 healthy children. In the prospective study, troponin I was positive in eight children before the Norwood operation. At the next follow-up, six children were positive. Thereafter, in all samples, cTnI was negative. Serum levels of natriuretic peptides decreased during the treatment protocol but remained higher than in controls throughout the study. In the cross-sectional study, cTnI levels were negative, but levels of natriuretic peptides were higher than in controls. Levels of cTnI and natriuretic peptides showed no correlation with oxygen saturation or haemoglobin concentration. Autoantibodies against cardiac troponin appeared in one patient but not in the control children. Cardiac TnI release is common before Norwood and BDG operations; then during the treatment protocol for HLHS, cTnI release resolves and serum levels of natriuretic peptides decrease. This may reflect a reduction of volume overload of the right ventricle during the surgical programme.

Catheter conversion of classic glenn to bidirectional glenn with closure of left central shunt years after surgical attempts

Bidirectional Glenn shunt is usually performed in patients with single ventricle in preparation for a total cavo-pulmonary connection. We present a patient born with complex congenital heart disease consisting of single ventricle, pulmonary atresia, non confluent pulmonary arteries, and anomalous pulmonary venous return in whom surgical bidirectional Glenn was attempted. After multiple surgical attempts she was converted to a Classic Glenn and a central ascending aorta to left pulmonary artery shunt. Several years later by the aid of radiofrequency wire the occluded pulmonary artery segment was canalized establishing continuity between the two pulmonary artery branches with stenting of the intervening segment. The central shunt to the left pulmonary artery was subsequently embolized. Thus this patient was converted in the catheterization laboratory from the physiology of a classic Glenn to the more preferred bidirectional Glenn physiology.

Clinical Outcomes and Resource Use for Infants With Hypoplastic Left Heart Syndrome During Bidirectional Glenn: Summary From the Joint Council for Congenital Heart Disease National Pediatric Cardiology Quality Improvement Collaborative Registry

The National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) registry captures information on interstage management of infants with hypoplastic left heart syndrome (HLHS). The purpose of this study was to identify interstage risk factors for increased resource use and adverse outcomes during bidirectional Glenn (BDG) hospitalization. All infants in the NPC-QIC registry (31 United States hospitals) undergoing BDG surgery were included (December 2009 to August 2010). Patient demographics, interstage variables, operative procedures, and complications were recorded. Days of hospitalization, ventilation, inotrope use, and complications were surrogates of resource use. Logistic regression analysis determined the associations between predictor variables and resource use. Of 162 infants, 105 (65 %) were males. At BDG, the median age was 155 days (range 78-128), mean weight-for-age z-score was -1.6 ± 1.1, mean length-for-age z-score was -1.5 ± 1.7, and mean preoperative oxygen saturation was 78 % ± 7 %. Caloric recommendations were met in 60 % of patients, and 85 % of patients participated in a home-surveillance program. Median days of intubation, inotrope use, and hospitalization were 1, 2, and 7, respectively. There were 4 post-BDG deaths and 55 complications. In multivariate analysis, lower weight-for-age z-score, female sex, and aortic atresia with mitral stenosis were associated with a higher risk of BDG complications. Meeting caloric recommendations before BDG was associated with fewer hospitalization days. Lower weight-for-age z-score was an independent and potentially modifiable risk factor for BDG complications. HLHS infants who met caloric recommendations before BDG had a lower duration of hospitalization at BDG. These data justify targeting nutrition in interstage strategies to improve outcomes and decrease costs for patients with HLHS.

Fontan completion after Norwood with bidirectional Glenn shunt: their haemodynamics and pulmonary artery configuration

We ranked the haemodynamics and pulmonary artery (PA) configurations of Norwood with bidirectional Glenn shunt (NW-G) patients among the other staged Fontan completion (conventional) patients in this study. Between August 2001 and April 2010, 91 consecutive patients completed staged Fontan operations. Among them, NW-G was performed in 11. There was no operative or late death except in one case which resulted from a reoperation after Fontan completion. Although the age at bidirectional Glenn (BDG) and Fontan completion was younger in NW-G (4.2 vs. 10.9 months, P < 0.01, and 2.3 vs. 3.3 years, P < 0.01), the interval between BDG and Fontan completion was not significantly different in these groups (23.6 vs. 28.0 months, P = 0.71). On Fontan completion, the extracardiac conduit size was significantly different (16.4 vs. 17.7 mm, P < 0.01). However, the pulmonary artery size (PA index) and the PA pressure were not significantly different (165.4 vs. 205.1 mm(2)/m(2), P = 0.23, and 13.4 vs. 11.0 mmHg, P = 0.08). Particularly in hypoplastic left heart syndrome patients, the PA index was not significantly different between these groups (165.4 vs. 174.9 mm(2)/m(2), P = 0.59). The NW-G patients could have a subsequent Fontan completion with good results. There was no significant difference with respect to Fontan completion.

Bidirectional Glenn procedure for an infected modified Blalock–Taussig shunt

A 1-month-old girl underwent right modified Blalock-Taussig shunt (mBTS) for pulmonary atresia with hypoplastic right ventricle. Five months after palliation, she suffered from sepsis and progressive desaturation following otitis media. Computed tomography and angiography revealed a pseudoaneurysm surrounding the mBTS graft. After stabilization of the infection, we performed pseudoaneurysm resection, shunt-graft removal, and the bidirectional Glenn (BDG) procedure under cardiopulmonary bypass. Her condition improved, and she was discharged on the 17th day after surgery. When parameters for the partial right heart bypass should permit, the BDG procedure can be a beneficial recovery procedure for the cases of infected pseudoaneurysm after mBTS in Fontan candidates.

Comparison of risk factors and outcomes for pediatric patients listed for heart transplantation after bidirectional Glenn and after Fontan: An analysis from the Pediatric Heart Transplant Study

Patients listed for transplant after the bidirectional Glenn (BDG) may have better outcomes than patients listed after Fontan. This study examined and compared outcomes after listing for BDG and Fontan patients. All patients listed for transplant after the BDG in the Pediatric Heart Transplant Study between January 1993 and December 2008 were evaluated. Comparisons were made with Fontan patients and with a matched cohort of congenital heart disease patients. Competing outcomes analysis and actuarial survival were evaluated for the study populations, including an examination of various risk factors. Competing outcomes analysis for BDG and Fontan patients after listing were similar. There was no difference in actuarial survival after listing or transplant among the 3 cohorts. Mechanical ventilation, United Network of Organ Sharing status, and age were risk factors for death after listing in BDG and Fontan patients, but ventilation at the time of transplant was significant only for the Fontan patients. Mortality was increased in Fontan patients listed < 6 months after surgery compared with patients listed > 6 months after surgery, but no difference was observed in BDG patients. There was a trend toward improved survival after listing for both populations across 3 eras of the study, but this did not reach statistical significance. Outcomes after listing for BDG and Fontan patients are similar. Mechanical ventilation at the time of transplant remains a significant risk factor for death in the Fontan population, as does listing for transplant soon after the Fontan, suggesting that some patients may benefit from transplant instead of Fontan completion.

Clinical outcomes of prophylactic Damus-Kaye-Stansel anastomosis concomitant with bidirectional Glenn procedure

We evaluated prophylactic Damus-Kaye-Stansel (DKS) anastomosis in association with the timing of a bidirectional Glenn (BDG) procedure as second-stage palliation aiming at Fontan completion to prevent late systemic ventricular outflow tract obstruction. Between 1996 and 2005, 25 patients (14 boys; median age, 12 months) underwent a BDG procedure concomitant with DKS anastomosis. All had a systemic ventricular outflow tract through an intraventricular communication or morphologically developed subaortic conus and had previously undergone pulmonary artery banding. Enlargement of intraventricular communication and/or resection of a subaortic conus were not performed before or during the operation. Twenty-one (84%) patients subsequently underwent a Fontan operation, with a follow-up period of 6.8 ± 1.9 years (range, 4-11 years), with no mortalities after the Fontan operation. Cardiac catheterization showed that systemic ventricular end-diastolic volume was significantly decreased from 187% ± 74% of normal before BDG to 139% ± 35% after (P = .038) and to 73% ± 14% at 4.3 years after the Fontan operation (P < .001). However, the pressure gradient across the systemic ventricular outflow tract remained at 0.5 ± 0.8 mm Hg after DKS anastomosis and 0.6 ± 2.3 mm Hg at 4.6 years after the Fontan operation. None of the patients showed more than moderate aortic or neoaortic regurgitation, except 1 who progressed to pulmonary regurgitation after DKS anastomosis and required a reoperation for a systemic ventricular outflow tract. No anatomic properties affected late neoaortic valve function. Regardless of a significant reduction in systemic ventricular volume, DKS anastomosis concomitant with a BDG procedure shows promise for a nonobstructive systemic ventricular outflow tract after a Fontan operation.

Outcomes after Bidirectional Glenn Operation in Single Ventricular Anatomy: A Single Centre Experience

Outcomes after Bidirectional Glenn Operation in Single Ventricular Anatomy: A Single Centre Experience Maqsood M. Elahi 1,∗, Hong C. Chew1, Hari Ravindranathan2, Alan Farnsworth1, Graham R. Nunn1, David Winlaw1, Peter W. Grant 1 1Department of Cardiothoracic Surgery, Sydney Children’s Hospital, Barker Street, Randwick, NSW, Australia 2 Department of Neonatal & Children’s Intensive Care, Sydney Children’s Hospital, Barker Street, Randwick, NSW, Australia Objective: The bidirectional Glenn (BDG) procedure is a well-established procedure. Numerous studies have highlighted its potential benefits in the single-ventricle palliation pathway. We report our experience for predictive variables and outcomes associated with BDG procedures. Methods: Demographics, age at the time of the BDG procedure, associated procedures, length of hospital stay, duration ofmechanical ventilation, length of ICU stay, and primary diagnoses for 29 consecutive patients undergoing the BDG procedure was collected. All data were analysed with Kaplan–Meier survival analysis and the Cox proportional hazard regression test to assess the probability of survival after the BDG procedure. A stepwise regression analysis was performed for identification of independent factors for postoperative oxygen saturation at hospital discharge. and demonstrate that performing BDG procedure at sixmonths of age is feasible and safe. doi:10.1016/j.hlc.2010.11.057 Surgery vs Percutaneous Valvuloplasty for Neonatal and Infant Critical Aortic Stenosis Fountas Nikolas ∗, Cole Andrew, Roberts Philip, Chard Richard ∗ Optimal management for critical aortic stenosis in neonatal and infantpopulations ispoorlyunderstood.This study sought to evaluate outcomes of percutaneous transcatheter balloon valvuloplasty versus surgical therapy. Thirty-nine neonates and 37 infants (mean age 10 days and 4.3 months respectively) underwent treatment for critical aortic stenosis at the Children’s Hospital Westmead between 1998 and 2010. Valvuloplasty was done in 37 (95%) neonates and 37 (100%) infants. Aortic valvotomy, Konno, or Ross-Konno procedures were performed in 12 (31%) neonates and seven (19%) infants. Ten patients had surgery for concomitant aortic coarctation repair (nine), mitral valvotomy/repair (two), or ASD closure (one). Four neonate mortalities occurred (10%); all balloon valvuloplasty related.Re-interventions, either catheteror surgery, occurred in 15 (38%) neonates andnine (24%) infants. Four patients (three neonate, one infant) required both catheter Results: All patients in our study except two required initial palliation with either BT shunt or PA banding in early postnatal care. The mean period from initial surgery to BDG surgerywas approximately 11months. At the time of the BDG procedure, the youngest patient was fivemonths old, and the oldest patient was 4.5 years old. There was an equal distribution of patients with right-sided or leftsided single ventricle anatomy. The postoperative oxygen saturations at discharge (all on room air) were positively associated with previous antegrade flow defined as any flow through the native pulmonary artery and pulmonary valve (P< 0.005) and negatively associated with preoperative end-diastolic ventricular pressure (P< 0.005). Age at the time of the BDG procedure was not associated with worse postoperative oxygen saturations at discharge. There was only one late death (3.4%). Time to Fontan procedure was 23± 4.5 months. The significant independent variables for morbidity in Fontan completion after the BDG procedure were preoperative mean pulmonary artery pressure, bypass time and postoperative oxygen saturations. Conclusion: Our results demonstrated that low mortality in single ventricle anatomy. We found that the post-BDG oxygen saturations at hospital discharge were associated with previous native antegrade flow. We hypothesise that antegrade native pulmonary flow include promotion of normal pulmonary artery growth andmaintenance of pulmonary artery endothelial function for a better outcome towards Fontan completion. Our results support the international trend towards BDG procedure in younger age and surgical re-interventions. Children requiring intervention for congenital critical aortic stenosis as neonates fared worse than infants in mortality and re-intervention rates, and surgery was safe and effective when catheter intervention was unsuccessful. doi:10.1016/j.hlc.2010.11.058 Effect of Physical Activity on Continuous-Flow Left Ventricular Assist Device Function in Outpatients Sharon Hu1,2,3,∗, Anne Keogh1,2, Peter Macdonald1,2, Eugene Kotlyar 1, Desiree Robson1, Michelle Harkess 1, Paul Jansz1,3, Phillip Spratt 1,3, Chris Hayward1,2 1Heart Failure and Transplant Unit, St Vincent’s Hospital, Sydney, Australia 2 Faculty of Medicine, The University of New South Wales, Sydney, Australia 3 Department of Cardiothoracic Surgery, St Vincent’s Hospital, Sydney, Australia Introduction: Left ventricular assist devices (LVADs) augment the heart’s pumping action in patientswithmedically refractory heart failure. Pump flow in continuousflow LVADs have been shown to increase with graded exercise testing [1,2]. However, data on pump behaviour during activities of daily living where cardiac output requirements vary are lacking. Purpose: To observe whether LVAD flow changes with everyday physical activity without active alterations in pump settings.

During treatment protocol for univentricular heart serum levels of natriuretic peptides decrease☆☆☆

In children treated for univentricular heart (UVH), prospective evaluation of serum levels of N-terminal proatriopeptide (ANPN) and N-terminal pro-brain natriuretic peptide (NT-proBNP) was performed. Serum samples were analysed in 19 children before the first operation, before the bi-directional Glenn (BDG) operation, at age 1 year and before total cavopulmonary connection (TCPC). In addition, we performed cross-sectional measurement of peptide levels in 32 children: 22 hypoplastic left ventricle (LV), 10 hypoplastic right ventricle (RV) before; and in 12 children: nine hypoplastic LV, three hypoplastic RV, 2 (range: 0.5-5.3) years after the TCPC operation. Controls comprised 12 children aged less than 6 months and 41 children aged from 6 months to 7 years. Between the first and second operations, peptide levels decreased. Before TCPC, further decreases had occurred. Throughout follow-up, peptide levels were higher than in controls. In the cross-sectional study, before TCPC, median ANPN concentration measured 0.37 (range: 0.18-1.00) nmol l(-1) (P=0.059, compared with controls) and NT-proBNP 155 (range: 13-718) ng l(-1) (P<0.001). After TCPC, median ANPN concentration measured 0.39 (range: 0.09-0.98) nmol l(-1) (P=ns) and NT-proBNP 201 (range: 76-1406) ng l(-1) (P<0.001). Before TCPC, levels of NT-proBNP were higher in patients with RV than with LV morphology. Natriuretic peptide levels decreased during treatment protocol for UVH, but NT-proBNP levels remained higher than in controls. These reflect reduction of volume overload of the single ventricle and can prove useful for haemodynamic monitoring.

Predictors of Poor Weight Gain in Infants with a Single Ventricle

To assess growth from the time of neonatal discharge to the time of performance of the bidirectional Glenn (BDG) procedure in infants with a single ventricle and determine predictors of poor growth. We performed a retrospective case series of infants who underwent the BDG procedure at our institution between January 2001 and December 2007 (n=102). Anthropometric and clinical data were recorded during neonatal hospitalization and before BDG. Outcome variables included weight-for-age z-score (WAZ) at the time of BDG and average daily weight gain between neonatal discharge and BDG. Median age at the time of BDG was 5.1 months (range, 2.4-10 months), and median WAZ was -0.4 (range, -2.6 to 3.2) at neonatal admission and -1.3 (range, -3.9 to 0.6) at the time of BDG. Non-Caucasian infants (P=.03) and those with lower WAZ at neonatal discharge (P<.0001) had a lower WAZ at BDG. Being formula-fed at neonatal discharge (P=.04), and having higher mean pulmonary arterial pressure (P=.04) and systemic oxygen saturation (P=.006) were associated with lower average daily weight gain between neonatal discharge and BDG. Infants with a single ventricle have poor weight gain between neonatal discharge and BDG. Non-Caucasian infants and those with evidence of increased pulmonary blood flow are at particular risk for growth failure.