Aberrant right subclavian artery: a novel approach and an overview of operative techniques.

An aberrant right subclavian artery (ARSA) is a rare variation of normal anatomy occurring in 0.5% to 1.8% of the population. No current guidelines are available regarding ARSA management, and surgical intervention should be evaluated carefully. Moreover, symptomatic patients with a dominant left arch and aberrant ARSA require a surgical approach from the right side of the chest for ligation and division of the aberrant artery at its origin on the aorta. The ARSA can then be reimplanted onto the right common carotid artery via a supraclavicular incision. The extensive mobilization in the chest allows for easy reimplantation in the supraclavicular region and eliminates reliance on the collateral circulation. Postoperative monitoring is reliable and easy with radial pulse examinations.

Coronary Sinus Ostial Obstruction in Single-Ventricle Congenital Heart Disease: Two Patients With Different Outcomes.

Coronary sinus ostial obstruction is an exceedingly rare anomaly that is particularly important to diagnose in patients with single-ventricle heart disease before surgical palliation. We present 2 cases, an infant and an adult, diagnosed with coronary sinus ostial obstruction, with different clinical outcomes due to timing of diagnosis. (Level of Difficulty: Intermediate.).

Gastrostomy and Tracheostomy After Complete Repair of Tetralogy of Fallot in Children With 22q11.2 Deletion Syndrome.

OBJECTIVES: Caring for a child with gastrostomy and/or tracheostomy can cause measurable parental stress. It is generally known that children with 22q11.2 deletion syndrome are at greater risk of requiring gastrostomy or tracheostomy after heart surgery, although the magnitude of that risk after complete repair of tetralogy of Fallot has not been described. We sought to determine the degree to which 22q11.2 deletion is associated with postoperative gastrostomy and/or tracheostomy after repair of tetralogy of Fallot. DESIGN: Retrospective cohort study. SETTING: Pediatric Health Information System. PATIENTS: Children undergoing complete repair of tetralogy of Fallot (ventricular septal defect closure and relief of right ventricular outflow tract obstruction) from 2003 to 2016. Patients were excluded if they had pulmonary atresia, other congenital heart defects, and/or genetic diagnoses other than 22q11.2 deletion. MEASUREMENTS AND MAIN RESULTS: Two groups were formed on the basis of 22q11.2 deletion status. Outcomes were postoperative tracheostomy and postoperative gastrostomy. Bivariate analysis and Kaplan-Meier analysis at 150 days postoperatively were performed. There were 4,800 patients, of which 317 (7%) had a code for 22q11.2 deletion. There were no significant differences between groups for age at surgery or sex. Patients with 22q11.2 deletion had significantly higher rates of gastrostomy (18% vs 5%; p < 0.001) and higher rates of tracheostomy (7% vs 1%; p < 0.001); there was no difference for mortality. Kaplan-Meier analyses also showed higher rates of gastrostomy (p = 0.024) and tracheostomy (p = 0.037). CONCLUSIONS: The present study establishes rates of postoperative gastrostomy and tracheostomy in children with 22q11.2 deletion after complete repair of tetralogy of Fallot. These data are useful to clinicians for providing families with preoperative counseling.

Gene-environment regulatory circuits of right ventricular pathology in tetralogy of fallot.

The phenotypic spectrum of congenital heart defects (CHDs) is contributed by both genetic and environmental factors. Their interactions are profoundly heterogeneous but may operate on common pathways as in the case of hypoxia signaling during postnatal heart development in the context of CHDs. Tetralogy of Fallot (TOF) is the most common cyanotic (hypoxemic) CHD. However, how the hypoxic environment contributes to TOF pathogenesis after birth is poorly understood. We performed Genome-wide transcriptome analysis on right ventricle outflow tract (RVOT) specimens from cyanotic and noncyanotic TOF. Co-expression network analysis identified gene modules specifically associated with clinical diagnosis and hypoxemia status in the TOF hearts. In particular, hypoxia-dependent induction of myocyte proliferation is associated with E2F1-mediated cell cycle regulation and repression of the WNT11-RB1 axis. Genes enriched in epithelial mesenchymal transition (EMT), fibrosis, and sarcomere were also repressed in cyanotic TOF patients. Importantly, transcription factor analysis of the hypoxia-regulated modules suggested CREB1 as a putative regulator of hypoxia/WNT11-RB1 circuit. The study provides a high-resolution landscape of transcriptome programming associated with TOF phenotypes and unveiled hypoxia-induced regulatory circuit in cyanotic TOF. Hypoxia-induced cardiomyocyte proliferation involves negative modulation of CREB1 activity upstream of the WNT11-RB1 axis. KEY MESSAGES: Genetic and environmental factors contribute to congenital heart defects (CHDs). How hypoxia contributes to Tetralogy of Fallot (TOF) pathogenesis after birth is unclear. Systems biology-based analysis revealed distinct molecular signature in CHDs. Gene expression modules specifically associated with cyanotic TOF were uncovered. Key regulatory circuits induced by hypoxia in TOF pathogenesis after birth were unveiled.

Impact of Regional Cerebral Perfusion on Outcomes Among Neonates Undergoing Norwood Operation.

OBJECTIVES: To evaluate the impact of regional cerebral perfusion (RCP) during heart operation on outcomes in neonates undergoing Norwood operation. METHODS: We performed a retrospective cohort study using data from the Single Ventricle Reconstruction trial data set. The adjusted effect of RCP use on each outcome was studied using a penalized logistic regression model with bootstrap validation. RESULTS: Of 549 patients included in the study, 252 patients (45.9%) received RCP during their heart operation. In univariate comparisons, the majority of the baseline characteristics and preoperative risk factors were similar in the RCP and No RCP group. The total cardiopulmonary bypass (CPB) time and the total cross-clamp (CC) time were longer in the RCP group (RCP vs No RCP, median CPB time: 161 minutes vs 109 minutes; median CC time: 63 minutes vs 43 minutes). In adjusted models, the use of RCP was not associated with decreased mortality and/or need for heart transplant at hospital discharge (odds ratio [OR]: 0.73; 95% confidence interval [CI]: 0.43-1.25) or prolonged mechanical ventilation (OR: 1.20, 95% CI: 0.62-2.28) or prolonged hospital length of stay (OR: 1.30, 95% CI: 0.73-2.30). We demonstrated that use of RCP was associated with longer CPB times, increased use of ultrafiltration, and higher probability of open chest after Norwood operation. CONCLUSIONS: This study did not demonstrate any impact of RCP on in-hospital mortality and/or heart transplantation, prolonged mechanical ventilation, and prolonged hospital length of stay among neonates undergoing Norwood operation.

Ventricular arrhythmia burden after transcatheter versus surgical pulmonary valve replacement.

OBJECTIVE: Comparative ventricular arrhythmia (VA) outcomes following transcatheter (TC-PVR) or surgical pulmonary valve replacement (S-PVR) have not been evaluated. We sought to compare differences in VAs among patients with congenital heart disease (CHD) following TC-PVR or S-PVR. METHODS: Patients with repaired CHD who underwent TC-PVR or S-PVR at the UCLA Medical Center from 2010 to 2016 were analysed retrospectively. Patients who underwent hybrid TC-PVR or had a diagnosis of congenitally corrected transposition of the great arteries were excluded. Patients were screened for a composite of non-intraoperative VA (the primary outcome variable), defined as symptomatic/recurrent non-sustained ventricular tachycardia (VT) requiring therapy, sustained VT or ventricular fibrillation. VA epochs were classified as 0-1 month (short-term), 1-12 months (mid-term) and ≥1 year (late-term). RESULTS: Three hundred and two patients (TC-PVR, n=172 and S-PVR, n=130) were included. TC-PVR relative to S-PVR was associated with fewer clinically significant VAs in the first 30 days after valve implant (adjusted HR 0.20, p=0.002), but similar mid-term and late-term risks (adjusted HR 0.72, p=0.62 and adjusted HR 0.47, p=0.26, respectively). In propensity-adjusted models, S-PVR, patient age at PVR and native right ventricular outflow tract (RVOT) (vs bioprosthetic/conduit outflow tract) were independent predictors of early VA after pulmonary valve implantation (p<0.05 for all). CONCLUSION: Compared with S-PVR, TC-PVR was associated with reduced short-term but comparable mid-term and late-term VA burdens. Risk factors for VA after PVR included a surgical approach, valve implantation into a native RVOT and older age at PVR.

Heparin-Coated Grafts Reduce Mortality in Pediatric Patients Receiving Systemic-to-Pulmonary Shunts.

We aimed to evaluate the outcomes of systemic-to-pulmonary (SP) shunt procedures utilizing heparin-coated (HC) polytetrafluoroethylene (PTFE) vascular grafts compared to uncoated (non-HC) grafts, in order to observe any benefits in pediatric patients. Our institution switched from using non-HC grafts to HC grafts in March 2011. We conducted a retrospective review of consecutive pediatric patients receiving SP shunts from May 2008 to December 2015. Perioperative variables including baseline characteristics, morbidity, mortality, and blood product utilization were evaluated between the HC and non-HC groups. A total of 142 pediatric patients received SP shunts during the study period: 69 patients received HC shunts and 73 patients received non-HC shunts. The HC group had significantly fewer desaturation or arrest events (P < 0.01), fewer shunt occlusions/thromboses (P < 0.01). There was no statistically significant difference in unplanned reoperations between groups (P = 0.18). The HC group demonstrated significantly lower overall 30-day mortality (P < 0.01), as well as shunt-related mortality (P < 0.01). The HC group had significantly lower postoperative packed red blood cell utilization as compared to the non-HC group (P < 0.01). In this study, pediatric patients receiving HC PTFE grafts in SP shunts demonstrated significantly lower shunt-related mortality. The majority of HC grafts remained patent. These findings suggest that HC grafts used in SP shunt procedures may benefit pediatric patients in terms of efficacy and outcomes.

Incidence and outcome of infective endocarditis following percutaneous versus surgical pulmonary valve replacement.

OBJECTIVES: To provide a comparison of the outcome of infective endocarditis (IE) in patients undergoing transcatheter pulmonary valve replacement (TPVR) versus surgical pulmonary valve replacement (SPVR). BACKGROUND: Although TPVR is thought to be associated with a higher risk of IE than SPVR, there is paucity of data to support this. METHODS: Patients who underwent TPVR or SPVR at UCLA between October 2010 and September 2016 were included and retrospectively analyzed. RESULTS: Three hundred forty-two patients underwent PVR at UCLA including 134 SPVR and 208 TPVR. Patients undergoing TPVR were more likely to have had a history of endocarditis than those undergoing SPVR (5.3% vs. 0.7%, P = 0.03) and a right ventricle to pulmonary artery (RV to PA) conduit (37% vs. 17%, P = 0.0001). Two SPVR and seven TPVR patients developed IE with a 4-year freedom from endocarditis of 94.0% in the SPVR versus 84% in the TPVR group (P = 0.13). In patients who underwent TPVR and developed endocarditis, the mean gradient across the RVOT prior to intervention was higher (28.1 ± 4.5 vs. 17.4 ± 0.6 mmHg, P = 0.02) and were more likely to have a conduit (71% vs. 36%, P = 0.049). CONCLUSIONS: In this study, patients undergoing TPVR were not at a higher risk of IE than patients undergoing SPVR. TPVR patients were more likely to have had a prior history of IE and RV-PA conduit. The patients at highest risk were those with stenotic RV to PA conduits who were treated with TPVR.

Wnt11 regulates cardiac chamber development and disease during perinatal maturation.

Ventricular chamber growth and development during perinatal circulatory transition is critical for functional adaptation of the heart. However, the chamber-specific programs of neonatal heart growth are poorly understood. We used integrated systems genomic and functional biology analyses of the perinatal chamber specific transcriptome and we identified Wnt11 as a prominent regulator of chamber-specific proliferation. Importantly, downregulation of Wnt11 expression was associated with cyanotic congenital heart defect (CHD) phenotypes and correlated with O2 saturation levels in hypoxemic infants with Tetralogy of Fallot (TOF). Perinatal hypoxia treatment in mice suppressed Wnt11 expression and induced myocyte proliferation more robustly in the right ventricle, modulating Rb1 protein activity. Wnt11 inactivation was sufficient to induce myocyte proliferation in perinatal mouse hearts and reduced Rb1 protein and phosphorylation in neonatal cardiomyocytes. Finally, downregulated Wnt11 in hypoxemic TOF infantile hearts was associated with Rb1 suppression and induction of proliferation markers. This study revealed a previously uncharacterized function of Wnt11-mediated signaling as an important player in programming the chamber-specific growth of the neonatal heart. This function influences the chamber-specific development and pathogenesis in response to hypoxia and cyanotic CHDs. Defining the underlying regulatory mechanism may yield chamber-specific therapies for infants born with CHDs.

Efficacy of an Extracellular Matrix in Systemic Loading Conditions in Congenital Heart Surgery.

Extracellular matrices (ECM) are commonly used to repair congenital heart defects; however, there is a lack of literature pertaining to outcomes with ECM use in high-pressure conditions. Between 2011 and 2014, a total of 202 patients underwent congenital heart disease repair using the ECM placed in a systemic pressure condition. The operative sites included: defects in the ventricular septum, mitral valve, aortic valve, ascending aorta, and aortic arch. Patients were followed and evaluated for mortality and reoperations due to loss of ECM integrity. Echocardiograms were evaluated for graft malfunction such as aneurysmal dilation, VSD formation, valve malfunction, or outflow tract obstruction. Patients were followed for an average of 1492 days (Median = 1583). Out of the 202 patients, 7 (3.5%) died due to complications unrelated to ECM, and 10 (5%) underwent reoperations due to complications of ECM integrity. Reoperations were as follows: two of 6 patients receiving aortic leaflet replacement required reoperation for leaflet failure; four of 12 patients receiving mitral valve leaflet repairs required reoperation for leaflet failure; and four of 142 patients with VSD repair required reoperation for residual shunting. The average time to reoperation was 208 days. There were no outflow tract obstructions or aneurysmal dilatations observed. This modern case series suggests that the ECM is efficacious and sustainable under systemic conditions in congenital heart defect repair. However, concerns remain about the use of ECM in aortic valve repair and infant mitral valve repair. Further studies are needed to evaluate long-term ECM integrity.

Repair of Complete Atrioventricular Septal Defects With Decellularized Extracellular Matrix: Initial and Midterm Outcomes.

OBJECTIVE: Since April 2010, our institution has repaired complete atrioventricular septal defects (CAVSDs) with a two-patch technique utilizing CorMatrix extracellular material. This material is potentially an attractive patch because of its theorized eventual integration with the host tissue. We sought to analyze initial outcomes of CAVSD repair with CorMatrix. METHODS: Data were collected on consecutive pediatric (age <18) patients receiving two-patch CAVSD repairs with CorMatrix at a single institution from April 2010 to July 2014. Baseline and perioperative characteristics were evaluated. Echocardiograms were evaluated in both the immediate postoperative period and the most recent postoperative follow-up. Variables analyzed included left AV valve performance, residual shunting, left ventricular outflow tract (LVOT) gradient, morbidity, and mortality. RESULTS: Fifteen patients were identified. The average age at operation was 205 days, with mean follow-up time at 1,364 days. Echocardiograms revealed the following: 12 (80%) patients showed either improved or stable left AV valve performance remaining at "mild" or less insufficiency, while two (13%) declined from "none" to mild and one (7%) from mild to "severe," which required reoperation. There was no residual shunting or LVOT obstruction at follow-up. The single (7%) reoperation was performed after three years due to left AV valve zone of apposition dehiscence. No permanent pacemakers were needed, and no deaths were reported. CONCLUSION: Our initial experience with CorMatrix in the repair of CAVSD in children has resulted in good initial and midterm outcomes. The CorMatrix patch remained stable through midterm follow-up, thus may be efficacious for use in CAVSD repair.

4D MUSIC CMR: value-based imaging of neonates and infants with congenital heart disease.

BACKGROUND: 4D Multiphase Steady State Imaging with Contrast (MUSIC) acquires high-resolution volumetric images of the beating heart during uninterrupted ventilation. We aim to evaluate the diagnostic performance and clinical impact of 4D MUSIC in a cohort of neonates and infants with congenital heart disease (CHD). METHODS: Forty consecutive neonates and infants with CHD (age range 2 days to 2 years, weight 1 to 13 kg) underwent 3.0 T CMR with ferumoxytol enhancement (FE) at a single institution. Independently, two readers graded the diagnostic image quality of intra-cardiac structures and related vascular segments on FE-MUSIC and breath held FE-CMRA images using a four-point scale. Correlation of the CMR findings with surgery and other imaging modalities was performed in all patients. Clinical impact was evaluated in consensus with referring surgeons and cardiologists. One point was given for each of five key outcome measures: 1) change in overall management, 2) change in surgical approach, 3) reduction in the need for diagnostic catheterization, 4) improved assessment of risk-to-benefit for planned intervention and discussion with parents, 5) accurate pre-procedural roadmap. RESULTS: All FE-CMR studies were completed successfully, safely and without adverse events. On a four-point scale, the average FE-MUSIC image quality scores were >3.5 for intra-cardiac structures and >3.0 for coronary arteries. Intra-cardiac morphology and vascular anatomy were well visualized with good interobserver agreement (r = 0.46). Correspondence between the findings on MUSIC, surgery, correlative imaging and autopsy was excellent. The average clinical impact score was 4.2 ± 0.9. In five patients with discordant findings on echo/MUSIC (n = 5) and catheter angiography/MUSIC (n = 1), findings on FE-MUSIC were shown to be accurate at autopsy (n = 1) and surgery (n = 4). The decision to undertake biventricular vs univentricular repair was amended in 2 patients based on FE-MUSIC findings. Plans for surgical approaches which would have involved circulatory arrest were amended in two of 28 surgical cases. In all 28 cases requiring procedural intervention, FE-MUSIC provided accurate dynamic 3D roadmaps and more confident risk-to-benefit assessments for proposed interventions. CONCLUSIONS: FE-MUSIC CMR has high clinical impact by providing accurate, high quality, simple and safe dynamic 3D imaging of cardiac and vascular anatomy in neonates and infants with CHD. The findings influenced patient management in a positive manner.

Decoding the Long Noncoding RNA During Cardiac Maturation: A Roadmap for Functional Discovery.

BACKGROUND: Cardiac maturation during perinatal transition of heart is critical for functional adaptation to hemodynamic load and nutrient environment. Perturbation in this process has major implications in congenital heart defects. Transcriptome programming during perinatal stages is an important information but incomplete in current literature, particularly, the expression profiles of the long noncoding RNAs (lncRNAs) are not fully elucidated. METHODS AND RESULTS: From comprehensive analysis of transcriptomes derived from neonatal mouse heart left and right ventricles, a total of 45 167 unique transcripts were identified, including 21 916 known and 2033 novel lncRNAs. Among these lncRNAs, 196 exhibited significant dynamic regulation along maturation process. By implementing parallel weighted gene co-expression network analysis of mRNA and lncRNA data sets, several lncRNA modules coordinately expressed in a developmental manner similar to protein coding genes, while few lncRNAs revealed chamber-specific patterns. Out of 2262 lncRNAs located within 50 kb of protein coding genes, 5% significantly correlate with the expression of their neighboring genes. The impact of Ppp1r1b-lncRNA on the corresponding partner gene Tcap was validated in cultured myoblasts. This concordant regulation was also conserved in human infantile hearts. Furthermore, the Ppp1r1b-lncRNA/Tcap expression ratio was identified as a molecular signature that differentiated congenital heart defect phenotypes. CONCLUSIONS: The study provides the first high-resolution landscape on neonatal cardiac lncRNAs and reveals their potential interaction with mRNA transcriptome during cardiac maturation. Ppp1r1b-lncRNA was identified as a regulator of Tcap expression, with dynamic interaction in postnatal cardiac development and congenital heart defects.

Histologic examination of decellularized porcine intestinal submucosa extracellular matrix (CorMatrix) in pediatric congenital heart surgery.

BACKGROUND: CorMatrix is a decellularized porcine small intestinal submucosa extracellular matrix that has gained attention as a promising alternative to current materials used in cardiac repair. While animal models demonstrate integration of CorMatrix material with host tissue, the histologic characteristics of CorMatrix used in humans are less well-characterized. In this retrospective study, we report our experience with CorMatrix material used in pediatric congenital heart surgery and describe the histology of CorMatrix material and of surrounding native tissue in explanted specimens. METHODS: Records were reviewed of all pediatric patients implanted with CorMatrix from a single institution (2011-2014). Histologic examinations were performed on CorMatrix and other tissues removed. Explanted samples of CorMatrix and adherent tissues were evaluated for inflammation (acute and chronic), fibrosis, necrosis, degenerative changes, eosinophil response, foreign-body giant cell reaction, neovascularization, and calcification of tissues on a semiquantitative basis (0, none; 1, mild; 2, moderate; 3, marked). Presence of degeneration within CorMatrix and necrosis of surrounding tissue were noted. RESULTS: CorMatrix was utilized in 532 pediatric heart reconstruction procedures since 2011. Twelve explanted CorMatrix specimens from 11 pediatric patients including 4 valves (2 mitral and 2 aortic) and 8 outflow/septal/conduit patches were identified and evaluated. Six cases (5 patients) demonstrated clinical evidence of graft failure prior to surgery (n=6, 1%). Chronic inflammation was seen in adjacent native tissue in 11/12 cases and consisted predominantly of a mixed population of lymphocytes, macrophages, and plasma cells. Acute inflammation was seen in three cases (3/12). Fibrosis of the surrounding native tissue was seen in all CorMatrix specimens. Eosinophils were present in 6/12 cases. Calcification in surrounding tissue was present in 3/12 cases. Giant cell reaction in adjacent native tissue was seen in 8/12 cases. Neovascularization was seen in surrounding native tissue in 5/12 cases. Degeneration of CorMatrix material was seen in 9/12 cases. Necrosis of surrounding tissue was also identified in 5/12 cases. CorMatrix was not resorbed and no cases demonstrated any remodeling of CorMatrix material by integration of native mesenchymal cells or myocytes. CONCLUSION: CorMatrix may be associated with a marked inflammatory response, including a foreign-body giant cell reaction and fibrosis of the surrounding native tissue. Degenerative changes of CorMatrix material are also seen in a majority of explanted specimens. No histologic differences were seen between patients with clinical evidence of graft failure versus patients requiring graft removal due to other factors. Additionally, no cases showed evidence of tissue integration or recellularization of patch material. Our overall clinical experience with CorMatrix demonstrates a favorable outcome for pediatric patients undergoing cardiac reconstructive surgery. However, there is no histologic evidence that CorMatrix acts as a scaffold for reconstitution of the native cardiovascular structures.

Effects of acute kidney injury and chronic hypoxemia on fibroblast growth factor 23 levels in pediatric cardiac surgery patients.

BACKGROUND: Fibroblast growth factor-23 (FGF23) levels are elevated in cardiopulmonary bypass (CPB)-associated acute kidney injury (AKI); however, it is unknown how much of the circulating FGF23 is intact and bioactive. Hypoxia may induce FGF23 production, yet its impact in humans is unknown. Pediatric cardiac surgery patients have both a high incidence of CPB-associated AKI and a high prevalence of chronic hypoxemia. METHODS: We assessed the effects of hypoxemia and CPB-associated AKI on C-terminal FGF23 (cFGF23) and intact FGF23 (iFGF23) levels in 32 pediatric cardiac surgery patients with normal estimated glomerular filtration rate (eGFR). Plasma cFGF23 and iFGF23 were measured preoperatively and serially postoperatively. RESULTS: Despite normal renal and ventricular function, preoperative cFGF23 levels were high and elevated out of proportion to iFGF23 levels. Preoperative oxygen saturation measurements correlated inversely with FGF23 levels. Preoperative cFGF23 and oxygen saturation both predicted postoperative AKI. Postoperatively, cFGF23 and iFGF23 increased by 2 h postreperfusion; iFGF23 then returned to baseline, but cFGF23 remained elevated through 24 h postreperfusion. Group status (AKI vs. non-AKI) modified the effect of time on changes in iFGF23 levels but not cFGF23 levels. CONCLUSIONS: Preoperative cFGF23 may predict CPB-associated kidney dysfunction. Changes over time in cFGF23 and iFGF23 levels post-CPB differ. Chronic hypoxemia may affect FGF23 production in humans.

Unrepaired Tetralogy of Fallot with Absent Pulmonary Valve in a Mildly Symptomatic 16-Year-Old Boy.

Absent pulmonary valve is a rare and severe variant seen in only 3% to 6% of patients with tetralogy of Fallot. Fetuses with this combined condition who survive through birth typically need intervention in infancy or early childhood because of respiratory distress, heart failure, or failure to thrive. We describe the unusual case of a mildly symptomatic 16-year-old boy with these conditions who underwent successful primary repair. Our search of the medical literature yielded fewer than 5 cases of tetralogy of Fallot with absent pulmonary valve (or variants with an absent left pulmonary artery) and survival without repair into later adolescence or adulthood.

Use of bivalirudin for anticoagulation during implantation of total artificial heart.

Heparin-induced thrombocytopenia presents a challenge for anticoagulation techniques during cardiac surgery and ventricular assist device implantation. Bivalirudin is currently recommended for use during cardiopulmonary bypass for patients with heparin-induced thrombocytopenia but requires the use of special techniques to avoid blood stagnation. We report the successful use of bivalirudin during cardiopulmonary bypass for implantation of the Total Artificial Heart with late operative bleeding likely resulting from heavy cell saver use.

Arrhythmia recurrence in adult patients with single ventricle physiology following surgical Fontan conversion.

OBJECTIVES: To evaluate the incidence of atrial tachy-arrhythmia (AT) recurrence following conversion from right atrial-pulmonary artery (RA-PA) Fontan to total cavopulmonary connection (TCPC) in adults. BACKGROUND: AT is a recognized sequel of Fontan palliation, especially in RA-PA Fontans, and is associated with significant morbidity. While catheter ablation achieves fairly reliable short-term success with low morbidity, conversion to TCPC with arrhythmia surgery is a highly effective treatment option for the classical Fontan patients with incessant AT. METHODS: Single center retrospective review. RESULTS: Twenty-seven adults underwent Fontan conversion from RA-PA to TCPC, mostly for AT indications (n = 24). Nine (33%) underwent conversion to a lateral tunnel (LT) and 18 (67%) to an extracardiac (EC) Fontan. Two patients died <30 days post-operatively. Both had liver failure and had been turned down for cardiac/liver transplantation. In-hospital complications occurred in 15/27 patients (55%), including recurrence of AT requiring cardioversion in six patients (22%) and persistent pleural effusions in 4 (15%). Mean follow-up was 4.2 years (range 3 months-14 years). Functional capacity improved from mean New York Heart Association (NYHA) class 1.8 pre-conversion to 1.2 post-conversion (P= 0.008). Twenty-one patients had concomitant arrhythmia surgery (MAZE in 12 patients with IART and Cox-MAZE in nine patients with A-Fib +/- IART). Of these, 3/21 (14%) had AT recurrence >3 months following conversion. CONCLUSIONS: Conversion from RA-PA Fontan to TCPC, with arrhythmia surgery, decreases AT recurrence and improves functional capacity. The risk of peri-operative mortality is highest in patients with cirrhosis. AT recurred in 14% of patients.