Long-term incidence of arrhythmias in extracardiac conduit Fontan and comparison between systemic left and right ventricle.

AIMS: The extracardiac conduit-Fontan (ECC) has become the preferred technique for univentricular heart palliation, but there are currently no data on the incidence of long-term arrhythmias. This study investigated the incidence of arrhythmias and relation to single ventricle morphology in the long-term follow-up (FU) in ECC. METHODS AND RESULTS: All patients with ECC performed in our Centre between 1987 and 2017 were included (minimum FU 5 years). Of 353 consecutive patients, 303 [57.8% males, aging 8-50 (median 20) years at last FU] were considered and divided into two groups depending on left (194 in Group 1) or right (109 in Group 2) ventricular morphology. Eighty-five (28%) experienced ≥1 arrhythmic complications, with early and late arrhythmias in 17 (5.6%) and 73 (24.1%) patients, respectively. Notably, late bradyarrhythmias occurred after 6 years in 21 (11%) patients in Group 1, and in 15 (13.8%) in Group 2 [P = 0.48]. Late tachyarrhythmias occurred in 55 (18.2%) patients after 12 years: 33 (17%) in Group 1 and 22 (20.2%) patients in Group 2 [P  = 0.5]. Ventricular tachycardias (VT) were documented after 12.5 years in 14 (7.2%) patients of Group 1 and 15 (13.8%) of Group 2 [P = 0.06] with a higher incidence in Group 2 during the FU [P = 0.005]. CONCLUSION: Extracardiac conduit is related to a significant arrhythmic risk in the long-term FU, higher than previously reported. Bradyarrhythmias occur earlier but are less frequent than tachyarrhythmias. Interestingly, patients with systemic right ventricle have a significantly higher incidence of VT, especially in a very long FU.

Stent expansion of restrictive Fontan conduits to nominal diameter and beyond.

BACKGROUND: Mechanical factors may cause bottlenecks in a Fontan circuit. Extracardiac conduits (ECC) are placed at a young age, but the materials do not allow growth. Restriction in ECC dimensions may deteriorate the function of the circuit. AIMS: This study aimed to evaluate the feasibility and safety of stent expansion of an ECC to the nominal dimension at the time of implant and, if possible, beyond nominal. METHODS: Retrospective, single-center observational review of all ECC Fontan patients who received a stent to expand a previously placed surgical conduit. RESULTS: A total of 44 restrictive conduits were stented over a 14-year study period with a median of 11.8 (interquartile ranges [IQR]: 9.1-13.8) years after ECC placement. Cross-sectional areas were a median of 30% (IQR: 21-42) smaller than the originally placed ECC; there was no gradient in 23/44 patients and in 21/44, a minimal gradient of 1.3 ± 0.5 (range 1-3 mmHg). All conduits could be enlarged with a significant (p < 0.0001) increase in diameter from 13.6 ± 1.8 to 19.2 ± 1.2 mm, corresponding to a median cross-sectional area increase of 171% (IQR: 153-220). In three patients where the conduits were not contracted, expansion of between 127% and 165% was obtained. There were no conduit ruptures and only one minor complication. CONCLUSIONS: ECC in some Fontan patients become smaller than nominal over time, usually without overt symptoms. The dimensions of ECC's can be safely and significantly increased to nominal or even beyond employing stenting. It allows adjustment of ECC dimensions to compensate for somatic growth.

Comparable long-term results of the extracardiac conduit total cavopulmonary connection in heterotaxy to non-heterotaxy patients.

BACKGROUND: Fontan operation in heterotaxy patients has been associated with high mortality. We studied whether adoption of the extracardiac conduit (EC) total cavopulmonary connection (TCPC) in heterotaxy demonstrated comparable results to non-heterotaxy population. METHODS: A retrospective medical record review of 35 consecutive patients with heterotaxy and 70 consecutive patients without heterotaxy syndrome who underwent EC TCPC between 2000 and 2018 was performed. RESULTS: In the 35 heterotaxy patients, 30 were right and 5 were left atrial isomerism. Anomalies of venous return included bilateral superior vena cava in 20 (57.1%), separated hepatic vein in 8 (22.9%), interrupted inferior vena cava in 3 (8.6%), total anomalous pulmonary venous return in 7 (20%), and partial in 2 patients (5.7%). All patients underwent EC TCPC under beating-heart cardiopulmonary bypass except in four patients (11.4%) cardioplegic arrest was needed for cardiac repair. The surgical mortality rate was lower in heterotaxy patients (0% vs. 5.7%; p = 0.299) but statistically not significant. The follow-up ranged from 2 months to 17.8 years (mean 9.4 ± 5.6 years). At 15 years, there was no significant difference between the heterotaxy and non-heterotaxy patients regarding the long-term survival (70% vs. 78.6%; p = 0.443), freedom from reoperation (81.9% vs. 96.5%; p = 0.057), and postoperative arrhythmia (17.1% vs. 7.1%; p = 0.174). CONCLUSIONS: EC TCPC can be performed in heterotaxy patients with comparable early and late results to the non-heterotaxy population. However, the late morbidities regarding the Fontan circulation needs careful follow-up.

Serial Cardiopulmonary Exercise Testing in Patients after Extracardiac Conduit Total Cavopulmonary Connection for Single-Ventricle Hearts: An Observational Study.

OBJECTIVE: To analyze the aerobic fitness and evolution of exercise tolerance in patients with single-ventricle physiology after total cavopulmonary connection (TCPC) with an extracardiac conduit (ECC). STUDY DESIGN: This retrospective cohort study included patients with previous ECC-TCPC who underwent cardiopulmonary exercise testing (CPET) between September 2010 and September 2019. Patients who completed at least 2 tests (≥6 months apart) with adequate levels of effort were recruited for the serial CPET evaluation. RESULTS: We identified 70 patients (50% male) with a mean age of 6.45 ± 5.14 years at ECC-TCPC and 15.67 ± 5.03 years at the initial CPET. The peak oxygen consumption (peak VO2) to predicted value (peak PD) was 55.90 ± 16.81%. Twenty of the 70 identified patients (50% male) were recruited for serial analysis. The average number of CPETs was 2.6 per patient. The average duration from the first CPET to the last CPET was 3.64 years. The peak VO2 and PD increased slowly, with mean rates of 38.77 ± 129.01 mL/min and 1.66 ± 6.40%, respectively, during the study period. CONCLUSIONS: Although the patients had lower exercise tolerance after ECC-TCPC compared with their normal peers, exercise tolerance appears to have been preserved over the adolescent period in those who underwent serial testing after ECC-TCPC.

Transbaffle/transconduit puncture using a simple CARTO-guided approach without echocardiography in patients with congenital heart disease.

INTRODUCTION: Catheter ablation (CA) of atrial tachyarrhythmias (ATs) in patients with complex congenital heart disease (CHD) often requires technically challenging transbaffle or transconduit puncture. The aim was to assess the feasibility and safety of transbaffle/transconduit puncture based on computed tomography (CT) three-dimensional (3D) reconstruction merged with electro-anatomical mapping (EAM) without per-procedure echocardiographic guidance. METHODS AND RESULTS: We included 18 consecutive CHD patients in two centers who had atrial-switch or Fontan surgery and underwent CA of AT by an antegrade approach requiring intracardiac puncture. Twelve patients with atrial-switch surgery and six patients with extracardiac Fontan surgery were referred for CA of AT. Cardiac CT with 3D reconstruction was performed before the procedure. The 3D volume of the systemic venous atrium or extracardiac conduit acquired by EAM was merged with the corresponding CT 3D reconstruction. The ablation catheter was positioned at the optimal puncture site. Under fluoroscopic guidance, the needle was positioned next to the ablation and the puncture was performed. Balloon expansion of the puncture site was performed in every case of transconduit puncture and in two (17%) cases of transbaffle puncture. Overall, 17 intra-atrial reentrant tachycarrythmias and 9 focal ATs were successfully ablated, with no acute complications. The median time to access the pulmonary atrium was 78.5 minutes (range, 55-185) and total median fluoroscopy time was 23 minutes (range, 7-53). CONCLUSIONS: Transbaffle and transconduit punctures can be performed safely in CHD patients by using a simple technique relying on CT 3D reconstruction and EAM.

Dacron Conduit for Extracardiac Total Cavopulmonary Anastomosis: A Word of Caution.

BACKGROUND: The extracardiac conduit technique is a valid option for completing total cavopulmonary anastomosis (TCPC) in patients with a single ventricle. The technique allows for beating heart surgery, optimal flow dynamics, and reduced postoperative atrial arrhythmia. Different types of conduit have been proposed. This study reported a single-centre experience with two different types of conduit. METHODS: Consecutive patients referred for TCPC at the current institution between January 2001 and September 2013 were included. Retrospective extraction of pertinent variables was accomplished through electronic patient chart review. Patients were stratified based on the type of conduit used to perform the TCPC: polytetrafluoroethylene (PTFE) conduit (Group A) and polyethylene-terephthalate (Dacron) conduit (Group B). RESULTS: The patient population included 105 patients: Group A had 80 patients, and Group B had 25 patients. The two groups were similar in major clinical and procedural variables, including conduit size and Nakata index. Eighteen patients (Group A: one [1.25%]; Group B: 17 [68%]) had conduit occlusion or severe stenosis requiring intervention after a mean 46.9±35months after the operation. The percentage of patients in Group A who were free of conduit obstruction at 3, 5, and 10 years was 100%, 100%, and 96%, respectively, whereas these figures were 68%, 52%, and 35% in Group B (log-rank <0.000). Conduit re-intervention was associated with an increased risk of overall mortality after primary intervention (p<0.004). Dacron tube was found to be an independent risk factor for mid-term stenosis or obstruction (hazard ratio, 62.9; 95% CI, 8.2-482.2; p=0.000). CONCLUSION: Dacron conduit for TCPC surgery was associated with a higher risk of obstruction and need for early re-intervention compared with PTFE conduit. Surgical or percutaneous re-interventions for conduit obstruction increased the risk of late mortality.

Outcomes of Right Ventricular Outflow Tract Reconstruction for Children with Persistent Truncus Arteriosus: A 10-Year Single-Center Experience.

The purpose of this report is to assess the mid- and long-term outcomes of right ventricular outflow tract (RVOT) reconstruction for children with persistent truncus arteriosus. Between September 2006 and 2016, 105 patients with persistent truncus arteriosus (PTA) received surgical treatment at Shanghai Children's Medical Center. Direct right ventricle-pulmonary artery anastomosis (pulmonary artery pull-down) was performed in 51 patients; a left auricle or pericardial conduit was inserted between the RVOT and pulmonary artery as a connection in 17 patients; heterograft (bovine jugular vein or Gore-tex) conduits and homograft conduits were used in 30 and 7 cases, respectively, to connect the distal pulmonary and right ventricle outflow tract; and pulmonary valve reconstruction was performed in 38 patients using a Gore-tex monocusp. There were six in-hospital deaths and one delayed death 5 months after operation. After a mean follow-up of 55.8 ± 16.5 months (6-113 months), 19 patients underwent reoperation (3 with pulmonary patch enlargement, 14 with conduit replacement and 2 with aortic valve replacement) 10-89 months after the first operation, with 1 hospital death. The actuarial survival rates were 94.2, 93.3 and 93.3% at 1, 5 and 10 years, respectively. Freedom from reoperation was 98.0, 87.8 and 82.7% at 1, 5 and 10 years, respectively. The follow-up variables included echocardiography, chest radiography, cardiac CT and cardiac function. At the last examination, most of the patients exhibited an improvement of New York Heart Association functional class from III or IV preoperatively to I or II at follow-up. Surgical treatment for PTA has an acceptable survival rate and satisfactory outcomes. Most patients exhibited an improvement in cardiac function during follow-up. Aortic arch deformity, truncal valvular regurgitation and long cardiopulmonary bypass time were regarded as risk factors for hospital mortality. Autologous tissue has a lower reoperation rate and better growth potential than extracardiac conduits. A monocusp valve effectively reduces pulmonary regurgitation in the early postoperative stage.

Correction of cortriatriatum sinister with classical Raghib's complex using an extracardiac conduit.

We present a 32-year-old patient with cortriatriatum sinister with Raghib's complex (a left persistent superior vena cava draining into the left atrium with an absent coronary sinus and an atrial septal defect [ASD]) who underwent successful surgical correction with excision of the cortriatriatum, closure of the ASD, and establishing the drainage of the persistent left superior vena cava to the right atrium via interposition of an extracardiac 13-mm ringed polytetrafluoroethylene conduit.

Intermediate-Term Results After Extracardiac Conduit Fontan Palliation in Children and Young Adults with Single Ventricle Physiology-A Single-center Experience.

The Fontan operation and its modifications are currently the standard palliation in patients with single ventricle physiology. The advantages of extracardiac conduit Fontan operation (ECF) have previously been described. We evaluated the outcome of patients who underwent ECF operation at our center since the year 2000 to assess morbidity, mortality and New York Heart Association (NYHA) functional class in the current era. Medical records of 97 patients who underwent ECF operation from November 2000 till October 2013 were reviewed to determine the diagnosis, age at surgery, surgical technique, postoperative complications, NYHA class at last follow-up, echocardiographic parameters, and most recent Holter monitor results. The median age at surgery was 3.4 years with 4 total deaths until last follow-up (hospital mortality was 1 %, and mortality after hospital discharge was 3 %). Seventy-eight of the 97 patients (80 %) underwent fenestrated Fontan surgery. Median duration of follow-up was 3.9 years (IQR 0.2-12.2 years). At the latest follow-up, 62 patients (67 %) were determined to be in NYHA class I, 25 patients (27 %) in NYHA class II, and 6 (6 %) patients in NYHA class III, and the median oxygen saturation was 92 % (IQR 86-96). There were 15 patients with history of preoperative arrhythmias and 6 of them required pacemaker placement at the time of surgery. One patient developed ectopic atrial tachycardia, and 1 patient had clinical thromboembolism on follow-up. Systolic function of the single ventricle by transthoracic echocardiogram at the latest follow-up was described as normal in 77 patients (83 %), fair in 15 patients (16 %), and poor in 1 patient (1 %). The results of our study show that patients who undergo extracardiac conduit Fontan operation in the modern era may have significantly less morbidity and mortality when compared to earlier years.

Creation of a transcatheter fenestration in children with failure of Fontan circulation: Focus on extracardiac conduit connection.

OBJECTIVES: We report our experience with a transcatheter technique to bypass the lung and to thus improve single-ventricle preload and reduce venous congestion in Fontan patients. BACKGROUND: In the absence of a dedicated power source to serve the pulmonary circulation and a significantly elevated transpulmonary pressure gradient, fenestration of the Fontan circulation is an option to improve hemodynamics in patients by relieving excessive systemic venous pressure. METHODS AND RESULTS: From 2005 to 2011, 22 transcatheter fenestrations were performed without any major complications in 19 patients (median age 3.2 years, interquartile range (IQR) 2.7-3.7 years)) with failing Fontan circulation and exceeding systemic venous pressure. In 16 patients, the procedure was performed for acute postoperative failure 1-24 days after surgery. After perforation of the conduit and atrial wall by a Brockenbrough needle and gradual balloon dilation, premounted stents were expanded to create a diabolo configuration with flaring stent edges, leaving a slight but definitive central waist. The procedure resulted in regression of pleural effusions and a significant decrease in systemic venous pressure. Clinical improvement was observed in 16 of the 19 treated patients. Follow-up demonstrated sustained fenestration in 85% of treated patients for at least 24 months. CONCLUSION: Transcatheter creation of a Fontan fenestration is a safe approach despite the anatomic gap between the extracardiac conduit cavity and the atrial wall. Stent implantation allows defining the diameter of the fenestration, reduces spontaneous occlusion, and ensures sustained clinical improvement.

Does the External Pericardial Lateral Tunnel Fontan Pathway Enlarge to Accommodate Somatic Growth? A Preliminary Analysis.

Objectives: An ideal Fontan pathway should be capable of adapting to changes in circulatory demands. The external pericardial lateral tunnel Fontan (EPLTF) is constructed of viable, autologous tissue and may be capable of changing in size. We investigated the ability of the EPLTF to enlarge with increasing physiologic demands of somatic growth. Methods: Retrospective review of echocardiographic images for patients with a minimum of five years follow-up after EPLTF. Serial echocardiographic measurements of the EPLTF pathway were obtained at three distinct locations: the inferior vena cava junction with the EPLTF, midsection of the EPLTF, and cross-sectional area of the EPLTF visualized in a four-chamber view. Body surface area (BSA) was calculated at the time of each echocardiographic measurement. Changes in echocardiographic measurements over time were analyzed and compared with changes in BSA. Results: A total of 332 echocardiographic studies from 38 patients were reviewed. Significant enlargement of the EPLTF pathway is observed at the inferior vena caval junction (P < .001), midsection (P < .01), and cross-sectional area (P < .001). Repeated measures correlation between pathway measurements and BSA is highly significant (P < .001). Conclusions: The EPLTF pathway enlarges over time in correlation with increasing BSA. Further research is needed to define ideal pathway size, differentiate normal physiologic growth from pathologic enlargement, and correlate changes with clinical outcomes.

Alarming rate of liver cirrhosis after the small conduit extracardiac Fontan: A comparative analysis with the lateral tunnel.

BACKGROUND: The association between the prevalence of cirrhosis and the types of Fontan operations remains unclear. METHODS: We conducted a retrospective chart review of 332 patients who underwent the Fontan procedure at our institution. Four patients who underwent the atriopulmonary connection Fontan were excluded from the analysis. Patients who had intracardiac-extracardiac conduit (126) between 1989 and 2021 were pooled with those having extracardiac conduit (ECC) (134). The 260 patients who underwent the ECC and the 68 patients who had the lateral tunnel (LT) Fontan constitute the core of the study. RESULTS: Median age at the Fontan procedure was 23.7 months (interquartile range [IQR], 20.8-32.6) in the LT group, compared with 28.8 months (IQR, 24.6-39.5) in the ECC group (P < .01). The median follow-up was 14.8 years (IQR, 12.5-16.5) in the LT group and 7 years (IQR, 2.8-10.4) in the extracardiac conduit group. During the follow-up period, 3 patients (4.4%) with LT and 17 patients (6.5%) with ECC (11 patients with 16 mm or less conduit size) were diagnosed with cirrhosis. The prevalence of cirrhosis at 1, 5, 10, and 15 years was 0%, 0%, 0%, and 4.4% in the LT group, respectively, and 0%, 0.9%, 7.7%, and 29.8% in the ECC group (P < .01) Rates of mortality, Fontan revision, Fontan takedown, transplant, and complications were comparable between the 2 groups. CONCLUSIONS: The extracardiac conduit Fontan seems to be associated with faster development of cirrhosis.

Virtual surgery to predict optimized conduit size for adult Fontan patients with 16-mm conduits.

OBJECTIVES: Recent evidence suggests that conduits implanted in Fontan patients at the age of 2-4 years become undersized for adulthood. The objective of this study is to use computational fluid dynamic models to evaluate the effect of virtual expansion of the Fontan conduit on haemodynamics and energetics of the total cavopulmonary connection (TCPC) under resting conditions and increased flow conditions. METHODS: Patient-specific, magnetic resonance imaging-based simulation models of the TCPC were performed during resting and increased flow conditions. The original 16-mm conduits were virtually enlarged to 3 new sizes. The proposed conduit sizes were defined based on magnetic resonance imaging-derived conduit flow in each patient. Flow efficiency was evaluated based on power loss, pressure drop and resistance and thrombosis risk was based on flow stagnation volume and relative residence time (RRT). RESULTS: Models of 5 adult patients with a 16-mm extracardiac Fontan connection were simulated and subsequently virtually expanded to 24-32 mm depending on patient-specific conduit flow. Virtual expansion led to a 40-65% decrease in pressure gradient across the TCPC depending on virtual conduit size. Despite improved energetics of the entire TCPC, the pulmonary arteries remained a significant contributor to energy loss (60-73% of total loss) even after virtual surgery. Flow stagnation volume inside the virtual conduit and surface area in case of elevated RRT (>20/Pa) increased after conduit enlargement but remained negligible (flow stagnation <2% of conduit volume in rest, <0.5% with exercise and elevated RRT <3% in rest, <1% with exercise). CONCLUSIONS: Virtual expansion of 16-mm conduits to 24-32 mm, depending on patient-specific conduit flow, in Fontan patients significantly improves TCPC efficiency while thrombosis risk presumably remains low.

Numerical simulation of the cavopulmonary connection flow with conduit stenoses of varying configurations.

The circulation in the total cavopulmonary connection (TCPC) is a low-energy system which operation and efficiency are subjected to multiple factors. Some retrospective studies report that the abnormal narrowing of vessels in the system, i.e. stenosis, is one of the most dangerous geometric factors which can result in heart failure. In the present study, the effect of varying extracardiac conduit (ECC) stenosis on the hemodynamics in a surrogate TCPC model is investigated using high-fidelity numerical simulations. The efficiency of the surrogate TCPC model was quantified according to the power loss, relative perfusion in lungs and the percentage of conduit surface area with abnormally low and high wall shear stress for venous flow. Additionally, the impact of respiration and asymmetry in the stenosis geometry to the system was examined. The results show that the flow in the TCPC model exhibits pronounced unsteadiness even under the steady initial boundary conditions, while the uneven pulmonary flow distribution and the presence of the ECC stenosis amplify the chaotic nature of the flow. Energy efficiency of the system is shown to strongly correlate with amount of vortical structures in the model and their range of scales. Finally, the study demonstrates that the presence of respiration in the model adds to perturbations in the flow which causes increase in the power loss. Results obtained in the study provide valuable insights on how the ECC stenosis effect the flow in the surrogate TCPC model under different flow conditions.

Extracardiac conduit adequacy along the respiratory cycle in adolescent Fontan patients.

OBJECTIVES: Adequacy of 16-20mm extracardiac conduits for adolescent Fontan patients remains unknown. This study aims to evaluate conduit adequacy using the inferior vena cava (IVC)-conduit velocity mismatch factor along the respiratory cycle. METHODS: Real-time 2D flow MRI was prospectively acquired in 50 extracardiac (16-20mm conduits) Fontan patients (mean age 16.9 ± 4.5 years) at the subhepatic IVC, conduit and superior vena cava. Hepatic venous flow was determined by subtracting IVC flow from conduit flow. The cross-sectional area (CSA) was reported for each vessel. Mean flow and velocity was calculated during the average respiratory cycle, inspiration and expiration. The IVC-conduit velocity mismatch factor was determined as follows: Vconduit/VIVC, where V is the mean velocity. RESULTS: Median conduit CSA and IVC CSA were 221 mm2 (Q1-Q3 201-255) and 244 mm2 (Q1-Q3 203-265), respectively. From the IVC towards the conduit, flow rates increased significantly due to the entry of hepatic venous flow (IVC 1.9, Q1-Q3 1.5-2.2) versus conduit (3.3, Q1-Q3 2.5-4.0 l/min, P < 0.001). Consequently, mean velocity significantly increased (IVC 12 (Q1-Q3 11-14 cm/s) versus conduit 25 (Q1-Q3 17-31 cm/s), P < 0.001), resulting in a median IVC-conduit velocity mismatch of 1.8 (Q1-Q3 1.5-2.4), further augmenting during inspiration (median 2.3, Q1-Q3 1.8-3.0). IVC-conduit mismatch was inversely related to measured conduit size and positively correlated with conduit flow. The normalized IVC-conduit velocity mismatch factor during expiration and the entire respiratory cycle correlated with peak VO2 (r = -0.37, P = 0.014 and r = -0.31, P = 0.04, respectively). CONCLUSIONS: Important blood flow accelerations are observed from the IVC towards the conduit in adolescent Fontan patients, which is related to peak VO2. This study, therefore, raises concerns that implanted 16-20mm conduits have become undersized for older Fontan patients and future studies should clarify its effect on long-term outcome.

Haemodynamic performance of 16-20-mm extracardiac Goretex conduits in adolescent Fontan patients at rest and during simulated exercise.

OBJECTIVES: To date, it is not known if 16-20-mm extracardiac conduits are outgrown during somatic growth from childhood to adolescence. This study aims to determine total cavopulmonary connection (TCPC) haemodynamics in adolescent Fontan patients at rest and during simulated exercise and to assess the relationship between conduit size and haemodynamics. METHODS: Patient-specific, magnetic resonance imaging-based computational fluid dynamic models of the TCPC were performed in 51 extracardiac Fontan patients with 16-20-mm conduits. Power loss, pressure gradient and normalized resistance were quantified in rest and during simulated exercise. The cross-sectional area (CSA) (mean and minimum) of the vessels of the TCPC was determined and normalized for flow rate (mm2/l/min). Peak (predicted) oxygen uptake was assessed. RESULTS: The median age was 16.2 years (Q1-Q3 14.0-18.2). The normalized mean conduit CSA was 35-73% smaller compared to the inferior and superior vena cava, hepatic veins and left/right pulmonary artery (all P < 0.001). The median TCPC pressure gradient was 0.7 mmHg (Q1-Q3 0.5-0.8) and 2.0 (Q1-Q3 1.4-2.6) during rest and simulated exercise, respectively. A moderate-strong inverse non-linear relationship was present between normalized mean conduit CSA and TCPC haemodynamics in rest and exercise. TCPC pressure gradients of ≥1.0 at rest and ≥3.0 mmHg during simulated exercise were observed in patients with a conduit CSA ≤ 45 mm2/l/min and favourable haemodynamics (<1 mmHg during both rest and exercise) in conduits ≥125 mm2/l/min. Normalized TCPC resistance correlated with (predicted) peak oxygen uptake. CONCLUSIONS: Extracardiac conduits of 16-20 mm have become relatively undersized in most adolescent Fontan patients leading to suboptimal haemodynamics.

Preoperative N-terminal pro-brain natriuretic peptide is associated with Fontan outcomes.

OBJECTIVE: The role of preoperative N-terminal pro-brain natriuretic peptide level in patient outcomes after the Fontan operation remains unclear. METHODS: The medical records of all patients who underwent their first Fontan operation from June 2011 to October 2019 in our tertiary referral pediatric cardiac center were retrospectively reviewed. Preoperative hemodynamic factors and N-terminal pro-brain natriuretic peptide were analyzed to test the association of mortality and morbidity. RESULTS: We enrolled 110 patients (men/women 62/48; median age, 4.1 [3.4, 5.8] years; median follow-up period, 4.28 [2.31, 6.71] years). Almost all operations were extracardiac conduits (98.2%). Primary outcomes of death, Fontan takedown, and heart transplantation were observed in 9 patients (8.2%). Abnormal ventricular contractility, elevated preoperative pulmonary artery pressure, high pulmonary vascular resistance index, and high log10 N-terminal pro-brain natriuretic peptide level were associated with poor outcomes. SECONDARY OUTCOMES: atrioventricular valve regurgitation moderate or greater, elevated pulmonary artery pressure, high pulmonary vascular resistance index, and high log10 N-terminal pro-brain natriuretic peptide level were associated with rehospitalization due to heart failure. Multivariable Cox regression analysis revealed that log10 N-terminal pro-brain natriuretic peptide was the only significant predictor of all primary and secondary outcomes. A scoring system including factors of pulmonary artery pressure, pulmonary vascular resistance index, and N-terminal pro-brain natriuretic peptide was established, and the risk stratification is associated with outcomes after the Fontan operation. CONCLUSIONS: High preoperative N-terminal pro-brain natriuretic peptide was associated with poor outcomes after the Fontan operation.

A catheter-based interventional strategy redirects hepatic vein flows after Fontan procedure in left isomerism to treat severe hypoxemia.

Pulmonary arteriovenous malformations after the Kawashima procedure causing severe hypoxemia are treated by Fontan surgery that redirects hepatic venous blood to the pulmonary circulation. Alignment of the hepatic venous conduit toward both pulmonary arteries is crucial for their regression. Persistent hypoxemia due to nonregressed malformations in one lung often warrants a repeat surgery to redirect hepatic venous flows. Catheter-based redirection of Fontan flows is not commonly performed as metallic stents and devices may predispose to thrombus formation in the circuit. This report highlights a patient with persistent arteriovenous malformations in the left lung leading to severe disabling hypoxemia that was managed in the catheterization laboratory with an innovative strategy to redirect Fontan flows toward the affected left lung.

A novel procedure of puncture to access the pulmonary venous atrium in complex congenital heart disease with surgical correction.

BACKGROUND: In complex congenital heart disease, supraventricular arrhythmia develops long term after surgical repair. The arrhythmia could have pharmacological tolerance and sometimes be fatal. We report our experiences with puncturing tough or calcified surgical repair material to access the pulmonary venous atrium for the purpose of the management of arrhythmia in complex congenital heart disease with surgical correction. METHODS: From June 2016, subsequent 9 patients underwent the procedure. Their age at the procedure ranged from 11 to 43 years old (median 26.4 years old). Surgical procedures were Mustard procedure (XenomedicaⓇ) in 6, lateral tunnel total cavo-pulmonary connection with autologous pericardium in 2, and extra-cardiac total cavo-pulmonary connection with expanded polytetrafluoroethylene (ePTFE) tube in 1. RESULTS: Multi-planar reconstruction imaging by cardiac computed tomography was done for making plans before the procedures. Under intracardiac echocardiography guidance, an 8 French steerable sheath was perpendicularly adjusted to target objects. The sharpened edge of 0.014 inch guide wire penetrated with gentle forward force. Subsequently, the puncture site was dilated from a small balloon to a large one step by step. In all patients, penetration was successfully completed. Catheter ablation was achieved in 8 patients and a pacemaker was implanted through the re-canalized superior caval vein in 1 patient. No complications were recorded. CONCLUSION: The trans-catheter puncture of the synthetic or calcified material is safe and feasible, although careful planning is required with imaging. A steerable sheath could easily be controlled to the make appropriate angle to the target object for preventing slippage and conveying effective force.

Serial assessment of somatic and cardiovascular development in patients with single ventricle undergoing Fontan procedure.

BACKGROUND: The palliation of patients with single ventricle (SV) undergoing Fontan procedure led to improved long-term survival but is still limited due to cardiovascular complications. The aim of this study was to describe the somatic and cardiovascular development of Fontan patients until adolescence and to identify determining factors. METHODS: We retrospectively assessed somatic growth, vascular growth of pulmonary arteries, and cardiac growth of the SV and systemic semilunar valve from 0 to 16 years of age using transthoracic echocardiography. The Doppler inflow pattern of the atrioventricular valve was quantified by E-, A-wave and E/A ratio. All data were converted to z-scores and analyzed using linear mixed effect models to identify associations with age at Fontan procedure, gender, and ventricular morphology. RESULTS: 134 patients undergoing Fontan procedure at a median age of 2.4 (IQR 2.12 to 2.8) years were analyzed. A catch-up of somatic growth after Fontan procedure until school age was found, with lower body height and weight z-scores in male patients and patients with systemic right ventricles. An early time of Fontan procedure was favorable for somatic growth, but not for vascular growth. Cardiac development indicated a decrease of SV end-diastolic diameter z-score until adolescence. Despite a trend towards normalization, E-wave and E/A ratio z-scores were diminished over the entire period. CONCLUSIONS: There is a catch-up growth of somatic, vascular and cardiac parameters after Fontan procedure, which in our cohort depends on the time of Fontan procedure, ventricular morphology, and gender. Beside other factors, diastolic function of the SV remains altered.