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Acute kidney injury (AKI) is a common complication following single ventricle congenital heart surgery. Data regarding AKI following Fontan conversion (FC) surgery are limited. This study evaluated the incidence, predictors of, and prognostic value of AKI following FC. Single-center retrospective cohort study, including consecutive FC patients from December 1994 to December 2016. Medical records were reviewed. AKI was classified into AKI-1/AKI-2/AKI-3 using Kidney Disease: Improving Global Outcomes criteria. Multivariable logistic regression identified risk factors for AKI≥2. Chi-square and 2-sample t-tests assessed associations between AKI≥2 and postoperative outcomes. Mid-term heart-transplant-free survival among AKI0-1 vs AKI2-3 groups was compared using Kaplan-Meier curves and log-rank test. We included 139 FC patients: age at FC 24 (25th-75th, 19-31) years; 81% initial atrio-pulmonary Fontan; follow-up 8.3 ± 5.3 years following FC. Post-FC, 63 patients (45%) developed AKI (AKI-1 = 37 [27%]; AKI-2 = 10 [7%]; AKI-3 = 16 [11%]). AKI recovered by hospital discharge in 86%, 80%, and 19% of patients with AKI-1/AKI-2/AKI-3, respectively. Independent risk factors for AKI≥2 included older age (OR 1.07, 95%CI 1.01-1.15; P = 0.027); ≥3 prior sternotomies (OR = 6.11; 95%CI = 1.59-23.47; P = 0.009); greater preoperative right atrial pressure (OR 1.19; 1.02-1.38; P = 0.024), and prior catheter ablation procedure (OR 3.45; 1.17-10.18; P = 0.036). AKI≥2 was associated with: longer chest tube duration (9 [5-57] vs 7 [3-28] days; P = 0.01); longer mechanical ventilation time (2 [1-117] vs 1 [1-6] days; P = 0.01); greater need for dialysis (31% v s0%; P < 0.001); and longer postoperative length of stay (18 [8-135] vs 10 [6-58] days; P < 0.001). AKI 2-3 patients had worse mid-term heart-transplant-free survival. Half of the patients undergoing FC develop AKI. AKI 2-3 is associated with worse early postoperative outcomes and reduced mid-term transplant-free survival following FC. Knowledge of AKI predictors may allow for improved FC risk stratification, patient selection, and perioperative management in this high-risk population. [ABSTRACT FROM AUTHOR]

• Atrial fibrosis is a key pathological change of atrial myopathy. • Progression of atrial fibrosis is common long after classic Fontan surgery. • Atrial fibrosis was more common in the persistent/permanent atrial tachyarrhythmia group. • Atrium enlargement was found to correlate with atrial fibrosis. • Long-term Fontan circulation contributed to atrial fibrosis progression. The progression of atrial fibrosis long after Fontan surgery is unclear. This study aimed to evaluate the degree of atrial fibrosis long after the classic Fontan procedure and to investigate the factors associated with atrial fibrosis. We obtained atrial free wall specimens resected at Fontan conversion from 43 patients (Fontan group) and studied the degree of atrial fibrosis, along with its association with atrial tachycardia/fibrillation (AT/AF) and other clinical parameters, compared with those of the control group without heart disease (n=6). The time after the initial Fontan procedure was 19.9 (15.9–25.3) years. Atrial fibrosis (%) was more common in the Fontan group than in the control group [24.3 (20.9–35.0)% vs. 6.2 (5.6–7.5)%, p <0.001]. The severity of atrial fibrosis was mild in 16% (n=7), moderate in 54% (n=23), and severe in 30% (n=13) of cases. Atrial fibrosis (%) was more common in the persistent/permanent AT/AF group than in the no AT/AF (p <0.001) and paroxysmal AT/AF (p <0.001) groups. The maximum atrial diameter on computed tomography (CT) (mm) significantly correlated with atrial fibrosis (%) (r=0.52, p <0.001). The maximum diameter of the right atrium (≥75 mm) on CT was a significant risk factor for severe atrial fibrosis on multivariate logistic analysis (hazard ratio=10.22, 95% confidence interval=1.04–254.8, p =0.04). Atrial fibrosis was prominent long after classic Fontan surgery, especially in patients with non-paroxysmal AT/AF and dilated right atrium. [Display omitted] [ABSTRACT FROM AUTHOR]

Open in new tab Download slide Open in new tab Download slide OBJECTIVES Fontan patients are known to suffer from clinical attrition over the years, which has been characterized as Fontan failure. We sought to evaluate the clinical outcomes of such Fontan patients undergoing surgical management in a 25-year, single-centre experience. METHODS A retrospective single-centre analysis of patients undergoing surgical treatment for failing Fontan between 1995 and 2020, including any reoperations when ventricular function was preserved, or a heart transplant (HTx), when ventricular contractility was impaired. We analysed survival, indications for surgery and early and late complication rates. RESULTS We collected 30 patients (mean age 24.7 years) who required surgery after a mean time of 19.3 years from the original Fontan procedure: Fontan conversion in 21 (70%, extracardiac conduit in 19, lateral tunnel in 2), a HTx in 4 (13.3%) and other reoperations in 5 (16.7%). The most common indications for surgery were tachyarrhythmias (63.3%) and severe right atrial dilatation (63.3%). Overall survival at the 1-, 5-, 10- and 20-year follow-up examinations were 75.9% [95% confidence interval (CI): 91.4–60.4%], 75.9% (95% CI: 91.4–60.4%), 70% (95% CI: 78–52%) and 70% (95% CI: 78–52%), respectively. The most frequent complications were postoperative tachyarrhythmias (50%) and late Fontan-associated liver disease (56.5%). HTx and Fontan conversion provided comparably good outcomes compared to other reoperations (P  = 0.022). CONCLUSIONS Surgery for failing Fontan can be performed effectively with overall good long-term survival. However, early and late morbidities are still a significant burden. Because other reoperations performed when patients presented with contraindications for a HTx have carried high mortality, close clinical follow-up is mandatory, and an earlier indication for Fontan conversion or a HTx is advisable to optimize outcomes. [ABSTRACT FROM AUTHOR]

A 38-year-old man with a functional single ventricle secondary to hypoplastic left heart syndrome presented with exertional fatigue. His last palliation was an intra-atrial conduit Fontan procedure. Comprehensive evaluation showed elevated liver enzyme values and a small, calcified conduit. Successful conversion to a nonfenestrated extracardiac conduit Fontan was performed with normalization of his liver enzyme values., Competing Interests: Dr Said has served as a consultant for Artivion, Abbott, and Japanese Organization for Medical Device Development (JOMDD). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2024 The Authors.)

Objectives: Patients with univentricular hearts who require permanent pacing systems typically require placement of epicardial leads. It is frequently difficult to find a position with good thresholds due to epimyocardial fibrosis or fat. The goal of the study is to assess the progression of capture thresholds (CT), sensing parameters (P waves and R waves), and impedances (imp) of steroid eluting epicardial pacing leads in young adults who underwent Fontan conversion and a pacemaker implant. Methods: All patients undergoing Fontan conversion in two institutions were retrospectively identified. Demographic data, congenital heart defects, pacing leads used, and pacing parameters were analyzed at implant, at 6 weeks and 12 months after implant. Results: Twenty patients were identified (twelve males); mean age at conversion was 24.9 ± 5.4 years (range 18-35). Epicardial bipolar steroid eluting leads were used. The site of implant both in the atria and the ventricles varied depending on the parameters. At implant, mean atrial and ventricular impedances were 617 ± 171 O and 1061 ± 771 O, respectively, mean P wave amplitude was 2 ± 0.7 mV, and mean R wave amplitude was 12.5 ± 7.7 mV. Mean CT was 1.7 ± 0.8 V at 0.5 ms for the atrium and 2.2 ± 1.2 V at 0.5 ms for the ventricle. Ventricular CT and impedance showed an improvement within the first 12 months after implant, with four patients having a decrease in threshold of more than 2 V. Conclusion: In patients undergoing Fontan conversion, implant ventricular CT and impedances are frequently higher than expected but typically improve during follow-up. Acceptance of higher initial threshold values may be a potential strategy in this patient population. [ABSTRACT FROM AUTHOR]

• Fontan conversion can be suggested in asymptomatic patients. • Fontan conversion with the Maze procedure may prevent future tachyarrhythmia. • The outcome is compatible with that of primary total cavopulmonary connection. • The Maze procedure should be reserved for those with a history of tachyarrhythmia. • Sinus node dysfunction can occur after the prophylactic Maze procedure. : The indication of Fontan conversion (FC) from atriopulmonary connection (APC) to total cavopulmonary connection (TCPC) is unclear. We sought to analyze the mid-term outcome of prophylactic and therapeutic Fontan conversion compared with that of primary TCPC. : Patients with a univentricular heart who underwent cardiac catheterization at >18 years of age between July 2005 and July 2019 were included and divided into three groups: symptomatic APC patients who underwent therapeutic FC (t-FC, n = 13), asymptomatic APC patients after prophylactic FC (p-FC, n = 15), and patients who had primary TCPC procedure (pTCPC, n = 24). : The mean last follow up was at the age of 32.0 ± 7.8, 26.8 ± 3.8, and 27.3 ± 7 years (p = 0.07) in t-FC, p-FC, and pTCPC, respectively. There was no late death. All of t-FC and 12 (80%) of p-FC cases underwent concomitant arrhythmic surgery. Consequently, five and four patients in t-FC and p-FC groups required pacemaker implantations mostly due to sinus node dysfunction. Thromboembolism was seen in 2 cases in both t-FC (15%) and p-FC (13%), and 1 case in pTCPC (4%) (p = 0.50). The last cardiac catheterization was performed at the age of 29.5 ± 8.5, 24.6 ± 3.8, and 26.3 ± 7.1 years (p = 0.11) in t-FC, p-FC, and pTCPC patients, respectively. There was no significant difference in central venous pressure, aortic pressure, and cardiac index among the three groups. There was no late supraventricular tachyarrhythmic event seen in t-FC and p-FC, whereas two patients in pTCPC had newly developed atrial flutter. : FC is a safe and feasible procedure to bring APC patients back onto the same track of primary TCPC patients in terms of hemodynamics as well as arrhythmia. The antiarrhythmic procedure should be carefully chosen because sinus node dysfunction can frequently occur and FC itself would reduce the risk of arrhythmia. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide Open in new tab Download slide OBJECTIVES The aim of this study was to identify the long-term therapeutic effect of total cavopulmonary connection (TCPC) conversion with an extracardiac conduit. METHODS Between 1991 and 2014, 36 patients underwent TCPC conversion with an extracardiac conduit. Half of these patients were diagnosed with tricuspid atresia or its variant. The left ventricle was dominant in 26 patients (72.2%). Median age at conversion and interval from initial Fontan operation to conversion were 24.1 years (interquartile range 18.9–29.2) and 17.8 years (15.4–20.9), respectively. Surgical cryoablation was concomitantly performed in 32 patients (88.9%). Cardiac catheter examination was performed preoperatively (36 patients, 100%) and at 1 year (31 patients, 86%), 5 years (25 patients, 69%) and 10 years (13 patients, 36%) after TCPC conversion. Symptom-limited treadmill exercise with expired gas analysis was performed preoperatively (32 patients, 88.9%) and at 1 year (27 patients, 75.0%), 5 years (20 patients, 55.6%) and 10 years (12 patients, 33.3%) after conversion. RESULTS All patients received follow-up; the mean follow-up period was 8.2 ± 4.8 years. Actuarial survival rate, protein-losing enteropathy-free survival rate and rate of survival with sinus rhythm maintenance at 10 years were 79.2%, 67.8% and 48.5%, respectively. The survival curve declined steeply when the duration of Fontan circulation exceeded 25 years. New cases of protein-losing enteropathy developed postoperatively in 2 patients. Permanent pacemakers were implanted in 12 patients (33%), but atrial tachyarrhythmia was not sustained in any of the remaining patients. Pulmonary arterial pressure (11.0 ± 3.1 to 9.5 ± 3.6 mmHg, P  = 0.003), pulmonary vascular resistance (2.1 ± 0.7 to 1.3 ± 0.5 WU/m2, P  < 0.0001) and cardiac index (2.0 ± 0.3 to 2.9 ± 0.6 l/min/m2, P  < 0.0001) significantly improved from preoperative evaluation to 1 year after the conversion, and these improvements were maintained during the entire follow-up period. Peak oxygen uptake remained unchanged from the preoperative evaluation (49.7 ± 11.5% predicted) to 1 year (52.5 ± 12.0%), 5 years (56.2 ± 9.6%) and 10 years (51.2 ± 9.4%) after conversion (P  = 0.19). CONCLUSIONS Owing to its anti-arrhythmic effect and Fontan pathway recruitment effect, TCPC conversion with an extracardiac conduit prevented the natural decline of exercise tolerance that is seen in classic Fontan patients. [ABSTRACT FROM AUTHOR]

Recent reports suggested that cardiopulmonary bypass (CPB) time is one of the risk factors for postoperative complications after Fontan conversion. Although Fontan conversion may be performed for the patients with hepatic fibrosis after initial Fontan procedure, there is no predictive indicator regarding the liver function associated with hemostasis which can affects CPB time. Thirty-one patients who underwent Fontan conversion using the same surgical procedure (extracardiac conduit conversion with right atrium exclusion) were enrolled. In multivariate analyses including age at Fontan conversion, interval from initial Fontan to conversion, hemodynamic data such as right atrial pressure, ventricular end-diastolic pressure, and cardiac index, hepatic data such as platelet count, prothrombin time international normalized ratios, serum total bilirubin, hyaluronic acid levels, five known indices for hepatic fibrosis (Forns Index, APRI, FIB4, FibroIndex, and MELD-XI), and liver stiffness measured by ultrasound elastography, only the Forns Index remained independently associated with the CPB time (P < 0.01) and blood transfusions (plasma transfusions and platelet concentrations: P < 0.01 for both). The cutoff level for Forns Index to predict the prolonged CPB time (exceeding 240 min) was 4.85 by receiver-operating characteristic curve (area under the curve 0.823, sensitivity 76.9%, and specificity 72.2%). Three patients with Forns Index > 7.0 had poor outcomes with long CPB time and massive blood transfusions in contrast with the other 28 patients. In conclusion, Forns Index could serve as a practical predictor of CPB time and is associated with blood transfusion volume in Fontan conversion. [ABSTRACT FROM AUTHOR]

Patients with a functionally univentricular heart who have had an atriopulmonary Fontan are at risk for atrial dilatation, atrial arrhythmias, and progressive circulatory failure. Between 1994 and 2018, we performed 149 Fontan conversions with arrhythmia surgery and epicardial pacemaker placement at Ann & Robert H. Lurie Children's Hospital of Chicago. This operation converts the atriopulmonary Fontan to an extracardiac Fontan that improves hemodynamics and controls the atrial arrhythmias. Operative mortality during that time was 2%, and freedom from death or heart transplant at 10 years is 84%. For properly selected patients, Fontan conversion improves both survival and quality of life. Patients with an atriopulmonary Fontan constitute an eroding population, as they face many comorbidities and have a decreased life expectancy without treatment; therefore, all patients with an atriopulmonary Fontan should be evaluated for this procedure. [ABSTRACT FROM AUTHOR]

Background The Fontan palliation is associated with numerous complications during long-term. The Fontan conversion operation has been advocated as an option to avoid some of these problems by converting classical Fontan types to modern forms of the circulation. Early mortality of Fontan conversion, however, remains unclear as available reports include limited numbers of patients and the results are heterogeneous. Methods We reviewed all original articles from 1994 to 2016 reporting Fontan conversion operations. Reports were analysed with specific reference to patient demographics, patient number, concomitant arrhythmia surgery, pacemaker implantation and early mortality. Results Overall, 37 Fontan conversion studies with a total of 1182 patients were analysed, including 35 single-centre studies and 2 registers. In the 35 single-centre studies the average age at the time of conversion was 21.6 years (range 10.2–30.9 years). Concomitant arrhythmia operation was performed in 71.6% of patients and concomitant pacemaker implantation procedure was performed in 59.3% of patients. Early mortality varied greatly between publications ranging from 0 to 21%. Based on a random and a fixed effect model mean mortality was 5.3% and 6.2%, respectively. Lower mortality was observed in series including younger patients at the time of conversion (average age < 20 years, 4.6%) and in the highest volume centre (1.4%). Conclusion Fontan conversion carries a substantial mortality risk. However, results vary between centres. Overall, the combination with arrhythmia surgery seems to be associated with lower early mortality especially when patients are referred at an earlier age and are treated at highly experienced centres. [ABSTRACT FROM AUTHOR]

Objective To review our experience of patients with an atrio-pulmonary Fontan circulation to determine their long-term outcomes. Methods and results A retrospective analysis of long-term follow-up data using the Australia and New Zealand Fontan Registry was performed. There were 215 patients surviving hospital discharge after an atrio-pulmonary Fontan completion. A total of 163 patients were alive at latest follow-up, with 52 deaths. Twelve patients had required heart transplantation and 95 had Fontan failure (death, transplantation, Fontan takedown, Fontan conversion, severe systemic ventricular dysfunction or NYHA ≥ 3). Twenty-eight year freedom from death, death and transplantation and Fontan failure were 69% (95% CI 61–78%), 64% (95% CI 56–74%) and 45% (95% CI 36–55%) respectively. One hundred and thirty patients developed atrial arrhythmias. Freedom from arrhythmia at 28 years post Fontan was 22.9% (95% CI: 15.1–30.8). Development of arrhythmia increased the likelihood of death (HR:2.97, 95%CI 1.50–5.81; p = 0.002), death and heart transplantation (HR:3.11, 95%CI 1.64–5.87; p < 0.001) and Fontan failure (HR:4.78 95%CI 2.95–7.74; p < 0.001). There were 42 patients who had thromboembolic events, of which only 12 were therapeutically anti-coagulated. Two-thirds of the surviving patients (86/126) with an intact atrio-pulmonary Fontan were regularly reviewed. Patients receiving follow-up care with general cardiologists without specialised training were more likely to face Fontan failure than those managed by cardiologists with specialist training in congenital heart disease (HR: 1.94, 95% CI 1.16–3.24; p = 0.02). The majority of the surviving patients (81/86) remained physically active and almost two-thirds (54/86) were currently employed. Conclusion Two-thirds of the patients who underwent a classical atrio-pulmonary Fontan are still alive 3 decades later. The majority are affected by the burden of arrhythmias but remain functionally active today. These challenging patients should only receive follow-up care from cardiologists with specialised training. [ABSTRACT FROM AUTHOR]

Background To determine if Fontan conversion (FC) resulted in improvement in exercise capacity (EC), and to determine the role of cardiopulmonary exercise test (CPET) in risk stratification of patients undergoing FC. Methods A retrospective review of patients who underwent CPET prior to FC at Mayo Clinic from 1994 to 2014. The patients who also underwent post-operative CPET were selected for the analysis of improvement in EC defined as 10% increase in baseline peak oxygen consumption (VO 2 ). Results 75 patients CPET prior to FC; mean age 24 ± 6 years; 44 males (59%); and 51 (68%) were in NYHA III/IV prior to FC. Pre-operative peak VO 2 was 15.5 ± 3.4 ml/kg/min. A comparison of pre- and post-FC CPET data was performed using 42 patients (56%) that underwent CPET after FC. Improvement in EC occurred in 18 of 42 patients (43%). Baseline peak VO 2 > 14 ml/kg/min was associated with improved EC (hazard ratio [HR] 1.85; P = .02). Improvement in New York Heart Association (NYHA) class occurred in 12 (67%) patients with improved EC vs 2 (8%) without improved EC. Improvement in NYHA class was more likely to occur in patients with improved EC compared to those without improvement EC (odds ratio 4.11, P = .01). There were 10 (13%) perioperative deaths, and baseline peak VO 2 ≤ 14 ml/kg/min was predictive of perioperative mortality (HR 3.74; P < .001). Conclusions Baseline peak VO 2 was predictive of perioperative survival, and improvement in EC. Performance on CPET in failing Fontan patients might be a useful clinical parameter in determining appropriate timing of FC. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the benefits of a strategy of early Fontan conversion. METHODS: Using the Australia and New Zealand Fontan Registry, retrospective analysis of their long-term follow-up data was performed. RESULTS: Between 1990 and 2014, a total of 39 patients underwent surgical conversion in 6 centres at a median age of 23.8 years (IQR: 19.3–28.2), 18.7 ± 5.0 years post-Fontan. One centre tended to perform conversion earlier: interval since first documented arrhythmia 2.9 ± 4.0 vs 4.0 ± 4.2 years, average NYHA Class 2 ± 0.4 vs 3 ± 0.9 (P = 0.008), mean number of preop anti-arrhythmics 1 ± 0.4 vs 2 ± 0.6 (P = 0.05). Two patients underwent conversion to an extracardiac conduit only, while 36 had concomitant right atrial cryoablation, of which 16 also had pacemaker implantation. Nine patients suffered major cardiac-related complications (7 low output syndrome, 3 ECMO, 3 acute renal failure, one stroke) (2/17 from the early conversion centre and 7/22 of the others; P = 0.14). Four patients died in hospital (10.3%) and 4 late after a median of 0.9 years [95% confidence interval (CI): 0.5–1] after conversion. An additional 2 patients needed transplantation at 1 and 8.8 years after conversion, respectively. The 10-year freedom from heart transplantation was 86% (95% CI: 51–97%). Outcomes from the centre with an early conversion strategy were significantly better: 8-year freedom from death or heart transplantation was 86% (95% CI: 53–96) vs 51% (95% CI: 22–74; log-rank P = 0.007). Eight additional patients required pacemaker implantation and 5 had arrhythmia recurrence. CONCLUSIONS: Fontan conversion is associated with lasting survival outcomes up to 10 years after conversion. A strategy of surgical conversion at earlier stage of failure may be associated with better survival free from transplantation. [ABSTRACT FROM AUTHOR]

Most single ventricle patients undergo Fontan procedure earlier in current era. However, optimal timing of Fontan completion after an intermediate staging surgery is controversial. We present children who had Fontan surgeries younger than 3 years of age comparing the data with older patients. Between 2000 and 2013, 45 patients with functional single ventricle underwent extracardiac total cavopulmonary connection (TCPC) using GORE-TEX conduit at a single institution. Children were divided into group A (age < 36 months; n = 15) and group B (age ≥ 36 months; n = 30), and retrospectively reviewed. Median follow-up was 2.9 [interquartile range (IQR) 2-4.4] years. There were two hospital deaths and one late death (all in group B, p = 0.286). One TCPC was taken down in group A. The median intensive care unit and hospital stay were 90 (IQR 46-140) h and 21 (IQR 16-33) days for group A versus 65 (IQR 45-115) h and 29 (IQR 20.8-38.5) days for group B, respectively ( p = 0.322 and p = 0.057). Ventricular ejection fraction and GORE-TEX conduit size were similar in both groups. The time of chest drain stay was significantly lower in group A (median 12 days, IQR 7-22) than in group B (22 days, IQR 16-32.5) ( p = 0.014). Extracardiac TCPC can be performed earlier with good intermediate results. Earlier Fontan procedure might be advantageous for reducing chest drains stay. [ABSTRACT FROM AUTHOR]

Background Facing longer follow-up of patients after Fontan operation, Fontan conversion was proposed to treat failing Fontan circulation. We reviewed our patients who reached up to 42 years of age. Methods Fifteen consecutive patients underwent Fontan conversion to extracardiac conduit combined with biatrial maze procedure between October 2006 and January 2014.Mean age at conversion was 30.9 ± 5.6 years and mean interval from primary Fontan palliation to conversion was 23.2 ± 3.3 years. Results There was one early death. Ten of 14 survivors were extubated within 24 hours, and 11 were discharged from intensive care unit (ICU) within 7 days. The impaired left ventricular function, presented in four patients prior to surgery, improved from EF 43.8 to 54.8% (p = 0.02). During follow-up time of 3.6 ± 2.3 years after conversion, there was no late death and no reoperation. Two patients developed recurrent atrial arrhythmia. Older age at Fontan procedure, lower left ventricular function, higher New York Heart Association (NYHA) class, and anatomy other than tricuspid atresia emerged as risk factors for longer ICU stay. Conclusion Fontan conversion improved the functional status in almost all patients. A concomitant maze procedure effectively eliminated atrial arrhythmia. This procedure provides a benefit even for older patients if all additional cardiac pathologies are addressed. [ABSTRACT FROM AUTHOR]

A mechanical blood pump specifically designed to increase pressure in the great veins would improve hemodynamic stability in adolescent and adult Fontan patients having dysfunctional cavopulmonary circulation. This study investigates the impact of axial-flow blood pumps on pressure, flow rate, and energy augmentation in the total cavopulmonary circulation ( TCPC) using a patient-specific Fontan model. The experiments were conducted for three mechanical support configurations, which included an axial-flow impeller alone in the inferior vena cava ( IVC) and an impeller with one of two different protective stent designs. All of the pump configurations led to an increase in pressure generation and flow in the Fontan circuit. The increase in IVC flow was found to augment pulmonary arterial flow, having only a small impact on the pressure and flow in the superior vena cava ( SVC). Retrograde flow was neither observed nor measured from the TCPC junction into the SVC. All of the pump configurations enhanced the rate of power gain of the cavopulmonary circulation by adding energy and rotational force to the fluid flow. We measured an enhancement of forward flow into the TCPC junction, reduction in IVC pressure, and only minimally increased pulmonary arterial pressure under conditions of pump support. [ABSTRACT FROM AUTHOR]

OBJECTIVES We investigated the mid-term surgical results of Fontan conversion with antiarrhythmias surgery and permanent pacemaker implantation, which were complications of a previous Fontan operation. METHODS From January 1996 to November 2011, we performed Fontan conversion in 31 of 260 Fontan cases (M:F = 17:14, mean age = 19.0 years). The Fontan conversion from atriopulmonary connection (APC) to extracardiac conduit (ECC) was performed in 20 patients, APC to lateral tunnel in 5 and lateral tunnel to ECC in 6. The clinical outcomes and improvements of arrhythmias were analysed. The types of arrhythmias included atrial flutter in 21 patients, atrial fibrillation with flutter in 4 patients and junctional tachycardia in 3 patients. RESULTS Twenty-six patients (83.9%) required antiarrhythmia surgery (isthmus cryoablation = 9, right-sided maze = 13, bilateral maze = 4). In addition, 23 patients (74.2%) received a permanent pacemaker. The New York Heart Association functional class (NYHA Fc) was statistically improved after the surgery during the 6.5-year median follow-up duration (preoperative NYHA Fc = 1.77, postoperative NYHA Fc = 1.13, n = 15, P = 0.001). There were 4 late mortalities. Actuarial 5-year survival was 90.0 ± 5.5%. And freedom from arrhythmia was 91.8 ± 5.5%, at 5 years. Normal sinus rhythm was maintained in 12 patients (38.7%), pacing-dependent rhythm in 10 patients (32.3%) and intermittent pacing-dependent rhythm in 4 patients (12.9%). CONCLUSIONS Fontan conversion with antiarrhythmia surgery and permanent pacemaker implantation is safe and improves the clinical outcome and arrhythmias. [ABSTRACT FROM AUTHOR]

Intraatrial-conduit Fontan is considered a modification of both extracardiac and lateral-tunnel Fontan. In this study, the patient-specific hemodynamic performance of intraatrial-conduit and lateral-tunnel Fontan with fenestration, considered as conversion templates, was investigated based on the authors' patient cohort. Pulsatile computational fluid dynamics simulations were performed using patient-specific models of intraatrial-conduit and lateral-tunnel Fontan patients. Real-time 'simultaneous' inferior and superior vena cava, pulmonary artery, and fenestration flow waveforms were acquired from ultrasound. Multiple hemodynamic performance indices were investigated, with particular focus on evaluation of the pulsatile flow performance. Power loss inside the lateral-tunnel Fontan appeared to be significantly higher than with the intraatrial-conduit Fontan for patient-specific cardiac output and normalized connection size. Inclusion of the 4-mm fenestration at a 0.24 L/min mean flow resulted in a lower cavopulmonary pressure gradient and less time-averaged power loss for both Fontan connections. Flow structures within the intraatrial conduit were notability more uniform than within the lateral tunnel. Hepatic flow majorly favored the left lung in both surgical connections: conversion from lateral-tunnel to intraatrial-conduit Fontan resulted in better hemodynamics with less power loss, a lower pressure gradient, and fewer stagnant flow zones along the conduit. This patient-specific computational case study demonstrated superior hemodynamics of intraatrial-conduit Fontan over those of lateral-tunnel Fontan with or without fenestration and improved performance after conversion of the lateral tunnel to the intraatrial conduit. The geometry-specific effect of the nonuniform hepatic flow distribution may motivate new rationales for the surgical design. [ABSTRACT FROM AUTHOR]

Abstract: The Fontan operation has offered many children with single ventricle congenital heart disease survival. As technology, operative technique, critical care medicine have improved, more of these children are surviving into adulthood. Unfortunately, as the number of survivors increases, so does the recognition of the long-term consequences of Fontan anatomy and physiology. Hopefully, novel techniques will emerge to treat or prevent these complications, and provide for prolonged survival in this challenging patient population. [Copyright &y& Elsevier]

Abstract: Objective: In the long-term period after Fontan operation, atrial arrhythmia was one of the important factors to decide the postoperative quality of life. We reviewed the impact of Fontan conversion with arrhythmia surgery and pacemaker therapy. Methods: Thirty-eight patients underwent Fontan conversion using extracardiac conduit from 1992, and 22 patients with atrial arrhythmia underwent maze procedure simultaneously using cryoablation or radiofrequency ablation and epicardial DDD pacemaker implantation and 16 patients had regular ‘sinus’ rhythm before Fontan conversion. Mean follow-up period was 52 months. Pre- and postoperative clinical course were analyzed. Average weight, age at Fontan conversion, and years after first Fontan operation were 49.0kg, 25.8 years old, 14.7 years, respectively. Nineteen percent of patients were in New York Heart Association class I (NYHA I), and 74% of patients were in NYHA II, and 7% were in NYHA III, respectively. Results: Except three early deaths, actual survival rate at 1 year and 5 years were 80% and 64%, respectively. In survivors, 80% of the patients obtained regular heart rhythm including artificial pacemaker rhythm, although only 43% of the patients had regular ‘sinus’ rhythm before the Fontan conversion. Postoperative average cardiothoracic ratio and oxygen saturation (SpO2) were 50% and 94%, and 74% of patients were in NYHA I and 26% were in NYHA II, respectively, after Fontan conversion. Conclusions: Mid-term results of Fontan conversion with arrhythmia surgery and pacemaker therapy were acceptable. Restoration of regular rhythm might improve the postoperative NYHA status and the activity of the daily life. [Copyright &y& Elsevier]

This study evaluated the performance of an intravascular, percutaneously-inserted, axial flow blood pump in an idealized total cavopulmonary connection (TCPC) model of a Fontan physiology. This blood pump, intended for placement in the inferior vena cava (IVC), is designed to augment pressure and blood flow from the IVC to the pulmonary circulation. Three different computational models were examined: (i) an idealized TCPC without a pump; (ii) an idealized TCPC with an impeller pump; and (iii) an idealized TCPC with an impeller and diffuser pump. Computational fluid dynamics analyses of these models were performed to assess the hydraulic performance of each model under varying physiologic conditions. Pressure-flow characteristics, fluid streamlines, energy augmentation calculations, and blood damage analyses were evaluated. Numerical predictions indicate that the pump with an impeller and diffuser blade set produces pressure generations of 1 to 16 mm Hg for rotational speeds of 2000 to 6000 rpm and flow rates of 1 to 4 L/min. In contrast, for the same flow range, the model with the impeller only in the IVC demonstrated pressure generations of 1 to 9 mm Hg at rotational speeds of 10 000 to 12 000 rpm. Influence of blood viscosity was found to be insignificant at low rotational speeds with minimal performance deviation at higher rotational speeds. Results from the blood damage index analyses indicate a low probability for damage with maximum damage index levels less than 1% and maximum fluid residence times below 0.6 s. The numerical predictions further indicated successful energy augmentation of the TCPC with a pump in the IVC. These results support the continued design and development of this cavopulmonary assist device. [ABSTRACT FROM AUTHOR]

To provide a viable bridge-to-transplant, bridge-to-recovery, or bridge-to-surgical reconstruction for patients with failing Fontan physiology, we are developing a collapsible, percutaneously inserted, magnetically levitated axial flow blood pump to support the cavopulmonary circulation in adolescent and adult patients. This unique blood pump will augment pressure and thus flow in the inferior vena cava through the lungs and ameliorate the poor hemodynamics associated with the univentricular circulation. Computational fluid dynamics analyses were performed to create the design of the impeller, the protective cage of filaments, and the set of diffuser blades for our axial flow blood pump. These analyses included the generation of pressure–flow characteristics, scalar stress estimations, and blood damage indexes. A quasi-steady analysis of the diffuser rotation was also completed and indicated an optimal diffuser rotational orientation of approximately 12°. The numerical predictions of the pump performance demonstrated a pressure generation of 2–25 mm Hg for 1–7 L/min over 3000–8000 rpm. Scalar stress values were less than 200 Pa, and fluid residence times were found to be within acceptable ranges being less than 0.25 s. The maximum blood damage index was calculated to be 0.068%. These results support the continued design and development of this cavopulmonary assist device, building upon previous numerical work and experimental prototype testing. [ABSTRACT FROM AUTHOR]

Currently, no long-term mechanical bridge-to-transplant or bridge-to-recovery therapeutic alternative exists for failing single ventricles. A blood pump that would augment pressure in the cavopulmonary circulation is needed, and would lead to a reduction in elevated systemic venous pressure, and improve cardiac output. Thus, we are developing a collapsible, percutaneously inserted, axial flow blood pump to support the cavopulmonary circulation in adult patients with a failing single ventricle physiology. This collapsible axial flow pump is designed for percutaneous positioning. The outer protective cage will be designed with radially arranged filaments as touchdown surfaces to protect the vessel wall from the rotating components. This study examined the geometric characteristics of the protective cage of filaments and the impeller through the development and numerical analysis of 13 models. A blood damage analysis was also performed on selected geometric models to assess the probability of blood trauma. All models demonstrated an acceptable hydraulic performance by delivering 2–6 L/min at a rotational speed of 6000–10 000 rpm and generating pressure rise of 5–20 mm Hg. Expected trends in the hydraulic performance of the pump models were found. This study represents the initial first design phase of the impeller and protective cage of filaments. Validation of these flow and performance predictions will be completed in the next round of experimental testing with blood bag evaluation. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Hemodynamic abnormalities and refractory atrial arrhythmias in patients late after the Fontan operation result in significant morbidity and mortality. We reviewed our experience with Fontan conversion and concomitant arrythmia surgery. Methods: Between January 1996 and February 2004, 16 patients underwent Fontan conversion and arrhythmia surgery. Mean age at the initial Fontan operation was 5.1±3.5 (range: 2–15) years and mean age at Fontan conversion was 17.0±5.8 (range: 6–30). The initial Fontan operations were atriopulmonary connections in 14 patients, extracardiac lateral tunnel in 1, and intracardiac lateral tunnel in 1. The types of arrhythmia included atrial flutter in 10 patients and atrial fibrillation in 3. Fontan conversion operation was performed with intracardiac lateral tunnel in 5 patients and extracardiac conduit in 11. Arrhythmia surgery included isthmus cryoablation in 10 patients and right-sided maze in 3. Results: There has been no mortality. At Fontan conversion operation, 7 patients required permanent pacemaker. All patients have improved to New York Heart Association class I or II. With a mean follow-up of 26.9±30.6 (range:1–87) months, 16 patients had sinus rhythm, 2 patients had transient atrial flutter which was well controlled, and 2 patients required permanent pacemaker during follow-up. Conclusions: Fontan conversion with concomitant arrhythmia surgery and permanent pacemaker placement is safe, improves New York Heart Association functional class, and has a low incidence of recurrent arrhythmias. In most patients, concomitant permanent pacemakers are needed. [Copyright &y& Elsevier]

Although Fontan conversion combined with cardiac resynchronization therapy appears to be an effective surgical solution for the management of failing Fontan circulation with refractory atrial arrhythmia and cardiac dysfunction due to dyssynchronous ventricular wall motion, limited data are available on the mid- to long-term results of this treatment. We report our successful experience with Fontan conversion combined with cardiac resynchronization therapy in a male patient with failing Fontan circulation who showed favourable outcomes 5 years after the operation. [ABSTRACT FROM AUTHOR]

The article offers information on the development of dilated atrial connection by atriopulmonary Fontan which leads to atrial arrhythmias and low cardiac output from inefficient venous flow. Topics discussed include quality of life and transplant-free survival of the patients; improvement in the outcomes of the operation; and development of ventricular dysfunction or multisystem organ failure.

Background: The initial classic Fontan utilising a direct right atrial appendage to pulmonary artery anastomosis led to numerous complications. Adults with such complications may benefit from conversion to a total cavo-pulmonary connection, the current standard palliation for children with univentricular hearts., Methods: A single institution, retrospective chart review was conducted for all Fontan conversion procedures performed from July, 1999 through January, 2017. Variables analysed included age, sex, reason for Fontan conversion, age at Fontan conversion, and early mortality or heart transplant within 1 year after Fontan conversion., Results: A total of 41 Fontan conversion patients were identified. Average age at Fontan conversion was 24.5 ± 9.2 years. Dominant left ventricular physiology was present in 37/41 (90.2%) patients. Right-sided heart failure occurred in 39/41 (95.1%) patients and right atrial dilation was present in 33/41 (80.5%) patients. The most common causes for Fontan conversion included atrial arrhythmia in 37/41 (90.2%), NYHA class II HF or greater in 31/41 (75.6%), ventricular dysfunction in 23/41 (56.1%), and cirrhosis or fibrosis in 7/41 (17.1%) patients. Median post-surgical follow-up was 6.2 ± 4.9 years. Survival rates at 30 days, 1 year, and greater than 1-year post-Fontan conversion were 95.1, 92.7, and 87.8%, respectively. Two patients underwent heart transplant: the first within 1 year of Fontan conversion for heart failure and the second at 5.3 years for liver failure., Conclusions: Fontan conversion should be considered early when atrial arrhythmias become common rather than waiting for severe heart failure to ensue, and Fontan conversion can be accomplished with an acceptable risk profile.

Patients with single ventricle heart disease often undergo staged surgical palliation, ultimately resulting in Fontan anatomy and physiology. Long-term consequences include cirrhosis of the liver, protein-losing enteropathy, and premature death. Elevated central venous pressure and venous congestion transmitted to the abdominal viscera have been implicated in the aetiology of many of these complications. We present a novel operation directed at protecting the liver and intestines by excluding the splanchnic venous return from the Fontan pathway. Instead of exposure to elevated Fontan pressures, the liver and intestines will be exposed to lower common atrial pressures. We hope that this modification will minimise the abdominal complications of Fontan anatomy and physiology.

Plastic bronchitis is a rare, life-threatening condition characterized by the formation of mucofibrinous casts within the pulmonary bronchi. In patients with congenital heart disease, it is most frequently observed in single ventricular anatomies after Fontan palliation. The pathophysiology of plastic bronchitis remains unknown, and a consistently effective treatment strategy has yet to be identified. We report two cases of plastic bronchitis in patients with Fontan physiology. The first was treated with Fontan conversion and, despite encouraging short-term results, experienced recurrence of cast formation seven months postoperatively. The second underwent cardiac transplantation and has been free of bronchial casts for over one year. In addition, we explore the similarities between plastic bronchitis and protein-losing enteropathy, considering theories of their pathophysiologic mechanisms and reports of mutually effective treatment strategies. We propose that bronchial cast formation may result from the confluence of genetic makeup, inflammation, and the Fontan physiology and conclude that further investigation into therapies directed at these factors is merited.