Current treatment options for the Failing Fontan Circulation

The Fontan operation was introduced in 1968. For congenital malformations where biventricular repair is not suitable, the Fontan procedure has provided a long-term palliation strategy with improved outcome compared to the initially developed procedures. Despite these improvements, several complications merely as a result of a failing Fontan circulation (including myocardial dysfunction, arrhythmias, increased pulmonary vascular resistance, protein losing enteropathy, hepatic dysfunction, plastic bronchitis and thrombo-embolism) will limit life-expectancy in this patient cohort. This review provides an overview of the most common complications of the Fontan circulation and the currently available treatment options.

Plastic Bronchitis—A Serious Rare Complication Affecting Children Only after Fontan Procedure?

Background: Plastic bronchitis (PB) may occur not only in children following palliative Fontan procedure but also in those without underlying heart disease. We aim to assess the clinical course, therapeutic measures, outcome, and follow-up of PB in children with congenital heart disease (CHD) and children without cardiac problems. Methods: This retrospective case series assessed children with PB admitted to hospital between 2015 and 2019. Parents or guardians of patients were contacted by e-mail or telephone between September 2017 and June 2019 to enquiry about recurrence of PB and strategy of treatment. The diagnosis of PB was based on the expectoration (spontaneous or during bronchoscopy) of endobronchial plugs. Results: This study delineated the clinical, histological, and laboratory features of plastic bronchitis in children following Fontan procedure (Group A) and in those without heart defects (Group B, non-CHD children). The main symptoms were cough accompanied by dyspnea, and hypoxemia with a decrease in oxygen saturation, often leading to acute respiratory failure. In children with CHD, the first episode of PB occurred at a relatively young age. Although chronic, i.e., lasting more than 3 weeks, inhaled therapy was implemented in both groups of patients, the recurrences of PB were observed. The mean time to PB recurrence after the first episode in Group A was longer than that in Group B (1.47 vs. 0.265 years, p = 0.2035). There was no re-episode with recurrence of PB in 3 cases out of 10 in total in Group A (30%) and 1 case out of 4 in total in Group B (25%). While the majority of children in Group A usually developed bronchial casts on the right side, the patients in Group B (without CHD) suffered from bronchial casts located only on the left side. Conclusions: Despite many similarities, clinical, histological, and laboratory studies in the children with plastic bronchitis after Fontan’s surgery and in children without heart defects suggest that there are differences in the course of the disease in patients without CHD, such as a more advanced age of the first episode of PB, the location of plastic casts on the left side, and a stronger role of inflammatory factors and mechanisms. Further research is needed to understand the pathophysiology of PB and choose the most appropriate therapy.

Properties of Plasma Clots in Adult Patients Following Fontan Procedure: Relation to Clot Permeability and Lysis Time—Multicenter Study

Objectives: thromboembolic complications are a major cause of morbidity and mortality following Fontan (FO) surgery. It is also well established that altered FO circulation results in systemic complications, including liver and endothelium damage. We sought to evaluate whether dysfunctions of these sources of hemostatic factors may result in changes of fibrin clot properties. Methods: a permeation coefficient (Ks) and clot lysis time (CLT) were assessed in 66 FO patients, aged 23.0 years [IQR 19.3–27.0], and 59 controls, aged 24.0 years [IQR 19.0–29.0]. Ks was determined using a pressure-driven system. CLT value was measured according to assay described by Pieters et al. Endothelium and liver-derived hemostatic factors along with liver function parameters were evaluated. The median time between FO operation and investigation was 20.5 years [IQR 16.3–22.0]. Results: FO patients had lower Ks (p = 0.005) and prolonged CLT (p < 0.001) compared to that of controls. Ks correlated with CLT (r = −0.28), FVIII (r = −0.30), FIX (r = −0.38), fibrinogen (r = −0.41), ALT (r = −0.25), AST (r = −0.26), GGTP (r = −0.27) and vWF antigen (r = −0.30), (all p < 0.05). CLT correlated with the time between FO operation and investigation (r = 0.29) and FIX (r = 0.25), (all p < 0.05). After adjustment for potential cofounders, TAFI antigen and GGTP were independent predictors of reduced Ks (OR 1.041 per 1% increase, 95% CI 1.009–1.081, p = 0.011 and OR 1.025 per 1 U/L increase, 95% CI 1.005–1.053, p = 0.033, respectively). Protein C and LDL cholesterol predicted prolonged CLT (OR 1.078 per 1% increase, 95% CI 1.027–1.153, p = 0.001 and OR 6.360 per 1 μmol/L increase, 95% CI 1.492–39.894, p = 0.011, respectively). Whereas elevated tPA was associated with lower risk of prolonged CLT (OR 0.550 per 1 ng/mL, 95% CI 0.314–0.854, p = 0.004). GGTP correlated positively with time between FO surgery and investigation (r = 0.25, p = 0.045) and patients with abnormal elevated GGTP activity (n = 28, 42.4%) had decreased Ks, compared to that of the others (5.9 × 10−9 cm2 vs. 6.8 × 10−9 cm2, p = 0.042). Conclusion: our study shows that cellular liver damage and endothelial injury were associated with prothrombotic clot phenotype reflected by Ks and CLT.

Failures of the Fontan System in Univentricular Hearts and Mortality Risk in Heart Transplantation: A Systematic Review and Meta-Analysis

The Fontan procedure (FP) is the standard surgical treatment for Univentricular heart diseases. Over time, the Fontan system fails, leading to pathologies such as protein-losing enteropathy (PLE), plastic bronchitis (PB), and heart failure (HF). FP should be considered as a transitional step to the final treatment: heart transplantation (HT). This systematic review and meta-analysis aims to establish the risk of death following HT according to the presence of FP complications. There was a total of 691 transplanted patients in the 18 articles, immediate survival 88% (n = 448), survival from 1 to 5 years of 78% (n = 427) and survival from 5.1 to 10 years of 69% (n = 208), >10 years 61% (n = 109). The relative risk (RR) was 1.12 for PLE (95% confidence interval [CI] = 0.89–1.40, p = 0.34), 1.03 for HF (0.7–1.51, p = 0.88), 0.70 for Arrhythmias (0.39–1.24, p= 0.22%), 0.46 for PB (0.08–2.72, p = 0.39), and 5.81 for CKD (1.70–19.88, p = 0.005). In patients with two or more failures, the RR was 1.94 (0.99–3.81, p = 0.05). After FP, the risk of death after HT is associated with CKD and with the presence of two or more failures.

Perioperative Management of Staged Palliation Surgery for Functional Univentricle Hearts: A Literature Review

Around 3-4 children born with congenital heart diseases have univentricular hearts, where the prognosis of univentricular hearts is poor in the past, with a survival rate of less than 50% during the first year and 10% during the first ten years of life. Based on a literature search, current advances in perioperative management of neonates with complex congenital heart diseases have increased their survival rate by 85%. To aid cardiothoracic surgeons worldwide, this comprehensive literature review will focus on the perioperative management of staged palliation surgery for functional univentricular hearts, considering current trends as well as how we do it in our centre. Our review article specifially discusses perioperative strategies regarding surgical considerations, current techniques, to deal with overshunting and undershunting during the first stage of palliation surgery. This article also gives an overview on when a patient is suitable to go through with the next stage of the procedure, which is the implementation of a bidirectional cavopulmonary shunt or the Hemi-Fontan procedure. Lastly, this article gives a comprehensive approach regarding perioperative strategies of the Fontan procedure, which include patient criteria, current surgical techniques, postoperative management, as well as the use of anticoagulants after the Fontan procedure.

Mid Term Results of Fenestrated Intra-Extracardiac Fontan Procedure: Insights, Experiences and Expectations

Background: Intraextracardiac Fontan procedure aimed to combine the advantages of lateral tunnel and extracardiac conduit modifications of the original technique. Herein, we present our experience in our patients with intraextracardiac fenestrated Fontan Procedure. Methods: A retrospective analysis was performed in order to evaluate intraextracardiac fenestrated Fontan patients between 2014 and 2021. Seventeen patients were operated on with a mean age and body weight of 9.1 ± 5.5 years and 28.6 ± 14.6 kg. Results: Sixteen patients (94%) were palliated as univentricular physiology with hypoplasia of one of the ventricles. One patient (6%) with well-developed two ventricles with double outlet right ventricle and complete atrioventricular septal defect had straddling of the chordae prohibiting a biventricular repair. All of the patients had cavopulmonary anastomosis prior to Fontan completion, except one case. Fenestration was performed in all cases. Postoperative mean pulmonary artery pressures and arterial oxygen saturation levels at follow up were 10 ± 2.4 mmHg and 91.3 ± 2.7 %, respectively. Mean duration of pleural drainage was 5.4 ± 2.3 days. All of the fenestrations are patent at a mean follow up period of 4.8 ± 7.7 years, except one case. Any morbidity and mortality were not encountered. Conclusions: The mid-term results of intraextracardiac fenestrated Fontan procedure are encouraging. This procedure may improve the results in a patient population who should be palliated as univentricular physiology, especially in cases with complex cardiac anatomy.

Management Considerations of Hodgkin Lymphoma for Patients with Fontan Physiology

While treatment protocols for Hodgkin Lymphoma (HL) are well established, there is no literature available to guide therapy or estimate prognosis for patients with Fontan physiology who develop HL. The physiology of a Fontan procedure can result in the inability to tolerate chemotherapy toxicities, supportive care and infection. We present a series of 3 patients with Fontan physiology who were treated for HL and discuss their clinical course and treatment.