Outcomes among adult survivors of total cavopulmonary Fontan palliation for single ventricle

ObjectiveThis tertiary centre study aims to identify factors associated with adverse outcomes in adult survivors with total cavopulmonary connection (TCPC) Fontan palliation for single ventricle.MethodsThis retrospective review of medical records identified adult (≥18 years) survivors of TCPC Fontan palliation who were followed at a single tertiary centre between 1 January 2000 and 1 July 2019. Adverse outcomes were defined as arrhythmia, pacemaker/implantable cardioverter defibrillator placement, liver cirrhosis, protein losing enteropathy, hospitalisation for heart failure, thromboembolic complication and/or death.Results160 adult TCPC patients met the inclusion criteria: 117 (73.1%) extracardiac and 43 (26.9%) lateral tunnel. The median (IQR) duration of follow-up since TCPC palliation was 17.5 (11.8–21.3) years. An adverse outcome occurred in 87 (54.4%) patients. Adverse outcome-free survival rates at 10, 20 and 25 years post TCPC were 89% (95% CI 82% to 93%), 60% (95% CI 50% to 69%) and 24% (95% CI 15% to 35%), respectively. On multivariate analysis, extracardiac Fontan (HR 2.21, 95% CI 1.20 to 4.08, p=0.011) was observed to be an independent risk factor for adverse outcomes after adjusting for age, race, morphology of the systemic ventricle and history of fenestration.ConclusionsIn this single-centre retrospective study of adult survivors of TCPC palliation, extracardiac Fontan was associated with an increased hazard for adverse outcomes. This finding could guide clinicians in developing risk modification strategies and management decisions to improve long-term outcomes in these patients.

Lumped parameter models for two-ventricle and healthy and failing extracardiac Fontan circulations

Fontan circulations are surgical strategies to treat infants born with single ventricle physiology. Clinical and mathematical definitions of Fontan failure are lacking, and understanding is needed of parameters indicative of declining physiologies. Our objective is to develop lumped parameter models of two-ventricle and single-ventricle circulations. These models, their mathematical formulations and a proof of existence of periodic solutions are presented. Sensitivity analyses are performed to identify key parameters. Systemic venous and systolic left ventricular compliances and systemic capillary and pulmonary venous resistances are identified as key parameters. Our models serve as a framework to study the differences between two-ventricle and single-ventricle physiologies and healthy and failing Fontan circulations.

Severe conduit stenosis in a patient with Fontan circulation with a Y-shaped Dacron conduit

Conduit stenosis is a major, albeit rare, complication following the Fontan palliation. A single-baffle conduit with polytetrafluoroethylene is widely used for an extracardiac type Fontan palliation. A polyethylene terephthalate conduit (Dacron) is sometimes used for the conduit when more flexibility is required. A Y-shaped conduit is rarely used, but it may reduce the energy loss and achieve better hepatic flow distribution. Data on the long-term patency and complications when using a Y-shaped Dacron conduit is lacking. We report a case of a severely stenotic Y-shaped Dacron conduit in a patient who underwent extracardiac Fontan palliation.

Fontan-Associated Anatomical Variants and Hepatic Fibrosis

Objective: We hypothesized that a relationship between post-Fontan hepatic fibrosis and anatomical variants might exist. Methods: Attempting to limit confounding variables, we analyzed data from living, stable, post-extracardiac Fontan patients who underwent cardiac catheterization and transvenous hepatic biopsy procedures between March 2012 and June 2020. Results: We identified 120 patients who met the inclusion criteria. Of the 120, 35 (29%) had pulmonary artery stents. For the 35 with pulmonary artery stents, the average total fibrosis score was 3.2 ± 1.9 and the fibrosis progression rate was 0.36 ± 0.33, and for those with no pulmonary artery stents, the total fibrosis score was 2.6 ± 1.8 and the fibrosis progression rate was 0.27 ± 0.33 ( P = .13 and P = .11, respectively). Of the 120, 65 had functional univentricles of right ventricular type. Of these 65, 27 had pulmonary artery stents. For the 27 with pulmonary artery stents, the average total fibrosis score was 3.4 ± 1.8 and the average fibrosis progression rate was 0.39 ± 0.30, and for the 38 without pulmonary artery stents, the average fibrosis score was 2.3 ± 1.5 and the average fibrosis progression rate was 0.23 ± 0.21 ( P = .01 for comparison of both values). Conclusions: This study’s findings suggest that a post-extracardiac Fontan with a functional univentricle of right ventricular type plus a pulmonary artery stent may have more advanced liver pathology than those without a pulmonary artery stent at similar Fontan duration years and ages at liver biopsy.

Off-pump extracardiac Fontan completion: Surgical technique and pitfalls

Completion of the extracardiac Fontan procedure is the final palliative stage for treating a functional single ventricle. It has been associated with a smaller incidence of atrial arrhythmias and more laminar flow in the Fontan pathway. We present our technique for the off-pump extracardiac Fontan procedure.