The impact of pulmonary artery size on midterm outcomes after nonfenestrated Fontan operationWe sought to identify the impact of pulmonary artery size on outcomes after nonfenestrated total cavopulmonary connection. In a subgroup of patients with right-sided bidirectional cavopulmonary shunt, the impact of each branch pulmonary artery size was individually determined.
Noninvasive surrogates are poor predictors of liver fibrosis in patients with Fontan circulationPatients with Fontan circulation exhibit a high incidence of liver fibrosis and cirrhosis. Transient elastography (TE) and the enhanced liver fibrosis (ELF) test have proven useful as noninvasive surrogate markers of liver fibrosis for other chronic liver diseases. We evaluated whether TE and the ELF score can predict the degree of liver fibrosis in patients with Fontan circulation.
Preoperative N-terminal pro-brain natriuretic peptide is associated with Fontan outcomesThe role of preoperative N-terminal pro-brain natriuretic peptide level in patient outcomes after the Fontan operation remains unclear.
Diastolic inflow is associated with inefficient ventricular flow dynamics in Fontan patientsThis study used cardiac magnetic resonance imaging to evaluate flow characteristics and ventricular hemodynamics for children with single right (hypoplastic left heart syndrome) and single left (hypoplastic right heart syndrome) systemic ventricle anatomy after Fontan palliation compared with normal biventricular controls.
Biventricular conversion after Fontan completion: A preliminary experienceTo assess the feasibility and outcomes of biventricular conversion following takedown of Fontan circulation.
Factors associated with mortality or transplantation versus Fontan completion after cavopulmonary shunt for patients with tricuspid atresiaTricuspid atresia with normally related great vessels (TA) is considered the optimal substrate for the Fontan pathway. The factors associated with death or transplantation after cavopulmonary shunt (CPS) are underappreciated. We aimed to determine factors associated with CPS–Fontan interstage death/transplantation versus transition to Fontan in TA.
Imposition of Fontan physiology: Effects on strain and global measures of ventricular functionWe sought to evaluate contractile function in single-ventricle patients before and after imposition of Fontan physiology.
Long-term outcomes of warfarin versus aspirin after Fontan surgeryBecause of the nature of the Fontan physiology, patients are at an increased risk of thromboembolic complications. As such, warfarin or aspirin is generally prescribed lifelong for thromboprophylaxis. This study aimed to compare long-term rates of cerebrovascular injury, thrombosis, bleeding, bone mineral density, and quality of life in people living with Fontan circulation receiving warfarin compared with aspirin.
Progression in Fontan conduit stenosis and hemodynamic impact during childhood and adolescenceTo characterize changes in Fontan conduit size over time and determine if cross-sectional area (CSA) affects cardiac output, pulmonary artery growth, and exercise capacity.
Long-term outcomes following Fontan takedown in Australia and New ZealandFontan takedown remains an option for the management of Fontan failure. We sought to evaluate early and late outcomes after Fontan takedown.
Protein-losing enteropathy and plastic bronchitis after the Fontan procedureProtein losing enteropathy and plastic bronchitis are severe complications in Fontan circulation, with 5-year survival ranging from 46% to 88%. We report risk factors and outcomes of protein losing enteropathy and plastic bronchitis in patients undergoing the Fontan.
A preoperative estimate of central venous pressure is associated with early Fontan failureEarly Fontan failure is a serious complication after total cavopulmonary connection, characterized by high central venous pressure, low cardiac output, and resistance to medical therapy. This study aimed to estimate postoperative central venous pressure in patients with total cavopulmonary connection using data routinely collected during preoperative assessment. We sought to determine if this metric correlated with measured postoperative central venous pressure and if it was associated with early Fontan failure.
Commentary: A 3-minute foray into the futureThe year is 2050. Freddy Jones is about to undergo a Fontan operation. Freddy is an unusual patient. Most blastocysts are genetically screened for hypoplastic left heart syndrome, and if detected, a developing patient undergoes either embryological epigenetic modification or fetal intervention, preventing or eliminating the disorder. These techniques are still not globally available, so Freddy was not screened. Thus, Freddy is managed with the older, 3-stage palliation. In preparation for the Fontan, Freddy undergoes cardiac magnetic resonance imaging with complete pressure mapping (diagnostic catheterization became obsolete by 2030).
Commentary: Man versus machine: Whose side are you on?Go is an ancient Chinese board game that is played today exactly as it was more than 3000 years ago.1 It is a game with simple rules, in which 2 players take turns putting black and white stones onto a flat piece of wood on which a grid is printed. To win, a player captures or surrounds more territories than the opponent. Despite its simplicity, Go is far more complex than chess, with possible moves and legal positions estimated to be greater than the number of atoms in the known universe. Go is a game more of intuition than anticipation or calculation.
Commentary: Yet another Fontan computational study—but this one has clayWhat does clay have to do with computational flow dynamics (CFD) and the personalized Fontan (herein referred to as the TCPC)? Loke and colleagues' response1 is that a surgeon-fashioned clay TCPC actually performed reasonably well and could reduce the computational time and money by serving as starting input for the CFD iterative process. With the availability of surgical modeling software, we don't fully understand the need for clay and haptic feedback but, must admit, find the use of clay kind of appealing—can't explain it, maybe it invokes pleasant childhood memories.
Role of surgeon intuition and computer-aided design in Fontan optimization: A computational fluid dynamics simulation studyCustomized Fontan designs, generated by computer-aided design (CAD) and optimized by computational fluid dynamics simulations, can lead to novel, patient-specific Fontan conduits unconstrained by off-the-shelf grafts. The relative contributions of both surgical expertise and CAD to Fontan optimization have not been addressed. In this study, we assessed hemodynamic performance of Fontans designed by both surgeon's unconstrained modeling (SUM) and by CAD.
Commentary: I don't like changeOkay, I will admit that I do not like to change. It is difficult to see that what you have done for years may not be the right way and then head in a different direction, whether with respect to medical treatment of a particular nature, in a relationship, or in practicing surgery for congenital heart disease. I think this is particularly true for surgical techniques, where there are very few randomized studies proving that one technique is better than another (actually, that's also true for relationships).
Fontan with lateral tunnel is associated with improved survival compared with extracardiac conduitThe study aim was to compare Fontan patients undergoing lateral tunnel (LT) versus extracardiac conduit (ECC) technique.
Management of the bad atrioventricular valve in Fontan…time for a changeSuccessful long-term outcome following Fontan procedure depends on numerous factors, including normal ventricular systolic and diastolic function, adequate pulmonary artery size and distribution, low pulmonary artery pressures and resistance, sinus rhythm, and a competent atrioventricular valve.
Commentary: Promise of personalized tissue-engineered vascular grafts for congenital heart surgeryVascular grafts and, more commonly, patches are commonly used in the repair of congenital heart defects. Non-autologous, circumferential vascular grafts have key shortcomings, such as the lack of growth potential and need for anticoagulation, that prohibit their universal adoption.1 Another shortcoming of grafts and patches is that tailoring of their shape and size before implantation is according to the surgeon's eye or crude measurements in 1 or 2 dimensions. Although this tailoring may be satisfactory for simple geometries, achieving the most efficient hemodynamic result for complex pathways and baffles in growing children is sometimes difficult, and the development of late obstruction may necessitate reoperation.
In vivo implantation of 3-dimensional printed customized branched tissue engineered vascular graft in a porcine modelThe customized vascular graft offers the potential to simplify the surgical procedure, optimize physiological function, and reduce morbidity and mortality. This experiment evaluated the feasibility of a flow dynamic–optimized branched tissue engineered vascular graft (TEVG) customized based on medical imaging and manufactured by 3-dimensional (3D) printing for a porcine model.
Commentary: Something made from nothing—impressive, but will it last?I congratulate Yeung and colleagues1 for their development of an elegant, sophisticated, and innovative technology and also commend their collaboration across multiple disciplines and institutions. The basic concept they promote is intuitively very appealing—use patient-specific anatomy, guided by computational fluid dynamics, to develop 3-dimensional (3D) vascular grafts tailored to a given patient's specific needs—in this particular case, the creation of bifurcated pulmonary artery grafts. The reader should look beyond the fact that both animals originally had normal anatomy, as I presume the computer-aided design phase would permit creation of any desired anatomy (for missing parts), which could then be modified to fit the patient's true anatomy.
Commentary: Why use the Y-graft?The Fontan procedure represents the last stage of surgical palliation for functional single-ventricle defects. As a staged operation in the current era, the Fontan procedure creates a pathway that directs inferior vena cava (IVC) blood flow into the lungs via the branch pulmonary arteries. Over time, a number of modifications of the Fontan procedure have been made, including an atriopulmonary connection, intra-atrial lateral tunnel, extracardiac conduit, and extracardiac Y-graft.
Commentary: Moderate atrioventricular valve regurgitation may be too much to bear for a single ventricleIn their editorial review in this issue of the Journal, Stephens and Dearani1 comment on the results of our retrospective series2 that assessed the incidence and impact of atrioventricular regurgitation in patients who had survived the Fontan operation. In our experience, more than half of the common atrioventricular valves and tricuspid valves were regurgitant or necessitated intervention before patients reached the age of 25 years (Figure 1).2 The existence of even moderate regurgitation was enough to more than double a patient's risk of circulatory failure, which for most meant death or transplantation.
Commentary: Cavopulmonary assist: Closing in on the white whale of single-ventricle palliationImproving the long-term survival and quality of life for patients with single-ventricle heart disease remains the single greatest unmet need in pediatric heart surgery and pediatric cardiology. Although the surgical outcomes of single-ventricle palliation have been celebrated and have steadily improved over time, the unsightly truth is that the Fontan circulation is a grossly abnormal circulatory configuration, which leads to a myriad of progressive, debilitating, and ultimately fatal medical problems that accumulate over time.