Design of an Experimental Mock Circulatory System for the Fontan Circulation

2010 ◽  
Author(s):  
John A. Chiulli ◽  
Timothy A. Conover ◽  
Richard S. Figliola ◽  
Tain-Yen Hsia
Keyword(s):  
Blood Vessels ◽  
Fontan Operation ◽  
Pulmonary Arteries ◽  
Intrathoracic Pressure ◽  
Venous Hypertension ◽  
Fontan Circulation ◽  
Patient Specific ◽  
Residual Pressure ◽  
Venous Flow ◽  
Mock Circulatory System

Each year, a small fraction of children are born with univentricular hearts, causing the lethal blue baby syndrome. Several preliminary operations are required to buy time until the child’s blood vessels grow to sufficient size. Once the child reaches an age of 3–5 years, the blood vessels have grown enough for the Stage 3 Fontan operation, in which the superior and inferior vena cavae are coupled directly to the pulmonary arteries in a cruciform junction [2,3]. After this operation, the heart is only pumping blood to the systemic circulation. Only residual pressure in the systemic veins and intrathoracic pressure change with respiration drive the flow into the lungs [5]. This circulation decreases the load on the heart, allowing the patients to survive with normal blood oxygen levels. This circulation decreases the load on the heart, allowing the patients to survive into their 20s and 30s. An aim of this study is to develop an experimental model of the Fontan circulation that can be readily adapted to simulate patient specific anatomies so as to assist in potential surgical decisions. Of interest is the study of chronic venous hypertension, a result of the Fontan circulation having no heart “vacuum” at the end of the vena cavae; it is known to cause liver failure. We also intend to examine the hypothesis of Hsia et al. [6] that decreasing sub-diaphragmatic venous flow reversal will improve functional outcome of the Fontan.

Experimentally Modeling Patient-Specific Fontan Circulations Including Respiration Effects Using a Mock Circulatory System

2011 ◽  
Author(s):  
John A. Chiulli ◽  
Timothy A. Conover ◽  
Sharmad S. Joshi ◽  
Richard S. Figliola ◽  
Tain-Yen Hsia
Keyword(s):  
Hepatic Vein ◽  
Heart Defects ◽  
Fontan Operation ◽  
Vena Cava ◽  
Circulatory System ◽  
Fontan Circulation ◽  
Flow Reversal ◽  
Patient Specific ◽  
Pulmonary Vascular Disease ◽  
Mock Circulatory System

The Fontan circulation is the result of a series of operations performed on children born with univentricular circulations (1). These congenital heart defects are uniformly fatal if left alone. After birth, an operation is performed to assure that the child receives enough blood flow to the lungs, but not too much in order to avoid pulmonary vascular disease. Once the child reaches 2–4 years of age, the child’s blood vessels are sufficiently large for the Fontan operation. The Fontan operation connects the great systemic veins directly to the pulmonary arteries, bypassing the right ventricle entirely. One method of the Fontan procedure, which is known as the total cavopulmonary connection (TCPC), achieves venous return to the pulmonary circulation without a ventricular power source. The load on the heart is reduced, and these patients can lead a normal life into adulthood; although late complications continue to prevent normal lifespan. One unique feature of the Fontan circulation is reliance of the inferior vena cava (IVC) flow on respiration, and flow reversal in the IVC and hepatic vein during expiratory phase of breathing (2). Hsia et al. (3) suggest that reducing flow reversal in the hepatic vein will improve the outcome of the Fontan operation. The goal of this study is to model experimentally the Fontan circulation for a variety of different patients using an adjustable mock circulatory system, which for the first time includes the influence of respiration.

Designing a Patient-Specific Paediatric Mock Circulatory System to Study the Norwood Circulation

2011 ◽  
Author(s):  
Giovanni Biglino ◽  
Silvia Schievano ◽  
Catriona Baker ◽  
Alessandro Giardini ◽  
Richard Figliola ◽  
...  
Keyword(s):  
Ductus Arteriosus ◽  
Pulmonary Arteries ◽  
Circulatory System ◽  
Innominate Artery ◽  
Systemic Circulation ◽  
Norwood Procedure ◽  
Patient Specific ◽  
Mock Circulatory System ◽  
Pulmonary Flow ◽  
Left Heart Syndrome

The Stage I of Fontan palliation for neonates with hypoplastic left heart syndrome, namely the Norwood procedure, aims to improve the flow of oxygenated blood in the systemic circulation while at the same time providing blood flow to the pulmonary circulation1. This surgical operation usually involves enlargement of the hypoplastic aorta by means of a patch, reconstruction of aortic coarctation and increase pulmonary flow. The latter point, at present, is achieved in three different ways: i) a Blalock-Taussig (BT) shunt from the innominate artery to the pulmonary artery, ii) an atrio-pulmonary shunt, referred to as Sano modification2 and iii) stenting the ductus arteriosus and banding the pulmonary arteries, referred to as “hybrid” Norwood3. In general, it is clear that the circulation following the Norwood procedure presents a very specific and complex arrangement.

Is the “Perfect Fontan” operation routinely achievable in the modern era?

2008 ◽  
Vol 18 (3) ◽  
pp. 328-336 ◽  
Author(s):  
James K. Kirklin ◽  
Robert N. Brown ◽  
Ayesha S. Bryant ◽  
David C. Naftel ◽  
Edward V. Colvin ◽  
...  
Keyword(s):  
Operative Procedure ◽  
Fontan Procedure ◽  
Fontan Operation ◽  
Pulmonary Arteries ◽  
Left Pulmonary Artery ◽  
Fontan Circulation ◽  
Caval Vein ◽  
Entire Cohort ◽  
Inferior Caval Vein ◽  
The Right

AbstractObjectiveIn 1990, Fontan, Kirklin, and colleagues published equations for survival after the so-called “Perfect Fontan” operation. After 1988, we evolved a protocol using an internal or external polytetraflouroethylene tube of 16 to 19 millimetres diameter placed from the inferior caval vein to either the right or left pulmonary artery along with a bidirectional cava-pulmonary connection. The objective of this study was to test the hypothesis that a “perfect” outcome is routinely achievable in the current era when using a standardized surgical procedure.MethodsBetween 1 January, 1988, and 12 December, 2005, 112 patients underwent the Fontan procedure using an internal or external polytetraflouroethylene tube plus a bidirectional cava-pulmonary connection, the latter usually having been constructed as a previous procedure. This constituted 45% of our overall experience in constructing the Fontan circulation between 1988 and 1996, and 96% of the experience between 1996 and 2005. Among all surviving patients, the median follow-up was 7.3 years. We calculated the expected survival for an optimal candidate, given from the initial equations, and compared this to our entire experience in constructing the Fontan circulation.ResultsAn internal tube was utilized in 61 patients, 97% of whom were operated prior to 1998, and an external tube in 51 patients, the latter accounting for 95% of all operations since 1999. At 1, 5, 10 and 15 years, survival of the entire cohort receiving polytetraflouroethylene tubes is superimposable on the curve calculated for a “perfect” outcome. Freedom from replacement or revision of the tube was 97% at 10 years.ConclusionUsing a standardized operative procedure, combining a bidirectional cavopulmonary connection with a polytetraflouroethylene tube placed from the inferior caval vein to the pulmonary arteries for nearly all patients with functionally univentricular hearts, early and late survival within the “perfect” outcome as predicted by the initial equations of Fontan and Kirklin is routinely achievable in the current era. The need for late revision or replacement of the tube is rare.

scholarly journals Mock Circulatory System of the Fontan Circulation to Study Respiration Effects on Venous Flow Behavior

ASAIO Journal ◽  
2013 ◽  
Vol 59 (3) ◽  
pp. 253-260 ◽  
Author(s):  
Marija Vukicevic ◽  
John A. Chiulli ◽  
Timothy Conover ◽  
Giancarlo Pennati ◽  
Tain Yen Hsia ◽  
...  
Keyword(s):  
Flow Behavior ◽  
Circulatory System ◽  
Fontan Circulation ◽  
Venous Flow ◽  
Mock Circulatory System

Late catheter interventions in hypoplastic left heart syndrome

2011 ◽  
Vol 21 (S2) ◽  
pp. 65-76 ◽  
Author(s):  
Jacqueline Kreutzer ◽  
Joseph N. Graziano ◽  
Gary Stapleton ◽  
Jonathan J. Rome
Keyword(s):  
Fontan Procedure ◽  
Pulmonary Arteries ◽  
Interventional Cardiology ◽  
Venous Hypertension ◽  
Hypoplastic Left Heart ◽  
Extracardiac Conduit ◽  
Younger Age ◽  
Arch Obstruction ◽  
Collateral Vessels ◽  
Left Heart Syndrome

AbstractInterventional cardiology plays a key role in the diagnosis and management of patients with functionally univentricular physiology after the various stages of surgical palliation. The interventions performed are widely variable in type, including angioplasty of stenotic vessels and implantation of stents in stenotic vessels; closure of defects such as collaterals, leaks in baffles, and fenestrations; creation of fenestration; and more. In the setting of venous hypertension associated with stenosis at the Fontan baffle, conduit, or pulmonary arteries, stent implantation is often preferred, as the aim is to eliminate completely the narrowing, given that relatively mild stenosis can have a significant detrimental hemodynamic effect in patients with functionally univentricular circulation. The procedure is highly successful. In patients who fail after Fontan procedure, creation of a fenestration is often performed, with variable technique depending on the underlying anatomic substrate. To increase chances of patency of the fenestration, implantation of a stent is often required, particularly in the setting of an extracardiac conduit. For those patients with cyanosis and favorable Fontan hemodynamics, closure of the fenestration is performed using atrial septal occluder devices with high success rate. Coils compatible with magnetic resonance imaging are used widely to treat collateral vessels, although on occasion other specific embolization tools are required, such as particles or vascular plugs. Postoperative arch obstruction is successfully managed with angioplasty at a younger age, while implantation of a stent in the aorta is reserved for older patients. Specifics of these interventional procedures as applied to the population of patients with functionally univentricular hearts are described in this manuscript.

scholarly journals Protein-Losing Enteropathy and Plastic Bronchitis After the Fontan Operation

2018 ◽  
Vol 38 (6) ◽  
pp. e5-e12 ◽  
Author(s):  
Christine Peyton
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Complex Disease ◽  
Fontan Procedure ◽  
Fontan Operation ◽  
Venous Pressure ◽  
Venous Hypertension ◽  
Plastic Bronchitis ◽  
Protein Losing Enteropathy ◽  
Fontan Physiology

Protein-losing enteropathy and plastic bronchitis remain challenging to treat despite recent treatment advances. Protein-losing enteropathy and plastic bronchitis have been diagnosed in patients with cardiomyopathy, constrictive pericarditis, and congestive heart failure. This article focuses on patients with protein-losing enteropathy or plastic bronchitis following the Fontan procedure. Patients with single-ventricle physiology who have undergone the Fontan procedure are at risk for these conditions. Fontan physiology predisposes patients to chronically low cardiac output, increased central venous pressure, and congestive heart failure. These altered hemodynamics lead to increased mesenteric vascular resistance, resulting in venous hypertension and congestion in protein-losing enteropathy. Plastic bronchitis is a complex disease in which chronic high lymphatic pressures from Fontan physiology cause acellular bronchial casts to develop. These entities may also occur in patients with normal Fontan hemodynamics. This article also covers medical and surgical interventions for protein-losing enteropathy and plastic bronchitis. (Critical Care Nurse. 2018;38[6]:e5–e12)

Characterization and treatment of systemic venous to pulmonary venous collaterals seen after the Fontan operation

2003 ◽  
Vol 13 (5) ◽  
pp. 424-430 ◽  
Author(s):  
Hisashi Sugiyama ◽  
Shi-Joon Yoo ◽  
William Williams ◽  
Lee N. Benson
Keyword(s):  
Fontan Operation ◽  
Fontan Circulation ◽  
Brachiocephalic Vein ◽  
Interventional Treatment ◽  
Mean Pulmonary Arterial Pressure ◽  
Venous Collaterals ◽  
Pulmonary Arterial ◽  
Transcatheter Interventions ◽  
Cardiac Catherization

Objectives: To determine the anatomical characteristics of systemic venous collaterals formed after the Fontan operation, and the efficacy of a transcatheter strategy for management. Methods: We reviewed retrospectively the data from cardiac catherization of 50 persistently cyanotic patients after the Fontan operation. Results: A total of 54 transcatheter interventions were performed, at a mean age of 6.3 ± 3.5 years, a mean interval of 2.7 ± 2.9 years from completion of the Fontan circulation. Of 38 patients who had fenestration of the baffle at the time of surgery, 25 had patency of the fenestration, and 24 had the fenestration occluded with a device at the time of interventional treatment for associated venous collaterals. We identified a total of 68 systemic venous collateral channels, of which 36 (53%) were supracardiac, 12 (18%) cardiac, and 20 (29%) infracardiac in origin. The most common site of origin was the brachiocephalic vein (44%), followed by the left phrenic vein (25%). A longer time from surgery, at 3.3 ± 3.4 years, was associated with the identification of collaterals having a diameter larger than 4 mm (p < 0.01). The mean pulmonary arterial pressure was higher in those with larger compared to those with smaller collaterals (13.3 ± 2.8 versus 11.1 ± 2.0 mmHg, p < 0.01). Coils were used for occlusion of 61 vessels, and a Rashkind™ occluder for the remaining 7. After exclusion of the patients undergoing simultaneous closure of their fenestration, systemic saturation of oxygen increased from 89 ± 6% to 95 ± 3% (p < 0.01). Conclusion: Venous collateral channels are common in patients suffering progressive cyanosis in the setting of the Fontan circulation. The collaterals increase in size with time, and are associated with higher pulmonary arterial pressures. Transcatheter treatment is feasible, and results in resolution of cyanosis. Only continuing follow-up will show whether further collateralization occurs in time.

scholarly journals REDUCED HEPATIC VENOUS FLOW IS A MARKER OF ADVERSE OUTCOMES IN PATIENTS WITH FONTAN CIRCULATION

2014 ◽  
Vol 63 (12) ◽  
pp. A566 ◽  
Author(s):  
Makoto Mori ◽  
Maan Jokhadar ◽  
Kayoko Shioda ◽  
Anurag Sahu ◽  
Robert Elder ◽  
...  
Keyword(s):  
Fontan Circulation ◽  
Adverse Outcomes ◽  
Venous Flow ◽  
Hepatic Venous Flow

Effects of Respiration and Gravity on Infradiaphragmatic Venous Flow in Normal and Fontan Patients

Circulation ◽  
2000 ◽  
Vol 102 (suppl_3) ◽  
Author(s):  
Tain-Yen Hsia ◽  
Sachin Khambadkone ◽  
Andrew N. Redington ◽  
Francesco Migliavacca ◽  
John E. Deanfield ◽  
...  
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Venous Return ◽  
Fontan Circulation ◽  
Flow Rate Ratio ◽  
Venous Flow ◽  
Beneficial Effects ◽  
In Series ◽  
Expiratory Flow ◽  
Fontan Patients

Background —In the Fontan circulation, pulmonary and systemic vascular resistances are in series. The implications of this unique arrangement on infradiaphragmatic venous physiology are poorly understood. Methods and Results —We studied the effects of respiration and gravity on infradiaphragmatic venous flows in 20 normal healthy volunteers (control) and 48 Fontan patients (atriopulmonary connection [APC] n=15, total cavopulmonary connection [TCPC] n=30). Hepatic venous (HV), subhepatic inferior vena caval (IVC), and portal venous (PV) flow rates were measured with Doppler ultrasonography during inspiration and expiration in both the supine and upright positions. The inspiratory-to-expiratory flow rate ratio was calculated to reflect the effect of respiration, and the supine-to-upright flow rate ratio was calculated to assess the effect of gravity. HV flow depended heavily on inspiration in TCPC compared with both control and APC subjects (inspiratory-to-expiratory flow rate ratio 3.4, 1.7, and 1.6, respectively; P <0.0001). Normal PV flow was higher in expiration, but this effect was lost in TCPC and APC patients (inspiratory-to-expiratory flow rate ratio 0.8, 1.0, and 1.1, respectively; P =0.01). The respiratory influence on IVC flow was the same in all groups. Gravity decreased HV flow more in APC than in TCPC patients (supine-to-upright flow rate ratio 3.2 versus 2.1, respectively; P <0.04) but reduced PV flow equally in all groups. Conclusions —Gravity and respiration have important influences on infradiaphragmatic venous return in Fontan patients. Although gravity exerts a significant detrimental effect on lower body venous return, which is more marked in APC than in TCPC patients, the beneficial effects of respiration in TCPC patients are mediated primarily by an increase in HV flow. These effects may have important short- and long-term implications for the hemodynamics of the Fontan circulation.

Current treatment options for the Failing Fontan Circulation

2022 ◽  
Vol 18 ◽  
Author(s):  
Bart. W. Driesen ◽  
Michiel Voskuil ◽  
Heynric B. Grotenhuis
Keyword(s):  
Myocardial Dysfunction ◽  
Fontan Procedure ◽  
Treatment Options ◽  
Fontan Operation ◽  
Current Treatment ◽  
Fontan Circulation ◽  
Protein Losing Enteropathy ◽  
Resistance Protein ◽  
Failing Fontan

Abstract: 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.

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