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.

Implementing the Sano Modification in an Experimental Model of the Norwood Circulation

2012 ◽  
Author(s):  
Giovanni Biglino ◽  
Alessandro Giardini ◽  
Catriona Baker ◽  
Tain-Yen Hsia ◽  
Richard S. Figliola ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Experimental Model ◽  
Circulatory System ◽  
Systemic Circulation ◽  
Norwood Procedure ◽  
Patient Specific ◽  
Surgical Approaches ◽  
Mock Circulatory System ◽  
Stage 1

Surgical palliation of hypoplastic left heart syndrome (HLHS) is performed in three stages, the first of which is known as the Norwood procedure [1]. Traditionally, this operation involves securing an unobstructed outlet for the systemic circulation in infants for whom the single right ventricle is the only pump in the system, with pulmonary flow sourced via a modified Blalock-Taussig (BT) shunt. In 2003, Sano et al. have proposed a radical variation of this operation, known as the Sano modification [2]. In this case, the pulmonary circulation is supplied directly from the systemic right ventricle via an unvalved ventriculo-pulmonary Goretex conduit, or Sano shunt. Characteristically, flow in the Sano shunt continues throughout diastole (diastolic runoff). Differences between surgical approaches for stage 1 palliation have been addressed in the literature [3]. A computational model of Norwood procedure and Sano modification has also been proposed [4]. However, an experimental model of this complex physiology is currently lacking. Having recently presented an in vitro model of stage 1 physiology with a BT shunt arrangement [5], we propose here a compact mock circulatory system suitable for simulating the Sano physiology in patient-specific anatomical models.

Use of a saphenous venous homograft for constructing a conduit from the right ventricle to the pulmonary arteries in the Norwood procedure

2004 ◽  
Vol 14 (3) ◽  
pp. 325-327 ◽  
Author(s):  
Luca A. Vricella ◽  
Jane E. Crosson ◽  
Duke E. Cameron
Keyword(s):  
Birth Weight ◽  
Right Ventricle ◽  
Pulmonary Arteries ◽  
Operative Management ◽  
Norwood Procedure ◽  
Left Heart ◽  
Hypoplastic Left Heart ◽  
Pulmonary Arterial ◽  
The Right ◽  
Left Heart Syndrome

The use of a conduit of polytetrafluoroethylene placed between the right ventricle and the pulmonary arteries as source of pulmonary arterial supply during the first stage of palliation for the hypoplastic left heart syndrome has facilitated post-operative management and resulted in decreased mortality. We describe here the use of a cryopreserved saphenous vein inserted in reversed direction to create the connection between the right ventricle and the pulmonary arteries in a neonate with low birth weight undergoing the modified Norwood procedure.

scholarly journals Geometry of the pulmonary arteries before the Fontan operation: can we influence it during the Norwood procedure?

2020 ◽  
Vol 57 (6) ◽  
pp. 1098-1104
Author(s):  
Katarzyna Januszewska ◽  
Pawel Nawrocki ◽  
Anja Lehner ◽  
Julia Stegger ◽  
Felix Kleinerueschkamp ◽  
...  
Keyword(s):  
Hypoplastic Left Heart Syndrome ◽  
Fontan Operation ◽  
Pulmonary Arteries ◽  
Norwood Procedure ◽  
Left Heart ◽  
Hypoplastic Left Heart ◽  
Second Stage ◽  
The Right ◽  
Left Heart Syndrome ◽  
The Impact

Abstract OBJECTIVES The right ventricle-to-pulmonary artery (RV-PA) shunt provides stable haemodynamics after the Norwood procedure but can influence development of the central pulmonary arteries (PAs). The goal of this study was to analyse the geometry of the central PAs in children with hypoplastic left heart syndrome before the Fontan operation with respect to the RV-PA shunt site and the type of the second-stage operation. METHODS A total of 161 children with hypoplastic left heart syndrome, median age 2.7 (range 1.3–9.8) years and median weight 12.7 (range 7.6–26.1) kg, underwent the Fontan operation after having had the Norwood procedure with an RV-PA shunt. The patients were divided into 2 groups: left-sided RV-PA (L-RV-PA) (n = 129) with the shunt on the left and right-sided RV-PA (n = 32) with the shunt on the right side of the neoaorta. Angiographic data obtained before the Fontan and all cardiac catheterization interventions were analysed retrospectively. RESULTS Between the second and third stages, as well as directly before the Fontan operation, the L-RV-PA group required more PA catheter interventions (P = 0.001 and P = 0.03). In this group, the minimal left PA diameter was smaller than that in the R-RV-PA group (P = 0.021). Leaving the shunt open until the Fontan operation increased the rate of PA interventions in the L-RV-PA group (P = 0.001), but there is no evidence of the impact on the development of the left PAs (P = 0.075). There is also no evidence that the type of the second-stage procedure influences the intervention rate before the Fontan procedure (P = 0.14). CONCLUSIONS Children who have the L-RV-PA shunt require more PA catheter interventions. The right-sided RV-PA shunt and the subsequent Glenn anastomosis in the place of the shunt are associated with distortion-free and more symmetrical development of the central PAs.

Successful use of oral prostaglandin E1 derivative for maintaining ductus-dependent systemic circulation in a neonate with trisomy 18

2019 ◽  
Vol 29 (09) ◽  
pp. 1222-1224
Author(s):  
Akiko Miyake ◽  
Seigo Okada ◽  
Yuichi Ishikawa
Keyword(s):  
Prostaglandin E1 ◽  
Treatment Approach ◽  
Ductus Arteriosus ◽  
Feeding Tube ◽  
Systemic Circulation ◽  
Trisomy 18 ◽  
Hypoplastic Left Heart ◽  
Japanese Female ◽  
Alternative Drug ◽  
Left Heart Syndrome

AbstractA Japanese female infant with trisomy 18 was diagnosed with hypoplastic left heart syndrome variant. She was administered oral prostaglandin E1 every 6 hours through a feeding tube as an alternative drug for lipo-prostaglandin E1. Oral prostaglandin E1 was effective for maintenance of the ductus arteriosus and may serve as a palliative treatment approach.

scholarly journals Noninvasive Imaging in Interventional Cardiology: Hypoplastic Left Heart Syndrome

2021 ◽  
Vol 8 ◽  
Author(s):  
Hannah Bellsham-Revell
Keyword(s):  
Hypoplastic Left Heart Syndrome ◽  
Pulmonary Arteries ◽  
Interventional Cardiology ◽  
Systemic Circulation ◽  
Fontan Circulation ◽  
Active Management ◽  
Left Heart ◽  
Hypoplastic Left Heart ◽  
Systemic Right Ventricle ◽  
Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a spectrum of left heart underdevelopment leaving the left side unable to support the systemic circulation. If active management is pursued, then the condition is managed with staged palliation to the Fontan circulation, leaving a systemic right ventricle. Through all surgical stages, and even after completion of Fontan, there are multiple areas that may require intervention, most frequently the branch pulmonary arteries which are essential to a successful Fontan circulation. Echocardiography is the mainstay of assessment, but there is an increasing use of magnetic resonance imaging (MRI) and computed tomography (CT) particularly in relation to extracardiac structures which can be more challenging with echocardiography. Both MRI and CT require set-up, experience and training, and usually sedation or anesthetic in smaller children, but can provide excellent imaging to guide interventions. Cardiac MRI is also able to quantify right ventricular (RV) function which can be challenging on echocardiography. This article describes the modalities available and their use in assessing patients with HLHS prior to catheter interventions.

scholarly journals Characterization of Post-Operative Hemodynamics Following the Norwood Procedure Using Population Data and Multi-Scale Modeling

2021 ◽  
Vol 12 ◽  
Author(s):  
Jonathan Primeaux ◽  
Arash Salavitabar ◽  
Jimmy C. Lu ◽  
Ronald G. Grifka ◽  
C. Alberto Figueroa
Keyword(s):  
High Frequency ◽  
Pulmonary Arteries ◽  
Somatic Growth ◽  
Population Data ◽  
Population Based ◽  
Stage I ◽  
Stage Ii ◽  
Morphological Data ◽  
Norwood Procedure ◽  
Patient Specific

Children with hypoplastic left heart syndrome (HLHS) must undergo multiple surgical stages to reconstruct the anatomy to a sustainable single ventricle system. Stage I palliation, or the Norwood procedure, provides circulation to both pulmonary and systemic vasculature. The aorta is reconstructed and attached to the right ventricle and a fraction of systemic flow is redirected to the pulmonary arteries (PAs) through a systemic-to-PA shunt. Despite abundant hemodynamic data available 4–5 months after Norwood palliation, data is very scarce immediately following stage I. This data is critical in determining post-operative success. In this work, we combined population data and computational fluid dynamics (CFD) to characterize hemodynamics immediately following stage I (post-stage I) and prior to stage II palliation (pre-stage II). A patient-specific model was constructed as a baseline geometry, which was then scaled to reflect population-based morphological data at both time-points. Population-based hemodynamic data was then used to calibrate each model to reproduce blood flow representative of HLHS patients. The post-stage I simulation produced a PA pressure of 22 mmHg and high-frequency oscillations within the flow field indicating highly disturbed hemodynamics. Despite PA mean pressure dropping to 14 mmHg, the pre-stage II model also produced high-frequency flow components and PA wall shear stress increases. These suboptimal conditions may be necessary to ensure adequate PA flow throughout the pre-stage II period, as the shunt becomes relatively smaller compared to the patient’s somatic growth. In the future, CFD can be used to optimize shunt design and minimize these suboptimal conditions.

scholarly journals Early outcomes and computational fluid dynamic analyses of chimney reconstruction in the Norwood procedure

2019 ◽  
Vol 29 (2) ◽  
pp. 252-259 ◽  
Author(s):  
Satoshi Asada ◽  
Masaaki Yamagishi ◽  
Keiichi Itatani ◽  
Yoshinobu Maeda ◽  
Satoshi Taniguchi ◽  
...  
Keyword(s):  
Aortic Arch ◽  
Hypoplastic Left Heart Syndrome ◽  
Fluid Dynamic ◽  
Norwood Procedure ◽  
Patient Specific ◽  
Shear Stresses ◽  
Left Heart ◽  
Hypoplastic Left Heart ◽  
Flow Profiles ◽  
Left Heart Syndrome

Abstract OBJECTIVES The ideal configuration of a reconstructed aortic arch in the Norwood procedure for hypoplastic left heart syndrome is still a matter of debate. Chimney reconstruction was developed to avoid postoperative complications and turbulent flow in the aortic arch. This study sought to clarify early outcomes of the procedure and verify its haemodynamic advantages using computational fluid dynamics (CFD). METHODS Fourteen consecutive patients with hypoplastic left heart syndrome or a variant who underwent chimney reconstruction in the Norwood procedure between January 2013 and March 2018 were enrolled. Median age and body weight at the time of operation were 2.5 months and 4.1 kg, respectively. Thirteen patients (93.9%) had been palliated with previous bilateral pulmonary artery (PA) banding. In addition, patient-specific CFD models of neoarches based on postoperative computed tomograms from 6 patients were created and the flow profiles analysed. RESULTS Survival rates at 1, 3 and 5 years were 76.6%, 67.3% and 67.3%, respectively. No patient developed left PA compression by neoaorta, neoaortic dilation or neoaortic insufficiency. Only 2 patients (14.3%) required surgical intervention for recoarctation. Fontan completion was performed on 5 patients. On CFD analysis, all reconstructed aortic arches showed low energy loss (9.16–14.4 mW/m2) and low wall shear stresses. CONCLUSIONS Chimney reconstruction was a feasible technique when homografts were not readily available. CFD analyses underscored the fact that this technique produced excellent flow profiles. Larger studies should be conducted to clarify long-term outcomes.

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.

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.

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