Invasive Lobular Carcinoma-Correlation Between Imaging and Final Pathology: Is MRI Better?

BACKGROUND: Invasive lobular carcinoma (ILC) is associated with high re-excision rates following breast-conserving surgery (BCS). The correlation between lesion size on different imaging modalities and final tumor size has not been well characterized. METHODS: A prospective database of patients with stage I-III breast cancer undergoing BCS between 2006 and 2016 was reviewed. Pearson correlation analysis was used to correlate tumor size on breast imaging to final pathology. RESULTS: Of these, 111 patients with ILC were identified. Mean lesion size was 1.93 cm for MMG, 1.61 cm for US, and 2.51 cm for MRI. Mean tumor size on surgical excision was 2.64 cm. The correlation coefficient between pathology and the different imaging modalities were as follows: MMG .17, US 0.37, and MRI .58. Actual tumor size was underestimated by 1 cm in 27.1% of MMGs, 50% of USs, and in 13.3% of MRIs. 38 patients (34.2%) underwent re-excision. No differences in re-excision rates were noted in patients with and without MRI, 30.3% vs 40.0%, respectively (P = .31). CONCLUSION: While MRI provides a better estimate of tumor size than MMG and US, the size of the tumor on imaging only weakly correlated with pathology. The use of MRI does not decrease re-excision rates.

Management of SIADH-related hyponatremia due to psychotropic medications - An expert consensus from the Association of Medicine and Psychiatry.

OBJECTIVE: Hyponatremia is the most common electrolyte imbalance encountered in clinical practice and is associated with negative healthcare outcomes and cost. SIADH is thought to account for one third of all hyponatremia cases and is typically an insidious process. Psychotropic medications are commonly implicated in the etiology of drug induced SIADH. There is limited guidance for clinicians on management of psychotropic-induced SIADH. METHODS: After an extensive review of the existing literature, clinical-educators from the Association of Medicine and Psychiatry developed expert consensus recommendations for management of psychotropic-induced SIADH. A risk score was proposed based on risk factors for SIADH to guide clinical decision-making. RESULTS: SSRIs, SNRIs, antipsychotics, carbamazepine, and oxcarbazepine have moderate to high level of evidence demonstrating their association with SIADH. Evaluation for an avoidance of medications that cause hyponatremia is particularly important. Substitution with medication that is less likely to cause SIADH should be considered when appropriate. We propose an algorithmic approach to monitoring hyponatremia with SIADH and corresponding treatment depending on symptom severity. CONCLUSIONS: The proposed algorithm can help clinicians in determining whether psychotropic medication should be stopped, reduced or substituted where SIADH is suspected with recommendations for sodium (Na+) monitoring. These recommendations preserve a role for clinical judgment in the management of hyponatremia with consideration of the risks and benefits, which may be particularly relevant for complex patients that present with medical and psychiatric comorbidities. Further studies are needed to determine whether baseline and serial Na+ monitoring reduces morbidity and mortality.

Functional deficits and other psychiatric associations with abnormal scores on the Montreal Cognitive Assessment (MoCA) in older HIV-infected patients.

OBJECTIVE: The authors assessed the association of physical function, social variables, functional status, and psychiatric co-morbidity with cognitive function among older HIV-infected adults. DESIGN: From 2012-2014, a cross-sectional study was conducted among HIV-infected patients ages 50 or older who underwent comprehensive clinical geriatric assessment. SETTING: Two San Francisco HIV clinics. PARTICIPANTS: 359 HIV-infected patients age 50 years or older. MEASUREMENTS: Unadjusted and adjusted Poisson regression measured prevalence ratios and 95% confidence intervals for demographic, functional and psychiatric variables and their association with cognitive impairment using a Montreal Cognitive Assessment (MoCA) score < 26 as reflective of cognitive impairment. RESULTS: Thirty-four percent of participants had a MoCA score of < 26. In unadjusted analyses, the following variables were significantly associated with an abnormal MoCA score: born female, not identifying as homosexual, non-white race, high school or less educational attainment, annual income < $10,000, tobacco use, slower gait speed, reported problems with balance, and poor social support. In subsequent adjusted analysis, the following variables were significantly associated with an abnormal MoCA score: not identifying as homosexual, non-white race, longer 4-meter walk time, and poor social support. Psychiatric symptoms of depressive, anxiety, and post-traumatic stress disorders did not correlate with abnormal MoCA scores. CONCLUSIONS: Cognitive impairment remains common in older HIV-infected patients. Counter to expectations, co-morbid psychiatric symptoms were not associated with cognitive impairment, suggesting that cognitive impairment in this sample may be due to neurocognitive disorders, not due to other psychiatric illness. The other conditions associated with cognitive impairment in this sample may warrant separate clinical and social interventions to optimize patient outcomes.

Multiblock High Order Large Eddy Simulation of Powered Fontan Hemodynamics: Towards Computational Surgery.

Children born with only one functional ventricle must typically undergo a series of three surgeries to obtain the so-called Fontan circulation in which the blood coming from the body passively flows from the Vena Cavae (VCs) to the Pulmonary Arteries (PAs) through the Total Cavopulmonary Connection (TCPC). The circulation is inherently inefficient due to the lack of a subpulmonary ventricle. Survivors face the risk of circulatory sequelae and eventual failure for the duration of their lives. Current efforts are focused on improving the outcomes of Fontan palliation, either passively by optimizing the TCPC, or actively by using mechanical support. We are working on a chronic implant that would be placed at the junction of the TCPC, and would provide the necessary pressure augmentation to re-establish a circulation that recapitulates a normal two-ventricle circulation. This implant is based on the Von Karman viscous pump and consists of a vaned impeller that rotates inside the TCPC. To evaluate the performance of such a device, and to study the flow features induced by the presence of the pump, Computational Fluid Dynamics (CFD) is used. CFD has become an important tool to understand hemodynamics owing to the possibility of simulating quickly a large number of designs and flow conditions without any harm for patients. The transitional and unsteady nature of the flow can make accurate simulations challenging. We developed and in-house high order Large Eddy Simulation (LES) solver coupled to a recent Immersed Boundary Method (IBM) to handle complex geometries. Multiblock capability is added to the solver to allow for efficient simulations of complex patient specific geometries. Blood simulations are performed in a complex patient specific TCPC geometry. In this study, simulations without mechanical assist are performed, as well as after virtual implantation of the temporary and chronic implants being developed. Instantaneous flow structures, hepatic factor distribution, and statistical data are presented for all three cases.

Dynamic Mode Decomposition of Fontan Hemodynamics in an Idealized Total Cavopulmonary Connection.

Univentricular heart disease is the leading cause of death from any birth defect in the first year of life. Typically, patients have to undergo three open heart surgical procedures within the first few years of their lives to eventually directly connect the superior and inferior vena cavae to the left and right pulmonary arteries forming the Total Cavopulmonary Connection or TCPC. The end result is a weak circulation where the single working ventricle pumps oxygenated blood to the body and de-oxygenated blood flows passively through the TCPC into the lungs. The fluid dynamics of the TCPC junction involve confined impinging jets resulting in a highly unstable flow, significant mechanical energy dissipation, and undesirable pressure loss. Understanding and predicting such flows is important for improving the surgical procedure and for the design of mechanical cavopulmonary assist devices. In this study, Dynamic Mode Decomposition (DMD) is used to analyze previously obtained Stereoscopic Particle Imaging Velocimetry (SPIV) data and Large Eddy Simulation (LES) results for an idealized TCPC. Analysis of the DMD modes from the SPIV and LES serve to both highlight the unsteady vortical dynamics and the qualitative agreement between measurements and simulations.

Cavopulmonary assist for the failing Fontan circulation: impact of ventricular function on mechanical support strategy.

Mechanical circulatory support--either ventricular assist device (VAD, left-sided systemic support) or cavopulmonary assist device (CPAD, right-sided support)--has been suggested as treatment for Fontan failure. The selection of left- versus right-sided support for failing Fontan has not been previously defined. Computer simulation and mock circulation models of pediatric Fontan patients (15-25 kg) with diastolic, systolic, and combined systolic and diastolic dysfunction were developed. The global circulatory response to assisted Fontan flow using VAD (HeartWare HVAD, Miami Lakes, FL) support, CPAD (Viscous Impeller Pump, Indianapolis, IN) support, and combined VAD and CPAD support was evaluated. Cavopulmonary assist improves failing Fontan circulation during diastolic dysfunction but preserved systolic function. In the presence of systolic dysfunction and elevated ventricular end-diastolic pressure (VEDP), VAD support augments cardiac output and diminishes VEDP, while increased preload with cavopulmonary assist may worsen circulatory status. Fontan circulation can be stabilized to biventricular values with modest cavopulmonary assist during diastolic dysfunction. Systemic VAD support may be preferable to maintain systemic output during systolic dysfunction. Both systemic and cavopulmonary support may provide best outcome during combined systolic and diastolic dysfunction. These findings may be useful to guide clinical cavopulmonary assist strategies in failing Fontan circulations.

Large eddy simulation of transitional flow in an idealized stenotic blood vessel: evaluation of subgrid scale models.

In the present study, we performed large eddy simulation (LES) of axisymmetric, and 75% stenosed, eccentric arterial models with steady inflow conditions at a Reynolds number of 1000. The results obtained are compared with the direct numerical simulation (DNS) data (Varghese et al., 2007, "Direct Numerical Simulation of Stenotic Flows. Part 1. Steady Flow," J. Fluid Mech., 582, pp. 253-280). An inhouse code (WenoHemo) employing high-order numerical methods for spatial and temporal terms, along with a 2nd order accurate ghost point immersed boundary method (IBM) (Mark, and Vanwachem, 2008, "Derivation and Validation of a Novel Implicit Second-Order Accurate Immersed Boundary Method," J. Comput. Phys., 227(13), pp. 6660-6680) for enforcing boundary conditions on curved geometries is used for simulations. Three subgrid scale (SGS) models, namely, the classical Smagorinsky model (Smagorinsky, 1963, "General Circulation Experiments With the Primitive Equations," Mon. Weather Rev., 91(10), pp. 99-164), recently developed Vreman model (Vreman, 2004, "An Eddy-Viscosity Subgrid-Scale Model for Turbulent Shear Flow: Algebraic Theory and Applications," Phys. Fluids, 16(10), pp. 3670-3681), and the Sigma model (Nicoud et al., 2011, "Using Singular Values to Build a Subgrid-Scale Model for Large Eddy Simulations," Phys. Fluids, 23(8), 085106) are evaluated in the present study. Evaluation of SGS models suggests that the classical constant coefficient Smagorinsky model gives best agreement with the DNS data, whereas the Vreman and Sigma models predict an early transition to turbulence in the poststenotic region. Supplementary simulations are performed using Open source field operation and manipulation (OpenFOAM) ("OpenFOAM," http://www.openfoam.org/) solver and the results are inline with those obtained with WenoHemo.

The medical-psychiatric coordinating physician-led model: team-based treatment for complex patients.

OBJECTIVE: We propose a patient care model involving psychiatrist-led multispecialty teams for treatment of the most treatment-refractory segment of "complex" outpatients. We call the psychiatrist taking this leadership role the Medical-Psychiatric Coordinating Physician. METHOD: The authors conducted a pilot study for this treatment model with 52 office-based outpatient cases each involving complex patients, and each with at least 2 major treatment failures. They followed these patients empirically for at least 18 months. Outcomes examined included Hamilton Anxiety Rating Scale; Hamilton Depression Rating Scale; and Health Related Quality of Life-14 scores (HRQOL-14, modified), in association with a comprehensive treatment review. RESULTS: Comprehensive treatment review indicated sustained improvement in at least 2 of 4 clinical dimensions (utilization, treatment adherence, symptomatology, and quality of life) in 44 of 52 patients. Included were Hamilton Anxiety Rating Scale scores that improved significantly from 26.27 ± 7.5 to 18.13 ± 5.74 (p < 0.0001) and Hamilton Depression Rating Scale scores that improved from 22.02 ± 7.10 to 14.58 ± 6.46 (p < 0.0001). The Health-Related Quality of Life-14 improved significantly for general health from 2.54 ± 1.03 to 2.12 ± 1.06 (p < 0.0001), and sick days per month from 11.22 ± 7.76 to 6.60 ± 7.51 (p < 0.0001). CONCLUSIONS: The Medical-Psychiatric Coordinating Physician-led multispecialty team method may be advantageous for the ongoing outpatient treatment of management-intensive, complex patients. We offer this model as having a place among the available integrated care models for the treatment of comorbid psychiatric-systemic medical illness.

Characterization of oscillatory instability in lid driven cavity flows using lattice Boltzmann method.

In the present work, lattice Boltzmann method (LBM) is applied for simulating flow in a three-dimensional lid driven cubic and deep cavities. The developed code is first validated by simulating flow in a cubic lid driven cavity at 1000 and 12000 Reynolds numbers following which we study the effect of cavity depth on the steady-oscillatory transition Reynolds number in cavities with depth aspect ratio equal to 1, 2 and 3. Turbulence modeling is performed through large eddy simulation (LES) using the classical Smagorinsky sub-grid scale model to arrive at an optimum mesh size for all the simulations. The simulation results indicate that the first Hopf bifurcation Reynolds number correlates negatively with the cavity depth which is consistent with the observations from two-dimensional deep cavity flow data available in the literature. Cubic cavity displays a steady flow field up to a Reynolds number of 2100, a delayed anti-symmetry breaking oscillatory field at a Reynolds number of 2300, which further gets restored to a symmetry preserving oscillatory flow field at 2350. Deep cavities on the other hand only attain an anti-symmetry breaking flow field from a steady flow field upon increase of the Reynolds number in the range explored. As the present work involved performing a set of time-dependent calculations for several Reynolds numbers and cavity depths, the parallel performance of the code is evaluated a priori by running the code on up to 4096 cores. The computational time required for these runs shows a close to linear speed up over a wide range of processor counts depending on the problem size, which establishes the feasibility of performing a thorough search process such as the one presently undertaken.

Assessment of stretched vortex subgrid-scale models for LES of incompressible inhomogeneous turbulent flow.

The physical space version of the stretched vortex subgrid scale model [Phys. Fluids 12, 1810 (2000)] is tested in large eddy simulations (LES) of the turbulent lid driven cubic cavity flow. LES is carried out using a higher order finite-difference method [J. Comput. Phys. 229, 8802 (2010)]. The effects of different vortex orientation models and subgrid turbulence spectrums are assessed through comparisons of the LES predictions against direct numerical simulations (DNS) [Phys. Fluids 12, 1363 (2000)]. Three Reynolds numbers 12000, 18000, and 22000 are studied. Good agreement with the DNS data for the mean and fluctuating quantities is observed.

Large Eddy Simulation of FDA's Idealized Medical Device.

A hybrid large eddy simulation (LES) and immersed boundary method (IBM) computational approach is used to make quantitative predictions of flow field statistics within the Food and Drug Administration's (FDA) idealized medical device. An in-house code is used, hereafter (W enoHemo™ ), that combines high-order finite-difference schemes on structured staggered Cartesian grids with an IBM to facilitate flow over or through complex stationary or rotating geometries and employs a subgrid-scale (SGS) turbulence model that more naturally handles transitional flows [2]. Predictions of velocity and wall shear stress statistics are compared with previously published experimental measurements from Hariharan et al. [6] for the four Reynolds numbers considered.

A novel multiblock immersed boundary method for large eddy simulation of complex arterial hemodynamics.

Computational fluid dynamics (CFD) simulations are becoming a reliable tool to understand hemodynamics, disease progression in pathological blood vessels and to predict medical device performance. Immersed boundary method (IBM) emerged as an attractive methodology because of its ability to efficiently handle complex moving and rotating geometries on structured grids. However, its application to study blood flow in complex, branching, patient-specific anatomies is scarce. This is because of the dominance of grid nodes in the exterior of the fluid domain over the useful grid nodes in the interior, rendering an inevitable memory and computational overhead. In order to alleviate this problem, we propose a novel multiblock based IBM that preserves the simplicity and effectiveness of the IBM on structured Cartesian meshes and enables handling of complex, anatomical geometries at a reduced memory overhead by minimizing the grid nodes in the exterior of the fluid domain. As pathological and medical device hemodynamics often involve complex, unsteady transitional or turbulent flow fields, a scale resolving turbulence model such as large eddy simulation (LES) is used in the present work. The proposed solver (here after referred as WenoHemo), is developed by enhancing an existing in-house high order incompressible flow solver that was previously validated for its numerics and several LES models by Shetty et al. [Journal of Computational Physics 2010; 229 (23), 8802-8822]. In the present work, WenoHemo is systematically validated for additional numerics introduced, such as IBM and the multiblock approach, by simulating laminar flow over a sphere and laminar flow over a backward facing step respectively. Then, we validate the entire solver methodology by simulating laminar and transitional flow in abdominal aortic aneurysm (AAA). Finally, we perform blood flow simulations in the challenging clinically relevant thoracic aortic aneurysm (TAA), to gain insights into the type of fluid flow patterns that exist in pathological blood vessels. Results obtained from the TAA simulations reveal complex vortical and unsteady flow fields that need to be considered in designing and implanting medical devices such as stent grafts.

Performance evaluation of a pediatric viscous impeller pump for Fontan cavopulmonary assist.

OBJECTIVE: The anatomic and physiologic constraints for pediatric cavopulmonary assist differ markedly from adult Fontan circulations owing to smaller vessel sizes and risk of elevated pulmonary resistance. In this study, hemodynamic and hemolysis performance of a catheter-based viscous impeller pump (VIP) to power the Fontan circulation is assessed at a pediatric scale (∼15 kg) and performance range (0-30 mm Hg). METHODS: Computer simulation and mock circulation studies were conducted to assess the hydraulic performance, acute hemodynamic response to different levels VIP support, and the potential for vena caval collapse. Computational fluid dynamics simulations were used to estimate VIP hydraulic performance, shear rates, and potential for hemolysis. Hemolysis was quantified in a mock loop with fresh bovine blood. RESULTS: A VIP augmented 4-way total cavopulmonary connection flow at pediatric scales and restored systemic pressures and flows to biventricular values, without causing flow obstruction or suction. VIP generated flows up to 4.1 L/min and pressure heads of up to 38 mm Hg at 11,000 rpm. Maximal shear rate was 160 Pa, predicting low hemolysis risk. Observed hemolysis was low with plasma free hemoglobin of 11.4 mg · dL(-1) · h(-1). CONCLUSIONS: A VIP will augment Fontan cavopulmonary flow in the proper pressure and flow ranges, with low hemolysis risk under more stringent pediatric scale and physiology compared with adult scale. This technology may be developed to simultaneously reduce systemic venous pressure and improve cardiac output after stage 2 or 3 Fontan repair. It may serve to compress surgical staging, lessening the pathophysiologic burden of repair.

Cavopulmonary assist: (em)powering the univentricular fontan circulation.

Since the Fontan/Kreutzer procedure was introduced, evolutionary clinical advances via a staged surgical reconstructive approach have markedly improved outcomes for patients with functional single ventricle. However, significant challenges remain. Early stage mortality risk seems impenetrable. Serious morbidities - construed as immutable consequences of palliation - have hardly been addressed. Late functional status is increasingly linked to pathophysiologic consequences of prior staged procedures. As more single-ventricle patients survive into adulthood, Fontan failure is emerging as an intractable problem for which there is no targeted therapy. Incremental solutions to address these ongoing problems have not had a measurable impact. Therefore, a fundamental reconsideration of the overall approach is reasonable and warranted. The ability to provide a modest pressure boost (2 to 6 mmHg) to existing blood flow at the total cavopulmonary connection can effectively restore more stable biventricular status. This would impact not only treatment of late Fontan failure, but also facilitate early surgical repair. A realistic means to provide such a pressure boost has never been apparent. Recent advances are beginning to unravel the unique challenges that must be addressed to realize this goal, with promise to open single-ventricle palliation to new therapeutic vistas.

Cavopulmonary assist for the univentricular Fontan circulation: von Kármán viscous impeller pump.

OBJECTIVE: In a univentricular Fontan circulation, modest augmentation of existing cavopulmonary pressure head (2-5 mm Hg) would reduce systemic venous pressure, increase ventricular filling, and thus substantially improve circulatory status. An ideal means of providing mechanical cavopulmonary support does not exist. We hypothesized that a viscous impeller pump, based on the von Kármán viscous pump principle, is optimal for this role. METHODS: A 3-dimensional computational model of the total cavopulmonary connection was created. The impeller was represented as a smooth 2-sided conical actuator disk with rotation in the vena caval axis. Flow was modeled under 3 conditions: (1) passive flow with no disc; (2) passive flow with a nonrotating disk, and (3) induced flow with disc rotation (0-5K rpm). Flow patterns and hydraulic performance were examined for each case. Hydraulic performance for a vaned impeller was assessed by measuring pressure increase and induced flow over 0 to 7K rpm in a laboratory mock loop. RESULTS: A nonrotating actuator disc stabilized cavopulmonary flow, reducing power loss by 88%. Disk rotation (from baseline dynamic flow of 4.4 L/min) resulted in a pressure increase of 0.03 mm Hg. A further increase in pressure of 5 to 20 mm Hg and 0 to 5 L/min flow was obtained with a vaned impeller at 0 to 7K rpm in a laboratory mock loop. CONCLUSIONS: A single viscous impeller pump stabilizes and augments cavopulmonary flow in 4 directions, in the desired pressure range, without venous pathway obstruction. A viscous impeller pump applies to the existing staged protocol as a temporary bridge-to-recovery or -transplant in established univentricular Fontan circulations and may enable compressed palliation of single ventricle without the need for intermediary surgical staging or use of a systemic-to-pulmonary arterial shunt.

Performance of a 3-bladed propeller pump to provide cavopulmonary assist in the failing Fontan circulation.

PURPOSE: We hypothesized that a propeller pump design would function optimally to provide cavopulmonary assist in a univentricular Fontan circulation. DESCRIPTION: The hydraulic and hemolysis performance of a rigid three-bladed propeller prototype (similar to a folding propeller design) was characterized. Pressure and flow measurements were taken for flow rates of 0.5 to 3 liters per minute (LPM) for 5,000 to 7,000 revolutions per minute (RPM) using a blood analog fluid. Hemolysis testing was performed using fresh bovine blood for 2 LPM at 6,000 RPM for a 6-hour duration. EVALUATION: The prototype performed well over the design operating range by producing a pressure rise of 5 to 50 mm Hg. Plasma free hemoglobin concentration remained less than 15 mg/dL. The normalized index of hemolysis peaked during the first hour, and then remained less than 10 mg/dL thereafter. CONCLUSIONS: A propeller pump has the pressure-flow characteristics and minimal risk of hemolysis and venous pathway obstruction which make it ideal for temporary cavopulmonary assist. This type of device has the potential to provide a new therapeutic option for patients with failing univentricular Fontan physiology as a bridge-to-recovery or transplantation.

Comparing turbulence models for flow through a rigid glottal model.

Flow through a rigid model of the human vocal tract featuring a divergent glottis was numerically modeled using the Reynolds-averaged Navier-Stokes approach. A number of different turbulence models, available in a widely used commercial computational fluid dynamics code, were tested to determine their ability to capture various flow features recently observed in laboratory experiments and large eddy simulation studies. The study reveals that results from unsteady simulations employing the k-omega shear stress transport model were in much better agreement with previous measurements and predictions with regard to the ability to predict glottal jet skewing due to the Coanda effect and the intraglottal pressure distribution or related skin friction coefficient, than either steady or unsteady simulations using the Spalart-Allmaras model or any other two-equation turbulence model investigated in this study.

Modeling transition to turbulence in eccentric stenotic flows.

Mean flow predictions obtained from a host of turbulence models were found to be in poor agreement with recent direct numerical simulation results for turbulent flow distal to an idealized eccentric stenosis. Many of the widely used turbulence models, including a large eddy simulation model, were unable to accurately capture the poststenotic transition to turbulence. The results suggest that efforts toward developing more accurate turbulence models for low-Reynolds number, separated transitional flows are necessary before such models can be used confidently under hemodynamic conditions where turbulence may develop.

Mechanical cavopulmonary assist for the univentricular Fontan circulation using a novel folding propeller blood pump.

A blood pump specifically designed to operate in the unique anatomic and physiologic conditions of a cavopulmonary connection has never been developed. Mechanical augmentation of cavopulmonary blood flow in a univentricular circulation would reduce systemic venous pressure, increase preload to the single ventricle, and temporarily reproduce a scenario analogous to the normal two-ventricle circulation. We hypothesize that a folding propeller blood pump would function optimally in this cavopulmonary circulation. The hydraulic performance of a two-bladed propeller prototype was characterized in an experimental flow loop using a blood analog fluid for 0.5-3.5 lpm at rotational speeds of 3,600-4,000 rpm. We also created five distinctive blood pump designs and evaluated their hydraulic performance using computational fluid dynamics (CFD). The two-bladed prototype performed well over the design range of 0.5-3.5 lpm, producing physiologic pressure rises of 5-18 mm Hg. Building upon this proof-of-concept testing, the CFD analysis of the five numerical models predicted a physiologic pressure range of 5-40 mm Hg over 0.5-4 lpm for rotational speeds of 3,000-7,000 rpm. These preliminary propeller designs and the two-bladed prototype achieved the expected hydraulic performance. Optimization of these configurations will reduce fluid stress levels, remove regions of recirculation, and improve the hydraulic performance of the folding propeller. This propeller design produces the physiologic pressures and flows that are in the ideal range to mechanically support the cavopulmonary circulation and represents an exciting new therapeutic option for the support of a univentricular Fontan circulation.