Virtual Transcatheter Interventions for Peripheral Pulmonary Artery Stenosis in Williams and Alagille Syndromes

Figures

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  Figure 1. Automated tuning of preinterventional boundary conditions. A, The main pulmonary artery (MPA) inlet is coupled to a right heart network consisting of a constant right atrial (RA) pressure (PRA), tricuspid valve (TV), right ventricle (RV), and pulmonary valve (PV). Each outlet is coupled to 3 RCR Windkessel models in series, corresponding to the arterial, capillary, and venous compartments, with a constant left atrial (LA) pressure (PLA). B, For tuning of patient‐specific boundary conditions (BCs), the PA model is reduced to a 0‐dimensional surrogate, and the outlet BCs are bilaterally aggregated. LPA indicates left pulmonary artery; PA, pulmonary artery; RPA, right pulmonary artery; PLPA, LPA pressure, PMPA, MPA pressure; and PRPA, RPA pressure. All C’s indicate capacitances, k’s indicate coefficients for Bernoulli‐type resistors, and R’s indicate resistances. Subscripts 1 and 2 indicate aggregated parameters for the right and left trees, respectively. Subscripts a, c, and v indicate arterial, capillary, and venous parameters. Subscripts p and d indicate proximal and distal parameters.

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  Figure 2. Virtual proximal and extensive transcatheter interventions. Catheterization angiograms indicating representative lesions, the image‐based preinterventional models, and modified segmentations for virtual repair. Stent diameters are annotated. AS indicates Alagille syndrome; Extv, extensive intervention; Pre, preintervention; Prox, proximal intervention; and WS, Williams syndrome.

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  Figure 3. Autoregulatory adaptation of the cardiac output and downstream arterial resistance. A, Simulated CO (L/min) and central RPA/LPA flow splits (annotated). B, Negligible percent changes in CO and time‐averaged RPA flow attributed to downstream microvascular adaptation. AS indicates Alagille syndrome; CO, cardiac output; Extv, extensive intervention; LPA, left pulmonary artery; Pre, preintervention; Prox, proximal intervention; RPA, right pulmonary artery; and WS, Williams syndrome.

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  Figure 4. Simulated preinterventional and postinterventional hemodynamics (n=6). A, Simulated main, central right, and central left pulmonary artery (MPA, RPA, LPA) systolic and mean pressures (mm Hg). Line segments denote data from the same patient. B, Simulated body surface area (BSA)–indexed 3‐dimensional resistance (R3DxBSA), total pulmonary vascular resistance (PVRI; Wood units·m2), and right ventricular stroke work (RVSWI; cJ/m2). *P<0.05 with the Bonferroni correction. Extv indicates extensive intervention; Pre, preintervention; Prox, proximal intervention; PLPA, LPA pressure; PMPA, MPA pressure; and PRPA, RPA pressure.

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  Figure 5. Simulated preinterventional and postinterventional systolic pressure distributions at peak systole. Stent diameters are annotated. AS indicates Alagille syndrome; Extv, extensive intervention; Pre, preintervention; Prox, proximal intervention; and WS, Williams syndrome.

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  Figure 6. Preinterventional vessel segment resistances projected onto vessel centerlines. Regions with severe distal pulmonary artery lesions are highlighted and rotated for ease of display. AS indicates Alagille syndrome; WS, Williams syndrome; and WU, Wood units.