Pediatric Pulmonary Artery Research Articles

Clinical analysis of 145 cases of pediatric pulmonary artery sling diagnosed by echocardiography

Clinical analysis of 145 cases of pediatric pulmonary artery sling diagnosed by echocardiography

Variation and significance of serum microRNA-21 level in pediatric pulmonary artery hypertension associated with congenital heart disease.

This study strives to the variation and significance of microRNA-21 (miR-21) in children with congenital heart disease (CHD)-related pulmonary artery hypertension (PAH). Children with CHD (n = 179) were selected as subjects, including 101 children without PAH and 78 children with PAH. All children underwent general data collection, laboratory examination, echocardiography and cardiac catheterization. After detection of serum miR-21 expression, the predictive value and the impacts of serum miR-21 for PAH and postoperative critical illness were analyzed. Serum creatine kinase isoenzyme (CK-MB), B-type natriuretic peptide (BNP) and miR-21 were elevated, but ejection fraction (EF) and cardiac index (CI) were decreased in the CHD-PAH group. Serum miR-21 assisted in predicting PAH in CHD children, with the area under curve (AUC) of 0.801 (95% CI of 0.735∼0.857), a cut-off value of 2.56, sensitivity of 73.08, and specificity of 72.28%. Serum miR-21 in children with CHD-PAH was correlated with clinicopathological indicators such as systolic pulmonary artery pressure, mean pulmonary arterial pressure, BNP and CI. Serum miR-21 helped predict the development of postoperative critical illness in children with CHD-PAH, with an AUC of 0.859 (95% CI: 0.762-0.927, cut-off value: 4.55, sensitivity: 69.57%, specificity: 92.73%). Increased serum miR-21 was an independent risk factor of postoperative critical illness in children with CHD-PAH. Serum miR-21 was upregulated in children with CHD-PAH, which may serve as a predictive biomarker for the onset of PAH and postoperative critical illness in CHD children.

Computational simulation-derived hemodynamic and biomechanical properties of the pulmonary arterial tree early in the course of ventricular septal defects.

Untreated ventricular septal defects (VSDs) can lead to pulmonary arterial hypertension (PAH) characterized by elevated pulmonary artery (PA) pressure and vascular remodeling, known as PAH associated with congenital heart disease (PAH-CHD). Though previous studies have investigated hemodynamic effects on vascular mechanobiology in late-stage PAH, hemodynamics leading to PAH-CHD initiation have not been fully quantified. We hypothesize that abnormal hemodynamics from left-to-right shunting in early stage VSDs affects PA biomechanical properties leading to PAH initiation. To model PA hemodynamics in healthy, small, moderate, and large VSD conditions prior to the onset of vascular remodeling, computational fluid dynamics simulations were performed using a 3D finite element model of a healthy 1-year-old's proximal PAs and a body-surface-area-scaled 0D distal PA tree. VSD conditions were modeled with increased pulmonary blood flow to represent degrees of left-to-right shunting. In the proximal PAs, pressure, flow, strain, and wall shear stress (WSS) increased with increasing VSD size; oscillatory shear index decreased with increasing VSD size in the larger PA vessels. WSS was higher in smaller diameter vessels and increased with VSD size, with the large VSD condition exhibiting WSS >100 dyn/cm[Formula: see text], well above values typically used to study dysfunctional mechanotransduction pathways in PAH. This study is the first to estimate hemodynamic and biomechanical metrics in the entire pediatric PA tree with VSD severity at the stage leading to PAH initiation and has implications for future studies assessing effects of abnormal mechanical stimuli on endothelial cells and vascular wall mechanics that occur during PAH-CHD initiation and progression.

Feasibility and utility of dual-energy chest CTA for preoperative planning in pediatric pulmonary artery reconstruction.

The purpose of this study was to assess in pediatric pulmonary artery (PA) reconstruction candidates the feasibility and added utility of preoperative chest computed tomography angiography (CTA) using dual-energy technique, from which perfused blood volume (PBV)/iodine maps can be generated as a surrogate of pulmonary perfusion. Pediatric PA reconstruction patients were prospectively recruited for a new dose-neutral dual-energy CTA protocol. For each case, the severity of anatomic PA obstruction was graded by two pediatric cardiovascular radiologists in consensus using a modified Qanadli index. PBV maps were qualitatively reviewed and auto-segmented using Siemens syngo.via software. Associations between Qanadli scores and PBV were assessed with Spearman correlation (r) and ROC analysis. Effective radiation doses were estimated from dose-length product and ICRP 103k-factors, using cubic Hermite spline interpolation. 19 patients were recruited with mean (SD) age of 6.0 (5.1), 11 (57.9%) female, 11 (73.7%) anesthetized. Higher QS correlated with lower PBV, both on a whole lung (r = - 0.54, p < 0.001) and lobar (r = - 0.50, p < 0.001) basis. The lung with lowest absolute PBV was predictive of the lung with highest Qanadli score, with AUC of 0.70 (95% CI 0.47-0.93). Qualitatively, PBV maps were heterogeneous, corresponding to multifocal PA stenoses, with decreased iodine content in areas of most severe obstruction. In conclusion, dual-energy chest CTA is feasible for pediatric PA reconstruction candidates. PBV maps show deficits in regions of more severe anatomic obstruction and may serve as a novel biomarker in this population.

Echocardiography in diagnosis of pediatric pulmonary artery sling

To evaluate the application of echocardiography in diagnosis of pediatric pulmonary artery sling. Twenty-five children diagnosed as pulmonary artery sling in the Children's Hospital, Zhejiang University School of Medicine from July 2012 to August 2017, and 50 healthy children(control group) were enrolled in the study. Echocardiography was performed in all subjects. The origins of the left pulmonary artery(LPA) and right pulmonary artery(RPA) were observed; the internal diameters of LPA, RPA and main pulmonary artery(MPA) were measured; and the ratios of LPA/MPA and RPA/MPA were calculated. The value of RPA/MPA and LPA/MPA in diagnosing pulmonary artery sling was evaluated by ROC curve. Echocardiography showed that the internal diameters of RPA were increased in all patients; while the LPA and blood flow signals in common pulmonary arterial bifurcation were not found in 24 cases, in whom the MPA was directly extended to the RPA, and the LPA was from the massive RPA. The ultrasound of one special case showed that there was no distinct bifurcation of MPA; the MPA walked to the right and then to the left with no change in the internal diameter. There were significant differences in RPA/MPA(0.50±0.05 vs. 0.71±0.15, t=7.06, P<0.01) and LPA/MPA(0.52±0.05 vs. 0.39±0.09, t=6.94, P<0.01) between controls and the patients. ROC curve analysis showed that the AUC of RPA/MPA and LPA/MPA in diagnosis of pulmonary artery sling were 0.90 and 0.89, respectively. When taking 0.60 as the cutoff value, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of RPA/MPA in diagnosis of pulmonary artery sling were 79%, 100%, 100%, 91% and 93%, respectively. When taking 0.43 as the cutoff value, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of LPA/MPA in diagnosis of pulmonary artery sling were 71%, 96%, 89%, 87% and 88%, respectively. s Echocardiography can effectively diagnose pediatric pulmonary artery sling. The RPA/MPA ratio of 0.60 and the LPA/MPA ratio of 0.43 can be used as cutoff values for diagnosis.

Pediatric Pulmonary Artery Rehabilitation: A Review of Our Experience and a Novel Approach Using Bronchial Blockers.

Recent advances in the field of pediatric interventional cardiology have resulted in therapies for patients in need of augmented pulmonary artery (PA) flow. Catheter-based PA rehabilitation can be performed safely but not without the potential risk of pulmonary hemorrhage. When severe, this bleeding has the ability to contaminate the bronchi and trachea, and possibly occlude the endotracheal tube. This can result in a critical inability to ventilate and oxygenate these patients. Herein, we review our institutional experience with pulmonary hemorrhage associated with these procedures and the feasibility of predicting this outcome. The secondary aim was to discuss our novel anesthetic approach to a select group of these patients, involving the use of bronchial blockers to preemptively prevent contamination of bilateral bronchi and occlusion of the endotracheal tube.

First Successful Clinical Application of the In Vivo Tissue-Engineered Autologous Vascular Graft

The ideal material for pediatric pulmonary artery (PA) augmentation is autologous pericardium. However, its utility for multistaged operations is limited. In this study, we applied an in vivo tissue-engineered autologous Biotube graft to a patient with congenital heart disease for the first time. For molds of the Biotubes, two silicone 19F drain tubes were embedded in the subcutaneous spaces of a 2-year-old girl with a diagnosis of pulmonary atresia and ventricular septal defect with major aortopulmonary collateral arteries during palliative surgical procedures. When definitive repair was performed after 8 months, the implants were removed to prepare Biotubes, one of which was cut open and autologously implanted into the PA for patch augmentation. Seven months after implantation, the Biotube patch-augmented PA tolerated balloon angioplasty (BAP) for residual stenosis of the peripheral PA. Computed tomography images after BAP showed the well-preserved shape of the Biotube patch-augmented PA. Neither aneurysm formation nor stenosis was observed. The safety and feasibility of Biotubes for pediatric PA patch augmentation are described. Because Biotubes are completely autologous, they may be ideal material for pediatric PA augmentation.

Abnormalities in Echocardiographic Indices of Right- and Left-Ventricular Systolic Function in Pediatric Pulmonary Artery Hypertension

Abnormalities in Echocardiographic Indices of Right- and Left-Ventricular Systolic Function in Pediatric Pulmonary Artery Hypertension

Abstract 18705: Simian Immunodeficiency Virus Induces Pulmonary Arterial Hypertension in Rhesus Macaques: A Hemodynamic Study

Background: Our prior studies have shown that the Cyno Macaques and Resus Macaques infected with simian immunodeficiency virus (SIV) develop pulmonary arterial hyperplasia by histopathology. The hemodynamic changes with infection, however, remain unknown. The purpose of this study was to determine the relationship of the SIV infection and cardiac hemodynamic changes as assessed by invasive right heart catheterization. Methods: Five Rhesus macaques underwent pulmonary artery catheterization at baseline and 6 months after infection with SIV. Right atrial pressure (RAP), right ventricular end systolic pressure (RVESP), end diastolic pressure (RVEDP), and mean pulmonary artery pressure (mPAP) were measured directly using a pediatric pulmonary artery catheter. RV dp/dt min, dp/dt max, Tau and contractility index were calculated by Matlab software. In addition, mPAP was calculated in a larger cohort (n=24) by the regression formula: mPAP=RVSP*0.65+0.55 in order to validate this calculation in non-human primates. Results: After 6 months of SIV infection, RAP, RVSP, and mPAP increased significantly compared to baseline values. RVEDP trended toward being higher but was not statistically significant from baseline. The RV dp/dt min, dp/dt max and Tau didn’t show significant changes. The contractility index had a markedly decrease with SIV infection compared with baseline. Moreover, direct measure mPAP correlated well with the calculation of mPAP (R 2 =0.954; P&lt;0.0001). Conclusion: Based on the presented data we conclude that SIV induces pulmonary arterial hypertension in Rhesus monkeys concordant with the histopathological observation in our prior studies. SIV infection also decreases the RV contractility as well. These data suggest that this may be a viable large animal, preclinical model of PAH with hemodynamics and histology consistent with the human condition.

Mechanical analysis of ovine and pediatric pulmonary artery for heart valve stent design

Transcatheter heart valve replacement is an attractive and promising technique for congenital as well as acquired heart valve disease. In this procedure, the replacement valve is mounted in a stent that is expanded at the aimed valve position and fixated by clamping. However, for this technique to be appropriate for pediatric patients, the material properties of the host tissue need to be determined to design stents that can be optimized for this particular application. In this study we performed equibiaxial tensile tests on four adult ovine pulmonary artery walls and compared the outcomes with one pediatric pulmonary artery. Results show that the pediatric pulmonary artery was significantly thinner (1.06±0.36mm (mean±SD)) than ovine tissue (2.85±0.40mm), considerably stiffer for strain values that exceed the physiological conditions (beyond 50% strain in the circumferential and 60% in the longitudinal direction), more anisotropic (with a significant difference in stiffness between the longitudinal and circumferential directions beyond 60% strain) and presented stronger non-linear stress–strain behavior at equivalent strains (beyond 26% strain) compared to ovine tissue. These discrepancies suggest that stents validated and optimized using the ovine pre-clinical model might not perform satisfactorily in pediatric patients. The material parameters derived from this study may be used to develop stent designs for both applications using computational models.

Validation of cardiac output measurement by ultrasound dilution technique with pulmonary artery thermodilution in a pediatric animal model.

Novel COstatus system (Transonic Systems, Inc., NY), based on ultrasound dilution (UD), works off in situ arterial and central venous catheters in pediatric patients to measure cardiac output (CO). The purpose of the present study was to validate CO measurement by UD (COUD) with pulmonary artery (PA) thermodilution (COTD) in a prospective animal study. Ten anesthetized pigs (16-45 kg) were instrumented with pediatric PA, central venous, and peripheral artery catheters. For COUD measurements, normothermic saline (0.5-1.0 ml/kg body weight, up to a maximum of 30 ml) was injected into the venous limb of an arteriovenous loop that was connected between in situ catheters. For COTD measurements, 5-10 ml cold saline was injected into the PA catheter. Sixty-four averaged sets were obtained for comparison. COTD mean was 2.98 ± 1.21 l/min (range 1.33-6.29), and COUD mean was 2.68 ± 1.16 l/min (range 1.33-5.85). This study yielded a correlation r = 0.96, COUD = 0.91*(COTD) - 0.04 l/min; bias was 0.3 l/min with limits of agreement as -0.39 to 0.99 l/min; and the percentage error was 23.73% between the methods. CO measurements by UD agreed well with thermodilution measurements in the pediatric swine model.

Use of intravascular ultrasound to measure local compliance of the pediatric pulmonary artery: In vitro studies

Background: The accurate measurement of local pulmonary artery compliance in pediatric pulmonary hypertension is an important step toward further understanding the biomechanical and hemodynamic aspects of the disease. The emergence of intravascular ultrasound (IVUS) imaging techniques promises the ability to make such measurements clinically. However, the use of IVUS for compliance measurements has not been validated. Furthermore, confusion exists regarding the most appropriate method to measure compliance. Methods: This study validated IVUS measurements against a laser micrometer standard for 4 elastic tubes of varying compliance. Two methods of quantifying local compliance were explored: The pressure-strain modulus (Ep),(Ep(g/cm2) = ΔP × Rd/ΔR (Where ΔP is pulse pressure, Rd is diastolic radius, and ΔR is systolic minus diastolic radii) and the dynamic compliance (Cdyn),(Cdyn(%/100 mm Hg) = [ΔD/(ΔP × Dd)] × 104 Where ΔD is systolic minus diastolic diameters and Dd is diastolic diameter. Results: IVUS diameter measurements agreed well with laser micrometer data although slight overestimation (mean = 3.67% ± 2.78%) was present. Mean values of Ep ranged from 353.3 g/cm2 to 2676.0 g/cm2; mean Cdyn values ranged from 5.7% diametric change/100 mm Hg to 39.5% diametric change/100 mm Hg for all tube models. Although mean values of Ep and Cdyn could be distinguished among the various tubes, the extremely large measurement uncertainty for Ep precluded statistical differentiation. The uncertainty in Ep increased inversely with the diametric change, indicating a potential limitation of Ep associated with stiffening arteries. Conclusions: We conclude that Cdyn is a more robust mean of quantifying pediatric pulmonary artery compliance, especially as arteries stiffen with chronic pulmonary hypertension. (J Am Soc Echocardiogr 2002;15:1507-14.)

Migration of Pediatric Pulmonary Artery Catheters

Migration of Pediatric Pulmonary Artery Catheters

Age-related changes in the mechanics of the aorta and pulmonary artery of man.

Age-related changes in the mechanics of the aorta and pulmonary artery of man.