Pulmonary atresia with intact ventricular septum and right ventricular dependent coronary circulation through the "vessels of Wearn"

A surgical mouse model of neonatal right ventricular outflow tract obstruction by pulmonary artery banding

BACKGROUD

Diseased animal models play an extremely important role in preclinical research. Lacking the corresponding animal models, many basic research studies cannot be carried out, and the conclusions obtained are incomplete or even incorrect. Right ventricular (RV) outflow tract (RVOT) obstruction leads to RV pressure overload (PO) and reduced pulmonary blood flow (RPF), which are 2 of the most important pathophysiological characteristics in pediatric cardiovascular diseases and seriously affect the survival rate and long-term quality of life of many children. Due to the lack of a neonatal mouse model for RVOT obstruction, it is largely unknown how RV PO and RPF regulate postnatal RV and pulmonary development. The aim of this study was to construct a neonatal RVOT obstruction mouse model.

METHODS AND RESULTS

Here, we first introduced a neonatal mouse model of RVOT obstruction by pulmonary artery banding (PAB) on postnatal day 1. PAB induced neonatal RVOT obstruction, RV PO, and RPF. Neonatal RV PO induced cardiomyocyte proliferation, and neonatal RPF induced pulmonary dysplasia, the 2 features that are not observed in adult RVOT obstruction. As a result, PAB neonates exhibited overall developmental dysplasia, a sign similar to that of children with RVOT obstruction.

CONCLUSIONS

Because many pediatric cardiovascular diseases are associated with RV PO and RPF, the introduction of a neonatal mouse model of RVOT obstruction may greatly enhance our understanding of these diseases and eventually improve or save the lives of many children.

Pulmonary Atresia With Ventriculocoronary Arterial Connections and a Large Conoventricular Septal Defect

Ventriculocoronary arterial connections are typically found in patients with pulmonary atresia with an intact ventricular septum. This report describes a case of ventriculocoronary arterial connections in a patient with pulmonary atresia with a ventricular septal defect. Our case supports recent data suggesting a primary coronary artery developmental anomaly in pulmonary atresia. (Level of Difficulty: Advanced.)

Percutaneous obliteration of the right ventricle to avoid coronary damage by sinusoids in patients with pulmonary atresia intact ventricular septum during staged single ventricle palliation

BACKGROUND AND AIMS

Suprasystemic pressure waves can damage the coronary arteries resulting in myocardial ischemia and excess early mortality. We aimed to reduce the coronary pressure wave through the sinusoids by abolishing RV volume with percutaneous devices.

METHODS AND RESULTS

Four patients with PA-IVS and coronary sinusoids from the hypertensive rudimentary RV were evaluated at a median age 26.6 months (range: 2.7-51.7). Right ventricle coronary dependent flow to the left ventricular myocardium was excluded. All four patients had dual perfusion with competitive flow from the RV through the sinusoids to the coronary arteries. Devices used were: Amplatzer vascular plug II of 10-16 mm; 27 coils (diameter 5-15 mm) in the oldest patient. Right ventricular angiography after cavity obliteration showed no more significant coronary perfusion through the sinusoids. There were no complications or deaths. Only minor and transient changes in the levels of troponin were observed. Coronary angiography at pre-Fontan evaluation showed no progress of coronary abnormalities in two patients.

CONCLUSION

In selected patients with functionally single left ventricle, obliteration of the hypertensive RV cavity by percutaneous devices is safe and abolishes the systolic pressure wave in coronary sinusoids. When performed early, this may halt coronary damage and avoid excess mortality.

Prenatal echocardiographic classification and prognostic evaluation strategy in fetal pulmonary atresia with intact ventricular septum

Fetal pulmonary atresia with intact ventricular septum (PA/IVS) is a rare congenital heart disease. The present study aimed to classify PA/IVS and determine the relationship between prenatal echocardiographic characteristics and postnatal biventricular or univentricular repair strategies.A total of 51 fetuses with PA/IVS were examined from 2012 to 2019. Data on prenatal echocardiography, associated anomaly, karyotype, and outcome were collected. Two-dimensional measurements included tricuspid valve (TV) z-score, mitral valve (MV) z-score, TV/MV ratio, and ratio of right to left ventricle (RV/LV) length, whereas color Doppler measurements included degree of tricuspid regurgitation (TR), ventriculo-coronary artery communication (VCAC), tricuspid inflow duration (TID), cardiac cycle duration (CCD), middle cerebral artery pulsatility index (MCA PI), and umbilical artery pulsatility index (UA PI). Diagnostic classification was based on the development of RV and the presence or absence of VCAC. Postnatal evaluation was divided according biventricular or univentricular repair.Of the 51 fetuses with PA/IVS, 20 were type I, 17 were type II, and 14 were type III. Only one fetus exhibited right aortic arch. The karyotype of all the fetuses was normal. Of the 28 patients who underwent postnatal surgery, 13 (46%) underwent biventricular repair and 15 (54%) underwent univentricular repair. TV z-score was significantly higher for the biventricular repair group compared with univentricular repair group (-1.20 ± 0.98 vs -4.33 ± 0.80, P = .000). TV/MV, RV/LV length, and TID/CCD were significantly higher for the biventricular repair group than the univentricular repair group (0.81 ± 0.14 vs 0.54 ± 0.09, 0.71 ± 0.11 vs 0.49 ± 0.09, 39.20 ± 3.84 vs 29.16 ± 4.58, P = .000). Moderate or severe TR and VCAC were significantly different between the 2 groups (P = .000). Gestational age, MCA PI, and UA PI did not differ between the 2 groups (P = .72, P = .36, P = .06). The cutoff values for the biventricular repair characteristic curves were TV z-score >-3.28, TV/MV ratio >0.71, RV/LV length >0.62, and TID/CCD >33.95%. The sensitivities of the TV z-score, TV/MV, RV/LV length, and TID/CCD were 100%, 77%, 85%, and 92%, respectively. The specificities of the TV z-score, TV/MV, RV/LV length, and TID/CCD were 94%, 100%, 100%, and 94%, respectively.Fetal echocardiography was able to classify PA/IVS according to variable degree of RV and VCAC. In fetal PA/IVS, TV z-score >-3.28, TV/MV >0.71, RV/LV length >0.62, TID/CCD >33.95%, moderate and severe TR, and the absence of VCAC were associated with postnatal biventricular repair strategy. These findings may have implications for prenatal counseling and prediction of fetal outcome.

Mechanical and microstructural analysis of a radially expandable vascular conduit for neonatal and pediatric cardiovascular surgery

In pediatric cardiovascular surgery, there is a significant need for vascular prostheses that have the potential to grow with the patient following implantation. Current clinical options consist of nonexpanding conduits, requiring repeat surgeries as the patient outgrows the device. To address this issue, PECA Labs has developed a novel ePTFE vascular conduit with the capability of being radially expanded via balloon catheterization. In the described study, a systematic characterization and comparison of two proprietary ePTFE expandable conduits was conducted. Conduit sizes of 8 and 16 mm inner diameters for both conduits were evaluated before and after expansion with a 26 mm balloon. Comprehensive mechanical testing was completed, including quantification of circumferential, and longitudinal tensile strength, suture retention strength, burst strength, water entry pressure, dynamic compliance, and kink radius. Scanning electron microscopy was used to investigate the microstructural properties. Automated extraction of the fiber architectural features for each scanning electron micrograph was achieved with an algorithm for each conduit before and after expansion. Results showed that both conduits were able to expand significantly, to as much as 2.5× their original inner diameter. All mechanical properties were within clinically acceptable values following expansion. Analysis of the microstructure properties of the conduits revealed that the circumferential main angle of orientation, orientation index, and spatial periodicity did not significantly change following expansion, whereas the node area fraction decreased post expansion. Successful proof-of-concept of this novel product represents a critical step toward clinical translation and provides hope for newborns and growing children with congenital heart disease. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 659-671, 2018.

Coil occlusion of aberrant arteries to pulmonary sequestration in a case with pulmonary atresia with intact ventricular septum: successful treatment of repetitive myocardial ischaemic attacks

In this study, we describe an infant case of pulmonary atresia with intact ventricular septum associated with ventriculo-coronary arterial communication for which a modified Blalock-Taussig shunt operation was performed. He experienced repeated myocardial ischaemic attacks. Further examination revealed pulmonary sequestration in the right lower lobe. He therefore underwent a bidirectional Glenn operation and coil occlusion of the feeding arteries. His myocardial ischaemic attacks subsequently improved.

Association of coronary to left ventricular microfistulae (vessels of Wearn) with atrial septal defect in an adult without cyanotic heart disease

Vessels of Wearn are rare findings during coronary angiography in adults. They are known to be associated with forms of cyanotic congenital heart disease in infants but we are not aware of any published cases of association with non-cyanotic left to right shunts in adults. We present the case of a 69-year-old man with angiographically evident vessels of Wearn draining from the left and right coronary arteries into the left ventricle associated with an asymptomatic atrial septal defect. We postulate a developmental phase association between atrial septal maturation and closure of perfusing microchannels from the ventricular cavities to the epicardial coronary arteries on the same spectrum as that which leads to more widespread defects in infants. We also highlight a common medication side effect that might have been mistaken as a manifestation of the congenital anomalies.

Prenatal diagnosis of multiple ventriculocoronary connections in pulmonary atresia with an intact ventricular septum: a case report

We report a case of prenatally detected pulmonary atresia with an intact ventricular septum accompanied by multiple ventriculocoronary connections. This lesion was diagnosed by using ultrasonography at 20 weeks' gestation, and this antepartum diagnosis was confirmed with both postnatal echocardiography and chest computed tomography. The neonate underwent a modified Blalock-Taussig shunt on the 15th day of life, and was discharged 8 days after the surgery.