Pulmonary ductal coarctation and left pulmonary artery interruption; pathology and role of neural crest and second heart field during development

Total Anomalous Pulmonary Venous Connections, Human Genetics

Partial anomalous pulmonary venous connections (PAVC) have been found after abnormal gene expressions involving several syndromes. Total anomalous pulmonary venous connection (TAPVC) is found in conjunction with heterotaxia syndrome as well as several other syndromes. It has been reported with an autosomal dominance with variable expression and incomplete penetrance. The occurrence is also related to environmental factors which may superimpose on a familial susceptibility for TAPVC. Many pathways are involved in the normal development of the pulmonary venous connections and as a consequence disturbance of many genetic and epigenetic pathways lead to partial or total pulmonary venous misconnections. In this chapter, an overview of current knowledge regarding human genetics of anomalous venous connections is provided.

When to intervene the pulmonary artery: Importance of anatomical assessment in the diagnosis of pulmonary artery coarctation

OBJECTIVE

Pulmonary artery coarctation (PACoA) is a major problem that increases the frequency of intervention. However, there is little evidence regarding the prediction of PACoA development.

METHODS

A retrospective chart review was performed on 42 patients who underwent modified Blalock-Taussig shunt and preoperative contrast-enhanced computed tomography. An uneven PA branching was defined as an abnormal ductus arteriosus connection to the left PA distal to the PA branching on contrast-enhanced computed tomography.

RESULTS

Nineteen (45.2%) of 42 patients were diagnosed with PACoA. The median diameters of the ductus on the aorta and PA sides were 4.1 mm and 3.6 mm in the PACoA group and 3.6 mm and 2.9 mm in the non-PACoA group, respectively (P = .07 and .28, respectively). Tortuous ductus was recognized in 7 (36.8%) patients in the PACoA group and 14 (60.8%) patients in the non-PACoA group (P = .12). PACoA was associated with pulmonary atresia (16 patients [84.2%] in the PACoA group and 12 patients [52.1%] in the non-PACoA group) (P = .02). All 19 patients had uneven PA branching in the PACoA group, whereas 5 of 23 (21.7%) patients had uneven PA branching in the non-PACoA group (P < .001).

CONCLUSIONS

Uneven PA branching rather than the ductus arteriosus size was strongly associated with PACoA development; therefore, morphologic assessment by contrast-enhanced computed tomography should be considered in patients with pulmonary atresia.

Left Pulmonary Artery Coarctation Associated with Pneumonia and Pulmonary Hypertension in a Cat

A five-month-old European shorthair female kitten was referred because of recurrent episodes of respiratory distress. Results of physical examination, thoracic radiography, and echocardiography led to a presumptive diagnosis of severe precapillary pulmonary hypertension (PH) and interstitial pneumonia associated with right-sided cardiac remodeling. The cat rapidly died because of respiratory insufficiency. Pulmonary and cardiovascular pathological findings evidenced left pulmonary artery coarctation, severe right-sided cardiac hypertrophy, and bilateral pneumonia. This is the first report of pulmonary artery coarctation associated with pneumonia and PH in a cat.

Ventricular Septation and Outflow Tract Development in Crocodilians Result in Two Aortas with Bicuspid Semilunar Valves

Background: The outflow tract of crocodilians resembles that of birds and mammals as ventricular septation is complete. The arterial anatomy, however, presents with a pulmonary trunk originating from the right ventricular cavum, and two aortas originating from either the right or left ventricular cavity. Mixing of blood in crocodilians cannot occur at the ventricular level as in other reptiles but instead takes place at the aortic root level by a shunt, the foramen of Panizza, the opening of which is guarded by two facing semilunar leaflets of both bicuspid aortic valves. Methods: Developmental stages of Alligator mississipiensis, Crocodilus niloticus and Caiman latirostris were studied histologically. Results and Conclusions: The outflow tract septation complex can be divided into two components. The aorto-pulmonary septum divides the pulmonary trunk from both aortas, whereas the interaortic septum divides the systemic from the visceral aorta. Neural crest cells are most likely involved in the formation of both components. Remodeling of the endocardial cushions and both septa results in the formation of bicuspid valves in all three arterial trunks. The foramen of Panizza originates intracardially as a channel in the septal endocardial cushion.

Pulmonary ductal coarctation: An entity associated with congenital heart defects involving the right ventricle outflow tract

We present a case of a prematurely born 2‐month‐old girl with a double outlet right ventricle with pulmonary atresia and a left pulmonary artery coarctation arising after ductal closure. The case highlights the importance of knowledge and identification of such an anomaly in patients with congenital heart malformations with severe pulmonary stenosis to atresia.

RNA sequencing analyses in infants patients with coarctation of the aorta

BACKGROUND

Coarctation of the aorta (CoA) is a serious innate heart disease. Although surgery results are generally good, some complications such as recoarctation and aortic aneurysm or persistent hypertension were serious threats to patient's health. To better understand the pathology of CoA and its underlying molecular mechanism is particularly important for early diagnosis and preventing the occurrence of its complications. However, the mechanisms of CoA remain unclear, especially for infants.

METHODS

RNA sequencing (RNA-seq) was used to identify the differentially expressed genes (DEGs) in vascular tissues of 12 patients with CoA and 10 normal participants form 3- to 34-month-old infants. The characteristic of DEGs were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunochemical staining (IHC) in vessels of patients with CoA and normal infants.

RESULTS

A total of 2491 DEGs with the false discovery rate less than 0.05(> 1.5-fold, P < 0.05 change) were identified, including 443 upregulated genes and 2048 downregulated genes. The Gene Ontology enrichment analysis showed that 26 out of the 2491 DEGs identified were associated with cardiovascular diseases. These 26 genes were mainly associated with extracellular matrix (ECM) and smooth muscle cells (SMCs) differentiation. Three DEGs, that is, CNN1 (calponin), α-actinin1 and myosin heavy chain 11 MYH11, were validated using qRT-PCR and Western blot analysis. In addition, immunochemical staining showed that calponin and MYH11 were highly expressed on the surface and in the deep layers of the thickened intima respectively.

CONCLUSION

This study comprehensively characterized the CoA transcriptome. Migration of extracellular matrix (ECM) and smooth muscle cells (SMCs) to the subendothelial space may be the major characteristic of CoA in infants.

Isolated Dissection of the Ductus Arteriosus Associated with Sudden Unexpected Intrauterine Death

We report five cases of sudden intrauterine death due to premature closure of the ductus arteriosus. In four cases, this was caused by dissecting the hematoma of the ductus arteriosus with intimal flap and obliteration of the lumen. In one case, the ductus arteriosus was aneurysmatic, with lumen occlusion caused by thrombus stratification. No drug therapy or free medication consumption were reported during pregnancy. The time of stillbirth ranged between 26 and 33 gestational weeks. We performed TUNEL analysis for apoptosis quantification. The dissecting features were intimal tears with flap formation in four of the cases, just above the origin of the ductus arteriosus from the pulmonary artery. The dissecting hematoma of the ductus arteriosus extended downward to the descending aorta and backward to the aortic arch with involvement of the left carotid and left subclavian arteries. TUNEL analysis showed a high number of apoptotic smooth muscle cells in the media in two cases. Abnormal ductal remodeling with absence of subintimal cushions, lacunar spaces rich in glycosaminoglycans (cystic medial necrosis), and smooth muscle cell apoptosis were the pathological substrates accounting for failure of remodeling process and dissection.

Fontan-Associated Anatomical Variants and Hepatic Fibrosis

OBJECTIVE

We hypothesized that a relationship between post-Fontan hepatic fibrosis and anatomical variants might exist.

METHODS

Attempting to limit confounding variables, we analyzed data from living, stable, post-extracardiac Fontan patients who underwent cardiac catheterization and transvenous hepatic biopsy procedures between March 2012 and June 2020.

RESULTS

We identified 120 patients who met the inclusion criteria. Of the 120, 35 (29%) had pulmonary artery stents. For the 35 with pulmonary artery stents, the average total fibrosis score was 3.2 ± 1.9 and the fibrosis progression rate was 0.36 ± 0.33, and for those with no pulmonary artery stents, the total fibrosis score was 2.6 ± 1.8 and the fibrosis progression rate was 0.27 ± 0.33 (P = .13 and P = .11, respectively). Of the 120, 65 had functional univentricles of right ventricular type. Of these 65, 27 had pulmonary artery stents. For the 27 with pulmonary artery stents, the average total fibrosis score was 3.4 ± 1.8 and the average fibrosis progression rate was 0.39 ± 0.30, and for the 38 without pulmonary artery stents, the average fibrosis score was 2.3 ± 1.5 and the average fibrosis progression rate was 0.23 ± 0.21 (P = .01 for comparison of both values).

CONCLUSIONS

This study's findings suggest that a post-extracardiac Fontan with a functional univentricle of right ventricular type plus a pulmonary artery stent may have more advanced liver pathology than those without a pulmonary artery stent at similar Fontan duration years and ages at liver biopsy.

Left pulmonary arterial branch interruption with concurrent coarctation of the right pulmonary artery in a dog

This case report describes a rare disorder of a left pulmonary artery interruption with concurrent coarctation of the right pulmonary artery in a dog. A 5-year-old, male neutered, mixed-breed dog presented for evaluation of an asymptomatic heart murmur. Echocardiography and computed tomography revealed complete interruption of the proximal left pulmonary artery and coarctation of the right pulmonary artery. Collateral circulation to the left lung field was provided by a dilated bronchoesophageal artery with evidence of left pulmonary hypoplasia. Pulmonary artery interruption and coarctation is rarely reported in the veterinary literature.