Pulmonary atresia

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Classification according to ICD-10
Q25.5 Pulmonary artery atresia
ICD-10 online (WHO version 2019)

The pulmonary atresia belong to the complex cyanotic congenital heart malformations and belong to the complex of the single ventricle . The term simplifies the common characteristic of this group of heart defects: the pulmonary valve (the connection from the right ventricle to the pulmonary artery) is closed. A distinction is made between the two large subgroups with and without a ventricular septal defect . The effects on the cardiovascular system and the therapeutic approach are different.

Pulmonary atresia with an intact ventricular septum

The pulmonary valve is closed and the blood flows

  1. from the right ventricle back into the right atrium / via the foramen ovale into the left atrium (right-left shunt ) / into the left ventricle / into the aorta / partly via the ductus arteriosus into the pulmonary artery / is oxygenated in the lungs loading / reaching the left atrium and left ventricle normally. The life of the child (without treatment) therefore depends on the prenatal connections “foramen ovale” and “ductus arteriosus”. If the "ductus arteriosus" closes (usually first), less blood flows this way. The child quickly becomes deprived of oxygen .
  2. The second “detour” is not always available. These are the prenatal connections between the inside of the right ventricle and the coronary arteries (so-called myocardial sinusoids) that run on the outside of the muscles. The greatly increased pressure in the right ventricle, which exceeds the pressure in the left ventricle and the aorta , makes this detour possible. From the coronary vessels, the blood flows partly “against the current” into the aorta, partly with the current into the heart muscles, into the coronary veins and then into the right atrium. The high pressure in the right ventricle is caused by a massively thickened musculature (myocardial hypertrophy), which is why the interior space is often reduced and the endocardium is also thickened. In addition, the tricuspid valve in its muscular outlet or parts of the pulmonary artery are often narrowed or closed.

Pulmonary atresia with an intact ventricular septum is therefore often a disease of the entire right heart. The child's survival (without treatment) is dependent on the prenatal connections described above.

therapy

Keeping the "ductus arteriosus" open with prostaglandin until an operation. Then there are the following options

  • Creation of an aorto-pulmonary shunt
  • the closed pulmonary valve is opened surgically or interventionally . During the intervention, a special cardiac catheter (radiofrequency ablation catheter) is used to “burn” a hole in the closed valve and then expand it with a balloon catheter.
  • the "ductus arteriosus" is kept open by inserting a stent .

The decision to proceed depends on the anatomy and practical experience of the treating center. The long-term goal is to create a largely normal circulatory system, which is theoretically achieved in a small number of patients by opening the closed pulmonary valve. In the vast majority of cases, however, a Fontan operation is performed.

Pulmonary atresia with ventricular septal defect

The pulmonary valve is closed. There is a ventricular septal defect . The oxygen-poor blood flows through this defect into the aorta via the left ventricle . The result is a cyanosis . The blood takes the following detour:

  1. The blood from the aorta can (rarely) enter the pulmonary artery system via a ductus arteriosus .
  2. More often and typically, the pulmonary artery is reached via collaterals (bypass vessels between the aorta and the pulmonary vascular system, which normally have already receded at birth). There can be a different number of them with different origins and mouths.

The pulmonary vascular system is often underdeveloped beyond the closed pulmonary valve (hypoplastic) or a central part of the pulmonary artery is missing, so that not all segments of the lungs are connected (rarely). After opening the pulmonary valve, the respective lung segment can then have normal, reduced or increased blood flow.

The children with this clinical picture are often only slightly or not at all impaired in the first weeks or months of life. The cyanosis can be minor if the collaterals are sufficient to provide adequate blood flow to the lungs and adequate oxygen saturation .

therapy

Several surgical and interventional interventions are to be expected, since the correction of the closed pulmonary valve (possibly with a homograft = human donor valve) and the ventricular septal defect is only really sufficient in very few cases. The main problem is often the pulmonary vasculature, which is improved with complicated surgical measures. The therapeutic measures depend on the individual findings.

Diagnosis

Long-term expectations

Today, children usually reach adolescence and adulthood with a good quality of life. Follow-up treatments depend on the further development of the cardiovascular system. Lifelong check-ups and strict observance of endocarditis prophylaxis must be observed.

literature

Web links