The method of surgical correction of partial abnormal drainage of the pulmonary veins is determined by the type of defect: this takes into account the level of drainage, the size and location of DMPP.
Depending on the criteria mentioned above, numerous variants of replantation of the mouths of the pulmonary veins or their common collectors into the left atrium are used.
To eliminate the interatrial message, closure or DMPP is made.
Children under the age of 3 months who are in critical condition undergo a palliative operation of a closed atrioseptotomy aimed at increasing the interatrial message.
The general principles of radical correction of the total abnormal drainage of the pulmonary veins include: creating an anastomosis between the pulmonary veins and the left atrium, closing DMPP, ligation of the pathological message of the pulmonary veins with venous vessels. After surgery, a sick sinus syndrome may develop, an increase in pulmonary hypertension associated with inadequate provision of outflow pathways from the pulmonary veins.
Abnormal drainage of the pulmonary veins is a congenital heart disease in which the mouth of all or individual pulmonary veins flows into the right atrium, coronary sinus or vena cava. Abnormal drainage of the pulmonary veins is 1.5-3% of all CHD in cardiology, with a predominance in males.
Most often, abnormal pulmonary vein drainage is combined with atrial septal defect and an open oval window; in 20% of cases – with a common arterial trunk, VSD, transposition of the great vessels, Fallo’s notebook, stenosis of the pulmonary artery, hypoplasia of the left heart, a single ventricle, dextrocardia.
From extracardiac pathology in patients with abnormal pulmonary vein drainage, intestinal diverticula, umbilical hernia, polycystic kidney disease, hydronephrosis, horseshoe kidney, and various bone and endocrine systems malformations are found.
Causes of anomalous pulmonary vein drainage
The common causes that form anomalous drainage of pulmonary veins do not differ from those of other CHD.
Direct dissociation of the pulmonary veins with the left atrium may be due to two factors: the lack of their connection or early atresia of the common pulmonary vein. In the first case, under the influence of adverse conditions, the left atrial outgrowth is not properly associated with the venous plexuses of the lung bud, which leads to the formation of anomalous venous drainage.
In case of early atresia, the initial connection of the common pulmonary vein and the pulmonary vascular bed takes place; however, their lumen obliterates later, and therefore the venous pulmonary return begins to occur through other available collateral pathways.
Classification of anomalous pulmonary vein drainage
When the mouths of all the pulmonary veins fall into the venous system of the pulmonary circulation or right atrium, they indicate a complete (total) anomalous drainage of the pulmonary veins.
If one or more pulmonary veins are drained into the right atrium or large circle, this form of defect is called partial. Most often (in 97% of cases) the veins extending from the right lung are abnormally drained.
Based on the level of inflow of the pulmonary veins, anomalous drainage is classified into 4 anatomical types (option).
- I option – supracardial (nadserdechny). The pulmonary veins are drained by a common collector or separately into the superior vena cava or its branches (unpaired vein, left untitled or additional superior vena cava).
- Option II – intracardial (cardiac). Abnormal drainage of the pulmonary veins occurs in the right atrium or coronary sinus.
- III variant – subcardial, infracardiac (subcardiac). The pulmonary veins flow into the inferior vena cava or portal vein (rarely into the lymphatic duct).
- IV version – mixed. Abnormal drainage of the pulmonary veins into the venous system is carried out at various levels in various combinations.
Features of hemodynamics during abnormal drainage of pulmonary veins
In the antenatal period, the defect usually does not have hemodynamic manifestations, since the intracardiac circulation of the fetus implies the flow of blood from the right atrium into the left (through the open oval window) and into the canal duct. After birth, the severity of hemodynamic disturbances determines the form (full or partial), the variant of anomalous pulmonary vein drainage, and the combination of a defect with other heart defects.
From the point of view of hemodynamics, the total abnormal drainage of the pulmonary veins is characterized by the fact that all oxygenated blood from the lungs falls into the right atrium, where it is mixed with venous blood. In the future, one part of the blood enters the right ventricle, the other through interatrial communication in the left atrium and the systemic circulation.
In this case, the anomalous drainage of the pulmonary veins is compatible with life only if there is a message between the two circles of blood circulation, the role of which is performed by the DMP or an open oval window. Hemodynamic disturbances in total abnormal drainage of the pulmonary veins are accompanied by hyperkinetic overload of the right heart, pulmonary hypertension and hypoxemia.
With a partial form of abnormal drainage of the pulmonary veins, hemodynamic disturbances are similar to those with interatrial defects. The decisive role among them belongs to the pathological arterio-venous discharge of blood, which leads to an increase in the volume of blood in the pulmonary circulation.
Symptoms of abnormal pulmonary vein drainage
The clinical manifestations of abnormal drainage of the pulmonary veins are based on anatomical and hemodynamic features: the level of general pulmonary resistance, the degree of obstruction of venous return, the size of atrial communication, the functioning of the right ventricular myocardium.
In the absence of a defect in the interatrial septum or its extremely small size, the defect is incompatible with life – in this case, only emergency endovascular balloon atrioseptostomy according to Rashkind allows saving the child.
In children with abnormal drainage of pulmonary veins, frequent repeated pneumonia and acute respiratory viral infections, low weight gain, shortness of breath, mild cyanosis, cough, fatigue, physical retardation, pain in the heart, and tachycardia are noted. In severe pulmonary hypertension, pronounced cyanosis, heart hump and heart failure develop already in early childhood.
Diagnosis of abnormal pulmonary vein drainage
The auscultatory picture of the abnormal drainage of the pulmonary veins is reminiscent of DMPP and is characterized by a non-coarse systolic noise in the projection of the pulmonary artery, splitting II tone. ECG data indicate overloading of the right sections, incomplete blockade of the right bundle of His; EOS is rejected to the right. Phonocardiography corresponds to all signs of DMPP.
When analyzing the results of chest radiography, attention is drawn to the expansion of the borders of the heart to the right, the bulging of the pulmonary artery, and the strengthening of the pulmonary pattern. A reliable sign of abnormal drainage of the pulmonary veins into the inferior vena cava is the symptom of the “Turkish saber”.
According to EchoCG, the mouth of the pulmonary veins is not detected in the left atrium; dilatation of the right ventricle, reduced size of the left heart and other indirect signs of abnormal drainage of the pulmonary veins are detected. Older children and adults undergo transesophageal echocardiography.
When sounding the cavities of the heart, a catheter from the right atrium or vena cava is carried into the pulmonary vein. At this stage of diagnosis it is possible to establish the localization of the confluence and the number of abnormally draining pulmonary veins. The right atriography, ventriculography, angiopulmonography, phlebography of VPW allow tracing the movement of contrast through the pulmonary circulation into the right atrium or vena cava.
In patients with abnormal pulmonary vein drainage, in differential-diagnostic terms, it is necessary to exclude atresia of the mitral or aortic valve, mitral stenosis, isolated DMPP, three-atrial heart, pulmonary vein stenosis, transposition of the great arteries, lymphangiectasia.
Prediction of anomalous pulmonary vein drainage
The natural course of total abnormal drainage of pulmonary veins is unfavorable: 80% of children die in the first year of life. Patients with partial pulmonary vein drainage can live up to 20-30 years. Death of patients is associated with severe heart failure or lung infections.
The results of surgical correction of abnormal pulmonary vein drainage are satisfactory, but among newborns, intra- and postoperative mortality remains high.