Total anomalous pulmonary venous drainage

Veins that carry oxygenated blood from the lungs to the heart.

In the pulmonary veins

are veins that transfer oxygenated blood from the lungs to the heart.
The largest pulmonary veins are the four main pulmonary veins
, two from each lung, which drain into the left atrium of the heart. The pulmonary veins are part of the pulmonary circulation.

Structure [edit]

Two main pulmonary veins

emerge from each hilum of the lung, receiving blood from three or four bronchial veins each and draining into the left atrium. The inferior and superior main veins drain each lung, so there are four main veins in total. [1]

At the root of the lung, the right superior pulmonary vein lies in front of and slightly below the pulmonary artery; the lower one is located at the very bottom of the hilum of the lung. Behind the pulmonary artery is the bronchus. [2] The right main pulmonary veins (containing oxygenated blood) pass behind the right atrium and superior vena cava; on the left in front of the descending thoracic aorta.

Option [edit]

Sometimes the three lobar veins on the right side remain separate, and often the two left lobar veins end in a common opening into the left atrium. Consequently, the number of pulmonary veins opening into the left atrium may vary from three to five in a healthy population.

The two left lobar veins may be combined into a single pulmonary vein in approximately 25% of people; the two right veins can be united by approximately 3%. [2]

Medical Internet conferences

The length of the veins of the 2nd order (Table 1) on the right ranges from 9.5 mm at the vein of the lower zone to 14.6 mm at the vein of the posterior zone, on the left - from 10.8 mm at the vein of the posterior zone to 14.2 mm at the vein anterior zone. There is a statistically significant increase in the length of the right vein of the posterior zone compared to the left. The least variable in length among the veins of the 2nd order, both on the right and on the left, is the vein of the posterior zone, the most variable is the vein of the upper zone. The left veins are less variable than the right.

The vein of the posterior zone has the smallest internal diameter among the veins of the 2nd order on the right (Table 2), the vein of the upper zone has the largest (5.1 mm), the minimum internal diameter on the left is the vein of the anterior zone and the vein of the posterior zone (3.2 mm), maximum – at the vein of the upper zone (5.6 mm). The diameter of all left veins of the 2nd order, with the exception of the vein of the anterior zone, exceeds the diameter of the corresponding right veins. There is a statistically significant increase in the diameter of the left vein of the posterior zone compared to the right.

In the right lung, the most variable vein is the posterior zone vein, the least variable is the inferior zone vein. On the left and right, the most variable is the vein of the anterior zone, the less variable is the vein of the lower zone.

The cross-sectional area of ​​the lumen of the veins of the 2nd order (Table 3) ranges on the right from 5.7 mm2 for the vein of the posterior zone to 22.4 mm2 for the vein of the upper zone, on the left - from 8.8 mm2 for the vein of the anterior zone to 28.0 mm2 at the vein of the upper zone.

There is a statistically significant increase in the cross-sectional area of ​​the left zone of the posterior vein compared to the right. Both on the right and on the left, the vein of the lower zone is the least variable in terms of the cross-sectional area of ​​the lumen; the most variable on the right and left is the vein of the anterior zone.

The relative cross-section of the lumen of the 2nd order veins on the right ranges from 11.4% for the vein of the posterior zone to 38.2% for the vein of the anterior zone, on the left - from 13.7% for the vein of the posterior zone to 40.8% for the vein of the upper zone . The total cross-section of the lumen of the 2nd order veins is 56.4 mm2 on the right, 63.8 mm2 on the left.

Assessment of dissymmetry of second-order pulmonary vein parameters was carried out on the basis of dissymmetry indicators. These indicators were calculated using the method proposed by V.S. Speransky (1963), by finding the ratio of the value of a feature (length, diameter of a vessel) on the right to the value of the same feature on the left. Indicators of dissymmetry and the formation of second-order pulmonary veins were determined by the ratio of the number of dissymmetrical features to the total number of studied features. The percentage frequency of symmetrical and asymmetrical forms of branching of second-order veins was determined. studied (length, diameter, PSA) on the right to the value of this studied on the left on each preparation, after which the arithmetic mean value of the dissymmetry index was determined. Data on the percentage of symmetrical, asymmetrical, right-sided, left-sided forms of length, diameter, cross-sectional area of ​​the lumen of the 2nd order pulmonary veins are presented in Tables 4 and 5. Symmetrical formation of the vein of the upper zone was observed in 20 of 43 preparations, dissymmetrical - in 23 preparations ; the fusion of the anterior zone vein was symmetrical in 37 out of 41 cases, asymmetrical in 4 cases; the vein of the posterior zone was formed symmetrically in all 45 preparations; the vein of the lower zone had a symmetrical fusion in 23 out of 45 specimens, and a dissymmetrical fusion in 22 specimens.

Indicators of dissymmetry in the formation of second-order veins in people of mature age are 0.33. A higher frequency of dissymmetrical variants of the formation of veins in the upper and lower zones and a predominance of variants of the formation of veins in the anterior and posterior zones, symmetrical in the number of roots, were noted.

Links[edit]

This article incorporates open access text from page 642 of the 20th edition

"Grey's Anatomy"
(1918).

1. Drake, Richard L.; Fogle, Wayne; Tibbits, Adam W. M. Mitchell; illustrations by Richard; Richardson, Paul (2005). Gray's Anatomy for Students
   (Pbk. Ed.). Philadelphia: Elsevier/Churchill Livingston. ISBN 978-0-443-06612-2.
2. ^ab Skandalakis, Editor-in-Chief John E. (2004). "Chapter 7. Pericardium, heart and great vessels of the chest." Skandalakis' surgical anatomy: embryological and anatomical foundations of modern surgery
   . Athens, Greece: PMP. page section “Pulmonary veins”. ISBN 9603990744.CS1 maint: additional text: authors list (link)

Currently, the etiological factors of many genetic syndromes and familial congenital heart defects (CHDs) have been identified, but the genetic basis of most “sporadic” CHDs still remains unknown. The leading causes of the development of congenital heart disease are presented in Fig. 1.

Rice. 1. Etiology of congenital heart disease [3].

Many genes associated with heart development have been identified. It has been established that a number of individual congenital heart diseases and genetic syndromes are associated with mutations in various single genes [1].

Many genes encoded by transcription factors or signaling molecules are currently associated with CHD in humans. Transcription factors are proteins that contain DNA-binding domains and play a fundamental regulatory role in controlling gene expression. Signaling molecules are proteins that enable cells to respond to their environment and are thus involved in the regulation of many important biological functions.

The phenotypes of congenital heart disease range from small septal defects that may remain undetected throughout life to hemodynamically significant abnormalities that manifest clinical symptoms. These include anomalies ranging from persistent fetal circulation (eg, patent ductus arteriosus) to complex defects such as transposition of the great vessels, single ventricle, hypoplastic left heart syndrome, and other heterotaxy variants. In accordance with the pathogenetic classification of congenital malformations of the cardiovascular system, there are 6 causal mechanisms: anomalies in the migration of ectomesenchymal tissue (anomalies of the aortic arch), defects in intracardiac blood flow (septal defects and obstructive defects of the left or right heart), anomalies associated with cell death (septal valve defects and anomalies), extracellular matrix abnormalities (atrioventricular canal defects), abnormal growth (partial or complete pulmonary venous return malformation and triatrial heart), and malposition and torsion, which includes left-right asymmetry [2].

For example, homeobox-containing proteins encoded by the NKX-2.5 group of genes play an important role in regulating the tissue-specific expression of genes required for tissue differentiation, as well as for determining temporal and spatial patterns of development. Research has recently shown that non-syndromic congenital heart disease may be the result of a single gene defect. Based on this, we can conclude that the predisposition to congenital heart disease is the result of single nucleotide polymorphisms or mutations of key genes, which, when interacting with environmental factors, disrupt the normal morphogenesis of the heart, which leads to the development of congenital cardiac anomalies (see table)

Genetic causes of congenital heart defects [3] [3].

Partial anomalous pulmonary venous drainage (PAPVD) is a congenital heart defect characterized by one or more (but not all) pulmonary veins draining into the right atrium, or into the vena cava, or into their main branches [4].

There are four anatomical forms of PAD, which are based on the location of the confluence of the pulmonary veins: supracardial, intracardial, infracardial and mixed. Anomalous drainage of the right pulmonary veins occurs 2 times more often than the left ones. The right pulmonary veins can drain into the superior vena cava, which is often combined with a defect of the venous sinus (Fig. 2, a),

Rice. 2. Scheme of options for CHADLV. a — drainage of the right pulmonary veins into the SVC with a venous sinus defect; b - in the IVC; c — confluence of the left pulmonary veins into the innominate vein; d - coronary sinus. a — right pulmonary veins drainage into SVC with sinus venosus ASD; b —into IVC; c — connection of left pulmonary veins with innominate vein; d - coronary sinus. or flow into the inferior vena cava (see Fig. 2, b) with an intact atrial septum and bronchopulmonary sequestration. The left pulmonary veins often drain into the innominate vein (see Fig. 2, c) or into the coronary sinus (see Fig. 2, d). Atrial septal defect is usually accompanied by abnormal drainage of the left pulmonary veins [5].

The defect was first described by Winslow in 1739. A pathological examination revealed abnormal drainage of the vein of the upper lobe of the right lung into the superior vena cava. Brody (1942) studied the anatomy and clinical picture of this defect most fully. R. Darling et al. systematized the anatomical variants (types) of the defect. [4] in 1957

The first successful operation to correct partial anomalous drainage using the closed “atrioseptopexy” method was performed by W. Neptune in 1953. In 1956, J. Kirklin et al. [4] reported 5 successful operations to correct the defect using the semi-open Gross method.

The specific causes of PAD are unknown. They may be associated with chromosomal abnormalities detected by karyotyping in more than 1/3 of patients with congenital heart disease. Most often this is trisomy on the 21st, 18th and 13th pairs of chromosomes. In addition to Down's disease, there are about 20 hereditary syndromes, in most cases accompanied by various congenital heart defects. In total, syndromic pathology is found in 6-36% of patients. The monogenic nature of congenital heart disease has been proven in 8% of cases; about 90% are inherited multifactorially, that is, they are the result of a combination of genetic predisposition and exposure to environmental factors. The latter act as provoking agents, revealing hereditary predisposition when the threshold of their joint action is exceeded [6, 7].

According to various studies [8–10], the incidence of PADVC among all congenital heart defects ranges from 0.7 to 9.4%. Of all cases of anomalous pulmonary venous drainage, about 2/3 of them occur in PAD. More often the right pulmonary veins are involved in the process. The superior vena cava is the most common site of entry for anomalous right pulmonary veins (35–57% of all cases of PAPV). Less commonly, the pulmonary veins flow into the azygos vein; an extremely rare option is the flow of one or all pulmonary veins into the innominate or accessory left vein.

The second most common type is the intracardial type of right-sided PAD. Anomalous drainage of the left pulmonary veins is extremely rare, with the pulmonary veins draining into the coronary sinus or directly into the right atrium.

With the infracardial type of defect, the veins (usually the middle and lower lobes of the right lung) flow into the inferior vena cava (IVC) immediately below the diaphragm [11].

PADLV may also be part of more complex congenital heart disease. About 20% of patients with PAD have associated heart defects, such as tetralogy of Fallot, atrial septal defect (ASD) or ventricular septal defect (VSD), common ventricle, common atrium, transposition of the great vessels, and hypoplastic left heart syndrome [12]. However, most often PAD is found in combination with ASD (more than 50% of cases) [9].

Between the 4th and 5th weeks of embryogenesis, pulmonary veins begin to form in the dorsal mesocardium, emanating from the midpharyngeal endothelial stalk [13]. The formation of PAD occurs as a result of atresia of a large branch of the common pulmonary vein. Once the right or left part of the common pulmonary vein becomes atretic, the persistence of the pulmonary-systemic venous connection on this side creates the etiological basis for PADV [12].

Risk factors for the development of PAD are maternal age over 40 years, toxicosis and threat of miscarriage in the first trimester, a history of stillbirth, and the presence of children with congenital malformations in parents and close relatives [14].

It should be noted that in the closest relatives of a patient with cardiac anomalies, the incidence of congenital heart disease is 2-5 times higher [14]. However, in the literature available to us, the familial form of PADLV has not been described.

Hemodynamics and clinical signs of PAD are consistent with those of ASD. X-ray examination may reveal dilation of the shadow of the superior vena cava (SVC) and the root of the right lung with abnormal drainage into the SVC. When the pulmonary veins flow into the SVC in the anteroposterior projection, against the background of the lower lobe of the right lung, the shadow of an abnormally running vessel in the form of a “Turkish saber” is revealed (S. Dolter, 1949). An increase in the vascular bundle to the left allows one to suspect an anomalous flow of the left pulmonary veins into the left innominate vein [15].

Currently, echocardiography (EchoCG) is the main diagnostic method of research in patients with PAD, however, only computed tomography (CT) with intravenous contrast allows one to establish a final diagnosis, clarify the anatomy of the congenital defect and determine further surgical tactics [16, 17].

There are several described techniques for correcting partial right anomalous pulmonary venous drainage: simple tunnelization (switching the pulmonary veins into the left atrium with a patch), tunnelization with expansion of the SVC with a patch, tunnelization with excision of the SVC and its movement into the right atrium (usually into the atrial appendage) [18 ].

There are no differences in the results of the three techniques. The choice of surgical intervention technique depends on the type of abnormal drainage and the clinical picture of the defect [18].

We present a clinical observation of patient A

., 18 years old, admitted to the cardiac surgery department with a diagnosis of congenital heart disease, ASD. Partial anomalous drainage of the right superior pulmonary veins into the superior vena cava. Pulmonary hypertension stage I Circulatory failure degree IIa, functional class II.

At the time of examination, the patient complained of shortness of breath and weakness during moderate physical activity. From the anamnesis it is known that the diagnosis of ASD was established in November 2021 at the age of 17 years according to echocardiography. In January 2021, a multislice CT (SCT) of the heart with intravenous contrast was performed, revealing a secondary ASD without an upper edge, partial anomalous drainage of the right pulmonary veins into the SVC, and dilation of the right chambers of the heart.

According to the SCT data, three veins from the upper, middle and partially lower right pulmonary veins flow into the lower third of the SVC in a single collector (diameter 17 and 11 mm) from the middle lobe (Fig. 3, 4).

Rice. 3. Patient A., 18 years old. SCT with IV contrast. 1 - ASD. CT-scan. 1 - atrial septal defect.

Rice. 4. Patient A., 18 years old. SKT. The collector of the upper, middle and partially lower right pulmonary veins, flowing into the SVC (indicated by an arrow). CT-scan. Partial anomalous pulmonary venous return into SVC (arrow). The distance from the upper edge of the collector to the level of the entry of the SVC into the right atrium was 17 mm. Also, a vein from the middle lobe of the right lung with a diameter of 5.5 mm flowed into the ASD area. An ASD without an upper edge measuring 25×18 mm was determined. The right inferior pulmonary vein, as well as the left pulmonary veins, drain into the left atrium.

The patient's condition upon examination was moderate. Blood pressure 110/70 mm Hg, heart rate 70 beats/min. Heart sounds are clear and rhythmic. A systolic murmur is heard in the second intercostal space on the left. The ECG showed 1st degree atrioventricular block (PQ interval 0.22 s), as well as incomplete right bundle branch block.

According to echocardiography, there was an enlargement of the right heart, dyskinesia of the interventricular septum, and pulmonary hypertension up to 40 mm Hg. In the area of ​​the upper third of the MPP, a fault with a diameter of 12–13 mm was determined from left to right.

The patient admitted to our department was operated on. Intraoperatively: the heart is enlarged in size due to the right sections. A collector of three pulmonary veins from the upper and middle lobes of the right lung with a diameter of 4, 6 and 7 mm was visualized extrapericardially (Fig. 5),

Rice. 5. Intraoperative photo. The collector of the upper, middle and partially lower right pulmonary veins, flowing into the SVC (indicated by an arrow). Partial anomalous pulmonary venous return into SVC (arrow). flowing into the ERV at a distance of 17 mm from its mouth, the height of the collector is 14 mm. The vein from the lower lobe of the right lung flows into the left atrium. The left pulmonary veins also drain into the left atrium. During the revision of the MPP, a defect without an upper edge of 2.5×1.8 cm and an open oval window were noted. The lower edge of the defect is connected to the open oval window, forming an ASD of 3.5×2 cm (Fig. 6).

Rice. 6. Intraoperative photo. 1 - ASD without upper edge; 2 - open oval window. 1 — secundum atrial septal defect; 2 - primum atrial septal defect.

The defect was repaired with a tunnel-shaped patch made of xenopericardium (Fig. 7).

Rice. 7. Tunnel-shaped patch from the xenopericardium on the ASD with the relocation of the mouths of the right pulmonary veins to the left atrium. The MPP is sealed. IAS is sealed.

The postoperative period was uneventful and uneventful. The patient was discharged on the 8th day after surgery in satisfactory condition. Upon discharge, the ECG showed an inferior atrial, regular rhythm with a frequency of 75 beats/min, as well as incomplete blockade of the right bundle branch.

From the anamnesis it is known that the patient’s father, at the age of 15 years, was also diagnosed with PAD and ASD. He was operated on, and intraoperatively an anomalous drainage of the superior right pulmonary vein into the ostium of the SVC was discovered. The patient underwent ASD repair with relocation of the pulmonary vein from the upper lobe of the right lung to the left atrium.

In addition, the patient's cousin was operated on at the age of 8 months for congenital heart disease. A central atrial septal defect with a diameter of 15 mm and an anomalous drainage of the right superior pulmonary vein into the right atrium were identified; the defect was closed with a xenopericardial patch with relocation of the pulmonary vein orifice into the left atrium.

In our center, they underwent cardiac MRI to visualize the anatomical structure and monitor the long-term results of surgical treatment of patients (Fig. 8),

Rice. 8. Patient A. (father of the patient). MRI of the heart. The superior pulmonary veins flow into the left atrium at the mouth of the SVC (indicated by an arrow). MRI. Partial anomalous pulmonary venous return (arrow). According to the results of which, the collector of the right pulmonary veins flowing into the left atrium was visualized in the patient’s father. There was no evidence of ASD recanalization, other additional pathological discharges, or obstruction of blood flow through the pulmonary veins in both cases. A feature of these operations is the presence of an inferior atrial rhythm with an adequate frequency, which is associated with the placement of sutures in the projection of the sinus node.

Predisposition to congenital heart disease results from single nucleotide polymorphisms or mutations in key genes that, when interacting with environmental factors, disrupt normal cardiac morphogenesis, leading to the development of congenital cardiac anomalies. The specific causes of PAD are unknown. Deviations in embryogenesis and the presence of congenital heart disease in close relatives increase the likelihood of anomalies in the development of the heart. In the above clinical observation, the presence of PADLV was noted in the patient’s father and cousin. PAD is more common in combination with an ASD and is often represented by one or more abnormally draining right pulmonary veins. According to long-term results, surgical intervention in the form of tunnelization (moving the mouths of the pulmonary veins into the left atrium with a patch) is a reliable and effective method of treating PAD. In the available literature, we have not found a description of the familial form of PADLV.

The authors declare no conflict of interest.

The authors declare no conflicts of interest.

Information about authors

Ivanov A.S.

- Doctor of Medical Sciences, Prof.; https://orcid.org/0000-0001-9645-7192;

Glamazda S.V.

- Ph.D.; https://orcid.org/0000-0002-7623-2954;

Lugovsky M.K.

- Ph.D.; https://orcid.org/0000-0001-6461-7008, e-mail;

Lebedeva A.V.

- Ph.D.; https://orcid.org/0000-0001-7000-6254;

Govorova T.N.

— resident of the cardiac surgery department; https://orcid.org/0000-0001-6537-7173;

Satsyuk O.V.

- cardiovascular surgeon; https://orcid.org/0000-0001-8797-3283.

Ivanov A.S., Glamazda S.V., Lugovsky M.K., Lebedeva A.V., Abramova N.N., Govorova T.N., Satsyuk O.V. Familial form of partial anomalous pulmonary venous drainage. Cardiology and cardiovascular surgery

I. 2019;12(1):53-59. https://doi.org/10.17116/kardio20191201153