pediatric right ventricular double outlet
Introduction
Introduction to children's right ventricular double exit The double outlet of the right ventricle (doubleoutletrightventricle) refers to the fact that when the two large blood vessels are completely or nearly completely from the right ventricle, the anatomical diagnostic criteria have been re-evaluated with the development of the right ventricular double-extract surgical technique. For clinical and practical reasons, the clinical "90% principle" is used instead of the "50% principle." However, since it is easier to accurately determine the interconnection relationship between the aortic valve and the lower ventricular septum in the pathological anatomy, the diagnostic criterion is that when more than half of the roots of the two aortic roots are connected to the same ventricle, the diagnosis is right. Double exit. Thus, the right ventricular dual outlet can be associated with a biventricular, a single ventricle, or any large vessel and any type of atrioventricular connection. basic knowledge The proportion of illness: 0.002% Susceptible people: children Mode of infection: non-infectious Complications: atrial septal defect, patent ductus arteriosus, pulmonary hypertension, heart failure
Cause
Pediatric right ventricular double exit cause
Causes:
Due to the incomplete rotation of the conus arteries during embryonic development, the deviation from the left and right ventricles is different. The conus is formed during the development of palpitations in the embryonic development, and the right dorsolateral and left ventral ridges are merged and separated into Two cones on the anterior lateral and posterolateral sides connect the primordial tract of the right ventricle, and the posterior medial cone merges into the left ventricle to form the outflow tract. The formation of the right ventricle is related to the abnormal rotation and absorption of the cone. The aorta and The relationship between the pulmonary arteries and the relationship between the semilunar valves depends on the conical spacing and the development of the arterial trunk.
Pathogenesis:
1. Pathological anatomy: the right ventricle double outlet can occur in the atrial position of normal, anti-position or symmetrical position. In the case of surgery, 86% of the atrioventricular connections are consistent, 11% are inconsistent, and the right ventricle double outlet is mainly a cone. The part (funnel) is deformed, and the funnel (outflow channel) is completely above the anatomical right ventricle, not the outflow part of the interventricular septum, because the outflow tract is attached to the anterior or posterior branch of the septum trabecula The positional relationship between the funnels is different, the outflow channel spacing is attached to the anterior branch of the trabecular ligule, and the funnel is in the anteroposterior relationship, including the right front and the left rear; front, front and back; left front, right rear, The outflow tract interval is attached to the posterior branch of the trabecular trabeculae, or directly in the ventriculoinfundibular fold, and the funnel is in a juxtaposed relationship (Fig. 1). Most of the (70%) right ventricle double outlets have a funnel. The aorta originated from the funnel located in the right posterior part of the pulmonary artery. In the data of the de la Cruz group, 54% of the anterior and posterior funnels were associated with normal aorta, 37% of the aorta was juxtaposed to the right, and the aorta was anterior. 9% of the aorta When the relationship is normal, the outflow tract interval is perpendicular to the ventricular septum. In the right ventricle double outlet, the funnel is approximately 26% of the juxtaposition, and the pulmonary artery is almost always emitted from the inner funnel of the adjacent ventricular septum.
The aorta is parallel to the pulmonary artery, and the aorta is on the right side. Due to the size of the arterial trunk and the position of the heart, there are some changes in the position of the aorta and the position of the pulmonary artery. The interval of the outflow channel when the funnel is juxtaposed is perpendicular to the frontal plane. In the right ventricle double outlet, the ventricular septal defect is the first-class de novo anatomy of the left ventricle. Usually, the ventricular septal defect is unrestricted, that is, the defect diameter the aortic annulus diameter, the restrictive defect accounts for at least 10%, and there is no ventricular septal defect. Rarely, at this time often combined with mitral and left ventricular dysplasia, there is atrial septal defect as a left-to-right shunt channel, multiple ventricular septal defect accounted for about 17%, from the surgical point of view, usually according to the relationship between the defect and the aorta Dividing the ventricular septal defect into the subaortic defect, the subpulmonary defect, the doubly committed and the non-committed aortic defect, the so-called subaortic or pulmonary artery, does not mean that the semilunar valve is the interventricular septum. Part of the defect edge, the relationship between the defect and the aorta depends on the relationship between the aorta and the direction of the outflow channel spacing and small.
(1) Aortic lower ventricular septal defect: the most common type, accounting for about 50% of the right ventricle double-outlet surgery cases, the funnel is in the anterior-posterior relationship, and the defect is located between the anterior and posterior branches of the trabecular trabecular Most of them are perimembranous, the aortic valve leaf is the upper edge of the defect, the connection between the mitral annulus and the tricuspid annulus is the posterior inferior margin of the defect, and the other edges are the septal trabeculae, the funnel septum and the ventricular funnel pleats. A small number of defects are separated from the semilunar valve and the tricuspid valve by the ventricular phalanx muscle tissue. The margin of the defect is muscle. When the aorta is left, the ventricular septal defect is often subaortic defect, and the defect is more than the aorta. In the autopsy data, the right ventricle double outlet with aortic ventricular septal defect with 77% of the double cone was divided into 23%.
(2) Pulmonary ventricular septal defect: about 30% of the cases of right ventricle double exit surgery, most of the pulmonary ventricular septal defect without pulmonary stenosis, which is the Taussig-Bing type, the funnel is in a parallel relationship, the defect is located Between the anterior and posterior branches of the trabecular trabecular, if the lower cone of the pulmonary artery exists, the muscle tissue is separated between the defect and the pulmonary valve. The pulmonary valve and the mitral valve are directly continuous, and the pulmonary valve rides over the ventricular septal defect. The upper edge, the outflow channel spacing is toward the anterior wall of the right ventricle, separating the subaortic region from the ventricular septal defect. The outflow channel hypertrophy can cause subaortic stenosis. In the Taussig-Bing type, bilateral cone or individual The sub-arterial cone accounts for about 50%.
(3) lower ventricular septal defect: about 10%, the defect is located between the anterior and posterior branches of the trabecular ligament. Because the funnel is poorly developed or missing, the defect is directly under the aortic valve and pulmonary valve. The aortic valve and pulmonary valve become the upper edge of the defect. The aortic valve and the pulmonary valve are continuous. The trabecular trabeculae become the anterior, inferior and posterior margins of the defect, and both sides of the cone are absent.
(4) away from the aortic ventricular septal defect: 10% to 20%, the defect is not between the anterior and posterior branches of the trabecular ligament, away from the aortic valve and the pulmonary valve, located at the trabecular space, into the tract, or Perimembranous defects and extension to the inflow tract. Many distant aortic defects are seen in the right ventricle double outlet combined with complete atrioventricular septal defect. The spatial relationship between the aorta and the funnel is not consistent. In the right ventricle double outlet, there are two spatial relationships of the aorta. The type, spiral and parallel, mostly in a normal relationship. The aorta is in the right posterior aspect of the pulmonary trunk. The aorta spirals around the bottom of the heart. In this type, almost all ventricular septal defects are located under the aorta. When the aorta is in parallel with the pulmonary artery, the aorta can be juxtaposed on the right side of the pulmonary artery, or directly in front of the pulmonary artery, or in the right front of the pulmonary artery, or in the left front of the pulmonary artery. The aorta is parallel and in a juxtaposed relationship. The defect is often under the pulmonary artery, the aorta is less common on the left side, and the ventricular septal defect can be under the aorta. In fact, the anatomy of the ventricular septal defect Independent of the spatial relationship of the aorta, the right ventricle double outlet of the subaortic or lower ventricular septal defect, with pulmonary outflow obstruction accounted for 60% to 70%, and rare under the pulmonary artery or away from the aortic ventricular septal defect, more stenosis Seen in the funnel, there are also simple valve stenosis, or with valve, annulus and pulmonary dysplasia, aortic stenosis is rare, mainly occurs in the right ventricle double outlet of the pulmonary ventricular septal defect, aortic stenosis often due to the left ventricle (main Under the arteries) outflow dysplasia can also be caused by atrioventricular valve tissue or hypertrophic muscle bundle. When the right ventricle double outlet is inconsistent with the atrioventricular connection, the atrial position is usually normal, and the aorta and pulmonary artery are from the left anatomical right ventricle. The aorta is located on the left side of the pulmonary artery, juxtaposed or left front, and the ventricular septal defect is under the aorta or under the pulmonary artery. Neufeld et al. first proposed a relationship between the ventricular septal defect and the supraorbital sac and aorta, with or without pulmonary stenosis. Export classification method, in 1972, Lev et al. divided the right ventricle double outlet into the aortic lower chamber according to the relationship between the ventricular septal defect and the aorta. Septal defect type, pulmonary ventricular septal defect type, double arterial ventricular septal defect type and away from aortic ventricular septal defect type, this classification is widely used, but there are also deficiencies, recently, in the international congenital heart disease naming and database The right ventricle double outlets in the project are classified as:
1-ventricular septal defect (subaortic defect, double arterial defect).
2 Faro quadruple syndrome type.
3 large arterial translocation type (lower pulmonary artery with or without pulmonary stenosis).
4 away from the aortic ventricular septal defect type (based on or not complete atrioventricular septal defect, with or without pulmonary stenosis divided into 4 subtypes).
5 chamber septum complete type, combined with other cardiac malformations with atrioventricular valve (stenosis, atresia, riding, etc.), patent ductus arteriosus, ventricular dysplasia, aortic stenosis, aortic discontinuity, coronary sinus septal defect, pulmonary vein connection abnormalities, Juxtaposition of the atrial appendage, atrial septal defect and right heart.
2. Pathophysiology: Hemodynamics of the right ventricle double outlet and the size of the ventricular septal defect and its relationship with the aorta, combined with malformation, can be similar to ventricular septal defect with pulmonary hypertension, tetralogy of Fallot and complete aorta In the transposition, when the left ventricular blood is divided by the ventricular septal defect, the left ventricle and the right ventricle are equal. When the pulmonary outflow tract and the aortic outflow tract are not narrow, the pulmonary artery pressure is similar to the aortic pressure, and the systemic blood oxygen saturation depends on the circulation. In pulmonary blood flow, different oxygen saturation blood mixing and blood flow in the right ventricle, pulmonary blood flow is affected by pulmonary stenosis and pulmonary vascular obstruction, pulmonary artery oximetry is higher than pulmonary ventricular septal defect Aortic blood, with or without pulmonary stenosis or pulmonary vascular obstruction, with aortic ventricular septal defect, pulmonary oxygen saturation is still higher than aortic blood still accounts for 40%, right ventricular double outlet without pulmonary stenosis, Pulmonary hypertension and pulmonary vascular disease occur earlier.
Prevention
Pediatric right ventricular double exit prevention
Ask family history to understand the genetic situation, investigate the impact of environmental factors to explore the cause of congenital heart disease, Shaw through the investigation of the address to understand the environmental teratogenic factors that the pregnant mother may be exposed, the address of the mother's production is sometimes used to represent The address of the early pregnancy was estimated by environmental factors. The authors investigated the address of the mother at the time of pregnancy and birth. About 24.8% of the mothers moved between the beginning of pregnancy and production, so observing the production address may reduce congenital malformation and the mother's exposure to the environment. The positive result of the association should be investigated in the environment of the address at the time of pregnancy. Schwanitz advocated that the detection of cardiac malformation before birth can be used as an indication for chromosomal examination. The authors mentioned that 588 fetuses were diagnosed with growth retardation and/or congenital malformation before birth. A chromosome examination was performed, and 116 (19.7%) of these cases were confirmed to have chromosomal abnormalities. Among these malformed fetuses diagnosed before birth, 102 (17.3%) of the fetuses with cardiac malformations, therefore, cardiac malformations For the most common malformations, 41 fetuses (40.2%) have chromosomes in the fetus that was diagnosed with a cardiac malformation before birth. Frequently (compared with 18 and 21 trisomy) syndrome, in addition to monitoring the fetus, the mother's disease should also be monitored, Breton reported that the mother has phenylketonuria, phenylamino in plasma during pregnancy Propionic acid continues to increase, and its children have a heart malformation.
Breton reported that a child's coronary artery abnormalities originated in the right pulmonary artery, ventricular septal defect, fetal growth retardation and facial deformity. The parental plasma of phenylalanine increased continuously during pregnancy, and the cardiac malformation was diagnosed 8 months after birth. Its developmental delay is due to maternal phenylketonuria, which can also cause ventricular septal defect and coronary artery malformation. The authors suggest that if the mother begins a dietary treatment before pregnancy, it may prevent fetal damage, so if If you have an in-depth understanding of the cause, you can monitor the mother's disease and fetal malformation in the pregnant mother and the fetus before pregnancy. If possible, try to prevent fetal congenital malformation, but from a genetic perspective. From the perspective of environmental damage, the cause of congenital heart disease is not fully understood, and most of them are powerless in prevention.
Complication
Pediatric right ventricular double outlet complications Complications, atrial septal defect, patent ductus arteriosus, pulmonary hypertension, heart failure
Combined malformation: the right ventricle double outlet with pulmonary stenosis is the most common, the sternal, apical and xiphoid lower section can be used to examine the location of pulmonary stenosis, combined with Doppler ultrasound to measure the blood flow velocity to estimate the degree of stenosis, combined with the aorta Stenosis and/or aortic coarctation account for about 20% of the right ventricle double outlet, more common in the right ventricular double outlet with pulmonary ventricular septal defect, sternal section, lower ventricular ventricle section and upper sternum section are often used for examination Aortic and aortic arch malformation, atrioventricular valve malformation, atrial septal defect, patent ductus arteriosus can be diagnosed by relevant ultrasound section examination, the disease itself can be complicated by repeated pulmonary infection, pulmonary hypertension, heart failure, hyperhemoglobinemia , embolization, etc.
Symptom
Pediatric right ventricular double exit symptoms Common symptoms Post-operative systolic murmur murmur fatigue edema ventricular septal defect clubbing (toe) phenomenon heart failure apical beat diffusion
Children may have symptoms of bruising, congestive heart failure, or no symptoms. The type of clinical manifestation and the time of onset of symptoms depend on the pathological type and the severity of the accompanying malformation. In the fourth type of right ventricular double exit, if There is a serious lack of blood supply to the lungs, which can be seen in the neonatal period. The other types of right ventricle double outlets have a good balance of lung circulation, and often appear cyanotic or hypoxic episodes after the neonatal period, accompanied by aortic lower chamber. The typical clinical manifestation of the right ventricular double outlet of the septal defect is congestive heart failure at the first month of life without cyanosis, similar to the clinical manifestations of simple ventricular septal defect. If heart failure occurs early after birth, it should be considered whether The right ventricular double outlet with edema and pulmonary ventricular septal defect often showed mild cyanosis during quiet, exacerbated cyanosis after crying, and no specific signs of right ventricular double exit.
1. Aortic ventricular septal defect with pulmonary stenosis: the clinical manifestations are similar to the tetralogy of Fallot. Different degrees of pulmonary stenosis may be accompanied by varying degrees of bruising, which may occur within 1 year after birth. When the stenosis is severe, Early in the morning, cyanosis, fatigue, post-exercise shortness of breath, phlegm and hyperhemoglobinemia, physical examination can be found with cyanosis and clubbing (toe), pulsatile dispersion in the anterior region, and 2 to 4 intercostal spaces on the left sternum. And the 4 to 5/6 grade jet systolic murmur, the high left side of the sternum can be tremor, the first heart sound is normal, the second heart sound is single, and sometimes the third heart sound is available in the apical area.
2. Pulmonary ventricular septal defect with or without pulmonary stenosis: clinical manifestations are similar to complete vascular translocation with ventricular septal defect, usually manifested in cyanosis and congestive heart failure in infancy, such as with pulmonary stenosis Cyanosis appears earlier but often has no heart failure. In the case of edema, infants can have heart failure early, cyanosis and femoral artery beats weakened or disappeared, and physical examination revealed typical cyanosis and clubbing (toe). Height, weight is significantly behind the same age, the anterior region of the anterior region and the apex of the pulsating dispersion, high-profile IR 2 ~ 3 / 6 systolic murmur in the left side of the sternum, when accompanied by pulmonary stenosis is available 3 ~ 4 The loud systolic murmur, the second heart sound is usually loud and single, and the increase in pulmonary blood flow can smell the rolling diastolic murmur at the apex.
3. Aortic ventricular septal defect without pulmonary stenosis: clinical manifestations and large ventricular septal defect with pulmonary hypertension, usually bruising slightly but acute and acute congestive heart failure, repeated upper respiratory tract infection, left sternal can And 3 to 4/6 grades of full systolic murmur with tremor, apical area with diastolic murmur and third heart sound.
4. Aortic ventricular septal defect with pulmonary vascular obstructive disease: When the above group type is accompanied by organic pulmonary hypertension, pulmonary blood flow is reduced at this time, heart failure and repeated respiratory infections are rare, and cyanosis and clubbing may appear. (toe), physical examination is often no murmur, the second heart sounds bright and single, and can also achieve diastolic murmur caused by pulmonary artery reflux.
Examine
Pediatric right ventricular double exit inspection
Peripheral blood may have increased red blood cells, increased hemoglobin concentration, and increased white blood cell count and neutrophils in the presence of pulmonary infection.
1. Electrocardiogram: often manifested as sinus rhythm, right axis deviation and different degrees of right ventricular hypertrophy, QRS wave in the right chest lead often shows qR type, left ventricle often does not enlarge, if there is obvious left ventricle It is suggested that it is possible to incorporate a restrictive ventricular septal defect.
2. Chest X-ray: no characteristic changes, heart size and pulmonary blood depends on the hemodynamic state at that time, can be a small heart, lung blood reduction, can also be expressed as a large heart, lung blood increased significantly.
3. Echocardiography: Sexual sacral scan is very useful for the diagnosis of right ventricular double outlet. The diagnostic criteria are that all or most of the two large vessels are from the right ventricle. The double cone is common but not a necessary condition for diagnosis. The axial and short axes can detect the relationship between large blood vessels and the conus of the arteries. Because the anatomical types of the right ventricle double outlets vary greatly and are accompanied by various deformities, a comprehensive sequential segmentation diagnosis must be performed.
4. Cardiac catheterization: Before extracardiac surgery, it is usually confirmed by cardiac catheterization and angiography, echocardiographic diagnosis, and detailed hemodynamic information, the hemodynamic performance can be similar to the left to right of the large flow. Diversion, right ventricular single ventricle, tetralogy of Fallot, complete vascular transposition and pulmonary stenosis, information obtained by echocardiography can be used to select appropriate transillumination sites to clarify the origin of large vessels and ventricular septal defects position.
5. CT and MRI: CT and MRI examinations are helpful for the diagnosis of right ventricle double exit. The MRI spin echo T1W image can show the size of the left and right ventricles and the size of the ventricular septal defect. The MRI spin echo is observed layer by layer. The T1W transverse image is also helpful for determining whether the ventricular septal defect is located under the aorta or under the pulmonary artery. Contrast-enhanced magnetic resonance angiography and multi-slice spiral CT may have pulmonary stenosis in the right ventricle double outlet, upper left. Vena cava, venous drainage of the pulmonary veins, dysplasia of the aortic arch, etc., which have an effect on the surgery, can be well displayed.
6. Cardiovascular angiography: Right ventricle double outlet angiography requires right ventricular angiography and left ventricular angiography. Right ventricular angiography catheter can be retrogradely intubated from the aorta using a right heart catheter such as NIH. The right ventricle is better, the contrast agent is injected as quickly as possible, the left position and the sitting position are selected for the projection position, the catheter selection for left ventricular angiography, the contrast injection is the same as the right ventricle, and the projection position is the long axis oblique. Position, some patients need to add ascending aorta.
Cardiovascular angiography should pay attention to the location of the aorta and pulmonary artery, the development of the left ventricle, the location of the ventricular septal defect, the size, the relationship with the large blood vessels, the presence or absence of a cone between the mitral valve and the aorta, the development of the pulmonary artery, coronary artery The beginning and the direction, the development of the aortic arch and the connection of the atrioventricular, etc., usually the aorta and pulmonary artery originate from the right ventricle, or most of the origin from the right ventricle, under the large blood vessels have a cone, the location of the ventricular septal defect is Located under the aorta or under the pulmonary artery is one of the difficulties in the diagnosis of right ventricle double outlet angiography. Observing the positional relationship between the aorta and the pulmonary artery is helpful for diagnosis. When the X-ray and the interventricular septum are tangential, If the aorta and pulmonary artery overlap each other, the aortic ventricular septal defect, if the aorta and pulmonary artery are separated from each other, is the pulmonary ventricular septal defect, usually in the long-axis oblique left ventricular angiography, the X-ray and the interventricular septum are tangential The left and right ventricles are well separated and are in a anterior-posterior relationship. At this time, if the aorta and the pulmonary artery overlap each other, the lateral relationship is active. Lower ventricular septal defect, at this time, if the aorta and pulmonary artery are well separated, the anterior-posterior relationship is the pulmonary ventricular septal defect. The precautions for cardiovascular angiography are also related to the pathological type. The aortic ventricular septal defect is not associated with pulmonary stenosis. The right ventricle double outlet, the precautions are similar to the large ventricular septal defect, the right ventricle double outlet of the aortic ventricular septal defect with pulmonary stenosis, the precautions are similar to the tetralogy of Fallot, pay attention to the peripheral pulmonary artery The stenosis, the direction of the coronary artery, the right ventricular double outlet of the pulmonary ventricular septal defect without pulmonary stenosis, and the complete transposition of the great arteries, should pay attention to the development of the coronary artery and aortic arch.
Diagnosis
Diagnosis of differential diagnosis of pediatric right ventricular double outlet
Mainly rely on echocardiography, cardiac catheterization and cardiovascular angiography.
Due to various clinical manifestations, it should be differentiated from giant ventricular septal defect and tetralogy of Fallot, relying on imaging examination for identification.
