Congenital Anomalies of the Superior Vena Cava: Embryological Correlation, Imaging Perspectives, and Clinical Relevance.

There is a wide spectrum of congenital anomalies of the superior vena cava, which are more increasingly recognized in cross-sectional imaging. Although some of these anomalies are asymptomatic, others have important clinical and interventional implications. Imaging modalities such as computed tomography and magnetic resonance imaging play an important role in the accurate characterization of these anomalies, which is essential for mapping prior to surgeries or interventions. In this article, we review a wide range of anomalies of the superior vena cava, including the embryological basis, cross-sectional imaging findings, and clinical implications, particularly from an interventional radiology perspective. We also discuss the treatments and complications of these anomalies.

Evaluation of changes in Doppler ultrasonography indices and levels of maternal serum angiogenic factors throughout pregnancy in ewes.

We evaluated the changes in the pulsatility index (PI) and resistance index (RI) of fetal and maternal vessels and maternal serum angiogenic factors throughout pregnancy in 20 Kivircik ewes. They were examined for pregnancy detection on Day 30 after mating. The PI and RI during the pregnancies were followed using Doppler ultrasonography (USG) of the uterine artery, umbilical artery, fetal aorta, and fetal vena cava. Doppler USG was performed every 15 days beginning from the 40th day after mating. Blood samples were collected every 15 days starting from the day of mating. Nitric oxide (NO), vascular endothelial growth factor, basic fibroblast growth factor, and angiopoietin-1 and -2 levels were measured in maternal serum. A gradual decline was observed in the PI and RI of the umbilical artery beginning from Day 75 of pregnancy. Similarly, the RI of the uterine artery decreased on Day 135. Embryonic resorption was detected in two ewes with an increased PI and RI in the uterine artery. A significant and gradual decrease in the maternal serum vascular endothelial growth factor level was observed throughout pregnancy. The maternal serum NO level increased beginning from Day 135 of pregnancy. The results of this study illustrate the progressive changes in the Doppler USG findings of fetomaternal vessels and maternal serum angiogenic factors that occur throughout ewe pregnancy. The umbilical and uterine artery Doppler USG findings and maternal serum NO concentration may be important parameters for evaluation of the course of pregnancy in ewes. The results of this study should be compared with those of further studies that include compromised pregnancies and nonpregnant ewes.

[HISTOGENESIS AND PECULIARITIES OF STRUCTURAL ORGANIZATION OF THE CARDIAC MUSCLE TISSUE IN THE WALLS OF HUMAN CAVAL AND PULMONARY VEINS].

To study the structural organization and histogenesis of the cardiac muscle tissue in the walls of human caval and pulmonary veins, the heart was examined in 3 human embryos (at weeks 6-7 of development) and 20 fetuses (at weeks 9-10, 16, 19, 22 and 24 of development), as well as segments of caval and pulmonary veins of adult men and women (n = 50) located at various distances from the heart. The methods of light and electron microscopy were used in this work. To obtain the isolated cells from the walls of caval and pulmonary veins, the method of tissue alkaline dissociation was used. An immunohistochemical study with the monoclonal antibodies against cardiac troponin T was performed. It was found that the cardiomyocytes in humans were located in the middle and outer tunics of caval and pulmonary veins, where they formed thick layers. In the pulmonary veins of the adult humans, cardiac muscle fibers did not reach the intrapulmonary areas, in the inferior vena cava their layer did not extend beyond the pericardium, in the superior vena cava, its length was 2.5-3.0 cm. The formation of the pulmonary vein orifices occured by sequential inclusion of the wall of the common pulmonary vein, and later--of the right and left pulmonary veins into the wall of the left atrium. During the formation of the orifices of the caval veins, the gradual inclusion of the wall of the venous sinus in the wall of the right atrium was observed, resulting in caval veins opening directly into the cavity of the right atrium. The veins studied were referred to the veins of the muscular type with the strong development of muscular elements containing the myocardial component.

Study of the development of uteroplacental and fetal feline circulation by triplex Doppler.

The objective was to evaluate blood flow in fetal and maternal vessels by Triplex Doppler and its association with development of blood vessels during gestation in the domestic cat. Ten queens were examined weekly from 14 to 63 d after mating. Peak systolic velocity (PSV), end diastolic velocity (EDV), resistance index (RI) and pulsatility index (PI) of uteroplacental, aorta and umbilical fetal arteries and caudal vena cava of the fetus were evaluated. Throughout pregnancy, there was an increase in PSV and EDV in the aorta and umbilical arteries. In the caudal vena cava, there was an increase in PSV, whereas the EDV was constant, with a significant increase on Day 63. Peak systolic velocity and EDV of the uteroplacental artery reduced significantly on Day 63. Resistance index of the umbilical artery progressively decreased. In the aorta, this reduction was detected only on Day 42, with no defined pattern in the caudal vena cava and uteroplacental artery. Pulsatility index of the aorta varied. Although pulsatility increased in the caudal vena cava on Day 35 and remained elevated, pulsatility was significantly reduced in the umbilical artery by Day 63. The pulsatility index of the uteroplacental artery was constant (increased only on Day 63). Triplex Doppler evaluation could be a useful adjunct for prenatal care of pregnant queens, including assessment of vascular gestational development and prediction of gestational age.

Development of the pulmonary vein and the systemic venous sinus: an interactive 3D overview.

Knowledge of the normal formation of the heart is crucial for the understanding of cardiac pathologies and congenital malformations. The understanding of early cardiac development, however, is complicated because it is inseparably associated with other developmental processes such as embryonic folding, formation of the coelomic cavity, and vascular development. Because of this, it is necessary to integrate morphological and experimental analyses. Morphological insights, however, are limited by the difficulty in communication of complex 3D-processes. Most controversies, in consequence, result from differences in interpretation, rather than observation. An example of such a continuing debate is the development of the pulmonary vein and the systemic venous sinus, or "sinus venosus". To facilitate understanding, we present a 3D study of the developing venous pole in the chicken embryo, showing our results in a novel interactive fashion, which permits the reader to form an independent opinion. We clarify how the pulmonary vein separates from a greater vascular plexus within the splanchnic mesoderm. The systemic venous sinus, in contrast, develops at the junction between the splanchnic and somatic mesoderm. We discuss our model with respect to normal formation of the heart, congenital cardiac malformations, and the phylogeny of the venous tributaries.

Magnetic resonance angiography of fetal vessels: feasibility study in the sheep fetus.

PURPOSE: The aim of this study was to perform fetal magnetic resonance angiography (MRA) in utero in a sheep model. MATERIAL AND METHODS: Images of the great vessels, the heart, and the tracheal tree were performed on four pregnant ewes with a 1.5-T scanner (Philips Medical Systems, Best, The Netherlands). MRA was achieved in utero using a nontriggered free-breathing three-dimensional balanced fast field echo (FFE) technique. All obtained MRA images were evaluated in consensus on a three-point scale by two radiologists with 9 and 4 years of experience in fetal MRI, respectively. RESULTS: The fetal heart frequencies were between 130 and 160 bpm. The aorta from the aortic bulb to the bifurcation as well as some of the main aortic branches could be depicted. The pulmonary trunk and arteries, the superior and inferior caval veins, and the subsegmental branches of the trachea could also be visualized. CONCLUSION: The nontriggered MRA of the fetal great vessels with images of the tracheal tree allowed an excellent evaluation of anatomical structures.

Doppler evaluation of maternal and fetal vessels during normal gestation in rabbits.

The aim of this work was to evaluate the hemodynamic changes in the utero-placental arterial vessels in rabbits (Orictolagus cuniculus) throughout pregnancy as well as those in the umbilical cord, aorta, and caudal vena cava of fetuses to establish their normal reference ranges for systolic peak velocity (SPV), end diastolic velocity (EDV), pulsatility index (PI), and resistance index (RI). The blood flow waveforms were monitored every 4 d in 10 rabbits from Day 10 of pregnancy onward by means of color and pulsed wave Doppler ultrasonography using a 5.5-7.5 MHz microconvex transabdominal probe. The utero-placental blood flow was characterized by steep increases and decrease in the SPV with a slow diastolic wave and relatively high EDV, whereas that of the umbilical artery was discontinuous until Day 22 of pregnancy, when a diastolic waveform was also detectable. From Day 10 to 22 of pregnancy, the fetal aorta blood flow was discontinuous, but thereafter a diastolic peak was measurable. The blood flow of the fetal caudal vena cava was characterized by a systolic peak followed by a small diastolic peak. Throughout the gestation, the SPV and the EDV of maternal and fetal vessels increased (alpha<0.05), whereas the PI and the RI decreased (alpha<0.05), except for the utero-placental vessels. This work confirms that the rabbit could also be a valid experimental animal model to study, by Doppler ultrasonography, functional hemodynamic changes of the fetuses and placenta vessels in both normal and pathophysiologic conditions.

Venas superficiales de la fosa cubital: aspectos anátomo-clínicos y antropológicos / Superficial veins of the cubital fossa: anatomo-clinic and anthropologic aspects

Es bastante frecuente el acceso a las venas superficiales de la fosa cubital, siendo uno de los sitios más utilizados para punción venosa. Aunque es un procedimiento simple, es invasivo y a veces doloroso. La disposición de las venas superficiales de la región cubital ha sido descrita por numerosos autores y en diversos grupos étnicos, describiéndose variaciones y diversas padronizaciones. Las venas superficiales de la fosa cubital se han descrito formando una M, N, Y y W. Numerosos estudios, en distintas razas y grupos étnicos han demostrado similitudes y diferencias en la disposición de las venas superficiales de la fosa cubital. En 1908 Berry & Newton determinaron que en el 83% de los hombres británicos la vena cefálica del antebrazo (VCA) y la vena basílica del antebrazo (VB A) eran conectadas por la vena mediana del codo (VMCo). Okamoto (1922) en hombres japoneses, determinó 3 Tipos de padrones venosos: Tipo I donde la VCA origina la VMCo, no existe la vena cefálica accesoria del antebrazo (VCAA), y la VCA no se duplica; Tipo II, caracterizado por la duplicación de la VCA y un Tipo III, que incluye la VCAA que drena en la VCA. En hombres blancos y negros Charles (1932) señaló que la distribución más frecuente (cerca de 70% de los casos), era aquella donde la VCA y la VB A eran conectadas por la VMCo. Soller et al. (1962, 1964) en africanos de África Occidental, distinguieron tres tipos de formaciones venosas. Grupo I. Disposición clásica, tipos en M o aparentes (38,1%). Grupos II y III descritas como disposiciones de tipo embrionario constituyen el 62% de los casos. Halim & Abdi (1974) en hindúes, observaron tres tipos: 1) Tipo I. La VCA y la VBA son conectadas por la VMCo; Tipo II. La VCA drena en la VBA; la vena mediana del antebrazo (VMA) drena en la VCA. Tipo III. No existe comunicación entre la VCA y la VBA en la fosa cubital y la subdividen en Tipos IIIA y III B. Wasfi et al. (1986) describieron ...

Access of the cubital fossa to the superficial veins is very frequent, this being one of the most frequent vein puncture sites. Although it is a simple procedure, it is invasive and at times painful. The disposition of the superficial veins of the cubital area has been described by numerous authors and in diverse ethnic groups, describing many variations and various patterning. The superficial veins of the cubital fossa have been independently described, forming an M, N, Y or W. Numerous studies in different races and ethnic groups have demonstrated similarities and differences in the disposition of the superficial veins of the cubital fossa. In 1908 Berry & Newton determined that in 83% of British men the cephalic vein of the forearm (CVF) and the basilic vein of the forearm (BVF) were connected by the median cubital vein (MCV) Okamoto (1922) in Japanese men, determined 3 types of venous patterns. Type I where the CVF originates the MCV, the accessory cephalic vein (ACV) does not exist, and the (CVF) does not duplicate; Type II is characterized by the duplication of the CVF and a Type III, that includes the ACV which drains in the CVF. In white and black men Charles (1932) indicated that the most frequent distribution (nearly 70% of the cases), was that where the CVF and the BFV were connected by the MCV. Soller et al. (1962, 1964) in Africans from West Africa, distinguished three types of venous formations. Group I classic dispositions, types in M or apparent (38.1%) Groups II and III described as dispositions of the embryological type constitute 62% of the cases. Halim & Abdi (1974) observed 3 types in Hindus types: 1) Type I. The CVF and the BVF are connected by the MCV; Type II. The CVF drains in the BVF: the median vein of the forearm (MVF) drains in the CVF. Type III. There is no communication between the CVF and the BFV in the cubital fossa and it is subdivided in Types III A and III B. Wasfi et al. (1986) described ...

[Histogenesis and structural organization of the walls of rat venae cavae and pulmonary veins]. / Gistogenez i strukturnaia organizatsiia stenki polykh i legochnykh ven krysy.

Using light and electron microscopic methods, the histogenesis and structural organization of the walls of rat venae cavae and pulmonary veins were studied in prenatal and postnatal periods of development. The special attention was paid to the appearance of the striated myocytes in the walls of these vessels during the process of ontogenesis. The time of initial divergent development of myoblastic differon was established, the stages of differentiation of striated myoblasts and the peculiarities of intercellular junctions were characterized, as well as the innervation and vascularization of the walls of venae cavae and pulmonary veins.

Congenital anomalies of the venae cavae: embryological origin, imaging features and report of three new variants.

Due to the complexity of their developmental stages, the venae cavae may undergo a very large number of congenital anomalies. All the possible abnormalities which, to our knowledge, have been observed in the literature are reported, differentiating those of the superior vena cava and the azygos system, those of the inferior vena cava and the complex anomalies that concern the venous system as a whole. Moreover, we present three new variants: a right double inferior vena cava with azygos continuation of the posterior-medial vein; an agenesis of the superior vena cava with drainage through the azygos and hemiazygos veins to the inferior vena cava; and a double inferior vena cava with hemiazygos and azygos continuation of the left one.

[Contribution of Doppler exploration of ductus venosus flow]. / Intérêt des dopplers veineux chez le foetus.

Among the different means currently available to assess fetal hypoxia and determine the optimal time for fetal extraction in case of intra-uterine growth retardation (IUGR), Doppler measurement of blood flow in the ductus venosus (DV) is one of the most promising. The DV is one of the three fetal circulation shunts observed in utero. Approximately 55% of the oxygenated blood flowing from the umbilical vein to the foramen ovale and the left cavities short circuits the hepatic circulation via the DV. This oxygenated blood is preferentially directed to the myocardium and the brain. Measurement errors (suprahepatic veins, umbilical veins) can lead to erroneous diagnosis of defective DV. Inversely, there is a normal physiological reverse flow in the suprahepatic veins and the inferior vena cava not present in the DV. In case of fetal hypoxia, the proportion of oxygenated blood increases due to increased flow from the umbilical vein into the DV, increasing the proportion of oxygenated blood delivered to the heart and brain instead of the liver. This corresponds to fetal adaptation to hypoxia and the spectrum of the DV thus normally includes a positive wave. When the fetus is unable to adapt to hypoxia, there is an alteration of the right heart function observable in the DV spectrum with diminished diastolic flow or even zero or reverse flow. Anomalous CV flow is a sign of major deterioration of the fetal status before development of severe anomalies. For many, the short-term variability implies immediate extraction of the fetus. Certain well trained teams combine DV flow with other information such as the biophysical examination of the fetus, the quality of the amniotic fluid, visual and automated growth retardation measurements, and other Doppler measurements for decision making. Doppler measurements of the DV, disclosing IUGR or made during surveillance of IUGR, are theoretically made only if other Doppler findings such as arterial redistribution are abnormal. Doppler assessment of DV flow is not a first intention procedure and only concerns a small high-risk fetal population. Experience and good knowledge of fetal anatomy and the Doppler technique are required (it is easy to confuse the physiological spectrum of the suprahepatic veins with a negative wave corresponding to pathological DV flow).

Relationship in the chick of the developing pulmonary vein to the embryonic systemic venous sinus.

Previous studies have shown that the relationship of the systemic venous sinus (sinus venosus) to the developing pulmonary vein are very similar in mice, rats, and man, with the pulmonary vein gaining access to the heart through a persisting segment of the dorsal mesocardium. It has been suggested that this process differs in avian development, with the pulmonary vein being connected to the systemic venous sinus with subsequent transfer to the left atrium. Here we have investigated the anatomical sequence of events in the chick, using serial histological sections and microdissection followed by scanning electron microscopy. We examined a temporal series of chick embryos, ranging from Hamburger and Hamilton stage 15 to stage 30. Although there are some differences in detail, the development of the pulmonary venous connections in the chick was found to be directly comparable to that already described in eutherian mammals. In both mammals and the chick, the dorsal mesocardial connection, which connects the primitive atrium to the posterior thoracic wall, forms a fixed point through which the pulmonary vein gains access to the atrial compartment of the heart, only varying if the connection itself is anomalous. The tributaries of the systemic venous sinus and the primary atrial septal structures develop around the dorsal connection.

Morphological adaptation of the cardiovascular system in fetal rats during late gestation.

The aim of this study was to evaluate morphological changes of the cardiovascular system in fetal rats during late gestation. We used the rapid whole-body freezing technique for rats of day 17 through 21 of gestation. The right and left ventricular volumes increased markedly and significantly during this period by about 11- and 24-fold, respectively. Although the right ventricular volume was 108% larger with statistical significance than the left ventricular volume on day 17, they were almost equal after day 19. The length of the primum septum of the atrium significantly increased by 92% within 4 days, but the opening distance of foramen ovale significantly decreased by 14%. The ratio of the inner diameter (the sum of right and left pulmonary arteries to ductus arteriosus) significantly increased from 0.72+/-0.03 on day 17 to 1.17+/-0.07 on day 21. There was also a significant increase in the ratio of the inner diameters of the ascending to descending aorta. These observations suggest that the reduction of the opening distance of foramen ovale reflect the growth of pulmonary arteries.

Anatomy and development of the sinoatrial valves in the dogfish (Scyliorhinus canicula).

BACKGROUND: We describe the adult anatomy and the development of the cardiac sinoatrial valves in the dogfish (Scyliorhinus canicula). METHODS: We use scanning electron microscopy, histological and histochemical techniques in 39 hearts from embryos and adult specimens. RESULTS: The sinoatrial valvular set of the adult dogfish is composed of two transverse valves laterally attached to the sinoatrial junction at their bases. Both valves are composed of two muscular layers, the sinusal and the atrial, whose histological features are similar to the cardiac wall which they face. Collagen bundles, elastic fibers and fibroblasts are present between the muscular layers. The extracellular matrix between the valvular layers also contains sulphated and non-sulphated glycosaminoglycans. The sinoatrial valves develop from two lateral infoldings of the cardiac wall. The left fold is deeper than the right, causing a shift of the sinoatrial communication to the right. The epicardium progressively covers the outer sinoatrial groove and the space between the folds becomes populated by mesenchymal cells. The posterior atrioventricular endocardial cushion is in contact with the base of the left fold until the embryo has about 40 mm TL. CONCLUSIONS: The sinoatrial valves, in the dogfish, develop from lateral infoldings of the cardiac wall. This origin results in histological and histochemical differences between the two muscular layers which constitute the valves of the adult. The comparison of the sinoatrial valve morphogenesis between the dogfish and some higher vertebrates suggests that the right sinoatrial valve, but not the left, is homologous throughout the vertebrate phylogeny.

Development of cardiac musculature in the cranial vena cava of rat embryos.

Development of cardiac musculature in the rat cranial vena cava (common cardinal vein or duct of Cuvier) was examined by immunohistochemistry and transmission electron microscopy. Undifferentiated cardiac myocytes were detected in the cranial vena cava wall of rat embryos after 12.5 days post-coitum (dpc). The tunica media of the cranial vena cava was composed of cardiac myocytes after formation of the endothelium. Therefore, the cranial vena cava may be not only a part of the venous system but also of the heart. Myocytes in the cranial vena cava contained developing myofibrils, mitochondria and intercalated discs similar to those found in the myocytes in heart. Striated myofibrils began to differentiate as soon as myocytes appeared in the vena cava wall, and myocytes with differentiating myofibrils occur in the wall as the first component of the tunica media at 12.5 dpc. We concluded that the cardiac musculature in the vena cava is not a secondary extension into the tunica media after birth only in the rat, but a basic structure formed in all mammals during early embryonic development.

Patterns of expression of sarcoplasmic reticulum Ca(2+)-ATPase and phospholamban mRNAs during rat heart development.

This study reports the clonal analysis and sequence of rat phospholamban (PLB) cDNA clones and the temporal appearance and patterns of distribution of the mRNAs encoding sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA2) and PLB in the developing rat heart determined by in situ hybridization. Both proteins play a critical role in the contraction-relaxation cycle of the heart. SERCA2 mRNA is already abundantly present in the first stage studied, in the cardiogenic plate of the 9-day-old presomite embryo, before the occurrence of the first contractions. This very early expression makes it an excellent marker for the study of early heart development. Subsequently, SERCA2 mRNA becomes expressed in a craniocaudal gradient, being highest at the venous pole and decreasing in concentration toward the arterial pole of the heart. PLB mRNA can be detected in hearts from 12 days of development onward in a virtually opposite gradient. In essence, these patterns do not change during further development. PLB mRNA levels remain highest in the ventricle and outflow tract, whereas SERCA2 mRNA prevails in the inflow tract and atrium, although the difference between atrium and ventricle becomes less pronounced. These observations are compatible with a model in which the upstream part of the heart (inflow tract and atrium) would have a greater capacity to clear calcium and hence would have a longer duration of the diastole than the downstream compartments (atrioventricular canal, ventricle, and outflow tract), similar to the observed pattern of contraction of the embryonic heart. The sinoatrial and atrioventricular nodes do not reveal an expression pattern of SERCA2 and PLB mRNA that allows one to distinguish them from the surrounding atrial working myocardium. However, the ventricular part of the conduction system, comprising atrioventricular bundle and bundle branches, are almost devoid of SERCA2 mRNA.

[Development of the ascending lumbar and azygos veins in human embryogenesis]. / Razvitie voskhodiashchei poiasnichnoi i neparnoi ven v émbriogenezecheloveka.

The ascending lumbar and azygos veins make a single magistral, but with different topography in the abdominal and thoracic cavities. The former runs more dorsolateral than the sympathetic trunk, and the latter--more ventromedial. These vessels are of different origin in human embryogenesis. The ascending lumbar vein develops from supracardinal veins of the abdominal cavity, that unite the dorsomedial tributaries of the postcardinal vein. The supramesonephral (thoracic) part of the latter makes the azygos vein trunk. Its beginning in the form of a plexus is determined by anastomosing supracardinal, postcardinal and mesocardinal veins. The mesocardinal vein serves as a longitudinal anastomosis for veins, connecting medial tributaries of the postcardinal vein. Differential peculiarities of its basin over the whole length and topographic peculiarities of the ascending lumbar and azygos veins depend on growth specificity of kidneys and adrenals, as well as on other organs in human embryogenesis.

Computed tomography of vena caval anomalies with embryologic correlation.

Vena caval and left renal vein anomalies are not uncommon and are easily identified by CT, usually in an incidental fashion. A simple classification of these anomalies is presented (Table I). These anomalies become significant only when they are mistaken for pathologic masses or when one is planning surgical or radiologic vascular procedures. Detailed knowledge of these anomalies, in conjunction with the use of dynamic bolus CT, will permit easy diagnosis in nearly all cases.

In situ morphology of the heart and great vessels in fetal and newborn rats.

Morphology of the cardiac chambers and great vessels of fetal and neonatal rats was studied using the whole body freezing technique and by sectioning through the short axis of the heart with a freezing microtome. Compared to the fetal heart, the neonatal heart showed rapid change 2 to 8 days after birth. The ventricular sinus septum was straight in the fetus and became concave to the left ventricle after birth. The right ventricular wall was as thick as the left in the fetus and became thinner rapidly after birth. At the same time, the right ventricular cavity dilated. The right and left pulmonary arteries and pulmonary veins were small in the fetus and enlarged soon after birth. At the same time, the foramen ovale was closed and the diameters of the inferior vena cava and descending aorta were diminished. One-half-mm thick sections were cut serially and then photographed. Ventricular volumes and masses were calculated from summation of the areas of each chambers. Left ventricular mass per body weight increased rapidly after birth, whereas right ventricular mass per body weight remained constant from 0 to 8 days after birth.