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Development and anatomy of the venous system
Published in Peter Gloviczki, Michael C. Dalsing, Bo Eklöf, Fedor Lurie, Thomas W. Wakefield, Monika L. Gloviczki, Handbook of Venous and Lymphatic Disorders, 2017
The origin of the azygos vein is not constant. It may arise from the back of the inferior vena cava at the level of the renal veins or it may be the continuation of the right ascending lumbar vein (Figure 2.11). The azygos vein ascends on the right side of the body until the fourth thoracic vertebra and then passes anteriorly to join the superior vena cava. Major tributaries of the azygos vein are the right superior intercostal, the hemiazygos, and the accessory hemiazygos veins. The hemiazygos vein courses on the left side of the vertebral column and its origin is similar to that of the azygos vein. At the level of the eighth thoracic vertebra, it crosses the column and joins the azygos vein. Often, the left renal vein communicates with the hemiazygos vein. The accessory hemiazygos vein descends left to the vertebral column and parallel with the azygos vein. Proximally, it anastomoses with the left brachiocephalic vein and ends distally when it joins to the azygos or the hemiazygos veins at the level of the seventh thoracic vertebra. The azygos veins drain the intercostal veins on both sides, receive several visceral tributaries, and freely anastomose with the vertebral venous plexuses. The azygos veins and their tributaries provide important collateral circulation in the face of superior or inferior vena cava obstruction.
Chest imaging
Published in Sarah McWilliams, Practical Radiological Anatomy, 2011
o The hemiazygos runs up on the left and crosses the mid-line to join the azygos at T9 or higher. The veins receive the intercostal veins and drain the posterior walls of chest and abdomen plus the mediastinal organs (Figs 3.19 and 3.20).
Persistent Left Superior Vena Cava: Why is Prenatal Diagnosis Important?
Published in Fetal and Pediatric Pathology, 2022
Ayşe Keleş, Osman Yılmaz, Gülşah Dağdeviren, Özge Yücel Çelik, Aykan Yücel, Dilek Şahin
Persistent left superior vena cava (PLSVC) is the most common variation of the thoracic venous system [1,2]. It is found in 0.3%–0.5% of the general population and 4%–8% in those with congenital heart disease (CHD) [3,4]. In the embryonic period, anterior cardinal veins perform the venous drainage of the cephalic region and upper extremity. Except for a small part that constitutes the left superior intercostal vein, the left anterior cardinal vein regresses in the eighth week of embryogenesis. Failure of this regression results in PLSVC [4,5]. In most cases, the right and left superior vena cava coexist. The specific combination of a persistent LSVC and non-right superior vena cava was reported to be 0.05% in an autopsy series [6,7]. PLSVC typically empties into the right atrium via the coronary sinus, but may empty directly into the left atrium [8].
Retroesophageal left brachiocephalic vein in tetralogy of fallot: an anomalous course depicted on computed tomography angiography
Published in Acta Cardiologica, 2022
Mansi Verma, Rishabh Khurana, Amarinder Singh Malhi, Sanjeev Kumar, Shyam S. Kothari
The LBCV normally courses obliquely downwards anterosuperior to aortic arch and its branches and joins the right BCV to drain into SVC. Left BCV coursing posterior to oesophagus is rare with incidence of ∼ 0.19% in association with congenital heart diseases [1]. The various cardiovascular associations include VSD with or without pulmonary atresia, right aortic arch and patent ductus arteriosus [1]. The retroesophageal course of left BCV can be associated with genetic anomalies including 22q11 deletion. Hence, identification of this anomaly suggests the need for genetic testing. The proposed mechanism for such an anomalous course is the interruption of superior capillary plexus between right and left anterior cardinal veins with failure of development of alternative inferior capillary plexus. Instead, the connection between accessory hemizygous and left superior intercostal vein persists [1]. The identification of this anomalous course is important for clinicians as its accidental manipulation during posterior mediastinal surgeries can lead to intraoperative bleeding. It can also lead to technical difficulties during insertion of transvenous pacemaker and central venous line via a left arm approach [2]. This case highlights the role of computed angiography in depicting anomalous venous anatomy which can have potential clinical implications.
Insertion of a totally implantable venous access port in a patient with persistent left superior vena cava (PLSVC)
Published in Acta Chirurgica Belgica, 2018
Julie Van Walleghem, Sofie Depuydt, Stijn Schepers
Persistent left superior vena cava (PLSVC) is the most common embryological malformation of the central venous system, reported in 0.3–0.5% of the general population [1]. Usually a PLSVC is asymptomatic and an incidental finding during placement of a central venous access device; however, patients are at increased risk of developing cardiac arrhythmias, due to the associated anomalous configuration of the embryological conductive tissue. Given the aging patient population and growing use of central venous access devices, physicians will be increasingly confronted with anatomical variations of the cardiac venous return. The existence of a PLSVC is suggested by periprocedural fluoroscopy that shows a left paramediastinal guidewire pathway after an uncomplicated venous puncture, nonetheless the presence of a large left superior intercostal vein, accessory hemiazygos vein, internal mammary vein or the occurrence of a venous perforation can lead to a similar finding.