Anterior Cardinal Vein Research Articles

Syndrome Sinistre: Left Brachiocephalic Vein Compression and its Neurological Manifestations.

Embryologically, the left brachiocephalic vein (LBV) originates as an anastomotic channel between the right and left anterior cardinal veins. This positions the LBV between the manubrium sterni anteriorly and the innominate artery posteriorly. This pattern of adjacency of the aorta to the LBV is unique to mammals and results from a quirk of evolution. With age, the ascending aorta unfolds, elongates and dilates. Simultaneously, there is a change in the thoracic geometry that reduces the thoracic volume primarily from disc height loss and kyphosis. These transitions progressively compress the LBV. Normally, this compression is circumvented via collateral pathways and "Blood finds a way". However, traversing these circuitous pathways comes at a cost and can result in delayed transit times and venous congestion. While it is possible that compression of the LBV in the setting of adequate collateral channels may fail to provoke any pathologic sequelae, we propose a phenomenon in which such compression in the setting of inadequate collateral circulation may lead to a state of pathologic venous congestion. This anatomic anomaly and its associated clinical features, if identified, can offer a new avenue for treatment options for some of the hitherto unexplained neurologic disorders.

A Persistent Left-Sided Superior Vena Cava Detected on a O-15-H 2 O PET/CT of the Heart.

A persistent left-sided superior vena cava (PLSVC) is an uncommon finding with a prevalence of up to 0.5% in the general population. The PLSVC appears when the left anterior cardinal vein fails to regress as the ligament of Marshall during embryologic development. It is usually asymptomatic and discovered incidentally; however, its recognition is important because it might complicate invasive cardiovascular procedures. In this case, we report an incidental finding of a PLSVC detected on the O-15-H 2 O PET/CT of a patient who was referred for myocardial perfusion imaging.

Elderly man with abnormal chest radiograph after central venous catheter insertion.

A 78-year-old male presented to the emergency department with septic shock. A left-sided internal jugular central venous catheter (CVC) was inserted using ultrasound guidance. A routine post-procedure chest radiograph was obtained to confirm CVC placement (Figure 1). The chest radiograph findings raised concerns for the possibility of an unanticipated carotid artery placement as the intraluminal catheter did not appear to cross the midline and terminated in an abnormal left paramediastinal location. A follow-up computed tomography (CT) scan of the chest was performed to further evaluate line positioning (Figure 2 and 3). The prevalence of left-sided SVC is unknown as it is often silent and detected incidentally on imaging, though estimates range from 0.3% to 3%.1 Paired transient anterior cardinal veins are present during routine fetal development. The left anterior cardinal vein typically involutes and the right anterior cardinal vein enlarges to form the SVC. A left-sided SVC is a congenital anomaly resulting from the failure of the left anterior cardinal vein to obliterate.2 A left-sided SVC typically drains into the right atrium via the coronarysinus, though the precise vascular anatomy may be challenging to delineate in the absence of intravenous contrast.3 Infrequently, it drains into the left atrium causing a right-to-left shunt most frequently without significant cyanosis.3 Inadvertent arterial placement is the principal consideration that should be excluded when a left-sided CVC fails to cross the midline as anticipated. Occasional anatomic variants may exist that can be more readily delineated with the use of cross-sectional imaging if needed. In this case, after confirmation of the anatomical variation and adequate venous placement by CT imaging, the catheter was used without issue or complication.

Sinus coronarius, mikroanatomska studija

INTRODUCTION: Complete appreciation of the cardiac venous system requires an understanding of its embryological basis, its usual patterns of distribution, and its common variations. AIM: The aim of our study was to improve our understanding of the coronary sinus morphometrical and topographical anatomy. METHODS: The investigations were carried out on 25 human hearts (from 11 male and 14 female persons of mean age 59.5; range: 40 to 75 years). The classic anatomical technique of microdissection (using neurosurgical microinstruments) was performed under the stereoscopic microscope on 10 specimens injected with a 10% formaldehyde solution. The arteries and veins of an additional 15 hearts were injected with methylmethacrylate and immersed in a 40% solution of NaOH for corrosion. Following washing out and drying, the obtained vascular casts were examined and measured. RESULTS: Coronary sinus (CS) extends from the opening of the oblique vein of the left atrium into the great cardiac vein, to its empty orifice into the right atrium. The length of CS varied between 22.4 and 41.4 mm (mean 33.0 ± 6.1 mm). The diameter of CS at its beginning was 5.0 - 9.6 mm (mean 6.6 ± 1.3 mm), and its diameter at its atrial mouth varied from 6.6 - 12.0 mm (mean 8.4 ± 1.6 mm). The CS had varied relationships to the branches of the left or right coronary arteries. It extended superficial and above the artery in 16 (64%) hearts, and close superficial to the artery in 9 (36%) cases. Duplication of the superior vena cava associated with an aberrant left hepatic vein was found in one case. The persistent left superior vena cava, which drained into the right atrium via the enlarged coronary sinus, was formed by the persistence of the left anterior cardinal vein. CONCLUSION: Our study shows that the coronary sinus, created in an early stage of embryological development, is an important collecting vessel receiving the main veins of the heart.

A Case Report about Persistent Left Superior Vena Cava: Is it Always Asymptomatic?

A persistent left superior vena cava (PLSVC) is a rare malformation which affects approximately 0.3% - 0.5% of the population and it is presented along with a right-sided superior vena cava in 82.2% of the cases reported [1]. Clinicians diagnose it incidentally by difficulties with pacemaker implantation, central venous catheterization or screening for another etiologies when it is not accompanied by other anomalies it is typically asymptomatic. W. Schummer et al. described the embryogenesis and the anatomic variations of persistent LSVC according to the positioning of a central venous catheter on the chest radiograph: type I, normal; type II, only PLSVC; type IIIa, right and left superior vena cava with connection; type IIIb, right and left superior vena cava without connection [2]. In 92% of individuals with PLSVC, the PLSVC drains into a dilated coronary sinus (CS) and rest 8% drain directly into the left atrium. PLSVC is caused by a failure in the closure of the left anterior cardinal vein during embryogenic development [3]. The coronary sinus (CS) is a vein that transmits venous blood to the right atrium though atrioventricular groove. The CS wall contains atrial myocardium. Thus, its size extensively depends on variability of blood flow and pressure. We present a variant PLSVC with unknown prevalence and a mild platypnea-orthodeoxia syndrome after recovery of COVID-19 related acute respiratory distress syndrome (ARDS).

Co‐Presentation of a Circumflex Retroesophageal Right Aortic Arch and Persistent Left Superior Vena Cava in a Human Cadaver

The present study concerns a unique finding of two cardiovascular anomalies in a 57 y.o. human female Caucasian cadaver whose death was determined as non‐cardiovascular. She presents with a circumflex retroesophageal right aortic arch (CReRAA) that gives rise to an aberrant left subclavian artery from a diverticulum of the proximal descending aorta. A left ligamentum arteriosum completes a vascular ring with the CReRAA around her trachea and esophagus. She also presents with persistent left superior vena cava (PLSVC) amid regular right superior vena cava (SVC) (i.e., double SVC) with an innominate vein bridging the two. Her PLSVC leads to a dilated coronary sinus coursing the posterior left coronary sulcus to the right atrium. Albeit separately rare anomalies, simultaneous presentation of CReRAA and PLSVC appears to be unrecorded. The objective of the present study is to assemble a comprehensive case report illustrating gross presentation, embryological explanation, histological examination, and clinical considerations of the CReRAA co‐presenting with PLSVC.Gross presentation of the CReRAA and PLSVC was compared to anatomical norm, and embryological explanations for the anomalies were hypothesized. Cross‐sectioned segments of the trachea, esophagus, and coronary sinus were examined grossly and histologically for anomalous changes in lumen diameter and tissue integrity.Embryologically, CReRAA is caused by left 4th branchial arch regression with right dorsal aorta persistence. As a result, the right 4th branchial arch becomes the aortic arch giving off its typical branches in reverse succession before branching an aberrant left subclavian artery from the vestige of the distal left dorsal aorta (Kommerell’s diverticulum) at the proximal descending aorta. The left 6th branchial arch regresses to form ligamentum arteriosum. PLSVC results from a persisting caudal portion of the left anterior cardinal vein which normally regresses as the ligament of Marshall to separately form the coronary sinus. Gross measurements reveal tracheoesophageal constriction from the CReRAA vascular ring and coronary sinus dilation from the PLSVC. Histological analysis of the tracheoesophageal and coronary sinus tissues has yet to be performed.This case report substantiates known clinical implications of CReRAA and PLSVC in new light of being co‐presented. Complete vascular rings can be challenging to identify since their atretic components are not fillable with contrast medium and present serious clinical sequelae (chiefly respiratory distress and esophageal dysphagia) from tracheoesophageal compression. As such, CReRAA should be a differential diagnosis when these otherwise unexplained symptoms occur. Additionally, PLSVC has important implications for placing cardiovascular implantable electronic device (CIED) transvenous leads through the right SVC via the left subclavian vein. When encountered, alternative access through the PLSVC and into the heart via the coronary sinus or right subclavian venous access should be considered. Increasing available knowledge of such anomalies benefits both physicians and patients.

Two Cases of Cardiac Implantable Electronic Device Placement via Persistent Left Superior Vena Cava.

Persistent left superior vena cava (PLSVC) is the most common variation of anomalous venous return to the heart and present in 0.1–0.5% of the general population. The left anterior cardinal veins typically obliterate during early cardiac development but failure of involution results in PLSVC. It is an asymptomatic congenital anomaly, usually discovered while performing interventions through the left subclavian vein or during cardiovascular imaging. PLSVC can be associated with cardiac arrhythmias and congenital heart disease. We present two cases of PLSVC: first, a 68-year-old male who presented with complete heart block, for which a temporary pacemaker was initially inserted followed by a permanent pacemaker; second, a 53-year-old female with a history of hypertension and ischemic cardiomyopathy with a left ventricular ejection fraction of 25%, and a survivor of sudden cardiac death, who underwent an implantable cardioverter-defibrillator (ICD) for secondary prevention.Both cases of PLSVC were detected incidentally during the transvenous approach to the heart. PLSVC was suspected by the unusually left medial position of the lead, while cineflouroscopy showed the venous trajectory toward the coronary sinus and drainage into the right atrium. It is technically difficult to cross the wire through the tricuspid valve when coming from the PLSVC and coronary sinus without making a loop in the right atrium, which is known as a wide loop technique.PLSVC is an uncommon anomalous anatomical variant and should be recognized appropriately by specialists who frequently carry out procedures through the left subclavian vein, such as implantation of permanent pacemaker, ICD and cardiac resynchronization therapy. It should also be recognized that wide loop formation of the right ventricular lead in the right atrium is helpful to cross the tricuspid valve and to affix the lead in the right ventricle.LEARNING POINTSPersistent left superior vena cava is an anatomical variant that should be recognized by specialists who frequently carry procedures through the left subclavian vein (e.g. implantation of a permanent pacemaker, implantable cardioverter-defibrillator and cardiac resynchronization therapy).Maneuvers like wide loop formation of the right ventricular lead in the right atrium is helpful to cross the tricuspid valve and to affix the lead in the right ventricle.The cardiac imaging specialist should also suspect and rule out PLSVC on encountering a dilated coronary sinus on any imaging modality

Percutaneous Occlusion of Right Partial Anomalous Pulmonary Venous Connection with Dual Drainage to the Innominate Vein and the Left Atrium: A Unique Anatomical Finding

A 43-year-old woman with a past medical history of aortic coarctation surgically repaired at the age of 3 years using an end-to-end anastomosis, presented with 2 years complain of increasing dyspnea and fatigue with exercise associated to frequent palpitations. During extensive work-up, she was found to have a partial anomalous pulmonary venous connection (PAPVC) with “dual drainage” represented by a communication between the right pulmonary veins draining into the left atrium and the innominate vein via an anomalous vein due to a persistence of early connections between the sinus of the right pulmonary veins and the cardinal veins system in the splanchnic plexus and also a persistence of the proximal portion of the left anterior cardinal vein. She was successfully treated through a percutaneous implantation of a vascular plug occluding the vertical portion of the anomalous vein diverting the flow to the left atrium. To the best of our knowledge, this anatomical variant of partial anomalous pulmonary venous connection with dual drainage has not been previously reported.

Right-to-left shunt secondary to duplicated superior vena cava as etiology of ischemic stroke

Duplication of superior vena cava (SVC) has an estimated prevalence of 0.3%. Incomplete regression of anterior cardinal vein can lead to persistent left superior vena cava (PLSVC) and is associated with chronic hypoxemia and predisposition to systemic embolization from right-to-left shunt. Blood drainage to the left atrium is extremely rare.

PECULIARITIES OF ANLAGE AND DEVELOPMENT OF THE CERVICAL ORGANS DURING EMBRYONIC PERIOD OF HUMAN ONTOGENESIS

Objective: to determine the peculiarities of anlage and development of certain cervical organs during the embryonic period of human ontogenesis.Materials and methods. The study was conducted on 12 series of successive histological sections of the human embryos 4-6 weeks of development (4,0-13,5 mm of the parietal-coccygeal length (PCL). Only those cases were included into the study when a cause of death was not associated with pathology of the organs, vessels and nerves of the neck. The methods of preparation of series of successive histological sections, common and thin dissection under control of binocular lens, graphic and plastic reconstruction, microscopy, and morphometry were used.Results. In the embryos 4,0-4,5 mm long the rudiments of the esophagus, larynx and trachea are determined as pharyngeal derivatives on the level of the first cervical vertebra, although none of the morphological structures that can be used to determine the borders between the rudiments of the respiratory and digestive tubes are found. In front of the rudiments of the respiratory and digestive systems there are big rudiments of the heart and liver, and behind – the rudiments of the cardiac veins, dorsal aorta and vertebral column.During the fifth week of the embryonic development the rudiment of the oral pharynx is in the form of a dilated anterior part of the foregut. The oral fossa which is the initial portion of the oral pharynx is bounded above by the unpaired frontal process, lower – by paired mandibular processes, and from the sides – by maxillary processes. The cervical part of the vertebral column is located dorsally from the rudiment of the pharynx, the larynx rudiment – ventrally, and vascular-nervous bundle of the neck – ventrolaterally. The rudiment of the larynx looks like an oval accumulation of mesenchyme developed due to the closure and separation of the epithelial channel from the ventral wall of the anterior intestine. The fourth brachia arteries are determined on the examined stage of the intrauterine development transformed in the right into the anonymous artery, and in the left – into the aortal arch.In the embryos 9,0-12,0 mm of PCL in the caudal portion of the anterior pharyngeal wall on the level of branching of the tracheal rudiment there is a paired thickening of the mesenchyme in the form of arytenoid rollers with dorsally directed incisures and a transverse roller separating the entrance into the respiratory tube. The epiglottis rudiment is also determined. The venous system of the cervical region is presented by the anterior cardinal veins mainly located ventrally from the vertebral column. The junction of the anterior and posterior cardinal veins results in the formation of the common cardinal veins. At the end of the embryonic period of development the internal and external jugular veins are formed from the cranial portion of the anterior cardinal vein.Conclusions. At the end of the embryonic period of development the pharynx and trachea are not separated clearly, since they are surrounded by the common layer of mesenchyme. The larynx is presented by mesenchyme thickening located directly close to the entrance into the respiratory tube. The main cervical veins are formed from the anterior cardinal veins.

Abstract 17162: Ambient Ultra Fine Particle Exposure Impairs Gut Vascular Barrier via Notch Signaling

Introduction: Ultrafine particles (UFP, d < 0.1 μm), a major sub-fraction of particulate matter (PM 2.5 , d < 2.5μm) in air pollutant, have been reported to increase cardiovascular morbidity. UFP promote endothelial dysfunction/permeability associated with Notch inhibition and degradation of tight junction protein. Gut vascular barrier (GVB) is a distinct protective barrier that inhibits translocations of antigens across the gut lumen, preventing infections by oral digestions. Here, we hypothesized UFP impair GVB by attenuating Notch signaling and disrupting tight junction protein. Method: The transgenic Tg( flk1:mCherry ) zebrafish embryos were immobilized in neutralized tricaine solution and mounted in 2% low melting agarose to perform micro-gavage at 5 days post fertilizations (5dpf). A mA mixture of 10 kD FITC conjugated dextran and phenol red dye wasere micro-gavaged on the intestinal bulb with or without UFP at 25 μg/mL. Anterior trunk and posterior cardinal vein (PCV) post micro-gavage were imaged under a confocal microscope. Notch signaling related genes including the Notch ligand, Dll4, and the target, HES1, and the level of tight junction protein genes zonula occludens-1 (ZO-1) and Occludin (OCLN) mRNA expression following different courses of exposure to UFP were assessed in Human Aortic Endothelial Cells (HAEC) with quantitative RT-PCR., Result: In the control group, the majority of FITC-dextran remained inside the gastrointestinal system. On the other hand, UFP exposure developed a significant accumulation of FITC-dextran in the intersomatic spaces (ISS) between the dorsal aorta (DA) and the PCV. This finding supports evidence of UFP exposure disrupted both the epithelial boundary and the endothelial vascular layer of the gut. In addition, Notch signaling related gene (HES1, DLL4) and the tight junction proteins genes (ZO-1, OCLN) expressions in HAEC were downregulated in concentration and time-course dependent manner by the exposure to UFP. Conclusion: The UFP exposure affected GVB homeostasis and increased endothelial permeability. This finding supports the link between ambient air pollutant exposure to the impairment in the gastrointestinal system.

Role of Semaphorin Signaling During Cardiovascular Development.

Semaphorins are a family of secreted and membrane‐bound molecules that play critical functions in diverse biological processes.[1][1], [2][2], [3][3], [4][4], [5][5], [6][6], [7][7], [8][8], [9][9] SEMA1A/Fasciclin IV is the founding member of the semaphorin family and was first reported in 1992

Large thoracic tumour without superior vena cava syndrome.

A 62-year-old male with long-standing smoking history presented with haemoptysis. Plain chest X-ray showed abnormal findings proximate to the right pulmonary hilum. Bronchoscopy revealed a fragile exophytic tumour of the right wall of the lower third of the trachea, infiltrating the right main bronchus (75% stenosis) and the right upper lobar bronchus (near total occlusion). Contrast-enhanced chest computed tomography demonstrated a 7.2 × 4.9 cm tumour contiguous to the above-mentioned structures, mediastinal lymph node pathology, and a vessel coursing inferiorly to the left of the aortic arch and anterior to the left hilum. Despite the tumour constricting the right superior vena cava (SVC), no signs of SVC syndrome were present. In this case, the patient does not present with SVC syndrome, as expected due to the constriction of the (right) SVC caused by the tumour, since head and neck veins drain through the persistent left superior vena cava (PLSVC). PLSVC is the most common thoracic venous anomaly with an incidence of 0.3% to 0.5% of the general population and it is a congenital anomaly caused by the failure of the left anterior cardinal vein to regress and to consequently form the ligament of Marshall during foetal development. It is associated with absence of the left brachiocephalic vein and in 10% to 20% of cases the right SVC is absent. Two potential draining points of the PLSVC have been previously reported. In the majority of cases PLSVC drains directly into the coronary sinus, but less frequently it drains into the left atrium or the left superior pulmonary vein (LSPV). In cases where the PLSVC drains into the coronary sinus, congenital heart defects are rare. The patient usually remains asymptomatic and PLSVC is an incidental finding during radiographic imaging or medical procedures. When the PLSVC drains into the left atrium or the LSPV, a right-to-left shunt is formed; a condition usually asymptomatic. In some reported cases this PLSVC variant presents with persistent, unexplained hypoxia or cyanosis and embolisation causing recurrent transient ischaemic attacks and/or cerebral abscesses. This PLSVC variant is more often associated with absence of the right SVC and congenital heart abnormalities.

The Current Concepts of the Embryology of the Lymphatic System

The overall lymphatic system is the major factor in maintaining the integrity of our cellular immunity as well as in playing a role in lipid metabolism and hormone transport. There is a major interest in the ability of certain tumors to induce lymphangiogenesis and the potential impact that this may have on treatment. The lymph nodes also play a significant role as prognosticators of survival in cancer patients, and, the more complete our knowledge of this critical system, the better one can appreciate its complexity and function. The best place to start is with the origin of the lymphatic vasculature. In the head and neck, this vascular network arises primarily from the anterior cardinal veins as well as from the intersomitic veins and the superficial venous plexus. Thus, to fully understand lymphangiogenesis, it is necessary to briefly review vasculogenesis and angiogenesis to appreciate how these vessels arise. This review examined the current concepts of the development first of the vascular system and then of the lymphatic system. The review was highly illustrated to assist the reader in understanding the embryology. There also was a brief section noting the congenital abnormalities that may arise when the embryology goes awry.

Progress and prospect of lymphangiogenesis research

During the last twenty years, we have witnessed a rapid progress in the field of lymphatic vascular biology. The increase of lymphatic research has greatly deepened our understanding of the lymphatic system in health as well as in diseases. This review starts with the description of the current understanding of the mechanism underlying lymphatic formation and remodeling in development. In mammals, lymphatic vessel development initiates with the specification of lymphatic endothelial cells from a population of venous endothelial cells in the lateral parts of the anterior cardinal veins. This is followed by the formation of lymph sacs, which undergoes expansion into the primitive lymphatic plexus by the process of lymphangiogenesis. The primary lymphatic network is further remodeled into a mature lymphatic system composed of lymphatic capillaries and collecting lymphatics containing intraluminal valves as well as smooth muscle cell coverage. Several key factors and pathways have been identified to participate in the process, including lymphangiogenic growth factors and receptors, extracellular matrix proteins and cell junction molecules, intracellular signal mediators and transcription factors. It is interesting to find out how these factors coordinate to control collecting vessel formation and maturation, and whether they work in the same pathway or in different pathways controlling specific cellular programs. Secondly, the authors summarize the physiological functions of lymphatic system, including the essential role of lymphatic system in the maintenance of tissue fluid homeostasis. Defective lymphatic development or damage of the lymphatic system resulting from surgery or infection leads to lymphedema. In immune system, lymphatic vessels are crucial for the leukocyte trafficking from peripheral tissues to their draining lymph nodes and for the drainage of soluble antigens. Furthermore, the absorption of dietary nutrients is critically dependent on the lymphatic vessels in intestines, also known as lacteals in intestinal villi. Finally, the authors have discussed the involvement of lymphatic system in several diseases including tumor metastasis, inflammation and cardiovascular diseases. It has also been well established that tumor associated lymphangiogenesis promotes lymphogenous tumor metastasis. Although the molecular players responsible for lymphatic vessel growth is similar in development and tumor, there are distinct characteristics of tumor-associated lymphangiogenesis, including the lack of lymphangiogenic growth factor gradient in tumor. Therefore, tumor-associated lymphatics are patchy, disorganized without a hierarchical vascular pattern, and also not homogenously distributed within tumors. In addition, inflammation is often associated with profound lymphatic vessel growth and remodeling, and there are also evidence showing that the abnormal lymphatic growth is implicated in cardiovascular diseases. In spite of the recent progress in the research field of lymph-vascular biology, there is still lack of effective drugs for the prevention and treatment of lymphedema and lymphatic related diseases. Thus, continued support and further increase in research investment in this field are very much wanted to better understand the cellular events and molecular players involved in lymphatic vessel growth and function at both physiological and pathological conditions.

PERSISTENT LEFT SUPERIOR VENA CAVA IN PATIENT WITH PAROXYSMAL ATRIOVENTRICULAR NODAL REENTRANT TACHYCARDIA

Persistent left superior vena cava (PLSVC) is a rarely occurring congenital anomaly with the incidence of 0.3% in general population. This anomaly results from the persistence of the left anterior cardinal vein. In 90% of cases blood from PLSVC flows into the coronary sinus and then to the right atrium. It may complicate the placement of central vein catheters in the jugular and subclavian veins and, as such, cardiologists should be aware of the existence of this anatomic variant. Here we describe an adult patient with persistence of the left superior vena cava identified during made echocardiography test in a 57-year-old male patient with paroxysmal atrioventricular nodal reentrant tachycardia (AVNRT) who was admitted to a cardiac ward on a regular basis for ablation procedure.

Double Superior Vena Cava: A Case Report

During routine dissection, a double superior vena cava, which is commonly known as persistent left superior vena cava (PLSVC) was observed in a 75‐ year‐old female cadaver. PLSVC drained into the right atrium through the coronary sinus. Coronary sinus was abnormally dilated to accommodate the large volume of venous blood reaching it through the PLSVC. Three sets of veins; common cardinal, anterior cardinal and posterior cardinal veins are involved in the normal development of the vena cavae. Embryological basis of PLSVC and its clinical significance in heart diseases will be discussed.

Our encounter with left superior vena cava.

Sir, A Left Sided Superior Vena Cava (LSVC) is usually an incidental finding, which is revealed during insertion of central venous lines in asymptomatic patients. However if detected, the patient should be investigated for the presence of congenital cardiac ailments. We had a 28 years male who had a left sided loculated pleural effusion, who was posted for a left sided open decortication under general anaesthesia. For monitoring central venous pressure and in anticipation of use of vasoactive drugs, we placed a 7-French triple lumen catheter in the left subclavian vein by supraclavicular approach under ultrasound guidance. Post-operatively we obtained a chest radiograph to confirm the position of the central venous catheter [Figure 1]. His resting heart rate was 64/min, and oxygen saturation on room air was 99%.Figure 1: Post-operative chest radiographSuspecting a persistent LSVC (PLSVC), we advised a two-dimensional (2D) echocardiogram to find any associated congenital cardiac anomaly. The echo revealed normal sized chambers, no septal defects with good biventricular function. Retrospectively, we reviewed the computed tomography scan that was done at another hospital. It revealed a LSVC with an absent of SVC on the right [Figure 2].Figure 2: Computed tomography chest showing isolated left superior vena cavaPersistent left superior vena cava is the most common thoracic venous anomaly encountered. The most common presentation is presence of both LSVC and right SVC.[1] However, isolated LSVC is usually associated with atrial septal defect, bicuspid aortic valve, coarctation of the aorta, coronary sinus ostial atresia and cor triatriatum.[2] The prevalence of PLSVC in the general population is 0.3–0.5%, and about 12% in patients with congenital heart diseases.[3] Presence of PLSVC is the result of failure of regression of left anterior cardinal vein in the embryological state, which normally forms the ligament of Marshall.[4] LSVC is not clinically important if it is not associated with other cardiac anomalies. It is revealed during central venous catheter placement, thoracic surgery, and imaging for a cardiothoracic condition or as a finding on autopsy A PLSVC usually drains in the coronary sinus. Hence, a dilated coronary sinus on 2D echocardiography should alert the cardiologist to look for a LSVC as well, even though there are other causes.[5] A cardiac magnetic resonance imaging is helpful in detecting venous anomalies and the course of abnormal veins. Radiologically, a widened aortic shadow, paramediastinal bulge or a low density line along the upper left margin of the heart on a postero-anterior view could be due to an LSVC but this requires an extremely high index of suspicion.[6] The most common presentation of a LSVC is presence of both right and left SVC in the same patient. In the presence of a right SVC along with LSVC, the abnormality can be missed unless the catheter inadvertently enters the LSVC, during catheter placement instead of right. If the right SVC is absent, the condition is called Isolated PLSVC.[7] During coronary artery bypass grafting (CABG), the surgical field will be filled with blood in the presence of LSVC and hence, the SVC needs to be ligated or separately cannulated. A PLSVC can lead to steal of solution during retrograde cardioplegia, due to which it is considered a relative contraindication for retrograde cardioplegia. While passing a Swan-Ganz catheter for a cardiac surgery, if the patient develops serious arrhythmia (at times ventricular fibrillation), a suspicion of LSVC should rise. Hence, it is important to know about LSVC during workup for a CABG. The LSVC can create a problem while performing a permanent pacemaker implantation or during an implantable cardioverter placement via left subclavian approach. Serious arrhythmias, coronary sinus thrombosis and cardiac arrest have been reported due to inadvertent LSVC canulation, especially after Swan-Ganz, chemoport or peripherally inserted central venous catheters for chemotherapy, haemodialysis catheters, and pacemaker placement. Hence, in the interest of the patient, the line should be removed and the other site or vein should be used.[8] However, single chamber pacemakers have been successfully, placed under fluoroscopy.[9] Therefore, the knowledge of PLSVC is important for anaesthesiologists and intensivists so that they do not get confused with the radiological picture after central venous cannulation and can evaluate the patient further. Agitated saline injection via left antecubital vein (Bubble study) and performing transthoracic echo is a safe, harmless and inexpensive test that can help in the detection of LSVC in suspected patients.[10]

Abstract 86: Heterozygous expression of an oncogenic Pik3ca mutation during murine development results in fatal embryonic and extra-embryonic defects

Abstract The PI3K/Akt signalling pathway regulates many important cellular functions including proliferation, migration, survival and angiogenesis. The PIK3CA gene, encoding the p110α catalytic subunit of the PI3K enzyme, is somatically mutated in a range of human cancers and overgrowth syndromes. We have previously described a novel mouse model with a Cre-recombinase (Cre)-mediated knock-in of the common cancer-associated Pik3ca(H1047R) mutation that can be targeted to selected tissues using various Cre-expressing mouse strains. As the mutation is knocked in to the endogenous gene, the mutant protein is expressed at normal physiological levels. We have used the Cre-deleter mouse to induce expression of the Pik3ca(H1047R) mutation ubiquitously from the 2-cell stage of development. This results in embryonic lethality by E10.5 with embryos at E9.5 demonstrating stunted growth, failed ‘turning’ and abnormal cardiovascular development in both the embryo proper and extraembryonic yolk sac. These tissues also showed increased expression of vascular endothelial growth factor (VEGF) family proteins. We then selectively targeted the mutation to the endothelial cells of the developing embryo using the Tie2-Cre mouse strain. No Tie2-Cre:Pik3ca(H1047R) mutant embryos survived to E11.5 and at E10.5, while successfully turned, embryos were severely underdeveloped and no longer viable. At E9.5, vascular remodelling was disorganised and truncated in the embryo proper and yolk sacs. Development of the heart was also affected with clear disruption to anterior cardinal vein and dorsal aorta development. Our results demonstrate the importance of PI3K/Akt signalling in embryonic development and cardiovascular formation in the mouse. The observed cell autonomous role in vessel development was further confirmed upon targeted expression to endothelial cells while the increased expression of various VEGF family proteins suggests probable crosstalk between the PI3K/Akt and VEGF signalling pathways during cardiovascular development. The lethality associated with expression of Pik3ca(H1047R) mutation during development likely explains the lack of inherited germline PIK3CA mutations in humans. Citation Format: Lauren M. Hare, Quenten Schwarz, Rajendra Gurung, Karen G. Montgomery, Christina Mitchell, Wayne A. Phillips. Heterozygous expression of an oncogenic Pik3ca mutation during murine development results in fatal embryonic and extra-embryonic defects. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 86. doi:10.1158/1538-7445.AM2014-86

Embryological considerations on a case of coexistence of persistent left superior vena cava and partially left inferior vena cava

The persistent left superior vena cava (PLSVC) is the most common venous thoracic congenital anomaly. The PLSCV generally drains into the right atrium, which it reaches through a dilated coronary sinus. Its presence is usually unrecognized, until a venous approach is performed. Abnormalities of the inferior vena cava (IVC) are rare (0.2-0.3% of healthy subjects and 0.6-2% of patients with cardiovascular defects). A single left IVC (LIVC) is very rare (11.9% of all the abnormalities) [1]. To the best of our knowledge, the coexistence of PLSCV and LICV has not been previously described. We present a case of a 32-year-old woman on hemodialysis for more than 12 years. An angiography demonstrated both a normal right SVC and a PLSCV and a single IVC with a lower left course, an intermediate circumaortic ring and an upper normal right course. The double SVC can be consequent to the failed development of the anastomosis between the anterior cardinal veins and the patency of the caudal part of the left anterior cardinal vein forming the PLSCV. As to the partially LIVC, its iliac and subrenal parts can be the results of the persistence of the left supracardinal vein. The circumaortic venous ring might indicate that a persistent intersupracardinal anastomosis receiving the left and the right renal veins was maintained around the abdominal aorta [2], while the superior part represents the normal right subcardinal and hepatic derivatives. The existence of anomalies should be considered, as they can have important implications in invasive procedures such as venous catheter placement, and may represent a speculative bridge between clinicians and embryologists.