Hemiazygos Research Articles

Suprarenal interrupted inferior cava with azygos continuation in a patient with pulmonary embolism: a case report

Abstract Background Interrupted inferior vena cava (IVC) is a rare developmental defect characterised by azygos continuation following failure of fusion of one or more of the component parts of the embryological IVC. It occurs in approximately one in 5000 of the general population. It is usually an isolated finding and is generally asymptomatic. Case Summary A 42-year-old patient presented for further clarification of syncope with a four-day history of persistent exertional dyspnoea. Computed Tomography (CT) revealed a central pulmonary artery embolism on both sides, with prominent azygos and hemiazygos veins and paravertebral collaterals. For further clarification, a magnetic resonance imaging (MRI) scan was performed, where hypoplasia or stenosis of the inferior suprarenal vena cava was noted. There were collaterals of the azygos and hemiazygos veins. The finding was consistent with the picture of a venous abnormality in the sense of an "interrupted IVC (suprarenal) with azygos continuation." Discussion In the case of an isolated interrupted IVC, the patient is usually asymptomatic, and the vascular anomaly itself does not mandate any treatment. This variation should be considered, especially in young patients with deep venous thrombosis (DVT) when no other reason for thromboembolism is evident. To prevent vascular events such as DVT or pulmonary embolism, lifelong anticoagulation therapy is recommended. An interrupted IVC can also cause procedural difficulties during right heart catheterisation, electrophysiological studies, cardiopulmonary bypass surgery, femoral vein catheter advancement, IVC filter placement, and temporary pacing through the transfemoral route.

Anatomical variants of the retroaortic left renal vein

BackgroundAnatomical variants of the left renal vein (LRV), such as the retroaortic (RLRV) and circumaortic (CLRV) course, are of surgical importance. Different morphological and topographical possibilities of the RLRV could occur. It was aimed at documenting the anatomical variables of the RLRV. MethodA retrospective study on 375 computed tomography angiograms was performed. Five different anatomical types of LRV were documented: preaortic types 1 and 2 and retroaortic types 3–5. ResultsIn 344/375 cases, preaortic LRVs were found. In 31/375 cases, different types of RLRV were found: type 3a – single RLRV, 41.94%; type 3b – single RLRV with bifid caval end, 9.68%; type 3c – single RLRV with trifid caval end, 3.23%; type 4a – CLRV with extrahilar origin, 29.03%; type 4b – CLRV with renal sinus origin, 12.9%; type 5 – triple LRV (one preaortic LRV and two RLRVs), 3.23%. Reference vertebral levels were recorded for the prevertebral segment of the RLVR. The vertebral level of type 3a varied from the L1/L2 disc to the upper third of the L4 vertebra. Type 3b was found in 3/31 RLRV cases; in one of these, the hemiazygos vein was inserted by two roots into the LRV and its upper caval end trunk. There was a significant statistical association between type 3b and the vertebral level, all cases being centered on the middle third of the L4 vertebra. ConclusionsNew morphological possibilities of the LRV were distinguished, and a new anatomical classification system of the RLRV results. The RLRV variant should be documented case-by-case as it has its anatomical variables.

Variations of azygos vein: a cadaveric study with clinical relevance.

The azygos vein can be formed as a single root, two roots, and three roots, namely lateral, intermediate and the medial roots respectively. The hemiazygos vein and the accessory hemiazygos vein are the tributaries of azygos vein rather than its left side equivalents. Its variations, especially in young persons without any relevant risk factors, may result in thromboembolic illness. This study aimed to describe the morphological and morphometric variations of azygos system of veins. The present study was conducted on thirty formalin fixed adult human cadavers by dissecting azygos vein from formation to termination and variations were noted. The azygos vein was formed by a single root in 56.7%, by two roots: the lateral root and intermediate root in 36.7% cases and by the lateral root and medial root in 6.6%. The vertebral level of termination of azygos vein was seen at the level of T4 vertebrae in 70% cases, at the level of T3 vertebrae in 20% of cases and at the level of T5 vertebrae in 10% cases. The course of azygos vein was varying in 13.3%. These morphological variations can be useful while performing mediastinal surgery, mediastinoscopy, surgery of the deformations of the vertebral column, neurovascular surgeries of the retroperitoneal organs, disc herniation and fracture of thoracic vertebrae.

Orthostatic proteinuria due to inferior vena cava interruption without nutcracker phenomenon in an old obese female: a case report and literature review

BackgroundNutcracker syndrome (NCS) caused by left renal vein (LRV) entrapment, is one of the most common causes of orthostatic proteinuria. In stereotype, orthostatic proteinuria is often accompanied by left renal vein obstruction and is found in young and underweight individuals. Here, we report a rare case with orthostatic proteinuria in an old obese female caused by a rare type of congenital inferior vena cava (IVC) interruption.Case presentationA 65-year-old obese woman, who suffered from fluctuated proteinuria, had been misdiagnosed as chronic glomerulitis for 30 years. Instead of having any sign of NCS, she had a unique type of IVC interruption. Most venous blood from infrarenal IVC and right kidney drained into her LRV, and then through the expanded communicating vessel, drained into the left ascending lumbar vein which extended as hemiazygos vein. To the best of our knowledge, this is one of the first cases reported of orthostatic proteinuria attributed to the subsequent hemodynamic irregularity caused by IVC interruption without nutcracker phenomenon.ConclusionAdult-onset orthostatic proteinuria is relatively rare, hard to be recognized and could be misdiagnosed as chronic glomerulonephritis. The case provided a novel differential diagnostic condition for those who suffered from fluctuated proteinuria of unknown causes.

Azygous Venous System - Anatomical Variation and Its Clinical Significance

Introduction: Azygous venous system is the system of unpaired veins comprising of the azygous vein, the hemiazygous vein and accessory hemiazygous vein1. They are para vertebral in position, provided with valves and drain most of the blood from the thoracic and posterior abdominal walls. They communicate with the venacaval system infront and vertebral plexus behind. It connects the superior vena cava with the inferior vena cava. The azygous vein is inconstant in the mode of origin. Aim: To explore the anatomical variations in the course of azygous system of veins. Material and methods: The present study was done in the Department of Anatomy, Apollo institute of Medical sciences and Research, Hyderabad over a period of 2 years. The present study was conducted on 12 cadavers (irrespective of age and sex). The course of the azygos venous system in these 12 cadavers was carefully observed and documented. Results: Anatomical variation was found in two cadavers. Discussion: The azygous system of veins arises from a pair of longitudinal venous lines called right and left azygous venous lines on each side of the aorta1. On each side of the azygous venous lines lies two parallel primitive lines called right and left sub cardinal and posterior cardinal veins. It forms an important route for collateral circulation in venacaval occlusion such as in portal hypertension. It serves as the main collateral channel to shunt the blood from the upper half of the body to the inferior venacaval in case of superior vena caval obstruction. Conclusion: Identification and understanding of these variations are important during preoperative radiological investigations and surgical procedures especially spinal surgery between T7 and T12 to avoid injury which may lead to postoperative haematomas Keywords: Azygous venous system, azygous vein, venacaval system.

Incidental CT diagnosis of hemiazygos vein anatomical variant

Anatomical variants of azygos-hemiazygos system are common; in particular hemiazygos and accessory hemiazygos veins are variable in their anatomy and drainage. It is important to detect the variations of azygos-hemiazygos system especially in the computed tomography (CT) and magnetic resonance (MR) imaging of mediastinum, because they may be misdiagnosed for lymphoadenopathy, aneurysm and other abnormalities such as neoplasm. In our short communication CT of brain, chest, abdomen and pelvis with and without contrast agent administration allowed us to diagnose incidentally a hemiazygos vein variant in a patient that complained another disease. MPR, MIP and volume rendering reconstructions were very useful to delineate this anatomical variation.

Azygos vein thrombosis despite rivaroxaban therapy in a patient with breast cancer: A rare entity.

In the light of this case, azygos and hemiazygos veins should be evaluated carefully in thorax CT scans. This rare case is also important in terms of the occurrence of AVT in a patient receiving rivaroxaban therapy. The outcomes and recurrence rates of these patients should also be reported for the decision of anticoagulant treatment.

RETROAORTIC LEFT RENAL VEIN OR POSTERIOR NUTCRACKER SYNDROME: A RARE ANOMALY

The term "Retroaortic Left Renal Vein" refers to a left renal vein that passes behind the abdominal aorta, and this anomaly is a rather unusual occurrence. It has been suggested that retroaortic left renal vein may cause symptoms such as haematuria and abdominal or ank pain. Urological symptoms are likely due to increased pressure in the left renal vein secondary to the posterior nutcracker phenomenon. We describe a highly uncommon case of a 35 year old woman who was admitted via the emergency department due to left sided ank pain for several days. A thorough examination with Contrast-enhanced CT revealed left renal vein compressed in between abdominal aorta and anterior margin of L1 lumbar vertebral body causing severe compression and mild proximal dilatation of left renal vein, with multiple venous collaterals majorly draining into the hemiazygos vein and the rest in inferior vena cava. The left gonadal vein appeared dilatated. These features were suggestive of posterior nutcracker syndrome

Right upper lobe agenesis associated with dextroposition of heart and ectopic kidney in an adult patient attending pulmonary medicine outpatient department: A rare case report from South India

Pulmonary agenesis is a rare congenital anomaly that results from the unsuccessful growth of the primitive lung buds. A case of lung agenesis was first reported in 1673 during an autopsy. Pulmonary agenesis includes agenesis, aplasia, and hypoplasia as the three most common types. The survival rate is <50% by the age of 5 years in case of agenesis. Fifty percent of the cases of lung agenesis are associated with various congenital defects such as cardiovascular, central nervous system, gastrointestinal, genitourinary, skeletal, Down syndrome, and Klippel–Feil syndrome. Here is the case of a 28-year-old male who presented with on-and-off cough and dyspnea for 3 years. On systemic examination, the patient had signs suggestive of loss of right lung volume. Chest x-ray showed right side volume loss with ipsilateral mediastinal shift with compensatory hyperinflation of the left lung. Computed tomography (CT) thorax with abdomen was suggestive of dextroposition with absent right upper lobe parenchyma, right upper lobe bronchus, right upper lobe artery, and superior pulmonary vein with the absence of hemiazygos vein with ectopic left kidney in the pelvis. Early identification of pulmonary agenesis is vital in preventing fibrosis in patients with unilateral lungs which might develop as a result of recurrent chest infections. Caution and vigilance will lead to a good prognosis.

Isolated Persistent Left Superior Vena Cava with Continuation Into the Hemiazygos Vein and Left Renal Vein.

Isolated Persistent Left Superior Vena Cava with Continuation Into the Hemiazygos Vein and Left Renal Vein.

Variations in Azygos Venous System in The Eastern Indian Population: A Cadaveric Study

Background: This study aimed to classify Azygos vein patterns in the Eastern Indian population. Methods: During the routine dissection of MBBS in the 2018–2020 academic year, 20 formalin embalmed cadavers aged 50–70 were used to classify the azygos system. The cadaver’s age was verified by its entry into our institute’s anatomy register. The register confirmed that all cadavers used for dissection were of Indian origin. Though gender was not compared in this study, it was noted for record purposes by identifying the external genitalia and confirming it to the records. These were the exclusion criteria: 1) No major thoracic surgeries; 2) No major thoracic deformities. Azygos, hemiazygos, and accessory hemiazygos veins were also examined. Results: The Anson & McVay system was used to classify the recruited cadavers’ azygos system. The cadavers were classified into Type-1, Type-2, and Type-3. Type 2 was again subdivided into 5 subgroups and Type-3 into2 sub-groups. In one cadaver, Type-1 was observed, 17 cadavers had Type-2 azygos system, and 2 cadavers showed Type-3. Of the 17 cadavers of Type-2, 3 and 7 cadavers had Type-2A and -2B, respectively. Similarly, 4 and 1 cadavers had 2C and 2D patterns, respectively. Also, 2 cadavers showed 2E type. Of the 2 cadavers of Type-3, one was Type -3A and one Type-3B. The termination of the azygos vein vertebral level was between T2 and T4, of the hemiazygos vein was T8 to T11, and accessory hemiazygos veins were between T7 and T10. Conclusion: These variations should be well studied to avoid misinterpretation during radiological investigations and surgical interventions. KEY WORDS: Azygos vein, Hemiazygos vein, Posterior mediastinum, Radiological investigation, Variation.

Simultaneous IVC/SVC Endovascular Sharp Recanalization in A Patient with Budd-Chiari Syndrome, Systemic Lupus Erythematosus and Antiphospholipid Syndrome, A Case Report

Abstract:
 Background: Budd‐Chiari syndrome (BCS) is a rare life-threatening condition and is caused by an obstruction to the hepatic venous outflow. We herein report a case of BCS complicated with inferior vena cava (IVC) and superior vena cava (SVC) stenosis that was managed by a simultaneous IVC/SVC sharp recanalization.
 Case presentation: A forty-year-old lady came to the clinic complaining of distended abdomen. She is a known case of antiphospholipid syndrome and systemic lupus erythematosus. Triphasic liver computed tomography showed a heterogeneous liver with nutmeg appearance and attenuation of hepatic veins with caudate hypertrophy. There was a severe dilatation of the azygos and hemiazygos veins with multiple posterior mediastinal and retrocrural tortuous collaterals recanalizing the IVC distally. Contrast enhanced CT of the chest showed a chronic complete occlusion of the left brachiocephalic vein with enlargement of the left superior intercostal vein, hemiazygos, and azygos veins. SVC was patent with multiple calcific foci of the wall likely related to chronic thrombosis. Through the right femoral access, inferior venacavogram was obtained, which showed suprahepatic IVC complete occlusion. Then, an upper venous access was obtained through the right internal jugular vein. Followed by a venogram which showed a complete occlusion at the right brachiocephalic vein with extensive collaterals were noted. Sharp recanalization from the jugular access of the brachiocephalic vein/SVC was performed targeting the balloon within the SVC that was advanced from the azygos vein, which followed by placing a covered stent graft. Then Multiple balloon angioplasties were made at the level of suprahepatic IVC followed by placing a non-covered stent.
 Conclusion: It was a Successful recanalization for the completely occluded suprahepatic IVC and placement of IVC stent, and a Successful recanalization for the completely occluded right brachiocephalic vein and placement of a stent.

A unique presentation of anomalous posterior intercostal veins, hemiazygos vein and left superior vena cava

The venous anomalies of thorax are common, but the only drainage of 1st and 2nd posterior intercostal veins on both sides into the internal vertebral venous plexus with no communication to the azygos system is reported for the first time. The common hemiazygos vein is singular receiving all the posterior intercostal veins on the left from 4th to the 11th with subcostal on the left side. This vein drains into azygos on the right. It also connects on the cranial end via an anomalous vein to the Left SVC. This anomalous vein also receives the left 3rd posterior intercostal vein. On the right, the azygos system is normal.

Роль симпатичних стовбурів в іннервації кровоносних судин заднього середостіння у плодів людини

The purpose of the study was to establish patterns of variation of the branches of the right and left sympathetic trunks in the thoracic aorta azygos and hemiazygos veins during the fetal period of human ontogenesis. Materials and methods. An anatomical study was performed on 47 human fetuses using macromicroscopic preparation of neurovascular branches under the control of binocular magnifier, vascular injection, application contrasting of prepared vessels and nerves, making 3D reconstruction models of the posterior mediastinum structures and morphometry. Results. The anatomical variability of nodes and branches of the thoracic right and left sympathetic trunks involved in the innervation of the thoracic aorta, azygos and hemiazygos veins has been established in the human fetuses of different age groups. The segmental-metameric distribution of the visceral branches of the thoracic sympathetic trunk was revealed, as well as the preservation of the segmental sympathetic innervation of the thoracic aorta, azygos and hemiazygos veins both on the left and on the right. Despite the significant progress in the study of morphological features of innervation of posterior mediastinum organs and structures, the active development of fetal surgery in recent years raises a number of questions related to the sources of sympathetic innervation of the thoracic aorta, azygos and hemiazygos veins. Conclusion. The sources of innervation of the thoracic aorta, azygos and hemiazygos veins in human fetuses are: thoracic nodes and internodal branches of the right and left sympathetic trunks; large visceral nerves; branches of the esophageal, pulmonary and cardiac plexuses; vagosympathetic trunks; collateral trunk. The number of branches to the thoracic aorta from the left sympathetic trunk is 4-16, and from the right sympathetic trunk – 3-14. The largest number of branches that enter the wall of the thoracic aorta, from the left sympathetic trunk skeletotopically determined at the level of III-VI thoracic segments, and from the right sympathetic trunk – at the level of IV-VI thoracic segments. Different skeletotopic levels of the branches of the right and left large visceral nerves are involved in the innervation of the thoracic aorta – from V to X thoracic segments. It is noted that the right and left sympathetic trunks are almost equally involved in the innervation of the azygos and hemiazygos veins. The number of sympathetic branches to the azygos vein ranges from 4 to 7, and the number of sympathetic branches to the hemiazygos vein is usually 2-4

A rare case of left inferior vena cava presenting with May-Thurner syndrome

BackgroundMay–Thurner anomaly is characterized as external venous compression by the arterial framework against hard bony structures. This chronic anatomical lesion infrequently leads to deep vein thrombosis in the lower extremity, and it may lead to leg swelling as a long-term post-thrombotic complication. Left iliac vein compression may not be as uncommon as was previously thought, and it typically occurs in women more than men. Congenital anomalies of venous tree are not rare; they exist in 8.7% of the general population.Case-presentationWe herein present the first case of right-sided May Thurner Syndrome in a patient with IVC anomalies. In our patient, both common iliac veins formed the left-sided IVC, which extended to the hemiazygos vein and the superior vena cava. Additionally, there was a right-sided suprarenal IVC, which extended to the right atrium.ConclusionUnderstanding the proper anatomy in May-Thurner syndrome helps in better decision making for management of disease pathophysiology.

Systematic review of electrophysiology procedures in patients with obstruction of the inferior vena cava

AimsThe objective of the study was to conduct a systematic review to describe and compare the different approaches for performing cardiac electrophysiology (EP) procedures in patients with interrupted inferior vena cava (IVC) or equivalent entities causing IVC obstruction.MethodsWe conducted a structured search to identify manuscripts reporting EP procedures with interrupted IVC or IVC obstruction of any aetiology published up until August 2020. No restrictions were applied in the search strategy. We also included seven local cases that met inclusion criteria.ResultsThe analysis included 142 patients (mean age 48.9 years; 48% female) undergoing 143 procedures. Obstruction of the IVC was not known before the index procedure in 54% of patients. Congenital interruption of IVC was the most frequent cause (80%); and, associated congenital heart disease (CHD) was observed in 43% of patients in this setting. The superior approach for ablation was the most frequently used strategy (52%), followed by inferior approach via the azygos or hemiazygos vein (24%), transhepatic approach (14%), and retroaortic approach (10%). Electroanatomical mapping (58%), use of long sheaths (41%), intracardiac echocardiography (19%), transesophageal echocardiography (15%) and remote controlled magnetic navigation (13%) were used as adjuncts to aid performance. Ablation was successful in 135 of 140 procedures in which outcomes were reported. Major complications were only reported in patients undergoing AF ablation, including two patients with pericardial effusion, one of whom required surgical repair, and another patient who died after inadvertent entry into an undiagnosed atrioesophageal fistula from a previous procedure.ConclusionThe superior approach is most frequent approach for performing EP procedures in the setting of obstructed IVC. Transhepatic approach is a feasible alternative, and may provide a “familiar approach” for transseptal access when it is required. Adjunctive use of long sheaths, intravascular echocardiography, electro‐anatomical mapping and remote magnetic navigation may be helpful, especially if there is associated complex CHD. With careful planning, EP procedures can usually be successfully performed with a low risk of complications.

Atrial Embolization after a Transcatheter Mitral Valve Replacement

Atrial Embolization after a Transcatheter Mitral Valve Replacement

A case of esophageal atresia complicated by a right-sided aortic arch with right ductus arteriosus and inferior vena cava interruption with hemiazygos continuation

During the repair of esophageal atresia with tracheoesophageal fistula (EA/TEF), cardiovascular malformations occasionally create a technical challenge. We report a novel case of a 4-day-old girl with EA/TEF and multiple cardiovascular malformations, including right-sided aortic arch (RAA), right ductus arteriosus (RDA), single ventricle with single atrium, common atrioventricular valve, pulmonary atresia, bilateral superior vena cava, and interruption of the inferior vena cava (IVC) with hemiazygos continuation. In this case, a right-sided approach would require the mobilization of the RAA and RDA, which were supplying the pulmonary blood flow due to pulmonary atresia. Alternatively, the left-sided approach would require the mobilization of the hemiazygos vein, which was essential for venous return from the lower body due to IVC interruption. We performed the less intrusive left-sided approach, and the postoperative course was uneventful. Right-sided EA/TEF repair should be avoided because RDA spasm or injury caused by RAA mobilization would be fatal. In cases of interrupted IVC with azygos or hemiazygos vein continuation, care must be taken not to ligate these vessels or block the venous return. Preoperative evaluation is important to prevent complications in such complicated cases. If sufficient information is not available, the left-sided approach may be preferred. • In case of RAA with RDA, the EA/TEF repair should be approached from the left side. •Detection of cardiovascular malformations is necessary in case of EA/TEF with RAA. •This is the first case report of EA/TEF with RAA that clearly records RDA.

Transvenous lead implantation via the accessory hemiazygos vein in superior vena cava occlusion.

Occlusion of the superior vena cava (SVCO) hinders pacemaker and defibrillator lead delivery. Central venous stenosis or occlusion due to pacemaker or defibrillator leads is relatively common at the time of lead revision or device upgrade; however, complete occlusion occurs in less than 10%.1,2 Multiple implanted leads is associated with increased risk of developing SVCO.3 The presence of a persistent left superior vena cava (SVC) also complicates lead delivery and impacts lead stability; however, lead delivery is often still feasible.

Inferior vena cava thrombosis-rope ladder sign.

Congenital heart disease comprises one of the largest groups of congenital defects, affecting approximately 1% of births. Advances in pre- and postoperative critical care treatment as well as surgery and interventional procedures have improved survival rates, but treatment and long-term care of children with complex congenital heart disease remains challenging, and is associated with anumber of complications.Here, we report on a17-month-old infant with congenital univentricular heart disease who devloped post-operatively inferior vena cava (IVC) thrombosis. IVC thrombosis was confirmed by abedside contrast media study (X-ray) demonstrating collateral paravertebral circulation along the paravertebral sinuses bilaterally into the azygos and hemiazygos vein ("rope ladder sign"), with no contrast media detected in the IVC. The infant was subsequently started on aspirin and clopidogrel.