[Thoracoscopic resection of azygos vein aneurysm]. / Torakoskopicheskoe udalenie anevrizmy dugi neparnoi veny. Redkoe klinicheskoe nablyudenie.

Azygos vein aneurysm is a rare thoracic disease that often mimics posterior mediastinum tumors. Pathogenesis of azygos vein aneurysm is unclear. Discussions about possible causes are still ongoing. Most aneurysms are asymptomatic and diagnosed incidentally during standard examinations. Severe complications of azygos vein aneurysm include rupture with massive bleeding and pulmonary embolism. Contrast-enhanced chest CT and MRI are essential. Differential diagnosis includes tumors, cysts and rare neoplasms of the mediastinum. Treatment algorithm is not established. There are traditional surgical and endovascular methods. We present minimally invasive surgical treatment of azygos vein aneurysm in a 53-year-old woman. The patient underwent thoracoscopic resection of aneurysm. Histological examination revealed a partially thrombosed azygos vein aneurysm.

[Surgery for complicated accessory lobe of the azygos vein]. / Khirurgiya oslozhnennoi dobavochnoi doli neparnoi veny.

Congenital anomalies of respiratory system are quite diverse and not all of them are subject to surgical treatment. One example is accessory lobe of the azygos vein. This anomaly usually has no clinical manifestations and requires only follow-up, as well as attention in surgery on the right half of the chest for some other disease. This situation changes when complications occur, for example, purulent-inflammatory process. Therapy is not always effective, and lung tissue destruction requires surgical treatment. Progressive destruction complicates diagnosis and choosing surgical tactics. We present a rare case of severe purulent-inflammatory complication with abscess in accessory lobe of v. azygos. Anatomical abnormalities following this congenital pulmonary anomaly can cause difficulties in surgeries for other intra-thoracic diseases. The situation is especially relevant for thoracoscopic access. This report will be useful for radiologists, pulmonologists and thoracic surgeons.

Successful left ventricular lead placement by way of an azygos vein for a patient performing cardiac resynchronization therapy implantation with an occluded left subclavian vein: A case report.

Central venous obstruction following pacemaker implantation is not uncommon and can prove challenging in the case of a system upgrade to a cardiac resynchronization therapy pacemaker (CRT-P). We describe the case of a patient who underwent a successful upgrading procedure of a pacemaker to a CRT-P in the presence of an occluded left subclavian vein and superior vena cava, using collateral veins that drained into right atrium.

Computed tomography and magnetic resonance imaging of congenital thoracic systemic venous anomalies.

We present the imaging findings of thoracic systemic venous anomalies diagnosed by computed tomography and magnetic resonance imaging. Persistent left superior vena cava is the commonest anomaly of the thoracic systemic veins encountered either incidentally as an isolated finding or associated with congenital heart disease. Inferior vena cava (IVC) interruption with azygos continuation is the second most common anomaly, which may also be isolated or be associated with left isomerism syndrome. The article will also discuss other rarer systemic venous anomalies including retroaortic brachiocephalic vein and IVC drainage into the left atrium. Finally, the impact of pre-procedure reporting of thoracic systemic venous anomalies on the choice of intervention and patient outcome will be addressed.

Morphologic variations of the superior intercostal vein: An anatomical study with clinical applications.

This study aimed to validate and compare the anatomical variations of the superior intercostal veins, focusing on their origin, course, anastomoses, and destination. In addition, the results were compared with findings from other relevant studies. Fifty Korean and 16 Chinese adult cadavers were dissected for this study. The superior intercostal veins were dissected and measured. In our study of 66 specimens, the right superior intercostal vein was observed in 92.3% of cases, while the left superior intercostal vein was observed in 50%. The right superior intercostal vein was subdivided into six types based on its composition, which mainly drained the second and third right posterior intercostal veins. Similarly, the left superior intercostal vein was subdivided into eight types, primarily involving the second to fourth left posterior intercostal veins. This detailed anatomical study successfully identified and classified the various morphologic types of the superior intercostal vein and reviewed the clinical significance of this vein. The findings of this study can offer valuable anatomical evidence to physicians, aiding in their understanding and utilization of the superior intercostal vein.

A reappraisal of pediatric thoracic surface anatomy.

Accurate knowledge of surface anatomy is essential for physical examination, invasive procedures, and anatomy education. Individual factors such as age make surface landmarks variable so accurate descriptions are needed. The aim of this study is to describe age-related surface landmarks for intrathoracic structures in children. A total of 156 thoracic computed tomography scans of children aged 0-18 years were categorized into six groups, and the associations between major intrathoracic structures and surface landmarks were analyzed. Sternal angle is an accurate surface landmark for the azygos vein-superior vena cava junction in all age groups. However, the aortic arch (except in the 0-1 year group), the bifurcation of the pulmonary trunk and the tracheal bifurcation in those aged 15-18 years were not within this plane. The left brachiocephalic vein was located behind the ipsilateral sternoclavicular joint except in the 1-3 years group, and the right was behind it in children older than 6 years. The apex of heart was at the 5th intercostal space level in the 0-1 and 12-18 years groups; however, it was higher in the other groups. The lower borders of the lungs were at the sixth costal cartilage level in the midclavicular line, eighth intercostal space level in the midaxillary line, and T12 adjacent to the vertebral column in the 15-18 years group; the lower borders were at higher levels in younger children. Defining the variations in surface anatomy by in vivo studies will increase its clinical and pedagogical value.

Cadaveric dissection of connection between accessory hemiazygos vein and left brachiocephalic vein.

PURPOSE: The azygos system of veins has many anatomical variations that can impact mediastinal and vascular interventions. While radiological reports on these are of great clinical value, this study is among the first to present a high-quality cadaveric dissection of a rare anatomical variant to supplement previously published radiologic studies. The azygos venous system consists of the azygos vein (AV), hemiazygos vein (HAV), and the accessory hemiazygos vein (AHAV), which develop from the last portion of the posterior cardinal veins. The normal anatomical configuration includes drainage of the posterior intercostal veins, vertebral vein, esophageal veins, HAV, and AHAV to an unpaired right-side AV at the level of the 8th/9th thoracic vertebra. The reported incidence of AHAV draining directly into the left brachiocephalic vein is 1-2%. METHODS: An adult formalin-fixed 70-year-old female cadaver was dissected as part of a medical gross anatomy elective course. RESULTS: Gross documentation of a direct connection of the HAV to the AHAV with the AHAV draining into the left brachiocephalic vein. CONCLUSION: It is important to note the variations of the azygos system to avoid confusion with a potential pathology such as mediastinal masses. Understanding of the rare variant reported here could be useful in the prevention of iatrogenic bleeding from the misplacement of venous catheters and help facilitate radiological diagnosis in the incidence of venous clot formation.

The Dilemma of Balance between Benefits and Losses for Chondromyxoid Fibroma-like Osteosarcoma in Thoracic Spine with Azygos Tumor Thrombosis: A Case Report.

Background: Chondromyxoid fibroma-like osteosarcoma (CMF-OS) is an extremely rare subtype of osteosarcoma, its clinical data are scarce, and our understanding of it is far from sufficient. As it has few typical imaging manifestations, it is not uncommonly misdiagnosed clinically. Azygos vein thrombosis is also a rare entity, and there is a big controversy over treatments for it. Case presentation: Herein, we report a case of CMF-OS that occurred in the spine, coincidently, azygos vein thrombosis was found. A young male patient came to our clinic because of continuous back pain, and a neoplastic lesion was suspected in the thoracolumbar vertebrae. The pathological results of the biopsy showed a low grade of osteosarcoma, and chondromyxoid fibroma-like osteosarcoma was the primary diagnosis. Since the tumor cannot be en-bloc resected, he received palliative decompression surgery, followed by radio and chemotherapy. Azygos vein tumor thrombosis was not treated and, unfortunately, he died of heart failure caused by the thrombus migrating from the azygos vein to the right atrium. Before the palliative decompression surgery, both the patient and the clinical team were trapped in the dilemma of how big a surgery should be carried out to maximize the benefits of this patient. Results and complications: CMF-OS is indeed more aggressive than its pathological sections suggest. Guidelines for osteosarcoma should be followed. Furthermore, it is important to recognize the danger of tumor thrombosis in the azygos vein. Preventive measures have to be performed in a timely manner to avoid catastrophic results.

Impact of preservation of the azygos vein during surgical repair of esophageal atresia-tracheoesophageal fistula (EA-TEF): a systematic review and meta-analysis.

Esophageal atresia-tracheoesophageal fistula (EA-TEF) is one of the common congenital anomalies occurring in newborns. Over the last eight decades, various technical modifications have been proposed in the surgical repair of EA-TEF. Preservation of azygos vein is one such modification that has gained considerable attention. However, a consensus statement regarding the superiority of its preservation over its division is lacking. We aim to compare the outcomes of surgery between the two groups of newborns, i.e., those undergoing repair with and without azygos vein preservation, in terms of its complications. The authors systematically searched the databases PubMed, EMBASE, Web of Science, and Scopus through December 2020. The incidence of anastomotic complications and chest infection was compared among the two groups of newborns, i.e., those undergoing surgical repair with (group A) and without azygos vein preservation (group B). Statistical analysis was performed using a fixed-effects model, and pooled risk ratio (RR) and heterogeneity (I2) were calculated. The methodological quality of the studies was assessed using the Downs and Black scale. Six comparative studies, consisting of a total of 671 newborns, were included in the meta-analysis. As compared to group B, newborns belonging to group A showed a significantly lower incidence of pneumonitis in the postoperative period (RR 0.31; 95% CI 0.17-0.57, p = 0.0001). However, no significant difference in the incidence of anastomotic complications including anastomotic leak (RR 0.73; 95% CI 0.48-1.12, p = 0.15) and stricture (RR 0.63; 95% CI 0.36-1.09, p = 0.10) was observed between the two groups. The average Downs and Black scale scores ranged from 20 to 24. The risk of bias was low (n = 1) and moderate (n = 5) in the included studies. Kappa statistics showed a value of 0.902 (p < 0.001), highlighting an almost perfect agreement among the two observers. The present meta-analysis revealed the superiority of surgical repair of EA-TEF performed with preservation of azygos vein in terms of the incidence of postoperative chest infection. However, no significant difference in the occurrence of anastomotic leak and stricture was observed between the two groups. The level of evidence of the published comparative studies is limited. Therefore, well designed, randomized controlled trial utilizing a standardized operative approach on a larger sample-size needs to be conducted for optimal comparison between the two approaches.

Computed tomography angiography study of the azygos vein course and termination into superior vena cava: gender and age impact.

PURPOSE: The study highlights azygos vein (AV) topography, arrangement and confluence morphometry in dyspnoea and tachycardia patients of extrapulmonary and extracardiac aetiology. METHOD: Computed-tomography angiography of 25 male and 26 female patients (mean age 66.5 years) were studied for: thoracic vertebral (T) height of AV- superior vena cava-SVC confluence, AV course and deviations from vertebral column (VC) midline, AV and SVC diameters, distance (AV arch- lower border of carina) and gender and age impact. RESULTS: Commonest heights of the AV-SVC confluence were T5 (56.9%), T4 (31.4%), T6 (9.8%) and T3 (2%). The AV terminated into SVC after crossing the left side of VC midline in 56.9%, slightly deviated right of the midline in 37.3% and coursed right of VC in 5.9%. Mean AV and SVC diameters were 0.96 ± 0.18 cm and 1.86 ± 0.27 cm. Male predominance in AV and SVC diameters and a slight AV diameter significant increase with the age were found. The (AV highest point-lower border of carina) mean distance was 2.05 ± 0.44 cm and male predominance existed. CONCLUSION: The commonest termination height of the AV was T5, while T3 was the rarest one. Aging induces the AV leftward displacement, while gender had no impact. AV and SVC diameters had higher significant values in males, while ageing had a significant impact only in AV diameter. The AV higher diameters will be used as predictors for higher values of SVC diameter and mediastinum pathology. Such findings can be useful in mediastinal surgery, mediastinoscopy and surgery of VC deformations, neurovascular surgery of retroperitoneal organs, disc herniation and T fractures.

Cases of high lying azygos arch and its embryological consideration.

PURPOSE: This study aimed to report cases of high-lying azygos arch and discuss the embryological basis of its development by a thorough evaluation of the anatomical features assessed using computed tomography (CT) images. METHODS: This study was approved by our institutional review board. We retrospectively reviewed chest CT images between November 2011 and November 2018. To determine high-lying azygos arch, we set the upper margin of the T4 vertebral body as the reference level. Regarding the embryological development of high-lying azygos arch, we retrospectively reviewed the CT images of 105 patients with tracheal bronchus to identify the location of the azygos arch. RESULTS: We noted that on three cases CT images, the azygos arch was located higher than the upper margin of the right main bronchus, and drained into the proximal superior vena cava (SVC) at a level higher than the conventional T4 or T5 vertebral level. All 105 patients with right tracheal bronchus showed azygos arch above the tracheal bronchus. CONCLUSION: This variation in the location of the azygos arch can mimic pathological lesion on plain radiographs, and, therefore, it is important to be aware of high-lying azygos arch. Our findings show that the azygos arch may have possibly migrated downward during embryological development.

Minimally invasive esophagectomy: Preservation of arch of Azygos vein in prone position.

Minimally invasive esophagectomy (MIE) for oesophageal cancer has gained wide popularity in recent years due to its improved morbidity and mortality outcomes. We describe our modified technique of MIE in prone position with preservation of the arch of azygos vein. In our experience with 14 patients, the mean operative duration was 378 min (standard deviation [SD] 378 ± 59 min) and the mean blood loss was 390 ml (SD 390 ± 142 ml). The mean lymph node count was 28 (range 17-54). The Visick score was I in 12 (85.7%) patients and II in 2 (14.3%) patients at follow-up. The preservation of azygos vein arch is a technically feasible procedure and may be associated with a better quality of life outcome.

Thoracoscopic oesophago-oesophagostomy in the prone position for oesophageal stenosis caused by dilated azygos vein in polysplenia-associated heterotaxy.

BACKGROUND: Heterotaxy syndrome is associated with a plethora of cardiovascular and other multi-system anomalies with a high childhood mortality. A dilated azygos vein as part of the polysplenia variant of heterotaxy syndrome may cause oesophageal stenosis owing to a prolonged compression. We describe our technique of extramediastinal oesophago-oesophagostomy in the prone position for this rare congenital syndromic malformation with an excellent outcome. PATIENTS AND METHODS: A 17-year-old boy with heterotaxy syndrome presented with intermittent dysphagia and postprandial emesis with failure to thrive. Despite the presence of diverse anatomic abnormalities, it was only his symptom of dysphagia due to oesophageal stricture that merited surgical intervention. He underwent an azygos-preserving extramediastinal oesophago-oesophagostomy in the prone position without segmental resection with the establishment of continuity using a modified Collard-type anastomosis. RESULTS: The patient had an uneventful convalescence, with imaging after 1 year showing no re-stenosis. After a follow-up of 3 years, the patient is free of symptoms and has gained weight. CONCLUSION: Oesophageal stenosis may result from prolonged compression by anomalous vasculature. An isolated correctable anatomic derangement, young age with good functional reserve, other associated anomalies not causing any symptoms, the physiological advantages of executing the surgery in a prone position and availability of expertise in minimally invasive surgery ensured excellent outcomes. The hitherto unreported technique may open up avenues for further research regarding the behaviour of the oesophageal muscular tube with transection and re-anastomosis for rare benign abnormalities.

Hemodynamic changes in women with symptoms of supine hypotensive syndrome.

INTRODUCTION: Supine positioning during late pregnancy causes the gravid uterus to compress the inferior vena cava, resulting in dramatic hemodynamic changes. The maintenance of placental perfusion requires maternal circulatory and autonomic adaptations. Women with supine hypotensive syndrome (defined as a drop in systolic blood pressure of anything between 15 and 30 mmHg or an increase in heart rate of 20 bpm, with or without symptoms) may have reduced ability to compensate for the effects of supine positioning. MATERIAL AND METHODS: Twelve women with uncomplicated pregnancies and no symptoms of supine hypotension (normal) and 10 women with uncomplicated pregnancies who reported symptoms of supine hypotension between 34 and 38 weeks' gestation underwent magnetic resonance imaging in the supine and left lateral positions. Phase contrast images were evaluated to measure blood flow through the aorta, inferior vena cava, superior vena cava and azygos vein. RESULTS: Women with symptoms of supine hypotension showed significant reductions in azygos venous flow rate compared with the normal group (-0.15 (-0.30 to -0.01) L/min). Those with symptoms showed no statistically significant compensatory changes in heart rate compared with the normal group (heart rate change 4.5 (-3.1 to 12.1) bpm). Hemodynamic changes in response to positioning were similar across both groups including: a reduction in inferior vena cava blood flow, reduction in cardiac output and an increase in azygos blood flow. CONCLUSIONS: Maternal hemodynamic adaptations were found to be consistent across groups irrespective of whether the women had symptoms of supine hypotension. In both groups a reduction in blood flow through the inferior vena cava occurred in the supine position with a subsequent reduction in cardiac output. Both groups showed a compensatory increase in blood flow through the azygos vein in order to partially compensate for this. Taking into account the effect of maternal position, women with symptoms were found to have reduced azygos flow compared with asymptomatic women. There was a significant increase in heart rate when the women were supine than when they were in the left lateral position.

The effect of positioning on maternal anatomy and hemodynamics during late pregnancy.

INTRODUCTION: Supine positioning during late pregnancy causes dramatic compression of maternal abdominal vasculature and is a risk factor for stillbirth. The azygos vein has been shown to provide collateral circulation in this scenario. There are many well-known anatomical differences in abdominal vasculature between the left and right sides of the body. However, the effect of left and right positioning in pregnancy has not been well studied. MATERIALS AND METHODS: After obtaining ethics approval, 10 women with uncomplicated pregnancies between 34 and 38 weeks gestation underwent magnetic resonance imaging in the left and right lateral positions. Phase contrast images were evaluated to measure blood flow through the abdominal aorta, inferior vena cava, and azygos vein. RESULTS: No significant differences between left and right lateral positions were found in blood flow through the IVC at its formation (mean difference -0.15 L/min [CI -0.47, 0.18], p = .34) or through the azygos vein (mean difference 0.02 L/min [CI -0.22, 0.26], p = .87). Blood flow through the IVC just above the level of the renal veins was found to be reduced by 35% in the right lateral position when compared to the left (mean difference 1.01 L/min [CI 0.25, 1.43], p = .03). There were no significant differences in cardiac output or blood flow through the abdominal aorta. CONCLUSIONS: While it was noted that blood flow through the IVC immediately above the level of the renal veins was reduced in the right lateral position, this did not appear to impact significantly on maternal cardiac output or blood flow through the azygos vein.

Transposition and variant termination of azygos and hemiazygos veins: an extremely rare variation.

Azygos system of veins is the main source of venous drainage from the thoracic wall. Knowledge of azygos vein anomalies could be of importance to cardiothoracic surgeons and radiologists. We report a rare variation of azygos vein as seen in an adult male cadaver aged 65 years approximately. The azygos vein was formed by the union of left ascending lumbar and subcostal veins. It coursed upwards on the left side of descending thoracic aorta and crossed the left subclavian artery and the left vagus to terminate into the left brachiocephalic vein. It received left superior intercostal vein and left fifth to eleventh posterior intercostal veins. The hemiazygos and accessory hemiazygos veins were situated on the right side of the vertebral column. They received the right posterior intercostal veins and terminated into the azygos vein at the level of eighth thoracic vertebra.

Misplacement of Tunneled Hemodialysis Catheter into Azygos Vein: Left or Right Jugular Insertion Has Similar Susceptibility.

BACKGROUND: Central venous catheter (CVC) is commonly used to provide access for hemodialysis (HD) when arteriovenous access is not available. The misplacement of CVC into azygos vein (AV) is a rare but a potential serious complication. Previous reports communicated the opinion that left-sided catheterization predisposed to AV misplacement, but these reports concentrated on peripherally inserted CVCs, placed for indications rather than HD. Unintended AV misplacement of HD catheters (HDCs) has not been well studied. We seek to investigate factors associated with inadvertent AV miscannulation during HDC placement. METHODS: We are to present a case of unintentional misplacement of a tunneled HD catheter (tHDC) into the azygos arch from right internal jugular vein (RIJV) despite real-time fluoroscopy guidance. Additionally, we have undertaken a systematic literature search in Pubmed to study the anatomical and other factors related to unintended AV misposition in HD setting. RESULTS: From 2005 to August 31, 2018, a total of 11 articles containing 16 cases of misplacement of HDCs into AV were identified. Of the 17 cases of unintentional AV misposition including ours, the majority of the misguided HDCs (94.1%, 16/17) were tHDCs and only 1 case was related to a temporary (non-tunneled) catheter. Most catheter misplacements (88.2%, 15/17) were performed without real-time radiological guidance. The reported incidence of inadvertent AV cannulation from different institutions varied between 0.6% and 3.8%. Among the 16 misplaced tHDCs, the rates of AV misposition that arose from RIJV and left internal jugular vein (LIJV) insertion are even at 50%. CONCLUSIONS: Based upon anatomical and case studies, we have found that AV may join posterior aspect of superior vena cava at different directions and levels. Hence, this might explain why AV misplacement might occur whether an HDC is inserted from the LIJV or RIJV approach. By raising the awareness of this potential complication and how we may minimize it, we hope to reduce the future complication of AV misposition.

What is the history of the term "azygos vein" in the anatomical terminology?

The term "azygos vein" is in common use in modern anatomical and cardiovascular textbooks to describe the vein which ascends to the right side of the vertebral column in the region of the posterior mediastinum draining into the superior vena cava. "Azygos" in Greek means "without a pair", explaining the lack of a similar vein on the left side of the vertebral column in the region of the thorax. The term "azygos" vein was utilized firstly by Galen and then was regenerated during Sylvius' dissections and Vesalius' anatomical research, where it received its final concept as an official anatomical term. The purpose of this study is to highlight the origin of the term "azygos vein" to the best of our knowledge for the first time and its evolution from the era of Hippocrates to Realdo Colombo.

[Characteristics and prognosis of interrupted inferior vena cava with azygous continuation].

Objective: To explore the clinical characteristics of interrupted of the inferior vena cava with azygous continuation and the prognosis. Methods: Retrospective analysis of 21 fetuses diagnosed with interrupted inferior vena cava with azygous continuation among 28 567 pregnant women who underwent routine ultrasound scan. The clinical data, ultrasonographic features, genetic information and prognosis were collected. Results: Interrupted of the inferior vena cava with azygous continuation occurred in 21(0.07%, 21/28 567) of 28 567 patients. Three fetuses (14%, 3/21) complicated with heart and extracardiac malformations, including endocardiac cushion defect, single atrium and single ventricle, double superior vena cava, dextrocardia, asplenia syndrome, visceral heterotaxy, duodenal atresia; six fetuses (29%, 6/21) were associated with cardiac anomalies, such as hypoplastic left heart syndrome, double outlet right ventricle, pulmonary stenosis, ventricular septal defect, persistent left superior vena cava, endocardiac cushion defect and transposition of the great arteries; six cases (29%, 6/21) were only combined with extracardiac malformations, includingasplenia syndrome, visceral heterotaxy, duodenal atresia. Three fetuses (14%, 3/21) were nonorganic abnormalities included thickening of the right ventricle wall, fetal bradycardia, pericardial effusion, hydrops abdominis, increased peak systolic velocity/end diastolic velocity and single umbilical artery. Three fetuses (14%, 3/21) were isolated interrupted inferior vena cava with azygous continuation, but without other anomalies and 2 of them had normal fetal karyotype. Five cases (24%, 5/21) were successfully vaginal delivery, 1 case (5%, 1/21) had cesarean section. After 12-40 months follow-up, we didn't obeserve obviously abnormality, nor any chromosomal abnormality. Ten patients (48%, 10/21) opted for termination of the pregnancy and the autopsies were not done. Five cases (24%, 5/21) were lost to follow up. Conclusions: Interrupted inferior vena cava with azygous continuation are associated with cardiovascular and extracardiac anomalies, cardiac malformation and visceral heterotaxy are the most common anomalies. Visceral heterotaxy should be considered and fetal karyotype should be suggested. In the cases of isolated interrupted inferior vena cava with azygous continuation and normal karyotype, the outcome is favorable.