Clinical significance of azygos vein enlargement: radiographic recognition and etiologic analysis

Transient Ischemic Attack, the Initial Presentation of Azygos to Pulmonary Vein Fistula

There are different sources of cerebral emboli, including cardiac embolism, extracranial arterial embolism, paradoxical embolism, trauma, and iatrogenic embolism. In rare cases, atypical sources should be ruled out. We are reporting a lady who presented with transient ischemic attack and had a fistula between the azygos to the pulmonary vein. (Level of Difficulty: Advanced.).

Azygos Vein Enlargement Secondary to Superior Vena Cava Syndrome on 18F-FDG PET/CT

ABSTRACT

Obstruction of the blood flow from the superior vena cava (SVC) to the right atrium causes the SVC syndrome. The azygos system is the most important way to overcome SVC obstruction. Azygos vein enlargement can be seen secondary to the SVC syndrome. Although a few cases showing 18F-FDG uptake along the SVC in SVC syndrome were reported before, 18F-FDG PET/CT findings of azygos vein enlargement have not been documented yet. Herein, we presented an intriguing case of azygos vein enlargement secondary to SVC syndrome on 18F-FDG PET/CT.

The Azygos Vein From A to Z

Congenital and acquired abnormalities of the azygos vein can affect its size and position. Alteration of contrast material flow dynamics of the azygos vein on computed tomography can be an indication of superior vena cava obstruction. Recognition and accurate characterization of abnormalities of the azygos vein on imaging studies is critical to facilitate prompt diagnosis and direct workup when necessary. The main purpose of this article is to illustrate and describe the radiologic features of various congenital and acquired abnormalities affecting the azygos venous system.

Successful Extracorporeal Membrane Oxygenation After Incidental Azygos Vein Cannulation in a Neonate With Right-Sided Congenital Diaphragmatic Hernia Interruption of the Inferior Vena Cava and Azygos Continuation

Incidental azygos vein cannulation has been reported in a few cases of neonatal extracorporeal membrane oxygenation (ECMO). This complication is described in the literature mainly in pathological conditions wherein increased central venous pressure dilates the superior vena cava (SVC), i.e., right congenital diaphragmatic hernia (CDH) or pulmonary hypertension. Azygos vein cannulation should always be suspected in cases of impaired venous return and circuit failure. Although rare, it hinders proper venous aspiration of the ECMO circuit and generally requires repositioning or replacement of the venous cannula or conversion to central cannulation. In this report, we describe a newborn with severe right CDH who required ECMO assistance, wherein incidental cannulation of the azygos vein resulted in successful functioning of the circuit because of the concomitant presence of isolated interruption of the inferior vena cava and azygos continuation. To the best of our knowledge, this is the first report of successful neonatal ECMO despite azygos vein cannulation in a patient with such rare physiology.

Radiological features of azygos and hemiazygos continuation of inferior vena cava: A case report

RATIONALE

Azygos and hemiazygos continuation of the inferior vena cava (IVC) is uncommon. It is rare especially when it is not associated with congenital heart disease or deep venous thrombosis.

PATIENT CONCERNS

We report an interesting case of an interstitial lung disease with an interrupted IVC with azygous and hemiazygos continuation. A 67-year-old man suffered from cough and shortness of breath.

DIAGNOSES

Computed tomography revealed absence of the hepatic segment of the IVC with azygos and hemiazygos continuation. The patient did not have congenital anomalies of the remaining thoracoabdominal vasculature and viscera. The diagnosis of azygos and hemiazygos continuation of IVC was made by inferior venacavography.

INTERVENTIONS

There was no significant association between interstitial lung disease and expanded azygos and hemiazygos veins. The patient was treated with corticosteroids.

OUTCOMES

After 6 months of follow-up, the patient was asymptomatic.

LESSONS

It is important to recognize the enlarged azygos vein at the confluence with the superior vena cava and in the retrocrural space to avoid misdiagnosis as a right-sided paratracheal mass or retrocrural adenopathy.

Imaging the posterior mediastinum: a multimodality approach

The posterior mediastinum contains several structures that can produce a wide variety of pathologic conditions. Descending thoracic aorta, esophagus, azygos and hemiazygos veins, thoracic duct, lymph nodes, adipose tissue, and nerves are all located in this anatomical region and can produce diverse abnormalities. Although chest radiography may detect many of these pathologic conditions, computed tomography and magnetic resonance are the imaging modalities of choice for further defining the relationship of posterior mediastinal lesions to neighboring structures and showing specific imaging features that narrow the differential diagnosis. This review emphasizes modality-related answers to morphologic questions, which provide precise diagnostic information.

Ivor Lewis esophagectomy in a patient with enlarged azygos vein: a lesson to learn

We report the case of a 62-year-old patient with congenital interruption of the inferior vena cava and azygos continuation who required transthoracic esophagectomy to remove a tumor in the middle esophagus. The consequences of dividing an enlarged azygos vein in this kind of patient are reported and discussed.

Ultrasonography of the Retrocrural Region Normal and Pathological Findings

This pictorial essay illustrates normal and pathological findings in the region posterior to the diaphragmatic crura as demonstrated on ultrasound scans. Familiarity with the spectrum of normal and abnormal findings in this region will increase the diagnostic power of ultrasound scans of the upper abdomen.

Enucleation of Esophageal Leiomyoma with Azygos Continuation of the Inferior Vena Cava: Report of a Case

We herein report a rare case of esophageal leiomyoma in an 18-year-old woman with azygos continuation of the inferior vena cava. A submucosal tumor was located in the left wall of the esophagus behind the carina. The enlarged azygos vein made video-assisted thoracic surgery so difficult that conversion to a minithoracotomy and transection of the right superior intercostal vein were necessary to fully visualize the tumor. A pathological diagnosis revealed leiomyoma. Our experience suggests that a transection of the right superior intercostal vein is effective for the proper exposure of an esophageal tumor located behind the carina in a patient with an enlarged azygos vein.

Diagnostic techniques in assessing vessels of the gastrointestinal tract

Vascular disorders of the gastrointestinal tract include a variety of different underlying diseases, thus requiring different and, in many cases, more than one imaging procedure. Only a knowledge of the newest developments in vascular imaging techniques with all the possibilities and limits will ensure a time- and cost-effective, accurate and reliable diagnosis. In many acute cases and also as a screening procedure, ultrasound in combination with colour Doppler and duplex sonography, plays an important role in setting the right course for further imaging techniques, and can provide the correct diagnosis in many cases.Depending on the most prominent symptoms and the expected disease, the right choice of technique saves valuable time. Computed tomography (CT) and magnetic resonance imaging (MRI) are cross-sectional imaging techniques that not only demonstrate lesion vascularization, but also provide information about neighbouring structures and complications in an understandable and demonstrable way. The use of angiography as an invasive tool should be limited to cases where a high temporal and spatial resolution is necessary to make the diagnosis or where therapeutic interventions are also likely to be performed within the same setting. For the diagnosis of gastrointestinal vascular diseases, often no generally valid recommendation can be given, since the impact of all imaging techniques will depend on the examiner's experience, the technical equipment and on their 24-h availability in a hospital. This chapter tries to give some information about the inherent limits and indications of the different imaging techniques, as well as the newest study results concerning the most frequent vascular diseases of the gastrointestinal tract.