A revamped MIC-McKeown operation without removing azygos vein arch, bronchial artery and vagus nerve trunk

BACKGROUND

The purpose of this study was to investigate the effect of our revamped MIE-McKeown operation on postoperative gastrointestinal function recovery.

METHODS

This revamped MIE-McKeown operation without removing azygos vein arch, bronchial artery and vagus nerve trunk and with the tubular stomach buried throughout esophageal bed and azygos arch, has been implemented from July 2020 to July 2021 by the same medical team of Gaozhou People's Hospital thoracic surgery for 13 times. Preoperative clinical data, main intraoperative indicators and postoperative complications were observed.

RESULTS

All patients had esophageal malignant tumors at the level of middle and lower thoracic non-azygous venous arch, with preoperative clinical stage CT1-2N0M0 stage i-ii. V-vst test was performed on the 7th postoperative day, and 10 patients were found to have no loss of safety/efficacy. There were 2 cases with impaired efficacy and no impaired safety, 1 case with impaired safety. There were 1 cases of pulmonary infection, 1 cases of anastomotic fistula combined with pleural and gastric fistula, 2 cases of hoarseness, 2 cases of arrhythmia, 10 cases of swallowing function were grade i, 2 cases of swallowing function were grade iii, 1 case of swallowing function was grade iv in watian drinking water test one month after operation.

CONCLUSIONS

Merit of this revamped MIE-McKeown operation is well preserving the integrity of azygos arch of vagus nerve and bronchial artery, and it is technically safe and feasible. No postoperative mechanical obstruction of thoracostomach, huge thoracostomach and gastrointestinal dysfunction occurs.

Double superior venae cavae with absence of the coronary sinus and anomalies of the azygos venous system

The superior vena cava is formed during the fetal period by the development of anastomoses between the right and left anterior cardinal veins, and the regression of the central part of the left anterior cardinal vein. The persistence of this part of the left anterior cardinal vein causes the formation of a left superior vena cava, which is a rare anomaly in cadaver dissection. We report the case of a persistent left superior vena cava with a normal right superior vena cava in a 95-year-old male cadaver, which was discovered during anatomical dissection for medical students at Kawasaki Medical School in 2016. The left superior vena cava was formed by the confluence of the left internal jugular and left subclavian veins and terminated in the right atrium via what would normally be the coronary sinus. The right and left superior venae cavae received intercostal veins via a right and left azygos vein, respectively. However, the right azygos vein was shorter than the normal azygos vein and received only the second to fifth intercostal veins, whereas the left azygos vein received the fifth to eleventh left intercostal veins and the sixth to eleventh right intercostal veins. We consider that the anomalies of the azygos venous system were the result of regression of right supracardinal vein and the persistence of the left supracardinal vein during development. An awareness of such variations of major thoracic veins is important for the interpretation of unusual CT images.

Atrial flutter ablation by femoral approach in a woman with azygos continuation of an interrupted inferior vena cava and dual chamber pacemaker

This report describes a case of isthmus-dependent atrial flutter ablation by the femoral approach in a 54-year-old woman with a previously unknown absence of the inferior vena cava (IVC) and dual chamber pacemaker. Despite looping of the catheters, ablation and termination of atrial flutter were performed successfully without function alteration of the pacemaker leads.  This is the first report of an inferior-to-superior approach for ablation of atrial flutter in the absence of the perihepatic IVC with the presence of chronic indwelling leads in the area targeted for radiofrequency.

Successful Pancreatic Duct Stent Placement for Recurrent Pancreatitis in a Patient with Polysplenia with Agenesis of the Dorsal Pancreas and Peutz-Jeghers Syndrome

A 52-year-old woman presented with relapsing acute pancreatitis. A contrast CT scan revealed polysplenia, agenesis of the dorsal pancreas, preduodenal portal vein, inferior vena cava with persistent continuity of the azygos vein, abnormal lung lobation with bilateral left bronchial morphology, and intestinal malrotation (non-rotation type). To the best of our knowledge, this is the first report in which successful pancreatic duct stent placement for the treatment of recurrent pancreatitis was performed in a polysplenia patient with agenesis of the dorsal pancreas, separate bile and pancreatic ducts and Peutz-Jeghers syndrome.

Paradoxical arterial hypoxemia in a left-to-right shunt congenital heart disease

The hepatopulmonary syndrome is a rare complication of different types of chronic hepatic diseases with associated portal venous hypertension, resulting in pulmonary vascular dilatation, predominantly in the lower lung fields, and leading to ventilation-perfusion mismatch, arterial hypoxemia and a poor prognosis. We present the case of 42-year-old male patient with an anomalous drainage of the right superior pulmonary vein into the azygos vein and a portal vein cavernomatosis with associated portal venous hypertension who presented severe oxygen desaturation, during exercise, in the context of a hepatopulmonary syndrome.

[Surgical resection of a pulmonary pleomorphic carcinoma involving the azygos vein]

We report a case of surgical treatment of pulmonary pleomorphic carcinoma invading the azygos vein. Chest computed tomography (CT) revealed a mass of 6 cm in size, in the upper lobe of the right lung. He underwent the right upper lobectomy and lymph node dissection with combined resection of the involved azygos vein. Histological examination revealed pleomorphic carcinoma (pT3N0M0, stage IIB). The postoperative course was uneventful, and he was alive without recurrence 26 months after the operation. Six cases of pleomorphic carcinoma have been surgically treated between June 2008 and August 2009 in our institute. Early diagnose with complete resection is suggested to be essential in the improvement of survival for this disease based on review of our experience.

Leg ulceration in chronic venous insufficiency caused by an absent inferior vena cava

We report here the case of a 55-year-old Japanese man with a one-year history of multiple ulcers on the left crural region. He had had pronounced varicose veins on both legs and the abdominal region for 35 years. Computed tomography images of the thoracic and abdominal regions showed the absence of an inferior vena cava, with pronounced dilatation of paravertebral venous plexus, cutaneous and azygous veins. Conservative topical treatments led to complete healing of the ulcers in one month. An absent inferior vena cava is an uncommon abnormality, often complicated by cardiac and other visceral malformations. It is a rare cause of chronic leg ulcers.

Double superior vena cava presenting with anomalous jugular and azygous venous systems

OBJECTIVE

To report on the double superior vena cava occurring with anomalous azygous vein and abnormal termination of the cardiac veins, which has not been reported before in one individual.

RESULTS

Examination of the heart revealed the presence of both the right and left superior vena cava. The right superior vena cava terminated into the right atrium and received the right root of the azygous vein, and the left superior vena cava received the left root of the azygous vein before entering the dilated coronary sinus. The azygous vein ascended in the right chest, and at the level of the third thoracic vertebra, it divided into the right and left roots, which joined the respective superior vena cava. Observation of the left lung revealed the presence of both the oblique and horizontal fissures that demarcated the upper, middle, and lower lobes. Dissection of the neck revealed abnormal connection of the superficial veins. The left external and anterior jugular veins opened at the confluence of veins that was drained by the venous arch that passed to the right side of the neck to open into the right external jugular vein.

CONCLUSION

The coexistence of double superior vena cava with azygous and superficial jugular venous anomalies is considered to be incidental finding. However, continued documentation of such anomalies is clinically important, and it remains to be important in medical science.

Combined Scimitar syndrome and interruption of the inferior vena cava causing mega-azygous and hemiazygous veins

Computed tomography angiography detected scimitar syndrome with venous drainage to the inferior vena cava caudal to an interruption of the inferior vena cava in a 48-year-old woman. The hepatic veins drained to the supra-hepatic portion of the inferior vena cava cephalic to the interruption, which was a short area of atresia. Azygous and hemiazygous veins were massively enlarged since they drained the right lung, abdomen viscera exclusive of the liver and lower extremities. Inferior vena cava interruption by a short, focal atresia has not previously been described. The inferior vena cava immediately caudal to the interruption is presumed to remain patent because of the scimitar vein flow.

A case of multiple abnormalities of the azygos venous system: a praeaortic interazygos vein

The posterior thoracic wall, an area drained by the azygos venous system, is a common site for surgical intervention. Since the venous part of the cardiovascular system is subject to most common variation, abnormalities in the azygos venous system are often reported. Some of the anatomical variants have significant clinical implications for computed tomography image assessment and mediastinal surgery. During dissection of the posterior mediastinum in a 76 year-old Caucasian male cadaver we found a rare variation in the azygos venous system. The hemiazygos vein drained the left 9th to 11th left posterior intercostal veins. While passing ventrally to the aorta at the level of the body of the eighth thoracic vertebra it was joined by two separate vessels found to be the continuations of the 7th and 8th left posterior intercostal veins. The resultant dilated vessel, termed the "interazygos vein", then opened into the azygos vein on the right side of the vertebral column. Variation in the azygos venous system has often been reported, but the abnormality observed by us appears to be extremely rare. The interazygos vein passing ventrally to the aorta may mimic enlarged lymph nodes and cause misinterpretation of a computed tomography image or, if accidentally damaged during mediastinal surgery, may lead to intraoperative haemorrhage. To the best of our knowledge this report provides new data of potential clinical significance.

Pseudotumoral azygos and paraesophageal varices of posterior mediastinum in a 15-month-old infant: a case report

A case of azygos and paraesophageal varices presenting as a posterior mediastinal mass in a 15-month-old infant with biliary atresia is described. The patient was evaluated for living donor liver transplantation because of repeated cholangitis after Kasai operation, and plain CT scan demonstrated a mass in posterior mediastinum. The operation of mediastinal tumor resection was planned before liver transplantation in order to exclude malignant disease, however, possibility of paraesophageal varices remained. Contrast-enhanced magnetic resonance imaging clearly demonstrated azygos and paraesophageal varices in posterior mediastinum. Living donor liver transplantation was performed successfully without ligation of paraesophagogastric varices. Contrast-enhanced CT demonstrated distinctly decreased mediastinal mass one month after transplantation.

Pitfall in pediatric dialysis: malposition of a dialysis catheter mimicking azygos continuation syndrome

Central venous catheters are established as vascular access in hemodialysis therapy. Vascular catheter misdirection may occur and is a well known problem. We present a rare catheter malposition in a young dialysis patient with consequent dilatation of the azygos vein system, simulating the appearance of an azygos continuation syndrome.

Venous hemangioma of the azygos arch

Giant venous hemangiomas of the azygos arch are exceedingly rare and idiopathic. To the best of our knowledge, there have been only two reports of azygos hemangioma. We report a case of hemangioma of azygos arch in a 46-year-old man after a complete resection and discuss the strategy that was used for the diagnosis and therapy.

Isolated interrupted inferior vena cava with azygos continuation mimicking paraesophageal lymph node enlargement

We report a case of interrupted inferior vena cava with azygos continuation diagnosed as a isolated finding in a patient with lung carcinoma. Findings of the unopacified CT scan initially simulated a paraesophageal lymphadenopathy. The contrast-enhanced spiral CT scan showed a dilated azygos vein in the absence of definable inferior vena cava.

[Heterotaxia syndrome without congenital cardiac defects in dilated cardiomyopathy]

HISTORY AND OUTPATIENT INVESTIGATION: A 61-year-old woman presented with a six-month history of chest pain and shortness of breath on normal activity. The past medical history included hypertension treated with ACE inhibitors. While still an outpatient a diagnosis was made of cardiomyopathy with left atrial and ventricular dilatation, systolic and diastolic heart failure, moderate mitral valve regurgitation and newly documented atrial fibrillation.

INVESTIGATION

Right heart catheterization was carried out via the right femoral vein. The inferior vena cava was found to be on the left, none on the right. Venous inflow was via a dilated hemiazygos vein, a persistent left superior vena cava and a markedly dilated coronary sinus into the right atrium. The hepatic veins were also directly connected to the right atrium, as was shown by retrograde perfusion during a venogram. Coronary heart disease was excluded by angiography, but a right heart catheterization was not possible because of the atypical venous connections. Ultrasound examination revealed abdominal situs inversus and polysplenia. Magnetic resonance imaging of the thorax demonstrated bilateral bilobar lungs and bilateral hyparterial bronchi.

DIAGNOSIS, TREATMENT AND COURSE

Heterotaxia with anomalous systemic veins and visceral defects was revealed during a diagnostic work-up, which was indicated by the finding of a dilated cardiomyopathy with chronic atrial fibrillation, moderate mitral valve regurgitation and arterial hypertension. Arterial hypertension and heart failure were successfully treated by medication. Attempts at rhythm control were unsuccessful. Safety measures were established to prevent thromboembolic complications and endocarditis.

CONCLUSION

Congenital anomalies of the systemic veins in adults are often discovered incidentally, because they are usually asymptomatic. They may cause diagnostic and therapeutic difficulties in cardiology, phlebology and surgery. These anomalies may increase the risk of thrombotic and thrombembolic events. Together with polysplenia and situs inversus they are phenotypical components of heterotaxia. They may have various clinical consequences and may occur spontaneously or may be familial.

[A pitfall of transseptal catheterisation for percutaneous mitral commissurotomy: interruption of the inferior vena cava with azygos continuation]

Transseptal catheterisation is a widely used technique in interventional cardiology. The authors report the case of a 37 year old woman admitted for percutaneous mitral commissurotomy of a symptomatic rheumatic mitral stenosis in whom transseptal catheterisation was impossible because of a rare congenital anomaly: interruption of the inferior vena cava with azygos vein continuation.

Evaluation of the effects of combined endoscopic variceal ligation and splenectomy with pericardial devascularization on esophageal varices

AIM: To detect the hemodynamic alterations in collateral circulation before and after combined endoscopic variceal ligation (EVL) and splenectomy with pericardial devascularization by ultrasonography, and to evaluate their effect using hemodynamic parameters.

METHODS: Forty-three patients with esophageal varices received combined EVL and splenectomy with pericardial devascularization for variceal eradication. The esophageal vein structures and azygos blood flow (AZBF) were detected by endoscopic ultrasonography and color Doppler ultrasound. The recurrence and rebleeding of esophageal varices were followed up.

RESULTS: Patients with moderate or severe varices in the esophageal wall and those with severe peri-esophageal collateral vein varices had improvements after treatment, while the percentage of patients with severe para-esophageal collateral vein varices decreased from 54.49% to 2.33%, and the percentage of patients with detectable perforating veins decreased from 79.07% to 4.65% (P < 0.01). Color Doppler flowmetry showed a significant decrease both in AZBF (43.00%, P < 0.05) and in diameter of the azygos vein (28.85%, P < 0.05), while the blood flow rate was unchanged. The recurrence rate of esophageal varices was 2.5% (1/40, mild), while no re-bleeding cases were recorded.

CONCLUSION: EVL in combination with splenectomy with pericardial devascularization can block the collateral veins both inside and outside of the esophageal wall, and is more advantagious over splenectomy in combination with pericardial devascularization or EVL in preventing recurrence and re-bleeding of varices.

Resolution of Large Azygos Vein Aneurysm Following Stent-Graft Shunt Placement in a Patient with Ehlers-Danlos Syndrome Type IV

Ehlers-Danlos syndrome (EDS) type IV is a rare connective tissue disorder associated with thin-walled, friable arteries and veins predisposing patients to aneurysm formation, dissection, fistula formation, and vessel rupture. Azygos vein aneurysm is an extremely rare condition which has not been reported in association with EDS in the literature. We present a patient with EDS type IV and interrupted inferior vena cava (IVC) with azygos continuation who developed an azygos vein aneurysm. In order to decrease flow through the azygos vein and reduce the risk of aneurysm rupture, a stent-graft shunt was created from the right hepatic vein to the azygos vein via a transhepatic, retroperitoneal route. At 6 month follow-up the shunt was open and the azygos vein aneurysm had resolved.

Azygos lobe associated with esophageal atresia: a trap for the unwary

Presence of an associated azygos lobe may cause problems during thoracotomy on the right side for esophageal atresia. Awareness of the anomaly allows its recognition and appropriate management.

Comparison of breath-hold 2D phase-contrast with non breath-hold cine phase-contrast MRA in the assessment of azygos venous blood flow in portal hypertension

Azygos venous blood flow as an index of blood flow through the gastroesophageal collaterals and varices is of value in the prediction of gastrointestinal bleeding. Measurement of azygos venous blood flow has been achieved by non breath-hold (NBH) cine phase-contrast magnetic resonance imaging. The objective of this study was to compare the faster breath-hold (BH) phase-contrast technique with the standard (NBH) cine phase-contrast technique in the measurement of azygos blood flow. Thirty-two cirrhotic patients with esophageal varices were examined by magnetic resonance imaging using a BH technique and a NBH cine phase-contrast technique to measure the flow velocity, flow volume and calibre of the azygos vein at the mid-right atrial level. The flow values were obtained on the velocity image of the phase-contrast study. Values obtained from the two methods were evaluated statistically for the strength and significance of correlation by the Pearson test. Measurement by the BH method performed at full-inspiration as well as end-expiration was also obtained in 15 healthy volunteers. The breath-hold phase-contrast method has significant but weak correlation with non BH cine phase-contrast method in the measurement of azygos venous blood flow volume (r = 0.55, p < 0.01) and flow velocity (r = 0.43, p = 0.01). However, the calibre of the azygos vein gave a strong correlation in these two methods (0.82). In the subgroup of patients whose azygos blood flow velocity was greater than 7.4 cm/s, the correlation of azygos blood flow volume is strong (r = 0.80, p < 0.01). The azygos vein calibre remains highly correlated between the BH and NBH method, in both high flow velocity (r = 0.73) and low flow velocity (r = 0.83) groups. Breath-hold sequence leads to higher values for flow velocity and flow volume in the cirrhotic patients and also the control group. In patients with portal hypertension, BH 2D phase-contrast (PC) magnetic resonance angiography (MRA) could give a comparable estimation of the calibre of the azygos vein as the NBH 2D cine PC MRA but not for azygos flow volume. In patients with high azygos flow velocity, the strong correlation in flow volume between the BH and NBH method suggests that the BH method may be a time-saving alternative to the NBH method.

Improvement of protein-losing enteropathy by coil embolization of the left azygos vein

We report a 17-year-old boy with double-outlet right ventricle, atrioventricular septal defect, pulmonary stenosis, and persistent left superior vena cava who developed a protein-losing enteropathy, which was cured by coil embolization of the left azygos vein, thereby interrupting the vein-to-vein shunt.

Incidence of central vein stenosis and occlusion following upper extremity PICC and port placement

The purpose of this study was to determine the incidence of central vein stenosis and occlusion following upper extremity placement of peripherally inserted central venous catheters (PICCs) and venous ports. One hundred fifty-four patients who underwent venography of the ipsilateral central veins prior to initial and subsequent venous access device insertion were retrospectively identified. All follow-up venograms were interpreted at the time of catheter placement by one interventional radiologist over a 5-year period and compared to the findings on initial venography. For patients with central vein abnormalities, hospital and home infusion service records and radiology reports were reviewed to determine catheter dwell time and potential alternative etiologies of central vein stenosis or occlusion. The effect of catheter caliber and dwell time on development of central vein abnormalities was evaluated. Venography performed prior to initial catheter placement showed that 150 patients had normal central veins. Three patients had central vein stenosis, and one had central vein occlusion. Subsequent venograms (n = 154) at the time of additional venous access device placement demonstrated 8 patients with occlusions and 10 with stenoses. Three of the 18 patients with abnormal follow-up venograms were found to have potential alternative causes of central vein abnormalities. Excluding these 3 patients and the 4 patients with abnormal initial venograms, a 7% incidence of central vein stenosis or occlusion was found in patients with prior indwelling catheters and normal initial venograms. Catheter caliber showed no effect on the subsequent development of central vein abnormalities. Patients who developed new or worsened central vein stenosis or occlusion had significantly (p = 0.03) longer catheter dwell times than patients without central vein abnormalities. New central vein stenosis or occlusion occurred in 7% of patients following upper arm placement of venous access devices. Patients with longer catheter dwell time were more likely to develop central vein abnormalities. In order to preserve vascular access for dialysis fistulae and grafts and adhere to Dialysis Outcomes Quality Initiative guidelines, alternative venous access sites should be considered for patients with chronic renal insufficiency and end-stage renal disease.

[A case of unification anomalies of the superior vena cava and absence of the left brachiocephalic vein with dilated azygos and hemiazygos veins]

We report a case of dilated azygos vein simulating a tumor in the posterior mediastinum. The patient was a 47-year-old male who was found to have anomalies of unification of the superior vena cava and absence of the left brachiocephalic vein. He was admitted to our hospital because chest radiographs and computed tomography (CT) scans showed a well-circumscribed oval mass 2.5 cm in diameter, behind the bifurcation of the trachea. This lesion, which was markedly enhanced in chest CT, magnetic resonance imaging (MRI) and MR angiography (MRA) was diagnosed as a dilated azygos vein. An enlarged hemiazygos vein and collaterals were also recognized. Upon digital subtraction venography of both upper extremities, the right atrium and the left brachiocephalic vein could not been distinguished from the superior vena cava and the infraclavicular vein, respectively. Collaterals entering the azygos and hemiazygos veins were, however, recognized. It was considered that MRA and disital subtraction venography were very useful for confirmation of the diagnosis in this case.

Correlation between endoscopic and angiographic findings in patients with esophageal and isolated gastric varices

BACKGROUND/AIM

The correlation between angiographic vascular patterns and endoscopic findings in portal hypertension is not sufficiently known, and knowledge of the vascular anatomy may contribute to an improvement in endoscopic embolization and transjugular retrograde obliteration procedures. We propose a new vascular map that should prove useful for this purpose.

METHODS

Between April 1985 and December 1997 we performed percutaneous transhepatic portography in a selected group of 75 patients (16 women and 59 men), aged 43-71 years, from whom informed consent was obtained. All patients had been diagnosed endoscopically as having either esophageal or isolated gastric varices. According to the Child-Pugh classification, class A, B, and C cirrhosis was seen in 19, 40, and 16 patients, respectively. We created a vascular map of esophageal and isolated gastric varices, based on the opacification of the portal venous collaterals on percutaneous transhepatic portography. We compared the patients in both variceal groups in terms of portal venous pressure, main blood supply, and drainage routes.

RESULTS

We found that the portal collateral system was divided into two systems: the portoazygos venous system and the portophrenic venous system. The former contributed to the formation of esophageal and cardiac varices and the latter to the formation of isolated gastric varices located at the fundus or at both the cardia and fundus. The left gastric vein participated as blood supply in 70% of the isolated gastric varices and in 100% of the esophageal varices (p < 0.01). The posterior gastric vein participated as blood supply in 70% of the isolated gastric varices and in 24% of the esophageal varices (p < 0.01). We classified the main blood drainage routes of isolated gastric varices functionally into three types: gastrorenal shunt (85%), gastrophrenic shunt (10%), and gastropericardiac shunt (5%). The portal venous pressure in patients with esophageal varices was 358 +/- 66 mm H(2)O, whereas in patients with isolated gastric varices it was 262 +/- 44 mm H(2)O (p < 0.01).

CONCLUSION

We suggest that this new vascular map will be useful in endoscopic embolization and transjugular retrograde obliteration procedures for esophageal and isolated gastric varices.

Thoracoabdominal intestinal duplication with absent inferior vena cava

We report a rare case of thoracoabdominal intestinal duplication with absent inferior vena cava (IVC). The patient was initially explored with a mistaken diagnosis of diaphragmatic hernia on the basis of a chest radiograph and barium meal. However, a subsequent computed tomography scan revealed a mediastinal mass with an air-fluid level, a hugely dilated azygos vein, and an absent IVC. Thoracoabdominal exploration was required to excise the duplication cyst arising from the jejunum. We believe that this is the first report of this association.

Giant aneurysm of the azygos anterior cerebral artery--case report

A 77-year-old female presented with a giant aneurysm of the azygos anterior cerebral artery (ACA) manifesting as acute onset of akinetic mutism caused by enlargement of the aneurysm resulting from rapid thrombus formation within the aneurysmal sac. Thrombus removal to obtain decompression of the aneurysmal bulk and tension was performed before parent artery occlusion to prevent thromboembolic events. The aneurysmal neck was completely clipped with preservation of the parent artery and all branches. This strategy for direct neck clipping of a giant thrombosed distal ACA aneurysm can reduce the possibility of ischemic sequelae.

Azygos vein diverticulum

A 47-year-old woman, diagnosed with a diverticulum of the arch of the azygos vein, underwent surgical treatment. With nonspecific symptomatology, she presented one of the most uncommon anomalies of the large veins.

Isolated azygos continuation of the inferior vena cava in the elderly

A 70-year-old woman with the isolated anomaly of azygos continuation of the inferior vena cava is presented. The interest in this anomaly lies in its presentation as a mediastinal mass on the chest roentgenogram. This article reviews the embryogenesis and the diagnostic testing of this venous anomaly.

Anomalous inferior vena cava demonstrated by contrast-enhanced magnetic resonance venography

We discuss the technique of contrast-enhanced magnetic resonance venography and its advantages over other methods of imaging the veins of the chest. An example is presented of the results of this technique in a patient with agenesis of the hepatic segment of the inferior vena cava and azygos continuation.

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

Azygos vein enlargement can be detected in congestive heart failure, portal hypertension, inferior vena cava thrombosis, right atrial mural thrombosis, a pulmonary embolism, congenital azygos continuation to the inferior vena cava, and the arteriovenous fistula. Radiography, particularly computed tomography (CT), is very useful, not only in recognition of azygos vein enlargement, but also in evaluation of its etiology for the institution of the appropriate treatment of the diseases.

Azygos venous blood flow while fasting, postprandially, and after endoscopic variceal ligation, measured by magnetic resonance imaging

Using cine phase-contrast magnetic resonance (MR) imaging, we measured fasting and postprandial azygos blood flow in 15 cirrhotic patients with portal hypertension and 11 healthy controls. In 10 of the cirrhotics, measurements were made before and after prophylactic endoscopic variceal ligation therapy (EVL). Flow volume was measured in the azygos vein at the level of the midthoracic vertebra. Azygos blood flow was measured under basal fasting conditions and 30-40 min after ingestion of a 500 Kcal meal. Fasting azygos blood flow was 139 +/- 43 ml/min in controls vs 519 +/- 249 ml/min in cirrhotics (P < 0.01). Eating significantly increased azygos blood flow, by 38% in controls (P < 0.02) and by 27% in cirrhotics (P < 0.02), compared with fasting conditions. EVL markedly decreased azygos blood flow, by 25% compared with pre-EVL (P < 0.03). The cine phase-contrast MR velocity mapping method measured flow volume in the azygos veins. Azygos blood flow was markedly greater in the cirrhotics than in the controls. In the cirrhotics and controls, blood flow volume increased after eating. Azygos blood flow was significantly reduced by successful EVL.

Idiopathic saccular aneurysm of the azygos vein

Idiopathic saccular aneurysm of the azygos vein is a rare condition. We report the case of a 52-year-old man with saccular aneurysm of the azygos vein who underwent surgical resection. Preoperative dynamic computed tomography revealed strong and rapid enhancement of the chest mass. Magnetic resonance imaging showed a thoracic tumor with low signal intensity on the T1-weighted image and coexistence of low and high signal intensity on the T2-weighted image. Intraoperative findings showed cystic dilatation of the azygos vein. Although an accurate preoperative diagnosis of saccular azygos vein aneurysm is difficult, especially differential diagnosis between this anomaly and mediastinal tumors, a markedly enhanced mass shown by dynamic computed tomography was useful for the preoperative diagnosis of this anomaly.

Azygos continuation syndrome with aneurysm of the azygos vein: CT and MR appearances

We present a case of azygos vein continuation with aneurysm of the azygos vein simulating a tumor in the right upper mediastinum. The dynamic CT examination initially showed a structure of malignant appearance during the early arterial phase. Further dynamic CT revealed marked enhancement of the mass during the late venous phase, suggesting a vascular structure. Confirmation of diagnosis was made by MRI using a fast gradient echo imaging technique in cine mode, showing turbulent flow in the azygos aneurysm, and contrast-enhanced MR angiography, demonstrating a dilated azygos vein. Dynamic CT has a potential pitfall in the diagnosis of vascular structures.

[Dilatation of the azygos vein: an unusual cause of pulmonary mass]

Infrahepatic interruption of the inferior cava vein, is a rare congenital anomaly, usually associated with congenital heart and abdominal diseases. The systemic venous flow is accommodated by the dilated azygos. This dilated azygos arch accounts for the right paratracheal or mediastinal mass, and may be misinterpreted as a neoplasm. We report a case with this congenital vascular anomaly, associated with another of tracheobronchial tree.

[Pelvic and leg vein thrombosis in azygous and hemi-azygous vein continuity syndrome and complete agenesis of the inferior vena cava]

A patient with a complete agenesis of the inferior vena cava is presented. In this rare anomaly the blood of the pelvic veins is drained through the dilated venae lumbales, vena azygos and vena hemiazygos into the superior vena cava. The malformation was detected within the scope diagnostics of deep vein thrombosis. The diagnosis was made by sonography, computed tomography and magnetic resonance angiography.

Idiopathic saccular azygos vein aneurysm

We present a case of asymptomatic saccular aneurysm of the azygos vein. This abnormality is exceedingly rare. Dynamic computed tomography revealed strong enhancement of the mass, suggesting a vascular structure, which was very important for preoperative diagnosis. It is unclear whether the mass should be resected if the preoperative diagnosis has been made and the mass is not so large.