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Introduction Given the high variability and fragility of the thoracic duct, good knowledge of its anatomy is essential for its repair or to prevent iatrogenic postoperative chylothorax. The objective of this study was to define a site where the thoracic duct is consistently found for its ligation. The second objective was to define an anatomically safe surgical pathway to prevent iatrogenic chylothorax in surgery for aortic arch anomalies with vascular ring, through better knowledge of the anatomical relationships of the thoracic duct. Methods Seventy adult formalin-fixed cadavers were dissected. The anatomical relationships of the thoracic duct were reported at the postero-inferior mediastinum, at levels T3 and T4. Results The thoracic duct was consistently situated between the left anterolateral border of the azygos vein and the right border of the aorta between levels T9 and T10, whether it was simple, double, or plexiform. It was located medially, anteromedially, or posteriorly to the left subclavian artery in 51%, 21%, and 28% of the cases, respectively, at the level of T3. At T4, it was posteromedial in 27% of the cases or had no direct relationship with the aortic arch. Conclusion These results favor mass ligation of the thoracic duct at levels T9-T10 between the right border of the aorta and the azygos vein, eventually including the latter. To prevent iatrogenic postoperative chylothorax in aortic arch anomalies with vascular ring surgery, we recommend remaining strictly lateral to the left subclavian artery at the level of T3 to reach the aortic arch anomalies with vascular ring at T4.

Anterior surgical approaches to the thoracic spine are common procedures for the treatment of many diseases of the thoracic spine. Purpose of this anatomic study is to investigate the course of the segmental vessels of the thoracic spine for the anterior and lateral transthoracic approach from the right side. 26 formalin-fixed human cadavers (20 femaless/6 male) with an average age of 84.9 ± 8.3 (range 67–97) were included. The segmental arteries and veins of the right thoracic cavity coursing between the third and twelfth thoracic vertebral body have been investigated. To define the localization of the vessels in accordance with the associated vertebral bodies, the distance between the endplates and vessels was measured in the ventral, middle and dorsal parts. The results of the study reveal that not only one, but also two segmental arteries and veins may course over the right hemi-vertebral body, especially in the upper and middle thoracic spine. Furthermore, in the middle and lower thoracic spine (T7–T12) the vessels course over the middle and lower third of the craniocaudal extent of the vertebral body. On the contrary, in the upper thoracic spine (T3–T6), the vessels may course over the entire extent of the vertebral body. Due to these common anatomic variations and variability of the course of the segmental vessels, spinal surgeons should remain careful in the identification of the segmental vessels in order to minimize risk of vascular injury in case of right-sided anterior and lateral approach to the thoracic spine.

Persistent left superior vena cava (PLSVC) is one of the cardiac system abnormalities with a 0.3-0.5% incidence and caused by inadequate obliteration of the left anterior cardinal vein during embryonic development. Prognosis of PLSVC is generally assumed to be good if it is not accompanied by other cardiac system abnormalities. During the routine ultrasound control of a patient at 25th week of pregnancy at the Obstetrics and Gynecology Department of Mersin University, PLSVC anomaly was detected in an intrauterine fetus. Then, intrauterine death occurred and after removal of the deceased fetus, PLSVC diagnosis was confirmed by autopsy. According to the autopsy findings, right superior vena cava (SVC) and azygos vein were found in normal course. PLSVC opened into the right atrium via enlarged coronary sinus. There was no connection between the two SVCs. On the left side of posterior mediastinum, instead of hemiazygos or accessory hemiazygos veins, a vein symmetrical to azygos was opened into PLSVC, similar to the one on the right. No other cardiac anomaly associated with PLSVC or any other pathology in the other parts of body that could be responsible for death was discovered during autopsy. There was no evidence indicating that PLSVC played any role in intrauterine exitus of the present case. However, as mentioned in the literature, the ectopic beats in the atrium wall of patients with isolated PLSVC and enlarged coronary sinus may lead to pathologies in the conduction system of the heart. Considering the intrauterine death of an isolated PLSVC case associated with cardiac conduction pathologies, we recommend that the common assumption of 'isolated PLSVC is not associated with death' should be reviewed by studies on large series and even intrauterine cases should be closely monitored for cardiac arrhythmia.

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.

A spontaneous pneumothorax appears to be rarely seen in patients with an azygos lobe, although this normal variant is incidentally found on CT and chest X-ray. The displacement of the azygos vein from the azygos lobe to the paramediastinal position indicates previous pneumothorax. We report two patients (a 59 and a 27-year-old female) where the finding of an azygos lobe without an azygos vein proved to be a sign of previous iatrogenic pneumothorax. Documentation of an azygos lobe without azygos vein is highly suggestive of a previous pneumothorax. This observation may indicate an iatrogenic cause, because of the possible protective effect of an azygos lobe to the occurrence of spontaneous pneumothorax.

The surgical treatment of thoracic kyphosis frequently requires an anterior release, which can be carried out by an open or endoscopic technique. This study concerns the reference points which are essential from the anatomic view for minimizing the operative risks. Furthermore we wanted to find the most convenient video-assisted thoracoscopic surgery (VATS) technique for transection of the anterior longitudinal ligament (ALL). Transection of the ALL, as well as discectomy, was performed using this technique. The extensive anatomic dissection of 12 fresh cadavers was performed to define possible technical errors and surgical complications. The development of new instruments has made the VATS approach to the ALL a viable alternative to open procedures. With the help of a standardized technique, the isolated thoracoscopic ligamentous transection required less time than the comparable open procedure. The anatomic study showed, that in no case was a ligation of the intercostal or segmental vessels necessary as part of the approach to the spine, once an adequate mobilization of the esophagus and azygos vein had been carried out. The risk of an ischemic lesion of the spinal cord was thereby reduced. The thoracoscopic, limited anterior release consisting of a multilevel transection of the ALL proved to be a rapid and reliable procedure. Our anatomic studies provides suitable the reference points.

The authors report an exceptional and well-documented case of interruption of the retrohepatic segment of the inferior vena cava with an "azygos continuation", combined with absence of the portal vein. The only known combination of congenital anomalies of the inferior vena cava and the portal vein was that of an "azygos continuation" and a preduodenal portal vein. The double interruption, portal and inferior caval, may be associated with a disturbance of preferential flows induced by the left umbilical thrust. According to hemodynamic theory, the left umbilical flow is the determining factor in organogenesis of the portal vein and the retrohepatic segment of the inferior vena cava.

Multiple variations of the azygos venous system were detected during routine dissection. The hemiazygos vein was underdeveloped. On the left side of the thorax, posterior intercostal veins between the 8th and 11th intercostal spaces and the subcostal vein drained into the azygos vein independently. In addition, the posterior 4th, 5th, 6th and 7th intercostal veins united and formed two superior and inferior trunks. The superior common trunk, at the level of the T4 vertebra, crossed the vertebral column obliquely, lying anterior to the aorta and posterior to the esophagus, opening into the azygos vein at the level of the T4 vertebra. The other structures in this part were normal. There were different courses of the azygos vein system. This variation is important in mediastinal surgery and also in the interpretation of radiographs.

A case of double superior vena cava lacking the left brachiocephalic vein was found. The left superior vena cava directly continued to the accessory hemiazygos vein without anastomosis with the coronary sinus. Therefore, the blood from the left superior vena cava drained into the right superior vena cava via the transverse anastomosis between the left and right azygos lines. It was thought that embryologically 1) the inter-precardinal vein was not formed, and 2) the left precardinal vein did not continue to the common cardinal vein, rather it drained into the left azygos line. This case may represent one of the most basic arrangements of the superior caval system.

The relationships of a tumor of the thoracic esophagus to the adjacent mediastinal structures are currently studied by means of computed tomography (CT), magnetic resonance imaging (MRI) and, more recently, by echoendoscopy. However, the assessment of axial mediastinal CT and of MRI in the coronal and sagittal planes calls for some degree of experience. To further this training a sectional anatomy is proposed in correlation with imaging of the thoracic esophagus and the posterior mediastinum. Ten fresh subjects whose vascular networks had been previously injected with colored resin were sectioned along the three planes of space after positioning under CT monitoring. The axial sections were compared with the CT images made with a GE 9800 Quick scanner. Three frontal and sagittal sections were compared with the MRI images made with a GE Signa apparatus using a high magnetic field. The relations of the esophagus were studied at three levels: the supra-azygo-aortic segment, where it is related to the left subclavian artery; the inter-azygo-aortic segment, where access to the esophagus is barred on the left by the aortic arch and on the right by the arch of the azygos vein, section of which provides ample access; and the sub-azygo-aortic segment, where the esophagus passes behind the left main bronchus and to the right of the descending aorta, two organs whose invasion contraindicates excision of a tumor of the esophagus but is difficult to assess by current thoracic imaging techniques. The esophagus then descends behind the left atrium; the investigation of the kinetics of the heart cavities by transesophageal echocardiography is an application of this anatomic relationship. These anatomic sections should form useful teaching aids for the study of CT and MR images by radiologists and should help surgeons to assess the possibilities of tumor excision.

The authors report a case of left IVC with a preferential hemiazygos-azygos drainage associated with an accessory left superior intercostal vein drainage. This exceptional congenital malformation which finds its place in polysplenia was studied by cavography, CT and MR imaging.