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Za unerwienie i zaopatrywanie w składniki odżywcze ścian klatki piersiowej odpowiada powrózek naczyniowo-nerwowy. W swoim przebiegu charakteryzuje się on układem, w którym to żyła międzyżebrowa jest strukturą najbardziej chronioną. Poniżej żyły znajduje się znacznie bardziej narażona na uszkodzenia tętnica międzyżebrowa, natomiast nerw międzyżebrowy jest strukturą, która jako pierwsza ulega uszkodzeniom w przypadku ran kłutych klatki piersiowej. Pomimo tak nietypowego układu struktur w pęczku, możliwe jest wykorzystanie tej wiedzy w praktyce klinicznej do przeprowadzenia zabiegów takich jak torakocenteza, torakotomia, czy też blokada nerwu międzyżebrowego.

Introduction. Intravascular procedures, including central venous catheterization and placement of cardiac implantable electronic device (CIED) leads, present an opportunity for radiological assessment of the relevant vessels. Obtaining vascular access via left clavipectoral triangle veins may lead to an unintentional catheter/lead insertion into a left brachiocephalic vein (BCV) tributary. This article presents the left-BCV tributaries encountered during CIED implantation procedures and discusses the potential impact of vessel topography on the course of such procedures. Material and methods. Venography records of de novo CIED implantation procedures conducted between 2014 and 2018 were analyzed retrospectively. The indication for these venographies had been the need to determine the cause of difficulties in threading a lead through the venous system. As the title suggests, this paper focuses only on the records illustrating the presence and course of left-BCV tributaries. Results. Out of a total of 315 venographies, we found 12 cases of left-BCV tributaries, including nine left superior intercostal veins (SICVs), two left internal thoracic (mammary) veins (IMVs), and one inferior thyroid vein. Other veins had not been visualized. Conclusions. The left SICV and, less commonly, left IMV were the most commonly visualized left-BCV tributaries in the analyzed imaging records of de novo CIED placement procedures. The anatomical variants of those vessels that drain into the left BCV from below, at the outer or convex wall of the bend in the left BCV, increase the risk of unintentional CIED lead or central venous catheter insertion.

Objective To describe a technique for anastomosis of the thoracic duct (TD) to the 11th or 12th intercostal vein (ICV) using a microvascular anastomotic coupler (MAC) in the dog. Study design Cadaveric study. Animals Eight beagles. Methods A right paracostal laparotomy and 10th intercostal thoracotomy were performed in each dog. Mesenteric contrast lymphography was used to identify the TD and its branches on fluoroscopy. The TD and adjacent 11th or 12th ICV were isolated, double ligated, and divided using a surgical microscope. The caudal TD and proximal ICV were anastomosed in an end-to-end fashion using a 1.5 mm or 2 mm MAC. Mesenteric lymphography was repeated to document patency of the anastomosis. Results The TD was identified via lymphography in all dogs; five dogs had a single duct, and three dogs had additional branches. The anastomosis was successful in all eight dogs, and flow into the azygos vein without leakage was confirmed via lymphography. Conclusion End-to-end anastomosis of the TD to an ICV using a MAC was technically feasible in the canine cadaver. Clinical significance Lymphaticovenous anastomosis combined with TD ligation may have application as a treatment for idiopathic chylothorax. By maintaining the flow of chyle from the abdominal lymphatics to the systemic circulation, this procedure may reduce the stimulus for collateral circulation and persistent flow to the cranial mediastinal lymphatics.

Some patients with intestinal failure, who are dependent on total parenteral nutrition for long periods, suffer from a lack of suitable conventional venous access points, including axillary, external jugular, internal jugular, subclavian, saphenous, and the brachio-cephalic and femoral veins, due to their occlusion. Furthermore, extensive central venous stenosis and/or thrombosis of the superior and inferior vena cava may preclude further catheterization, so uncommon routes must be used, which can be challenging. In such patients, the azygos vein via the intercostal vein is a viable candidate. Thoracotomy-assisted, thoracoscopy-assisted, and cut-down procedures are currently suggested such access. We found that ultrasound-guided percutaneous puncture method was a safe and minimally invasive approach and successfully placed two central venous lines in preparation for small bowel transplantation via two different intercostal veins (ninth and tenth). Although the lung was actually located just below the target veins, an ultrasound provided augmented and clear vision, which contributed to the safe performance of the procedure without the need for invasive surgical intervention, such as thoracotomy, thoracoscopy, or rib resection using the cut-down technique. Furthermore, constant positive-pressure ventilation during vein puncture under general anesthesia also helps avoid venous collapse. Despite carrying a slight risk of light injury to the lung, artery, and nerve along with the vein compared to other procedures, we believe that ultrasound-guided puncture under general anesthesia is feasible as a minimally invasive method.

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.

Background: Sympathetic chain interruption is the gold standard treatment for essential hyperhidrosis. Postoperative compensatory hyperhidrosis, the main reason for patients' dissatisfaction, is reduced by selectively lesioning white and grey rami communicantes (ramicotomy).Objective: To develop an endoscopic surgical technique that interrupts only T3 and T4 grey rami communicantes to minimize compensatory hyperhidrosis.Material and Methods: T3 and T4 grey rami communicantes ramicotomy in fifteen cold-preserved cadavers through a uniportal axillary endoscopic approach. The sympathetic chain, its ganglia, and white rami communicantes were left intact. On opening the chest, the sympathetic chain, rami communicantes and ganglia were dissected, photographed, measured and excised for histological examination.Results: Dissecting the grey rami communicantes is feasible as they consistently lie between the intercostal nerve and the homonymous sympathetic ganglion. At some levels, Kuntz nerves, as well as more than one grey ramus communicans, can be found. White rami communicantes are more medial, therefore damaging them can be avoided. Intercostal veins can be obstructive, but these can be controlled via coagulation or clipping if necessary.Conclusion: Uniportal endoscopic selective excision of the T3 and T4 grey rami communicantes is feasible without damaging the white rami communicantes, the sympathetic chain or its ganglia. Clipping the grey rami communicantes is technically possible but not reliable due to their thin diameter. This study confirms that T3 and T4 grey rami sympathetic block is technically feasible. Its application might reduce compensatory hyperhidrosis, but clinical studies are needed.

Introduction The azygos system of veins (ASV) is a very variable structure characterized as a communication between the inferior and superior vena cava, having the azygos vein (AV), the hemiazygos vein (HV), and the accessory hemiazygos vein (HAV) as its main components, which are responsible for the mediastinal viscera and for the thoracoabdominal wall drainage. The aim of the present study is to report an anatomical variation found in a male cadaver at the Laboratory of Anatomy of the University Center of UNIFACISA, Campina Grande, PB, Brazil. Case Report In the posterior mediastinum, the union of the HV, of the HAV, and of the 8th left posterior intercostal vein formed a common trunk at the level of the left 8th intercostal space, crossing the mediastinum posterior to the aorta artery, ending up in the AV, in the right hemithorax. Conclusion The study of the anatomical variations of the ASV is important and will provide knowledge for physicians not to confuse them with pathological processes in imaging exams. Moreover, it can provide safety in surgical approaches of the thorax.

During an educational dissection of a 72-year-old Chinese male cadaver, the hemiazygos vein (HAV) coursing the left side that drains into the persistent left superior vena cava was observed. The HAV was formed at the junction of the 9th to 11th right posterior intercostal veins, right subcostal vein, 5th to 11th left posterior intercostal veins, and left subcostal vein; it then ascended posteriorly to the thoracic aorta. After collecting the accessory hemiazygos vein, it crossed over the aorta and the pedicle of the left lung via the hemiazygos arch, then converged with a communicative branch (vein of Marshall) that emerged from the left brachiocephalic vein to form the persistent left superior vena cava and entered the pericardium at the level of the sixth thoracic vertebra. Upon opening the pericardium of our cadaver, the persistent left superior vena cava was found to drain directly into the significantly dilated coronary sinus at the level of the eighth thoracic vertebra. The azygos vein was formed by the union of the first to eighth right posterior intercostal veins and appeared to be finer and shorter than the HAV. The persistent left superior vena cava might be the result of incomplete degeneration of the left posterior cardinal vein. Knowledge of such variations could be of great value to surgeons placing peripherally inserted central catheters because incorrect placement of the azygos venous system can be detrimental to the patient. In addition, during heart surgery, awareness of such variations may prevent major complications, such as hemorrhage or damage to vascular structures, and possibly also provide new insights and perspectives to cardiovascular surgeries.

Knowledge of variations of azygos and hemiazygos veins is of importance to cardiothoracic surgeons and radiologists during various surgical, radiological, and echography techniques. We report some unique variations of azygos system of veins observed during dissection classes for undergraduate medical students. The azygos vein was formed as usual by the union of right subcostal and ascending lumbar veins. The vein ascended upward and to the left to reach the midline at the level of the 9th thoracic vertebra. After ascending till 5th thoracic vertebra, it gradually inclined to the right of midline and terminated by opening into the superior vena cava at the level of the 3rd thoracic vertebra. There was no major variation in the tributaries of the azygos vein on the right side, except that the right superior intercostal vein crossed behind the azygos vein from right to left and opened into the left side of the azygos vein. Further, two anastomotic veins connected the 10th, 11th and 12th posterior intercostal veins with each other to form two anastomotic circles on the right side of 10th to 12th thoracic vertebrae. The hemiazygos vein bifurcated on the left side of the 10th thoracic vertebra and the two ends opened into the azygos vein at the level of 9th and 10th thoracic vertebrae forming a venous circle in front of the 10th thoracic vertebra. The course of accessory hemiazygos vein was noteworthy. Instead of its classic descending course, the vein ascended upward from the left side of the 8th thoracic vertebra till the 6th thoracic vertebra before opening into the azygos vein.

AIM The surgical assumption of responsibility of the pancreatic pain requires either a truncular coelioscopic or radicular neurectomy of greater splanchnic nerves (gsn). The goal of our work is to describe the way and relations of the right gsn which are variable and rarely described. This constitutes an undeniable peroperational hemorrhagic risk during splanchnicectomy. MATERIAL AND METHODS After a double side thoracotomy and a bilateral sterno-clavicular desarticulation on 15 adult cadaveric subjects preserved by method of Winckler we removed the sterno-costal drill plate as well as the ventral rib arch and proceeded to a mediastinal evisceration of the thorax. Then we respected only the thoracic aorta and the oesophagus, the azygos venous system, the thoracic duct and the thoracic sympathetic chain. In some of the subjects, the azygos vein was injected (after catheterization of its stick) using gelatine coloured with blue paint. We studied the way and vascular relations of the right gsn. We measured the transverse distances between the origin of the gsn on one hand and the longitudinal axes of the azygos vein and the thoracic duct on the other hand. RESULTS The relations of the right gsn trunk during its way related to the azygos vein in particular its constitutive origin and its affluents: ascending lumbar vein and twelfth intercostal vein. Sometimes the thoracic duct even a lymphatic node was near the gsn in the posterior infra-mediastinal space. A classification of the way and vascular relations of the right gsn in the thorax identified 3 anatomical types. The average distances separating the right gsn on one hand from the azygos vein and the thoracic duct on the other hand were respectively 5.7 mm and 11.2 mm. CONCLUSION The vascular relations of the right gsn are very variable from one subject to another but primarily venous, sometimes lymphatic. They concerned the great thoracic vessels whose respect is essential in particular at the time of mini-invasive access procedure for a cœlioscopic splanchnicectomy.

Azygos venous system drains the venous blood from thoracic wall. Knowledge of variations of its course and tributaries is important to cardiothoracic surgeons, radiologists and orthopedic surgeons. We observed the following variations in the azygos veins. Both azygos and hemiazygos veins were formed by union of lumbar azygos and subcostal veins of corresponding sides. The ascending lumbar vein did not drain into the azygos system. The hemiazygos vein had a larger diameter than the lower part of azygos vein and it joined azygos vein at the level of seventh thoracic vertebra. Accessory hemiazygos vein was totally absent. The azygos vein received 4th to 11th right posterior intercostal veins and also received 3rd to 6th left posterior intercostal veins. Hemiazygos vein received 7th to 11th left posterior intercostal veins.

The internal vertebral venous plexus (IVVP) plays a putative role in thermoregulation of the spinal cord. Cold cutaneous venous blood may cool, while warm venous blood from muscles and brown fat areas may warm the spinal cord. The regulating mechanisms for both cooling and warming are still unknown. Warm venous blood mainly enters the IVVP via the intervertebral veins. In the thoracic area these veins are connected to the posterior intercostal veins. In this study, anatomical structures were investigated that might support the mechanisms by which warmed venous blood from the intercostal muscles and the recently described paravertebral patches of brown adipose tissue are able to drain into the vertebral venous plexus. Therefore, tissue samples from human cadavers (n = 21) containing the posterior intercostal vein and its connections to the IVVP and the azygos veins were removed and processed for histology. Serial sections revealed that the proximal parts of the posterior intercostal veins contained abundant smooth muscle fibers at their opening into the azygos vein. Furthermore, the walls of the proximal parts of the posterior intercostal veins contain plicae that allow the vessel to dilate, thereby allowing it to serve as a pressure chamber. It is suggested that a cold induced closure of the intercostal/azygos opening can result in retrograde blood flow from the proximal posterior intercostal vein towards the IVVP. This blood flow would be composed of warm blood from the paravertebral brown adipose tissue and blood containing metabolic heat from the muscles draining into the intercostal veins.

The thoracic wall consists of the osseo-cartilaginous throacic cage, the interconnecting muscles, the muscles on top, the fascia, the nerves and vasculature, the subcutaneous tissue, the skin, and the mammary glands that lie within the subcutaneous tissue. The thoracic cage is pinned by the sternum where the ribs emerging from the vertebrae converge. Flanked by the muscles of the upper limbs the muscles of the thoracic wall include the external and internal intercostal muscles and the diaphragm which separates the thoracic cavity from the abdominal cavity. 12 pairs of thoracic spinal nerves divide into anterior and posterior primary rami to supply the thoracic wall. The anterior rami form the intercostal nerves that further provide branches that innervate the muscles, skin and other structures of the thorax. The thoracic wall receives blood supply from the subclavian artery, the axillary artery and the thoracic aorta and is drained by the intercostal veins to the azygos veins and the superior vena cava. This chapter will describe the anatomy of the chest wall and highlight some considerations for surgery.

Atypical anatomy may be encountered unexpectedly and undiagnosed in clinical practice, and this is especially important during the performance of interventional procedures such as transvenous implantation of cardiac electronic devices. The body of the first rib can be absent. If this not noticed, pneumo-/haemothroax may be induced during subclavian vein puncture as the needle may enter the first intercostal space rather than the costo-clavicular angle. The cephalic vein may pursue a supraclavicular course, the axillary vein may drain into an intercostal vein rather than the axillary vein, and the entire length of the axillary-subclavian-brachio-cephalic vein may be absent. Device implanters should be vigilant about the possibility of these anatomical variations, and be equipped with the knowledge and spectrum of alternative techniques needed to deal with them.

Chylothorax is a rare clinical condition characterized by high triglyceride and low cholesterol levels in milky pleural aspirate. Generally, it occurs through leakage of chyle as result of trauma or malignancy. Chylothorax due to tuberculous lymphadenitis is very rare clinical condition that has only been documented in a few cases. Although precise pathogenesis is not known, enlarged mediastinal and hilar lymph nodes are thought to be associated with opening of collateral anastomosis between thoracic duct and the azygos and intercostal veins by creating pressure on thoracic duct and cisterna chyli. Presently described is case of chylothorax thought to be due to compression from mediastinal tuberculous lymphadenitis, and which had complete remission after antituberculosis treatment.

Background: This study compared porcine and human thoracic spine anatomies for a better understanding of how structures encountered during thoracoscopy differ between training with a porcine model and actual surgery in humans. Methods: Parameters were measured including vertebral body height, width, and depth; disc height; rib spacing; spinal canal depth and width; and pedicle height and width. Results: Although most porcine vertebral structures were smaller, porcine pedicle height was significantly greater than that of humans because the porcine pedicle houses a unique transverse foramen. The longus colli and psoas attach, respectively, to T5 and T13 in swine and to T3 and T12 in humans. In swine, the azygos vein generally was absent. The intercostal veins drained into the hemiazygos vein. Conclusions: Several thoracoscopically relevant anatomic differences between human and porcine spinal anatomies were identified. A thoracoscopic approach in a porcine model probably is best performed from the right side. The best general working area is between T6 and T10.

A novel technique for chelonian venipunture is described. Angiographic studies using radio-opaque iohexol, static radiography, and video fluoroscopy were undertaken in several chelonian species. Latex injected dissections were also performed to confirm the vascular anatomy. These studies indicate that a clinically useful venipuncture site is present in the anterior dorsal midline at the junction of the common intercostal veins and the caudal cervical branch of the external jugular veins, located just craniad of the last mobile cervical vertebra.

Toracoscopia é o método de visibilização da cavidade torácica através de endoscópio rígido ou flexível, indicado como exame auxiliar para diagnóstico das diversas afecções do tórax. Pode ser realizada com o animal sob anestesia geral ou em posição quadrupedal através de anestesia local associada ou não a sedativos. Neste trabalho, foram utilizados seis eqüinos hígidos, que foram submetidos a toracoscopia, em posição quadrupedal, nos dois hemitórax, com intervalo de 15 dias entre cada procedimento. Durante o exame, pôde-se observar as diversas estruturas da cavidade torácica, tais como: músculo diafragma (porção muscular e tendínea), hiato esofágico, mediastino, aorta, troncos dorsal e ventral do nervo vago, ducto torácico, veia ázigos, veias intercostais, músculos intercostais, costelas, tronco nervoso simpático, tronco vascular toracocervical, traquéia, pulmão (lobo cranial e caudal), esôfago, pericárdio, veia cava caudal, nervo frênico e linfonodos aórticos. Discretas alterações foram observadas ao exame físico, laboratorial e ultra-sonográfico no período pós-operatório, sem que trouxessem prejuízos ao desenvolvimento do experimento e recuperação do animal. A toracoscopia mostrou ser exame de auxílio importante, pela facilidade, rapidez de execução, ampla visibilização da cavidade pleural e trauma mínimo ao paciente. Thoracoscopy is the technique based upon the thoracic cavity visualization by means of rigid or flexible endoscope. It is indicated as an additional diagnostic aid to better define thoracic diseases. It can be performed either in an animal subjected to general anesthesia or in a horse standing on stocks with local anesthesia with or without sedative. Six healthy horses were used in this study they were subjected to thoracoscopy in both hemithorax, standing on stocks, with a 15-day interval between each procedure. It was possible to visualize several thoracic structures through the 13th intercostal space aproach, such as: diaphargma (muscular and tendineous portions), esophageus hiatus, mediastinum, aorta, vagus nerve dorsal and ventral trunk, thoracic ductus, azigus vein, intercostal veins and muscles, ribs, sympathetic nervous trunk, thoracocervical vascular trunk, trachea, lungs (cranial and caudal lobes), esophagus, pericardium, caudal cava vein, phrenicus nerve and aortic linphonodes. Slight alterations were observed in physical, laboratorial and ultra-sonographic exams during pos operative period those alterations did not compromise either this experiment development or the animals well being. By being an easy and fast procedure wich allows pleural cavity broad visualization and pacient minimal trauma, thoracoscopy makes itself a great diagnostic aid exam.

This article provides a practical approach to the clinical implications and importance of understanding the collateral venous anatomy of the thorax. Routine radiography, conventional venography, computed tomography (CT), and magnetic resonance (MR) imaging studies provide correlative anatomic models for the demonstration of how interconnecting collateral vascular networks within the thorax maintain venous stability at all times. Five major systems comprise the collateral venous network of the thorax (Fig. 1). These include the paravertebral, azygos-hemiazygos, internal mammary, lateral thoracic, and anterior jugular venous systems (AJVS). The five systems are presented in the following sequence: (a) a brief introduction to the importance of catheter position and malposition in understanding access to the thoracic venous system, (b) the anatomy of the azygos-hemiazygos systems and their relationship with the paravertebral plexus, (c) the importance of the AJVS, (d) 'loop' concepts interconnecting the internal mammary and azygos-hemiazygos systems by means of the lateral thoracic and intercostal veins, and (e) the interconnecting venous networks on the thoracic side of the thoracoabdominal junction. Certain aspects of the venous anatomy of the thorax will not be discussed in this chapter and include (a) the intra-abdominal anastomoses between the superior and inferior vena cavae (IVC) via the internal mammary, lateral thoracic, and azygos-hemiazygos systems (beyond the scope of this article), (b) potential collateral vessels involving vertebral, parascapular, thyroidal, thymic, and other smaller veins that might anastomose with the major systems, and (c) anatomic variants and pitfalls that may mimic pathologic conditions (space limitations).

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.

Bathyergus suillus are subterranean rodents found in the Western Cape of South Africa, where they inhabit sandy, humid burrows. Vertebral venous plexuses around the vertebral column have been implicated in aiding the maintenance of a constant central nervous system temperature via its connections with muscles and interscapular brown adipose tissue. The morphology of the vertebral venous plexuses and its connections in B.suillus were investigated. Frozen (n = 10) animals were defrosted; the venous system injected with latex and the vertebral venous plexuses, azygos- and intercostal veins dissected along the dorsal and ventral aspects of the vertebral column. Specimens (n = 4) were used for histological serial cross sections of the thoracic vertebrae. Veins drained from the interscapular brown adipose tissue to the external vertebral venous plexus, via a dorsal vein at the spinous process of T2 which might represent the "vein of Sulzer" described in rats. The intercostal veins cranial to the level of T8 drained directly into the ventral external vertebral venous plexus instead of into the azygos vein as seen in rats. The azygos vein was situated ventrally on the thoracic vertebral bodies in the median plane as opposed to most rodents that have a left sided azygos vein. The internal vertebral venous plexus consisted of two ventrolateraly placed longitudinal veins in the spinal epidural space. Veins from the forelimbs entered the internal vertebral venous plexus directly at the levels of C7 and T1 and have not been described in other rodents. Serial histological sections, revealed no regulatory valves in vessels leading toward the internal vertebral venous plexus, allowing blood to presumably move in both directions within the vertebral venous plexus. The vertebral venous plexus of B. suillus shows similarities to that of the rat but the vessels from the forelimbs draining directly into to the internal vertebral venous plexus and the position of the azygos vein and the intercostal veins draining into the external vertebral venous plexus are notable exceptions.

Some children requiring chemotherapy, total parenteral nutrition, or repeated blood sampling for long periods have no more axillary, internal jugular, external jugular, saphenous, or femoral veins available for cannulation. In such patients, the central venous system can still be accessed via alternate routes e.g. the azygos vein, the gonadal vein or the inferior epigastric vein.We report the use of: 1) The inferior epigastric vein for placement of the catheter into the IVC in 20 patients. 2) The right gonadal vein for placement of the catheter using a retroperitoneal approach in five pediatric patients. 3) The second and third right intercostal veins for placement of the catheter by right intrapleural thoracotomy in five pediatric patients. Pre-procedural assessment of the patency of these veins was done using colour Doppler ultrasonography and confirmation of occlusion of common sites used for central venous access.A total of 38 implantable venous access devices (IVAD) were inserted in 30 patients. The average age at operation was 1.4 years (range 1 month to 12 years). Infection was seen in two patients, venous thrombosis in two. The average longevity of IVAD is 6.5 months. Recovery from the procedure was uncomplicated and the patients were able to receive complete intravenous medication or nutritive mixtures after the insertion of the catheter.The knowledge of alternate routes to obtain central venous access for children requiring chemotherapy, total parenteral nutrition, or repeated blood sampling for long periods is critically important, and the azygos system, right gonadal vein or the inferior epigastric vein can be used when standard accessible veins are unavailable.

Central venous lines are of particular importance in seriously ill children that require parenteral nutrition, chemotherapy, or other medications. The jugular or subclavian veins are ordinarily used for primary access. Alternatives include the femoral veins, the intercostal veins, and transhepatic approaches. If the use of these standard sites of placement is made impossible, due, for example, to chronic thrombosis, an alternative approach has to be found. The following report presents the case of an 11-year-old girl with short-bowel syndrome and a desperate need for parenteral nutrition. Over the course of her treatment, she developed chronic thrombosis of the jugular, subclavian, and femoral veins, as well as thrombosis of the inferior vena cava. As an alternative route for central venous access, we describe a successful direct placement of a tunnelled catheter into the right atrium via a right anterolateral thoracotomy.

A 28-year-old woman suffered severe back pain and headache during exercising on three occasions during the prior two-month period. On admission, the physical examination revealed symptoms of meningeal irritation, nuchal rigidity, severe headache, continuous nausea, and vomiting. Cerebral computed tomography of the intracranial subarachnoidal space revealed no subarachnoid hemorrhage. Her cerebrospinal fluid was bloody. Spinal magnetic resonance imaging identified a posterior mediastinal tumor adherent to the left side of the 5th thoracic vertebra and an abnormally expanded blood vessel near the mediastinal tumor. In addition, a high signal intensity lesion appeared to be present on the surface of the spinal cord. A mediastinal neoplasm was removed through standard thoracotomy. During surgery, marked enlargement was noted in some veins (hemiazygos and 5th intercostal veins) which apparently had been constricted by the mediastinal tumor. Surgical and radiological findings suggested a relationship between the constricted venous return due to the tumor and the patient’s spinal subarachnoid hemorrhage.

Dear Editor, With great interest we read the article by Schroder et al. to be published in a forthcoming issue of the Journal of Gastrointestinal Surgery in which they investigated the potential value of resecting the azygos vein in transthoracic esophagectomy for esophageal cancer. During (robot-assisted) thoracoscopic esophagectomy, the trunk of the azygos vein is often preserved as the scopic ligation of the numerous intercostal veins is technically difficult and time-consuming. One may postulate that this may negatively affect the extent of lymph node harvesting or the circumferential radical (R0) resection rate. Schroder et al. have, therefore, performed a prospective evaluation on the amount of lymph nodes surrounding the azygos vein in 92 patients with esophageal cancer having undergone open transthoracic esophagectomy with two-field lymphadenectomy. Lymph nodes near the azygos vein were identified in 65% of patients and metastases in these lymph nodes were found in 8%. They, therefore, conclude that the dissection of the azygos vein should not be abandoned, irrespective of the surgical approach. A comment should be made on the design of the study. As clearly shown in Figure 2 of their article, they dissected the azygos vein with the surrounding tissues sharply from the esophagus, which is not representative for (robot-assisted) thoracoscopic esophagectomy. In (robot-assisted) thoracoscopic esophagectomy, subsequent to the ligation of the azygos arch, the mediastinal dissection of the esophagus and surrounding tissues is performed sharply along the azygos trunk. In this way, the fatty tissue in between the esophagus and the azygos vein (including the lymph nodes of stations 108 and 110) as well as the thoracic duct are included in the esophageal resected specimen and are not left in situ when the trunk of the azygos vein is preserved. The number of lymph nodes that will be left in situ with (robot-assisted) thoracoscopic esophagectomy will, therefore, be much less than stated in this article. Indeed, in our recently published cadaveric study in which we investigated an identical research question, a mean amount of only 0.67 lymph nodes were identified around the azygos vein using the thoracoscopic dissection method. Using this approach, in 60% of cadavers, no lymph nodes near the azygos vein were detected at all. With regard to the possible effect of azygos vein preservation on the radical resection rate, we can refer to our first report on 21 esophageal cancer patients having undergone robot-assisted thoracoscopic esophagectomy. The R0 resection rate of 76% in that series is similar to that of open transthoracic esophagectomy. In our opinion, it is, therefore, justified to preserve the azygos trunk during (minimally invasive) transthoracic esophagectomy.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:04:07Z No. of bitstreams: 0 Made available in DSpace on 2013-08-22T19:04:07Z (GMT). No. of bitstreams: 0 Previous issue date: 1999-01-01 Made available in DSpace on 2013-09-30T20:06:44Z (GMT). No. of bitstreams: 0 Previous issue date: 1999-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:17:03Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T15:17:03Z (GMT). No. of bitstreams: 0 Previous issue date: 1999-01-01 O comportamento da veia ázigos, sua formação e topografia foram estudados em 10 cutias (Dasyprocta aguti, rodentia) adultas (6 machos e 4 fêmeas, capturadas no estado do Piauí, Brasil). Este trabalho tem por objetivo constituir a base de outras investigações, particularmente aquelas referentes à exploração zootécnica desta espécie. O sistema de veia ázigos foi injetado com látex - Neoprene 671, e os animais foram colocados em solução aquosa de formol a 10%, e dissecados. em todas as espécies foi observado que a veia ázigos sempre chega na veia cava cranial em nível do quarto espaço intercostal. A veia ázigos recebe em (50%) dos casos as veias intercostais à direita e (50%) à esquerda. As tributárias da veia ázigos são: as veias frênicas (100%) e a veia bronco esofágica (30%). A veia hemiázigos aparece em todos os casos à esquerda e em 60% dos casos à direita. A veia ázigos comunica-se com a veia hemiázigos esquerda (90%), e com a direita (100%), com a veia cava caudal e veias intervertebrais, com igual freqüência (30%). The behaviour of the azygos vein, its formation and topography were studied in 10 cutias (Dasyprocta aguti, rodentia) adults (6 males and 4 females) captured in the State of Piauí, Brazil. This research intends to be a base for other investigations, particularly those with reference to zootechnical exploration of this species. The azygos venous system was injected with latex (Neoprene 671), then the animals were put in watery solution of formol 10%, and dissected. In all specimens it was observed that the azygos vein always arrives in the cranial vena cava on a level with fourth intercostal space. The azygos vein receives more frequently (50%), the intercostal veins on the right side and 5 (50%) on the left one. The tributaries of the azygos vein are the phrenic veins (l00%), and the broncoesophagea vein (30%). The hemiazygos vein is in all cases on the left side and in 60% of the cases on the right side. The azygos vein communicates with the left hemiazygos vein (90%), with the right one (100%), and with the vena cava caudal and intervertebral veins, with equal frequency (30%). Universidade Federal do Pauí Universidade Estadual Paulista Faculdade de Odontologia Universidade de São Paulo Faculdade de Medicina Veterinária e Zootecnia Departamento de Cirurgia Universidade Estadual Paulista Faculdade de Odontologia

Learning Objectives To facilitate widespread utilization of the parathyroid venous sampling, this pictorial assay reviews normal anatomy and its variants of considerable clinical importance. We will also present the problems and challenges they pose for the interventional radiologist. Background Parathyroid venous sampling for para-thyroid hormone (PTH) is a highly promising method for localization and diagnosis of parathyroid tumors. Sampling of small veins is the goal. The reported sensitivity of parathyroid venous sampling is 70-80%. However, patients with congenital variation in anatomy and also those with distorted anatomy due to previous surgery can sometime present significant challenge to successful completion of bilateral parathyroid venous sampling resulting in false negative test. Clinical Findings/Procedure Details Technical Details : This pictoral review presents parathyroid venous anatomy along with the details of catheterization and retrograde venography of the parathyroid venous bed wherever necessary. In the entire series of no significant complication has occurred. Normal Anatomy and Variants : The thyroid venous bed is composed of: (a) a diffusely anastomosing, valveless plexus of veins arising from and investing the thyroid gland; and (b) paired, draining superior, middle and inferior thyroid veins. - Superior thyroid veins - Middle thyroid veins - Inferior thyroid veins - most common patterns - Thymic mediastinal veins - Azygos vein and left superior intercostal veins - Few confusing veins such as anterior jugular and the vertebral veins as well as mediastinal veins. - Interesting cases Conclusion and/or Teaching Points The roentgenographic anatomy of parathyroid veins is presented. As usual with venous anatomy, variations from the preceding standard description are common. Parathyroid drainage occurs predominantly via the inferior thyroid vein. Although inferior thyroid drainage is variable, bilateral samples could be obtained in a high percentage of cases. Probably least important for parathyroid drainage, the superior thyroid was the most constant and predictable of the thyroid veins.

Pulmonary vein thrombosis is a rare but potentially life threatening complication following lobectomy or bilobectomy. We present a case of right upper pulmonary vein thrombosis after a middle and lower lobectomy diagnosed at transoesophageal echocardiography. The patient was treated with antibiotics and anticoagulation with good recovery. Pulmonary angiography was performed 35 days after surgery and revealed the venous return of the right lung through the intercostal veins. Despite double venous drainage of the lungs consisting of bronchial and pulmonary veins, pulmonary to systemic collaterals following pulmonary vein thrombosis have not previously been reported. The development of this shunt can prevent gangrene, and surgical resection of the lung segment involved can be avoided.

Sir, Gasparetto et al. [1] present an interesting case report of a rare anomaly—asymptomatic unilateral pulmonary vein atresia that was confirmed by magnetic resonance angiography. Unlike the case reported at our institution [2], the girl had no symptoms and on follow-up after 5 years she remained asymptomatic. An asymptomatic or mildly symptomatic course of this anomaly could be explained by complexity and pliability of the bronchopulmonary circulation. Liebow [3] showed a double venous drainage in normal human lungs consisting of pulmonary and bronchial veins that intercommunicate between each other. Proximal bronchial veins drain into the azygos, hemiazygos and intercostal veins and pulmonary veins drain into the left atrium. Presumably connections between the pulmonary veins and the caval system via azygos veins are capable of expansion or proliferation in various congenital or acquired pathological conditions. Definitive diagnosis and functional parameters of this anomaly require invasive angiography, but because the girl is asymptomatic, postponement of this procedure could be justifiable. We suggest that increasing availability of cross-sectional techniques (CT, MR) with comprehensive three-dimensional visualization will be used more frequently as a first-line modality to clarify incidental findings. Therefore it is possible that this cardiovascular defect will appear to be not so infrequent.

The superior intercostal veins define the pleural reflections of the caudad extent of the posterior junction line. They are paired structures which drain the first three intercostal spaces and join the azygous on the right and the accessory hemiazygous on the left. Because of their location posterior and lateral to the esophagus and trachea, their pleural reflections may be altered early in the course of a focal nodal disease of the posterior mediastinum.

Persistence of a left superior vena cava is a congenital anomaly of considerable interest but by itself exerts no apparent adverse affect on cardiac function. It may occur as an isolated lesion but more often it is associated with many congenital cardiac anomalies. Heretofore it could only be discovered at autopsy or cadaver dissection, but angiocardiography and cardiac catheterization have made possible its recognition during life. This report is a summary of the findings of 11 cases detected by these methods at this center. Embryology In early development, the cephalic portion of the embryo is drained by bilateral symmetrical right and left anterior cardinal veins. These join the posterior cardinal veins near the heart and form the right and left ducts of Cuvier which enter the sinus venosus (Figure 1A). During the eighth week of fetal life, an oblique communication forms between the anterior cardinal veins and shunts blood from the left yein to the right. This vessel becomes the left innominate vein. The development of the left innominate vein is followed by atrophy of the left anterior cardinal vein. It normally persists as the first left intercostal vein. The left duct of Cuvier persists as the oblique vein of the left atrium which enters the coronary sinus. The latter structure is derived from the left half of the sinus venosus. The right duct of Cuvier normally becomes the superior vena cava (Figure 1B). The fully developed superior vena caval system is demonstrated in Figure 2. If the left innominate vein fails to develop, the left anterior cardinal vein persists and continues to drain the left brachiocephalic veins. In this situation it becomes the left superior vena cava. Since the left duct of Cuvier empties into the left half of the sinus venosus which ultimately becomes the coronary sinus, a persistent left superior vena cava drains into this structure (Figure lB).’-3

A widened mediastinum was found on chest radiography following blunt chest trauma. Aortography alone could not adequately determine the etiology of the radiographic findings; on computed tomography (CT) benign mediastinal widening was confirmed owing to accessory hemiazygous continuation of a left inferior vena cava (IVC), with communication to the left brachiocephalic vein through an enlarged left superior (highest) intercostal vein. This unusual anatomic variant and its radiographic findings are reviewed, as well as the complementary role of CT in the evaluation of the traumatized thoracic aorta and mediastinum.

The right superior intercostal vein is visualised on CT examination as a circular opacity laterally at the right aspect of the vertebral body at the T4-T5 level. In venographic examination the RSIV appears to be formed by the confluence of the venous channels, the right second, third and fourth intercostal veins. In superior vena cava obstruction the RSIV is an important collateral pathway: the flow through the vein depends on the site of the obstruction, anterograde if the obstruction is superior or parallel to the level of the vena azygos, and retrograde if the obstruction is below the vena azygos.

The azygos system (Fig. 282) consists of 3 veins which form longitudinal collecting trunks into which the intercostal veins drain: the azygos (vena azygos major), the hemiazygos (vena azygos minor inferior) and the accessory hemiazygos (vena azygos minor superior). The azygos is located on the right side, and the hemiazygos and the accessory hemiazygos on the left. The right and the left ascending lumbar veins constitute the most caudal portion of the system and drain into the azygos and the hemiazygos, respectively. These veins, because they link together the superior and the inferior venae cavae, constitute important anastomosing channels.

Using a convex array transducer, the advantages and shortcomings of transesophageal real-time two-dimensional Doppler echography (TE2DD) were assessed in a study of the vessels around the esophagus and the stomach in 67 adult patients with (n = 56) or without (n = 11) liver cirrhosis. In most cases, all but the upper- and lowermost margins of the azygos vein could be visualized. The more caudally the portion located, the smaller its diameter and flow velocity became. The average number of intercostal veins visualized by TE2DD was 4 per person. The observable esophagogastric varices seemed to be limited to deeply located ones around the esophagogastric junction. In five patients who had undergone distal splenorenal shunt, splenic venous flow, or shunt flow could be seen from the stomach over a length of about 5 cm. The azygos venous flow in cirrhotic patients was significantly greater than that of patients without cirrhosis. TE2DD appears to be very useful for evaluating flow in the cephalad collateral veins and other vessels around the esophagus and the stomach.

Early and accurate diagnosis of disease—both of malignant and of non-malignant character—involving the bones and blood vessels of the skull, spine and pelvis is of the utmost importance. However, the angiographic visualisation of various pathological conditions within the spine is particularly difficult and on occasion impossible. This is primarily due to the peculiar anatomical and physiological nature of the meningo-rachnoidian venous system (MRVS) (Batson, 1940; Borak, 1942; Bachman and Sproul, 1955; Abrams, 1961). We have developed a new technique for the introduction of a radio-opaque medium intravenously directly into the MRVS through the intercostal veins (Setala, Tarkiainen and Nyyssonen, 1966; Tarkiainen, 1966). The purpose of this paper is to demonstrate the accuracy of the technique in the light of one case randomly selected from our files of about 250 examinations. All surgical and radiographic measures were performed by the authors.

In a dissection performed in our department, we observed multiple variations of the azygos venous system. The hemiazygos vein was absent. The posterior 8th, 9th, and 10th intercostal veins united and their common trunk crossed the vertebral column obliquely lying anterior to the aorta and posterior to the esophagus and opening into the azygos vein at the level of T7-T8 vertebrae. The 7th left posterior intercostal vein also crossed the column anteriorly and joined the common trunk. The present report identifies the variable positions and courses of the veins related to the azygos system. It is important to keep in mind that different courses of the azygos system do exist, so that extra caution is required during surgery of the mediastinum and also in appropriately interpreting the radiographs.

Background The azygos venous system consists of the azygos vein on the right side and the hemiazygos and accessory hemiazygos on the left side. The azygos vein runs through the abdominal cavity along the right side of the vertebral bodies, in a cranial direction, passes through the diaphragm and reaches the mediastinum, where it forms the arch of the azygos which flows into the superior vena cava. Along its course, the azygos vein communicates with the intercostal veins on the right, the hemiazygos vein that collects blood from the left lower intercostal veins, and accessory hemiazygos vein that drains into the left upper intercostal veins. The last two, at the level of the seventh thoracic vertebra, unite and end in the azygos vein. The accessory hemiazygos vein is normally included in the length between T4 and T8. The embryological origin of the accessory hemiazygos vein is the result of an expansion in the direction of the cranial hemiazygos vein, which comes from the left upper sovracardinale vein (Dudiak et al. in Semin Roentgenol 24(1):47–55, 1989; Radiographics 11(2):233–246, 1991; Webb et al. in Am J Roentgenol 139(1):157–161, 1982). Findings This case report describes a rare variant of azygos vein system identified in prenatal diagnosis and confirmed by postnatal ultrasonography. Conclusions The observation of the patient has excluded hemodynamic alterations associated with vascular anomaly.