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A foetal echocardiogram, in a 27-week foetus referred for cardiomegaly, demonstrated dextrocardia, absence of the ductus venosus, and an unrestricted unusual umbilical venous drainage to a left posterior intercostal vein, which continued to left hemiazygos vein and drained into the coronary sinus. Progressive cardiomegaly led to early delivery. To the best of our knowledge, no case with similar umbilical venous drainage has been previously reported.

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.

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.

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.

Spectral analysis of ultrasound radiofrequency backscatter has the potential to identify intercostal blood vessels during ultrasound-guided placement of paravertebral nerve blocks and intercostal nerve blocks. Autoregressive models were used for spectral estimation, and bandwidth, autoregressive order and region-of-interest size were evaluated. Eight spectral parameters were calculated and used to create random forests. An autoregressive order of 10, bandwidth of 6 dB and region-of-interest size of 1.0 mm resulted in the minimum out-of-bag error. An additional random forest, using these chosen values, was created from 70% of the data and evaluated independently from the remaining 30% of data. The random forest achieved a predictive accuracy of 92% and Youden's index of 0.85. These results suggest that spectral analysis of ultrasound radiofrequency backscatter has the potential to identify intercostal blood vessels. (jokling@siue.edu) © 2018 World Federation for Ultrasound in Medicine and Biology.

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.

Paravertebral and intercostal nerve blocks have experienced a resurgence in popularity. Ultrasound has become the gold standard for visualization of the needle during injection of the analgesic, but the intercostal artery and vein can be difficult to visualize. We investigated the use of spectral analysis of raw radiofrequency (RF) ultrasound signals for identification of the intercostal vessels and six other tissue types in the intercostal and paravertebral spaces. Features derived from the one-dimensional spectrum, two-dimensional spectrum, and cepstrum were used to train four different machine learning algorithms. In addition, the use of the average normalized spectrum as the feature set was compared with the derived feature set. Compared to a support vector machine (SVM) (74.2%), an artificial neural network (ANN) (68.2%), and multinomial analysis (64.1%), a random forest (84.9%) resulted in the most accurate classification. The accuracy using a random forest trained with the first 15 principal components of the average normalized spectrum was 87.0%. These results demonstrate that using a machine learning algorithm with spectral analysis of raw RF ultrasound signals has the potential to provide tissue characterization in intercostal and paravertebral ultrasound.

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 aim of this study was to describe the possible variations in the connection between the internal venous vertebral system and the cranial vena cava in rabbit using corrosion technique. The study was carried out on 40 adult New Zealand white rabbits. The venous system was injected by using Batson's corrosion casting kit number 17. We found the connection between the internal venous vertebral system and the cranial vena cava by means of the vertebral veins and the right azygos vein. The vertebral vein was present as independent tributary in 36 cases (90%). In the rest of the cases, it was found as being double, being triple, or forming a common trunk with other veins. The azygos vein was present as independent tributary of the cranial vena cava in 39 cases (97.5%). We found also a common trunk formed by the junction of the deep cervical vein, the right vertebral vein, and the azygos vein in one case (2.5%). The azygos vein received 6, 7, 8, or 9 pairs of dorsal intercostal veins. Documenting the anatomical variations in the rabbit will aid in the planning of future experimental studies and determining the clinical relevance on such studies.

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.

Objective: The purpose of our investigation was to determine the safety and usefulness of embolisation procedures in balloon occluded retrograde transvenous obliteration (BRTO) as treatment of gastric varices after portal hypertension. Materials and Methods: Between June 2004 and August 2009, 40 patients underwent BRTO for gastric varices that occurred after portal hypertension in our institution. When large collateral vessels of gastric varices had developed as drainage veins other than the gastro-renal shunt, these collateral vessels were embolised prior to BRTO. Results: Embolisation was performed for 18 collateral vessels in 16 cases before BRTO. Embolised collateral vessels were the left inferior phrenic vein (n = 14), intercostal vein (n = 3), and ascending lumbar vein communicating with the gastro-renal shunt (n = 1). Mean number of micro-coils used was 5.7 in left inferior phrenic veins, 4.7 in intercostal veins and 4 in the ascending lumbar vein. In 36 (90%) patients, contrast-enhanced abdominal CT after BRTO showed that the gastric varices were well obliterated. The rate of occurrence of cases in which the remnant of the enhanced area in the gastric varices was seen even after BRTO was statistically higher in cases requiring embolisation of collateral vessels than in those who did not (4/16 versus 0/24, P = 0.0199 according to Fisher's exact probability test). Recurrence of gastric varices was determined by endoscopy in 1 (2.5%) case necessitating embolisation of collateral vessels. There were no serious complications. Conclusion: Embolisation of collateral vessels before BRTO is a safe and useful procedure. However, especially in cases having collaterals sufficiently large to require embolisation, careful follow-up for recurrence of gastric varices is necessary.

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.

A n asymptomatic intercostal arteriovenous fistula was suspected because of a faint midthoracic intercostal bruit detected during auscultation in a 3-year-old girl with common cold. There was no history of trauma, iatrogenic therapeutic procedures, or congenital abnormality. Multislice contrast-enhanced computed tomography of the thorax revealed an engorged T8 intercostal artery arising from the thoracic aorta, engorged intercostal vein, and engorged intervertebral vein (Figures 1-3; Figures 1 and 3 available at www.jpeds.com). A three dimensional volume-rendered lateral oblique image confirmed the engorgement of the T8 intercostal artery arising from the thoracic aorta and the engorgement of the intercostal vein (Figure 4; available at www.jpeds.com). Based on the imaging and clinical findings, the diagnosis of congenital intercostal arteriovenous fistula was made. The patient underwent uneventful coil embolization. Intercostal arteriovenous fistulas and malformations are rare lesions, and only a few cases have been published. Most of them occur secondary to trauma or iatrogenic therapeutic procedures and in association with neurofibromatosis type 1, although a congenital origin is suggested in extremely rare cases. Clinical manifestations vary according

Objective The superior vena cava (SVC) obstruction by malignant diseases is either by direct invasion and compression or by tumour thrombus of the SVC. Whatever is its cause, obstruction of the SVC causes elevated pressure in the veins draining into the SVC and increased or reversed blood flow through collateral vessels. Severity of the syndrome depends on the collateral vascular system development. Therefore, imaging of the collateral veins with variable location and connection is important in determining the extension and management of the disease. Our aims are to describe collateral vessels of the superior vena cava syndrome (SVCS) related with the malignant diseases and to assess the ability of multi-detector row CT with multiplanar and 3D volume rendering techniques in determining and describing collateral circulations. Materials and methods We present CT angiography findings of seven patients with small cell carcinoma of the lung (n = 2), squamous cell carcinoma of the lung (n = 3), Hodgkin disease of the thorax (n = 1), and squamous cell carcinoma of the oesophagus (n = 1). The patients received contrast-enhanced CT scans of the chest and abdomen on a multi-detector row CT during breath holding at suspended inspiration. Results CT images revealed the cause and level of the SVC obstruction in all patients with axial and multiplanar reconstructed images. The SVC showed total obstruction in five patients and partial obstruction in two patients. The most common experienced collateral vessels were azygos vein (6), intercostal veins (6), mediastinal veins (6), paravertebral veins (5), hemiazygos vein (5), thoracoepigastric vein (5), internal mammary vein (5), thoracoacromioclavicular venous plexus (5), and anterior chest wall veins (5). While one case showed the portal-systemic shunt, V. cordis media and sinus coronarius with phrenic veins were enlarged in two cases, and the left adrenal vein was enlarged in a patient. In one case, the azygos vein with reversed blood flow was drained into both inferior vena cava and hemiazygos vein with the left renal vein. Conclusion Multi-detector row CT with multiplanar and 3D imaging is an effective tool in evaluation of the SVCS and has a greater advantage than the other imaging techniques. 3D volume rendering is a useful technique in determining and describing collateral circulations in addition to the primary disease process.

Background/Purpose Some children dependent on total parenteral nutrition for long periods have no more axillary, internal jugular, external jugular, saphenous, and femoral veins available for cannulation. In such patients, the central venous system can still be accessed via the azygos vein by placing an implantable port catheter through one of the right posterior intercostal veins. This is the first known description of such procedure. Methods We report the use of the second and third right intercostal veins for placement of the catheter by right intrapleural thoracotomy in 2 pediatric patients with short gut syndrome. Results Recovery from the thoracotomy was uncomplicated, and the patients could receive complete intravenous nutritive mixtures immediately after the insertion of the catheter. Both patients remain dependent on total parenteral nutrition and are awaiting an intestinal transplantation. Conclusion The knowledge of alternate routes to obtain central venous access for prolonged parenteral nutrition is critically important, and the azygos system can be used when more accessible veins are unavailable.

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.

The arteries and veins of the left vagus (VN) and left recurrent laryngeal (RLN) nerves from the thoracic inlet to the subaortic region are described following vascular casting with red colored latex in 6 adult fresh non-embalmed cadavers. In all specimens the anterior bronchoesophageal artery supplied at least one vessel to the VN and RLN in the subaortic region. For the RLN other arterial sources were arteries arising from the aortic arch in 1 specimen, the subclavian artery in 3 specimens, the first intercostal artery in 1 specimen, and the inferior thyroid artery in all specimens. For the VN other arterial sources were arteries arising from the aortic arch in 2 specimens and the inferior thyroid artery in 1 specimen. For both the VN and RLN the veins were located under the pleura and directed towards the internal thoracic vein anteriorly and the thoracic intercostal veins posteriorly. In conclusion, the inferior thyroid artery at the thoracic inlet for the RLN and the anterior bronchoesophageal artery are the more consistent vessels supplying the VN and RLN. Vascular damage occurring during mediastinal lymph node excision to the VN and RLN, especially in the subaortic region, may explain postoperative vocal fold paralysis.

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.

Spontaneous hemothorax in the left pleural space occurred suddenly in a patient with thrombotic thrombocytopenic purpura (TTP). In spite of massive blood transfusion, the hemorrhage could not be stopped. The patient suffered shock due to tension hemothorax and hypovolemia, resulting in cardiac arrest. After successful cardiopulmonary resuscitation, surgical hemostasis was performed. The main cause of the bleeding was rupture of the left intercostal vein. TTP is a severe microvascular occlusive thrombotic microangiopathy that can induce congestion, vasculitis, and ischemia. This mechanism is thought to have been involved in the rupture of the intercostal vein in the present patient.

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).

We report the case of a neonate born at 384/7 weeks of gestation with median birth weight and size and in the 75th percentile for head circumference. Routine pregnancy follow up allowed the antenatal discovery of azygos continuation with absence of the inferior vena cava.

A 28-year-old man with a persistent cough and a mild fever was transferred to our institution. Computed tomography angiography showed a giant azygos venous aneurysm associated with the dilation of lumbar veins, azygos veins, hemiazygos veins, and intercostal veins (A-D). At the ages of 3 and 18 years, the man had undergone resection of angiomas in the chest wall (approximately 8 8 7 cm) and on the back (approximately 10 8 8.5 cm), respectively. The pathologic diagnosis showed cavernous hemangioma and lymphangioma. After the second operation, he was subsequently injected with ureaphil every 3 months for 18 times in total. However, the computed tomography scan at that time did not show the visible dilation of azygos veins and fertile varicose veins including intercostal veins, lumbar veins, and partial visceral veins, which was significantly different from that of 10 years later. Azygos venous aneurysms are extremely rare. Nakamura et al reported three main types of azygos venous aneurysms caused by different factors. One of them was dilation of the azygos vein induced by increased venous pressure and volume load, as in the cases of heart failure, portal hypertension, right atrial mural thrombosis, and inferior vena caval occlusion. In this case, we believe it was induced by resection of hemangioma, which increased pressure and volume load. To the best of our knowledge, the giant azygos venous aneurysm caused by resection and embolization of cavernous hemangioma in the chest wall and back has never been reported. Azygos venous aneurysms may also be related to traumatic pseudoaneurysm and idiopathic saccular aneurysm. Its differential diagnosis should include other posterior mediastinal masses. However, Gomez et al reported that if it is thrombosed, surgical therapy is necessary to prevent pulmonary embolism. A video-assisted thoracoscopic excision is recommended as the best technique.

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.

The complexity of the anatomy of the sympathetic trunk and intercostal veins in the third and fourth intercostal space may lead to intraoperative or postoperative bleeding. The purpose of this study was to investigate the anatomical variations of the sympathetic trunk and intercostal veins in the third and fourth intercostal spaces. The size and crossing type of veins in the third and fourth intercostal spaces in 44 Korean patients with palmar hyperhidrosis were analyzed. We classified intercostal veins by their size (small, medium, and large) and crossing type (anterior or posterior to sympathetic nerve). Large intercostal veins susceptible to bleeding were found in 36.4 and 68.2% of patients in the right third and fourth intercostal spaces, respectively and in 2.3 and 4.5% of left third and fourth intercostal spaces, respectively. More than 80% of the left third and fourth intercostal veins were small. Anterior crossing intercostal veins, which often cause problems at the third and fourth right intercostal spaces, were found in 27.3% (third) and 15.9% (fourth). However, there were only two cases of anterior crossing veins on the left side. Large anterior crossing veins were found only on the right side. In conclusion, surgical procedures of the right sympathetic ganglia may have increased risks due to a higher frequency of large anterior crossing intercostal veins. Careful dissection is necessary to decrease the incidence of intraoperative or postoperative bleeding.

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.

The uppermost portion or arch of the azygos vein is frequently ligated and divided in thoracic surgery. The hemodynamic effects arising from this proce dure have not, however, been described previously. The authors assessed such effects by using transesophageal real-time two-dimensional Doppler echography (TE2DD). Nine patients, whose azygos arch had been ligated and divided in the course of surgery for lung cancer, were examined. The intervals between the prior operation and the examination with TE2DD ranged from one to fifty months. By use of a convex array transducer with a frequency of 7.5 MHz, the hemodynamics of both the azygos vein and the intercostal veins, which join the former, were assessed. The esophagopetal portion of the azygos vein could be visualized in color in 6 of 9 cases. In all these 6 cases, the flow direction of the azygos vein was reversed and directed caudally. Blood flow in both the azygos vein and the intercostal veins is normally pulsatile. After ligation, however, it had become constant in 3 of 5 cases analyzed by pulsed Doppler spectrum. The value of mean flow velocity in the azygos vein (9 ± 5 cm/sec) was significantly (p < 0.05) smaller than that of the control group (15 ±5 cm/sec).

A new preparation is described for the study of the microcirculation of the rat diaphragm by in vivo microscopy. After midline laparotomy, the abdominal site of the diaphragm muscle was exposed. The rat was mechanically ventilated and placed in the Trendelenburg position, thus allowing a microscope placed on a three-dimensional articulated system to be set up perpendicular to the diaphragm. The diaphragm was then transilluminated by inserting fiberoptic microprobes into the thorax acvity by thoractomy in the fifth intercostal space. This preparation allowed us to describe the morphological characteristics of the arteriolar network in vivo. As regards the venular network, two parts were distinguished: one part collects the blood of the external half of the diaphragm, runs roughly parallel to the arterioles, and converges toward the internal mammary and intercostal veins; the other part collects the blood of the central half of the diaphragm and converges on the central venous arcade along its central tendon. Anastomotic channels between these two parts were observed, as well as spontaneous inversion of the direction of the blood flow, indicating the presence of unsteady pressure gradients in some branches of the venular network. Capillary density was also studied by measuring intercapillary distance, whose mean value was 21.43 ± 0.67 μm. No differences in intercapillary distance were found between the external and central parts of the diaphragm. In conclusion, we describe a preparation which allowed us to study the diaphragmatic microcirculation for at least 2 hr under good hemodynamic conditions. The study of this specific microcirculation is important because the diaphragm's metabolism and functions are specific and because it is essential to life that its perfusion should be adapted to its specific metabolic requirements.

innominate and intercostal veins. PTH gradients assist in localization of parathyroid adenomas. A correlation between surgical pathology and parathyroid venous sampling is made. Conclusion and/or Teaching Points: Parathyroid venous sampling is an effective tool in the evaluation of parathyroid adenoma, particularly in the setting of hyperparathyroidism and negative non-invasive imaging. Interventional radiologists should become familiar with this procedure as it may be a last resort imaging modality.

Spontaneous massive haemothorax is rare. We describe a healthy 44 year old woman who experience sudden onset chest pain while sleeping. Chest radiograph revealed massive right pleural effusion. Progressive dyspnoea, cold sweating, and tachycardia developed later. A tube thoracostomy was performed immediately and massive haemothorax was noted. An emergency thoracotomy was performed because of unstable vital signs. Disruption of the right third intercostal vein with continuous bleeding was observed, and suture ligation of the vein was performed. The total blood loss was about 4000 ml. The patient recovered uneventfully, and her condition at follow up visits to the outpatient department was satisfactory.

A case of posterior mediastinal panniculitis is reported. CT and MRI showed a paraspinal mass containing a small amount of fat. The intercostal veins were found to run through the mass without being distorted, mimicking lymphoma. The diagnosis of panniculitis was made by CT-guided biopsy and open biopsy.

We illustrate the spectrum of venous collateral pathways caused by the thoracic central venous obstruction with direct spiral computed tomography (CT) venography and 3-dimensional reconstruction images. Venous structures that can be demonstrated with CT venography include the jugular veins; the subclavian and brachiocephalic (innominate) veins; the internal and lateral thoracic veins; the superior and inferior venae cavae; the pericardiophrenic veins; the azygos, hemiazygos, and accessory hemiazygos veins; and the intercostal veins.

Multi-detector row computed tomography (CT) and volume rendering can be used as an interpretive aid to present the systemic and pulmonary venous anatomy of the thorax. Both of these venous systems are routinely imaged in clinical practice and are important in interpretation of diagnostic images in health and disease. Multi-detector row CT and three-dimensional volume rendering provide high-quality near-isotropic data (ie, the longitudinal resolution approximates the in-plane resolution). The data sets allow tailored postprocessing to produce images optimized for these vessels, which are often not fully appreciated at planar axial imaging alone. Venous structures of the thorax that can be demonstrated with multi-detector row CT and volume rendering include the jugular veins; the subclavian and brachiocephalic veins; the internal and lateral thoracic veins; the superior and inferior venae cavae; the coronary sinus, the cardiac and pericardiophrenic veins, and vein grafts; the azygos, hemiazygos, and accessory hemiazygos veins; the intercostal veins; the pulmonary veins; and other thoracic veins.

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.

Lung perfusion imaging with Tc-99m MAA was performed in a patient thought to have pulmonary embolism. The dynamic flow images obtained before static lung perfusion imaging showed delayed drainage of the tracer into the right brachiocephalic vein and superior vena cava, and unusual demonstration of the right lateral thoracic and intercostal veins as collateral pathways. It was thought that coughing at the time of bolus injection of the tracer into a right antecubital vein caused an increase of intrathoracic pressure and consequently disturbed the venous return to the thorax.

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.