Posterior Intercostal Veins Research Articles

Morphologic variations of the superior intercostal vein: An anatomical study with clinical applications.

This study aimed to validate and compare the anatomical variations of the superior intercostal veins, focusing on their origin, course, anastomoses, and destination. In addition, the results were compared with findings from other relevant studies. Fifty Korean and 16 Chinese adult cadavers were dissected for this study. The superior intercostal veins were dissected and measured. In our study of 66 specimens, the right superior intercostal vein was observed in 92.3% of cases, while the left superior intercostal vein was observed in 50%. The right superior intercostal vein was subdivided into six types based on its composition, which mainly drained the second and third right posterior intercostal veins. Similarly, the left superior intercostal vein was subdivided into eight types, primarily involving the second to fourth left posterior intercostal veins. This detailed anatomical study successfully identified and classified the various morphologic types of the superior intercostal vein and reviewed the clinical significance of this vein. The findings of this study can offer valuable anatomical evidence to physicians, aiding in their understanding and utilization of the superior intercostal vein.

A unique presentation of anomalous posterior intercostal veins, hemiazygos vein and left superior vena cava

The venous anomalies of thorax are common, but the only drainage of 1st and 2nd posterior intercostal veins on both sides into the internal vertebral venous plexus with no communication to the azygos system is reported for the first time. The common hemiazygos vein is singular receiving all the posterior intercostal veins on the left from 4th to the 11th with subcostal on the left side. This vein drains into azygos on the right. It also connects on the cranial end via an anomalous vein to the Left SVC. This anomalous vein also receives the left 3rd posterior intercostal vein. On the right, the azygos system is normal.

Unusual Course of Posterior Intercostal Vein at the 3rd Intercostal Space – A Case Report

The posterior intercostal veins drain the thoracic wall and lie in the costal grooves along with the intercostal arteries and nerves posterior to the thoracic sympathetic chain. During routine dissection of the posterior mediastinum of a formalin-fixed male cadaver in the Anatomy department of an undergraduate and postgraduate teaching medical college in India, a large-sized posterior intercostal vein was identified crossing anterior to the thoracic sympathetic chain at the level of the 3rd intercostal space on the right side. The presence of such variation may hinder the surgical procedure of the posterior mediastinum and will pose an increased risk of intraoperative or postoperative bleeding. Knowledge of such variation is necessary to avoid laceration of the posterior intercostal vein, which is the potential cause of bleeding in the region of the thorax.

Study of Various Patterns of Azygos Venous System and its Clinical Significance

Background: The azygos system includes those veins which are straight in course, paravertebral in positionand not accompanied with the corresponding arteries. The azygos vein may arise as lumbar azygos veinfrom the back of inferior vena cava or by the union of right subcostal and right ascending lumbar veins. Itenters the thorax, receives lower 8 right posterior intercostal veins, superior intercostal vein, hemiazygosand accessory hemiazygos veins and ends by joining the superior vena cava. The hemiazygos vein is formedon the left in a manner similar to that of azygos vein. The aim of the present study was to investigate thevarious patterns of the azygos venous system.Methods: A total number of 30 cadavers were studied and were evaluated based on the study of Anson BJand Mcvay CB.Conclusion: Out of 30 specimens studied, 17 (56%) specimens showed normal pattern, 5 (16%) specimensshowed caterpillar pattern and rest 8 (26%) specimens showed ladder pattern.Azygos system of veins serve as an alternative drainage channel between superior vena cava and inferiorvena cava in case of obstruction. The knowledge of various patterns could be useful for radiologists andsurgeons to prevent intra-operative hazards.

Usual and Unexpected Variations in the Veins of the Posterior Abdomen: A Case Study

Two venous system components comprise the drainage of the posterior abdominal cavity. One component drains blood from the visceral derivatives of the urogenital ridge (e.g., kidneys, gonads) directly to the inferior vena cava (IVC). The other venous system collects blood from the body wall and drains into the azygos system through the subcostal vein, ascending lumbar vein, and lower posterior intercostal veins. Veins, and especially the azygos system, are notoriously variable. Much of this variability arises from the complex embryological development of the caval venous system in the thoracic and abdominopelvic cavities; but the formation of venous anastomoses representing multiple routes of drainage from a single region also contribute to the variability of veins.During routine dissection of the abdomen of a male cadaver (Caucasian, 67 years), the right testicular vein demonstrated multiple anatomical variations. An anomalous vein arising from several small tributaries at the lateral end of the 11th and 12th ribs was discovered during the dissection. This vein crossed the posterior abdominal wall inferomedially to drain into the right testicular vein. Further exploratory dissection revealed direct communication between the anomalous vein and the right 11th posterior intercostal vein, which could be traced from the origination of the anomalous vein to the connection with the azygos vein at the appropriate vertebral level. The anomalous vein represents an unusual route for collateral venous circulation between the azygos system and the caval system in the abdomen via the right 11th posterior intercostal vein. Additionally, the right testicular vein drained into the right renal vein instead of directly draining into the IVC. No other notable variations were observed in the abdominal vasculature. The left testicular vein, left renal vein, left posterior intercostal veins, and left subcostal vein all demonstrated typical merging patterns. Accompanying renal, testicular, and posterior intercostal arteries on the right side also appeared to have normal branching patterns.

An Innovative Case Report: Obesity and Portal Hypertension

BackgroundObesity is a growing epidemic in the United States, affecting an increasing proportion of the adult population. It’s become increasingly important that healthcare professionals are adequately educated about the multi‐faceted nature of obesity in order to best serve their obese patients. It’s crucial that health professions students understand the pathophysiology of obesity, as well as common comorbidities associated with the chronic nature of obesity. There is a strong relationship between obesity and Non‐Alcoholic Fatty Liver Disease, which may lead to cirrhosis of the liver with resultant portal hypertension. Here we apply an innovative teaching method to present a case report for an obese donor with a medical history including cirrhosis of the liver and renal failure. This module is designed to engage and educate health professions students in a way that will have a lasting impact on their appreciation for the health risks of obesity.MethodsTaking an innovative approach, we completed dissection of an obese donor with known history of cirrhosis of the liver. This dissection was documented with photography and video demonstrations. These images were used as a visual hook for a SoftChalk educational module focused on portal hypertension as a comorbidity of obesity. This module includes lecture material, quizzes, as well as photographic and video demonstrations to allow students to visualize the effects of obesity on the liver and portal venous system.ResultsThrough dissection of the obese donor, we were able to visualize an enlarged liver which supports the diagnosis of underlying liver disease. In the vascular system, we were able to visualize an enlarged Superior Mesenteric vein and Splenic vein, the two veins that form the Hepatic Portal vein. An enlarged spleen was also visualized, which may be expected due to Splenic vein congestion. The Azygos system of veins and posterior intercostal veins were also dilated, as well as various superficial abdominal veins. These dilated veins allow for students to visualize the compensations of portal‐caval anastomoses in response to portal hypertension.ConclusionsThe use of obese donors is innovative in that most programs avoid use of morbidly obese donors in the gross anatomy lab, therefore most students have never had a chance to appreciate what morbid obesity looks like (it is not a cosmetic issue). In addition to the educational value of the project, this project affords the opportunity to honor the wishes of obese donors who wish to donate their body to medical education. This educational module allows for a visual learning experience highlighting the relationship between obesity and portal hypertension, which can be utilized as supplemental material in a variety of medical school courses, such as Gastrointestinal and Cardiovascular pathology‐based courses as well as Medical Gross Anatomy. Future directions include expanding the number of modules available, and systematically evaluating the effectiveness of the modules before integrating them into multiple courses. This approach may help advance obesity education in order to best serve patients diagnosed with obesity.

Rare anatomical variation of the azygos system

This study presents a rare case of azygos vein agenesis associated with hemiazygos vein agenesis. The observed anatomical variation consists in the existence of a large venous trunk located entirely to the left of the midline that receives drainage from the right and left posterior intercostal veins and drains into the superior vena cava by means of an arch. No vein in typical azygos or hemiazygos vein topography was observed. This anatomical variation may lead to clinical and hemodynamic repercussions, while also presenting anatomical and radiological importance regarding surgical planning concerning posterior mediastinal structures.

Are single-injection erector spinae plane block and multiple-injection costotransverse block equivalent to thoracic paravertebral block?

Thoracic paravertebral block (TPVB) is considered the gold standard for hemithoracic regional anaesthesia. Erector spinae plane block (ESPB) is a new posterior thoracic wall block. Multiple-injection costotransverse block (MICB) mimics TPVB but with injection points within the thoracic intertransverse tissue complex and posterior to the superior costotransverse ligament. We aimed to compare the spread of injectate into the thoracic paravertebral space (TPVS) resulting from single-injection ESPB and MICB, respectively, with TPVB. Ten soft-embalmed cadavers were utilised. In five cadavers, the right hemithorax was randomly allocated either to ultrasound-guided single-injection ESPB or single-injection TPVB; vice versa on the other side. In another five cadavers, the right hemithorax was randomly allocated either to ultrasound-guided MICB or multiple-injection TPVB. About 20mL of dye was injected in each hemithorax with all techniques. With TPVB, the dye was consistently present in the TPVS with concomitant epidural spread in the majority of cases. The injectate spread into the TPVS with ESPB (60%) and MICB (100%). MICB consistently stained the ventral rami (T1-7), communicating rami and thoracic sympathetic trunk without epidural spread. Dissection after MICB revealed dye spread into the TPVS via the costotransverse foramina and along the dorsal branches of the posterior intercostal veins. Consistent spread of dye into the TPVS colouring the ventral rami, the communicating rami, and the sympathetic trunk was observed with MICB; in this respect equivalent to TPVB. ESPB exhibited only partial success and was not equivalent to TPVB. No epidural spread was found with neither MICB nor ESPB.

A rare variation of the hemiazygos vein draining into the persistent left superior vena cava

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.

Prominent Accessory Hemiazygos Vein representing Persistence of Cranial Portion of Posterior Cardinal Vein: Embryological Variant

ABSTRACT Introduction The azygos venous system has developed from the postcardinal veins of the embryo, and small parts persist only at the commencement of the azygos vein. Complex embryological development of these veins is a major cause for many possible variations of the azygos system. Materials and methods The present study was done in the Department of Anatomy, Government Medical College, Amritsar, on a male cadaver aged about 50 years. The thoracic cavity was opened to dissect the azygos system of veins. Results The system showed the persistent cranial part of the posterior cardinal vein. This led to the formation of a well-developed venous channel on the left side of the aortic arch and the thoracic aorta. This channel drained the 2nd to 10th left posterior intercostal veins and drained itself into the left brachiocephalic vein (LBV) after crossing the arch of aorta vertically on its right. There was no transvertebral communication between this channel and azygos vein on the right side. The hemiazygos vein (HAV) on the left side was normally formed and immediately drained into the azygos vein by turning to the left. The azygos vein on the right side was also normal. Conclusion The presence of such persistent embryological remnant, its position, and approximation to the structures near the arch of aorta should be taken into account to avoid radiological misdiagnosis and surgical complications. How to cite this article Sehmi S. Prominent Accessory Hemiazygos Vein representing Persistence of Cranial Portion of Posterior Cardinal Vein: Embryological Variant. Curr Trends Diagn Treat 2017;1(1):40-41.

Multiple variations of azygos system of veins: a case report

AbstractAzygos 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.

A rare variant between the left superior vena cava and the azygos vein

During the educational dissection of a 68-year-old Chinese male cadaver, an azygos vein (AV) coursing on the left side with double superior vena cava was observed. The left superior vena cava (LSVC) began from the confluence of the left internal jugular and left subclavian veins, and extended downwards medially into the left edge of the dilated coronary sinus. The right superior vena cava was formed by the union of the right internal jugular and right subclavian veins, and drained into the right atrium from the above. The AV was formed by the union of the right and left ascending lumbar veins at the level of the tenth thoracic vertebra. It ascended along the left margin of the thoracic vertebra, receiving almost the bilateral posterior intercostal veins and then extended into the LSVC on the left wall via the azygos arch. Better understanding of these variations will reduce unnecessary and potential harmful testing, and unneeded patient anxiety.

A clinical approach to brown adipose tissue in the para-aortic area of the human thorax.

BackgroundHuman thoracic brown adipose tissue (BAT), composed of several subdivisions, is a well-known target organ of many clinical studies; however, the functional contribution of each part of human thoracic BAT remains unknown. The present study analyzed the significance of each part of human thoracic BAT in the association between regional distribution, cellularity, and factors involved in the functional regulation of thoracic BAT.MethodsWe analyzed 1550 healthy adults who underwent medical check-ups by positron-emission tomography and computed tomography (PET–CT) imaging, 8 cadavers, and 78 autopsy cases in an observational study. We first characterized the difference between the mediastinum and the supraclavicular areas using counts of BAT detection and conditions based on PET–CT outcomes. The measurable important area was then subjected to systematic anatomical and immunohistochemical analyses using anti-uncoupling protein 1 (UCP1) antibody to characterize the cellularity in association with age and sex.ResultsIn PET–CT scanning, the main site of thoracic BAT was the mediastinum rather than the supraclavicular area (P < 0.05). Systemic macroanatomy revealed that the thumb-sized BAT in the posterior mediastinal descending para-aortic area (paBAT) had feeding vessels from the posterior intercostal arteries and veins and sympathetic/parasympathetic innervation from trunks of the sympathetic and vagus nerves, respectively. Immunohistochemical analysis indicated that the paBAT exhibited immunoreactivity for tyrosine hydroxylase and vesicular acetylcholine transporter located in the pericellular nervous fibers and intracellular UCP1. The brown adipose cells of paBAT showed age-dependent decreases in UCP1 expression (P < 0.05), accompanied by a significant increase in vacuole formation, indicating fat accumulation (P < 0.05), from 10 to 37 years of age (P < 0.01).Conclusions paBAT may be one of the essential sites for clinical application in BAT study because of its visible anatomy with feeding vessels and sympathetic/parasympathetic innervation functionally affected by outer condition and senescence.

Variety and Delicacy of Animal Mechanism

Editor-in-Chief Clinical Anatomy, Birmingham, AlabamaFontenelle has said, “Astronomy and anatomy arethe studies which present us with the most strikingviews of the two great attributes of the SupremeBeing. The first of these fills the mind with the ideaof his immensity, in the largeness, distances, andnumber of the heavenly bodies; the last astonishes,with his intelligence and art in the variety and deli-cacy of animal mechanism” (Nicholson, 1819).Herein, we certainly address the “variety and deli-cacy of animal mechanism.” Among others, thisissue of Clinical Anatomy offers original studiesaimed at comparing surgical approaches to the pet-rous apex, radiologic studies of the knee and spine,new findings regarding potential thermoregulationand the posterior intercostal veins and both a his-toricreviewofBenjaminAlcockandhiscanalandanew teaching approach to the perineum. As always,we welcome your comments and suggestions onhow we can improve our journal.

The posterior intercostal vein: A thermoregulatory gateway to the internal vertebral venous plexus

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.

Variation of hemiazygos vein with absence of accessory hemiazygos vein - a dissection study

AbstractHemiazygos vein and Accessory hemiazygos vein lie on the left side in the posterior mediastinum of thorax and are the counterpart of azygos vein on right side. During routine cadaveric dissection of thoracic region in an adult male, we found an abnormal venous channel which was single and was lying on the left side of the vertebral column. It received tributaries from superior intercostal vein and posterior intercostal veins. We found this abnormal venous channel draining directly into left brachiocephalic vein in contrast to its usual drainage into azygos vein. Hence this can be considered as abnormal venous channel and variant of hemiazygos vein and accessory hemiazygos vein. The azygos and hemiazygos venous system is commonly encountered during surgical intervention performed on posterior thoracic wall. This case report provides a new data of potential clinical significance.

Garland Vein: Sequela of Left Innominate Occlusion

The accessory hemiazygos vein is an infrequently visualized channel that normally drains the posterior intercostal veins of the left midthorax, but can maintain critical venous return following innominate occlusion. In a 47-year-old woman, severe left innominate vein stenosis (Fig 1, arrow) occurred after an ipsilateral central venous catheter had been in place for 7 months. A peculiar garland-shaped venous configuration resulted from a grossly dilated accessory hemiazygos vein maintaining jugular and subclavian flow into the right atrium via the azygos vein, enabled by a tortuous hemiazygos-subclavian anastomosis (course demonstrated by guide wire in Fig 2, arrows).

Venous air embolism in consecutive balloon kyphoplasties visualised on CT imaging

We noted a large amount of intravenous gas during balloon kyphoplasty on CT imaging. Formal assessment to understand the extent, possible causes and implications was undertaken. Ten consecutive cases of balloon kyphoplasty were performed under general anaesthesia in the prone position, on a single vertebral level using a two-step technique under combined fluoroscopic and CT guidance. CT of the affected vertebra was performed before, after, and intermittently during the procedure. In 2 cases delayed CT was carried out in the supine position. Gas was seen on CT imaging, but not on conventional fluoroscopy. The gas is most likely to be air introduced during the procedure and was seen in the epidural and paravertebral venous plexus, posterior intercostal veins, renal veins, IVC and azygos vein. The average measured volume of gas seen on the post-procedure CT imaging was 1.07 mL, range 0.16-3.97 mL. There was no correlation of the measured amount of gas to the procedure duration or location, the use of a curette or the injected cement volume. Delayed CT in the supine position no longer showed air in the local venous system. Balloon kyphoplasty is associated with the fluoroscopically invisible introduction of air into the vertebral and paravertebral veins and deep systemic veins and is likely to be much more extensive than identified on CT imaging. There is potential for serious air embolism in kyphoplasty and if there is a sudden deterioration in patient condition during the procedure the possibility of this complication needs to be considered.

Anomalous azygos venous system in a south Indian cadaver: a case report.

The posterior thoracic wall, an area drained by the azygos venous system, is a common site for surgical intervention. Since the venous part of the cardiovascular system is subject to most common variation, abnormalities in the azygos venous system are often reported. During routine dissection classes for undergraduate medical students, we encountered a variation in the azygos venous system in a 65 years old south Indian male cadaver. We observed that there was no accessory azygos vein, and left 4th, 5th, 6th and 7th posterior intercostal veins terminated directly into azygos vein. Identifying these types of variations is important during imaging this region and surgical operations of mediastinum.

Anomalous azygos venous system in a south Indian cadaver: a case report

IntroductionThe posterior thoracic wall, an area drained by the azygos venous system, is a common site for surgical intervention. Since the venous part of the cardiovascular system is subject to most common variation, abnormalities in the azygos venous system are often reported.Case presentationDuring routine dissection classes for undergraduate medical students, we encountered a variation in the azygos venous system in a 65 years old south Indian male cadaver. We observed that there was no accessory azygos vein, and left 4th, 5th, 6th and 7th posterior intercostal veins terminated directly into azygos vein.ConclusionIdentifying these types of variations is important during imaging this region and surgical operations of mediastinum.