The mediastinum, mediastinum, is a complex of organs located in the chest cavity between the right and left pleural cavities. In front, the mediastinum is bounded by the sternum; behind - thoracic vertebrae; from the sides - the right and left mediastinal pleura; above, the mediastinum extends to the upper aperture of the chest, below to the diaphragm (Fig. 247, 248). The mediastinum is located in the sagittal plane not symmetrically, but deviates to the left in connection with a certain position of the heart. The organs that make up the mediastinum are interconnected by loose tissue.

The greatest clinical significance is the division of the mediastinum into anterior and posterior, mediastinum anterius et posterius. They are separated by a frontal plane, conventionally drawn through the trachea and the roots of the lungs (see Fig. 247).

The organs of the anterior mediastinum include the heart with the pericardial sac and the beginning of large vessels, the thymus gland (or an accumulation of adipose tissue replacing it in an adult), phrenic nerves, pericardial-phrenic vessels, internal thoracic blood vessels, peri-sternal, anterior mediastinal and upper diaphragmatic nodes.

In the posterior mediastinum are the trachea and the main bronchi, the esophagus, the thoracic part of the descending aorta, the thoracic lymphatic duct, the unpaired and semi-unpaired veins, the right and left vagus and viscera

nerves, sympathetic trunks, posterior mediastinal, prevertebral, peritracheal, tracheobronchial and bronchopulmonary lymph nodes.

Recently, the mediastinum has been conventionally divided into two sections: the upper mediastinum and the lower mediastinum. The border between them is drawn along a conventional horizontal plane running from the lower edge of the sternum handle to the intervertebral disc between the IV and V thoracic vertebrae.

In the upper mediastinum, mediastinum superius, the thymus gland, large cardiac vessels, vagus and phrenic nerves, the sympathetic trunk, the thoracic lymphatic duct, and the upper part of the thoracic esophagus are located.

In the lower mediastinum, mediastinum inferius, in turn, the anterior, middle and posterior mediastinum is isolated.

The anterior mediastinum, mediastinum anterius, is located between the body of the sternum in front and the front of the costal pleura in the back. It contains the internal mammary vessels; pericardial, anterior mediastinal and pre-pericardial lymph nodes.

The middle mediastinum, mediastinum medius, corresponds to the location of the heart with the pericardium, large cardiac vessels and roots

lungs The phrenic nerves also pass here, accompanied by diaphragmatic-pericardial vessels and the lymph nodes of the lung root

The posterior mediastinum, mediastinum posterius, 01 is bounded by the wall of the pericardium in front, the thoracic spine and the ribs behind The organs of the posterior mediastinum include the thoracic part of the descending aorta, unpaired and semi-unpaired veins, right and left sympathetic trunks, vagus, internal nerves, thoracic middle lymphatic ducts the lower part of the thoracic esophagus, posterior mediastinal and prevertebral lymph nodes.

3. Basal subcortical nuclei of the brain. Internal capsule, its localization, pathways.

TOPOGRAPHY OF THE MEDIUM ORGANS

The purpose of this study guide is to outline the interposition of the organs of the chest cavity, to highlight topographic features that are of interest for making a clinical diagnosis, and also to give an idea of \u200b\u200bthe main surgical interventions on the mediastinal organs.

MEDIUM - the part of the thoracic cavity located between the thoracic vertebrae in the back, the sternum in front and two leaves of the mediastinal pleura laterally. From above, the mediastinum is limited by the upper aperture of the chest, from below by the diaphragm. The volume and shape of this space changes during breathing and due to the contraction of the heart.

In order to facilitate the description of the interposition of individual organs in different parts of the mediastinum, it is customary to divide it into parts. Moreover, due to the fact that there are no objective anatomical and physiological boundaries between these parts, in various literary sources this is done in different ways.

In separate textbooks on systemic and topographic anatomy, two mediastinums are distinguished: anterior and posterior. The border between them is the frontal plane, drawn through the root of the lung.

In textbooks on surgery, you can find the division of the mediastinum into right and left. At the same time, it is emphasized that, mainly, venous vessels are adjacent to the right mediastinal pleura, and arterial vessels to the left.

Recently, in the anatomical and clinical literature, the description of the organs of the thoracic cavity in connection with the upper and lower mediastinum is most often found; last, in. in turn, it is subdivided into anterior, middle and posterior. This division is in accordance with the international anatomical nomenclature of the last revision and is the basis for the presentation of the material in this methodological manual.

UPPER SEDOSTENIE (mediastinum superior) - the space located between the two leaves of the mediastinal pleura and bounded from above by the upper aperture of the chest, from below by the plane drawn between the angle of the sternum and the lower edge of the fourth thoracic vertebra.

The key structure of the upper "mediastinum is the aortic arch (arcus aonae). It begins at the level of the second right sternocostal articulation, rises up, approximately 1 cm, bends arcuately to the left side and descends to the level of the fourth thoracic vertebra, where it continues into the descending part aorta Three large vessels begin from the convex side of the aortic arch (Fig. 1, 2).

1. Brachiocephalic trunk (truncus brachiocephalicus) - departs at the level of the upper edge of the cartilage of the second rib and rises to the right sternoclavicular joint, where it is divided into the right common carotid and subclavian arteries.

2. The left common carotid artery (a.carotis communis sinistra) - originates to the left of the brachiocephalic trunk, goes to the left sternoclavicular joint and then continues to the neck.

3. The left subclavian artery (a.subclavia sinistra) - from the place of its origin through the upper aperture of the chest of the cage goes to the neck.

The following structures are located in front and to the right of the aortic arch:

Thymus gland (tymus), which consists of two lobes and is separated from the handle of the sternum by the retrosternal fascia. The gland reaches its maximum size in children, and then undergoes involution. In some cases, the upper border of the thymus can pass on the neck, the lower one - in the anterior mediastinum;

Brachiocephalic veins (vv. Brachiocephalicae) - lie behind the thymus gland. These vessels form in the lower part of the neck as a result of the fusion of the internal jugular and subclavian veins. The left brachiocephalic vein is three times as long as the right and crosses the superior mediastinum from top to bottom, from left to right. At the right edge of the sternum, at the level of the cartilage of the first rib, the brachiocephalic veins merge, resulting in the formation of the superior vena cava;

Superior vena cava (v. Cava superior) - descends along the right edge of the sternum to the second intercostal space, where it enters the pericardial cavity;

The right phrenic nerve (n. Phrenicus dexter) - enters the upper mediastinum between the right subclavian vein and the artery, descends along the lateral surface of the brachiocephalic and superior vena cava, and then lies in front of the lung root;

Brachiocephalic lymph nodes (nodi lymphatici brachiocephalici) - located in front of the veins of the same name, collect lymph from the thymus and thyroid glands, pericardium.

In front and to the left of the aortic arch are located:

The left superior intercostal vein (v. Intercostalis superior sinistra), collect blood from the upper three intercostal spaces and flow into the left brachiocephalic vein;

The left phrenic nerve (n. Phrenicus sinister) - enters the upper mediastinum in the interval between the left common carotid and subclavian arteries, crosses the left brachiocephalic vein behind, and then lies in front of the lung root;

The left vagus nerve (n.vagus sinister) - adjacent to the aortic arch and intersects with the phrenic nerve, located behind it.

Behind the aortic arch are located: - the trachea (trachea) - runs in a vertical direction, deviating slightly to the right of the midline. At the level of the fourth thoracic vertebra, the trachea divides into two main bronchi;

The esophagus (oesophageus) is in direct contact with the right mediastinal pleura, located behind the trachea and cnepere from the vertebral bodies, from which it is separated by the prevertebral adhesives and the intrathoracic fascia;

The right vagus nerve (n. Vagus dexter) - enters the upper mediastinum in front of the subclavian artery, at the lower edge of which the right recurrent laryngeal nerve originates from the i-th nerve. Then the n.vagus behind the brachio-leg vein approaches the lateral wall of the trachea, along which it directs to the root of the lung;

The left recurrent laryngeal nerve (item laryngeus recarrens sinister) - starts from the vagus nerve, first goes around the aortic arch from below, and then rises to the neck in the groove between the trachea and esophagus. Irritation of the laryngeal nerve with an aneurysm of the aortic arch or with syphilitic damage to its wall explains the presence of hoarseness in such patients and a long-lasting dry cough. Similar symptoms can also occur in lung cancer due to nerve irritation by enlarged lymph nodes.

The thoracic duct (ductus thoracius) - passes to the left of the esophagus and in the neck area flows into the left venous angle (the junction of the internal jugular and subclavian veins);

Paratracheal lymph nodes (nodi lymphatici paratracheales) - located around the trachea and collect lymph from the upper and lower tracheobronchial lymph nodes.

FOREQUARTERS (mediastinum anterior) - located anterior to the pericardium and bounded from above by a plane, connecting the angle of the sternum with the lower edge of the body of the fourth thoracic vertebra, from below by the diaphragm, in front by the sternum. In addition to loose fiber, it contains:

Periapical lymph nodes (nodi lymphatici parasternales) - located along the a. thoracica interna and collecting lymph from the mammary gland (medial lower quadrant), the upper third of the anterolateral abdominal wall, deep structures of the anterior chest wall and the upper surface of the liver;

-
upper diaphragmatic lymph nodes (nodi lymphatici superiores) - located at the base of the xiphoid process and collect lymph from the upper surface of the liver and the anterior part of the diaphragm.

FROM
MEDIUM MEDIUM (mediastinum medium) - includes the pericardium, right and left phrenic nerves, pericardial diaphragmatic arteries and veins.

The pericardium (pericardium) - consists of two leaves: the outer - fibrous (pericardium fibrosum) and the inner - serous (pericardium serosum). In turn, the serous pericardium is divided into two plates: the parietal, lining the fibrous pericardium from the inside, and the visceral, covering the vessels and heart (epicardium). The free space between the two plates of the pericardium serosum is called the pericardial cavity and is normally filled with a small amount of serous fluid.

The structure of the pericardium contains the following structures.

Heart (cor), which is projected onto the anterior surface of the chest between four points, located: the first - at the level of the cartilage of the right third rib, 1 - 1.5 centimeters from the edge of the sternum; the second - at the level of the cartilage of the left third rib, 2 - 2.5 centimeters from the edge of the sternum; the third - at the level of the right sixth sternocostal joint and the fourth - in the fifth intercostal space at a distance of 1 - 1.5 centimeters medially from the left midclavicular line.

The ascending part of the aorta (pars ascendens aortae) - starts from the left ventricle at the level of the cartilage of the third rib to the left of the sternum, rises up to the cartilage of the second rib, where, after leaving the pericardial cavity, it continues into the aortic arch (Fig. 3).

The lower segment of the superior vena cava, which, after entering the pericardium at the level of the 2nd intercostal space, ends in the right atrium.

The pulmonary trunk (truncus pulmonalis) - starts from the right ventricle and goes from right to left, front to back. In this case, the trunk is first ventrally, and then somewhat to the left of the ascending part of the aorta. Outside the pericardium, down from the aortic arch, there is a bifurcation of the pulmonary trunk (bifurcatio trunci pulmonalis). The pulmonary arteries starting in this place are directed to the gate of the lung. In this case, the left pulmonary artery passes in front of the descending part of the aorta, the right one - behind the superior vena cava and the ascending part of the aorta. The bifurcation of the pulmonary trunk is connected to the lower surface of the aortic arch using the arterial ligament, which in the fetus is a functioning vessel - the arterial (botal) duct.

Pulmonary veins (vv. Pulmonales) - enter the pericardial cavity shortly after leaving the gate of the lung and end in the left atrium. In this case, two right pulmonary veins run posterior to the superior vena cava, the two left - the ventrally descending part of the aorta.

The phrenic nerves in the middle mediastinum pass respectively between the right and left mediostinal pleura on one side and the pericardium on the other. The nerves accompany the pericardial diaphragmatic vessels. Arteries are branches of the internal thoracic arteries, veins are tributaries of w. ihoracicae, internae. In accordance with the international anatomical nomenclature, two sinuses are distinguished in the pericardial cavity:

Transverse (sinus transversus), limited in front by the aorta and pulmonary trunk, behind - by the left atrium, right pulmonary artery and superior vena cava (Fig. 4);

Oblique (sinus obliquus), bounded in front by the left atrium, behind by the parietal plate of the serous pericardium, above and on the left - by the left pulmonary veins, below and on the right - by the inferior vena cava (Fig. 5).

The clinical literature describes the third pericardial sinus, located at the transition of its anterior wall to the lower one.

Posterior MEDIUM (mediastinum posierius) - bounded behind by the bodies of the fifth to twelfth thoracic vertebrae, in front by the pericardium, laterally by the mediastinal pleura, below by the diaphragm, above by the plane connecting the angle of the sternum with the lower edge of the fourth thoracic vertebra. The key structure of the posterior mediastinum is the descending part of the aorta (pars desdendens aortae), which first lies on the left side of the vertebral bodies, and then shifts to the midline (Fig. 6). The following vessels depart from the descending part of the aorta:

Pericardial branches (rr. Pericardiaci) - supply blood to the back of the pericardium;

Bronchial arteries (aa. Bronchioles) - supply blood to the bronchial wall and lung tissue;

Esophageal arteries (aa.oesophageales) - supply blood to the wall of the thoracic esophagus;

Mediastinal branches (rr. Mediastinales) - supply blood to the lymph nodes and connective tissue of the mediastinum;

Posterior intercostal arteries (aa. Inrercosiales posreriores) - pass in the intercostal space, supply blood to the skin and muscles of the back, spinal cord, anastomoses with the anterior intercostal arteries;

The superior phrenic artery (a.phrenica superior) - forks on the upper surface of the diaphragm.

The following structures are located around the descending part of the aorta.

The right and left main bronchi (bronchus principalis dexter et sinister) - start from the bifurcation of the trachea at the level of the lower edge of the fourth thoracic vertebra. The left main bronchus departs at an angle of 45 ° in relation to the median plane and is directed behind the aortic arch to the hilum of the lung. The right main bronchus departs from the trachea at an angle of 25 ° in relation to the median plane. It is shorter than the left main bronchus and larger in diameter. This circumstance explains the significantly more frequent ingress of foreign bodies into the right bronchus in comparison with the left.

Esophagus (oesophageus) - lies first behind the left atrium and to the right of the descending part of the aorta. In the lower third of the mediastinum, the esophagus crosses the aorta in front, moves from it to the left side and is defined within the esophageal triangle, the boundaries of which are: in front of the pericardium, behind - the descending part of the aorta, below - the diaphragm. On the anterior and posterior surfaces of the esophagus there is the esophageal plexus (plexus oesophagealis), in the formation of which two vagus nerves are involved, as well as the branches of the thoracic nodes of the sympathetic trunk.

X-ray and endoscopic studies reveal a number of narrowing of the thoracic esophagus associated with the close interaction of its wall with neighboring organs. One of them corresponds to the aortic arch, the other - to the place of intersection of the esophagus by the left main bronchus. Expansion of the left atrium can also change the lumen of the esophagus when filled with a radiopaque contrast agent.

Unpaired vein (v. Azygos) - begins in the abdominal cavity, passes in the posterior mediastinum to the right of the vertebral bodies to the Th4 level, bends around the right main bronchus and flows into the superior vena cava outside the pericardial cavity. Its tributaries are all the posterior intercostal veins of the right side, as well as the bronchial, esophageal and mediastinal veins.

Semi-unpaired vein (v. Hemiazygos) - begins in the retroperitoneal space. In the posterior mediastinum, it passes behind the descending part of the aorta, at the level of the 7-8th thoracic vertebra it deviates to the right side and flows into the azygos vein. The tributaries of the semi-unpaired veins are the five lower (left) intercostal veins, esophageal, mediastinal, as well as the accessory semi-unpaired veins.

Additional semi-unpaired vein (V hemiazygos accessoria) - descends from the left side of the spinal column. The first 5-6 posterior (left) intercostal veins flow into it.

Thoracic duct (ductus thoracicus) - begins in the retroperitoneal space. In the posterior mediastinum, it passes between the azygos vein and the descending part of the aorta to the level of the sixth - fourth thoracic vertebra, where it deviates to the left, crosses the esophagus behind and continues into the upper mediastinum.

Operations on the mediastinal organs are performed according to the following indications:

1. Tumors of the thymus, thyroid and parathyroid glands, as well as tumors of a neurogenic nature.

Thymus tumors are most often located in front of the aortic arch and base of the heart. Very early invasion of these tumors into the wall of the superior vena cava, pleura and pericardium is observed. Compression of the left brachiocephalic and superior vena cava by thymoma ranks second in frequency after obstruction of these vessels by metastases in lung cancer.

With retrosternal goiter, the glandular tissue of the thyroid gland is most often located in an interval bounded from below by the right main bronchus, laterally by the mediastinal pleura, in front by the superior vena cava, medially by the right vagus nerve, trachea and the ascending part of the aorta.

Tumors of a neurogenic nature are the most common primary tumors of the mediastinum. Almost all of them are associated with the posterior mediastinum and are formed from the sympathetic trunk or intercostal nerves. In some cases, these tumors appear on the neck and then descend into the upper mediastinum. Due to the fact that tumors form near the intervertebral foramen, they can enter the spinal canal, causing compression of the spinal cord.

As an operative access when removing a mediastinal tumor, the following are used:

Lower cervical incision;

Median sternotomy;

Intercostal torocotomy.

2. Mediastinitis. They are usually formed as a result of the spread of infection from the cellular spaces of the neck or with perforation of the esophagus.

The opening and drainage of the abscesses of the upper mediastinum is carried out through an arcuate skin incision on the neck above the handle of the sternum (suprasternal mediastinotomy) by creating a canal behind the sternum. An incision can be made along the anterior edge of the sternocleidomastoid muscle, followed by opening the sheath of the neurovascular bundle or peri-oesophageal cellular tissue.

Drainage of the anterior mediastinum is carried out through an incision along the midline of the anterolateral abdominal wall. The opening of the abscess is carried out after dissecting the diaphragm, without violating the integrity of the peritoneum.

Opening of the abscesses of the posterior mediastinum is carried out from the side of the abdominal cavity (transabdominal mediastinotomy) or after performing a lateral torocotomy in the VII left intercostal space (transpleural mediastinotomy).

3. Pericarditis. They are characterized by inflammation of the visceral and parietal plates of the serous pericardium, resulting from a bacterial or viral infection, rheumatism or uremia. Pericarditis can lead to cardiac tamponade. In order to remove fluid and prevent tamponade, pericardial puncture is used (Larrey's method).

For a patient in a semi-sitting position, a long needle is injected into the angle between the base of the xiphoid process and the cartilage of the UP rib. Moreover, the needle is oriented perpendicularly to the surface of the anterolateral wall of the abdomen.After passing the needle to a depth of 1.5 cm, it is lowered and at an angle of 45 ° to the body surface is advanced up parallel to the posterior surface of the sternum until it penetrates into the antero-inferior pericardial sinus.

4. Wounds to the heart. Wound suturing is performed with nodular (linear wound) or U-shaped (lacerated wound) silk sutures, bypassing the endocardium and coronary vessels. The edges of the pericardium are connected by rare sutures, the pleural cavity is drained.

5. In addition to the listed cases, operations on the mediastinal organs are performed:

To stop bleeding caused by trauma or to correct vascular defects (stenosis, aneurysm);

With a tumor, trauma or congenital malformations of the esophagus;

For congenital and acquired heart defects, as well as for acute and chronic coronary insufficiency.

- a group of morphologically heterogeneous neoplasms located in the mediastinal space of the chest cavity. The clinical picture consists of symptoms of compression or germination of the mediastinal tumor into neighboring organs (pain, superior vena cava syndrome, cough, shortness of breath, dysphagia) and general manifestations (weakness, fever, sweating, weight loss). Diagnosis of mediastinal tumors includes X-ray, tomographic, endoscopic examination, transthoracic puncture or aspiration biopsy. Treatment of mediastinal tumors - operative; in case of malignant neoplasms, it is supplemented with radiation and chemotherapy.

General information

Tumors and cysts of the mediastinum make up 3-7% in the structure of all tumor processes. Of these, in 60-80% of cases, benign tumors of the mediastinum are detected, and in 20-40% - malignant (mediastinal cancer). Mediastinal tumors occur with the same frequency in men and women, mainly at the age of 20-40 years, that is, in the most socially active part of the population.

Tumors of mediastinal localization are characterized by morphological diversity, the likelihood of primary malignancy or malignancy, the potential threat of invasion or compression of vital organs of the mediastinum (respiratory tract, great vessels and nerve trunks, esophagus), and the technical difficulties of surgical removal. All this makes mediastinal tumors one of the urgent and most difficult problems of modern thoracic surgery and pulmonology.

Mediastinal anatomy

The anatomical space of the mediastinum in front is limited by the sternum, retrosternal fascia and costal cartilages; behind - the surface of the thoracic spine, prevertebral fascia and rib necks; on the sides - by the leaves of the mediastinal pleura, from below - by the diaphragm, and from above - by a conditional plane passing along the upper edge of the sternum handle.

The thymus gland, the upper sections of the superior vena cava, the aortic arch and its branches, the brachiocephalic trunk, the carotid and subclavian arteries, the thoracic lymphatic duct, sympathetic nerves and their plexuses, branches of the vagus nerve, fascial and cellular formations, lymph nodes, the esophagus are located within the mediastinum. , pericardium, tracheal bifurcation, pulmonary arteries and veins, etc. In the mediastinum, there are 3 floors (upper, middle, lower) and 3 sections (front, middle, back). The localization of neoplasms emanating from the structures located there corresponds to the floors and departments of the mediastinum.

Classification

All tumors of the mediastinum are divided into primary (initially arising in the mediastinal space) and secondary (metastases of neoplasms located outside the mediastinum).

Primary tumors of the mediastinum are formed from different tissues. In accordance with the genesis of tumors of the mediastinum, there are:

• neurogenic neoplasms (neuromas, neurofibromas, ganglioneuromas, malignant neuromas, paragangliomas, etc.)
• mesenchymal neoplasms (lipomas, fibromas, leiomyomas, hemangiomas, lymphangiomas, liposarcomas, fibrosarcomas, leiomyosarcomas, angiosarcomas)
• lymphoid neoplasms (lymphogranulomatosis, reticulosarcoma, lymphosarcoma)
• dysembryogenetic neoplasms (teratomas, intrathoracic goiter, seminoma, chorionepithelioma)
• tumors of the thymus gland (benign and malignant thymomas).

Also in the mediastinum there are so-called pseudotumors (enlarged conglomerates of lymph nodes in tuberculosis and Beck's sarcoidosis, aneurysms of large vessels, etc.) and true cysts (coelomic cysts of the pericardium, enterogenous and bronchogenic cysts, echinococcal cysts).

In the upper mediastinum, thymomas, lymphomas and retrosternal goiter are most often found; in the anterior mediastinum - mesenchymal tumors, thymomas, lymphomas, teratomas; in the middle mediastinum - bronchogenic and pericardial cysts, lymphomas; in the posterior mediastinum - enterogenic cysts and neurogenic tumors.

Symptoms of mediastinal tumors

In the clinical course of mediastinal tumors, an asymptomatic period and a period of severe symptoms are distinguished. The duration of the asymptomatic course is determined by the location and size of mediastinal tumors, their nature (malignant, benign), growth rate, and relationships with other organs. Asymptomatic mediastinal tumors are usually found during prophylactic fluorography.

General symptoms of mediastinal tumors include weakness, fever, arrhythmias, brady - and tachycardia, weight loss, arthralgia, pleurisy. These manifestations are more characteristic of malignant tumors of the mediastinum.

Pain syndrome

The earliest manifestations of both benign and malignant tumors of the mediastinum are chest pains caused by compression or invasion of the neoplasm into the nerve plexuses or nerve trunks. The pains are usually moderately intense, can radiate to the neck, shoulder girdle, interscapular region.

Tumors of the mediastinum with left-sided localization can simulate pain resembling angina pectoris. When a tumor compresses or invades the mediastinum of the borderline sympathetic trunk, Horner's symptom often develops, including miosis, ptosis of the upper eyelid, enophthalmos, anhidrosis and hyperemia of the affected side of the face. With bone pain, you should think about the presence of metastases.

Compression Syndrome

Compression of the venous trunks is primarily manifested by the so-called superior vena cava syndrome (SVCS), in which the outflow of venous blood from the head and upper half of the body is impaired. SVC syndrome is characterized by heaviness and noise in the head, headache, chest pain, shortness of breath, cyanosis and swelling of the face and chest, swelling of the neck veins, and increased central venous pressure. In case of compression of the trachea and bronchi, cough, shortness of breath, stridor breathing occur; recurrent laryngeal nerve - dysphonia; esophagus - dysphagia.

Specific manifestations

Some tumors of the mediastinum develop specific symptoms. So, with malignant lymphomas, night sweats and skin itching are noted. Fibrosarcomas of the mediastinum can be accompanied by a spontaneous decrease in blood glucose levels (hypoglycemia). Ganglioneuromas and mediastinal neuroblastomas can produce norepinephrine and adrenaline, which leads to bouts of arterial hypertension. They sometimes secrete a vasointestinal polypeptide that causes diarrhea. With intrathoracic thyrotoxic goiter, symptoms of thyrotoxicosis develop. Myasthenia gravis is detected in 50% of patients with thymoma.

Diagnostics

The variety of clinical manifestations does not always allow pulmonologists and thoracic surgeons to diagnose mediastinal tumors based on anamnesis and objective research. Therefore, instrumental methods play a leading role in the detection of mediastinal tumors.

• X-ray diagnostics. Comprehensive X-ray examination in most cases allows you to clearly determine the localization, shape and size of the mediastinal tumor and the extent of the process. Mandatory examinations for suspected mediastinal tumor are chest fluoroscopy, polypositional radiography, and esophageal radiography. X-ray data are clarified using bone marrow puncture with myelogram examination.
• Surgical biopsy. Preferred methods of obtaining material for morphological examination are mediastinoscopy and diagnostic thoracoscopy, allowing for biopsy under visual control. In some cases, it becomes necessary to perform a parasternal thoracotomy (mediastinotomy) for revision and biopsy of the mediastinum. In the presence of enlarged lymph nodes in the supraclavicular region, a pre-scalded biopsy is performed.

Mediastinal tumor treatment

In order to prevent malignancy and the development of compression syndrome, all mediastinal tumors should be removed as early as possible. For radical removal of mediastinal tumors, thoracoscopic or open methods are used. With the retrosternal and bilateral location of the tumor, longitudinal sternotomy is mainly used as an operative access. With unilateral localization of the mediastinal tumor, anterolateral or lateral thoracotomy is used.

Transthoracic ultrasound aspiration of the mediastinal neoplasm can be performed in patients with a severe general somatic background. In a malignant process in the mediastinum, a radical extended removal of the tumor or palliative removal of the tumor is performed in order to decompress the mediastinal organs.

The question of the use of radiation and chemotherapy for malignant tumors of the mediastinum is decided based on the nature, prevalence and morphological features of the tumor process. Radiation and chemotherapy treatments are used both independently and in combination with surgical treatment.

Front anterior mediastinal wall is the sternum, covered by the intrathoracic fascia, the posterior is the anterior wall of the pericardium. On the sides, it is limited by the sagittal branches of the intrathoracic fascia and the anterior transitional folds of the pleura. In this area, the transitional folds of the pleura lie very close to each other, often connected by a ligament.

Anterior mediastinum, extending from above from the horizontal plane at the level of the tracheal bifurcation, and from below to the diaphragm, is also called the retrosternal (retrosternal) cellular space.

The contents of the space are fiber, internal thoracic vessels and anterior lymph nodes of the mediastinum. A.et v. thoracicae intemae up to level II of the costal cartilages are located between the pleura and the intrathoracic fascia, the latter is pierced below and lie in front of it, and below the III ribs lie on the sides of the sternum (up to 2 cm from the edges) between the internal intercostal muscles and the transverse muscle of the chest.

At the same level front the transitional folds of the pleura begin to diverge to the sides (more to the left), forming the lower interpleural triangle.

On the lower (diaphragmatic) the wall of the anterior mediastinum you can see two sternocostal triangles between the pars stemalis and pars costalis of the diaphragm, where the intrathoracic and intra-abdominal fascia are adjacent to each other.

From the fibrous pericardium to the intrathoracic fascia in the sagittal direction, the upper and lower sterno-pericardial ligaments, ligamenta sternopericardiaca.

IN anterior mediastinal tissue pre-pericardial lymph nodes are located. They are connected through the intercostal space with the lymphatic vessels of the mammary gland, as a result of which they are quite often affected by metastases in breast cancer.

Mediastinal tumor is a relatively rare pathology. According to statistics, formations in this area are found in no more than 6-7% of all human tumors. Most of them are benign, only a fifth are initially malignant.

Among patients with neoplasms of the mediastinum, approximately the same number of men and women, and the predominant age of the sick is 20-40 years, that is, the most active and young part of the population suffers.

From the morphological point of view, tumors of the mediastinal region are extremely heterogeneous, but almost all of them, even benign in nature, are potentially dangerous due to possible compression of the surrounding organs. In addition, the localization feature makes them difficult to remove, and therefore they seem to be one of the most difficult problems of thoracic surgery.

Most people who are far from medicine have a very vague idea of \u200b\u200bwhat the mediastinum is and what organs are there. In addition to the heart, the structures of the respiratory system, large vascular trunks and nerves, the lymph apparatus of the chest, which can give rise to all kinds of formations, are concentrated in this area.

The mediastinum (mediastinum) is the space, the anterior part of which is formed by the sternum, the anterior portions of the ribs, covered from the inside by the posterior-sternal fascia. The posterior mediastinal wall is the anterior surface of the spinal column, the prevertebral fascia, and the posterior ribs. The lateral walls are represented by pleural sheets, and below the mediastinal space is closed by a diaphragm. The upper part does not have a clear anatomical border, it is an imaginary plane going through the upper end of the sternum.

Within the mediastinum are the thymus, the upper segment of the superior vena cava, the aortic arch and arterial vascular lines originating from it, the thoracic lymphatic duct, nerve fibers, fiber, the esophagus runs behind, in the middle zone the heart is located in the pericardial bursa, the zone of division of the trachea into bronchi, pulmonary vessels.

In the mediastinum, the upper, middle and lower floors are distinguished, as well as the front, middle and back parts. To analyze the extent of tumor prevalence, mediastinum is conventionally divided into upper and lower halves, the border between which is the upper part of the pericardium.

In the posterior mediastinum, the growth of neoplasms from lymphoid tissue (), neurogenic tumors, and metastatic cancers of other organs is characteristic. In the anterior mediastinal region, lymphoma and teratoid tumors, mesenchymomas from connective tissue components are formed, while the risk of malignant neoplasia of the anterior mediastinum is higher than in other parts. In the middle mediastinum, lymphomas, cystic cavities of bronchogenic and dysembryogenetic genesis, and other cancers are formed.

Tumors of the upper mediastinum are thymomas, lymphomas, and intrathoracic goiter as well. Thymomas, bronchogenic cysts are found in the middle floor, and pericardial cysts and fatty neoplasms are found in the lower mediastinal region.

Classification of neoplasms of the mediastinum

Mediastinum tissues are extremely diverse, therefore, tumors in this area are united only by a common location, otherwise they are diverse and have different sources of development.

Tumors of the mediastinal organs are primary, that is, initially growing from the tissues of this area of \u200b\u200bthe body, and also secondary - metastatic nodes of cancers of other localization.

Primary mediastinal neoplasias are distinguished by histogenesis, that is, the tissue that became the ancestor of pathology:

• Neurogenic -, ganglioneuroma - grow from peripheral nerves and nerve ganglia;
• Mesenchymal -, fibroma, etc .;
• Lymphoproliferative - Hodgkin's disease, lymphoma, lymphosarcoma;
• Dysontogenetic (formed in violation of embryonic development) - teratomas, chorionepithelioma;
• - neoplasia of the thymus gland.

Mediastinal neoplasms are mature and immature, while mediastinal cancer is not quite the correct wording, given the sources of its origin. Cancer is called epithelial neoplasia, and in the mediastinum formations of connective tissue genesis and teratoma are found. Cancer in the mediastinum is possible, but it will be of a secondary nature, that is, it will arise as a result of metastasis of carcinoma of another organ.

Thymomas - these are tumors of the thymus gland that affect people 30-40 years old. They account for about a fifth of all mediastinal tumors. Distinguish between malignant thymoma with a high degree of invasion (germination) of the surrounding structures, and benign. Both varieties are diagnosed with approximately equal frequency.

Dysembryonic neoplasia - also not uncommon in mediastinum, up to a third of all teratomas are malignant. They are formed from embryonic cells that have remained here from the moment of intrauterine development, and contain components of epidermal and connective tissue origin. Usually, the pathology is detected in adolescents. Immature teratomas grow actively, metastasize to the lungs and nearby lymph nodes.

Favorite tumor localization neurogenic origin - nerves of the posterior mediastinum. The vagus and intercostal nerves, spinal membranes, sympathetic plexus can become carriers. They usually grow without causing any concern, but the spread of neoplasia into the canal of the spinal cord can provoke compression of the nerve tissue and neurological symptoms.

Tumors of mesenchymal origin - the widest group of neoplasms, diverse in structure and source. They can develop in all parts of the mediastinum, but more often in the anterior part. Lipomas are benign tumors from adipose tissue, usually unilateral, can spread up or down the mediastinum, penetrate from the anterior to the posterior region.

Lipomas have a soft consistency, due to which the symptoms of compression of adjacent tissues do not occur, and pathology is discovered by chance during examination of the chest organs. A malignant analogue - liposarcoma - is rarely diagnosed in the mediastinum.

Fibromas are formed from fibrous connective tissue, grow asymptomatically for a long time, and the clinic is called upon reaching a large size. They can be multiple, of different shapes and sizes, and have a connective tissue capsule. Malignant fibrosarcoma grows rapidly and causes pleural effusion.

Hemangiomas - tumors from the vessels, are quite rare in mediastinum, but usually affect its anterior section. Neoplasms from lymphatic vessels - lymphangiomas, hygromas - usually occur in children, form nodes, and can grow into the neck, causing displacement of other organs. Uncomplicated forms are asymptomatic.

Mediastinal cyst - This is a tumor-like process, which is a rounded cavity. The cyst is congenital and acquired. Congenital cysts are considered a consequence of impaired embryonic development, and their source can be the tissue of the bronchus, intestines, pericardium, etc. - bronchogenic, enterogenic cystic formations, teratomas. Secondary cysts form from the lymphatic system and tissues that are normally present here.

Symptoms of mediastinal tumors

For a long time, the tumor of the mediastinum is able to grow latently, and the signs of the disease appear later, when the surrounding tissues are compressed, germinated, and metastasis begins. In such cases, pathology is detected during examination of the chest organs for other reasons.

The location, volume and degree of tumor differentiation determine the duration of the asymptomatic period. Malignant neoplasms grow faster, so the clinic appears earlier.

The main features of mediastinal tumors include:

1. Symptoms of squeezing or invasion of the neoplasia into the surrounding structures;
2. General changes;
3. Specific changes.

The main manifestation of pathology is considered pain syndrome, which is associated with the pressure of the neoplasm or its invasion into the nerve fibers. This symptom is characteristic not only for immature, but also for completely benign tumor processes. The pains bother on the side of the growth of the pathology, not too intense, pulling, can be given to the shoulder, neck, interscapular region. With left-sided pain, it can be very similar to that of angina.

An increase in bone tenderness is considered an unfavorable symptom, which most likely indicates possible metastasis. For the same reason, pathological fractures are possible.

Typical symptoms appear when nerve fibers are involved in tumor growth:

• Ptosis of the eyelid (ptosis), retraction of the eye and dilated pupil from the side of neoplasia, sweating disorder, fluctuations in skin temperature indicate the involvement of the sympathetic plexus;
• Hoarseness (laryngeal nerve is affected);
• An increase in the level of the diaphragm during the sprouting of phrenic nerves;
• Sensory disorders, paresis and paralysis during compression of the spinal cord and its roots.

One of the symptoms of compression syndrome is the narrowing of the venous lines by a tumor, more often the superior vena cava, which is accompanied by difficulty in venous outflow from the tissues of the upper body and head. Patients in this case complain of noise and a feeling of heaviness in the head, increasing when bending, soreness in the chest, shortness of breath, edema and cyanotic skin of the face, expansion and overflow of blood in the cervical veins.

The pressure of the neoplasm on the airways provokes coughing and shortness of breath, and compression of the esophagus is accompanied by dysphagia, when it is difficult for the patient to eat.

Common signs of tumor growth weakness, decreased performance, fever, sweating, weight loss, which indicate the malignancy of the pathology. The progressive increase in the tumor causes intoxication with the products of its metabolism, which is associated with joint pain, edema syndrome, tachycardia, arrhythmias.

Specific symptoms characteristic of certain types of neoplasms of the mediastinum. For example, lymphosarcomas cause itching of the skin, sweating, and fibrosarcomas occur with episodes of hypoglycemia. Intrathoracic goiter with increased hormone levels is accompanied by signs of thyrotoxicosis.

Symptoms of mediastinal cysts associated with the pressure that it exerts on neighboring organs, so the manifestations will depend on the size of the cavity. In most cases, cysts are asymptomatic and do not cause any discomfort in the patient.

With pressure from a large cystic cavity on the mediastinal contents, shortness of breath, cough, swallowing disorders, a feeling of heaviness and pain in the chest may occur.

Dermoid cysts, which are the result of intrauterine growth disorders, often give symptoms of cardiac and vascular disorders: shortness of breath, cough, heart pain, increased heart rate. When the cyst is opened, a cough appears in the lumen of the bronchus with the release of sputum, in which hair and fat are distinguishable.

Dangerous complications of cysts are considered to be their rupture with an increase in pneumothorax, hydrothorax, the formation of fistulas in the chest cavity. Bronchogenic cysts can suppurate and lead to hemoptysis when opened into the lumen of the bronchus.

Thoracic surgeons and pulmonologists are more likely to encounter neoplasms of the mediastinal region. Given the variety of symptoms, the diagnosis of mediastinal pathology presents significant difficulties. Radiography, MRI, CT, and endoscopic procedures (broncho- and mediastinoscopy) are used to confirm the diagnosis. A biopsy allows you to finally verify the diagnosis.

Video: lecture on the diagnosis of tumors and cysts of the mediastinum

Treatment

The only correct way to treat mediastinal tumors is surgery.The earlier it is carried out, the better the prognosis for the patient. In benign tumors, open intervention is performed with complete excision of the neoplasia growth focus. In the case of malignancy of the process, the most radical removal is shown, and depending on the sensitivity to other types of anticancer treatment, chemotherapy and radiation therapy is prescribed, both independently and in combination with an operation.

When planning a surgical procedure, it is extremely important to choose the right approach that gives the surgeon the best view and space for manipulation. The likelihood of recurrence or progression of the pathology depends on the radicality of the removal.

Radical removal of neoplasms in the mediastinal region is performed by thoracoscopy or thoracotomy - anterolateral or lateral. If the pathology is located retrosternal or on both sides of the chest, a longitudinal sternotomy with a dissection of the sternum is considered preferable.

Videothoracoscopy - a relatively new method of treating a mediastinal tumor, in which the intervention is accompanied by minimal surgical trauma, but at the same time, the surgeon has the opportunity to examine the affected area in detail and remove the altered tissues. Videothoracoscopy allows achieving high treatment results even in patients with serious background pathology and a small functional reserve for further recovery.

In severe concomitant diseases that complicate the operation and anesthesia, palliative treatment is carried out in the form of removal of the tumor by means of ultrasound with a transthoracic access or partial excision of tumor tissues for decompression of the mediastinal formations.

Video: lecture on mediastinal tumor surgery

Forecast with mediastinal tumors is ambiguous and depends on the type and degree of tumor differentiation. With thymomas, cysts, retrosternal goiter, mature connective tissue neoplasias, it is favorable, provided they are promptly removed. Malignant tumors not only squeeze and germinate organs, disrupting their function, but also actively metastasize, which leads to an increase in cancer intoxication, the development of serious complications and the death of the patient.

The author selectively answers the readers' adequate questions within the framework of his competence and only within the OnkoLib.ru resource. At the moment, face-to-face consultations and assistance in organizing treatment are not provided.