Mediastinitis

MEDIASTINITIS (mediastinitis), inflammation of the connective tissue of the mediastinum. Depending on the location of the process in the anterior or posterior part of the mediastinum, anterior and posterior mediastinitis are distinguished. Mediastinitis occurs not often. Anterior mediastinitis is more frequently observed. Thus (according to Hare), out of 65 cases of mediastinitis (acute and chronic), in 50 cases there was anterior mediastinitis_}, in 12 cases - posterior, and in 3 cases - mediastinitis of both mediastinums. The presence of loose, lymphatic vessel-rich connective tissue in the mediastinum is an extremely favorable condition for the development and spread of inflammatory processes. Numerous lymphatic pathways pass through the mediastinum, carrying lymph from various areas of the body. Therefore, it is understandable that when inflammatory processes exist in one or another part of the body, infection can spread through the lymphatic pathways to the mediastinum. Moreover, the richness of the mediastinum in lymphatic pathways ensures rapid absorption of infectious agents and, consequently, the severe course of localized inflammatory processes in the mediastinum, which quickly lead to general septic infection of the body. Acute and chronic mediastinitis are distinguished. The greatest clinical significance belongs to acute infectious mediastinitis. Acute mediastinitis can develop due to various causes. 1) Primary - due to the action of direct trauma (gunshot and stab wounds, complicated fractures of the sternum and ribs), when infection penetrates the mediastinum by mechanical force or a foreign body (a lodged bullet, shrapnel fragment, piece of clothing, etc.). Sometimes mediastinitis can also develop after the action of blunt force. 2) Most often, mediastinitis develops secondarily. a) By direct spread of infection (per continuitatem) from organs of the mediastinum or its vicinity. This includes the spread of inflammatory processes to the mediastinum from the neck (inflammation of the loose connective tissue surrounding the large neck vessels, in front of and behind the larynx and trachea, especially behind the pharynx and esophagus). Phlegmons around the esophagus and respiratory tract can easily spread per continuitatem to the mediastinum. Perforation of the esophagus, especially when it contains foreign bodies, fairly often leads to the development of severe putrefactive mediastinitis (with the improvement and spread of esophagoscopy, cases of mediastinitis due to foreign bodies of the esophagus are encountered less frequently). The causes of mediastinitis development can also be diseases of the pleura and pericardial sac (rupture of empyema or pericardial exudate), as well as the transition of inflammatory processes from the spine, ribs, sternum, etc., and from purulent-fused lymph glands. b) Finally, mediastinitis can develop by the metastatic route: transfer of infection by the blood or lymphatic pathway in infectious diseases (especially in erysipelas and typhus, pneumonia, etc.) and in purulent inflammations (e.g., paronychia, phlegmon, abscess) in distant parts of the body. Acute mediastinitis can occur in the form of phlegmon or abscess. Phlegmons, accompanied by diffuse infiltration of loose connective tissue without a tendency to form pus, are especially dangerous (such phlegmons not infrequently spread to the mediastinum from the neck). Abscesses located in the anterior mediastinum can sometimes rupture outward or can be cured by a relatively simple operation. Abscesses and phlegmons of the posterior mediastinum are much more severe in course and difficult to access for treatment; they, although sometimes developing upward (toward the neck - jugulum, supraclavicular fossa), but more often occupy a deep position in the mediastinum, can descend downward, and, passing between the diaphragmatic pillars, in some cases reach the retroperitoneal space. Collections of pus in the posterior mediastinum can rupture into adjacent serous cavities and hollow organs. - Among the clinical manifestations of acute mediastinitis, severe pain behind the sternum, which often occurs in attacks and is often aggravated with each heartbeat, should be placed first. Pains also occur behind the spine. In the presence of anterior mediastinitis, the sternum may be sensitive to pressure and percussion. Usually, mediastinitis is accompanied by high temperature. Often, shaking chills and sweats are observed. Most patients die soon from general septic infection. If an abscess forms in the mediastinum, the prognosis becomes relatively more favorable. A diagnostic puncture made in the III or IV intercostal space directly at the edge of the sternum (in anterior mediastinitis) can reveal the presence of pus. With the development of a large abscess in the mediastinum, symptoms of compression of neighboring organs by exudate soon appear - heart, large vessels, nerves, respiratory tube, etc., as a result of which disturbances in cardiac activity and breathing, pains, etc., develop. In far-advanced cases of mediastinitis, edematous swelling may appear on the neck (above the jugulum, in the supraclavicular fossa), which is of great importance for the diagnosis of mediastinitis. If the cause of posterior mediastinitis, as is often the case, is perforation of the esophagus, e.g., by a foreign body, then due to the entry of air from the stomach, mediastinal emphysema develops, which can be detected by the appearance of subcutaneous emphysema on the neck (swelling, crepitus). With complications in the form of rupture of the abscess into any of the hollow organs, a complex picture of the disease develops with symptoms characteristic of diseases of these organs. The diagnosis of mediastinitis in the presence of characteristic pains, fever, and symptoms of compression of neighboring organs, along with the presence of diseases and injuries of the esophagus, respiratory tract, spine, etc., that can be etiological factors for the development of mediastinitis, does not present great difficulties. In cases where the picture of an abscess is clearly outlined, every doubt disappears. In initial and neglected cases (with rupture of pus into adjacent cavities), the diagnosis is difficult. It is often difficult to determine where the process is localized - in the anterior or posterior mediastinum. - The prognosis in any acute mediastinitis is extremely serious. It is especially unfavorable in phlegmonous mediastinitis without a tendency to form pus. Most such patients die from general septic infection. When an abscess ruptures - into the respiratory tract, death from suffocation may occur. Abscesses developing in the anterior mediastinis give a better prognosis, as they are less dangerous in their course and more accessible for surgical intervention, and also because in such cases spontaneous healing is possible by rupture of the abscess outward in the intercostal space, jugulum, or in some other distant area (by the spread of pus under the skin). Collections of pus in mediastinitis can rupture into the trachea, esophagus, pericardial sac, pleura. - Besides the serious significance that mediastinitis has in itself, great clinical significance can be attached to the callus-like scars, adhesions, and shrinkage of the tissues involved in the process, which affect the position and function of neighboring organs (pericardial sac, heart, pleura, lungs). Due to the direct connection of the pericardial sac with the mediastinal connective tissue, chronic inflammation of the pericardium (chronic adhesive pericarditis) can spread to the connective tissue of the mediastinum, leading to the development of mediastino-pericarditis. As a result of this chronic process, adhesions form between the heart and the pericardial sac; on the other hand, the proliferating scar tissue can spread to the mediastinal connective tissue, large vessels, esophagus, diaphragm, pleura. As a result of all this, the heart with the pericardial sac becomes attached to the anterior chest wall or is tightly surrounded by connective tissue masses. The proliferating connective tissue gradually densifies, acquires the character of callus-like membranes, in which the heart can be walled up (callus pericarditis). When these masses shrink, compression of the heart and difficulty in its work occur, especially diastole, and due to compression of the thin-walled atria and large veins, a significant obstacle is created for the inflow of venous blood to the heart. When the heart adheres to the anterior chest wall, cardiac disorders are eliminated by Brauer's operation (mobilization of the anterior chest wall by extensive resection of ribs in the precordial area); in cases where the heart is walled up in the surrounding callused scar tissue, surgical release of the heart from adhesions (cardiolysis endopericardiaca) is applied. The treatment of mediastinitis can only be surgical, and hope for success of the operation is possible only with timely diagnosis and accessibility of the focus of the disease for surgical intervention. Generally speaking, surgical treatment of mediastinitis is successful only in forms accompanied by the development of an abscess. - The methods of surgical intervention in mediastinitis vary depending on the case and the location of the process in the anterior or posterior mediastinums. Anterior mediastinitis is less dangerous, and surgical intervention here is relatively simple due to the greater accessibility of the anterior mediastinum compared to the posterior. The opening of the anterior mediastinum for emptying pus was performed even by Galen. Especially favorable are cases where there is an easily determinable abscess near the sternum or jugulum.

In such cases, a simple incision may be sufficient. For a retrosternal abscess, it is necessary to open the abscess, creating access to it by trepanation or by extensive resection of the sternum. In certain cases, the abscess can be opened through a parasternal incision, by resecting one or two costal cartilages near the sternum, and it should be previously confirmed by a trial puncture that pus is present. For posterior mediastinitis, different approaches must be taken depending on the case. Where mediastinitis is caused by an inflammatory process descending from the neck, or for deep suppuration localized in the posterior mediastinum and extending upward (to the supraclavicular fossa, jugulum, behind the esophagus), sometimes a wide incision from the side of the neck (cervical mediastinotomy-mediastinotomia collaris) is sufficient. In such cases, an incision is made as in esophagotomy, exposing the esophagus; the incision is extended to the jugulum to trace the esophagus as far downward as possible (to the superior aperture of the thoracic cavity). If the periesophageal phlegmon is located in the upper part of the mediastinum, access to the Dm can be achieved from the side of the neck through an incision above the clavicle, penetrating between both heads of the m. sterno-cleido-mastoidei, sometimes by separating this muscle transversely from the clavicle. For better subsequent drainage of pus after opening the mediastinum from the neck, the patient should be kept in the Trendelenburg position postoperatively. Opening the mediastinum from the neck can be successfully performed in cases where the accumulation of pus does not descend in the mediastinum below the Dni. The first case of successful treatment of mediastinitis by means of cervical mediastinotomy belongs to Razumovsky. When the abscess is deeply located in the posterior mediastinum, it is necessary to open the mediastinum from behind (posterior dorsal mediastinotomy). There are many methods of dorsal mediastinotomy, proposed by various surgeons for the purpose of exposing the thoracic part of the esophagus, bronchi, and opening purulent accumulations in the posterior mediastinum (Nasilov, Quenu and Hartmann, Bryant, Rehn, Enderlen, etc.). For opening a purulent mediastinitis from behind (perforation of the esophagus by a foreign body, during probing, etc.), it is recommended to open the mediastinum to the right of the spine and only under specific indications—to the left, while avoiding damage to the pleura. The best way to open abscesses of the posterior mediastinum is costotranversectomia. By a paravertebral incision, dividing the musculature on both sides, the transverse processes of several vertebrae are exposed, some of which are resected; the vertebral ends of several ribs are also resected. Other surgeons recommend resecting the ribs not at the spine itself, but laterally from it, corresponding to the angles of the ribs (Quenu, Hartmann), and from there penetrate into the mediastinum. For opening purulent accumulations in the posterior mediastinum, Potarca proposed the following method: an incision is made from the II to VI rib midway between the vertebral border of the scapula and the line of the spinous processes of the thoracic vertebrae. In addition to this incision, two more are made: transversely at the upper and lower ends of the vertical incision. The two resulting flaps, containing the skin and muscular layer, are separated and reflected—exposing the III-V ribs. Each of these ribs is freed from the periosteum and resected for a length of 3-5 cm. The resected segments should extend from the median line to the ends of the corresponding transverse processes. The intercostal arteries are ligated and cut between two ligatures, the remaining periosteum and muscular layer are spread aside. The pleura is exposed, which forms a fold when transitioning from the ribs to the mediastinum. The pleura can be separated and retracted to the side, after which some access to the mediastinum is obtained. Among chronic specific mediastinitides, tuberculous mediastinitis has clinical significance; tuberculosis of the mediastinum arises from the rupture of caseously degenerated lymph glands or from the spread of the tuberculous process to the mediastinum from the sternum, especially from the spine. Steindler, among his material covering 280 cases of spondylitis, found mediastinal abscesses in 25% of all cases. In the clinic of Eiselsberg, caries of the spine was accompanied by radiologically established cold abscesses in the posterior mediastinum in almost 2/3 of cases. Tuberculous lesions of the mediastinum, especially cold abscesses, can be treated by active surgical intervention. Puncture of mediastinal abscesses followed by injection of iodoform emulsion, although sometimes used, is rejected by most surgeons as an unsafe method. A more appropriate procedure is the evacuation of the abscess by resection of the sternum and costotransversectomy for posterior mediastinal abscesses. Such surgical intervention is especially indicated in cases of compression of surrounding organs by the abscess (compression of the spinal cord with paralysis, compression of the trachea, dysphagia, etc.).