Mediastinitis is an aseptic or microbial inflammatory process in the mediastinal fiber with an acute or chronic course. The development of acute mediastinitis is characterized by pain behind the sternum, fever, chills, tachycardia, severe endogenous intoxication. With chronic mediastinitis, symptoms of compression of the mediastinal organs (cough, shortness of breath, dysphagia) come to the fore. Diagnosis of mediastinitis is carried out taking into account the data of X-ray examination, CT, ultrasound, esophagoscopy, bronchoscopy, mediastinoscopy. Therapeutic tactics for mediastinitis is active, requires the elimination of the cause of inflammation and mediastinotomy with adequate drainage of the purulent focus.
ICD 10
J98.5 J85.3
Meaning
Mediastinitis is a life-threatening condition and in case of delayed diagnosis or inadequate treatment is accompanied by high mortality rates. Practice shows that only 15-20% of cases of mediastinitis are detected in vivo, which is associated with a rapidly progressive course of the disease and insufficiently pathognomonic manifestations against the background of a general severe infection.
Mediastinitis can be complicated by a significant number of pathological conditions of the lungs, pleura, trachea, neck, oral cavity, larynx, pharynx, esophagus, heart, etc. Taking into account the diversity of causes, mediastinitis is of clinical interest not only for pulmonology and thoracic surgery, but also for otolaryngology, gastroenterology, cardiology, dentistry.
Causes of mediastinitis
Primary mediastinites
Primary traumatic mediastinitis occurs due to exogenous infection. Most often this happens with open, including gunshot, injuries of the mediastinal organs. The second most common cause of primary mediastinitis is esophageal trauma during instrumental manipulations (esophageal augmentation, cardiodilatation, esophagoscopy, tracheal intubation, tracheostomy, gastric probing). Often esophageal injuries are caused by foreign bodies, spontaneous rupture of the esophagus, burns, perforation of the diverticulum, ulceration of tumors, etc.
Primary mediastinitis also includes postoperative inflammation of the mediastinal fiber caused by a violation of the tightness of esophageal-gastric anastomoses (after resection and plastic surgery of the esophagus, gastric resection), complications of cardiac surgery (mammarocoronary bypass surgery, coronary artery bypass grafting, mitral valve and aortic valve prosthetics).
Secondary mediastinites
Secondary mediastinitis is a complication of some purulent or destructive process and develops with the direct transition of inflammation to mediastinal tissue or metastasis of pathogens from established or unidentified infectious foci. Contact mediastinitis can develop against the background of neck wounds and phlegmon, purulent thyroiditis, pneumonia, lung and pleural wounds, lung abscess and gangrene, tuberculosis, pleural empyema, bronchiectatic disease, esophageal pleural fistulas, pericarditis, osteomyelitis of the sternum, ribs and thoracic spine.
The source of infection in metastatic mediastinitis may be upper and lower extremity phlegmons, frostbite, periostitis, osteomyelitis of the lower jaw, pharyngeal abscess in tonsillitis, phlegmonous mumps, sore throat, ulcerative colitis, dysentery, erysipelas, lymphadenitis, sepsis, and many others.
Pathological anatomy
Mediastinum is a space in the thoracic cavity centrally located in relation to the lungs. The mediastinum is bounded in front by the sternum, in the back by the vertebral column, on the sides by the mediastinal pleura, from below by the diaphragm; at the top, without clear boundaries, the mediastinum passes into the neck area. In the mediastinum, there are upper and lower floors with a conditional border in the region of the IV thoracic vertebra. In the upper mediastinum, the anterior and posterior sections are distinguished; in the lower – the anterior, middle and posterior sections.
In the anterior part of the upper mediastinum are the thymus gland, the aortic arch, the superior vena cava, and the pulmonary artery. The anterior part of the posterior mediastinum is occupied by the heart and pericardium; the middle part is bifurcation of the trachea, lymph nodes, trunk and branches of the pulmonary artery, the ascending part of the aorta. In the posterior mediastinum of the anterior and lower floors pass the esophagus, thoracic lymphatic duct, borderline sympathetic trunk, descending part of the aorta, inferior vena cava, unpaired and paired veins.
All floors and departments of the mediastinum are a single, topographically-anatomically connected space without clear boundaries, so purulent inflammation in mediastinitis can spread from one part of the mediastinum to another. To a certain extent, this is facilitated by the constant movement of the mediastinal organs: heart tremors, pulsation of blood vessels, displacement of the trachea during talking and coughing, peristalsis of the esophagus, etc.
Classification
In accordance with the etiopathogenetic mechanisms, primary (traumatic) mediastinitis in wounds of the mediastinal organs and secondary mediastinitis caused by contact and metastatic penetration of infection from other areas are distinguished. According to the clinical course, mediastinitis can be lightning–fast, acute and chronic; by the nature of inflammation – serous, purulent, anaerobic, putrefactive, gangrenous, tuberculous.
Chronic mediastinitis can be aseptic and microbial. Among aseptic mediastinitis, idiopathic, rheumatic, posthemorrhagic adiposclerotic, etc. are distinguished; among microbial – specific (tuberculous, syphilitic, mycotic) and nonspecific. Acute mediastinitis, as a rule, is infectious in nature.
Taking into account the tendency to spread, lymphadenitis with involvement of mediastinal fiber, abscesses and mediastinal phlegmons, which may be prone to restriction or progressive, are distinguished.
According to the topography and anatomical interest of mediastinal structures, mediastinites are divided into:
- anteropteric (above level III intercostal space)
- anteropteric (below level III intercostal space)
- spilled anterior (involving the upper and lower parts)
- posterior (above the level of the V thoracic vertebra)
- posterior (below the level of the V thoracic vertebra)
- posterior
- spilled posterior (involving the upper, middle and lower divisions)
- total (spreading to the anterior and posterior mediastinum).
Symptoms of mediastinitis
Acute mediastinitis usually develops suddenly, manifesting with chest pains, terrific chills, high fever (up to 39-40 ° C), profuse sweating, shortness of breath. If there is a purulent process of a different localization in the body, with the addition of mediastinitis, the general condition deteriorates sharply, the phenomena of purulent intoxication increase. Anxiety and motor excitement, characteristic of the initial period of mediastinitis, are soon replaced by adynamia, sometimes confusion.
The leading local symptom of mediastinitis is intense chest pain, which increases during swallowing and tilting the head back. With anterior mediastinitis, the pain is localized behind the sternum, with posterior – in the epigastric region or the interscapular space. Patients tend to take a forced position – half-sitting with their head bowed to the chest, thus facilitating breathing and reducing pain. There is swelling of the face, neck and upper half of the trunk, subcutaneous emphysema, dilation of superficial veins, cyanosis of the skin.
Severe intoxication with mediastinitis causes cardiac disorders: pronounced tachycardia (up to 110-120 beats. in min.), arrhythmia, a decrease in blood pressure and an increase in CVD. Compression of the mediastinal nerves, vessels, trachea and esophagus by edematous tissue is accompanied by the development of suffocation, persistent cough, dysphonia, dysphagia.
The lightning-fast form of acute mediastinitis leads to the death of patients during the first 2 days. It is characterized by scant local manifestations and severe general intoxication. In chronic aseptic mediastinitis, symptoms are associated with the development of sclerosis and scarring of mediastinal fiber, compression of mediastinal organs. Clinically, this can be expressed in the occurrence of asthma attacks and hoarseness of voice, the development of superior vena cava syndrome or Gorner syndrome.
Chronic microbial mediastinitis occurs in the presence of an encapsulated abscess in the mediastinum, around which a reactive scar process subsequently develops. At the same time, there is a prolonged subfebrility with periods of increasing and decreasing temperature, sweating, weakness, moderate chest pain. With the development of compression syndrome, cough, shortness of breath, voice disorders, dysphagia are added.
Diagnostics of mediastinitis
Early recognition of mediastinitis presents great difficulties. It is necessary to study the anamnesis in detail and conduct a thorough analysis of the clinical picture. When examining a patient for mediastinitis, the presence of objective symptoms may indicate: increased pain when pounding on the sternum, pressing on the spinous processes of the vertebrae, tilting the head; pasty in the sternum and thoracic vertebrae; swelling and crepitation in the jugular cavity and above the collarbone; compression syndrome of ERW, etc. Physical examination is supplemented by instrumental:
- X-ray. A thorough X-ray examination is carried out (chest X-ray, tomography, esophageal X-ray, pneumomediastinography). Radiologically, mediastinitis may reveal the expansion of the neck and mediastinal shadow, mediastinal emphysema, pneumothorax, hydrothorax, fluid level in the mediastinum, esophageal fistulas.
- Endoscopy. If esophageal perforation is suspected, esophagoscopy (EGS) is indicated; if tracheal and bronchial injuries are likely, bronchoscopy is indicated. The presence of pleural and pericardial effusion makes it possible to detect ultrasound of the pleural cavity and pericardium. In recent years, transesophageal ultrasound has been used to diagnose mediastinitis.
- Diagnostic operations. Of the invasive methods of examination, diagnostic fine-needle puncture of the mediastinum is resorted to, followed by microbiological examination of the punctate, mediastinoscopy, diagnostic thoracoscopy.
In the first day from the moment of development, mediastinitis should be differentiated from pneumonia, pericarditis, pleurisy, acute abdomen.
Treatment of mediastinitis
Conservative therapy
The basic principles of the treatment of mediastinitis are the appointment of early massive antibiotic therapy, the implementation of adequate drainage of purulent foci, radical surgical removal of the cause of mediastinitis. In order to combat intoxication, active infusion therapy, correction of water-electrolyte and protein balance, symptomatic therapy, extracorporeal detoxification, hyperbaric oxygenation, intravenous, intra-arterial, endolymphatic administration of antibiotics are carried out.
Surgical treatment
In situations of acute purulent and traumatic form, mediastinotomy and mediastinal rehabilitation are indicated. With upper anterior mediastinitis, cervical mediastinotomy is performed; lower anterior – extraperitoneal anterior mediastinotomy; with anterior spillage, a combination of supra- and sub-thoracic approaches is used.
Drainage of the upper posterior mediastinitis is carried out by cervical access; lower posterior – transdiaphragmatic (extrapleural) access; diffuse posterior – transpleural access (lateral thoracotomy). In case of esophageal perforation, gastrostomy or esophagostomy is performed simultaneously with mediastinotomy. To sanitize the mediastinum, active aspiration, washing of the mediastinum with antiseptics, administration of antibiotics and proteolytic enzymes are carried out.
In the early stages (from 12 to 24 hours after the development of mediastinitis), defects in the wall of the bronchi or esophagus are sutured, the pleural cavity and mediastinum are drained. In the later period, the perforating holes are not sutured. In postoperative mediastinitis, which occurs in cardiac surgery, resection of the sternum, removal of necrotic tissues, mediastinoplasty with flaps from the large pectoral muscles, omentum or rectus abdominis is performed.
In case of closed mediastinal ulcers, transthoracic puncture and washing of the abscess cavity or opening of the abscess and its management in an open way are resorted to. It is necessary to eliminate the causes that cause mediastinal compression and support the inflammatory process. In chronic mediastinitis of a specific etiology, active treatment of syphilis, tuberculosis, mycoses is indicated.
Prognosis and prevention
The prognosis of mediastinitis is always very serious. The outcome of the disease is influenced by the nature of the underlying disease or injury, the timeliness of the recognition of disease, the adequacy of surgical intervention and the correctness of the postoperative period. In acute purulent mediastinitis, the mortality rate reaches 70%.
The ways to prevent mediastinitis consist mainly in the prevention of iatrogenic injuries and intraoperative wounds of mediastinal organs, timely diagnosis and rational treatment of diseases leading to mediastinitis.
Literature
- Acute Descending Mediastinitis: An Unusual Presentation. Elagami MM, Ghrewati M, Sharaan A, Elzomor T. Cureus. 2022 Jul 26;14(7):e27302. link
- Descending necrotizing mediastinitis: surgical treatment via clamshell approach. Ris HB, Banic A, Furrer M, Caversaccio M, Cerny A, Zbären P. Ann Thorac Surg. 1996 Dec;62(6):1650-4. link
- Anatomy, Thorax, Mediastinum. Stoddard N, Heil JR, Lowery DR. 2022 Jul 25. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan link
- Multimodality Imaging of Focal and Diffuse Fibrosing Mediastinitis. Garrana SH, Buckley JR, Rosado-de-Christenson ML, Martínez-Jiménez S, Muñoz P, Borsa JJ. Radiographics. 2019 May-Jun;39(3):651-667. link
- Aggressive and progressive fibrosing mediastinitis involving the thoracic spine mimicking malignancy: A case report. Kang H, Jung MJ. Radiol Case Rep. 2019 Feb 12;14(4):490-494. link