Usually, head and neck infections are confined to a small area of cellular tissue in the head and neck and can be effectively controlled by timely incision and drainage and reasonable anti-infective treatment. However, in a few cases, such as certain anaerobic bacterial infections, strong bacterial virulence, untimely or inadequate drainage, and unreasonable application of antibiotics, head and neck infections lead to mediastinal and thoracic inflammation down through the cervical tissue spaces, resulting in serious consequences and even death. This type of infection is called downstream necrotizing mediastinitis.
1.Materials and methods
Clinical data: general data: 16 patients, gender: 11 males and 5 females; age: 3-56 years old, including 4 under 20 years old, including 2 due to purulent tonsillitis, 1 due to upper respiratory tract infection causing submandibular space infection, 1 due to abscess after fish spur lacerations in the pharynx; 1 aged 21-30 years old, etiology: pericoronitis of wisdom teeth; 9 aged 31-40 years old, etiology: pericoronitis of wisdom teeth 4, apical or alveolar abscess 2, posterior pharyngeal wall abscess 2; 41 years of age or older 3, etiology: apical or alveolar abscess 1, post-denture repair infection 1, posterior pharyngeal wall abscess 1.
Clinical symptoms and examination: early infection of the head and neck, manifested by restricted mouth opening, swelling of the jaw and neck, swollen and painful teeth or gums, and difficulty in swallowing; after 6-15 days, swelling of the neck, chest pain, shortness of breath or difficulty in breathing, even telangiectasia, etc. Fever, body temperature up to 39oC or more, and increased white blood cells. X-ray jaw surface tomography of odontogenic infection: 6 cases showed obstructed mandibular wisdom teeth and 4 cases suggested hypodense shadows in the apical or alveolar areas.
All patients underwent chest X-ray, which showed widening of the upper mediastinum, including 11 cases of pleural effusion, 8 cases of subcutaneous emphysema, and 6 cases of mediastinal emphysema. Seven cases were sent for bacteriological examination.
Treatment: Surgical treatment was used in all cases. There were 5 cases of double-lumen drainage through the cervical and upper mediastinum, 16 cases of combined closed chest drainage, and 12 cases of thoracotomy drainage, including 2 cases of extensive cervical, thoracic, and mediastinal incision and drainage. 4 cases of preoperative emergency tracheotomy. All cases were combined with antibiotics to fight infection and enhance nutrition to improve resistance. 4 cases were replaced with sensitive antibiotics according to bacteriological examination and drug sensitivity test at appropriate time.
2. Results
In all cases, there were more males than females, with a male to female ratio of 2.2:1. The etiology of odontogenic infections was more, accounting for 56.25%, especially wisdom tooth pericoronitis, which was the most common, reaching 31.25%. Age: young adults aged 21-40 are the most common, accounting for 62.5%. Early manifestations are restricted mouth opening, swelling of the face and neck, swollen and painful teeth or gums, and difficulty in swallowing, etc. The development is rapid, with symptoms of mediastinal infection such as chest pain appearing in 6-15 days, with an average of 11.5 days.
The duration of hospitalization ranged from 7 to 63 days, with an average of 37.3 days. CT is an effective adjunctive test for diagnosis and timely judgment of the disease. All patients were treated with surgical incision and drainage, 13 cases were cured and 3 cases died, cure rate: 81.25%. The causes of death were: 2 cases of infectious shock combined with respiratory failure died 7 days and 12 days after surgery, and 1 case of infectious shock combined with acute renal failure.
3. Discussion
Head and neck infection causing downstream necrotizing mediastinitis is a relatively rare infectious disease with rapid onset, dangerous condition and high mortality rate, which can reach 85% before the invention of antibiotics. Currently, although significantly reduced, it is still high, ranging from 11% to 50%. This is related to the awareness and treatment of the disease by different authors, but also closely related to the low incidence of the disease, the small number of mass cases and the large statistical differences.
However, it is undeniable that mediastinitis is one of the most serious complications of head and neck infections. In the past, there were fewer cases and limitations in the understanding of this disease. With the accumulation of cases and deeper understanding, retrospective analysis of the cases allows us to understand the disease more clearly.
3.1 Epidemiological features: The results suggest that the most frequent etiology is odontogenic infection, accounting for 56.25%. However, different scholars have different opinions, and the 17 cases analyzed by Makeieff had the most non-dental infections, accounting for 64.7%. This may be related to the different ranges of exposure to patients.
In addition, some rare etiologies causing DNM should be worthy of our reference, such as acute suppurative thyroiditis, childhood varicella infection, and steroid injection for neck pain. Our analysis shows that there seems to be a relationship between the etiology of the disease and the age of onset, with a high incidence in young adults and the most frequent odontogenic infections.
Among them, patients with pericoronitis of wisdom teeth accounted for 31.25% of the total number of cases. In contrast, non-odontogenic infections such as purulent tonsillitis and retropharyngeal abscesses before the age of 20 years became the most important causes of the disease. These features have some significance for our understanding of this disease. However, the number of cases is still relatively small, and a true statistical analysis cannot be performed, and further case accumulation is needed.
3.2 Clinical characteristics: In addition to the general manifestations of infectious diseases, it also has some special clinical symptoms, which are summarized as follows.
(1) Rapid development: it is an important feature of head and neck infection causing downstream necrotizing mediastinitis. In our cases, it ranged from 6-15 days from the head and neck infection to the determination of mediastinitis, with an average of 11.5 days. Among them, the shortest case was only 6 days. The patient was a male, 41 years old, with infection of the left submaxillary space due to periapical inflammation of the left lower first molar, which spread to the right submaxillary and floor of the mouth space on day 3. After incision and drainage of the pus in the local hospital and massive antibiotic application, he was referred to our hospital on day 6 for chest pain and telangiectatic breathing, and the diagnosis of the disease was confirmed by CT examination.
In practice, the authors found that cases with rapid development are often the most difficult to control, which may be related to the strong virulence of the bacteria. In the case mentioned above, the patient died a week after admission due to toxic shock and respiratory failure.
(2) Necrotic features: Compared to general infections, downstream necrotizing mediastinitis is often caused by anaerobic necrotizing bacteria in combination with aerobic bacteria. This type of infection often smells strongly and peculiarly foul during incision and drainage, with little pus, tissue necrosis, pneumatization and twisted pronation.
(3) Chest pain: It is an important sign of downstream mediastinal infection. All cases have early history of complaints of severe pain in the anterior thoracic region, while ENT physicians or oral and maxillofacial surgery lack awareness of the disease and focus only on focal infection management in the management of head and neck infections while ignoring this important signal of downstream infection in patients, resulting in treatment delays.
On the other hand, practice has shown that early chest X-rays in DNM often show no significant abnormalities or only a slight widening of the upper mediastinum, making the X-ray features lag behind the clinical presentation. CT can show the degree and extent of inflammation infiltration in the face and neck and mediastinum, which is an important tool for early diagnosis of DNM.
3.3 Preventive and therapeutic measures: The increased awareness of the disease and close multidisciplinary cooperation have led to a greater cure rate. In clinical practice, some special head and neck interstitial infections deserve attention: be alert to infections with rapid development, wide spread, special odor on incision, tissue necrosis and subcutaneous emphysema, and early, timely and adequate treatment can effectively prevent the occurrence of downstream necrotizing mediastinitis by.
(1) Strive for the widest possible, adequate incision for pus drainage and irrigation, and keep the wound open to avoid the creation of an anaerobic environment.
(2) Observe closely and pay attention to the patient’s symptoms such as chest pain and dyspnea, and if necessary, CT examination to understand the development of the disease.
(3) High-dose high-efficiency antibiotic application: according to the results of bacterial culture and drug sensitivity test is the most effective way to select sensitive antibiotics, but the early application of a large number of broad-spectrum antibiotics so that bacterial culture often no clear results. In recent years, the emergence of thiamphenicol antibiotics with carbapenem ring has significantly increased the cure rate of this disease. Imipenem and meropenem have strong antibacterial effects on Gram-positive and negative aerobic and anaerobic bacteria, and are currently the most effective antibiotics for the treatment of such infections, with the disadvantage that they are more expensive.
Most scholars agree that once mediastinal infection occurs, a wide incision of the neck and mediastinum should be performed under the guidance of CT examination to remove necrotic tissue from the parapharynx, retropharynx, deep cervical fascial space and mediastinum. For limited abscesses at different sites, drainage can be performed via the neck, the angle of the costal arch, the subxiphoid process or open chest, and Gorlitzer et al. used clavulotomy and vacuum negative pressure suction to perform cut-and-drainage with satisfactory results, which is worth learning from.
In order to reduce the trauma, some people adopt thoracoscopic means to perform excision and drainage and have achieved success. The author believes that the clinical approach should be based on the condition, and the appropriate surgical method should be chosen under the condition of minimizing pain and curing as soon as possible and completely.