Chapter 317 - Disorders of the Mediastinum

Question 1

What is contained in the anterior mediastinum?

Answer 1

“It contains the thymus gland, the anterior mediastinal lymph nodes, and the internal mammary arteries and vein.”

Question 2

What is contained in the middle mediastinum?

Answer 2

“contains the heart; the ascending and tranverse arches of the aorta; the venae cavae; the brachiocephalic arteries and veins; the phrenic nerves, the trachea, the main bronchi, and their contiguous lymph nodes; and the pulmonary arteries and veins.”

Question 3

What is contained in the posterior mediastinum?

Answer 3

“It contains the descending thoracic aorta, the esophagus, the thoracic duct, the azygos and hemiazygos veins, and the posterior group of mediastinal lymph nodes.”

Question 4

In which compartment of the mediastinum does one find pleuropericardial and bronchogenic cysts?

Answer 4

Middle mediastinum.

Question 5

Where does one find gastroenteric cysts regarding the compartments of the mediastinum?

Answer 5

Posterior mediastinum.

Question 6

Name common lesions in the anterior mediastinum.

Answer 6

Thymomas, lymphomas, teratomatous neoplasms and thyroid masses.

Question 7

Name common lesions in the posterior mediastinum.

Answer 7

Neurogenic tumors, meningoceles, meningomyeloceles, gastroenteric cysts, and esophageal diverticula.

Question 8

What is the imagiological study for intrathoracic goiter?

Answer 8

Iodine-131 scan.

Question 9

Why does one use barium studies for lesions of the posterior mediastinum?

Answer 9

Since some of the diseases of the posterior mediastinum are due to gastrointestinal disease, one can diagnose hernias, diverticula and achalasia in this manner.

Question 10

What are the main causes of acute mediastinitis?

Answer 10

Esophageal rupture or median sternotomy for cardiac surgery.

Question 11

The incidence of mediastinits after median sternotomy is 0,4-5,0%.
True or False?

Answer 11

True.

Question 12

What is the mortality rate for mediastinits after median sternotomy?

Answer 12

> 20%

Question 13

What are the main causes for chronic mediastinites?

Answer 13

Histoplasmosis and tuberculosis. Other causes include sarcoidosis, silicosis and other fungal diseases.

Question 14

Which treatment has showed to be effective in fibrosing mediastinitis?

Answer 14

“Other than antituberculous therapy for tuberculous mediastinitis, no medical or surgical therapy has been demonstrated to be effective for mediastinal fibrosis.”

Question 15

Name the three main causes for pneumomediastinum.

Answer 15

“(1) alveolar rupture with dissection of air into the mediastinum; (2) perforation or rupture of the esophagus, trachea, or main bronchi; and (3) dissection of air from the neck or the abdomen into the mediastinum.”

Question 16

What is Hamman’s sign?

Answer 16

“crunching or clicking noise synchronous with the heartbeat and is best heard in the left lateral decubitus position.”

Question 17

In esophageal rupture with pneumomediastinum, without any signs of mediastinitis, what is the treatment?

Answer 17

“Usually no treatment is required, but the mediastinal air will be abosrbed faster if the patient inspires high concentrations of oxygen. If mediastinal structures are compressed, the compression can be relieved with needle aspiration.”