1. THE CHEST WALL & Mediastinum
Dr. Muthanna Al-assal
Thoracic & Cardiovascular Surgeon
Lecturer at Alkindy medical school
Baghdad Unv.

2. diseases of the chest wall
Congenital abnormalities
are often incidental findings of CXR (bifid rib) but there are some important exceptions.
The Cervical rib. This rib is often a fibrous band originating from the seventh cervical vertebra and inserting onto the first thoracic rib.
It may be asymptomatic but because the axillary artery and brachial course over it a variety of symptoms may occur. lower trunk of the plexus (mainly T1) is cornd leading to wasting of the interossei and altered sensation in the T1 distribution.
Compression of the axillary artery may result in a poststenotic dilatation.
with thrombus and embolus formation. Treatment is by division or removal of the rib by a supraclavicular,posterior or axillary approach.
Pectus excavatum.
Pectus carinatum (pigeon chest).

3. Pectus excavatum
Is the most common congenital deformity of the anterior wall of the chest, in which several ribs and the sternum grow abnormally. This produces a caved-in or sunken appearance of the chest. It is usually present at birth and progresses during the time of rapid bone growth in the early teenage years, but in rare cases does not appear until the onset of puberty.

4. Pectus excavatum is sometimes considered to be cosmetic, however it can impair cardiac and respiratory function, and cause pain in the chest and back. People with the abnormality may experience negative psychosocial effects, and avoid activities that expose the chest.

5. Signs and symptoms
The hallmark of the condition is a
- sunken appearance of the sternum.
- The heart is displaced (and rotated).
- Mitral valve prolapse may also be present.
- Base lung capacity is decreased.

6. Tumours of the chest wall
These can be tumors of any component of the chest wall, i.e. bone, cartilage & soft tissue.
The most common tumour is that of the rib (chondroma or osteoma) and presentation is as a hard swelling over the rib.
Malignant tumours are painful end destructive and require wide resection. Even so, there is a tendency for tumours to recur and histological classification is difficult.
Tumours of the sternum are usually malignant.
Lung & pleural tumours may involve ribs and destroy them.
Most lesions may be seen on a chest radiograph but occasionally CTscan or isotope bone scanning is required.

7. Excision biopsy is often the best way to deal with a rib neoplasm because the differentiation between benign and malignant growths may be difficult. This avoids the risk of ‘spillage’ and tumour seeding in the wound of an incision biopsy.
If a major resection is to be planned, it may be preferable to know the nature of the lesion before surgery.
The principle of surgery is to remove the rib along with the rib immediately above and below, and for a length well from the margins of the tumour.

8. Reconstruction is possible using a prosthetic material (Marlex or acrylic mesh) to provide some stability to the chest wall. Myocutaneous flaps are occasionally employed to more extensive tissue defects and therefore prior ;discussion with a plastic and reconstructive surgeon may be useful.
For lesions that are not amenable to resection, chemotherapy or radiotherapy, although unlikely to be curative, may provide symptomatic relief.

9. Infections of the chest wall
These are unusual but may occur following osteo­myelitis of the underlying rib.
An empyema of the underlying thoracic cavity may discharge through the chest wall (empyema necessitans) leaving a chronic sinus.
Sterile pus should arouse the clinician that tuberculosis is present.
Treatment of the chest wall infection depends on adequate treatment of the underlying condition

10. The Mediastinum

11. Mediastinum :- It is part of the chest , which is bounded above by the thoracic inlet , below by the diaphragm , anteriorly by the sternum , posteriorly by the dorsal vertebrae , and laterally by mediastinal pleura .It is divided by a transvere plane between the angle of Lewis anteriorly and the lower border of the 4th. Dorsal vertebra posteriorly into superior and inferior medistinum ,and the inferior medistinum is further subdivided by the presence of the pericardial sac into anterior , middle and posterior mediastinum
Mediastinal tumors or cysts occur in a chracterstic location so a mass in the superior medistinum is mostly thymoma or lymphoma ,while a neurogenic tumor occur mostly in the posterior mediastinum .Pericardial cyst or bronchogenic cysts occur in the middle mediastinum .

12. Mediastinitis
Causes :- 1-Perforation of the esophagus or leakage from anastomosis . 2-Extension from a nearby infection (lung , vertebra ,pleura ). 3-Following median sternotomy for cardiac surgery . Clinical manifestations :- Fever , tachycardia , chest pain Barium swallow is useful to demonstrate esophageal perforation. Esophagoscopy will confirms the perforation . Chest X-ray & CT –scan of great value in the diagnosis . Treatment :- 1-Treatment of the cause . 2-Antibiotics according to culture and sensitivity . 3-Tube thoracostomy to drain any pleural collection . 4-Supportive therapy .

13. Superior Vena Cava Obstruction
A number of benign and malignant lesions involving the mediastinum may lead to obstruction of SVC with the production of the classical syndrome Which characterizes by elevation of the venous pressure and edema of the face , neck and upper extremity with the appearance of the dilated venous chandelles in the chest wall and cyanosis .It may be caused by the carcinoma of the lung and in (25%) of the cases ,it may be caused by a benign lesion such as idiopathic mediastinal fibrosis .