The thorax (from the Greek thôrax, chest), also called chest, is the upper part of the trunk located between the neck and the abdomen.

Structure. The thorax is made up of the rib cage and various organs (1) (2).

• Rib cage. This osteocartilaginous structure is formed at the front of the sternum, at the back of the thoracic spine (spine) composed of twelve vertebrae, and laterally of the thoracic ribs. The latter, with the curved shape giving this cage structure, are twenty-four in number, ie 12 pairs. They start from the spine and are attached to the sternum through the costal cartilage, with the exception of the floating ribs which do not attach to the sternum. Located at the bottom of the rib cage, the diaphragm delimits the chest cavity from that of the abdomen.
• Internal organs. The rib cage protects various organs including vital organs such as the lungs, separated in the center by a region called the mediastinum. This region contains the heart, esophagus, trachea and bronchi.

Chest wall. The chest wall includes the skin, subcutaneous tissue, breasts, extrinsic muscles, the rib cage and its muscles.

Innervation and vascularization. Numerous blood and lymphatic vessels as well as nerves run through the thorax (1) (2).

Protective role of internal organs. Due to its shape and constitution, the rib cage helps protect some vital organs such as the heart and lungs (2).

Vital function. Located in the thorax, the heart and lungs play an essential and indispensable role in the functioning of the organism.

Role in respiration. The main organs and muscles of respiration are located in the thorax (2).

Participation in mobility. Connected to the upper limbs and having many muscles, the thorax is involved in maintaining posture, as well as in the mobility of the trunk and upper limbs.

Chest pain. Acute or chronic, pain may be felt in the chest. Given the complex structure of the thorax, the causes of pain are very diverse, but the most worrying are of cardiac and pulmonary origin (1).

Pneumothorax. It refers to the pathology affecting the pleural cavity, the space between the lungs and the rib cage. It is manifested by severe chest pain, sometimes associated with difficulty breathing.

Thoracic trauma. It corresponds to the damage to the thoracic cage due to a shock to the thorax (3).

Deformities of the chest wall. The thorax can undergo a deformation of its wall (4) (5).

Tumors of the chest wall. Primary or secondary tumors can develop in bone or soft tissue (6).

Bone pathologies. The rib cage can be the site of the development of bone diseases such as osteoporosis.

Medical treatment. Different drugs can be prescribed depending on the condition diagnosed.

Surgical treatment. In the most severe cases, a thoracotomy can be performed through an incision or opening in the thorax.

Physical examination. Diagnosis begins with a physical examination to assess the symptoms and characteristics of the pain.

Additional tests.

• Medical imaging exams. Depending on the suspected or proven pathology, additional examinations may be performed such as an X-ray, an ultrasound, a CT scan, an MRI or a scintigraphy.
• Electrocardiogram: This test is performed if the heart is suspected.

The surgeon Ferdinand Sauerbruch (1875 – 1951) was the pioneer of thoracic surgery. In 1904, he invented a process allowing open chest operations while preventing the lungs from collapsing (7). More recently, in 2014, a team from the Saint-Etienne University Hospital succeeded in replacing the aortic valve of a patient exclusively endoscopically, without opening the thorax (8).