Thoracic Outlet Syndrome (TOS)
All forms of thoracic outlet syndrome occur due to compression of the structures between the bones and muscle of the neck and chest. The commonest bony structure involved is the first rib, against which the structures are often compressed.
Neural thoracic outlet syndrome is usually initially treated with conservative measures including physiotherapy. In some cases if the conservative management has failed, a thoracic outlet decompression may be offered with excision of a segment of the first rib and the adjacent muscles.
For venous and arterial thoracic outlet syndrome, surgery is more commonly offered. This is usually in the form of excision of a segment of the first rib. In some cases, there are abnormal structures exacerbating the compression, such as abnormal bands or extra ribs. These are divided and removed at the time of operation on the first rib. If the artery has been damaged by the compression, then procedures to rectify this are also performed during the surgery.
The operation is performed under general anaesthetic.
Depending on the pathology and structures compressed, the first rib can be excised through several incisions. These incisions are usually made either in the armpit or above and possibly below the collar bone. The selection of the incision will be discussed with you before the surgery.
The muscles of attached to the thoracic inlet structures and the first rib are carefully dissected out. The nerve to the diaphragm and muscles for breathing called the phrenic nerve is carefully dissected free and preserved. The vessels are identified and protected. The first rib is identified and carefully separated from the attached muscles. A bone nibbler is then used to carefully excise several centimeters of the first rib and provide a space for the previously compressed structures to shelter. Haemostasis then checked and a small drain inserted before careful closure.
Complications are uncommon but include anaesthetic complications, infection, bleeding, an air leak in the chest (called a pneumothorax, which can require an extra drain tube), damage to the nerves to the hand and diaphragm, and a leak of clear fluid called a lymph leak. Rarely, a return to the operating theatre is required.