"Thorax" means "chest", "outlet" means "opening". The word thoracic outlet therefore refers to the upper thoracic opening around which the first rib runs. It originates at the side of the first thoracic vertebra.
Many patients have another rib above the 7th cervical vertebra. This rib is called the "cervical rib". It can be stump-shaped or long and then additionally surround the upper thoracic opening.
Nerves, called "nerve roots", emerge laterally from the bony cervical spine through certain bone openings. The 5th to 8th cervical nerve roots are responsible for the motor and sensory supply of the arm and hand.
After emerging laterally from the cervical spine, these nerves have a very complex anatomical course. The nerve structures are distributed in a braided pattern, so that this nerve region is also called the "brachial plexus" ("brachialplexus").
The parts of this plexus that emerge far down from the cervical spine are responsible for
- the small muscles in the hand and
- feeling, pain and temperature sensation in the hand on the little finger side.
The ribs in the human rib cage © bilderzwerg | AdobeStock
It is precisely these nerves that can be irritated by anatomical structures at the thoracic outlet. Although these structures are present from birth, they may become disruptive in the course of life. Why and how such a development occurs is not known.
People with very narrow chests and long, high necks are more likely to develop thoracic outlet syndrome. Presumably, the specific steep course of the nerves favors this.
Vascular impairment in isolation or in combination with the nerve symptoms is also possible in thoracic outlet syndrome. Arterial constrictions caused by arm posture can result in clots and trigger embolisms in finger arteries.
Very rarely, the blood supply to the brain is tapped. This can cause attacks of dizziness or fainting. Clots in the arm vein are even more dangerous.
The nerve symptoms of thoracic outlet syndrome are usually felt as electrifying. They radiate into the hand on the little finger side and can be extremely unpleasant.
Many patients do not feel understood by their doctor. Doctors often diagnose psychological problems as the cause of the symptoms. This results in long periods of suffering.
There is no drug therapy. According to affected patients, painkillers of any kind have hardly ever worked.
Nerves in the area of the thorax © SciePro | AdobeStock
Once the symptoms of thoracic outlet syndrome have occurred, physiotherapy is virtually ineffective.
At best, a change in posture is helpful in the case of purely nervous symptoms. In this way, the patient can try to position the structures located in the upper thoracic opening so that they are no longer irritated.
If there are repeated problems with the blood circulation, thoracic outlet syndrome must be operated on instead.
Only a few doctors actually deal with the symptoms of thoracic outlet syndrome. Among them, opinions differ widely as to which examination methods are conclusive for the diagnosis. There are no general rules for the diagnosis of thoracic outlet syndrome that can be found in the literature. Therefore, the doctor consulted must rely largely on personal experience. However, this is unsatisfactory for the patient.
Triggering certain provocation maneuvers as part of a clinical examination is almost the most important diagnostic method. This involves the examiner applying pressure to the patient's upper clavicle with his fingers.
If this triggers the typical symptoms, this is the most impressive indication of thoracic outlet syndrome. Complicated electrophysiological examinations by the neurologist are very detailed and time-consuming in thoracic outlet syndrome. They therefore only have a supplementary function.
If only nerve symptoms are present, magnetic resonance imaging(MRI) is only used to rule out the possibility of a tumor. A herniated disc in the cervical spine may produce symptoms similar to those of thoracic outlet syndrome. This disease must be ruled out during diagnosis.
The X-ray determines the presence of a cervical rib. Currently, sonography(ultrasound examination) is gaining real importance because it can be performed with changes in the posture of the arm.
However, all these imaging techniques are not completely conclusive for arm nerve irritation in the region of the thoracic outlet.
In the case of vascular symptoms, examinations of the brachial artery and vein are essential: with the help of magnetic resonance angiography and sonography of the vessels in different arm positions, a search is made for constrictions or obstructions to blood flow.
If physiotherapy attempts are ineffective, thoracic outlet syndrome can only be treated surgically. In the case of serious vascular symptoms, surgical treatment is even unavoidable.
Such an operation is preceded by intensive discussions with the patient. The doctor thoroughly explains all the uncertainties of the operation to the patient, as well as the dangers of waiting in the event of vascular symptoms.
Thoracic outlet syndrome is very rare and various specialists are involved in the operation, including
Therefore, there are very different views on the surgical procedure and the surgical approach to be chosen.
If the brachial artery and brachial vein have free patency, an operation via the upper subclavian fossa with a relatively small incision has proved successful.
The surgeon must identify all the brachial nerves, the brachial artery and vein together. He can then identify the structure responsible for the irritation of the lower cervical nerve root. This can be
- tendinous, vertically descending structures within the cervical extensor muscles,
- a sharp inner edge of the first rib or
- a stump-shaped cervical rib that may be present.
be.
The surgeon decides what needs to be removed or partially removed in each individual situation.
There is no general rule as to how a thoracic outlet syndrome operation should be performed. It goes without saying that keyhole techniques are associated with far too great a risk of damage.
Healing of the wound region in the upper clavicular fossa should be secured with a 2 to 3-day suction drainage. In the small fat pocket after the skin has been opened, there are braided lymphatic vessels which, if torn, can lead to tissue water leakage. The suction drainage ensures
- ensures adequate adhesion of the surgical area and
- prevents unwanted accumulation of wound fluid.
Inpatient follow-up observation should therefore be ensured.
If vascular symptoms are in the foreground, thoracic surgeons choose an approach through the armpit. They then aim to remove the entire first rib in order to ensure free blood flow in the vessels.
Our own experience with the surgical approach above the collarbone has shown that this approach also achieves the goal without removing the ribs. However, there are different opinions on this and justified arguments for each view.
There is no need for follow-up treatment after thoracic outlet syndrome surgery. The patient will notice immediately the next day whether the operation was successful. Physiotherapy exercises are not necessary, as there were usually no serious neurological deficits before the operation.
Local wound treatment with massages and the like should be avoided as a matter of urgency. This could cause new irritation during the scarring process.
Due to the uncertainties in the diagnosis and indication, there is always the risk of a lack of success. Thoracic outlet syndrome surgery must not cause any additional nerve damage.
No surgeon can guarantee this, but the demands on the surgeon's duty of care and patience are very high. Only if the surgeon keeps an eye on all nerve and vascular structures at all times during the operation will no damage occur.
The literature mentions the risk to the phrenic nerve in the case of access above the collarbone. This nerve supplies the diaphragm with motor activity on one side. The procedure extends to the tip of the lung.
Both the lungs are surrounded by skin (inner pleura) and the inside of the chest (outer pleura). If the outer tip of the pleura is injured, air can pass through the surgical field into the gap between the lung and the inner wall of the chest ("pneumothorax").
The patient notices this through breathing difficulties, and the X-ray can provide the evidence. The suction drainage to be placed intraoperatively towards the tip of the lung prevents the accumulation of air in the chest.
The approach through the armpit also contains these complications. There is also a risk of damage to the lower arm nerve root. Ultimately, it all depends on how carefully the operation is performed.
Reliable statistical statements on the effectiveness of such thoracic outlet syndrome operations are few and far between. The few surgeons who deal with such damage can only express personal experience.
After lengthy discussions between patient and doctor, a relationship of trust must be established. This can lead to a discretionary decision on both sides.
Thoracic outlet syndrome is an irritation syndrome of
- nerves (neurogenic TOS) or
- brachial artery and vein (vascular TOS)
above the upper thoracic opening.
The former always affects nerves that supply the region of the hand on the little finger side. In the latter, complicated circulatory disorders develop.
This is caused by small anatomical anomalies present from birth. The resulting symptoms can largely only be treated surgically, even if
- Diagnosis,
- establishing the indication for surgery and
- and performance of the thoracic outlet syndrome operation
are associated with unavoidable uncertainties.
