1.What is the Thoracic outlet syndrome?

The thoracic outlet syndrome [TOS] is a condition caused by compression of the nerves or the vein and artery that emerge from the chest at the root of the neck. The space there is quite small, as all these structures pass between the clavicle and the first rib; it is also divided in two by the scalenus muscles that are attached to the first rib. The nerves [Brachial plexus that innervates the arm] and the subclavian artery pass behind the muscles, while the subclavian vein passes in front of them. As the space is tight, changes in position can cause symptoms of compression and irritation even in people that do not suffer from TOS [i.e. numbness on the arm when it is over-abducted during sleep].

2. What symptoms does it cause?

The commonest symptoms originate from compression of the nerves and comprise pain or numbness along the shoulder, the anterior or posterior aspect of the upper arm, as well as a pins and needles sensation over the fingers. The arm and hand may also be cold. Sometimes the pain may radiate to the back of the neck and the base of the cranium. These symptoms may not always be there, while they are exacerbated by exercise or lifting the arm and shoulder.

When the artery is compressed, the symptoms comprise cold hand, pain at the fingers and pain when the arm is used. If the artery becomes occluded [blocked], the symptoms become severe and permanent.

Compression of the vein gives a cyanotic appearance of the arm, with swelling, prominent veins even on the upper arm and occasionally symptoms of thrombophlebitis when the proximal vein is thrombosed.

3. Who may be affected by TOS?

TOS affects mostly young or middle aged people, especially women. The reason for is the usual  presence of a congenital anomaly in the thoracic outlet, in form of an aberrant [extra, supernumerary] cervical rib [0.5-1% of the population, but not always causing ssymptoms], anomalous insertion of the scalenous muscles or presence of fibrous bands. Trauma of the neck [hyperextension injury] may also cause acute TOS.

4. How is TOS diagnosed?

The presence of the specific symptoms mentioned earlier guides your doctor to the diagnosis. A neurological examination [positive Tinel test with tapping along the course of median nerve] and a vascular assessment [Allen test, by abduction of the arm at 90° with rotation of the head to the opposite site or movement of the hand for 3min, is positive when the radial pulse disappears or the symptoms are elicited] are essential. However, various other tests will be needed:

·   X-ray of the chest, neck, shoulder may reveal the presence of a supernumerary cervical rib, osteoarthritis changes along the vertebrae etc.

. Nerve conduction studies [electromyogram] can reveal that the nerves are compressed or irritated, however, it is not accurate. However, it can confirm more distal sites of compression, like carpal tunnel syndrome.

·   An ultrasound scan of the arteries and the veins can slow blockages or slow flow into the vessels.

·   Arteriography, with the injection of dye into the arteries, may show that flow stops when the arm is elevated; it may also show some dilatation of the artery immediately after the compression point and signs of chronic blockage of the arm or hand arteries from small emboli [debri of clot] that usually originate from the compression point.

·   Venogram, with the injection of the dye into a hand or arm vein may show that the flow stops at the compression point, especially when the arm is elevated.

·   CT scan or MRI of the neck and shoulder. Is quite useful in confirming or excluding cervical disk prolapse.

5. What are the treatment options?

When the symptoms are mild, conservative treatment should be tried first. This entails specific exercises of the shoulder zone and avoidance of specific arm positions [like sleeping on the side with the arm elevated].

Surgical treatment is always indicated when there are symptoms from compression of the artery or vein or when the neurological symptoms are severe. The aim of surgery is to make the space at the thoracic outlet bigger, by either dividing the scalenus muscles [scalenectomy] or by removal of the fist rib. The latter is probably the procedure of choice, as it has less surgical risk and quite better long term results. When there is an aberrant cervical rib, it has to be removed at the same time. In some cases, when there is further blockage of the arteries supplying the arm, a bypass may be necessary as an additional procedure to establish good flow to the hand and upper limb.

Your 1^st Rib Resection Procedure Trough The Axilla

1. Before the operation

Please bring with you all the medications that you currently take.

Surgery involves admission to the hospital for 2-3 days [unless there are arterial problems or in acute cases] and will usually be carried out on the day after admission.

Before the operation you will be seen by the anaesthetist who will examine you, as well as by a member of the surgical team who will explain what you are not sure about. Your nurse will also explain the ward routines and will answer any questions that you may have. You will have a number of preoperative tests, including blood tests, a cardiogram and a chest x-ray [if they were not done during the pre-admission clinic a week earlier.

You will be asked to eat or drink absolutely nothing for 6 hours before the operation but you should have your medications till midnight before the day of surgery. You will be started injections of heparin, which will continue throughout your stay in hospital, in order to stop clots forming in the veins of your legs.

2. The operation

The transaxillary resection has major advantages over other approaches, as it can be done in less time, allows complete visualization of the structures and complete rib resection and the scar is cosmetically better, as the incision is done at the axillary hair line. The surgeon reaches the first rib and divides the muscles and bands inserted to it, preserving the vessels and nerves. The rib is resected fully, removing the periosteum as well to minimize recurrence. If there is a supernumerary rib, it is also resected first. The wound is closed with dissolvable stitches in most of the cases.

3. After the operation

When you wake up you will find that your arm is connected to one or two plastic tubes to provide you with fluids and to monitor your blood pressure. You will usually be returned to the recovery unit so that we can keep a special eye on you for a couple of hours. After this you will be returned to your own ward.

You will be allowed to drink after you have woken completely from the anaesthetic. The operation itself is not particularly painful, although you may need some painkillers, which will be given to you if required. On the following day after surgery you will be allowed to get out of bed and to eat normally. A repeat chest X-ray will be requested and if everything is OK you will be allowed to go home. If after a week any part of the skin stitch comes to the surface it may be removed with a pair of tweezers. If it will not pull through, cut it flush with the skin with the scissors.

4. Are there any risks?

.  Some minor bruising around the wound is common after the operation. Bruising of the chest may take several weeks to settle down.

.  There is a small risk of causing damage to the nerves as they cross the area, but the risk is minimal [<1%].

.  The commonest complications are bleeding or pneumothorax [puncture of the lung with air collecting between the thoracic cage and the lung which has to be drained].

.  The risk of wound infection is minimal.

5. What about afterwards?

.  You will usually receive an appointment to be seen in the outpatients’ clinic in 6 weeks time.

.  An ultrasound scan similar to the one that was performed before your operation may also be arranged to check if arteries and veins are working properly.

.  The prognosis is good with excellent to good results in 80-93% of cases, however, there is a 10-30% chance of the symptoms recurring after several years, due to scarring formation

.  You should continue taking aspirin for life, as long as you don’t develop any complications such as stomach ulcer.

.  You can also help by improving your general health by taking regular exercise, stopping smoking and reducing the amount of fat in your diet. All these things will help reduce the chances of further trouble from arterial disease.