Thoracic Outlet Syndrome
Several weeks ago my husband came home with a very swollen right arm and bluish hand, my immediate thought was ‘snake bite’ as he’d been working around the farm shifting hay! Luckily this was not the case and a trip to the GP had us off to Perth for scans which confirmed a very large ‘blood clot’ or DVT (deep vein thrombosis) in one of the main veins from the arm to the chest. The swelling was caused by the blood in the arm not being able to get back to the body as the vein was very well blocked!
The official diagnosis was Venous Thoracic Outlet Syndrome, also know as Paget-Schroetter Syndrome and we are thankful that 2 weeks later he was home, a bit sore but will make a full recovery and most importantly return to bowls!
The treatment for this type of TOS involved several days on a anticoagulant (blood thinning) drip to dissolve the clot, then ‘thrombolysis’, where a catheter is passed up the arm into the clot to help dissolve it. A stent or balloon was then used to open up the vein where it was narrowed.
Once the clot was dealt with, surgery was required to resected part of the first rib (a piece removed) to prevent further compression on the nerves and blood vessels. The first rib runs from the top of the sternum, under the collar bone and around to the spine at the base of the neck. Some people have an extra or ‘cervical’ rib which can compress the thoracic outlet as well.
What is the ‘Thoracic Outlet’ ?
The Thoracic Outlet is the space between the upper chest and lower neck where a group of nerves and blood vessels pass from the thorax into the arm. It’s bordered by the collarbone above, first rib below and muscles on the sides. If the structures passing through this space are compressed, the symptoms that result are referred to as ‘thoracic outlet syndrome’ (TOS).
Types of TOS
Neurogenic thoracic outlet syndrome: Compression or irritation of the ‘Brachial Plexus’ nerves passing from the neck to the arm can cause pain, tingling, numbness and muscle weakness in the arm and the hand and occasionally the chest and neck. More than 90% of TOS cases are neurogenic.
Venous thoracic outlet syndrome: This condition is caused by compression of the major veins in the arm and lower neck. The condition develops suddenly, often after unusual and tiring exercise of the arms. Symptoms include swelling of the hands, fingers and arms, as well as heaviness and weakness of the neck and arms. The veins in the anterior (front) chest wall can also appear dilated (swollen). This accounts for around 5% of TOS
Arterial thoracic outlet syndrome: Very rare less than 1% of cases, this type of TOS is usually caused by congenital (present at birth) bony abnormalities in the lower neck and upper chest. Symptoms include cold sensitivity in the hands and fingers; numbness, pain or sores of the fingers; and poor blood circulation to the arms, hands and fingers.
What Causes Thoracic Outlet Syndrome?
Intermittent compression of the nerves and blood vessels which may be due to repetitive postural, occupational or sporting forces (Watson et al. 2009). If this causes trauma to the vein, a clot may result, this can form quite slowly over time until the blood flow is blocked and the arm becomes swollen, as in our case, which is luckily very rare. We are suspicious that the repeated action needed to operate the sheep feeder (leaning out of the ute window with the right arm and pulling on a rope – hard!- to open and close it) may be the culprit. Needless to say action has been taken to rectify this with the purchase of an electric open close control inside the ute cabin.
Treatment for TOS will vary greatly depending on the structures causing the compression. Please consult your Doctor or Physiotherapist for specific advice or treatment.