Health & Disease Info
All You Wanted to Know About ... Thoracic Outlet Syndrome

What Causes Thoracic Outlet Syndrome (TOS)?
Symptoms are predominately neurologic in origin due to compression of the brachial plexus. This nerve is made up of many nerve fibers that originate from several levels of the spinal cord in the area of the neck. These nerves combine to form one large nerve trunk just before it passes over the upper most rib in the chest cage. Ninety per cent of all symptoms of TOS arise from nerve compression. The other symptoms can arise from compression of the subclavian artery or vein as they pass in the same area. There are several muscles attached to the first rib. There are also a number of ligaments in the area. Compression symptoms can arise from any these structures as they impinge upon the free passage of the blood vessels or nerves.

What are the Symptoms of TOS?
As stated, most of the symptoms of TOS are related to nerve compression. This causes numbness, weakness, odd sensations in the shoulder or arm especially when the arm is held above the head or rotated outward. Common activities such as combing the hair, reaching, or working with the arms elevated, even automobile driving when hands are placed on top of the steering wheel will bring on the symptoms. Also, since the nerves are irritated, many times the muscles of the neck and shoulder will go into spasm leading to muscle aching and many times to headache. When the artery is compressed the arm tires easily and in extreme cases there many be signs of blood clots to the hand or fingers. If the vein is compressed it can clot, leading to severe swelling and a blue discoloration of the arm.

How is TOS Diagnosed?
This is a difficult diagnosis to pin down. The history obtained from the patient is most helpful. Aside from symptoms as stated above, there is many times a history of some type of trauma which could cause muscle spasm in the neck area and elevate the first rib leading to the compression symptoms. The physical examination has several features which strongly suggest TOS. Diagnostic studies are not usually diagnostic however. Many are ordered just to rule out another cause for the complaints, but there is no one study that will definitively confirm or deny the diagnosis. X-rays of the neck and chest may be done to rule out a bony abnormality or possible tumor. Nerve conduction studies will sometimes give an indication if there is compression of a nerve slowing the conduction of electrical signals and where this compression is likely to be. X-rays of the arteries and veins are rarely ordered and are indicated only if vascular compromise is suspected. Sometimes an MRI (Magnetic Resonance Imaging) test can show compression of a nerve root. Unfortunately, none of these studies are really reliable so the diagnosis is usually made by the history and physical examination.

How is TOS Treated?
Regardless of whether symptoms arise from nerve or blood vessel compression, the treatment is designed to relieve that compression. There are basically two approaches. Exercises designed to strengthen certain muscles and improve posture so that the space thru which the structures pass is opened up as widely as possible to reduce the compression may be indicated. If the exercises are not effective after two or three months of making an honest effort to follow these directions, then a surgical approach is about all that is left to try. It must be remembered that since there is no way to prove the diagnosis of TOS, in many cases a surgical procedure must be considered to be as much a diagnostic procedure as a therapeutic one.

What is Involved with Surgery?
If surgery is recommended, we would plan to do this at the hospital on a same day admission protocol. That would mean that you would come into the hospital on the day of surgery as an out-patient, register in the out-patient surgery department, and then have an IV started and an interview with the anesthesiologist. Following this you will be taken to the Operating Room holding area and then into the Operating Room to meet our operative team. Once anesthesia is induced an incision would be made under the arm just below the hair line and extending from the back muscle to the chest muscle ridge. This incision is deepened to the chest wall which is then followed upward to the first rib. The rib is then removed freeing up all of the muscle and ligament attachments to it. This leaves the vessels and nerves lying free without compression. Most patients will have an excellent result with complete relief of symptoms. Some will be improved, but will still have some complaints. A few will be no better. Unfortunately, with the healing process, scarring and adhesions form which may again compress the structures causing a recurrence of some symptoms. This does not happen frequently, but it is a real problem when it occurs.

What are Some of the Complications of Surgery?
Problems associated with your anesthetic will be discussed with you by your anesthesiologist.

Since the operation involves working around some vital structures, the complications can be quite serious. An injury to the artery, vein, or especially the nerve can cause temporary or even permanent problems with the involved arm. While this is a very unusual problem, it is extremely serious if it occurs. Also, in resecting the 1st rib one can enter the chest and deflate the lung. This is also unusual, but requires a chest tube to re-expand the lung should it occur. Obviously bleeding, infection, and would healing problems can occur as they do in any surgical procedure. Also, you will be asked to restrict the motion of your shoulder during healing of the wound. You may develop some shoulder stiffness and limitation of mobility at this time and require physical therapy to return to a normal range of motion.

We hope this information has been useful in helping you understand thoracic outlet syndrome. The information given includes the basic principles that you need to understand what is going on in your body and how we would propose to fix it. If you wish to discuss it in more detail, we will be happy to accommodate you. We have found from experience that a well informed patient is better able to cooperate with their therapy and will have a quicker and smoother recovery.