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Thoracic Outlet Syndrome

Description of Clinical Program

Paget-Schroetter syndrome, a subset of TOS

What is Thoracic Outlet Syndrome?

Thoracic Outlet Syndrome or TOS is a disorder of the upper extremities that can cause symptoms such as; pain, numbness, tingling, weakness, and/or swelling and circulation changes. The thoracic outlet is an area on both sides of the body behind the clavicle (collarbone), where an artery, a vein and a group of nerves cross over the first rib to continue down either arm. Problems occur when this area is compressed or made smaller. This can be from upward movement of the first rib, presence of a cervical rib or by shifting of the clavicle. This closure of the outlet can put pressure on the nerve causing symptoms of numbness, tingling and pain down the arm to the hands and fingers as well as up to the neck and head. Pressure on the artery can cause problems with blood supply to the arm, making it tired to achy especially with activity. If the vein is involved, swelling can occur with enlargement of the veins of the arm and even into the chest. A person with Thoracic Outlet Syndrome can have one, two or all of these problems. Use of the arm may be painful or difficult in any of these situations.



What causes Thoracic Outlet Syndrome?

Many things can cause thoracic Outlet Syndrome, as a number of abnormalities can develop in the thoracic outlet area. For example: Some people are born with an extra rib called a "cervical rib". Although most often this causes no particular problem, under certain circumstances the can narrow the opening in the thoracic outlet area and cause compression. Other people may be born with a smaller opening. Most frequently, the symptoms begin after an injury or accident, or after some repetitive movements such as computer work or swimming. Activities that cause enlargement of the scalene muscle, such as weight lifting, can also cause symptoms.

What are the usual symptoms of Thoracic Outlet Syndrome?

Symptoms always involve the upper extremities. Numbness, tingling, weakness and pain in the arm and hand are the most common symptoms. However, there are many other symptoms as well. Some patients have swelling of the arm and hand. Some patients only have pain if they are doing an activity that requires their arms to be raised such as brushing their hair. Temperature changes of the extremity can occur. Other symptoms that are quite common include pain in the shoulder, back, neck and head. Many people have thoracic outlet problems on both sides, although one side is usually worse than the other.

How is the diagnosis made?

The first step in getting a diagnosis of thoracic outlet is to be seen by a physician who specializes in thoracic outlet syndrome. Much of the diagnosis is based on the history the patient gives regarding the onset and progression of the pain or other symptoms as well as a detailed physical examination. There are other problems that can cause similar symptoms so an accurate history and physical are very important. If the physician feels thoracic outlet is likely, a few tests will be ordered to confirm the diagnosis. A chest X-ray is done to determine if a cervical rib or other bony abnormality is present. Several electrical tests are usually ordered. These include an electromyogram, (EMG), nerve conduction times, and somatosensory evoked potentials (SSEP). These help to determine the nerve and muscle function in the arm. A MRI of the neck and chest may be ordered to look specifically at the thoracic outlet, for evidence of compression of the nerves, arteries and veins by normal or abnormal structures and also to look at the cervical spine. If these tests indicate thoracic outlet syndrome, and if the symptoms are caused by nerve compression (not an artery or a vein) a test called a scalene block will be done. When the artery or the vein is involved, a study of the artery or of the vein with an ultrasound or angiogram may be necessary. This will usually complete the clinical diagnosis of thoracic outlet.

What is a scalene block and how is it done?

A scalene block is a specialized test that tells us if the patient indeed has thoracic outlet syndrome and if a surgical procedure will help alleviate the pain. The scalene muscles are located under the trapezius muscles in the neck and shoulders. You cannot see or feel the muscles from the outside. The scalene muscles attach to the first rib. A scalene block relaxes the scalene muscles allowing the first rib to drop and the thoracic outlet to become larger and relieve the compression. A diagnosis of thoracic outlet can be made if the symptoms improve, and examination done by the physician, at the time of the block, is confirmatory.

A neurologist usually does the scalene block. This physician may use a MRI to locate the scalene muscle. Once they are located, a numbing agent such as lidocaine is injected into the muscles causing them to relax.

Once the diagnosis is made, what do I do?

We recommend that our patients try physical therapy, a special exercise program, and a pain management program. For patients who have problems that are made worse by the work they do, we recommend that an ergonomic assessment" of the workplace be done. This assesses the placement of equipment used (such as the height of the computer), the body movements required, etc. Sometimes changes in the way repetitive motions are done can help with symptoms. If symptoms continue despite these interventions, it usually means that surgical correction of the abnormality will be recommended, to relieve the symptoms and to prevent further damage.

What kind of surgery and how is it done?

The goal of surgery is to clearly identify and correct the cause of the compression, which can be an abnormality of the tendons, the scalene muscles or the bones that make up the thoracic outlet (the first rib or clavicle). There are 2 basic operations for thoracic outlet syndrome, usually referred to as: rib resection or scalenectomy. The scalenectomy operation is designed to remove the scalene muscles that may cause some of the compression on the brachial plexus nerves. It involves an incision just above the clavicle (collarbone). The operation takes about 1-2 hours. Most patients may be discharged the following day.

The fib resection is a more involved operation. It is designed to relieve compression caused by the first rib or other structures, at the same time it requires a partial scalenectomy. It may be done through an incision above the clavicle or an incision under the arm (the axilla). It has the advantage of being more complete operation. This operation takes between 1 V2 and 2 V2 hours. Most patients will be discharged the following day.

The choice of operation is based on several factors; the clinical symptoms, the anatomical information provided by the examination and other tests, such as the x-rays and MRI. It is also important to take into account previous treatments or operations. Generally both types of operations can relieve the symptoms, although the experience of our surgeons indicates that the rib resection type of operation, being a more complete procedure, is more likely to offer longer lasting benefit.

How long is the hospitalization?

Patients come in the morning of surgery and are discharged the day after surgery.

Do I need a pre-operative visit with and anesthesiologist?

This is rarely needed unless you have other conditions such as heart disease, asthma, high blood pressure or lung disease.

Will I need a blood transfusion? It is unusual to need a blood transfusion during this surgery. For this reason we do not routinely prepare blood for transfusion. Since, with any surgery there is always the small risk for the need of an emergency transfusion, we always ask the permission to do so should the emergent need arise.

What are the complications of the operations?

As with any operation bleeding and infection are things of concern. In these operations these problems are rare. More specific concerns involve injury to the nerves and air leaking into the chest cavity. Air may leak into the chest cavity in about 10 to 15% of cases and is usually easily dealt with at the time of surgery, by using a small flexible tube for aspiration. Major nerve injury is unusual although reported in the medical literature. The artery and vein can be injured as well.

Eighty per cent of patients will have significant improvement of their symptoms following surgery. Ten per cent will have some improvement, and 10% may not improve. Some patients may also experience a recurrence of the symptoms months to years following surgery. This is usually treated by physical therapy or scalenectomy.

What can I expect during the post-operative period?

Immediately after the surgery is over you will be taken to the PACU/Recovery Room. You may spend 1-2 hours in this area as you wake up from anesthesia. Once you are stable you will be transferred up to the nursing unit. Most patients will not feel like doing much the rest of the day. You can get out of bed, sit in a chair or walk in the hall if you feel up to it. Most patients experience, in varying degrees, nausea and pain. This is normal. Medication will be ordered to help relieve you of these uncomfortable symptoms.

How will my pain be controlled?

Pain medication will be available for you. Pain pills will be ordered. Remember to ask for the medication, the nursing staff will NOT automatically bring it to you. Sometimes a machine, called a PCA (Patient Controlled Analgesia), will be ordered by the doctors. This machine administers the pain medications through your IV when you push a button. The PCA is set to give you a maximum amount of pain medication over an hour so there is not a chance that you will over medicate yourself. You will be taken off the PCA machine by the morning of your discharge from the hospital. You will then be put on pain pills. A prescription for pain medication will be given to you when you leave the hospital.

How long will my recovery be?

Most recovery periods range from 4 weeks to 6 months, although there will be variation in recovery times.

How long before I can drive?

You can drive short distances in 2 weeks provided you are not taking any narcotic pain medicine.

What will I be doing during my recovery?

No heavy lifting (anything greater than 5 pounds) is allowed until cleared by the doctor. You may be given a sling to use after the surgery. Try to limit the use of the sling to the first 48 hours after your surgery and while you are sleeping. Extended use of the sling may cause a problem recovering full mobility in your shoulder. It will be important for you to do arm exercises to prevent this from occurring. You will be taught these exercises before discharge. They include: pendulum arm swing; walking the wall; hanging circle. Do these exercises 4-6 times a day. You may be referred for physical therapy after 2-4 weeks if needed.

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