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Transcervical Thymectomy for Myasthenia Gravis
Myasthenia gravis is an autoimmune neurologic disease that results
when the thymus, a normally dormant gland in the chest, begins producing
antibodies that interfere with the muscle’s ability to contract.
The symptoms may include droopy eyelids; double vision; weakness in
the face, neck, arms and legs; and/or difficulty in swallowing. Myasthenia
gravis can have a serious impact on the simple activities of daily
living.
Thymectomy
Most experts agree that removing the thymus gland (thymectomy) improves
the course of the disease by reducing or eliminating the symptoms.
However, improvement may take months or years. Thymectomies traditionally
have been performed by dividing the breastbone down the middle of
the chest, the same incision used by cardiac surgeons for heart
surgery. Because of the extent of the incision used with the traditional
approach and several weeks of recovery time, many people with myasthenia
wait until their illness has progressed before having the operation.
Minimally Invasive Transcervical Thymectomy
When the thymus is removed through a neck incision alone, the operation
is called a transcervical thymectomy. Surgeons first performed the
transcervical thymectomy in 1912 for a patient with myasthenia gravis.
A newer technique is used by Washington University thoracic surgeons.
This technique involves a 1 1/2-inch incision at the bottom of the
neck, just above the breastbone [sternum]. No bone is divided and
only the skin is cut. A special retractor was developed to perform
the surgery. This device allows the surgeon to see the thymus gland
directly from the neck without the need to open the chest. G.
Alexander Patterson, M.D., Bryan
F. Meyers, M.D., and other thoracic surgeons at Washington University
School of Medicine and Barnes-Jewish Hospital, now have performed
more than 200 of these procedures.
Contraindications of the Transcervical Thymectomy
The transcervical approach should not be used for patients with
thymoma (tumor of the thymus) and should be done only by surgeons
trained and experienced in this highly specialized procedure.
Method
Washington University thoracic surgeons perform the transcervical
thymectomy through a 1 1/2-inch incision in the lower portion of
the neck. With the use of special instruments, the surgeon is able
to see into the chest and remove the thymus gland. Because the operation
is performed through a small incision, and because no major muscles,
ribs or other bones are injured, recovery is rapid and there are
no postoperative restrictions on activity.
What to Expect
A neurologist trained in the care of myasthenia gravis evaluates
all patients considering thymectomy to assess their symptoms and
the extent of their disease. The neurologist assesses whether the
patient would benefit from a medical treatment called plasmapheresis
before undergoing surgery. In patients with severe weakness, plasmapheresis
is considered before surgery to reduce the level of harmful antibodies
in the blood. The removal of these antibodies improves muscle strength
before the operation. Patients are admitted to the hospital either
the day before surgery or the day of surgery, depending upon their
health status. The surgery takes approximately 90 minutes to complete.
Our operating room staff members specialize in thoracic surgery
and are experts in caring for the thymectomy patient. After surgery,
the patient is monitored in the recovery area until stable and then
is moved to the Thoracic Surgery Observation Unit. This unit has
nurses specially trained in the care of the thymectomy patient.
Patients are discharged directly from the observation unit to home,
usually the next day. The average time from surgery to discharge
is 24 to 36 hours. Patients have a single follow-up appointment
with the surgeon and then are released with follow-up care to be
provided by their neurologist.
Advantages of the Transcervical Thymectomy
Patients with myasthenia gravis who choose transcervical thymectomy
are more likely to have their thymus gland removed early in their
disease. Therefore, these patients’ symptoms are less likely
to progress. The standard approach to thymectomy uses a chest incision
and requires an average hospital stay of five to seven days, while
the transcervical thymectomy allows the patient to leave the hospital
the following day. Furthermore, following the transcervical approach,
patients can return to normal activities within a day or two, whereas
with the open-chest approach, recovery time is a matter of weeks.
Transcervical thymectomy patients experience less pain and fewer
postoperative complications than do patients who require the open
chest procedure.
Results
Patients have ranged from 12 to 71 years of age. Before surgery,
the patients had an average Osserman score of 2.65 (meaning they
have slight to moderate generalized weakness or swallowing difficulties).
No patient required blood transfusions or postoperative respiratory
support. Seventy-one percent of the patients had a very significant
improvement (no generalized weakness and no requirement for the
medication Mestinon). Twenty-one percent of patients showed modest
improvement, and only 8 percent showed no improvement at all.
Careful follow-up of patients undergoing the transcervical approach
has been obtained for up to 10 years. The results are equivalent
to those seen after open-chest procedures. Immediately following
the operation, the patient continues to take the same medication
as he or she was taking before the operation. However, over the
following months and years, the majority of patients regain normal
muscle strength and many experience complete remission — that
is, no weakness and no requirement for medication. The main value
of the transcervical thymectomy is to encourage the early removal
of the thymus gland in patients with myasthenia gravis, thus increasing
their chance for complete remission.
For a thoracic surgery consultation, call (888) 287-8741.
Washington University physicians are the medical staff of Barnes-Jewish Hospital and St. Louis Children's Hospital
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