Most people don’t know a lot about the thymus, a tiny gland that typically becomes less important as you get older. But if you have myasthenia gravis, your doctor may suggest thymectomy. That’s surgery to remove your thymus. Here’s how it works and how it might help.
What Is the Thymus and What Does It Do?
The thymus gland sits in your chest behind the breastbone. It plays an important role in the development of your immune system. Most of its job is done before you’re born and in early childhood. That’s when it makes and trains T cells, also called T lymphocytes. That’s a type of white blood cell that fights infection.
By the time you reach puberty, you have plenty of T cells. So your thymus starts shrinking and slowly gets replaced by fat cells.
The Thymus and Myasthenia Gravis
Myasthenia gravis is an autoimmune disorder, and it often overlaps with thymus problems. The exact link between the two is not fully understood. But 70% of myasthenia gravis patients have changes that suggest an immune response is happening in the thymus. And 10% have a thymus tumor, which is usually benign, meaning not cancer.
Myasthenia gravis happens when the communication between nerve and muscle cells gets disrupted. When brain cells (neurons) send out messages, they travel down to the nerves that control movement in your muscles and release a chemical called acetylcholine. Acetylcholine needs to bind to a receptor in the muscle for it to contract. Experts suspect the thymus gland makes antibodies that damage acetylcholine receptors in people with myasthenia gravis.
Why Thymectomy?
Your doctor might recommend this surgery if you’re under age 60 and have moderate to severe weakness due to myasthenia gravis. No matter your age, this procedure is probably needed if you have a tumor, even if it’s non-cancerous.
Thymectomy is often effective. Research from the National Institute of Neurological Disorders and Stroke found that people with myasthenia gravis who have this surgery (despite not having a thyroid tumor) typically see improvements in muscle weakness. They also don’t require as much immunosuppressive medication. About 50% of patients who opt for thymectomy see complete remission. That’s when you have no symptoms.
How Thymectomy Is Performed
Surgeons performing thymectomy typically use one of three main approaches:
Transsternal. Your surgeon makes a cut in the skin over the breastbone. Then they cut through the bone to get to your thymus.
Transcervical. The surgeon makes a cut right above the breastbone, across the bottom of the neck. No bone is cut.
Videoscopic (VATS). Minimally invasive options include robotic thymectomy and video-assisted thoracoscopic thymectomy (VATS). With these approaches, a surgeon makes several small cuts in the chest and uses robotic arms or other special tools (including a small camera) to reach and remove the thymus without making a large cut.
What to Expect
Thymectomy itself usually takes 2 to 4 hours, depending on the approach. Your surgeon, anesthesiologist, and neurologist should go over all the details of the procedure with you ahead of time.
You’ll stay in the hospital for a few days to a week until you’re strong enough to finish recovering at home. You’ll likely need to limit some activities and avoid lifting anything heavy for 3 to 6 weeks.
If you had a tumor, you might also need radiation and/or chemotherapy following surgery.
Though most people with myasthenia gravis improve after thymectomy, the benefits don’t kick in right away. You’ll need to continue working closely with your doctor.
Show Sources
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SOURCES:
Cleveland Clinic: “T-Cells,” “Thymectomy,” “Thymus.”
Current Opinions in Immunology: “Thymic Fatness and Approaches to Enhance Thymopoietic Fitness in Aging.”
Myasthenia Gravis Foundation of America: “Clinical Overview of MG,” “Thymectomy.”
National Institute of Neurological Disorders and Stroke: “Myasthenia Gravis.”
Northwestern Medicine: “Thymectomy.”
RJW Barnabas Health: “Thymectomy/Mediastinal Mass.”
