Key Points

• A majority of patients with myasthenia gravis who undergo thymectomy improve or have complete remission of their disease over several years.
• Thymectomy increases the likelihood and duration of remission.
• Patients with myasthenia gravis and a thymoma should have their tumors completely resected in addition to a total thymectomy.
• There is strong evidence to also support thymectomy in the non-non-thymomatous myasthenic patient.
• Various surgical techniques, including transcervical, transsternal, VATS and robotic aproaches can be used to access the anterior mediastinum and resect thymic tissue.
• Careful preoperative prepartion and selection of patients with myasthenia gravis results in a safe operation with little postoperative morbidity.
• Patients with myasthenia gravis should be evaluated jointly by neurologists and thoracic surgeons.

Myasthenia gravis (MG) is an autoimmune disorder that affects skeletal muscles. Clinical symptoms range from intermittent ocular weakness to severe generalized muscle weakness to debilitating respiratory depression. This disease is primarily managed by neurologists with anticholinesterase agents (pyridostigmine and neostigmine) and immunomodulating therapies (commonly corticosteroids and azathioprine). In most patients, surgical removal of the thymus gland provides a significant additional benefit.

The rationale for thymectomy in patients with MG is based on observations that patients undergoing thymic resection have an increased chance of improvement or complete remission of their disease. Until recently, there was no prospective randomized controlled trial (RCT) comparing medical versus surgical therapy. Thus patient care decisions were at the discretion of the treating neurologist. In early 2016, however, the MGTX Study Group reported their results involving 126 MG patients who underwent randomization to transsternal thymectomy with corticosteroids or corticosteroids alone [1]. In this landmark study, patients randomized to thymectomy were found to have improved clinical outcomes and a reduction in the need for immunosuppressive therapy. These results highlight the continued importance, and possible expanded role, of thoracic surgeons in management of the MG patient.