Surgery of Myasthenia Gravis

Thymectomy, the surgical removal of the thymus, is essential in cases of thymoma in view of the potential neoplastic effects of the tumor. However, the procedure is more controversial in patients who do not show thymic abnormalities. Although some of these patients improve following thymectomy, some patients experience severe exacerbations and the highly controversial concept of "therapeutic thymectomy" for patients with thymus hyperplasia is disputed by many experts, and efforts are underway to unequivocally answer this important question.

There are a number of surgical approaches to the removal of the thymus gland: transsternal (through the sternum, or breast bone), transcervical (through a small neck incision), and transthoracic (through one or both sides of the chest). The transsternal approach is most common and uses the same length-wise incision through the sternum (breast bone) used for most open-heart surgery. The transcervical approach, a less invasive procedure, allows for removal of the entire thymus gland through a small neck incision. There has been no difference in success in symptom improvement between the transsternal approach and the minimally invasive transcervical approach. For patients with a thymoma, though, complete tissue removal is important, as thymic tissue can regrow. Thymomas can be malignant and are thought to be the onset of other diseases, as well, so many surgeons will only recommend the full sternotomy approach to a thymectomy.

Thymoma is relatively rare in younger (<40) patients, but especially younger patients with generalized MG without thymoma benefit, paradoxically, from thymectomy. Resection is also indicated for those with a thymoma, but it is less likely to improve the MG symptoms.