A thymectomy is an operation to remove the thymus

Thymus

The thymus is a specialized organ of the immune system. The thymus produces and "educates" T-lymphocytes , which are critical cells of the adaptive immune system....

. It usually results in remission of myasthenia gravis

Myasthenia gravis

Myasthenia gravis is an autoimmune neuromuscular disease leading to fluctuating muscle weakness and fatiguability...

 with the help of medication including steroids. However, this remission may not be permanent.

Surgical approaches

There are a number of surgical approaches to the removal of the thymus gland: transsternal (through the breast bone), transcervical (through a small neck incision), 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. It is espoused by surgeons such as Alfred Jaretzki and is the most commonly performed procedure due to its relative simplicity.

• The transcervical approach is a less invasive procedure that allows for removal of the entire thymus gland through a small neck incision. It has been popularized by Joel Cooper. Because of its increased technical demands, it is performed by only a relative few surgeons in North America: Joel Cooper (University of Pennsylvania; Philadelphia, Pennsylvania), M. Blair Marshall (Georgetown University; Washington, DC), Bryan Meyers (Washington University; St. Louis, Missouri), Stephen Cassivi (Mayo Clinic; Rochester, Minnesota), Sudhir Sundaresan (University of Ottawa; Ottawa, Canada), Shaf Keshavjee (University of Toronto; Toronto, Canada).

Interestingly, there has been no difference in success in symptom improvement between the transsternal approach and the minimally invasive transcervical approach.

Video assisted approaches have been described.

Impact of thymic loss

A thymectomy is mainly carried out in an adult. This is because the thymus loses most of its functional capacity after adolescence, but does retain a small portion of its function during adulthood. This is shown in the decreasing size of the thymus with increasing age after adolescence.

The role of the thymus prior to adolescence is for the processing and maturation of lymphocytes, which are released into the circulation and become T-lymphocytes. They then populate the lymphoid organs for storage until needed. Removal of the thymus as an adult has little immediate effect on the immune system as its role has been completed.

Thymic hypoplasia as may be seen in DiGeorge Syndrome

DiGeorge syndrome

22q11.2 deletion syndrome, which has several presentations including DiGeorge syndrome , DiGeorge anomaly, velo-cardio-facial syndrome, Shprintzen syndrome, conotruncal anomaly face syndrome, Strong syndrome, congenital thymic aplasia, and thymic hypoplasia is a syndrome caused by the deletion of a...

 results in no T-cell education, and therefore a severe compromise in T cell mediated and humoral responses.