Removal of the thymus is often needed for a tumour (thymoma) or the neurological condition Myasthenia Gravis. A Thymectomy can usually be performed robotically thereby avoiding splitting the breastbone (sternotomy).
The thymus is a soft organ without a distinct structure, located behind the breastbone (sternum). Its main function is to aid the immune system in maturing the specialised white cells which are termed ‘T’ cells (‘Thymic’ cells). It is large during infancy and slowly becomes smaller with age.
Robotic thoracic surgery has been a major innovation in the treatment of thymic tumours, myasthenia gravis, and other tumours of the chest. Prior to the advent of the surgical robot, these operations would usually be performed with very large and painful incisions – a sternotomy (splitting the breastbone) or thoracotomy (an incision between the ribs). These major incisions can result in significant pain, blood loss, and a prolonged recovery increasing the time in hospital and delaying the returning to all the usual activities of daily living by up to 4-6 weeks. Robotic resection gives the surgeon excellent exposure without the need for large incisions, meaning less pain and a far quicker recovery.
Robotic Surgery avoids the need for splitting the breastbone.
There are two major indications for thymectomy. These include tumours of the thymus (thymoma), and/or the neurological condition Myasthenia Gravis. Thymic tumours are usually diagnosed by a CT scan of the chest for other reasons, such as investigation of chest pain or shortness of breath. A biopsy may be performed using local anaesthetic to determine the nature of the tumour. In many cases however a biopsy is contra-indicated or not feasible, and so surgery is planned without a definitive diagnosis. In these cases, surgical removal provides the diagnosis (a specialist pathologist analyses the tumour in the laboratory) as well as the treatment at the same time.
Myasthenia Gravis is the other common indication for a thymectomy. This is a neuromuscular condition that causes weakness of skeletal muscles due to autoimmune antibodies produced by the thymus which attack the muscle receptors responsible for contraction. The symptoms include tiredness particularly later in the day, muscle weakness, and can include double vision as the weakness can involve the muscles that move the eye.
Following referral to Dr Bassin, he will review your imaging in detail which in the first instance is usually a CT scan of the chest. A consultation is then booked and Dr Bassin will meet you in person or via telehealth for rural or interstate patients. A number of tests are then ordered to clarify the nature of the thymic tumour. These can include: blood tests, repeat CT chest with contrast, MRI of the chest, and in some cases a biopsy.
What is involved?
The thymus can be removed robotically depending on the size and location of the tumour. Usually tumours up to 7 cm or larger can be removed robotically depending on the location. In almost all cases of myasthenia gravis a robotic thymectomy is feasible, as the thymus is often small and easily accessible.
Dr Bassin uses the Da Vinci Xi surgical robot for all robotic chest surgery. This involves placing up to four 7 mm ports in between the ribs on one side of the chest. The lung on that side is deflated and the robotic instruments are then used to remove the thymus/thymic tumour. The robotic approach gives the clearest view of the chest and can assist in preventing injury to major structures including the phrenic nerve which innervates the diaphragm and is responsible for breathing. The surgery takes anywhere between 1 and 3 hours and patients can generally be discharged 2 days after surgery.
The alternative approach for thymectomy when a robotic approach is not possible is a median sternotomy – splitting the breastbone. This is the same approach used for open heart surgery and provides excellent exposure of the thymus and the surrounding structures. Although a very safe and well tested technique, the sternotomy is associated with more pain and blood loss, a longer hospital stay, and the risk of sternal infection. Dr Bassin is a very high volume robotic thymectomy surgeon and can remove the thymus robotically in the majority of cases subject to review of the imaging and clinical examination.
What is the recovery like?
When can I drive?
Patients can generally drive 1 week following a robotic thymectomy and 4 weeks if a sternotomy is required. Dr Bassin will give you individualised advice on return to driving and work.
What are the benefits and risks of this procedure?
The major benefit and reason to perform a thymectomy is to remove a tumour that either is cancerous or can transform from a more benign to a malignant tumour. Thymomas can continue to grow and eventually spread, and non-surgical forms of treatment such as chemotherapy and radiotherapy are not as effective as a complete surgical resection.
The risks of a thymectomy include: infection, bleeding, a very low risk of mortality, ongoing pain, and damage to surrounding structures including the heart, major blood vessels, the lungs, and important nerves (phrenic nerve and recurrent laryngeal nerve). A Robotic approach has a very low risk of requiring a sternotomy because the tumour is more aggressive than anticipated, or if there is injury to a major blood vessel. The benefits of the robotic approach including reduced trauma, reduced bleeding, reduced pain, and a more rapid recovery.