The mediastinum is an anatomic description of the central portion of the chest. Mediastinal surgery represents any procedure performed within this area. The mediastinum is surrounded by the breastbone in front, the spine in back, and the lungs on each side (Figure). The types of surgery range from small procedures performed to diagnose disease processes as well as more significant operations necessary to remove larger tumors that grow in this region. Why is mediastinal surgery needed?Many types of growths (tumors) occur in the mediastinum. These can range from non-cancerous (benign) to cancerous (malignant). It can sometimes be difficult to distinguish between benign and malignant conditions. Obtaining a piece of the tumor (biopsy) can differentiate between benign and malignant growths and allow appropriate treatment. Some benign and many malignant tumors are best treated by surgical removal (resection) although this varies by the type of tumor. Some tumors are best treated by chemotherapy or radiation therapy and do not require removal. Your surgeon will help guide you in this decision. Some diseases such as Myasthenia Gravis, a disease affecting a patient’s strength and vision, can be treated by removal of the thymus gland which resides in the mediastinum. Who is a candidate for mediastinal surgery?Most tumors that grow in the mediastinum should be biopsied or removed. Most biopsies can be performed with minimally invasive techniques and rapid recovery. Almost all patients are candidates for biopsy while candidacy for resection depends on the size of the tumor, its location, relationship with other structures in the chest and a patient’s overall medical condition. What tests are performed before mediastinal surgery?Your surgeon will perform a thorough history and physical exam. Breathing tests are generally performed (pulmonary function tests). Blood tests are drawn that can give clues to the cause of some tumors. Additionally, imaging is performed including but not limited to:Chest x-rayComputed tomography (CT) scan of the chestMagnetic resonance imaging (MRI) of the chestYour surgeon will determine if additional preoperative tests are necessary based on the findings of these studies and your medical history. Biopsy A biopsy is the removal of a sample of tissue for examination under the microscope by a pathologist, a physician trained in examining this tissue. The following are biopsy techniques: Percutaneous biopsy – Performed by a radiologist, this procedure is completed using a computed tomography (CT)-guided needle biopsy while a patient is awake but sedated. During the procedure, a needle is placed between the ribs to sample the mass. Mediastinoscopy with biopsy – Performed under general anesthesia, mediastinoscopy is a minimally invasive method to examine the mediastinum and sample tissue. A mediastinoscope (small lighted instrument approximately an inch in diameter) is inserted through a small incision at the base of the neck or between the ribs in the front of the chest. Mediastinoscopy accurately and safely diagnoses almost all tumors and is typically performed on an outpatient basis. Thoracoscopic biopsy (Video-Assisted Thoracic Surgery) – A procedure performed in the operating room under general anesthesia, this procedure uses video-assisted technology that maximizes visualization while minimizing trauma. A thoracoscope (small video-scope) and specially designed instruments are inserted through small incisions between the ribs to biopsy masses and sometimes remove them completely. Surgical ResectionSome tumors of the mediastinum require complete removal. Techniques to remove them include: Sternotomy – Division of the breastbone, identical to what is performed in open-heart surgery . A sternotomy allows access to the entire chest cavity including the heart, great vessels and lungs, and may be necessary to remove larger tumors and masses. Thoracotomy – An incision between the ribs. Similar to a sternotomy, this procedure allows wide access to the right or left chest and removal of large tumors that are localized to one side or the other. Minimally Invasive SurgerySome tumors of the mediastinum are amenable to less invasive approaches. This depends on the type, size and location of the tumor. Minimally invasive approaches include: Video-assisted thoracic surgery (VATS) is a procedure that uses video-assisted technology to minimize trauma and speed recovery. A small camera is inserted between the ribs and two other instrument “ports” utilized to manipulate and remove the tumor. Robotic SurgeryRobotic surgery utilizes robotic technology to minimize surgical trauma. The surgeon works at a console next to the patient in the operating room that provides visualization of the inside of the chest and control of highly responsive robotic arms. Advantages include 3-D technology to visualize and fine robotic dexterity to manipulate and remove tumors. Your surgeon will discuss with you and choose the best approach for your tumor.