Definition and Overview

Mediastinoscopy is a diagnostic procedure designed to examine the mediastinum, the space behind the sternum (breastbone) located in the middle of the chest and right between the lungs. It contains several important structures including lymph nodes, the trachea (windpipe), the oesophagus (the tube that connects the throat and the stomach), the heart, and neighbouring structures, and the thymus gland. Mediastinoscopy is often performed to diagnose and determine the extent of several conditions including lung cancer, lymphoma, tuberculosis, and sarcoidosis.

The procedure allows the doctor to assess the organs and the important structures inside the mediastinum. The mediastinoscope takes images that are sent to a computer screen and recorded for a detailed counselling with the patient, as well as the development of an effective and efficient treatment plan.

Mediastinoscopy is a “keyhole” surgical procedure and involves a small incision on the chest. It uses mediastinoscope, a long, thin, and flexible tube with a tiny camera and a light source on one end. Aside from recording still images or videos, the specialised tool can also take blood and tissue samples from within the mediastinum for further medical evaluation.

Who Should Undergo and Expected Results

Mediastinoscopy can be recommended for patients with the following conditions or symptoms:

  • Inexplicable symptoms pertaining to a lung problem, especially when non-invasive diagnostic procedures (such as chest x-rays) have failed to yield any conclusive information
  • Suspected lung cancer
  • Suspected lymphoma, including Hodgkin’s disease
  • Certain lung infections, including tuberculosis
  • Cancer affecting the structures within the mediastinum
  • Infection or inflammation of the structures within the mediastinum
  • Thymoma, or the development of a tumour affecting the thymus gland
  • Sarcoidosis, which causes inflammation in the lungs, liver, and spleen

Patients who are about to undergo lung removal surgery (as treatment for lung cancer) typically undergo a mediastinoscopy to check the lymph nodes and determine their suitability for such an irreversible procedure. Doctors also use the vital information obtained from a procedure to develop a treatment plan for patients with lung cancer.

It is important to note that a mediastinoscopy—while considered a surgical procedure because of the incisions involved—is performed only for diagnostic purposes and is not meant to deliver treatment to the structures within the mediastinum.

How is the Procedure Performed?

Mediastinoscopy is often performed in a hospital or clinic on an outpatient basis. Before the procedure, the patient is advised to:

  • Stop the intake of certain medications that could affect the results of the procedure
  • Fast for eight hours before the procedure
  • Make arrangements for someone to bring him or her home after the procedure

The patient is then instructed to lie down on an operating table. An IV (intravenous) line is placed in the patient’s hand or arm, where general anaesthesia and fluids will be introduced to his or her system during the procedure. For the entire mediastinoscopy, the patient will be asleep and not feel pain.

A breathing tube is inserted into the throat and hooked up to a breathing machine or ventilator. The patient’s heart rate, blood pressure, and breathing are monitored during the entire procedure.

In male patients, chest hair is often trimmed to expose the skin.

The surgeon then makes a small incision right above the breastbone where a clean gloved finger is inserted to make a passageway into the mediastinum. Through this, the surgeon can examine the lymph nodes through touch.

The mediastinoscope is inserted into the incision to take images of the structures within the mediastinum as well as tissue and blood samples when and as needed. The mediastinoscope is then removed and the incision closed with sutures or adhesive strips. A sterile dressing will be placed in the area.

The samples taken from within the mediastinum are sent to a laboratory for further evaluation. The breathing tube and IV line are then removed.

Possible Risks and Complications

Because a mediastinoscopy is a surgical procedure, it comes with certain risks, which include the following:

  • Excessive bleeding
  • Infection within the mediastinum or on the site of the incision
  • Temporary or permanent paralysis of the laryngeal nerve, which can cause voice hoarseness
  • Presence of air in the space between the pleural space (which covers the lungs), which can then cause the lungs to collapse
  • Subcutaneous emphysema, or air trapped under the skin
  • Perforation of the oesophagus and trachea


  • Chernecky CC, Berger BJ (2013). Laboratory Tests and Diagnostic Procedures, 6th ed. St. Louis: Saunders.

  • Fischbach F, Dunning MB III (2015). A Manual of Laboratory and Diagnostic Tests, 9th ed. Philadelphia: Wolters Kluwer Health.
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