Mediastinoscopy is a surgical procedure that allows physicians to view areas of the mediastinum, the cavity behind the breastbone that lies between the lungs. The organs in the mediastinum include the heart and its vessels, the lymph nodes, trachea, esophagus, and thymus.
Mediastinoscopy is most commonly used to detect or stage cancer. It is also ordered to detect infection, and to confirm diagnosis of certain conditions and diseases of the respiratory organs. The procedure involves insertion of an endotracheal (within the trachea) tube, followed by a small incision in the chest. A mediastinoscope is inserted through the incision. The purpose of this equipment is to allow the physician to directly see the organs inside the mediastinum, and to collect tissue samples for laboratory study.
Description
Mediastinoscopy is usually performed in a hospital under general anesthesia. An endotracheal tube is inserted first, after local anesthesia is applied to the throat. Once the patient is under general anesthesia, a small incision is made usually just below the neck or at the notch at the top of the breastbone. The surgeon may clear a path and feel the patient's lymph nodes first to evaluate any abnormalities within the nodes. Next, the physician will insert the mediastinoscope through the incision. The scope is a narrow, hollow tube with an attached light that allows the surgeon to see inside the area. The surgeon can insert tools through the hollow tube to help perform biopsies. A sample of tissue from the lymph nodes or a mass can be extracted and sent for study under a microscope or on to a laboratory for further testing.
In some cases, analysis of the tissue sample which shows malignancy will suggest the need for immediate surgery while the patient is already prepared and under anesthesia. In other cases, the surgeon will complete the visual study and tissue extraction and stitch the small incision closed. The patient will remain in the surgery recovery area until it is determined that the effects of anesthesia have lessened and it is safe for the patient to leave the area. The entire procedure should take about an hour, not counting preparation and recovery time. Studies have shown that mediastinoscopy is a safe, thorough, and cost-effective diagnostic tool with less risk than some other procedures.
Who Performs the Procedure and Where Is It Performed?
A mediastinoscopy procedure is usually performed by a thoracic or general surgeon in a hospital setting.
Questions to Ask the Doctor
Why is this test needed?
Is the test dangerous?
What test preparation is required?
How long will the test take?
When will the results be available?
What form of anesthesia will be used?
Is the surgeon board certified?
How many mediastinoscopy procedures has the surgeon performed?
What is the surgeon's complication rate?
Definition
Mediastinoscopy is a surgical procedure that allows physicians to view areas of the mediastinum, the cavity behind the sternum (breastbone) that lies between the lungs. The organs in the mediastinum include the heart and its vessels, the lymph nodes, trachea, esophagus, and thymus.
Mediastinoscopy is most commonly used to detect or stage cancer. It is also ordered to detect infection, and to confirm diagnosis of certain conditions and diseases of the respiratory organs. The procedure involves insertion of an endotracheal (within the trachea) tube, followed by a small incision in the chest. A mediastinoscope is inserted through the incision. The purpose of this equipment is to allow the physician to directly see the organs inside the mediastinum, and to collect tissue samples for laboratory study.
Purpose
Mediastinoscopy is often the diagnostic method of choice for detecting lymphoma, including Hodgkin's disease. The diagnosis of sarcoidosis (a chronic lung disease) and the staging of lung cancer can also be accomplished through mediastinoscopy. Lung cancer staging involves a determination of the level or progression of the cancer into stages. These stages help a physician study cancer and provide consistent cancer definition levels and corresponding treatments. They also provide some guidance as to prognosis. The lymph nodes in the mediastinum are likely to reveal if lung cancer has spread beyond the lungs. Mediastinoscopy allows a physician to observe and extract a sample from the nodes for further study. Involvement of these lymph nodes indicates the diagnosis and stage of lung cancer.
Mediastinoscopy may also be ordered to verify a diagnosis that was not clearly confirmed by other methods, such as certain radiographic and laboratory studies. Mediastinoscopy may aid in some surgical biopsies of nodes or cancerous tissue in the mediastinum. In fact, a surgeon may immediately perform a surgical procedure if a malignant tumor is confirmed while the patient is undergoing mediastinoscopy. In these cases, the diagnostic exam and surgical procedure are combined into one operation.
Mediastinoscopy provides a diagnosis in 10–75% of cases, depending on histology, location, and size of cancer. The false positive rate, however can be as high as 20%.
Demographics
Approximately 130,000 new pulmonary nodules are diagnosed each year in the United States. Of those, half are malignant. The majority of pulmonary nodules are diagnosed via mediastinoscopy.
Description
Mediastinoscopy is usually performed in a hospital under general anesthesia. Before the general anesthesia is administered, local anesthesia is applied to the throat while an endotracheal tube is inserted. Once the patient is under general anesthesia, a small incision is made, usually just below the neck or at the notch at the top of the sternum. The surgeon may clear a path and feel the person's lymph nodes first to evaluate any abnormalities within the nodes. Next, the physician inserts the mediastinoscope through the incision. The scope is a narrow, hollow tube with an attached light that allows the surgeon to see inside the area. The surgeon can insert tools through the hollow tube to help perform biopsies. A tissue sample from the lymph nodes or a mass can be removed and sent for study under a microscope, or to a laboratory for further testing.
In some cases, tissue sample analysis that shows malignancy will suggest the need for immediate surgery while the person is already prepared and under anesthesia. In other cases, the surgeon will complete the visual study and tissue removal, and stitch the small incision closed. The person will remain in the surgerical recovery area until the effects of anesthesia have lessened and it is safe to leave the area. The entire procedure should require about an hour, not counting preparation and recovery time. Studies have shown that mediastinoscopy is a safe, thorough, and cost-effective diagnostic tool with less risk than some other procedures.
Diagnosis/Preparation
Because mediastinoscopy is a surgical procedure, it should only be performed when the benefits of the exam's findings outweigh the risks of surgery and anesthesia. Individuals who previously had mediastinoscopy should not receive it again if there is scarring from the first exam.
Several other medical conditions, such as impaired cerebral circulation, obstruction or distortion of the upper airway, or thoracic aortic aneurysm (abnormal dilation of the thoracic aorta) may also preclude mediastinoscopy. Certain structures in a person's anatomy that can be compressed by the mediastinoscope may complicate these pre-existing medical conditions.
Patients are asked to sign a consent form after reviewing the risks of mediastinoscopy and known risks and reactions to anesthesia. The physician will normally instruct the patient to fast from midnight before the test until after the procedure is completed. A physician may also prescribe a sedative the night before the exam and again before the procedure. Often a local anesthetic will be applied to the throat to prevent discomfort during placement of the endotracheal tube.
Aftercare
Following mediastinoscopy, patients will be carefully monitored and watched for changes in vital signs, or symptoms of complications from the procedure or anesthesia. The patient may have a sore throat from the endotracheal tube, experience temporary chest pain, and have soreness or tenderness at the incision site.
Risks
Complications from the actual mediastinoscopy procedure are relatively rare. The overall complication rates in various studies have been reported in the range of 1.3–3%. However, the following complications, in decreasing order of frequency, have been reported:
transient hemiparesis (paralysis on one side of the body)
The usual risks associated with general anesthesia also apply to this procedure.
Normal Results
In the majority of procedures performed to diagnose cancer, a normal result indicates the presence of small, smooth lymph nodes, and no abnormal tissue, growths, or signs of infection. In the case of lung cancer staging, results are related to the severity and progression of the cancer.
Morbidity and Mortality Rates
Abnormal findings may indicate lung cancer, tuberculosis, the spread of disease from one body part to another, sarcoidosis (a disease that causes nodules, usually affecting the lungs), lymphoma (abnormalities in the lymph tissues), and Hodgkin's disease.
Complications of mediastinoscopy include bleeding, pain, and post-procedure infection. These are relatively uncommon. Mortality is extremely rare.
Alternatives
A less invasive technique is ultrasound. However, it is not as specific as mediastinoscopy, and the information obtained is not as useful in making a diagnosis.
Although still performed, there is a decline in the use of mediastinoscopy as a result of advancements in computed tomography (CT), magnetic resonance imaging (MRI), and ultrosonography techniques. In addition, improved fine-needle aspiration (withdrawing fluid using suction) results of and core-needle biopsy (using a needle to obtain a small tissue sample) investigations, along with new techniques in thoracoscopy (examination of the thoracic cavity with a lighted instrument called a thoracoscope) offer additional options in examining masses in the mediastinum. Mediastinoscopy may be required when other methods cannot be used or when they provide inconclusive results.
Bland, K.I., W.G. Cioffi, M.G. Sarr, Practice of GeneralSurgery. Philadelphia: Saunders, 2001.
Fischbach, F. and F. Talaska A Manual of Laboratory and Diagnostic Tests 6th ed. Philadelphia: Lippincott Williams and Wilkins, 2000.
Grace, P.A., A. Cuschieri, D. Rowley, N. Borley, A. Darzi ClinicalSurgery 2nd Edition. London: Blackwell Publishing, 2003.
Schwartz, S.I., J.E. Fischer, F.C. Spencer, G.T. Shires, J.M. Daly, J.M. Principles of Surgery 7th edition. New York: McGraw Hill, 1998.
Townsend, C., K.L. Mattox, R.D. Beauchamp, B.M. Evers, D.C. Sabiston Sabiston's Review of Surgery 3rd Edition. Philadelphia: Saunders, 2001.
Periodicals
Beadsmoore C.J., N.J. Screaton. "Classification, Ttaging and Prognosis of Lung Cancer." European Journal of Radiology 45(1) (2003): 8–17.
Choi, Y.S., Y.M. Shim, J. Kim, K. Kim. "Mediastinoscopy in Patients with Clinical Ctage I Non-small Cell Lung Cancer." Annals of Thoracic Surgery 75(2) (2003): 364–6.
Detterbeck, F.C., M.M. DeCamp, Jr., L.J. Kohman, G.A. Silvestri. "Lung cancer. Invasive staging: the guidelines." Chest 123(1 Suppl) (2003): 167S–175S.
Falcone F., F. Fois, D. Grosso. "Endobronchial Ultrasound." Respiration 70(2) (2003): 179–94.
Sterman, D.H., E. Sztejman, E. Rodriguez, J. Friedberg. "Diagnosis and Staging of 'Other Bronchial Tumors'." Chest Surgery Clinics of North America 13(1) (2003): 79–94.
Organizations
American Board of Surgery. 1617 John F. Kennedy Boulevard, Suite 860, Philadelphia, PA 19103. (215) 568-4000, fax: 215-563-5718. http://www.absurgery.org.
American Cancer Society. 1599 Clifton Rd. NE, Atlanta, GA 30329. (800) 227-2345, http://www.cancer.org .
American College of Surgeons. 633 North St. Clair Street, Chicago, IL 60611-32311. (312) 202-5000, fax: (312) 202-5001. postmaster@facs.org. http://www.facs.org.
American Lung Association. 1740 Broadway, New York, NY 10019-4374. (800) 586-4872. http://www.lungusa.org.
American Medical Association. 515 N. State Street, Chicago, IL 60610. (312) 464-5000, http://www.ama-assn.org.
Society of Thoracic Surgeons. 633 N. Saint Clair St., Suite 2320, Chicago, IL 60611-3658. (312) 202-5800, fax: 312-202-5801. sts@sts.org. http://www.sts.org.
Mediastinoscopy is a surgical procedure that allows physicians to view areas of the mediastinum, the cavity behind the breastbone that lies between the lungs. The organs in the mediastinum include the heart and its vessels, the lymph nodes, trachea, esophagus, and thymus.
Mediastinoscopy is most commonly used to detect or stage cancer. It is also ordered to detect infection, and to confirm diagnosis of certain conditions and diseases of the respiratory organs. The procedure involves insertion of an endotracheal (within the trachea) tube, followed by a small incision in the chest. A mediastinoscope is inserted through the incision. The purpose of this equipment is to allow the physician to directly see the organs inside the mediastinum, and to collect tissue samples for laboratory study.
Purpose
Mediastinoscopy is often the diagnostic method of choice for detecting lymphoma, including Hodgkin's disease. The diagnosis of sarcoidosis (a chronic lung disease) and the staging of lung cancer can also be accomplished through mediastinoscopy. Lung cancer staging involves the placement of the cancer's progression into stages, or levels. These stages help a physician study cancer and provide consistent definition levels of cancer and corresponding treatments. The lymph nodes in the mediastinum are likely to show if lung cancer has spread beyond the lungs. Mediastinoscopy allows a physician to observe and extract a sample from the nodes for further study. Involvement of these lymph nodes indicates diagnosis and stages of lung cancer.
Mediastinoscopy may also be ordered to verify a diagnosis that was not clearly confirmed by other methods, such as certain radiographic and laboratory studies. Mediastinoscopy may also aid in certain surgical biopsies of nodes or cancerous tissue in the mediastinum. In fact, the surgeon may immediately perform a surgical procedure if a malignant tumor is confirmed while the patient is undergoing mediastinoscopy, thus combining the diagnostic exam and surgical procedure into one operation when possible.
Although still performed in 2001, advancements in computed tomography (CT) and magnetic resonance imaging (MRI) techniques, as well as the new developments in ultrasonography, have led to a decline in the use of mediastinoscopy. In addition, better results of fine-needle aspiration (drawing out fluid by suction) and core-needle biopsy (using a needle to obtain a small tissue sample) investigations, along with new techniques in thoracoscopy (examination of the thoracic cavity with a lighted instrument called a thoracoscope) offer additional options in examining mediastinal masses. Mediastinoscopy may be required, however, when these other methods cannot be used or when the results they provide are inconclusive.
Precautions
Because mediastinoscopy is a surgical procedure, it should only be performed when the benefits of the exam's findings outweigh the risks of surgery and anesthesia. Patients who previously had mediastinoscopy should not receive it again if there is scarring present from the first exam.
Several other medical conditions, such as impaired cerebral circulation, obstruction or distortion of the upper airway, or thoracic aortic aneurysm (abnormal dilation of the thoracic aorta) may also preclude mediastinoscopy. Anatomic structures that can be compressed by the mediastinoscope may complicate these pre-existing medical conditions.
Description
Mediastinoscopy is usually performed in a hospital under general anesthesia. An endotracheal tube is inserted first, after local anesthesia is applied to the throat. Once the patient is under general anesthesia, a small incision is made usually just below the neck or at the notch at the top of the breastbone. The surgeon may clear a path and feel the patient's lymph nodes first to evaluate any abnormalities within the nodes. Next, the physician will insert the mediastinoscope through the incision. The scope is a narrow, hollow tube with an attached light that allows the surgeon to see inside the area. The surgeon can insert tools through the hollow tube to help perform biopsies. A sample of tissue from the lymph nodes or a mass can be extracted and sent for study under a microscope or on to a laboratory for further testing.
In some cases, analysis of the tissue sample which shows malignancy will suggest the need for immediate surgery while the patient is already prepared and under anesthesia. In other cases, the surgeon will complete the visual study and tissue extraction and stitch the small incision closed. The patient will remain in the surgery recovery area until it is determined that the effects of anesthesia have lessened and it is safe for the patient to leave the area. The entire procedure should take about an hour, not counting preparation and recovery time. Studies have shown that mediastinoscopy is a safe, thorough, and cost-effective diagnostic tool with less risk than some other procedures.
Preparation
Patients are asked to sign a consent form after having reviewed the risks of mediastinoscopy and known risks or reactions to anesthesia. The physician will normally instruct the patient to fast from midnight before the test until after the procedure is completed. A physician may also prescribe a sedative the night before the exam and before the procedure. Often a local anesthetic will be applied to the throat to prevent discomfort during placement of the endotracheal tube.
Aftercare
Following mediastinoscopy, patients will be carefully monitored to watch for changes in vital signs or indications of complications of the procedure or the anesthesia. A patient may have a sore throat from the endotracheal tube, temporary chest pain, and soreness or tenderness at the site of incision.
Risks
Complications from the actual mediastinoscopy procedure are relatively rare—the overall complication rate in various studies has been 1.3–3.0%. However, the following complications, in decreasing order of frequency, have been reported:
transient hemiparesis (paralysis on one side of the body)
The usual risks associated with general anesthesia also apply to this procedure.
Normal Results
In the majority of procedures performed to diagnose cancer, a normal result involves evidence of small, smooth, normal-appearing lymph nodes and no abnormal tissue, growths, or signs of infection. In the case of lung cancer staging, results are related to the severity and progression of the cancer.
Questions to Ask the Doctor
Why do I need this test?
Is the test dangerous?
How do I prepare for the test?
How long will the test take?
Will I get general or local anesthesia?
How soon will I get my test results?
Abnormal Results
Abnormal findings may indicate lung cancer, tuberculosis, the spread of disease from one body part to another, sarcoidosis (a disease that causes nodules, usually affecting the lungs), lymphoma (abnormalities in the lymph tissues), and Hodgkin's disease.
Resources
Books
Fischbach, Frances Talaska. A Manual of Laboratory and Diagnostic Tests. 6th ed. Philadelphia: Lippincott Williams and Wilkins, 2000.
Periodicals
Deslauriers, Jean, and Jocelyn Gregoire. "Clinical and Surgical Staging of Non-Small Cell Lung Cancer." Chest, Supplement (April 2000): 96S–103S.
Tahara R. W., et al. "Is There a Role for Routine Mediastinoscopy in Patients With Peripheral T1 Lung Cancers?" American Journal of Surgery (December 2000): 488–491.
Organizations
Alliance for Lung Cancer Advocacy, Support, and Education. P.O. Box 849, Vancouver, WA 98666. 800–298–2436. .
American Cancer Society. 1599 Clifton Rd. NE, Atlanta, GA 30329. 800–ACS–2345 .
American Lung Association. 1740 Broadway, New York, NY 10019–4374. 800–LUNG–USA (800–586–4872). .
To examine the mediastinum (the space between the lungs) if imaging techniques suggest that it contains an abnormality but cannot determine its nature.
To diagnose sarcoidosis, cancers, tuberculosis, and other infections.
To determine to what extent the cancer has spread (staging of lung or other cancer).
How it works
Fiber-optic technology allows direct viewing of the area between the lungs as well as removal of a biopsy sample.
Preparation
Avoid eating or drinking for 12 hours before the test.
You will receive general anesthesia. A soft breathing tube is usually inserted through your windpipe (called endotracheal intubation) to make sure you breathe properly during the procedure.
Test procedure
A small incision is made through your skin and tissues, usually between the area of the collarbones.
A mediastinoscope, a long tube with a light source, is introduced into the area between the lungs.
The doctor examines the mediastinum through the viewing instrument and removes tissue samples (biopsy) from any suspicious areas.
After the test
After recovering from general anesthesia, an overnight hospital stay may be necessary. In many cases, however, the patient is discharged a few hours after the test. You should be able to return to regular activities within a few hours.
Factors affecting results
Accurate selection of the biopsy site.
Interpretation
The doctor observes the structures in the mediastinum. The biopsy sample removed during the procedure is examined under a microscope and provides additional information. A diagnosis may be suggested by the appearance of the mediastinum. Confirmation needs to be made pathologically. Biopsy material may also be sent for culture.
Advantages
The test allows the doctor to make definitive diagnosis of several disorders of the lung and chest.
Disadvantages
It's invasive.
It requires general anesthesia.
The next step
If a diagnosis is made by mediastinoscopy, decisions about treatment can be made.
If a diagnosis is not made, further evaluation may be necessary, perhaps with other surgical biopsies.
Mediastinoscopy is a surgical procedure that enables visualization of the contents of the mediastinum, usually for the purpose of obtaining a biopsy. Mediastinoscopy is often used for staging of lymph nodes of lung cancer or for diagnosing other conditions effecting structures in the mediastinum such as sarcoidosis or lymphoma.
Mediastinoscopy involves making an incision approximately 1 cm above the suprasternal notch of the sternum, or breast bone. Dissection is carried out down to the pretracheal space and down to the carina. A scope (mediastinoscope) is then advanced into the created tunnel which provides a view of the mediastinum. The scope may provide direct visualization or may be attached to a video monitor.
Mediastinoscopy provides access to mediastinal lymph node levels 2, 4, and 7.
Extended mediastinoscopy
Extended mediastinoscopy is a technique which allows access to the pre-aortic (level 6) and aortopulmonary window (level 5) lymph nodes.
Parasternal mediastinotomy
A left anterior parasternal mediastinotomy is also called the Chamberlain procedure. It involves an incision in the left third intercostal space, and allows access to levels 5 and 6 lymph node stations.
The Chamberlain procedure is a minimally invasive operation performed by a thoracic surgeon. A related procedure, known as the Jolly Procedure, is also an anterior mediastinotomy. An extended Chamberlain procedure is called an anterior thoracotomy.
The Chamberlain procedure is used to biopsy lymph nodes in the center of the chest, or to biopsy a mass in the center of the chest. The Chamberlain procedure differs from a cervical mediastinoscopy by the location of the incision, and the location of the lymph nodes or mass to be biopsied.
The Chamberlain procedure is used to biopsy lymph nodes or masses in the aorto-pulmonary window on the left side of the chest, or nodes in the hilar areas of the lung. (In contrast, the cervical mediastinoscopy procedure is used to biopsy nodes or masses to the front or side of the trachea, or windpipe.) The aorto-pulmonary window is the area in the center of the chest bound by the aorta superiorly, and the pulmonary artery inferiorly. This area contains lymph nodes that filter lymph coming from the left lung, especially the left upper lobe. If a lung cancer is present in the left lung, the Chamberlain procedure is useful for staging the cancer (determining the extent of spread.) The hilar areas of the lung (the hilum) are the areas of the lung where the pulmonary artery and vein (the blood supply) join the lung.
The Chamberlain procedure is usually done on the left side of the chest, because the aorto- pulmonary window is on the left side. However, the procedure is used for the right side under certain conditions.
The patient is placed under general anesthesia. The skin of the chest is prepped with a sterile solution. A small, two inch incision is made over the second rib where it joins the breast bone (at the Angle of Louis.) The incision is carried down through the pectoralis major muscle (the "pecs") by spreading the muscle fibers apart. The cartilage of the second rib is located (the costal cartilage) and is removed. The internal mammary artery and vein deep to the cartilage are sometimes tied and cut. The parietal pleura (the inside lining of the chest wall) is then dissected to the side, and the surgery is directed into the center of the chest, between the aorta and the pulmonary artery. Great care is taken not to injure the large blood vessels. Biopsies are taken of the respective abnormal lymph nodes or mass. The incision is then closed, without replacing the cartilage.
Occasionally, the nodes or mass cannot be safely located or biopsied by this technique. Under those circumstances, a decision is made by the surgeon to enlarge the incision slightly, open the parietal pleura, move the lung out of the way, and approach the nodes or mass from inside the pleural space. By opening the pleura and extending the incision, an anterior thoracotomy is created. Because air has been introduced into the area around the lung (the pleural space), a chest tube may be required to remain overnight to drain the air from the chest.
When the nodes or mass have been biopsied, the incision is closed with absorbable suture, and air is evacuated from the chest.
The risk of a Chamberlain procedure is very low. The chief risk is that of opening the pleura, and the requirement for placement of a chest tube (drain.) Although very rare, there is a risk of bleeding from a large blood vessel such as the aorta or pulmonary artery. Such bleeding would require a sternotomy or thoracotomy to stop the bleeding. Most patients go home the same day as surgery. Most return to work within a few days or a week, and will require pain pills for only a few days. The patient may shower 48 hours after surgery, and should not soak the incision under water in a bath tub or spa for three weeks.
