Home > Encyclopedia of Nursing & Allied Health > Mediastinoscopy

Definition

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 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

This procedure allows direct visualization of the tissues and organs in the chest cavity behind the sternum (breastbone) and is used to detect or evaluate infections and various types of cancers. Originally the aim of mediastinoscopy was to retrieve tissue samples for microscopic analysis. Other indications for the procedure are diagnosing pulmonary lesions and predicting the benefit of surgery. Mediastinoscopy is often the diagnostic method of choice for detecting lymphoma, including Hodgkin's disease. Diagnosis of sarcoidosis (a chronic lung disease) and the staging of lung cancer can also be accomplished through mediastinoscopy. The lymph nodes in the mediastinum are likely to show if lung cancer has spread beyond the lungs (metastatis). Mediastinoscopy allows a physician to observe and extract a sample from the nodes for further study. Involvement of these lymph nodes can indicate the diagnosis and staging of lung cancer.

Alternatives to mediastinoscopy, such as computed tomography (CT), magnetic resonance imaging (MRI), and new developments in ultrasonography, have resulted in a decrease in the number of mediastinoscopies performed. In addition, fine-needle aspiration and core-needle biopsy procedures coupled with new techniques in thoracoscopy have brought alternative possibilities in examining mediastinal masses. As of 2000, the choice of procedures is one of the most controversial issues in the staging of lung cancer.

Precautions

Since 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.

Mediastinoscopy is contraindicated in those patients who have a superior vena cava obstruction, due to the risk of hemorrhage. The procedure is also contraindicated for patients with a tracheotomy.

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. 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, which allows the surgeon to see inside the area. The surgeon can insert tools through the hollow tube to help perform the exam. A sample of tissue from the lymph nodes or one of the organs 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 that 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 thorough and cost-effective diagnostic tool with less risk than some other procedures. Mediastinoscopy has been shown to be an effective and safe technique for biopsy of mediastinal masses in the pediatric population.

Preparation

Patients should sign a consent form after having reviewed the risks of mediastinoscopy and known risks or reactions to anesthesia. The patient should have nothing to eat or drink after midnight the day of the procedure, or at least 8 hours before the exam. A local anesthetic may be applied to the throat to ease discomfort during placement of the endotracheal tube.

Aftercare

Following mediastinoscopy, patients will be carefully monitored 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 and temporary chest pain, soreness, or tenderness at the site of incision.

Complications

Complications from the actual mediastinoscopy procedure are relatively rare. Risks to internal organs consist of puncture of the esophagus, trachea, or the blood vessels in the area. Air leaks from the lung can also occur and occasionally require additional treatment. Infection and hemorrhage are other rare complications. The usual risks associated with general anesthesia apply to this procedure. General anesthesia is safe for most patients, but it is estimated to cause major or minor complications in 3–10% of those having surgery of all types.

Results

In the majority of procedures performed to diagnose cancer, a normal result would involve evidence of normal lymph nodes and no tumors. In the case of lung cancer staging, results are related to the severity and progression of the cancer.

If the lymph nodes are malignant, this indicates that a cancer such as lymphoma (including Hodgkin's disease), lung cancer, or esophageal cancer are present.

Health care team roles

Either a surgeon or a trained pulmonary specialist performs this procedure. An anesthesiologist will obtain a medical history and supervise the anesthesia for the procedure. A Certified Registered Nurse Anesthetist (CRNA) may work under the direction of the anesthesiologist. Operating room personnel include the scrub person and a circulator. Depending on the facility, there may be unlicensed assistive personnel (UAPs) in attendance, as well.

Patient education

After the procedure, the patient will experience some pain and soreness at the incision site, and possibly a sore throat from the endotracheal tube. Pain at the incision site may last for up to two weeks after the procedure. Patients should be instructed that there will be a small scar wherever the instruments were inserted. There will be a small dressing over the incision. The incision site must be kept clean and dry for 48 hours, and then patients may shower.

Patients should notify their health care provider if they develop any of these symptoms:

• redness at the incision site
• drainage of blood or pus from the incision site
• fever more than 101°F (38.3 °C)
• progressive swelling at the incision site

---

KEY TERMS

---

Endotracheal—Within the trachea, which is commonly known as the windpipe.

Hodgkin's disease—A malignant disorder of lymph tissue (lymphoma) that appears to originate in a particular lymph node and later spreads to the spleen, liver, and bone marrow.

Mediastinum—The mass of organs and tissues separating the lungs. It contains the heart and large vessels, trachea, esophagus, thymus, lymph nodes, and connective tissue.

Sarcoidosis—A chronic disease known for development of nodules in the lungs, skin, lymph nodes, and bones.

Superior vena cava—The principal vein that drains the upper portion of the body.

Tracheotomy—Incision of the trachea through the skin and muscles of the neck.

---

Maggie Boleyn, RN, BSN