Lung Biopsy (Encyclopedia of Nursing & Allied Health)

Definition

Lung biopsy is a procedure by which a small sample of lung tissue is obtained for examination. Usually, it is examined under the microscope and also may be sent to the microbiological laboratory for culture. Microscopic examination is performed by pathologists.

Purpose

A lung biopsy is usually ordered to determine the cause of abnormalities that appear on chest x rays, such as nodules or infiltrates. Lung biopsies are performed to confirm a diagnosis of cancer, especially if malignant cells are detected in the patient's sputum or bronchial washing. In addition to evaluating lung tumors and their associated symptoms, lung biopsies may be used in the diagnosis of lung infections, especially tuberculosis and Pneumocystis pneumonia, drug reactions, and chronic diseases of the lung such as sarcoidosis.

A lung biopsy can be used for treatment as well as diagnosis. Bronchoscopy, a type of lung biopsy performed with a long slender instrument called a bronchoscope, can be used to clear a patient's air passages of secretions and to remove blockages from the airways. Today, flexible fiberoptic bronchoscopes, which are easier to use than rigid scopes, are used to perform most biopsies.

Precautions

As with any other biopsy, lung biopsies should not be performed on patients who have a tendency to bleed or abnormal blood clotting because of low platelet counts or prolonged prothrombin time (PT) or partial thromboplastin time (PTT). Platelets are small blood cells that play a role in the blood clotting process. PT and PTT measure how well blood clots. If they are prolonged, it might be unsafe to perform a biopsy because of the risk of bleeding. If the platelet count is lower than 50,000/cubic mm, the patient may be given a platelet transfusion as a temporary relief measure, and a biopsy can then be performed.

Description

Overview

The mediastinum separates the right and the left lungs from each other. The heart, the trachea, the lymph nodes, and the esophagus lie in the mediastinum. Lung biopsies may involve mediastinoscopy, as well as the lungs themselves.

Types of lung biopsies

Lung biopsies can be performed using a variety of techniques. A bronchoscopy is ordered if a lesion identified on the x ray seems to be located in the periphery of the chest. If the suspicious area lies close to the chest wall, a needle biopsy can be done. If both these methods fail to diagnose the problem, an open lung biopsy may be performed. When there is a question about whether the lung cancer has spread to the lymph nodes in the mediastinum, a mediastinoscopy is performed.

NEEDLE BIOPSY. About an hour before the needle biopsy procedure, a sedative is administered to the patient. The patient is mildly sedated but fully awake. An X ray technician takes a computerized axial tomography (CT) scan to identify the location of the suspicious areas. Markers are placed on the overlying skin to mark the biopsy site. The skin is thoroughly cleansed with an antiseptic solution, and a local anesthetic is injected to numb the area.

The physician then makes a small incision, about half an inch (1.25 cm) in length. The patient is asked to take a deep breath and hold it while the physician inserts the biopsy needle through the incision into the lung. When enough tissue has been obtained, the needle is withdrawn. Pressure is applied at the biopsy site and a sterile bandage is placed over the cut. The entire procedure takes between 30 and 45 minutes.

The patient may feel a brief sharp pain or some pressure as the biopsy needle is inserted. Most do not experience severe pain.

OPEN BIOPSY. Open biopsies are performed in a hospital operating room under general anesthesia. As with needle biopsies, patients are sedated before the procedure. An intravenous line is placed to give medications or fluids as necessary. A hollow tube, called an endotracheal tube, is passed through the mouth, into the airway leading to the lungs. It is used to convey the general anesthetic.

Once the patient is anesthetized, the surgeon makes an incision over the lung area, a procedure called a thoracotomy. Some lung tissue is removed and the incision is closed with sutures. The entire procedure usually takes about an hour. A chest tube is sometimes placed with one end inside the lung and the other end protruding through the closed incision. Chest tube placement is done to prevent the lungs from collapsing by removing the air from the lungs. The tube is removed a few days after the biopsy.

A chest x ray is done following an open biopsy, to check for a pneumothorax (lung collapse). The patient may experience some grogginess for a few hours after the procedure. Patients also may experience tiredness and muscle aches for a day or two, because of the general anesthesia. The throat may be sore because of the placement of the endotracheal tube. The patient may also have some pain or discomfort at the incision site, which can be relieved by pain medication.

VIDEO-ASSISTED THORASCOPIC SURGERY. A new technique, video-assisted thorascopic surgery (VATS), also can be used to biopsy lung and mediastinal lesions. VATS may be performed on selected patients in place of open lung biopsy. To perform a VATS procedure, the surgeon makes several small incisions in the patient's chest wall. A thorascope, a thin, hollow, lighted tube with a tiny video camera mounted on it, is inserted through one of the small incisions. The other incisions allow the surgeon to insert surgical instruments to retrieve tissue for biopsy.

MEDIASTINOSCOPY. The preparation for a mediastinoscopy is similar to that for an open biopsy. The patient is sedated and prepared for general anesthesia. The neck and the chest are cleansed with an antiseptic solution.

After the patient is anesthetized, an incision about two or three inches long is made at the base of the neck. A thin, hollow, lighted tube, called a mediastinoscope, is inserted through the incision into the space between the right and the left lungs. The surgeon removes any lymph nodes or tissues that look abnormal. The mediastinoscope is then removed, and the incision is sutured and bandaged. A mediastinoscopy takes about an hour.

Preparation

Before scheduling a lung biopsy, the physician performs a preoperative history and physical examination. An electrocardiogram (EKG) and laboratory tests may be performed before the procedure to check for clotting problems, anemia, and blood type, in case a transfusion becomes necessary.

Patient education

Patients who will undergo surgical diagnostic and treatment procedures should be encouraged to stop smoking. Patients able to stop smoking several weeks before surgical procedures have fewer postoperative complications.

Before any procedure is performed, the patient is asked to sign a consent form. The nurse may review the procedure and answer questions about the consent form or procedure. The nurse will advise the patient preparing for general anesthesia to refrain from eating or drinking anything for at least 12 hours before the biopsy.

Aftercare

Needle biopsy

Following a needle biopsy, the patient is allowed to rest comfortably. The nurse checks the patient's status at two-hour intervals. If there are no complications after four hours, then the patient can go home.

Patient education

Prior to discharge to home, the nurse instructs the patient about resuming normal activities. Patients are advised to rest at home for a day or two before resuming regular activities, and to avoid strenuous activities for a week after the biopsy.

Open biopsy, VATS, or mediastinoscopy

After an open biopsy, VATS, or mediastinoscopy, patients are taken to the recovery room for observation. If no complications develop, they are returned to the hospital room. Nursing care includes monitoring temperature, pulse blood pressure and respiration. Fever may indicate infection, and decreased breath sounds may be symptoms of pneumothorax. Sutures are usually removed after seven to 14 days.

If the patient has extreme pain, light-headedness, or difficulty breathing after an open biopsy, the physician should be notified immediately. The sputum may be slightly bloody for a day or two after the procedure. Heavy or persistent bleeding requires evaluation by the physician.

Complications

Needle biopsy

Needle biopsy is associated with fewer risks than open biopsy, because it does not involve general anesthesia. Rarely, the lung may collapse because of air that leaks in through the hole made by the biopsy needle. If a pneumothorax (lung collapse) occurs, a chest tube is inserted into the pleural cavity to re-expand the lung. Some hemoptysis (coughing up of blood) occurs in 5% of needle biopsies. Prolonged bleeding or infection may also occur, although these are very rare.

Open biopsy

Possible complications of an open biopsy include infection or pneumothorax. Death occurs in about 1 in 3000 cases. If the patient has very severe breathing problems before the biopsy, then breathing may be further impaired following the operation. For patients with normal lung function before the biopsy, the risk of respiratory problems resulting from or following the procedure is very small.

Mediastinoscopy

Complications due to mediastinoscopy are rare; death occurs in fewer than one in 3000 cases. More common complications include pneumothorax or bleeding caused by damage to the blood vessels near the heart. Mediastinitis, infection of the mediastinum, may develop. Injury to the esophagus or larynx may occur. If the nerves leading to the larynx are injured, the patient may be left with a permanently hoarse voice. All of these complications are rare.

Results

Abnormal results of needle biopsy, VATS, and open biopsy may be associated with diseases other than cancer. Nodular lesions, while frequently cancerous, can also be the result of active infections such as tuberculosis, or may be healed scars from a previous infection. In a third of biopsies using a mediastinoscope, the lymph nodes that are biopsied prove to be cancerous. Abnormal results should always be considered in the context of the patient's medical history, physical examination, and other tests such as sputum examination, chest x rays, etc. before a definitive diagnosis is made.

Health care team roles

Fiberoptic bronchoscopy is performed by pulmonologists, physician specialists in pulmonary medicine. CT guided needle biopsy is done by interventional radiologists, physician specialists in radiological procedures. Thoracic surgeons perform open biopsy and VATS. Specially trained nurses, x ray, and laboratory technicians assist during the procedures and provide pre and postoperative education and supportive care.

KEY TERMS

Bronchoscopy medical test that enables the physician to see the breathing passages and the lungs through a hollow, lighted tube.

Endotracheal tube hollow tube that is inserted into the windpipe to administer anesthesia.

Lymph nodesmall, bean-shaped structures scattered along the lymphatic vessels which serve as filters. Lymph nodes trap bacteria or cancer cells that are traveling through the lymphatic system.

Mediastinoscopy procedure that allows the physician to see the organs in the mediastinal space using a thin, lighted, hollow tube (a mediastinoscope).

Mediastinumhe area between the lungs, bounded by the spine, breastbone, and diaphragm.

Pneumothorax condition in which air or gas enters the pleura (area around the lungs) and causes a collapse of the lung.

Sputum mucus-rich secretion that is coughed up from the passageways (bronchial tubes) and the lungs.

Barbara Wexler