| 释义 |
pleural biopsy Pleural Biopsy DefinitionThe pleura is the membrane that lines the lungs and chest cavity. A pleural biopsy is the removal of pleural tissue for examination.PurposePleural biopsy is done to differentiate between benign and malignant disease, to diagnose viral, fungal, or parasitic diseases, and to identify a condition called collagen vascular disease of the pleura. It is also ordered when a chest x ray indicates a pleural-based tumor, reaction, or thickening of the lining.PrecautionsBecause pleural biopsy is an invasive procedure, it is not recommended for patients with severe bleeding disorders.DescriptionPleural biopsy is usually ordered when pleural fluid obtained by another procedure called thoracentesis (aspiration of pleural fluid) suggests infection, signs of cancer, or tuberculosis. Pleural biopsies are 85-90% accurate in diagnosing these diseases.The procedure most often performed for pleural biopsy is called a percutaneous (passage through the skin by needle puncture) needle biopsy. The procedure takes 30-45 minutes, although the biopsy needle itself remains in the pleura for less than one minute. This type of biopsy is usually performed by a physician at bedside, if the patient is hospitalized, or in the doctor's office under local anesthetic.The actual procedure begins with the patient in a sitting position, shoulders and arms elevated and supported. The skin overlying the biopsy site is anesthetized and a small incision is made to allow insertion of the biopsy needle. This needle is inserted with a cannula (a plastic or metal tube) until fluid is removed. Then the inner needle is removed and a trocar (an instrument for withdrawing fluid from a cavity) is inserted to obtain the actual biopsy specimen. As many as three separate specimens are taken from different sites during the procedure. These specimens are then placed into a fixative solution and sent to the laboratory for tissue (histologic) examination.PreparationPreparations for this procedure vary, depending on the type of procedure requested. Pleural biopsy can be performed in several ways: percutaneous needle biopsy (described above), by thoracoscopy (insertion of a visual device called a laparoscope into the pleural space for inspection), or by open pleural biopsy, which requires general anesthesia.AftercarePotential complications of this procedure include bleeding or injury to the lung, or a condition called pneumothorax, in which air enters the pleural cavity (the space between the two layers of pleura lining the lungs and the chest wall). Because of these possibilities, the patient is to report any shortness of breath, and to note any signs of bleeding, decreased blood pressure, or increased pulse rate.RisksRisks for this procedure include respiratory distress on the side of the biopsy, as well as bleeding, possible shoulder pain, pneumothorax (immediate) or pneumonia (delayed).Normal resultsNormal findings indicate no evidence of any pathologic or disease conditions.Abnormal resultsAbnormal findings include tumors called neoplasms (any new or abnormal growth) that can be either benign or malignant. Pleural tumors are divided into two classifications: primary (mesothelioma), or metastatic (arising from cancer sites elsewhere in the body). These tumors are often associated with an accumulation of fluid between the pleural layers called a pleural effusion, which itself may be caused by pneumonia, heart failure, cancer, or blood clot in the lungs (pulmonary embolism).Other causes of abnormal findings include viral, fungal, or parasitic infections, and tuberculosis.ResourcesBooksPagana, Kathleen Deska. Mosby's Manual of Diagnostic and Laboratory Tests. St. Louis: Mosby, Inc., 1998.pleural biopsy A 'blind' percutaneous biopsy of the pleura, often performed in tandem with thoracentesis to determine the cause of pleural effusions, which may be due to bacterial or TB infection or malignancy–eg, adenocarcinomas and mesotheliomas Contraindications Low platelet count, especially < 20,000/mm3, and low fluid volume |