thoracentesis /thôr′əsentē″sis/ [Gk, thorax + centesis, puncture] , the surgical perforation of the chest wall and pleural space with a needle to aspirate fluid for diagnostic or therapeutic purposes or to remove a specimen for biopsy. The procedure is usually performed using local anesthesia, with the patient in an upright position. Thoracentesis may be used to aspirate fluid to treat pleural effusion or to collect fluid samples for culture or examination. Also called thoracocentesis.
