[The role of thoracoscopy in pleural biopsy in cases with pleural effusion]

Between April 1985 and July 1989, 125 cases with pleural effusion were admitted to our department. The causes of pleural effusion were carcinomatous pleurisy in 47 cases, infection without tuberculosis in 34 cases, tuberculous pleurisy in 17 cases, cardiac insufficiency and hypoproteinemia in 11 cases, trauma and pneumothorax in nine cases, collagen disease in two cases and unknown origin in five cases. Carcinomatous pleurisy and tuberculous pleurisy, the differential diagnosis of which is very important, comprised 37% and 14% of all cases, respectively. These diseases can be definitively diagnosed by pleural biopsy, effusion cytology and/or effusion culture. In July 1987, we introduced thoracoscopy to improve the ratio of definitive diagnoses. The ratio for carcinomatous pleurisy in the previous term, when thoracoscopy was not being used, was 59%, while that in the latter term, when it was used, was 73%. The ratio for all cases with tuberculous pleurisy was 47%. Prior to June 1987, pleural biopsies in our department were performed with a Cope needle. Using that procedure, a low positive ratio of 50% was obtained. For thoracoscopic pleural biopsies, a high positive ratio of 84% was achieved (in carcinomatous pleurisy, 13 out of 15 cases; in tuberculous pleurisy, three out of four cases). This procedure was performed with minimal patient discomfort and no serious complications. Therefore, thoracoscopic pleural biopsy is recommended as a diagnostic procedure for cases with pleural effusion.