Cytogenetic analysis of pleural fluids has proved beneficial in difficult-to-diagnose cases. This process involves analyzing the chromosomes of cells in an effort to determine rearrangements or deletions that characterize certain tumors. We have also found cytogenetic analysis useful to differentiate carcinomas from the epithelial subtype of mesothelioma. These studies may increase diagnostic sensitivity to close to 90%. The assay, however, is not universally available and takes 5 to 7 days to complete. canadian-familypharmacy.com
Despite all currently available fluid analyses, the etiology of a small percentage of effusions remains unknown. Thoracoscopy or pleuroscopy is then indicated to establish a definitive diagnosis. Over a 3-year period, we used this minimally invasive technique to evaluate and treat 196 patients with symptomatic pleural processes. A definitive etiology was confirmed for each case (though some were known preoperatively). Half of these cases involved malignancy.
Many therapies have been proposed for the immediate treatment and long-term palliation of MPE. Thoracentesis alone is effective in relieving symptoms acutely. The mean time to fluid reaccumulation is as short as 4 days, with a 98% recurrence rate at 30 days. The sudden removal of more than 1.5 L may also result in reexpansion edema. Staged or more controlled drainage is recommended for very large effusions.
Representative data, pooled from a large number of reports using different methods to control MPE, were summarized by Hausheer and Yarbro in 1985. Table 2 compares these results with those obtained using newer sclerosing agents. Response was defined as no fluid reaccumulation at 1 month. These data represent singlemodality attempts at palliation.
Given the consistent 70 to 95% response rates achieved with these various agents to sclerose the pleural space, achieve visceroparietal pleural symphysis, and thus prevent recurrent MPE, the remaining question centers on which agent to use. Few comparative trials, and even fewer prospective comparative trials, have been published. In addition, tetracycline is no longer available in the United States. Doxycycline has been efficacious in European trials, but has not been studied in randomized comparative trials (to our knowledge). Two small randomized studies have shown talc to be superior to tetracycline (33 patients) and bleomycin (25 patients). In the talc vs tetracycline trial, the talc group achieved durable sclerosis in 92% of cases vs only 48% for tetracycline. In the study of bleomycin vs insufflated talc, the investigators reported 100% effusion control with talc with only 66% controlled with intracavitaiy bleomycin. In both of these small trials, patients failing to respond to tetracycline or bleomycin treatment underwent salvage therapy with talc poudrage. In an interesting retrospective, three-arm, comparative trial, Hartman et al looked at long-term control of MPE using talc insufflation, intrapleural tetracycline, or intrapleural bleomycin. At 3 months’ postsclerosis, talc had achieved a 95% success rate compared with 70% for bleomycin and only 47% for tetracycline.
Table 2—Efficacy of Various Single-Modality Methods to Palliate MPEs
|Approach||No. of Patients||Mean 30-d Control Rate, % (Range)|
|Talc (any route)||216||95|