What happens to the pleural space affected by malignant effusion after bedside pleurodesis?

Background and objectivesEvaluate radiological characteristics of postpleurodesis pleural space of patients with recurrent malignant pleural effusion(RMPE). MethodsProspective cohort study including patients with RPME treated with bedside pleurodesis. We used CT scans to calculate pleural cavity volume immediately before pleurodesis(iCT) and 30 days after(CT30). Radiological evolution was calculated by the difference between pleural volumes on CT30 and iCT(volume). We categorized initial pleural volume as small(<500mL) or large space(500mL) and volume as positive(>254.49mL), unchanged(-268.77-254.49mL), or negative(<-268.77mL). Futhermore, we analyzed clinical effectiveness, pleural elastance, and adverse events. ResultsA total of 87 patients were analyzed. Pleural volume varied from 35-2750mL in iCT and from 0-2995mL in CT30(P=0.753). A total of 54 patients had initial small pleural space(62.06%) and 33 large(37.93%). Clinical failure occurred in 7.4% of small space group and in 24.6% of large(P=0.051, OR4.0(CI:1.098-14.570)). In small space group, 27.77% evolved with positive, 66.66% with unchanged and 5.55% with negative volume. In the large space group these numbers were respectively 21.21%, 27.27%, and 51.51%. ConclusionsThere is significant variability on pleural space volume. However, pleural volume remains unchanged in many cases. Besides that, more than half patients with initial large space coursed with relevant reduction. Finally, patients with initial small space presented a greater chance of clinical success.