Pleural Effusion after Hepatic Radiofrequency Ablation with Artificial Ascites: Clinical Spectrum and Significance

To retrospectively investigate incidence, clinical outcome, and risk factors of iatrogenic pleural effusion in patients with hepatic tumors undergoing radiofrequency (RF) ablation using artificial ascites (AA).Patients (N = 163) who underwent RF ablation using AA were classified into pleural effusion and non-pleural effusion groups according to the presence of pleural effusion on immediate follow-up CT and chest radiograph after RF ablation. The pleural effusion group included asymptomatic and symptomatic subgroups. The incidence and subsequent clinical outcomes of patients developing pleural effusion after RF ablation were evaluated.Overall, 96 patients (58.9%) developed pleural effusion, which resolved in 4.4 d ± 3.1. Hospital length of stay in the pleural effusion group was longer than the non-pleural effusion group (6.5 d ± 2.6 vs 5.7 d ± 2.8, P.01). The pleural effusion group had longer AA infusion time (P = .01), larger infused AA volume (P.01), and longer ablation time (P.01) than the non-pleural effusion group. Eighteen patients (18.8%) developed symptomatic pleural effusion and had a larger infused AA volume than asymptomatic patients with pleural effusion (P.01). Pleural effusion duration and hospital length stay were also longer in the symptomatic pleural effusion subgroup than in the asymptomatic subgroup (P.01). Infused AA volume was the only independent prognostic factor of pleural effusion duration in multivariate analysis (P = .038).Pleural effusion frequently occurs after RF ablation using AA. Although generally considered negligible, pleural effusion could be a clinical problem and prolong hospitalization. Therefore, operators should be careful not to infuse too much AA when performing RF ablation.