Clinical Factors Influencing Spontaneous Pleurodesis Success in Malignant Pleural Effusion in Patients With Indwelling Pleural Catheter.

Background Indwelling pleural catheters (IPCs) provide effective palliation for malignant pleural effusion (MPE) and may induce spontaneous pleurodesis (SP). However, risk factors causing transudative effusion, such as hypoalbuminemia, congestive cardiac failure (CCF), and renal failure (RF), may reduce pleurodesis success. Evidence on the impact of these comorbidities in MPE patients undergoing IPC placement remains limited. Objective To evaluate the impact of hypoalbuminemia, CCF and RF on successful SP in MPE. Methods A retrospective single-centre study was conducted in a tertiary care hospital on all patients with cytologically or radiologically confirmed MPE who underwent IPC placement between January 2020 and December 2024. SP was defined as catheter removal and no fluid recurrence up to 90 days. Demographic data, albumin levels, comorbidities, cancer type, and active anti-cancer therapy were compared between the SP and non-pleurodesis (NP) group. Results Among 110 patients (mean age 70 years; 54/110, 49% male), SP occurred in 30/110 (27%). Mean serum albumin was higher in the SP group (25.2 vs 20.4 g/L, p=0.001). CCF was present in 3/30 (10%) SP group compared with 15/80 (19%) NP group (p=0.005), while RF occurred only in the NP group, 4/80 (5%). Systemic anti-cancer therapy was associated with higher SP rates (26/30, 87% vs 32/80, 40%; p<0.001). SP varied by cancer type, highest in mesothelioma (6/12, 50%) and absent in small cell lung cancer (0/3, 0%). Conclusions Higher albumin, active anti-cancer therapy, and absence of multiple comorbidities causing transudative effusion predict successful SP. Identifying these factors may improve patient selection and procedural outcomes.