Pre-EDIT: A Randomized Feasibility Trial of Elastance-Directed Intrapleural Catheter or Talc Pleurodesis in Malignant Pleural Effusion

Background: Talc slurry pleurodesis (TSP) prevents recurrence of symptomatic malignant pleural effusion (MPE) in 71% to 78% patients. Nonexpansile lung (NEL) frequently accounts for TSP failure but is often occult predrainage, impairing selection of patients. NEL is associated with high pleural elastance (P_EL), but technical limitations have hampered the development of P_EL as a predictive NEL marker. We performed a single-center, randomized, controlled, open-label feasibility trial of EDIT (elastance-directed indwelling pleural catheter or TSP) management, using a novel digital manometer and a new definition of high P_EL.

Methods: Patients with symptomatic MPE were randomized 1:1 between EDIT and standard care (TSP). EDIT involved P_EL assessment during large-volume thoracentesis; patients with high P_EL (maximum P_EL sustained over 250 mL [MaxP_EL250] ≥ 14.5 cm H₂O/L) were allocated to immediately receive an indwelling pleural catheter; the remainder underwent immediate drain placement for TSP. The primary outcome measure was recruitment feasibility, defined a priori as 30 patients over 12 months. Secondary outcomes included safety, technical reliability, and the aspiration volume required to detect high P_EL. The accuracy of the P_EL definition for NEL was analyzed post hoc.

Results: Thirty-one patients were randomized (one allocation failure) over 12 months. P_EL assessment (mean duration, 33 minutes) was successful in 13 of 15 patients (87%). No directly attributable serious adverse events occurred. High P_EL was detected in seven of 13 patients (54%), associated with 100% sensitivity and 67% specificity for NEL, and was first detected at a median volume of 325 mL (range, 250-800 mL).

Conclusions: A phase 3 trial testing the effect of EDIT management on symptomatic MPE recurrence following TSP is feasible.

Trial registry: ClinicalTrials.gov; No.: NCT03319186; URL: www.clinicaltrials.gov.