Cryo- versus surgical lung biopsy for diagnosing interstitial lung disease (ILD): the COLD RCT

Abstract

<b>Background</b> In ILD patients with an indication for lung biopsy, surgical lung biopsy (SLB) has high diagnostic yield but is associated with significant morbidity and requires in-hospital stay. Transbronchial cryobiopsy (TBCB) is a less invasive outpatient alternative to SLB. The optimal diagnostic strategy is unknown. <b>Aim</b> To compare 2 diagnostic strategies: TBCB, if inconclusive followed by SLB (cryo-strategy) versus immediate SLB (surgery-strategy). <b>Methods</b> Randomized study in 5 Dutch hospitals(NL7634). Consecutive ILD patients with an indication for lung biopsy were randomized. Primary endpoint: (prolonged) chest tube drainage, as surrogate outcome for patient burden, defined as: proportion of patients requiring post-procedural chest tube (cryo-strategy) or prolonged (&gt;24h) chest tube drainage (surgery-strategy). Secondary endpoints included diagnostic yield, in-hospital stay and adverse events. <b>Results</b> 55 patients (80% male; Age 66+7 years; FVC 85%+9%; DLCO 55%+11%) were randomised: 28 to cryo-strategy (step-up SLB was performed in 3 after inconclusive TBCB) and 27 to surgery-strategy. 14% patients in de cryo-strategy required (prolonged) chest tube drainage (95%CI 1.3-27; n=4) versus 41% in the surgery-strategy (95%CI 22-59; n=11; p=0.028); diagnostic yield for MDT diagnosis was 89% (72-98) and 88% (74-100); median in-hospital stay 0 days (range: 0-14) and 3.5 days (range: 1-16); serious adverse events (other than chest tube drainage) 0.04%(n=1) and 25%(n=6), respectively. <b>Conclusion</b> A cryobiopsy centered diagnostic strategy, if inconclusive followed by SLB, results in significant reduction of adverse events and hospital stay, while diagnostic yield of MDT diagnosis appears similar.