Performance of bilateral bronchoalveolar lavage during routine transplant surveillance bronchoscopy changes management.

Introduction: Surveillance bronchoscopy for lung transplant monitoring is a standard of care at most high-volume transplant centers, though methods vary based on institutional preferences. At our medical center, we perform bilateral bronchoalveolar lavage (BAL) and unilateral transbronchial biopsy. This study aims to determine how often bilateral BALs lead to a change in medical management. Methods: This is a single-center, retrospective cohort study enrolling 237 patients who underwent either bilateral or single lung transplant and who underwent 759 surveillance bronchoscopies with bilateral BALs from 2020 to 2025. Data collected included demographic data, cultured pathogens bilaterally, and pathology from unilateral biopsies. Different pathogens (DP) were defined by having two positive contralateral results with differing infectious agents, or a positive result in one lung with a negative result in the contralateral lung. Change in management was defined as either alteration of antibiotic coverage or immunosuppressive drugs. Results: Eighty-three bilateral BALs (10.9%) identified DP. Of these, 43 discordant findings (5.7% of all procedures) resulted in a change in management. All 43 of these changes involved initiation or adjustment of antimicrobial therapy, and 3 (7.0%) involved an adjustment in immunosuppression. Common pathogens that prompted management changes were Conclusions: Bilateral BALs identifies clinically significant DPs in over 1 in 10 surveillance procedures, with more than half of these findings directly altering patient care. Because the most common DP identified-