Bronchoscopy for management and identification of etiology of right middle lobe syndrome: Analysis of 66 cases.

Abstract

Right middle lobe (RML) syndrome is a recurrent or chronic obstruction of the RML causing atelectasis of the right middle lobe due to mechanical and nonmechanical etiologies. The consequences of untreated RML syndrome range from chronic cough to post-obstructive pneumonia and bronchiectasis. We report here our bronchoscopy experience in patients with RML syndrome. We conducted a retrospective study of adult patients who underwent bronchoscopy for RML syndrome at Rabin Medical Center from 2008 through 2022. Demographic data and medical history, bronchoscopy findings and procedures, and follow-up results were collected. A total of 66 patients (57.6% male, mean age 63 ± 13 years) underwent bronchoscopy for RML syndrome during the study period. Bronchoscopy revealed a mechanical etiology in 49 (74.2%) cases, including endobronchial mass (21, 31.8%) and external compression (7, 10.6%). Malignancy was identified in 20 (30.3%) cases. In 62 patients (93.9%), the bronchoscopy resulted in partial or complete reopening of the RML bronchus. The therapeutic bronchoscopic procedures were balloon dilatation (19), laser ablation (17), mechanical debridement (12), endobronchial stent insertion (11), and cryoablation (6). Malignancy was identified as the etiology of RML syndrome in approximately 25% of cases, suggesting bronchoscopy should be performed in every case of RML atelectasis. To our knowledge, this is the first reported series of endobronchial stenting of the RML bronchus in the context of RML syndrome.