Prevalence and Clinical Characteristics of Pediatric Lower Airway Malacia: Case Series from a Tertiary Center in Turkey.

Introduction: Lower airway malacia (LAM) is characterized by a reduction in the cross-sectional luminal area during quiet respiration. There is no gold standard diagnostic test; however, flexible fiberoptic bronchoscopy (FFB) is most frequently utilized. The exact prevalence and incidence of LAM are unknown. This study aimed to determine the prevalence rates of pediatric patients diagnosed with LAM, offer a detailed understanding of their demographic and clinical characteristics, and investigate distinctions between two specific types of LAM, namely, tracheomalacia (TM) and bronchomalacia (BM). Materials and Methods: Patients younger than 18 years diagnosed with LAM using FFB were included in this retrospective case series. Demographic and clinical characteristics and comorbid disorders were compared between patients with isolated BM and those with isolated TM or tracheobronchomalacia (TM/TBM). Results: Among 390 patients who underwent FFB, 65 (16.6%) were diagnosed with LAM, 16 (24.6%) with TM, and 56 (86.2%) with BM. The median age at diagnosis was 15 months. Among them, 59 (90.8%) had other comorbidities; gastrointestinal (GI) disorders were the most common (38.5%). The most common indications for bronchoscopy were recurrent/prolonged lower respiratory tract infections (LRTI) or wheezing (43.1%), while the most frequently observed respiratory physical examination finding was stridor (35.4%). Patients with TM/TBM had significantly higher frequencies of premature births, stridor, retraction, and GI disorders. Conclusion: Patients with stridor without typical laryngomalacia features or recurrent or prolonged LRTI should undergo prompt evaluation for LAM. The potential coexistence of GI disorders such as gastroesophageal reflux disease and swallowing dysfunction should also be considered.