Supplementary Material for: High-Impact Laryngotracheal Trauma: A Combined Narrative and Systematic Review Evaluating Gaps in the Current Laryngeal Injury Reporting System

Introduction: External neck trauma represents a potentially life-threatening clinical scenario. Blunt and penetrating injuries are the primary etiologies and may result in laryngeal injuries with concurrent tracheal involvement. High-impact or high-energy laryngotracheal trauma arises from diverse mechanisms; therefore, injury reporting must account for varied patterns and incorporate any synchronous tracheal injury, thereby establishing a more effective framework for managing complex external airway trauma.

Methods: Data from seven patients experiencing high intensity extreme laryngotracheal trauma were retrospectively analyzed, focusing on injury mechanisms, clinical presentations, site and grade of injury, imaging findings, management approaches and outcomes. In parallel, a PRISMA-guided search of PubMed, Embase, Scopus, and Web of Science (January 1980–April 2025) identified English-language case series reporting ≥5 patients. Data on injury mechanisms, Schaefer–Fuhrman grade, management, and outcomes were extracted.

Results: Seven cases of severe laryngotracheal trauma with varying mechanisms are presented, including closed glottis barotrauma, penetrating and blunt neck injury, accidental strangulation, prolonged labor and rough manipulation of a vertex presentation, clothesline injury and postintubation injury. The obstetric patient did not survive, while other patients underwent prompt airway stabilization with favorable functional outcomes.

The systematic review incorporated 11 studies: blunt trauma predominated (65–75 %), severe injuries (Schaefer grades III–V) accounted for one-half of cases, and overall mortality was 2 %. Tracheal extension, including cricotracheal separation was predominantly reported after high-impact blunt trauma in several studies.

Conclusion: The current classification system for external laryngeal trauma does not adequately capture the severity or anatomical complexities of high-impact laryngotracheal injuries. Our experience, supported by pooled literature data, underscores the limitations of laryngeal-only grading. Incorporating both the mechanism and extent of injury is essential to improve clinical decision-making, guide treatment strategies, and ultimately enhance patient outcomes and prognosis.