This is a retrospective video-based study that developed and validated a classification system for laser-induced tissue effects from a 445 nm blue light laser (BLL) used for laryngeal pathologies by multiple academic laryngologists. The primary focus was on establishing a framework for rating tissue effects, with secondary outcomes assessing inter- and intra-rater reliability.
The authors report that consensus among combined reviewers was achieved in 89% (58 of 65) of cases. In 11% (7 of 65) of cases, complete consensus was not achieved, and among these, 57% (4 of 7) of incorrect ratings were for clips illustrating the BLL-2 classification. Intra-rater reliability among reviewers was 100%.
Key limitations noted by the authors include the retrospective design, video-based review, expert consensus development, and that the study was limited to clips from procedures by multiple academic laryngologists. The classification system is based on expert consensus and reliability testing; generalizability to other settings is not established.
Practice relevance is restrained: the rating system can be used to facilitate future systematic study of outcomes and effective communication between laryngologists and trainees. This study does not establish causation for treatment outcomes.
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Objective: Only preliminary investigations on the use of the 445 nanometer wavelength blue light laser (BLL) for various laryngeal pathologies have been described. Currently, no standard exists for reporting treatment technique and tissue effect with this modality. Here, we aim to establish and validate a classification system to describe laser-induced tissue effects. Study Design: Retrospective video-based study for classification development and reliability validation. Methods: Video recordings from procedures performed with the BLL by multiple academic laryngologists were retrospectively reviewed. A preliminary 6-point classification (BLL 1-6) was developed based on expert consensus. Thirteen additional procedural clips were independently rated utilizing the classification schema to assess perceived tissue effect, and measure inter- and intra-rate reliability. Results: The final 5-point classification system (BLL 1-5) included angiolysis, blanching, tissue vaporization, ablation with mechanical tissue removal, and cutting. The consensus of the combined reviewers in rating all cases was 89% (58 of 65). Complete consensus was not achieved in 11% (7/65) of cases. Of those incorrect, 57% (4/7) were of clips illustrating the BLL-2 classification. Intra-rater reliability amongst the reviewers was 100%. Conclusion: Tissue effect of the 445 nm blue light laser can reliably be standardized with this proposed classification system. This rating system can be used to facilitate future systematic study of outcomes and effective communication between laryngologists and trainees.