Rigid Autofluorescence Imaging as a Tool for Identifying Cholesteatoma During Otologic Surgery: Initial Ex Vivo Findings.

Abstract

This study aims to determine whether rigid autofluorescence imaging can differentiate cholesteatoma from surrounding tissues to reduce residual disease after cholesteatoma surgery. Ex vivo proof-of-principle study. Erasmus University Medical Center, Rotterdam, the Netherlands. Autofluorescence signals of cholesteatoma, mucosa, and bone were measured using confocal microscopy to confirm distinguishable spectral differences. Subsequently, rigid autofluorescence imaging with specific filter settings (λ_e = 405 nm and λ_d > 570 nm) was applied to 14 resected surgical specimens to obtain signal intensity and tissue-specific fluorescence ratios. Cholesteatoma matrix without keratin exhibited a significantly higher autofluorescence intensity compared to mucosa (P < .03), with a cholesteatoma-to-mucosa ratio of 2.15. Similarly, autofluorescence intensity was elevated in the matrix with keratin (ratio: 2.25, P = .03) and perimatrix with keratin (ratio: 2.29, P = .04) relative to mucosa. Perimatrix without keratin showed a nonsignificant trend (ratio: 1.85, P = .06). Although cholesteatoma and bone showed no significant difference, this is clinically less relevant as bone is easily identifiable during surgery. Rigid autofluorescence imaging demonstrates significant potential for improving cholesteatoma surgery by reliably differentiating cholesteatoma matrix, both with and without accumulated keratin, from mucosa, showing 2.25- and 2.15-fold higher signal intensities, respectively. This technique could assist otologic surgeons in achieving more complete resections, thereby reducing residual disease rates while preserving surrounding structures. Future research should focus on optimizing the technology for in vivo application, particularly for detecting small cholesteatoma fragments, and further evaluate factors influencing specificity and sensitivity in clinical practice.