Evaluation of middle ear reconstruction by endoscopic Optical Coherence Tomography
Introduction Endoscopic Optical Coherence Tomography (eOCT) allows high-resolution 3-dimensional imaging of the tympanic membrane and the adjacent areas of the middle ear. Doppler-OCT enables oscillation measurement. Thus, the postoperative outcome of tympanoplasty can be evaluated.
Material and Methods 5 Patients were examined after tympanoplasty using eOCT. The system utilizes a near infrared laser with a central wavelength of 1300 nm and a working range of 8 mm. The thickness of the tympanic membrane and of the reconstruction were determined as well as the coupling of the prostheses. Furthermore, the oscillation of the reconstructed tympanic membrane and of the prostheses was evaluated. The results were compared to the audiometric outcome.
Results The measurements could be performed in all patients. The tympanic membranes showed different oscillation patterns and oscillation amplitudes corresponding to the thickness of the tympanic membrane and to the extend of the reconstruction. The thickness could be determined up to 800 µm, the greatest value above a prosthesis was 700 µm. The results correlate with the audiometric outcome.
Conclusion EOCT supports the middle ear surgery by providing advanced diagnostic tools, especially the measurement of oscillation behaviour, morphology of the tympanic membrane and coupling of prostheses. Thereby, causes for remaining air-bone-gap postoperatively and approaches to an improvement of middle ear reconstruction can be determined.
10 June 2020 (online)
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