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Video

Otology/Neurotology

(A832) Hydroxyapatite Powder Coating: A Technique for Long-Term Visualization of Soft-Tissue Grafts Following Tegmen Repair

Monday, October 13, 2025
12:00 PM - 1:00 PM EDT
Location: OTO EXPO, Posters

    Presenting Author(s)

  • Katelyn N. Robillard, MD, PhD

    ENT Resident
    Louisiana State University Health Sciences Center
    Baton Rouge, Louisiana, United States

    • Co-Author(s)

  • Omar W. Azmeh, MS

    Medical Student
    Louisiana State University Health Sciences Center School of Medicine
    New Orleans, Louisiana, United States

    • Senior Author(s)

  • Moises A. Arriaga, MD

    Professor of Otolaryngology-Head and Neck Surgery
    Louisiana State University School of Medicine
    Metairie, Louisiana, United States

Disclosure(s):
Katelyn N. Robillard, MD, PhD: No relevant relationships to disclose.
Omar W. Azmeh, MS: No relevant relationships to disclose.
Moises A. Arriaga, MD: No relevant relationships to disclose.


Introduction: Postoperative imaging following tegmen repair may identify persisting bone defects despite adequate repair with non-radiopaque materials. Our institution utilizes a 3-layer repair technique whereby autologous bone is placed between 2 layers of acellular dermis (AD). To enhance postoperative visualization on CT scans, we developed a novel method of coating the AD with hydroxyapatite (HA) powder prior to implantation. The goal of this study was to determine the duration of graft visibility on CT following tegmen repair.

Methods: A single-center, retrospective cohort study was performed on a convenience sample of 100 patients who underwent tegmen repair by the senior author between September 2021 and July 2024. Postoperative temporal bone CT scans were analyzed in the coronal plane using Visage Imaging software. A circular region of interest tool set at 1.5 mm2 was used to measure radiodensity at 3 distinct locations (lateral edge, middle, medial edge) on the superior layer of AD. The average of these 3 values was then compared to subsequent imaging to determine change in radiodensity over time using linear regression analysis.

Results: In the 100 cases 65% were female, 57% left-sided, and average age at time of surgery was 57 years. All procedures received a postoperative CT on day 1, with average radiodensity of the HA-coated AD being 285 HU (range 79 HU to 733 HU). 63 cases had additional imaging up to 28 months after surgery. Regression analysis demonstrated a positive relationship between time and change in radiodensity (slope = 7.28; 95% CI 3.10 to 11.46; t79 = 3.47; p 0.00085; y=7.28x-33.89; r2 = 0.13).

Conclusions: Coating AD with HA powder at the time of surgery leads to adequate visualization on CT for at least 2 years. Such HA-coating strategies can be considered for any dural repair material which would be particularly valuable for properly diagnosing recurrence of encephaloceles in patients previously operated elsewhere. In our institution, this technique plays an important role in surveillance and avoidance of revision surgery in patients with adequate tegmen repair.