Improved Cholesteatoma Removal with CADISS: A Quantitative Ultrastructural Comparison Using VP-SEM

Area of Science:

• Otolaryngology
• Surgical Technology
• Microscopy

Background:

• Cholesteatoma is a destructive middle ear disease requiring meticulous surgical excision.
• The chemically assisted dissection (CADISS) system utilizes Mesna (5%) to improve tissue separation and reduce residual disease.
• Preserving auditory function and preventing recurrence are key surgical goals.

Purpose of the Study:

• To quantitatively compare the cholesteatoma cleaning efficiency of CADISS-assisted dissection versus conventional manual dissection.
• To evaluate residual cholesteatoma on incus bone surfaces using ultrastructural analysis.
• To correlate surgical technique with postoperative residual disease and recurrence rates.

Main Methods:

• Retrospective analysis of 67 human incus samples from cholesteatoma surgery.
• Variable pressure scanning electron microscopy (VP-SEM) for ultrastructural imaging of hydrated samples.
• Quantitative analysis of clean area/total area ratios and qualitative assessment of residuals.
• Postoperative MRI follow-up at 1 month to detect residual cholesteatoma.

Main Results:

• CADISS-assisted dissection yielded significantly higher clean area/total area ratios (0.2095 vs. 0.0478, p < 0.0001).
• Qualitative imaging revealed fewer residual cholesteatoma fragments > 1 mm in the CADISS group (9% vs. 77%).
• MRI follow-up showed a lower recurrence rate in the CADISS group (3.1%) compared to manual dissection (11.4%).

Conclusions:

• CADISS-assisted dissection offers superior cholesteatoma debris removal compared to manual techniques.
• VP-SEM imaging and clinical outcomes support the efficacy of CADISS.
• This method holds potential for improving surgical outcomes and reducing recurrence in middle ear cholesteatoma surgery.