1. TUFIK SB, PASSOS UL, CEVASCO FKKI Control #: 1831, eEdE #: eEdE-157
POST-OPERATORY EVALUATION OF OTOSCLEROSIS: NORMAL FINDINGS AND COMPLICATIONS THAT RADIOLOGISTS SHOULD KNOW AND REPORT
TUFIK SB, PASSOS UL, CEVASCO FKKI
Control #: 1831, eEdE #: eEdE-157

2. DISCLOSURE
None of the authors has any conflict of interest to disclose.

3. CONTENTS Methods; Results; Introduction to otosclerosis;
Normal post-operatory imaging;
Complications.

4. METHODS
28 patients with 37 otosclerosis lesions treated with surgical procedures;
Scanned on 16-channel Siemens CT and 64-channel GE CT from 2010 to 2015;
Centro de Diagnósticos Brasil in Sao Paulo;
Analyzed by two ENT radiologists with more than 10 years experience.

5. RESULTS Normal positioned prosthesis 10 Misplacement of the prosthesis11
Labyrinthitis ossificans 8
Incus luxation 2
Incus interposition
Pneumolabirinth 1
Development of reparative granulomas
Proliferation of otosclerosis around the prosthesis
Prosthesis fracture

6. RESULTS Misplacement of the prosthesis 11 Labyrinthitis ossificans 8
Incus luxation 2
Incus interposition
Pneumolabirinth 1
Development of reparative granulomas
Proliferation of otosclerosis around the prosthesis
Prosthesis fracture

7. INTRODUCTION TO OTOSCLEROSIS
Autosomal dominant osteodystrophy;
Usually occurs in the 2nd and 4th decades of life;
Progressive hearing loss (conductive, sensorineural or mixed);
More common in Caucasians and women;
Commonly bilateral (85%);
Types: fenestral and retrofenestral.

8. INTRODUCTION TO OTOSCLEROSIS
Stapedectomy: removal of the stapes, replacing it with a micro prosthesis.
Stapedotomy: creation of a small hole in the fixed stapes and inserting a piston-like prosthesis.
Main purpose: restore ossicular continuity.

9. EVALUATION Positioning of the prosthesis;
Remaining's of the ossicular chain;
Surgical access;
Integrity of the membranous labyrinth;
Signs indicative of fibrosis;
Tympanic cavity pneumatization.

10. NORMAL POST-OPERATORY
Case 1: Left Stapedectomy and Prosthesis Insertion
Axial CT: notice that the metallic prosthesis is well inserted, in contact with the oval window, not penetrating it, and also in contact with the incus.

11. NORMAL POST-OPERATORY
Case 1: Left Stapedectomy and Prosthesis Insertion
Coronal reformat: notice that the metallic prosthesis is well inserted, in contact with the oval window, not penetrating it, and also in contact with the incus.

12. NORMAL POST-OPERATORY
Case 1: Left Stapedectomy and Prosthesis Insertion
Sagital reformat: notice that the metallic prosthesis is well inserted, in contact with the oval window, not penetrating it, and also in contact with the incus.

13. NORMAL POST-OPERATORY
Case 2: Bilateral Stapedectomy and Prosthesis Insertion
Axial CT: notice that the metallic prosthesis are well inserted bilaterally.

14. Case 3: Prosthesis Luxation
COMPLICATIONS
Case 3: Prosthesis Luxation
Oblique reformat: a prosthesis like this one is making contact with the oval window, but not connecting with the ossicular chain.

15. Case 4: Prosthesis Luxation
COMPLICATIONS
Case 4: Prosthesis Luxation
Axial CT: prosthesis lying on the posterior wall of the tympanic cavity (arrow), not in contact with the oval window nor the ossicular chain.

16. COMPLICATIONS Case 5: Artifacts
Axial CT: artifacts derived from the metallic prosthesis simulate pneumolabirinth and luxation inside the right vestibule.

17. COMPLICATIONS Case 5: Artifacts
Coronal reformat: however, it is possible to notice that the prosthesis is well placed and there is no pneumolabirinth.

18. COMPLICATIONS Case 5: Artifacts
Sagital reformat: again, it is possible to notice that the prosthesis is well placed and there is no pneumolabirinth.

19. COMPLICATIONS Case 6: Strikes
Artifacts derived from metallic prosthesis, such as strikes, may impact the evaluation of its relation to the oval window, leading to a false-positive of prosthesis luxation inside the vestibule.

20. Case 7: Luxation with Pneumolabirinth
COMPLICATIONS
Case 7: Luxation with Pneumolabirinth
Axial CT: notice that the prosthesis is penetrating the vestibule and there is air inside it too.

21. Case 7: Incus Luxation with Topic Prosthesis
COMPLICATIONS
Case 7: Incus Luxation with Topic Prosthesis
Axial CT and coronal reformat: notice that the incus is misplaced (blue arrow head) and there is labyrinthitis ossificans (red arrow head). Arrow indicating prosthesis.

22. Case 8: Labyrinthitis Ossificans
COMPLICATIONS
Case 8: Labyrinthitis Ossificans
Axial CT: topic left prosthesis (arrow) with labyrinthitis ossificans (arrow head).

23. Case 9: Proliferation of Otosclerosis Around the Prosthesis
COMPLICATIONS
Case 9: Proliferation of Otosclerosis Around the Prosthesis
MIP reformat: notice the hyperatenuating tissue circumscribing the prosthesis (arrow).

24. COMPLICATIONS Case 10: Luxation
MIP reformat: bilateral stapedectomy and right prosthesis luxation (arrow). The left one is well placed (arrow head).

25. Case 11: Incus Interposition
COMPLICATIONS
Case 11: Incus Interposition
Axial CT: stapedectomy with incus interposition (rotation of the incus with insertion straight to the oval window - arrow).

26. Case 12: Prosthesis Luxation
COMPLICATIONS
Case 12: Prosthesis Luxation
Axial CT: non-metallic prosthesis is inserted more than 2mm into the vestibule. There is also fibrous tissue around the prosthesis.

27. Case 13: Topic Prosthesis
COMPLICATIONS
Case 13: Topic Prosthesis
Coronal reformat: prosthesis replaces the entire ossicular chain.

28. Case 14: Prosthesis Fracture
COMPLICATIONS
Case 14: Prosthesis Fracture
Axial CT: prosthesis fracture – discontinuation of the metallic and non-metallic segments (arrow). The prosthesis size in relation to a credit-card (arrow head).

29. Case 15: Reparative Granulomas
COMPLICATIONS
Case 15: Reparative Granulomas
Oblique MIP: presence of granuloma tissue around the inferior-displaced prosthesis and obliterating the oval window.

30. Case 15: Reparative Granulomas
COMPLICATIONS
Case 15: Reparative Granulomas
Oblique MIP: presence of granuloma tissue around the inferior-displaced prosthesis and obliterating the oval window.

31. REFERENCES
Ukkola-Pons E, Ayache D, Pons Y, Ratajczak M, Nioche C, Williams M. Oval window niche height: quantitative evaluation with CT before stapes surgery for otosclerosis. AJNR Am J Neuroradiol 2013;34(5):1082-5
Purohit B, Hermans R, Op de beeck K. Imaging in otosclerosis: a pictorial review. Insights Imaging 2014;5:
Révész P, Liktor B, Liktor B, Sziklai I, Gerlinger I, Karosi T. Comparative analysis of preoperative diagnostic values of HRCT and CBCT in patients with histologically diagnosed otosclerotic stapes footplates. Our Arch Otorhinolaryngol Jan 6;273(1):63-72
Rudic M, Keogh I, Wagner R, Wilkinson E, Kiros N, Ferrary E, Sterkers O, Bozorg Grayeli A, Zarkovic K, Zarkovic N. The pathophysiology of otosclerosis: review of current research. Hear Res Dec;330(Pt A):51-6
Phillips GS, LoGerfo SE, Richardson ML, Anzai Y. Interactive web-based learning module on CT of the temporal bone: anatomy and pathology. RadioGraphics 2012;32:E85-E105