1. Posterior mesotympanic retractions: the contemporary surgical management Ashish Vashishth Department of Otorhinolaryngology and Head and Neck Surgery, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi, India

2. Disclosures None

3. Introduction The management of posterior or postero-superior mesotympanic retraction pockets(PSRPs) has always been debatable. Management methods Conservative/regular follow up and assessment for visibility of depth/fundus intact canal wall mastoidectomy/combined approach tympanoplasty retrograde canal wall down mastoidectomy PSRP excision with grafting for limited retractions

4. Limitations of current methods - surgery of the mastoid entails disruption of normal anatomy far from site of pathology in cases of limited retractions, without significant benefit. - reconstructed graft (fascia/perichondrium) remains amenable to re-retraction or atrophy due to persistent negative middle ear pressure - less than optimal ossicular reconstruction methods in case of ossicular discontinuity/erosion - oblique angle of stapes suprastructure with relation to plane of tympanic membrane - scar tissue induced contractures in middle ear post tympanoplasty can affect the final position of prosthesis and lead to suboptimal results

5. Purpose To evaluate the functional outcomes of surgical management of limited postero- superior mesotympanic retraction pockets using combined transcanal microscopic and endoscopic tympanoplasty using full thickness cartilage palisades.

6. Materials and Methods Retrospective study at a tertiary referral center between 2011-2013 Inclusion criteria 25 Chronic otitis media patients with posterior or postero-superior mesotympanic retraction pockets limited to attic or aditus ad antrum Exclusion criteria extension of epithelium/cholesteatoma to antrum and beyond, requiring canal wall down mastoidectomy patients with sensorineural hearing loss

7. Criteria for surgical intervention lack of visibility of fundus of pocket on examination under microscope Fixity of retraction to the incus or stapes Presence of otorrhoea Conductive hearing loss

8. Surgical technique Transcanal approach Permeatal or limited endaural incision was used for most cases. No cortical or controle hole mastoidectomy was performed in any case Flap elevation, canalplasty and postero-superior canal wall removal were performed under microscope. Curettes were used in most cases for removal of scutum whereas drill was used in cases where complete removal of scutum was required

9. Incus and malleus were removed in presence of ossicular discontinuity or significant extension of epithelium medial to ossicles Inspection and disease clearance from epitympanum, aditus and posterior mesotympanic recesses was assisted using 30° and 70° angled endoscopes. The antrum was inspected through the epitympanum using angled endoscopes successively using lateral semicircular canal as the landmark. No transcortical antrotomy was performed

10. Endoscopic images of the aditus and antrum via attic after ossicular removal

11. Ossicular reconstruction, wherever applicable, was performed using the FlexiBal titanium Clip PORP (KURZ Medical Inc.), a prosthesis designed by the Departments of Otolaryngology at Universities of Cologne and Dresden. ( Beutner D, Luers JC, Bornitz M, Zahnert T, Huttenbrink KB. Titanium Clip Ball Joint: A Partial Ossicular Replacement Prosthesis) No stapes head erosion necessitating total ossicular replacement was observed in the series.

12. Micro ball joint in the implant headplate permits its alignment with the plane of tympanic membrane despite the oblique axis of stapes and micro- adjustments of the headplate with placement of cartilage assembly on it without implant displacement. Self-retaining clip permits stable intra-operative coupling with the stapes.

13. The micro ball joint enables a final angle of 60 – 90 between the shaft and headplate of the implant. This enables the headplate to adjust itself along the tympanic membrane, thus maintaining contact with the tympanic membrane during phases of healing and scarring. Te resistance created by ball joint impedes transfer of large non acoustic movements from tympanic membrane to the inner ear.

14. Video

15. The Kurz Titanium Flexi Bal Clip PORP

16. Video

17. Technique of cartilage harvesting and shaping Tragal cartilage was harvested from incision preserving tragal dome in permeatal cases or from the endaural lempert’s 2 incision. Perichondrium was removed from the convex side. Full thickness broad palisades were cut using a no.15 blade. The side facing middle ear was kept bare, whereas the side facing external auditory canal was covered with attached perichondrium.

18. Tympanic membrane was reconstructed using broad full thickness tragal cartilage palisades with perichondrium attached on lateral side, placed onto the implant headplate, or in an underlay manner at the level of posterior bony annulus in presence of an intact ossicular chain. Gelfoam was used in the middle ear to support palisades in presence of intact ossicular chain. Attic reconstruction was done using tragal cartilage, wherever applicable. Post-operative graft status, evidence of re-retraction, implants extrusion and hearing outcomes using pure tone audiometry were evaluated after 24 and 48 weeks

19. Results 18/25(72%) patients underwent type 3 tympanoplasty 4/25(16%) patients underwent type 1 tympanoplasty consequent to ossicular preservation. No ossicular reconstruction performed in two cases due to footplate fixity and in one case due to footplate erosion with perilymph leak. Significantly less scutum removal was required in cases where endoscopy was used for inspection. The graft take-up rate was 88% (22/25) at the end of 1 year. Two patients had graft defects following profuse post- operative otorrhoea, whereas one patient developed retraction leading to atrophy and eventual perforation.

20. The mean pre and post-operative air-bone gap was 33.4 dB and 10.2 dB respectively, as pure tone averages at 500, 1000, 2000 and 4000 Hz. No implant extrusion was observed by the end of 1 year. Patients with totally transcanal or endaural procedures reported lesser post-operative discomfort and earlier return to work as compared to patients where postaural incision was used.

21. Post-operative tympanic membrane with well epithelized cartilage palisades after 1 year

22. Post-operative retraction after 12 months of surgery

23. Conclusions Combined transcanal approach to microscopic and endoscopic excision of limited mesotympanic retractions is minimally invasive and allows functional preservation of the mastoid anatomy. Ossicular preservation provides optimum hearing outcomes with reconstruction of drum using full thickness cartilage palisades to prevent future or recurrent retractions. A type 3 reconstruction, in presence of ossicular discontinuity, using the titanium Flexi Bal Clip PORP provides the maximum functionality in passive middle ear impants and most contemporary ossicular reconstruction in form of stable intra- operative coupling and dynamic post-operative acoustic transmission, particularly in presence of middle ear pressure changes.

24. References Huttenbrink KB, Zahnert T, Wustenberg EG, Hofmann G. Titanium clip prosthesis. Otol Neurotol 2004;25:436-42 Murbe D, Zahnert T, Bornitz M, Huttenbrink KB. Acoustic properties of different cartilage reconstruction techniques of the tympanic membrane. Laryngoscope 2002;112:1769-76 Bernal-Sprekelsen M, Romaguera Lilso MD, Sanz Gonzalo JJ. Cartilage palisades in type III tympanoplasty: anatomic and functional long term results. Otol Neurotol 2003;24:38-42 Hess-Erga J, Moller P, Vassbotn FS. Long-term hearing result using Kurz titanium ossicular implants. Eur Arch Otorhinolaryngol 2013;270:1817-21 Beutner D, Luers JC, Bornitz M, Zahnert T, Huttenbrink KB. Titanium Clip Ball Joint: A Partial Ossicular Replacement Prosthesis Caye-Thomasen P, Anderson J, Uzun C, Hansen S, Tos M. Ten-year results of cartilage palisades versus fascia in eardrum reconstruction after surgery for sinus or tensa retraction cholesteatoma in children. Laryngoscope 2009;119:944-52