The middle ear ossicles are uniquely shaped structures that collect sound waves from the tympanic membrane and conduct them to the inner ear. Malleus has a catenary lever mechanism in enhancing the sound pressure levels of the sound arriving at the tympanic membrane. In review of literature, many authors emphasized the role of malleus in post ossiculoplasty hearing gain.[1],[2] The presence of an anteriorly positioned malleus makes it a difficult situation to the otologist during ossiculoplasty. Therefore, Vincent et al.[3] invented malleus relocation by relocating malleus and making it perpendicular to stapes head or footplate using both partial ossicular replacement prosthesis (PORP) and total ossicular replacement prosthesis (TORP) during tympanoplasty or revision stapes surgery.

After that, multiple authors used this technique in revision stapedectomy and in mastoidectomy surgery for ossicular reconstruction with reshaped incus or with TOPR or PORP.[3],[4],[5],[6] None of the previous authors study hearing outcome after the use of malleus relocation technique with autologous incus in cases with chronic otitis media with perforation.

The aim of this study is to report the method of malleus relocation with auto-incus in ossiculoplasty in cases with chronic suppurative otitis media and to measure the audiological outcome of this technique.

This is a retrospective study that included all patients who underwent ossiculoplasty using malleus relocation technique surgery from 2012 to 2019 for chronic otitis media. The study was conducted in the Otorhinolaryngology and Head-and-Neck Surgery Department of Al-Nahdha Hospital. The data collected from patient file recorde system.

All cases included in the study had long process of incus erosion, had perforation, age more than 14 years, no previous ear surgery, and should have preoperative pure-tone audiometry (PTA) and postoperative PTA (2 months, 6 months, and 1 year). Any patient with missing data will be excluded from the study.

Ossicular defect was classified according to Austin's classification of ossicular defects as modified by Kartush.[7],[8]

Audiometric assessment

Audiometric evaluation included preoperative and postoperative PTA at (3, 6, and 12 months). PTA was reported according to the American Academy of Audiology Guideline. The average air-bone gap (ABG) for four frequencies (at 500, 1000, 2000, and 4000 Hz) was calculated along with air-conduction gain.[9]

Data were collected and analyzed in SPSS version 21. Confidence interval, mean, and median are used to calculate the pre- and postoperative ABG as sample size is small.

Surgical technique

After elevating tympanomeatal flap and checking ossicles status, malleus freed from tympanic membrane. Incus removed and reshaped to be used for reconstruction at the end. Tensor tympani tendon cut at the nearest point of its insertion to the malleus handle. Then, malleus retracted posteriorly till it become directly above the footplate or stapes head by using right angle hook on anterior malleus neck. It is advised to overstretch the anterior malleolar ligament to prevent anterior retraction later. Superior ligament of malleus should be preserve to maintain position of malleus. Post-operative result show in [Figure 1].

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Reshaped incus is placed first on the stapes head or footplate. Then, the relocated malleus handle is placed over the groove on the incus. The tympanomeatal flap with graft returned back to it is place.

Ethical clearance

Ethical approval of this study((Malleus Relocation in Ossicular Reconstruction by Using Autologous Incus: New Technique in Ossiculoplasty, Al-Nahdha Hospital Experience) (MOH/CRS/20/24218) was provided by research and ethical committee of Directorate General of Planning and Studies, Ministry of Health, P.O. Box 393, Postal Code 113,Muscat, Oman On February 2021.

Twelve patients underwent malleus relocation. Eleven patients were included in the study. This is reason why we excluded one patient. Seven patients came for follow-up after 12 months.

The sex ratio was 45% female and 55% male. 31.5 years is the mean age (range: 14–67 years). Ten cases are in Austin–Kartush group A and two cases are in group B. All cases had a long process of incus erosion and had perforation. None of the cases had cholesteatoma. Autologous incus was used in all cases except one case TORP was used as incus.

No intraoperative complications or postoperative complications encounter (such as facial nerve injury, SNH, and failure of graft uptake). The mean duration of follow-up is 18.4 months.

Audiometric outcome

The mean postoperative average ABG at 12 months is 11.29 dB comparing to 34.92 dB preoperatively. Around 66% of postoperative average ABG is less than 20 db. [Table 1] shows comparison preoperatively, 3 months, and 12 months postoperatively average ABG.

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There is no significant difference in bone conduction postoperative when compared with preoperative bone conduction with P value of 0.747.

Postoperative AC threshold improved in in 62.5% and 66.7% of cases (at 3 months postoperative and 12 months postoperative, respectively) with more than 20-dB improvement with a mean of 28 dB at 3 months and 28 dB at 12 months.

Sound transmission between tympanic membrane and inner ear is one of the main goals of tympanoplasty with ossiculoplasty surgery.[4] In order to give better hearing outcome, the presence of malleus is a must to reach this goal. As in a study done by S. Ablul et al., they compared postoperative hearing outcomes between group of patients found with presence and another group with absence of malleus. They found that hearing outcome is significantly better in group with presence of malleus (7). In addition, Ahmet et al. compared ossiculoplasty outcome when prosthesis assembly under the malleus (n = 36) and under the tympanic membrane directly (n = 47). They found that hearing outcome was significantly better in group with prosthesis under the malleus.[4] The presence of malleus is not the only factor for improving the hearing, but also its location in relation to stapes axis plays a rule. When the angle between the malleus and axis of stapes or footplate is more than 45°, the force of vibration from tympanic membrane to footplate is lost in inefficient rocky motion. Comparatively, when angle between the malleus and axis of stapes is zero, the force of vibration is transmitted completely to the inner ear.[3],[8],[10] From this idea, Vincent et al. invented the malleus relocation technique to make malleus at zero angle from stapes axis in order to improve hearing outcome.

A previous study used the same technique in revision stapedectomy,[3],[5],[6] and in mastoidectomy with and without cholesteatoma.[4],[8],[11] None of the previous studies used this technique in cases with chronic suppurative otitis media with perforation like in our study. In addition, in our study, we used autologous incus for assembly instead of prosthesis. With that, no risk of prosthesis extrusion is encountered. Furthermore, incus is costless in comparison with prosthesis.

The hearing outcome from our technique is consistence with the result of other studies using malleus relocation. In our study we use the malleus relocation technique with auto-incus in cases with chronic suppurative otitis media with perforation in compared to previous studies in which they used this technique with prosthesis in case of revision stapes surgery[3] or in case of cholesteatoma.[6] Our mean ABG is 11dB, which is the same result to what Ghonim et al. get by using malleus relocation with incus interposition in cases of revision stapedectomy (mean ABG is 11.5 dB). In comparison, the result of prosthesis use (like Vincent et al.[3] and Ahmet et al.[4] mean ABG 14dB and 10.4 dB, respectively) verses use of incus for ossiculoplasty with malleus relocation(our study and Ghonim et al.[6] using incus interposition (11 dB and 11.5 dB, respectively) are almost same result. It may conclude that using incus for ossiculoplasty gives the same result with using prosthesis and is no risk of extrusion that encounters with prosthesis and cost less.

Malleus relocation with auto-incus ossiculoplasty showed in this study is safe and gives a good hearing outcome.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.