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Cochlear implantation in the presence of chronic suppurative otitis media

P. R. Axon, D. J. Mawman, T. Upile and R. T. Ramsden

The Journal of Laryngology & Otology / Volume 111 / Issue 03 / March 1997, pp 228 ­ 232DOI: 10.1017/S0022215100136977, Published online: 29 June 2007

Link to this article: http://journals.cambridge.org/abstract_S0022215100136977

How to cite this article:P. R. Axon, D. J. Mawman, T. Upile and R. T. Ramsden (1997). Cochlear implantation in the presence of chronic suppurative otitis media. The Journal of Laryngology & Otology, 111, pp 228­232 doi:10.1017/S0022215100136977

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The Journal of Laryngology and OtologyMarch 1997, Vol. I l l , pp. 228-232

Cochlear implantation in the presence of chronicsuppurative otitis media

P. R. AXON, D. J. MAWMAN*, T. UPILE, R. T. RAMSDEN

AbstractNine patients are presented who underwent cochlear implantation in the presence of chronic suppurativeotitis media. Four had a simple tympanic membrane perforation, four had a pre-existing mastoid cavityand one had cholesteatoma in the ear chosen for implantation. Patients with a simple perforation had astaged procedure with myringoplasty followed by cochlear implantation after an interval of three months.Patients with cholesteatoma or with an unstable mastoid cavity were also staged. A mastoidectomy orrevision mastoidectomy was performed with obliteration of the middle ear and mastoid using a superiorlypedicled temporalis muscle flap and blind sac closure of the external meatal skin. After a further sixmonths a second stage procedure was performed to confirm that the middle-ear cleft was healthy and toinsert the implant. Patients presenting with a stable mastoid cavity underwent obliteration of the cavityand implantation of the electrode as a one-staged procedure. To date there have been no seriousproblems such as graft breakdown, recurrence of disease or implant extrusion, and all patients areperforming well.

Key words: Cochlear implant; otitis media, chronic suppurative

IntroductionCochlear implantation has been shown to be areliable method of rehabilitation for certain pro-foundly deaf or deafened individuals Summerneldand Marshall (1995). Most patients assessed forcochlear implantation have middle ears which arefree of pathology, and in these patients cochlearimplantation is usually an uncomplicated single-staged operation. Chronic suppurative otitis media(CSOM) may be encountered however, either as thecause of the profound deafness or as a non-contributory chance finding. Such patients presentthe surgeon with a potential problem. Implantationof a foreign body into a septic field would seemfoolhardy with rejection a worrying possibility;furthermore the introduction of infection into thecochlea through the portal of implantation couldhave serious effects on the surviving neural elementswhich one hopes to stimulate with the implant. Thispaper describes the experience of the ManchesterRoyal Infirmary cochlear implant programme inmanaging nine patients with a profound hearing lossand CSOM.

Patients and proceduresBetween 1988 and 1996 a total of 157 patients

have received cochlear implants in the Manchester

Royal Infirmary/University of Manchester Pro-gramme (105 adults and 52 children). Of these,nine (5.7 per cent) were found to have CSOM eitheras the cause of the profound hearing loss or as anincidental finding. The obvious and usual reason forchoosing to implant an ear with CSOM was thepresence of a bilateral disease, but other indicationswere the presence of a relative contraindication onthe contralateral side eg labyrinthectomy forMeniere's disease (one patient), a congenital hearingloss (one patient) and the presence of some aidableresidual hearing (one patient). The ages of thepatients at implantation ranged from four to 62 yearsof age with a mean of 47.6 years. The duration ofprofound deafness ranged from one to 44 years witha mean of 11.5 years (Table I).

Standard pre-operative assessments included highdefinition axial CT scans of the petrous bones toexclude as far as possible new bone formation in thecochlea. Pure tone audiometry and speech audio-metry with, and without, hearing aids was performedtogether with assessment of lip-reading skills. Pro-montory stimulation testing was not routinelyperformed. Post-implantation testing included freefield audiometry (FFA) using warble tones at octavefrequencies from 250 Hz to 4000 Hz, Bench KowalBamford (BKB) sentence tests, and consonantconfusion tests (VCV). Environmental sound recog-

From the Department of Otolaryngology, Manchester Royal Infirmary and the ^Manchester cochlear implant programme*,Manchester, UK.Accepted for publication: 29 December 1996.

228

COCHLEAR IMPLANTATION IN THE PRESENCE OF CHRONIC SUPPURATIVE OTITIS MEDIA 229

TABLE IPATIENT DETAILS

Patient Age Duration of deafness CSOM Surgery Implant and insertion

123456789

53504476256594750

1361102445616

TM perforationTM perforationTM perforationTM perforationMastoid cavityMastoid cavityMastoid cavityMastoid cavityCholesteatoma

MyringoplastyMyringoplastyMyringoplastyMyringoplastySingle staged procedureSingle staged procedure2 staged procedure2 staged procedure2 staged procedure

Nucleus 22+5Medek8Nucleus 22+10Nucleus 22+0Nucleus 22+6Nucleus 18Nucleus 22+10Medel 8Medel 8

nition (ENV) was scored. The tests were carried outat one month, nine months and 18 months afterswitch on.

Four patients presented with simple perforationsof the tympanic membrane, without cholesteatoma.In none was the middle-ear disease responsible forthe hearing loss. In three there were bilateralperforations and in two of these individuals theperforations accompanied profound hearing loss ofunknown cause. The third was a child who had beendeafened, and suffered perforations during treat-ment for acute lymphoblastic leukaemia. In thefourth the contralateral ear had had a labyrinthect-omy for Meniere's disease and was consideredunsuitable. The perforations were repaired using atemporalis fascia underlay technique. Three healedat the primary operation. One required a revisionmyringoplasty because of graft failure. All had hadan intact drum for at least three months prior toimplantation. All patients had satisfactory CTimages with no sign of ossification in the lumen ofthe cochlea. Implantation was uncomplicated in allcases with complete insertion of the whole electrodearray.

Five patients had, or had had CSOM withcholesteatoma. In three, there was a stable, wellepithelialized mastoid cavity, and an air-containingmesotympanum. Two of these patients were treatedby employing a one-stage technique which entailedremoval of the fibro-epithelial lining of the middleear and mastoid, and the skin of the bony externalauditory canal, followed by obliteration of themastoid cavity with a pedicled temporalis muscleflap, which also serves to protect the electrode array,and a blind sac closure of the meatal skin. The thirdof this group had a two stage operation. At the firststage the fibro-epithelial lining of the mastoid cavitywas carefully elevated forwards up to, and beyond,the facial ridge and the middle ear opened to allowaccess to the round window. The flap of temporalismuscle was then cut and turned into the mastoidbowl and middle ear and the fibro-epithelial layerthen laid back over it. No blind sac closure wasperformed. At the second stage three months later,dissection deep to the muscle flap allowed easyaccess to the round window and a Nucleus 22channel device was inserted through a separatecochleostomy without difficulty. No problem wasenountered with any of these patients. All receivedNucleus 22 channel devices although only a partial

insertion (18 channels) was possible in patient 6(Table I).

Two patients had active CSOM at the time ofpresentation. Patient 8 a 45-year-old man had beenborn with a total right-sided hearing loss and lost thehearing in the left ear in adult life. An atticcholesteatoma was present, although it was by nomeans certain that this was responsible for the loss ofhearing. From consideration of neural plasticityissues it was felt that despite the CSOM the leftear was the preferred ear for implantation. A two-stage procedure was proposed. At the first operationa radical mastoidectomy was carried with eradicationof a fairly circumscribed cholesteatoma from theattic and mastoid antrum. The cavity was obliteratedusing a pedicled temporalis muscle flap and a blindsac closure performed. At the second stage proce-dure, after an interval of six months. A healthy cavitywas found. The muscle flap was dissected off thepromontory and a Nucleus 22 channel device wasinserted through a separate cochleostomy.

Patient 9 had had a bilateral CSOM withcholesteatoma treated with modified mastoidec-tomies was totally deaf. A Medel implant had beeninserted into the left side at another centre. Noattempt had been made to provide soft tissueprotection for the electrode array which was ineffect covered by no more than the epithelial liningof the middle ear and mastoid. Not many monthslater the patient presented with the electrodeprotruding from the external meatus, surroundedby pus and granulation tissue. A two-stage proce-dure was planned. At the first stage the electrodewas removed, and a revision mastoidectomy per-formed with eradication of residual cholesteatoma,obliteration the Eustachian tube opening, oblitera-tion of the mastoid with a temporalis muscle flap,and a blind sac closure of the external meatus. Onthis occasion a silastic sheet was placed between themuscle flap and the promontory, to facilitate accessat the second stage. The second operation wasperformed after a further six months. No problemwas found in identifying the promontory. The firstimplant had been inserted through the roundwindow. The replacement, also a Medel device wasinserted through a separate cochleostomy in front ofthe round window. Despite the fact that the scalahad been open for at least six months there was verylittle fibrosis in its lumen and, such as there was, wasby-passed by the cochleostomy. The ear healeduneventfully.

230 P R. AXON, D. J. MAWMAN, T. UPILE, R. T. RAMSDEN

TABLE IIRESULTS OF PRE-OPERATIVE LIP-READING WITH HEARING AID AND POST-OPERATIVE LIP-READING WITH ELECTRICAL STIMULATION

Patient1245678

ALR50767432626836

BKB

PI 9LR+ES

84989096989694

PI 18LR+ES

88—

100—

10098

ALR39.958.814.729.437.842.029.4

vcvPI 9

LR+ES65.1—

50.4—

96.679.8

PI 18LR+ES

60.9—

75.6—

84

ResultsAll patients had an uneventful post-operative

recovery. One myringoplasty patient (4) suffered asubsequent episode of otitis media in the implantedear, and this settled promptly on a short course ofantibiotics, without any adverse effects on the drumor the performance of the implant.

BKB, VCV and ES scores are available at ninemonths or earlier for seven out of the nine patientsand at 18 months for five of the nine. Patient 3 is achild and has not had the conventional adultassessments shown below. Patient 9 is not availablefor testing for geographical and linguistic reasons.Nevertheless one of the authors has heard herconverse easily in her own language with littlereliance on lip reading and she is very happy withthe result of her implantation.

BKB results with LR+ES were 80 per cent orbetter at nine months with a mean of 93 per cent (84per cent to 98 per cent). At 18 months, the meanLR+ES was 96.5 per cent (88 per cent to 100 percent). In every case there was an improvement in thescores between nine and 18 months (Table 2, Figure1). ES scores at nine months ranged from 0 per centto 94 per cent with a mean score of 52 per cent and at18 months ranged from 72 per cent to 88 per centwith a mean of 82.7 per cent (Table III).

VCV results with LR+ES at nine months rangedfrom 50.4 per cent to 96.6 per cent with a mean of 73

• ALR

• Post implant SLR +ES

D Post implant 18 Lfi+ES

FIG. 1Analyses of the change in accuracy of identification of wordsin sentences (BKB) comparing performance when lip-readingwas supplemented by a hearing aid pre-operatively (ALR)

and by implant post-operatively (LR+ES).

per cent. At 18 months, the mean LR+ES was 73.5per cent (60.9 per cent to 84 per cent) (Table II,Figure 2). ES scores at nine months ranged from 31.5per cent to 81.9 per cent with a mean score of 45.2per cent and at 18 months ranged from 25.2 per centto 67.2 per cent with a mean of 43.4 per cent (TableIII).

The mean ENV results at one month was 49.3 percent ranging from 37.5 per cent to 75 per cent. Atnine months, a mean score of 66.9 per cent rangingfrom 45 per cent to 85 per cent and at 18 months amean score of 58.3 per cent ranging from 42.5 percent to 77.5 per cent (Table III, Figure 3).

DiscussionCochlear implantation has been performed in a

series of nine patients with CSOM and profounddeafness. All of these patients have derived greatbenefit from the surgery, and it is quite clear to usthat they represent a group which though moredifficult to manage than the 'usual' cochlear implantpatient, should be seriously considered by the teamsengaged in this exciting field of work. Eachindividual should have his or her treatment indivi-dualized, but even so certain general observationscan be made. If a well-performed operation is to sealoff the middle ear, or obliterate the mastoid, thereseems to be little risk of rejection of the implant. Asimple dry perforation can be easily repaired andshould present no long-term problems. It has beenour practice to perform two-stage surgery in thissituation and to observe a soundly healed drum forthree months before proceeding to implantation. Noparticular technical problems need be expected atimplantation. Subsequent acute otitis media has notled to rejection although it would seem sensible totreat such infections vigorously.

Management becomes more complicated in thepresence of a previous mastoid cavity, be it healthyor infected, or if cholesteatoma is present in apreviously un-operated ear. The main issues concernthe questions of staging and of obliteration as well asthe actual techniques. Certainly in an ear withcholesteatoma present, a two-stage procedure isrecommended, with eradication of disease at thefirst operation followed by insertion of the implantsix months later if the ear is disease free. It is alsoessential to create a strong protective layer of tissuewith which to cover the implant. Simply to insert anelectrode under the epithelial lining of the mastoid is

COCHLEAR IMPLANTATION IN THE PRESENCE OF CHRONIC SUPPURATIVE OTITIS MEDIA 231

TABLE IIIRESULTS AT 1, 9 AND 18 months with electrical stimulation alone

Patient

1245678

PI9ES0

725038689458

BKBPI 18 ES

0

72

8888

PI9ES31.5—

31.5——

81.935.7

vcvPI 18 ES

25.2—

37.8—

—67.2

PI1 ES37.537.54550507550

ENV

"-PI9ES

45—

60——

8577.5

PI 18 ES

42.5—

55———

77.5

to court disaster and virtually guarantee rejection ofthe device as was found in Patient 8. Our techniquehas been to swing a pedicled flap of temporalismuscle into the mastoid and middle ear, and eitherto perform blind sac closure of the meatal skin, or tocover the muscle with the preserved lining of themastoid if it is healthy. If the mastoid and middle earare disease free and stable, the implant may beinserted at the same operation. If there is any doubtabout eradication of disease a two-stage proceduremust be performed. Elevation of the fibro-epitheliallining of the mastoid should be carried out meticu-lously whether it is to be preserved or discarded, toensure that no squamous epithelium is left behindand for the same reason the matsoid bone and anyremaining air cells should be drilled out. Quiteconsiderable drilling may be necessary in the regionof the upper edge of the mastoidectomy in order toprovide a smooth surface for the temporalis muscleflap. As in any revision mastoidectomy extra care isappropriate when elevating soft tissue off the facialnerve or its canal. If the operation is to be staged oneshould consider whether to insert a silastic sheetbetween the muscle flap and the promontory. It isnot necessary in the majority of cases, as no greatdifficulty is encountered dissecting the flap off thepromontory at the second-stage procedure. It is

• ALR

• Post-implant 9 months LR+ES

• Post-implant 18 months LR+ES

FIG. 2Analyses of the change in accuracy of identification of vowel-consonant-vowel syllables (VCV) comparing performancewhen lip-reading was supplemented by a hearing aid (ALR)

pre-operatively and by implant post-operatively (LR+ES).

advisable however if the facial nerve is dehiscent soas to prevent adhesions between the muscle flap andthe nerve.

One of the worries with obliteration operations isthe fear of entrapment of squamous epithelium outof sight and this remains a niggling anxiety in thesecases. It is a problem that is compounded by the factthat MR, which might allow one to monitordeveloping cholesteatoma is of no use in cochlearimplant patients, not only because of the presence ofthe magnet, but because of the signal void whichoccurs round implanted metal. The patients in thisseries have had no obvious recurrence and undergoclose clinical monitoring.

There are relatively few reports in the literature ofcochlear implantation in the presence of CSOM.Schlondorff et al. (1989) describe a technique ofimplantation in a mastoid cavity by which a fullthickness post-auricular skin flap was swung into themastoid bowl to protect the implant. Clark et al.(1995) described the implantation of three patientswith CSOM without cholesteatoma. All three hadrecurrence of their middle ear disease requiringfurther surgery. One patient developed infectionwithin the otic capsule via the cochleostomy and hadto have his implant removed. They concluded that ifimplantation was to be considered in the presence of

EJ Post-implant 1 month ES

• Post-implant 9 months ES

D Post-implant 18 months ES

FIG. 3Analyses of the change in accuracy of identification ofenvironmental sounds (ENV) by electrical stimulation (ES)comparing performance at 1, 9 and 18 months post-implant.

COCHLEAR IMPLANTATION IN THE PRESENCE OF CHRONIC SUPPURATIVE OTITIS MEDIA 231

TABLE IIIRESULTS AT 1, 9 AND 18 months with electrical stimulation alone

Patient

1245678

PI9ES0

725038689458

BKBPI 18 ES

0

72

8888

PI9ES31.5—

31.5——

81.935.7

vcvPI 18 ES

25.2—

37.8—

—67.2

PI1 ES37.537.54550507550

ENV

"-PI9ES

45—

60——

8577.5

PI 18 ES

42.5—

55———

77.5

to court disaster and virtually guarantee rejection ofthe device as was found in Patient 8. Our techniquehas been to swing a pedicled flap of temporalismuscle into the mastoid and middle ear, and eitherto perform blind sac closure of the meatal skin, or tocover the muscle with the preserved lining of themastoid if it is healthy. If the mastoid and middle earare disease free and stable, the implant may beinserted at the same operation. If there is any doubtabout eradication of disease a two-stage proceduremust be performed. Elevation of the fibro-epitheliallining of the mastoid should be carried out meticu-lously whether it is to be preserved or discarded, toensure that no squamous epithelium is left behindand for the same reason the matsoid bone and anyremaining air cells should be drilled out. Quiteconsiderable drilling may be necessary in the regionof the upper edge of the mastoidectomy in order toprovide a smooth surface for the temporalis muscleflap. As in any revision mastoidectomy extra care isappropriate when elevating soft tissue off the facialnerve or its canal. If the operation is to be staged oneshould consider whether to insert a silastic sheetbetween the muscle flap and the promontory. It isnot necessary in the majority of cases, as no greatdifficulty is encountered dissecting the flap off thepromontory at the second-stage procedure. It is

• ALR

• Post-implant 9 months LR+ES

• Post-implant 18 months LR+ES

FIG. 2Analyses of the change in accuracy of identification of vowel-consonant-vowel syllables (VCV) comparing performancewhen lip-reading was supplemented by a hearing aid (ALR)

pre-operatively and by implant post-operatively (LR+ES).

advisable however if the facial nerve is dehiscent soas to prevent adhesions between the muscle flap andthe nerve.

One of the worries with obliteration operations isthe fear of entrapment of squamous epithelium outof sight and this remains a niggling anxiety in thesecases. It is a problem that is compounded by the factthat MR, which might allow one to monitordeveloping cholesteatoma is of no use in cochlearimplant patients, not only because of the presence ofthe magnet, but because of the signal void whichoccurs round implanted metal. The patients in thisseries have had no obvious recurrence and undergoclose clinical monitoring.

There are relatively few reports in the literature ofcochlear implantation in the presence of CSOM.Schlondorff et al. (1989) describe a technique ofimplantation in a mastoid cavity by which a fullthickness post-auricular skin flap was swung into themastoid bowl to protect the implant. Clark et al.(1995) described the implantation of three patientswith CSOM without cholesteatoma. All three hadrecurrence of their middle ear disease requiringfurther surgery. One patient developed infectionwithin the otic capsule via the cochleostomy and hadto have his implant removed. They concluded that ifimplantation was to be considered in the presence of

EJ Post-implant 1 month ES

• Post-implant 9 months ES

D Post-implant 18 months ES

FIG. 3Analyses of the change in accuracy of identification ofenvironmental sounds (ENV) by electrical stimulation (ES)comparing performance at 1, 9 and 18 months post-implant.

232 P R. AXON, D. J. MAWMAN, T. UPILE, R. T. RAMSDEN

CSOM, a radical mastoidectomy with obliterationshould be considered. The possibility of infectionentering the inner ear through the cochleostomy hasbeen considered by Franz et al. (1987) and Jackler etal. (1986). Irving and Gray (1994) have adopted thisprinciple in cases of CSOM without cholesteatomawith a two-stage procedure three to six monthsapart.

Jackler, R. K., O'Donoghue, G. M., Schindler, R. A. (1986)Cochlear implantation: Strategies to protect the implantedcochlear from middle ear infection. Annals of Otology,Rhinology and Laryngology 95: 66-70.

Schlondorff, G., Hermes, H., Week, L. (1989) Cochlearimplants bei patientten mit radikalhohle. Head and Neck,Otolaryngology 37 (10): 423^25.

Summerfield, A. Q., Marshall, D. H. (1995) CochlearImplantation in the UK 1990-1994. Main report, report bythe MRC Institute of Hearing Research HMSO, London,UK pp 63-89.

ReferencesClarke, G. M., Pyman, B. C , Webb, R. L. (1995) Chronic

middle ear disease and cochlear implantation. Annals ofOtology, Rhinology and Laryngology (Suppl. 166): 406-408.

Franz, B. K. H., Aud, D., Clark, G. M. (1987) Effect ofexperimentally induced otitis media on cochlear implants.Annals of Otology, Rhinology and Laryngology 96:174-177.

Irving, R. M., Gray, R. F. (1994) Cochlear implants in chronicsuppurative otitis media: preparing the septic ear for asterile device. (Hochmair-Desoyer II, Hochmair ES, eds.)Advances in Cochlear Implants Vienna, Austria, Manz, pp223-227.

Address for correspondence:Mr P. R. Axon,1 Westgate,Hale,Altrincham WA15 9AY.

Fax: 0161 276 8511