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Table of Contents
ORIGINAL ARTICLE
Year : 2013  |  Volume : 15  |  Issue : 1  |  Page : 1-5

Cochlear implantation in patients with radical mastoid cavities


Department of Otorhinolaryngology, King Abdulaziz University Hospital, College of Medicine, King Saud University, Riyadh, Saudi Arabia

Date of Web Publication2-Jan-2020

Correspondence Address:
DIS (Fr.) MS (Eg.) Hazem Y Abdelwahed
Department of ORL,HNS, King Abdulaziz University Hospital, Riyadh 11411
Saudi Arabia
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1319-8491.274641

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  Abstract 


In the past, cochlear implantation was a contraindicated procedure in profoundly deaf patients with radical mastoid cavities. This was due to high risk of infection spread into the cochlea with possible destruction of the remainder surviving cochlear neural elements.
We report on King Abdulaziz University Hospital, Riyadh, Saudi Arabia experience in managing, two postlingual profoundly deaf patients (both male and adult) with radical mastoid cavities due to chronic cholesteatomatous otitis media by cochlear implantation. Two different open techniques were used, cochlear implantation with (in the first patient) and without (in the second patient) obliteration of the pre-existing mastoid cavity. One patient (first) suffered infection of mastoid cavity with extrusion of electrode, 55 months post-implantation. The infection could not be controlled without explantation, so the patient was explanted. The other (second) patient suffered facial nerve twitching, ear discharge and later failure of the implant as proved by integrity testing, 22 months post-implantation. The infection subsided after explantation. We recommend regular clinical and audiological follow-up of such patients in the same cochlear implantation center to avoid any complications which may lead to implant failure or electrode extrusion. This is also useful to discover and treat early any potential recurrent infection or cholesteatoma. High-resolution computed tomography scan of temporal bone is a good tool in the follow-up of patient with post-implantation complications or those implanted with closed blind sac technique which may be a better alternative technique than the open technique.

Keywords: Radical mastoid cavities, Bilateral profound sensorineural hearing loss, cochlear implantation, open technique


How to cite this article:
Attallah MS, Al-Muhaimeed HS, Abdelwahed HY. Cochlear implantation in patients with radical mastoid cavities. Saudi J Otorhinolaryngol Head Neck Surg 2013;15:1-5

How to cite this URL:
Attallah MS, Al-Muhaimeed HS, Abdelwahed HY. Cochlear implantation in patients with radical mastoid cavities. Saudi J Otorhinolaryngol Head Neck Surg [serial online] 2013 [cited 2022 Nov 28];15:1-5. Available from: https://www.sjohns.org/text.asp?2013/15/1/1/274641




  Introduction Top


Cochlear implantation is still the most word-wide effective procedure for the management of bilateral profound sensorineural hearing loss. Cochlear implantation is safe in profoundly deaf patients with normal ear anatomy.

In the past, cochlear implantation was a contraindicated procedure in profoundly deaf patients with radical mastoid cavities. This was due to high risk of infection spread into the cochlea through the implantation site with possible destruction of the remained surviving cochlear neural elements.

Cochlear implantation indications were extended due to surgical advances and development of implant technology to include the above mentioned patients, provided that their pre-existed mastoid cavities are stable and disease-free.

As mentioned by Hamzavi et al,(2001 (1), different complications have occurred in such cases.For example radical cavity infection, fat necrosis, skin flap problems, change in electrode position and cholesteatoma. Pasanisi et al,2002 (2), stated that many surgeons suggested overcoming these problems by performing an obliterative technique, whereas others preferred to maintain the benefits of an open technique or to rehabilitate the cavity. It has also been suggested that the cavity be bypassed via a middle cranial fossa approach.

This paper aims to report on King Abdulaziz University Hospital, Riyadh, Saudi Arabia, experience in managing by cochlear implantation two postlingual profoundly deaf patients (both male and adult) with past history of bilateral radical mastoid cavities due to chronic cholesteatomatous otitis media. We will discuss the surgical techniques and outcome.


  Materials and Methods Top


Records of cochlear implanted patients (total 135) in the Otolaryngology Department of King Abdulaziz University Hospital (College of Medicine, King Saud University, Riyadh, Saudi Arabia) between June 1995 and December 2008 were retrospectively reviewed.

Two postlingual profoundly deaf patients (both adult males) who underwent cochlear implantation in a radical cavity were identified. Both patients suffered long duration of bilateral chronic cholesteatomatous otitis media leading to severe hearing impairment. There was a past history of bilateral canal wall down mastoidectomy and hearing aid use which was initially useful. Despite abnormal anatomy of the ear, both patients met the implantation criteria.

Two different open techniques were used; cochlear implantation with ( in the first patient) and without ( in the 2nd patient) obliteration of the preexisting mastoid cavities. External auditory canal was preserved patent.

Surgery

Technique:

Both underwent right cochlear implantation with ( in the first patient) and without ( in the second patient) obliteration of the pre-existing radical mastoid cavity [Figure 1].
Figure 1: (A, B, C): revealed some steps of Cochlear implantation in the first patient with obliteration of the preexisted mastoid cavity. A: Complete insertion of the electrode. B & C: Obliteration of the pre-existed mastoid cavity.

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Widening and revision of the mastoid cavity was done. The bone, few centimeters behind the mastoid cavity was drilled to prepare a well for the implant and a groove in front to fit the electrode. Two small openings at the edge of the groove were made near the mastoid cavity edge for suturing, to help fixation of the electrode in place. Collected bone pate was used to fix the electrode in the distal portion of its groove and in the mastoid cavity. Cochleostomy was performed antero-inferior to the round window niche and the electrode array was fully inserted. Only in the first patient, the mastoid cavity was obliterated by collected bone pate (dust), a piece of conchal cartilage, and a piece of temporalis fascia. Small pieces of conchal cartilage were also used to cover the intertympanic part o f the electrode against the tympanic membrane. Only in the 2nd patient temporalis muscle was used alone to fix the electrode in the mastoid cavity which was not obliterated. Right myringoplasty using a piece of temporalis fascia was performed to close the previously existing anterior perforation. The external auditory canal was preserved in both patients.

For both patients, the intera-cochlear electrode array position was routinely assessed in the 1st postoperative day, using conventional radiology (trans-orbital view).

Intra-operative and post-operative programming of the implants was made using compatible hardware and software. Neural response telemetry was used for intra-operative assessment of the electrode function and post-operative mapping. Programming sessions were arranged according to each patient’s specific need. Minimal auditory capability test was used. Patients perception and discrimination of speech and sound were assessed by use of a protocol designed to meet the needs of the Arabic language.


  Results Top


Records of cochlear implanted patients (total 135) in the Otolaryngology Department of King Abdulaziz University Hospital (College of Medicine, King Saud University, Riyadh, Saudi Arabia) between June 1995 and December 2008 were retrospectively reviewed. Two postlingual profoundly deaf patients (both adult males) who underwent cochlear implantation in a radical cavity were identified. Demographic information is presented in [Table 1].
Table 1: Demographic information of cochlear implanted patients in pre-existed radical mastoid cavities.

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Pure tone audiogram measured before and a few months after implantation showed an improvement in free field tone threshold. Patients also showed improvement in speech and sound detection.

The 1st patient suffered infection of the mastoid cavity with the extrusion of the electrode 55 months postimplantation. The infection could not be controlled without explantation. Surgery revealed that the electrode was extruded and found free in the mastoid cavity.

The 2nd patient suffered facial nerve twitching, ear discharge and later failure of the implant as proved by integrity testing. 22 months post-implantation. The infection subsided after explanation. Surgery revealed that the electrode was cut at the Cochleostomy site and found directed towards the facial nerve possibly due to pre-explantation self ear cleaning or ear discharge suctioning attempt in a private clinic.


  Discussion Top


This current paper report on King Abdulaziz University Hospital, Riyadh, Saudi Arabia experience in managing, two postlingual profoundly deaf patients (both male and adult) with past history of bilateral radical mastoid cavities due to chronic cholesteatomatous otitis media, by cochlear implantation. Two different open techniques were used, cochlear implantation with (in the first patient) and without (in the second patient) obliteration of the pre-existing mastoid cavity by one stage surgery. In both patients, the external auditory canal was reserved patent.

One patient (first) suffered infection of mastoid cavity with extrusion of electrode, 55 months postimplantation. The infection could not be controlled without ex-plantation, so the patient was ex-planted. The surgery revealed that the electrode was extruded and freely found in mastoid cavity. The other (second), suffered facial nerve twitching, ear discharge and later failure of the implant as proved by integrity testing, 22 months post-implantation. The infection subsided after ex-plantation. Surgery revealed that the electrode was cut at cochleostomy site and found directed toward the facial nerve due to possible pre-ex-plantation self ear cleaning or ear discharge suction attempt in patient’s region private clinic.

Hamzavi et al (2001) (1) applied the same technique as ours ( in second patient cochlear implantation without obliterating the mastoid cavity) for a patient with a dermatological problem (mycosis fungoides). This subject experienced a retraction of the electrode by 15 mm 6 months after the operation. They re-operated on this patient (reinsertion of electrode to a depth of 30 mm) and operated on another 7 patients (cochlear implantation), using different obliterating technique performing obliteration of the radical cavity by abdominal fat covered with the temporal muscle flap, fixation of the electrode using muscle flaps at cochleostomy and bone pate at the posterior wall of the mastoid cavity. They also obliterated the Eustachian tube opening and blind sac closure of the external auditory canal. Pasanisi et al (2002) (2) also applied the closed sac technique in 6 postlingually deafened adults who received a cochlear implant in a radical cavity.

Compared with our results, no complications (except initially in their first patient) occurred in any of the subjects of Hamzavi et al (2001) (1) were reported with an observation interval of 9-30 months (mean 32 months). Pasanisi et al (2002) (2), reported no complications were observed with a follow-up ranging from 1 to 9 years. Mastoid cavity infection or ear discharge of our study patients may be due to a retrograde contamination via the Eustachian tube opening or the external auditory canal which were not obliterated. On the other hand, electrode extrusion or cut may be due to ear discharge or possible ear cleaning trial, respectively. Hamzavi et al (2001) (1) stated that extraction of the electrode from the scala tympani when attempting to clean the ear is a disadvantage of the non-obliterating procedure i.e. cochlear implantation without obliteration or reduction of the radical cavity. As mentioned by Hellingman and Dunnebier (2009) (3) a history of ear disease appears to significantly increase the risk of infection post-implantation. They added that the development of otitis media after implantation may cause intracranial complications or device extrusion wich may necessitate device removal.

In general, our results were comparable with that of Hamzavi et al (2001) (1) in their first patient only who initially underwent cochlear implantation with non-obliterative technique, followed by electrode retraction after an observation interval of 6 months. On the other hand, our results were not comparable with that of Hamzavi et al (2001) (1) in their other patients due to perhaps their shorter observation interval (9-30 months, mean 32 months) and their use of total obliterative technique (closed technique i.e. closed blind sac technique), while our study observation interval was 22 to 55 months and our used technique was open one (i.e. external auditory canal was preserved patent) with (in the first patient) and without (in the second patient) obliteration of the pre-existed mastoid cavity.

Pasanisi et al (2002) (2) stated that in patients who previously underwent radical surgery of the middle ear, one of the most common postoperative complications of cochlear implantation surgery is the extraction of the electrode array into the mastoid cavity/external auditory canal. This can be explained by Hellingman and Dunnebier (2009) (3) reporting that the thin epithelial lining of the mastoid cavity is nearly always insufficient to protect any kind of implanted foreign body itself and, therefore, simply inserting the electrode under the epithelial lining leaves it vulnerable to exposure. They added that it is possible to obliterate the cavity completely using abdominal fat, a pedicled temporalis muscle flap, or a combination of both and in case of total obliteration, the Eustachian tube is obliterated as well and the external ear canal is closed as a blind sac.

In spite of obliterating the radical cavity in the first patient of this current study, extrusion of implant electrode was lately encountered. This may be explained due to late mastoid cavity infection affecting the obliterating used materials (bone pate, piece of conchal cartilage and piece of temporalis fascia) or due to potential electrode looping with possible pressure necrosis and breakdown of the thin epithelial lining of the mastoid cavity. Manrique et al (1996) (4) reported cochlear implantation in a patient with a radical cavity and to protect the electrode array within the mastoid cavity, pieces of fascia and a flap of temporal muscle were used but within less than 6 months the electrode array had become exposed over the facial ridge which is comparable with our results. Hellingman and Dunnebier (2009) (3) stated that the most suitable material to obliterate the cavity appears to be abdominal fat because of its resistance to necrosis. According to Pasanisi et al (2002) (2), autologus abdominal fat can be considered the material of choice, for creating a healthy and strong protective layer to cover the implant, because of its easy availability, low metabolic rate, and resistance to necrosis.

A new surgical approach to avoid electrode looping was initially developed by Manrique et al in (1996)(4) and lately used by Karatzanis et al in (2003) (5) depends on the posterior placement of the device (about 25 mm behind the edge of the mastoid cavity) with drilling the groove for the electrode in a zigzag or wave-like fashion in the external table of the temporal bone so that the main length of the array lies outside the radical mastoidectomy cavity. Manrique et al (1996) (4) applied this technique on 5 adult patients, followed for 16 to 38 months and no patient has experienced otorrhea or local or intracranial complications, and all remain free of cholesteatoma. Also, Karatzanis et al (2003)(5) applied the same technique on an adult patient and no complications have been reported 6 years after the procedure.

Karatzanis et al (2003) (5) stated the advantages of the above mentioned technique. Firstly, the placement of the electrode array under the epithelial layer of the mastoid cavity is not time consuming, and it is relatively easily performed even by less experienced surgeons. Secondly, the mastoid cavity can be better visualized and cleaned during the post-operative follow-up period. Lastly, avoiding any obliterative technique around the facial recess, the possibility of cholesteatoma formation in the mastoid cavity is diminishing. On the other hand, Manrique et al (1996) (4) said “while the immediate anatomic and clinical results with our surgical technique have been satisfactory, follow-up over a longer period must be maintained to validate its efficacy. Two possible long-term complications could be the onset of new episode of otorrhea or the exposure of the implant”.

As demonstrated in this current study, ear discharge was a late complication which cannot be completely controlled except after explantation. It happened earlier in our second patient who underwent a one-stage cochlear implantation without obliteration of the mastoid cavity and myringoplasty. Hellingman and Dunnebier (2009) (3) reported that it should be born in mind that closure of the perforation, to protect the electrode array in the middle ear, might reactivate the chronic suppurative otitis media. This makes it inadvisable, even if the perforation is small, to perform myringoplasty and cochlear implantation at the same time. They added “therefore, in patients with a dry tympanic membrane perforation, repair of the perforation and cochlear implantation in a staged procedure appears to be the best solution”.

Pasanisi et al (2002) (2) mentioned that most surgeons recommend obliteration and isolation of the cavity from the outer environment by a blind sac closure of the external auditory canal and obliteration of the Eustachian tube opening. In addition, the obliterative techniques improve the quality of life of patients because they offer the advantage of an ear that commonly does not need lifelong care. We also think that total obliterative closed technique i.e. blind closed sac technique may be a better alternative technique to avoid our encountered complications or risk of inner ear infection. Karatzanis et al (2003) (5) agree with us and stated that potentially a closed technique would theoretically provide better protection from an inner ear infection and its complications. They added that this technique would carry a high risk of cholesteatoma recurrence, and, therefore, early recognition and management of such a condition would be quite difficult.

Hellingman and Dunnebier (2009) (3) disagree with us and stated that non-obliterative technique i.e. open technique with or without partial obliteration of the mastoid cavity seem to be a safe alternative for obliterative surgery in cochlear implantation, without the complicated radiologic diagnosis of cholesteatoma that is a consequence of obliteration.

Whatever technique used in such cases, we recommend regular clinical and audiological follow-up of these patients in the same cochlear implantation center to avoid any complications which may lead to implant failure or electrode extrusion. This is also useful to discover and treat early any potential recurrent infection or cholesteatoma. High-resolution computed tomography scan of the temporal bone is a good tool in the follow-up of patient with post-implantation complications or those implanted with closed blind sac technique which may be a better alternative technique than the open technique.



 
  References Top

1.
Hamzavi J, Baumgartner W, Franz P, Plenk H. Radical cavities and cochlear implantation. Acta Otolaryngol. 2001; 121(5):607-9.  Back to cited text no. 1
    
2.
Pasanisi E, Vincent V, Bacciu A, Guida M, Berghenti T, Barbot A, Zini C, Bacciu S. Multichannel cochlear implantationin in radical mastoidectomy cavities. Otolaryngol Head Neck Surg.2002; 27(5):432-6.  Back to cited text no. 2
    
3.
Hellingman CA, Dunnebier EA.Cochlear implantation in patients with acute or chronic middle ear infectious disease: a review of the literature. Eur Arch Otorhinolaryngol. 2009; 266(2):171-6.  Back to cited text no. 3
    
4.
Manrique M, Cervera-Paz FJ, Espinosa JM, Perez N, Garcia-Tapia R. Cochlear implantation in radical cavities of mastoidectomy. Laryngoscope. 1996; 106(12 Pt 1):1562-5.  Back to cited text no. 4
    
5.
Karatzanis AD, Chimona TS, Prokopakis EP, Kyrmizakis DE, Velegrakis GA. Cochlear implantation after radical mastoidectomy: management of a challenging case. ORL J Otorhinlaryngol Relat Sepc. 2003; 65(6): 375-8.  Back to cited text no. 5
    


    Figures

  [Figure 1]
 
 
    Tables

  [Table 1]


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