Long-term complications after cochlear implantation

Objective

Cochlear implantation has become an effective treatment for many profoundly deaf patients. As with any surgical procedure, a proportion of patients suffer postoperative complications. The aim of this study was to analyze long-term postoperative complications in patients with cochlear implants with a view to improve clinical interventions and propose a consensus for reporting complications.

Methods

A total of 406 cases received cochlear implants between December 1985 and April 2007 at Tokyo Medical University (TMU) Hospital. We retrospectively reviewed case notes from 366 patients who had undergone cochlear implantation (215 adults and 151 children) after excluding 40 patients of re-implantation including 13 cases implanted initially at other hospitals. Life-threatening, major and minor complications were examined retrospectively.

Results

Major complications occurred following cochlear implantation in 32 patients (8.7%) who had received their initial implant at TMU Hospital. Revision surgery was required for 30 patients. The mean age at implantation was 33 years 6 months (range, 1 year 9 months to 83 years; median, 37 years). The main etiology of deafness was unknown or progressive (113, 52.6%) in adults and congenital (132, 87.4%) in children. The cause of deafness was meningitis in 41 cases (11.2%), and 26 cases (7.1%) were diagnosed with idiopathic sudden deafness.Flap-related problems (including middle ear infection and/or flap necrosis) developed in 13 cases (3.6%), with 12 cases (7 adults, 5 children) requiring re-implantation. Electrode slip-out occurred in 8 patients (7 adults, 1 child). All adult cases in whom electrodes slipped out underwent implantation before 1994, while the child (1 pediatric case) was operated in 2003. All cases required re-implantation and most cochlear implantations were performed using the modified split-bridge technique after 1997. Six patients (4 adults, 2 children) experienced device failure. Four patients experienced electrode problems. Non-surgical major complications included 1 patient with permanent facial nerve paralysis as a result of thermal injury in 1995.The total number of minor medical and surgical complications was 27, representing 7.4% of all operations.

Conclusion

Many cases of major complications, including electrode problems and facial paralysis, excluding traumatic device failure were considered avoidable by strict operative and postoperative procedures. Some cases of flap infection and traumatic device failure may not be able to be avoided completely, and every possible care should be taken by implant patients and others involved.     

Complications and clinical analysis of 416 consecutive cochlear implantations

Objectives

Cochlear implantation is a safe technique with a relatively low complication rate. However, certain complications may require specific attention to treat. The purpose of this study was to investigate complications of cochlear implantation for prevention and therapy.

Study design

Retrospective case series at a tertiary referral center in China.

Methods

The patients (n = 416) who received cochlear implants in our department between 2000 and 2010 were followed up (range, 3 months to 10 years). The complications were identified as “minor” or “major”. All complications were systematically reviewed, and their causes were analyzed for prevention and therapy.

Results

There were a total of 29 complications (7%). The minor were 23 cases (5.5%), including postoperative subcutaneous hematoma in 13 cases, acute otitis media in 2 cases, postoperative wound infection in 2 cases, delayed facial paralysis in 1 case, clonic facial spasm in 1 case, and severe vertigo in 4 cases. The major were 6 cases (1.5%), including cerebrospinal fluid leakage in 2 cases, implant-related infection and extrusion in 1 case, tympanic membrane perforation induced electrode exposed in 1 case, implantation failure due to cochlear ossification in 1 case, and magnet displacement in 1 case.

Conclusions

Although cochlear implantation is popular, it is essential to decrease the incidence of complications.     

Simultaneous translabyrinthine removal of acoustic neuroma and cochlear implantation

Objectives

To report of a 65-year-old woman with bilateral Meniere's disease was referred for cochlear implantation (CI) due to severe/profound sensorineural hearing loss.

Methods

During the assessment workup, a vestibular schwannoma in the right ear was found by MR imaging. She underwent a translabyrinthine removal of the acoustic neuroma (AN) with sparing of the cochlear nerve and concurrent ipsilateral CI with a Nucleus Freedom device (Cochlear Ltd., Lane Cove, New South Wales, Australia).

Results

Complete removal of the AN was achieved without complications. Neural Response Telemetry (NRT) measurements, which showed poor morphology at the intraoperative tests, rapidly improved after activation, similarly to electrically evoked auditory brainstem responses (E-ABR). The patient reached 100% speech perception performances within 2 months from implantation, in the monaural condition. She was relieved from vertigo spell up to 14 months after the operation.

Conclusion

Cochlear implantation at the time of acoustic neuroma removal with VIII nerve sparing can be a safe and effective hearing restoration procedure.     

HRCT and MRI findings in X-linked non-syndromic deafness patients with a POU3F4 mutation

Objective

The aim of this study was to analyze HRCT and MRI findings in patients with X-linked non-syndromic deafness and a POU3f4 mutation.

Methods

HRCT and MRI data of four patients (males, 2–19 years old) with a POU3f4 mutation were collected and a retrospective review was performed. Cochlea, internal auditory canal (IAC), vestibule, semicircular canals, vestibular aqueduct, nerve canals in the IAC fundus, stapes and cochlear nerve were evaluated on 2D images (multi-planner reformation, MPR) and cochlear foramen on 3D images (CT virtual endoscopy, CTVE). Ten cases with normal hearing subjected to CT and MR exams served as controls.

Results

Inner ear malformations were bilateral and symmetrical. Cochlear malformation was shown to consist of as a relatively normal outer coat shape, absence of a cochlear modilous, and a direct intercommunication between the IAC and cochlear inner cavity. The lateral portion of the IAC was dilated. A spiral cochlear inner cavity was observed with CTVE images versus a helical cochlear nerve foramen as seen in controls. The labyrinthine facial nerve canal and superior vestibular nerve canal were enlarged. The Bill's bar was hypertrophic and partially pneumatized. A thickened stapes footplate was present and a fissura ante fenestram was absent in seven ears examined. A column shaped stapes was observed in one ear.

Conclusions

The absence of a cochlear modilous with a dilated lateral IAC and thickened stapes footplate were the remarkable features observed with imaging these in X-linked non-syndromic deafness patients with a POU3F4 mutation. Preoperative recognition of the image features in these patients is important because it precludes stapedectomy and indicates the risks in the surgery of cochlear implantation including CSF gusher and electrode insertion into IAC.     

A new cochlear implant electrode with a “cork”-type stopper for inner ear malformations

Objective

Gusher in inner ear malformations is common in patients with incomplete partition type I and type III. It is also common in less severe form as oozing in incomplete partition type II and large vestibular aqueduct. It is important to prevent cerebrospinal fluid (CSF) escape around the electrode to prevent meningitis.

Methods

The custom-made device was produced by Med-El Company. It has a “cork”-like stopper instead of the usual silicon ring to prevent gusher. There are two types of electrodes of different lengths. The standard one is 25 mm (contact space 1.7 mm) and the short one is 20 mm (contact space 1.3 mm). It was used in 50 patients with different inner ear malformations.

Results

Thirteen patients had gusher, and 11 patients oozing during cochleostomy. One patient with initial prototype of the cork electrode had to be revised because of persistent oozing around the electrode. Another patient had slow extrusion of the electrode most probably due to CSF pulsation and had to be revised. Both patients had no more CSF fistula.

Conclusion

CSF fistula in inner ear malformations is a serious situation which may lead to recurrent meningitis. The new electrode with “cork” stopper looks promising in preventing the postoperative CSF leak around the electrode.     

Inner ear anatomy in Waardenburg syndrome: Radiological assessment and comparison with normative data

Objective

As patients with Waardenburg syndrome (WS) represent potential candidates for cochlear implantation, their inner ear anatomy is of high significance. There is an ongoing debate whether WS is related to any inner ear dysplasias. Our objective was to evaluate radiologically the inner ear anatomy in patients with WS and identify any temporal bone malformations.

Methods

A retrospective case review was carried out in a tertiary, referral center. The high resolution computed tomography (HRCT) scans of the temporal bone from 20 patients (40 ears) with WS who were managed for deafness in a tertiary referral center from 1995 to 2012 were retrospectively examined. Measurements of 15 different inner ear dimensions, involving the cochlea, the vestibule, the semicircular canals and the internal auditory meatus, as well as measurements of the vestibular aqueduct, were performed independently by two neuroradiologists. Finally, we compared the results from the WS group with a control group consisting of 50 normal hearing subjects (100 ears) and with previously reported normative values.

Results

Inner ear malformations were not found in any of the patients with WS. All measured inner ear dimensions were within the normative values compiled by our study group as well as by others.

Conclusions

Inner ear malformations are not characteristic for all types of WS; however, certain rare subtypes might be related to inner ear deformities. Normative cochleovestibular dimensions that can help in assessing the temporal bone anatomy are provided.     

Cochlear implantation in patients with chronic otitis media

Objective

Patients with complications of otitis media present a significant challenge to safe cochlear implantation. We describe our experience of cochlear implantation in patients with chronic ear disease, and propose management principles according to the presenting status of the ear.

Methods

Cochlear implantations were performed as treatment for complications of otitis media in seven patients. They consisted of four patients with adhesive otitis media, two patients with an open cavity after surgery for otitis media and one patient with eosinophilic otitis media.The electrodes were inserted by an approach via the external auditory canal in patients with poor growth of the mastoid antrum or adhesion of the tympanum. For the patients with an open cavity, we created a posterior wall for the external auditory canal and perform the mastoid obliteration. Modified Rambo's technique with blind sac closure of the external auditory canal was performed for the case of eosinophilic otitis media as a single-stage procedure.

Results

The post-operative courses were good. However, a post-operative infection developed in one patient who had previously undergone radiation therapy following surgical excision of a cerebellar tumor.

Conclusion

Transcanal approach is effective in a poorly pneumatized mastoid or severe adhesive otitis media.A decision whether implantation as a single-stage or multiple stages depends on the condition of each cases. But there is a possibility of infection even if we selected a stage operation.     

Minimizing the dead ear in otosclerosis surgery

Objective

Assessment of a specific surgical technique regarding the postoperative hearing results and the incidence of “dead ear” comparing local and general anesthesia.

Methods

We present a retrospective review of all stapedectomies performed by the same surgeon under general and local anesthesia during a 9-year period (1997–2006) in non-revision cases. The analysis of our data (268 operations, 160 under general and 108 under local anesthesia) included hearing results based on the guidelines from the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery and complications recorded in the case notes. Excessive vertigo during stapedectomy under local anesthesia considered as a sign of possible profound sensorineural hearing loss.

Results

A postoperative air-bone gap up to 10 dB (Grade A) was successfully obtained in 92.6% of operated ears. The mean postoperative air-bone gap in decibels was 6.8 dB. There were no statistically significant differences between general and local anesthesia in hearing results. Excessive intraoperative dizziness occurred in five patients of local anesthesia group without postoperative sensorineural hearing loss. The incidence of dead ear was 1.8 % (three patients) under general and 0% under local anesthesia.

Conclusion

Stapedectomy is a safe procedure in hands of an experienced otologist with minimum major complications especially when performed under local anesthesia. Local anesthesia offers the immediate evaluation of hearing restoration and the early recognition of possible dead ear. Training programs should consider stapedectomy under local anesthesia as a standard procedure for trainees in non-revision cases.     

Cochlear implantation in 13q deletion syndrome

Purpose

The advent of cochlear implantation has been followed by an explosion in surgical and technological advances with subsequent alterations in the treatment of sensorineural hearing loss management. Many individuals with rare genetic abnormalities who once may have not been considered candidates for cochlear implantation are now benefiting from cochlear implantation. One of these unusual syndromes is the 13q deletion syndrome. The clinical features of 13q deletion syndrome, a rare chromosomal abnormality, were originally described in the early 1960s, though the literature currently lacks defined phenotypic abnormalities. Patients with 13q deletion syndrome present with varying degrees of cognitive and growth delay, craniofacial dysmorphisms, and congenital malformations. The etiology of the sensorineural hearing loss has not been elucidated, and genes associated with other syndromes which include sensorineural hearing loss have been proposed as the causative agents. We describe the unique clinical and surgical considerations for 13q deletion syndrome and review the considerations when deliberating on cochlear implantation in syndromic hearing loss.

Materials and Methods

Case report.

Results

Successful cochlear implantation in a patient with 13q deletion syndrome.

Conclusion

Many patients with 13q deletion syndrome suffer from sensorineural hearing loss, and when appropriately selected may likely benefit from cochlear implantation. Many other syndromic patients following careful selection may also benefit from cochlear implantation and should not be excluded from consideration until appropriately evaluated.     

Incomplete partition type III: A rare and difficult cochlear implant surgical indication

Objective

Presenting the clinical features and treatment options for incomplete partition type-III.

Hearing restoration in NF2 patients and patients with vestibular schwannoma in the only hearing ear: report of two cases

Objective

To explore audiologic outcome of auditory brain stem implantation (ABI) and cochlear implantation (CI) in NF2 patients and patients with vestibular schwannoma (VS) in the only hearing ear.

Patients and methods

Study includes retrospective analysis of 2 cases. One is totally deaf patient due to NF2, and the other one is totally deaf due to VS development in only hearing ear. Tumor was removed by retrosigmoid approach in NF2 patient and ABI was performed simultaneously. For the VS in only hearing ear case, tumor was removed by translabyrinthine approach and CI was performed simultaneously.

Results

ABI patient showed quite well outcome during the 15 months of follow-up. She has 25 dB hearing threshold at speaking frequencies. She developed open set speech discrimination with 87.5% word discrimination score, and 70% sentence discrimination score. She uses device daily manner, she can use telephone. For CI patient, outcome is not perfect but satisfactory. She couldn’t develop open set speech discrimination during the 18 months of follow-up. She has 67% the disyllabic words recognition score (close set). She is daily user of device. CI improves quite well lip reading.

Conclusion

ABI and CI are the two options to restore hearing in VS caused deafness. We advocate giving every effort to preserve cochlear nerve during the VS resection and place CI simultaneously. However if it is not possible to preserve cochlear nerve during surgery, ABI is also a good alternative for hearing restoration.     

Vestibular evoked myogenic potentials in children after cochlear implantation

Objective

The aim of this study was to report the effect of unilateral cochlear implantation to vestibular system using vestibular evoked myogenic potentials (VEMPs) by air-conduction in a sample of children aged less than 5 years.

Materials

This study consisted of 10 children (6 boys and 4 girls), who underwent cochlear implantation surgery at our clinic, and 8 normal hearing children (5 boys and 3 girls) matched for age. The VEMPs were performed before, 10 days, and 6 months after surgery. Both the implanted and unimplanted ears of each child were evaluated, with the cochlear implant both off and on.

Results

Preoperatively, six (60%) children had abnormal VEMPs responses on both ears. In the postoperative sessions, no child showed any VEMPs response on the implanted side. The VEMPs were not recorded on the unimplanted side either, except for one case. At 6 months, the VEMPs response on the unimplanted side of three children became normal when the cochlear implant was on, and in two children with the device off.

Conclusion

In the postoperative 6-month-period, the disappearance of VEMPs suggests that the saccule of children can be extensively damaged following cochlear implantation. A recovery of VEMPs can take place on the unimplanted side, with the cochlear implant both on and off. Despite this saccular injury, the absence of clinical signs in children could be explained by their ability to effectively compensate for such vestibular deficits.     

Epicutaneous patch test—A new diagnostic option to prevent the rejection of silicone-covered cochlear implants in children

Objectives

Cochlear implantation (CI) is a revolutionary method for hearing rehabilitation in patients with severe or profound sensorineural hearing loss. One of the surgical complications may be the necrosis of the skin flap above the receiver-stimulator coil, resulting in device extrusion. Our aim was to find the plausible causes of the silicone covered implant rejection.

Patients and methods

Authors present four cases of cochlear implant rejection, briefly describe their dermato-surgical solutions and analyse their innovative method – the epicutanoeus patch testing with silicone samples.

Results

They observed positive skin reaction in three of the four cases.

Conclusion

Authors analyse the applicability and results of their surgical solutions and the epicutaneous testing in connection with the prevention of skin flap necrosis and rejection of silicone-covered cochlear implants.     

Revision surgeries and medical interventions in young cochlear implant recipients

Objective

To report devices failures and postoperative or medical complications after cochlear implantation in children and to discuss revision surgeries and medical interventions occurring during follow-up.

Methods

In this retrospective study in a tertiary referral pediatric hospital, we included a consecutive sample of children younger than 15 years old who received implants between January 1994 and June 2010. All complications and treatments were systematically reviewed.

Results

One hundred and forty children were included in this study. Four children received bilateral cochlear implantation. Mean age at implantation was 43.6 months (age ranged from 11 months to 15 years). Overall, 74 children were boys (52.1%) and 35 children (25%) received implants before the age of two. Inner ear malformations were found in 19 children (13.5%), while 18 children (12.9%) experienced complications: cochlear reimplantations (n = 8), other revision surgeries (n = 3) and medical treatment (n = 7). Excluding device failures, 13 children (9.2%) experienced complications. Postoperative infection was the principal cause of these complications (10 cases). Four children younger than 2 years at implantation suffered complication postoperatively. In these children, there was no statistically significant increase in complications compared to older children (P > 0.05). Complete electrode insertion was achieved in 7 of the 8 reimplanted children.

Conclusion

Cochlear implantation could be considered a safe and reliable rehabilitation for deafened young children. Reimplantation was feasible and complete electrode insertion was achievable. Long-term follow up was mandatory to minimize and control surgical complication.     

Cochlear implantation in children with cochlear nerve deficiency

Objective

The aim of this study was to report on auditory performance after cochlear implantation in children with cochlear nerve deficiency.

Methods

A retrospective case review was performed. Five patients with pre-lingual profound sensorineural hearing loss implanted in an ear with cochlear nerve deficiency participated in the study. Postoperative auditory and speech performance was assessed using warble tone average threshold with cochlear implant, speech perception categories, and speech intelligibility ratings. All patients underwent high resolution computed tomography and magnetic resonance imaging.

Results

According to Govaerts classification, three children had a type IIb and two a type IIa cochlear nerve deficiency. Preoperatively, four patients were placed into speech perception category 1 and one into category 2. All patients had an improvement in hearing threshold with the cochlear implant. Despite this, at the last follow-up (range 18–81 months, average 45 months), only one girl benefited from cochlear implantation; she moved from speech perception category 2 to 6 and developed spoken language. Another child developed closed set speech perception and had connected speech that was unintelligible. The other 3 children showed little benefit from the cochlear implant and obtained only an improved access to environmental sounds and improved lipreading skills. None of these 4 children developed a spoken language, but they were all full-time users of their implants.

Conclusions

The outcomes of cochlear implantation in these five children with cochlear nerve deficiency are extremely variable, ranging from sporadic cases in which open set speech perception and acquisition of a spoken language are achieved, to most cases in which only an improved access to environmental sound develops. Regardless of these limited outcomes, all patients in our series use their device on a daily basis and derive benefits in everyday life. In our opinion, cochlear implantation can be a viable option in children with cochlear nerve deficiency, but careful counseling to the family on possible restricted benefit is needed.     

Mastoid pressure dressing for cochlear implantation—Is it necessary?

Objectives

Mastoid pressure dressing (MPD) with circumferential head bandage after middle ear surgery and cochlear implantation (CI) is used to minimize the postoperative hematoma and thus provides a good wound covering. But such dressing is usually uncomfortable for patients and may lead to other unpredictable complications. This study was aimed to evaluate the need for MPD following CI.

Methods

Retrospective chart analysis of 92 consecutive patients who underwent CI.

Results

The 92 patients had a median age of 4.3 years. All patients were categorized into those receiving either MPD or simple gauze dressing (SGD). Six MPD patients and five SGD patients had minor surgical-site complications (9.1% and 6.3%, respectively), a statistically insignificant difference. The key to preventing hematomas is careful tissue handling and minimally invasive techniques. MPD alone rarely provides enough pressure to prevent hematoma.

Conclusions

This study found no clinically significant benefits for use of MPD following CI. We suggest abandoning the use of compression bandages after uncomplicated CI.     

Tinnitus after cochlear implantation

Objective

The purpose of this study was to investigate properties of tinnitus which starts after cochlear implantation. Of the 17 adult patients in our cochlear implant group, four (23.5%) who had no pre-implantation tinnitus were eligible for the study.

Methods

Each patient was requested to complete a short questionnaire regarding his or her experience with tinnitus. Tinnitus match test was performed for each patient by using an Interacoustic Clinical Audiometer (model AC40; Assens, Denmark).

Results

Tinnitus match test revealed a tinnitus frequency of a 4 KHz for three and of a 6 KHz for one patient. Mean value of the loudness score was calculated as 17.5 dB SL.

Conclusions

The results of this study emphasize the importance of counseling patients regarding risks of tinnitus after cochlear implantation.     

Pediatric cochlear implant revision surgery and reimplantation: An analysis of 957 cases

Objective

In this study causes, risk factors, prevention strategies, diffuculties encountered during revision cochlear implant surgery, reimplantation in pediatric age group were evaluated.

Methods

Charts of 957 CI patients younger than 18 years of age implanted at Izmir Bozyaka Teaching and Research Hospital between 1998 and July 2012 and 18 referred CI complications at same age group were retrospectively evaluated. Revision and reimplantation surgeries were systematically reviewed.

Results

We encountered 26 surgical complications in 24 patients and 36 device related problems in 36 patients. Eighteen referred cases including 7 surgical complications and 11 device related problems were also evaluated. A total number of 80 complications were evaluated. In 11 cases conservative management was successful, 19 revision surgery was performed but we failed in 4 cases. We reimplanted 48 cases and 4 additional cases were implanted after failed revision surgery. Implant was extracted in one case. In one case we could implant the other side. Forty-six of reimplantations were done in one stage surgery, 5 cases required second stage surgery.

Conclusions

Surgical complications and device related problems of cochlear implantation may be different in children and majority of them require revision surgery or reimplantation. Although surgical problems leading to revision surgery and reimplantation are expected to diminish by experience every center has to deal with device failures. Both revision surgery and reimplantation require extra care and it should be better carried out by experienced surgeons. Implant performances are expected to be comparable with primary implantations.     

A middle ear implant with a titanium canal wall prosthesis for a case of an open mastoid cavity

Objective

Open mastoid cavity rehabilitation should focus on both anatomical and functional aspects. We hereby report the technique and results of a combined strategy to reconstruct the external ear canal using a titanium wall implant and the middle ear using a fully implantable active middle ear device.

Methods

A fully implantable active middle ear implant was used to rehabilitate the mixed hearing loss of a 63-year-old woman, and a titanium posterior canal wall prosthesis was used to reconstruct the external ear canal during the same procedure. The middle ear implant was placed directly on the footplate. The auditory results were compared to the preoperative unaided thresholds and to the amplification of a conventional hearing aid.

Results

Following the procedure, there was an anatomically normal external ear canal with a healed tympanic membrane separating the external from the middle ear spaces. The postoperative auditory gains were on average 31.8 dB on pure-tone audiometry, and 20 dB on speech reception threshold. No complications occurred.

Conclusion

The rehabilitation of the external ear canal in an open mastoid cavity allows for clinical follow-up of the patient, and the implantation of an active middle ear implant provides appropriate auditory gains both in pure tones and in speech reception thresholds.