Minimally Traumatic Cochlear Implant Surgery: Expert Opinion in 2010 and 2020

This study aimed to discover expert opinion on the surgical techniques and materials most likely to achieve maximum postoperative residual hearing preservation in cochlear implant (CI) surgery and to determine how these opinions have changed since 2010. A previously published questionnaire used in a study published in 2010 was adapted and expanded. The questionnaire was distributed to an international group of experienced CI surgeons. Present results were compared, via descriptive statistics, to those from the 2010 survey. Eighteen surgeons completed the questionnaire. Respondents clearly favored the following: round window insertion, slow array insertion, and the peri- and postoperative use of systematic antibiotics. Insertion depth was regarded as important, and electrode arrays less likely to induce trauma were preferred. The usefulness of dedicated soft-surgery training was also recognized. A lack of agreement was found on whether the middle ear cavity should be flushed with a non-aminoglycoside antibiotic solution or whether a sheath or insertion tube should be used to avoid contaminating the array with blood or bone dust. In conclusion, this paper demonstrates how beliefs about CI soft surgery have changed since 2010 and shows areas of current consensus and disagreement.

Worldwide Variation in Cochlear Implant Candidacy

BACKGROUND

The aim of this study was to find out how candidacy criteria have evolved differently across the globe.

METHODS

Candidacy criteria and outcome measurements applied in 19 HEARRING clinics were analyzed.

RESULTS

Candidacy criteria vary between clinics. Overall, both bilateral implantation and cochlear implantation in patients with single-sided deafness are becoming more frequent.

CONCLUSION

Standardized outcome measurement instruments need to be applied to provide access to the hearing world to all patients with hearing loss who would benefit from cochlear implantation.

Two-phase survey on the frequency of use and safety of MRI for hearing implant recipients

PURPOSE

Magnetic resonance imaging (MRI) is often used to visualize and diagnose soft tissues. Hearing implant (HI) recipients are likely to require at least one MRI scan during their lifetime. However, the MRI scanner can interact with the implant magnet, resulting in complications for the HI recipient. This survey, which was conducted in two phases, aimed to evaluate the safety and performance of MRI scans for individuals with a HI manufactured by MED-EL (MED-EL GmbH, Innsbruck, Austria).

METHODS

A survey was developed and distributed in two phases to HEARRING clinics to obtain information about the use of MRI for recipients of MED-EL devices. Phase 1 focused on how often MRI is used in diagnostic imaging of the head region of the cochlear implant (CI) recipients. Phase 2 collected safety information about MRI scans performed on HI recipients.

RESULTS

106 of the 126 MRI scans reported in this survey were performed at a field strength of 1.5 T, on HI recipients who wore the SYNCHRONY CI or SYNCHRONY ABI. The head and spine were the most frequently imaged regions. 123 of the 126 scans were performed without any complications; two HI recipients experienced discomfort/pain. One recipient required reimplantation after an MRI was performed using a scanner that had not been approved for that implant. There was only one case that required surgical removal of the implant to reduce the imaging artefact.

CONCLUSION

Individuals with either a SYNCHRONY CI or SYNCHRONY ABI from MED-EL can safely undergo a 1.5 T MRI when it is performed according to the manufacturer's safety policies and procedures.

Inside implant criteria or not? - Detection of non-organic hearing loss during cochlear implant assessment

OBJECTIVES

The diagnosis of non-organic hearing loss (NOHL) is a difficult but important issue during the assessment process for cochlear implantation (CI). We aim to identify the key factors in identifying patients with NOHL during CI assessment and present our local screening protocol for NOHL.

METHODS

A retrospective review of patients referred to the Yorkshire Auditory Implant Service (YAIS) between 2003 and 2015 who were subsequently diagnosed with NOHL during the assessment. Patient demographic data, audiological and functional assessments were assessed.

RESULTS

Thirty-two patients were included in the study. Mean age was 43 years (range 14-82 years). Male to female ratio was 1:1.7. Indicators of possible NOHL included a sudden deterioration in hearing (n = 21; 66%), mismatches in observed behaviour and either pure-tone audiogram (PTA) (n = 27; 84%) or functional testing (n = 20; 80%) and stapedial reflexes below reported audiological thresholds (n = 12; 46%). A mismatch in functional hearing and PTA was seen in 72% of patients. Patients with suspected NOHL were referred for further objective testing. All 23 patients who underwent objective testing had better hearing levels compared to reported hearing thresholds thus placing them outside of implant criteria. Five candidates were found to have normal hearing thresholds.

DISCUSSION

NOHL can present a significant challenge to the implant team, particularly in the subgroup with a pre-existing organic hearing loss with non-organic overlay. We discuss the common features in this cohort of patients.

CONCLUSIONS

To facilitate the identification of patients with NOHL, the YAIS has developed a screening protocol.

Patient management for cochlear implant recipients in audiology departments: A practice review

OBJECTIVES

To determine and evaluate the time clinics needed to complete the sub-processes involved in the first-fitting and follow-up fitting of people with a cochlear implant.

METHODS

Eight HEARRING clinics completed a questionnaire recording how long it took to complete the sub-processes involved in first-fitting and follow-up fitting cochlear implant recipients. The mean times of clinics and procedures were then compared.

RESULTS

Questionnaires on 77 patients were completed. Clinics varied widely on time spent on each sub-process in both first- and follow-up fittings. Total first-fitting times were similar across clinics. Follow-up fitting times varied more across clinics although this may have been due to differences in questionnaire interpretation.

DISCUSSION

If a patient management plan can help increasingly busy cochlear implant clinics provide high-quality care more efficiently, essential first steps are determining which procedures are generally performed and how long their performance takes. Until reliable data are gathered, constructing a patient management plan or reaping the potential benefits of its use will remain elusive; clinics will have to find what solutions they can to meet rising workload demands.

CONCLUSION

The variation in time spent on each sub-process may suggest that some clinics have more efficient workflow procedures. Compiling a best practice for each process could be instrumental in creating a professional process management plan that would increase efficiency without sacrificing quality of care.

The effect of early auditory experience on the spatial listening skills of children with bilateral cochlear implants

OBJECTIVES

Both electrophysiological and behavioural studies suggest that auditory deprivation during the first months and years of life can impair listening skills. Electrophysiological studies indicate that 3½ years may be a critical age for the development of symmetrical cortical responses in children using bilateral cochlear implants. This study aimed to examine the effect of auditory experience during the first 3½ years of life on the behavioural spatial listening abilities of children using bilateral cochlear implants, with reference to normally hearing children. Data collected during research and routine clinical testing were pooled to compare the listening skills of children with bilateral cochlear implants and different periods of auditory deprivation.

METHODS

Children aged 4-17 years with bilateral cochlear implants were classified into three groups. Children born profoundly deaf were in the congenital early bilateral group (received bilateral cochlear implants aged ≤3½ years, n=28) or congenital late bilateral group (received first implant aged ≤3½ years and second aged >3½ years, n=38). Children with some bilateral acoustic hearing until the age of 3½ years, who subsequently became profoundly deaf and received bilateral cochlear implants, were in the acquired/progressive group (n=16). There were 32 children in the normally hearing group. Children completed tests of sound-source localization and spatial release from masking (a measure of the ability to use both ears to understand speech in noise).

RESULTS

The acquired/progressive group localized more accurately than both groups of congenitally deaf children (p<0.05). All three groups of children with cochlear implants showed similar spatial release from masking. The normally hearing group localized more accurately than all groups with bilateral cochlear implants and displayed more spatial release from masking than the congenitally deaf groups on average (p<0.05).

CONCLUSION

Children with bilateral cochlear implants and early experience of acoustic hearing showed more accurate localization skills, on average, than children born profoundly deaf.

Quality standards for bone conduction implants

CONCLUSION

Bone conduction implants are useful in patients with conductive and mixed hearing loss for whom conventional surgery or hearing aids are no longer an option. They may also be used in patients affected by single-sided deafness.

OBJECTIVES

To establish a consensus on the quality standards required for centers willing to create a bone conduction implant program.

METHOD

To ensure a consistently high level of service and to provide patients with the best possible solution the members of the HEARRING network have established a set of quality standards for bone conduction implants. These standards constitute a realistic minimum attainable by all implant clinics and should be employed alongside current best practice guidelines.

RESULTS

Fifteen items are thoroughly analyzed. They include team structure, accommodation and clinical facilities, selection criteria, evaluation process, complete preoperative and surgical information, postoperative fitting and assessment, follow-up, device failure, clinical management, transfer of care and patient complaints.

Changes in children's speech discrimination and spatial release from masking between 2 and 4 years after sequential cochlear implantation

OBJECTIVE

To document changes in speech reception thresholds (SRTs) and spatial release from masking (SRM) for sequentially implanted children at 2 and 4 years after they received their second cochlear implant (CI2).

METHODS

Participants were 17 children who consistently used two sequentially implanted and optimally programmed CIs. SRTs were measured monaurally in quiet and binaurally in noise using the adaptive McCormick toy discrimination test. Speech signals were presented from 0° azimuth and noise from 0°, +90° or  -90° azimuth. SRM was calculated from SRTs in noise. Measurements were made at 2 and 4 year post-CI2.

RESULTS

There were significant improvements over time in SRTs in quiet, SRTs in noise and SRM. SRTs in quiet improved more for CI2 than for the first implant (CI1). SRTs in noise and SRM improved more when noise was presented closest to CI1 than when closest to CI2. Performance became more symmetrical over time.

DISCUSSION

Despite prolonged periods of unilateral auditory deprivation sequentially implanted children exhibited continued improvement in SRT and SRM. These results are valuable in setting expectations for and counselling families of children considering sequential CIs.

Towards a consensus on a hearing preservation classification system

CONCLUSION

The comprehensive Hearing Preservation classification system presented in this paper is suitable for use for all cochlear implant users with measurable pre-operative residual hearing. If adopted as a universal reporting standard, as it was designed to be, it should prove highly beneficial by enabling future studies to quickly and easily compare the results of previous studies and meta-analyze their data.

OBJECTIVES

To develop a comprehensive Hearing Preservation classification system suitable for use for all cochlear implant users with measurable pre-operative residual hearing.

METHODS

The HEARRING group discussed and reviewed a number of different propositions of a HP classification systems and reviewed critical appraisals to develop a qualitative system in accordance with the prerequisites.

RESULTS

The Hearing Preservation Classification System proposed herein fulfills the following necessary criteria: 1) classification is independent from users' initial hearing, 2) it is appropriate for all cochlear implant users with measurable pre-operative residual hearing, 3) it covers the whole range of pure tone average from 0 to 120 dB; 4) it is easy to use and easy to understand.

Feasibility of cochlear implantation in Mucopolysaccharidosis

Mucopolysaccharidoses (MPS) are a group of rare inherited metabolic disorders resulting from deficiencies of particular enzymes involved in the breakdown of glycosaminoglycans. Amongst the manifestations of MPS within the head and neck patients may develop conductive, mixed or sensorineural hearing loss.

OBJECTIVE

The main objective of this paper is to describe the management of profound sensorineural hearing loss in children with Mucopolysaccaridosis. The primary outcome measures for this case series were improvement in auditory performance and speech perception scores following cochlear implantation. Secondary outcome measures included surgical complications.

METHODS

We carried out a casenote review of the first two cases of cochlear implantation (CI) to rehabilitate profound sensory neural hearing loss in Mucopolysaccharidoses. Improvement in auditory performance was measured by categories of auditory performance (CAP) score, speech reception score (SRS) and the IHR McCormick toy discrimination test.

RESULTS

Both patients with MPS had demonstrable benefit from CI in terms of auditory performance and speech perception. The first patient improved from pre-operatively only managing to recognise environmental sounds to understanding conversation without lip-reading with a familiar talker. Following CI, the second patient can discriminate speech in noisy environments to a degree, without lip-reading. No peri-operative complications were noted in either patient.

CONCLUSION

As the medical management of the MPS has progressed there is likely to be a corresponding increase in survival. This increased life-expectancy will likely lead to greater numbers of patients with MPS surviving long enough to develop profound hearing loss. Likewise, when considering the risks and benefits of quality of life interventions such as CI in patients with MPS, it is more likely that the risks of surgery and general anaesthesia will be considered acceptable. Clinicians managing such patients will need to be aware of these developments.

Skin flap thickness in cochlear implant patients - a prospective study

The thickness and quality of the skin overlying a cochlear implant is important for its integrity. It should be thick enough to protect the implant and prevent flap breakdown yet should not be so thick that it impedes the electronic signal or causes difficulty wearing the coil because of loss of the magnetic coupling. The principle of this study was to devise a method to assess the thickness of skin over a cochlear implant receiver stimulator package and prospectively measure this thickness during the first year following surgery. All patients studied were implanted with MED-EL COMBI 40+ implants. The first cohort consisted of 35 adults; the second 23 children. Various methods of measurement were assessed. In this study the principle of the Hall Effect electrode was used to measure the magnetic flux density of the magnet within the receiver stimulator package. Following standardization, results showed that skin thickness significantly thinned in the adult group before stabilizing. This was less obvious in children, probably due to the effect of the skin thickening as the child grows. Knowledge of skin thickness has implications relating to the functioning of an implant and avoiding potential flap related complications.

The Bradford bone-anchored hearing aid programme: impact of the multidisciplinary team

Objectives: The aim of this study was to assess the impact on implant survival, abutment skin reaction and patient satisfaction in patients implanted with a bone-anchored hearing aid (BAHA), following the introduction of a multidisciplinary team (MDT) in 1997.

Design and methods: Part prospective and retrospective analysis. Implant survival and cause of failures were recorded along with abutment skin reaction (graded as none, mild, moderate and severe, according to the amount of wound care required). Patient satisfaction and quality of life were assessed using a questionnaire enquiring about several aspects of the use and benefits of their BAHA.

Setting and participants: Eighty patients treated at the Bradford Royal Infirmary between 1991 and 2005. The unit is a recognized tertiary referral centre.

Results and conclusions: Twelve out of 80 implants failed, giving an overall failure rate of 15 per cent. Kaplan–Meier survival curves show a steady decrease in implant survival. The MDT had a positive effect on implant survival and adverse skin reactions, with a higher proportion of patients experiencing no reaction after its introduction. There was a 92.5 per cent response rate to the questionnaire. Overall patient satisfaction was high, both before and after the introduction of the MDT.

Cochlear implantation in Jervell and Lange-Nielsen syndrome

A case of familial prolonged QT interval and congenital sensorineural hearing loss is described emphasising the diagnostic and management implications. Jervell and Lange-Nielsen syndrome is important because of its potential association with sudden death in children with congenital sensorineural deafness. It is known to be associated with mutations of the genes KCNQ1 (KVQTI) and KCNE1 (Isk). The underlying molecular abnormality leads to cardiac and cochlear dysfunction through a potassium channel defect. All children with congenital sensorineural hearing loss who have suffered unexplained syncopal attacks or convulsions should be screened for this syndrome. There is also a strong case for including a 12 lead ECG as part of the investigative work up of all children with congenital sensorineural deafness in whom a firm aetiology has not been established.

Cochlear and middle ear implants: advances for the hearing impaired

We have entered into an era of surgical audiology with cochlear and middle ear implants. With both devices there are distinct phases of patient management--patient selection, surgery, programming and rehabilitation. These phases and issues relating to the implants themselves are considered in this article.

Improvement in severe insulin resistance with frequent injections of lispro insulin

Extreme insulin resistance is common in obese African Americans with type 2 diabetes. This case report describes an obese African-American woman who was treated with subcutaneous injections of lispro insulin every 2 hours with resultant decrease of mean daily blood glucose from 264.7 mg/dL to 111 mg/dL and in insulin requirement from 479 U/24 hours to 60 U/24 hours. This case demonstrates that extreme insulin resistance is reversible in the short term.

An endoscopic photographic comparison of nasal drug delivery by aqueous spray

There is general agreement that the delivery of topical nasal medication by sprays is suboptimal. This study examines the distribution of spray to the anterior end of the middle turbinate as a guide to the distribution to the middle meatus by means of an endoscopic photographic comparison using dyed aqueous nasal spray. The technique was found to be reproducible. The effect of vigorously inhaling whilst spraying was studied by means of a randomized crossover trial and was found to have no significant effect. This technique could be used in conjunction with other means of assessing intranasal distribution when assessing improved topical nasal drug delivery systems.

Intracochlear factors contributing to psychophysical percepts following cochlear implantation

The performance of cochlear implant patients may be related to intracochlear, histopathological factors. We have performed detailed post-mortem examinations of five human, implanted cochleas and for each electrode correlated the psychophysical threshold, comfortable level and dynamic range with spiral ganglion cell survival, presence of fibrous tissue and/or new bone, and distance between the centers of the electrode bands and Rosenthal's canal. The psychophysical parameters were strongly interrelated. Threshold and comfort levels correlated with the distance between the electrodes and Rosenthal's canal. Threshold levels also correlated with the presence of intracochlear fibrous tissue and new bone, especially with the former. The dynamic range showed a negative correlation with intracochlear pathology, especially with new bone. Comfort levels and dynamic range were related to spiral ganglion cell survival. The distance between the electrodes and the modiolus increased with increasing levels of fibrous tissue and new bone. Spiral ganglion cell survival was decreased with increasing levels of fibrous tissue and new bone.

Acute suppurative parotitis and facial paralysis

A case of facial nerve paralysis secondary to acute suppurative parotitis is described. This is a rare complication in the absence of malignant processes in the parotid.

Anomaly of the facial nerve and cochlear implantation

The incidence of preoperative damage to the facial nerve in cochlear implantation is very low. The course of the facial nerve is not routinely evaluated preoperatively, but variations in its course can restrict access to the round window and impede implantation. In 5 of 42 operations, direct visualization of the round window was not possible. In 1 patient there was an obvious congenital bifurcation. Successful implantation was made possible by mobilizing the nerve.

An open safety pin in the larynx: a case report

Inhalation of a foreign body is a serious event. The number of foreign bodies that become impacted in the larynx is small and requires urgent recognition. We describe the case of a six-month-old baby with an impacted open safety pin in the larynx. The sharp end of the safety pin was upwards and had penetrated the anterior end of the left vocal fold. We discuss the management and describe our method of removal of the foreign body. Tracheostomy was not required in this case and the child had an uneventful recovery. A brief review of the literature is included.

A prospective study of factors which may predispose to post-operative tonsillar fossa haemorrhage

Adeno-tonsillectomy and tonsillectomy are frequently performed and haemorrhage remains an important post-operative complication. A prospective study of 1090 patients undergoing surgery over a 12-month period was undertaken investigating whether the following factors influenced post-operative haemorrhage: age and sex of patients, method of tonsillectomy, haemostasis and premedication, month of operation and experience of surgeon. A significantly higher incidence of post-operative haemorrhage occurred in the group aged 16-25 years and significantly more males suffered post-operative haemorrhage. This haemorrhage more frequently occurred in the warmer months of May to July. Guillotine tonsillectomy was found to be as effective as dissection and no higher incidence of post-operative haemorrhage was recorded. Method of haemostasis, surgical experience and premedication did not influence the outcome. We conclude that the guillotine used in controlled circumstances is as safe as dissection.

The presentation of laryngeal tuberculosis

Laryngeal tuberculosis is now a rare disease. We report 6 patients presenting within a 10-year period (1976-1986). Symptoms and signs often mimic carcinoma or chronic non-specific laryngitis. Greater clinical awareness and a chest radiograph prior to direct laryngoscopy may alert the clinician to the possibility of tuberculosis. The diagnosis is established by laryngeal biopsy.

Chemoprophylaxis in major head and neck surgery

Wound infections are a significant complication following major oncological head and neck surgery. In view of the controversy surrounding the use of chemoprophylaxis a controlled trial was designed. Intravenous Augmentin (amoxycillin and clavulanic acid) was shown to reduce significantly (P less than 0.025) the incidence of postoperative sepsis.

Bacteriological assessment of patients undergoing major head and neck surgery

The use of chemoprophylaxis in major Head and Neck surgery is controversial. Prior to conducting a prospective trial a controlled microbiological monitoring of 32 patients was performed to determine a suitable antibiotic for prophylaxis. Wound infection occurred in 22 (68%) patients with fistulae occurring in 10 of these patients (45.5%). Pre-operative cultures were of limited value in predicting subsequent sepsis. Gram-negative aerobic bacilli were the commonest group of pathogens (34.4%) isolated post-operatively. From projected resistance profiles of pathogenic and opportunistic bacteria amoxycillin and clavulanic acid (Augmentin, Beecham Pharmaceuticals) was chosen as a suitable antibiotic.

A comparison of the effects of intermittent and continuous nasogastric feeding on the oxygen consumption and nitrogen balance of patients after major head and neck surgery

Ten patients were fed by nasogastric tube for 5 days after major surgery of the head and neck. Five were fed by continuous infusion 24 h/day using an enteral nutrition pump and five were fed comparable quantities by 2-h bolus administration between 0600 and 2200 h. Those fed by bolus had lower resting oxygen consumption on the 4th and 5th postoperative days and better cumulative nitrogen balance over the 5 days than the continuously fed group. It appears that metabolically it may be better to use an intermittent feeding regimen than a continuous one when feeding patients postoperatively via a nasogastric tube.

Ectopic gastric mucosa in the upper esophagus as a cause of dysphagia

A rare case of dysphagia, caused by ectopic gastric mucosa situated in the upper esophagus, is reported.