Mild matters: trial learnings and importance of community engagement in research for early identified bilateral mild hearing loss.

Introduction: Early identification of mild hearing loss has resulted in early hearing amplification without adequate evidence of effectiveness. This paper describes learnings from a pilot trial, combined with a qualitative study, to highlight the importance of community engagement in designing research studies to determine whether early amplification benefits young children with bilateral mild hearing loss. Methods: PART 1 of the study is a proof-of-concept non-blinded multi-centre randomised controlled trial (RCT) of hearing device fitting vs. no fitting aimed to gather preliminary data and determine its acceptability/feasibility in children <2 years old with bilateral mild hearing loss. Results: PART 2 is a qualitative study to understand the barriers/enablers to RCT participation. Of 40 potentially eligible families, nine (23%) declined, three were uncontactable (7%), 26 (65%) ineligible: of these, nine (35%) did not meet hearing threshold inclusion criteria, 11 (42%) were already fitted or had made decisions on fitting hearing device, two (7%) had conductive loss and four (16%) were ineligible for other reasons. Two of 11 (18%) eligible families were randomised. With the limited sample size, outcome measures were not compared between groups. Both participants completed the trial, reported the RCT to be acceptable, and neither changed group post-enrolment. Discussion: Whilst recruitment uptake could potentially be increased by altering the eligibility criteria, better communication with and reimbursement of clinicians as recruiters, and improving awareness of the study amongst external stakeholders, the RCT methodology does not conform to family-centred practice, and potentially raises ethical concerns regarding potential adverse consequences of not offering early amplification. Parental perception of losing control over choice of management due to randomisation is not an easily modifiable factor. Alternative methodological approaches without randomisation are required to determine whether hearing amplification benefits infants with mild hearing loss.Clinical Trial Registration: identifier [ACTRN12618001608257].

Factors associated with blunt internal carotid artery injury in petrous temporal bone fractures.

INTRODUCTION: Traumatic internal carotid artery (ICA) injuries are an uncommon complication of petrous temporal bone (PTB) fractures that can have devastating consequences of stroke, haemorrhage and death. Current guidelines suggest that all PTB fractures should be screened for blunt cerebrovascular injury, however clinical practice varies. The purpose of this study was to identify features associated with PTB fractures that increase the likelihood of ICA injury. METHODS: A retrospective cohort study was performed on all patients with PTB fractures who were investigated with computed-tomography angiography (CTA) scan admitted to a Level One Trauma Service in Melbourne, Australia from 2015-2020. Patient demographic and injury data were obtained from The Royal Melbourne Hospital Trauma Registry and medical records. Multivariate binomial logistic regression was performed to identify features associated with ICA injury. RESULTS: Out of 377 patients with 419 PTB fractures, 205 received a CTA scan and were included, identifying 22 ICA injuries (9.4%). The median age of ICA injuries was 33 (IQR 23-61), median Abbreviated Injury Scale (AIS) score for the head region was 5 (IQR 5-5) and the in-hospital mortality rate was 45.5%, mainly due to unsurvivable brain injury. Five patients (22.7%) developed ICA-specific complications of stroke or carotid-cavernous fistula. We identified five factors that were significantly associated with ICA injury. These included PTB fractures involving the carotid canal (OR 6.7, 95% CI 1.9-23.9, p=0.003), presenting with an initial GCS less than nine (OR 5.7, 95% CI 1.2-26.5, p=0.025) and increasing head AIS (OR 2.4, 95% CI 1.2-4.6, p=0.009). Mechanisms of injury that were associated with ICA injury were motor vehicle crash (OR 4.4, 95% CI 1.4-14.2, p=0.012) and motorbike crash (OR 4.6, 95% CI 1.2-18, p=0.029). CONCLUSION: Patients with PTB fractures and an additional feature of carotid canal involvement, presenting GCS less than nine, increasing head AIS indicative of severe head trauma or mechanism of injury by motor vehicle or motorbike crash, are at an increased risk of ICA injury and should be screened with a CTA scan.

Electrocochleography triggered intervention successfully preserves residual hearing during cochlear implantation: Results of a randomised clinical trial.

BACKGROUND: Preservation of natural hearing during cochlear implantation is associated with improved speech outcomes, however more than half of implant recipients lose this hearing. Real-time electrophysiological monitoring of cochlear output during implantation, made possible by recording electrocochleography using the electrodes on the cochlear implant, has shown promise in predicting hearing preservation. Sudden drops in the amplitude of the cochlear microphonic (CM) have been shown to predict more severe hearing losses. Here, we report on a randomized clinical trial investigating whether immediate surgical intervention triggered by these drops can save residual hearing. METHODS: A single-blinded placebo-controlled trial of surgical intervention triggered when CM amplitude dropped by at least 30% of a prior maximum amplitude during cochlear implantation. Intraoperative electrocochleography was recorded in 60 adults implanted with Cochlear Ltd's Thin Straight Electrode, half randomly assigned to a control group and half to an interventional group. The surgical intervention was to withdraw the electrode in ½-mm steps to recover CM amplitude. The primary outcome was hearing preservation 3 months following implantation, with secondary outcomes of speech-in-noise reception thresholds by group or CM outcome, and depth of implantation. RESULTS: Sixty patients were recruited; neither pre-operative audiometry nor speech reception thresholds were significantly different between groups. Post-operatively, hearing preservation was significantly better in the interventional group. This was the case in absolute difference (median of 30 dB for control, 20 dB for interventional, χ² = 6.2, p = .013), as well as for relative difference (medians of 66% for the control, 31% for the interventional, χ² = 5.9, p = .015). Speech-in-noise reception thresholds were significantly better in patients with no CM drop at any point during insertion compared with patients with a CM drop; however, those with successfully recovered CMs after an initial drop were not significantly different (median gain required for speech reception score of 50% above noise of 6.9 dB for no drop, 8.6 for recovered CM, and 9.8 for CM drop, χ² = 6.8, p = .032). Angular insertion depth was not significantly different between control and interventional groups. CONCLUSIONS: This is the first demonstration that surgical intervention in response to intraoperative hearing monitoring can save residual hearing during cochlear implantation.

Intraoperative Observational Real-time Electrocochleography as a Predictor of Hearing Loss After Cochlear Implantation: 3 and 12 Month Outcomes.

OBJECTIVE: A decrease in intracochlear electrocochleographic (ECochG) amplitude during cochlear implantation has been associated with poorer postoperative hearing preservation in several short-term studies. Here, we relate the stability of ECochG during surgery to hearing preservation at 3- and 12-months. METHODS: Patients with hearing ≤80-dB HL at 500 Hz were implanted with a slim-straight electrode array. ECochG responses to short, high-intensity, 500-Hz pure tones of alternating polarity were recorded continuously from the apical-most electrode during implantation. No feedback was provided to the surgeon. ECochG amplitude was derived from the difference response, and implantations classified by the presence ("ECochG drop") or absence ("no drop") of a ≥30% reduction in ECochG amplitude during insertion. Residual hearing (relative and absolute) was reported against the ECochG class. RESULTS: ECochG was recorded from 109 patients. Of these, interpretable ECochG signals were recorded from 95. Sixty-six of 95 patients had an ECochG drop during implantation. Patients with an ECochG drop had poorer preoperative hearing above 1000 Hz. Hearing preservation (in decibels, relative to preoperative levels and functionally) was significantly poorer at 250-, 500-, and 1000-Hz at 3 months in patients exhibiting an ECochG drop. Twelve-month outcomes were available from 85 patients, with significantly poorer functional hearing, and greater relative and absolute hearing loss from 250 to 1000 Hz, when an ECochG drop had been encountered. CONCLUSION: Patients exhibiting ECochG drops during implantation had significantly poorer hearing preservation 12 months later. These observational outcomes support the future development of surgical interventions responsive to real-time intracochlear ECochG. Early intervention to an ECochG drop could potentially lead to prolonged improvements in hearing preservation.

Cochlear Patency After Translabyrinthine Vestibular Schwannoma Surgery.

OBJECTIVES: To determine the temporal occurrence of fluid signal changes on T2-weighted magnetic resonance imaging (T2MRI) that occur in the cochlear lumen after translabyrinthine surgery. STUDY DESIGN: Retrospective case control study. SETTING: Tertiary referral neurotology center. SUBJECTS AND METHODS: Seventy-one patients were identified who underwent translabyrinthine removal of a vestibular schwannoma between 2010 and 2014; of these 49 were included as they had postoperative T2 MRI at 6, 18, and 48 months available postsurgery. Magnetic resonance imaging scans were scored base on fluid signal changes within the cochlea. RESULTS: In total, 147 magnetic resonance imaging scans were reviewed on 49 patients. In the cohort analysis 86% of patients showed evidence of fluid signal changes 48 months postoperatively. Ninety-five percent of patients who went on to demonstrate loss of fluid signal at 48 months had already shown changes at 6 months postsurgery. The majority of cochlea signal changes identified at 6 months were minor (72% Grade 1) while at 48 months this had progressed to severe (71% Grade 2 or 3). Of the patients with a normal cochlea at 6 months 78% maintained a normal cochlea to the 48-month scan. CONCLUSION: Cochlear signal changes suggestive of fibrosis occurred in most patients following translabyrinthine removal of vestibular schwannoma. Given the early onset of cochlear fluid signal changes on T2MRI, and the progression of these changes on subsequence imaging, cochlear implantation would ideally need to be performed either simultaneous to translabyrinthine surgery or as an early second-stage procedure to maximize the chance of a successful electrode insertion, or one can consider a placeholder as well.

Electrophysiological Evidence of the Basilar-Membrane Travelling Wave and Frequency Place Coding of Sound in Cochlear Implant Recipients.

AIM: To obtain direct evidence for the cochlear travelling wave in humans by performing electrocochleography from within the cochlea in subjects implanted with an auditory prosthesis. BACKGROUND: Sound induces a travelling wave that propagates along the basilar membrane, exhibiting cochleotopic tuning with a frequency-dependent phase delay. To date, evoked potentials and psychophysical experiments have supported the presence of the travelling wave in humans, but direct measurements have not been made. METHODS: Electrical potentials in response to rarefaction and condensation acoustic tone bursts were recorded from multiple sites along the human cochlea, directly from a cochlear implant electrode during, and immediately after, its insertion. These recordings were made from individuals with residual hearing. RESULTS: Electrocochleography was recorded from 11 intracochlear electrodes in 7 ears from 6 subjects, with detectable responses on all electrodes in 5 ears. Cochleotopic tuning and frequency-dependent phase delay of the cochlear microphonic were demonstrated. The response latencies were slightly shorter than those anticipated which we attribute to the subjects' hearing loss. CONCLUSIONS: Direct evidence for the travelling wave was observed. Electrocochleography from cochlear implant electrodes provides site-specific information on hair cell and neural function of the cochlea with potential diagnostic value.

Hearing Preservation Outcomes for 139 Cochlear Implant Recipients Using a Thin Straight Electrode Array.

OBJECTIVE: To assess the hearing preservation outcomes in a large group of adult cochlear implant recipients implanted with a thin straight electrode array using atraumatic surgical techniques. Factors affecting hearing preservation will be investigated. STUDY DESIGN: Prospective cohort study undertaken at the Royal Victorian Eye and Ear Hospital in Melbourne, Australia from December 2010 to May 2015. SETTING: Tertiary academic hospital. PATIENTS: One hundred thirty-nine adults undergoing cochlear implantation (CI). MAIN OUTCOME MEASURE: Primary outcome measure of interest was pre and postoperative pure-tone audiometry. RESULTS: Median low-frequency hearing change for the whole group of 139 recipients was -22.5 dB at the 3 months postop point. Eighty-six participants had functional preoperative low-frequency hearing (≤70 dB average at 250 and 500 Hz). Of these, 90.7% retained measureable hearing at 3 months postimplant. 39.5% of this original 86 participants retained functional hearing at 3 months postimplant. At 12 months postimplant, those who retained functional hearing at 3 months had no significant change in hearing. The group who lost functional hearing continued to have a significant deterioration in low-frequency hearing. Degree of hearing loss preimplant was identified as a predictor for the preservation of hearing postoperatively. CONCLUSION: Preservation of hearing is possible following atraumatic cochlear implant surgery with a thin straight electrode array. The amount of hearing preserved seems to be variable, and factors related to this variability are not yet known. The results of the present study suggest preoperative low-frequency hearing at or better than 45 dB may be related to preservation of functional hearing.

The effect of interdevice interval on speech perception performance among bilateral, pediatric cochlear implant recipients.

OBJECTIVES/HYPOTHESIS: To determine if prolongation of the interdevice interval in children receiving bilateral cochlear implants adversely affects speech perception outcomes. STUDY DESIGN: Retrospective chart review. METHODS: Retrospective review of our pediatric cochlear implant database was performed. Children who had undergone revision surgery or had less than 12 months listening experience with either the first or second implant were excluded. The interdevice interval, best Phonetically Balanced Kindergarten word lists (PBK) score from each ear, and demographic data about each patient were collected. A ratio of PBK was generated (PBK second side/PBK first side) to minimize potential confounding from other individual patient factors that affect speech outcomes. RESULTS: Two hundred forty children met the study criteria. Mean age at first cochlear implantation (CI) was 3.2 years (0.6-17.9), and the second was 6.6 years (0.8-22.4). Mean best PBK score from the first CI side was 83.8% (0-100), and the second was 67.5% (0-100) (P < .001). When the PBK ratio was plotted against interdevice interval, R(2) was 0.47 (P < .001). When analyzed for hearing stability, those with a progressive loss history demonstrated less influence of prolonged interdevice interval on performance. Multivariate analysis did not identify other factors influencing the ratio. A line of best fit for those with stable hearing loss suggested best outcomes were with an interdevice interval less than 3 to 4 years. Beyond 7 to 8 years, very few achieved useful speech recognition from the second CI. CONCLUSIONS: Where possible, the second implant should be received within 3 to 4 years of the first to maximize outcome in those with stable, severe to profound sensorineural hearing loss. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:2389-2394, 2016.

Intraoperative Real-time Cochlear Response Telemetry Predicts Hearing Preservation in Cochlear Implantation.

AIM: To monitor cochlear function during cochlear implantation and determine correlations with postoperative acoustic hearing. BACKGROUND: Cochlear response telemetry measures cochlear function directly from cochlear implant electrodes. We have adapted this system to provide real-time cochlear response telemetry (RT-CRT) monitoring of a patient's acoustic hearing as the cochlear implant electrode array is inserted. METHODS: Eighteen subjects (1 child and 17 adults) with sloping high frequency hearing loss were implanted with Cochlear Ltd slim straight arrays (CI422/CI522). Tone bursts (500 Hz, 100-110 dB) were presented at 14 Hz continuously during the array insertion. RT-CRT amplitudes were correlated with surgical manoeuvres recorded on the video from the operating microscope and with postoperative pure tone audiograms. RESULTS: Despite an excellent overall rate of complete or partial hearing preservation (79%), RT-CRT identified that in 47% of these implantations there was transient or permanent reduction in the amplitude of the cochlear microphonic (CM). Patients with a preserved CM at the end of insertion had on average 15 dB better low-frequency hearing preservation. The CM amplitude was most vulnerable during the last few millimeters of insertion or when inadvertent movement of the array occurred after full insertion. Physical contact/elevation of the basilar membrane is hypothesized as a likely mechanism of hearing loss rather than overt physical trauma. CONCLUSION: RT-CRT can be used to predict early postoperative hearing loss and to potentially refine surgical technique. In the future, feedback of RT-CRT may prove to be a valuable tool for maximizing preservation of residual hearing or providing feedback on electrode contact with the basilar membrane.

Management of Children with Severe, Severe-profound, and Profound Sensorineural Hearing Loss.

Management of children with severe, severe-profound, and profound sensorineural hearing loss is best achieved using a family-centered approach by a team of health professionals, including audiologists, speech pathologists, otolaryngologists, pediatricians, genetic counselors, and early intervention programs. Early diagnosis and intervention offers the best chance for speech and language acquisition. Although hearing aids can provide some of the needed information, they are often not sufficient for spoken language development and a cochlear implant is needed. This must be combined with a strong audiology and speech therapy rehabilitation program.

Pre-operative simulation of pediatric mastoid surgery with 3D-printed temporal bone models.

OBJECTIVES: As the process of additive manufacturing, or three-dimensional (3D) printing, has become more practical and affordable, a number of applications for the technology in the field of pediatric otolaryngology have been considered. One area of promise is temporal bone surgical simulation. Having previously developed a model for temporal bone surgical training using 3D printing, we sought to produce a patient-specific model for pre-operative simulation in pediatric otologic surgery. Our hypothesis was that the creation and pre-operative dissection of such a model was possible, and would demonstrate potential benefits in cases of abnormal temporal bone anatomy. METHODS: In the case presented, an 11-year-old boy underwent a planned canal-wall-down (CWD) tympano-mastoidectomy for recurrent cholesteatoma preceded by a pre-operative surgical simulation using 3D-printed models of the temporal bone. The models were based on the child's pre-operative clinical CT scan and printed using multiple materials to simulate both bone and soft tissue structures. To help confirm the models as accurate representations of the child's anatomy, distances between various anatomic landmarks were measured and compared to the temporal bone CT scan and the 3D model. RESULTS: The simulation allowed the surgical team to appreciate the child's unusual temporal bone anatomy as well as any challenges that might arise in the safety of the temporal bone laboratory, prior to actual surgery in the operating room (OR). There was minimal variability, in terms of absolute distance (mm) and relative distance (%), in measurements between anatomic landmarks obtained from the patient intra-operatively, the pre-operative CT scan and the 3D-printed models. CONCLUSIONS: Accurate 3D temporal bone models can be rapidly produced based on clinical CT scans for pre-operative simulation of specific challenging otologic cases in children, potentially reducing medical errors and improving patient safety.

Intraoperative round window electrocochleography and speech perception outcomes in pediatric cochlear implant recipients.

OBJECTIVES: The goal was to measure the magnitude of cochlear responses to sound in pediatric cochlear implant recipients at the time of implantation and to correlate this magnitude with subsequent speech perception outcomes. DESIGN: A longitudinal cohort study of pediatric cochlear implant recipients was undertaken. Intraoperative electrocochleographic (ECoG) recordings were obtained from the round window in response to a frequency series at 90 dB nHL in 77 children totaling 89 ears (12 were second side surgeries) just before device insertion. The increase in intraoperative time was approximately 10 min. An ECoG "total response" metric was derived from the summed magnitudes of significant responses to the first, second, and third harmonics across a series of frequencies. A subset of these children reached at least 9 months of implant use and were old enough for the phonetically balanced kindergarten (PB-k) word test to be administered (n = 26 subjects and 28 ears). PB-k scores were compared to the ECoG total response and other biologic and audiologic variables using univariate and multiple linear regression analyses. RESULTS: ECoG responses were measurable in almost all ears (87 of 89). The range of ECoG total response covered about 60 dB (from ~0.05 to 50 µV). Analyzing individual ECoG recordings in bilaterally implanted children revealed poor concordance between the measured response in the first versus second ear implanted (r = 0.21; p = 0.13; n = 12). In a univariate linear regression, the ECoG total response was significantly correlated with PB-k scores in the subset of 26 subjects who were able to be tested and accounted for 32% of the variance (p = 0.002, n = 28). Preoperative pure-tone average (PTA) accounted for slightly more of the variance (r = 0.37, p = 0.001). However, ECoG total response and PTA were significantly but only weakly correlated (r = 0.14, p = 0.001). Other significant predictors of speech performance included hearing stability (stable versus progressive) and age at testing (22 and 16% of the variance, respectively). In multivariate analyses with these four factors, the ECoG accounted for the most weight (ß = 0.36), followed by PTA (ß = 0.26). In a hierarchical multiple regression analysis, the most parsimonious models that best predicted speech perception outcomes included three variables: ECoG total response, and any two of preoperative PTA, age at testing, or hearing stability. The various three factor models each predicted approximately 50% of the variance in word scores. Without the ECoG total response, the other three factors predicted 36% of variance. CONCLUSIONS: Intraoperative round window ECoG recordings are reliably and easily obtained in pediatric cochlear implant recipients. The ECoG total response is significantly correlated with speech perception outcomes in pediatric implant recipients and can account for a comparable or greater proportion of variance in speech perception than other bio-audiologic factors. Intraoperative recordings can potentially provide useful prognostic information about acquisition of open set speech perception in implanted children.

Effect of cochlear nerve electrocautery on the adult cochlear nucleus.

HYPOTHESIS: Electrocauterization and subsequent transection of the cochlear nerve induce greater injury to the cochlear nucleus than sharp transection alone. BACKGROUND: Some studies show that neurofibromatosis Type 2 (NF2) patients fit with auditory brainstem implants (ABIs) fail to achieve speech perception abilities similar to ABI recipients without NF2. Reasons for these differences remain speculative. One hypothesis posits poorer performance to surgically induced trauma to the cochlear nucleus from electrocautery. Sustained electrosurgical depolarization of the cochlear nerve may cause excitotoxic-induced postsynaptic nuclear injury. Equally plausible is that cautery in the vicinity of the cochlear nucleus induces necrosis. METHODS: The cochlear nerve was transected in anesthetized adult gerbils sharply with or without bipolar electrocautery at varying intensities. Gerbils were perfused at 1, 3, 5, and 7 days postoperatively; their brainstem and cochleas were embedded in paraffin and sectioned at 10 µm. Alternate sections were stained with flourescent markers for neuronal injury or Nissl substance. In additional experiments, anterograde tracers were applied directly to a sectioned eighth nerve to verify that fluorescent-labeled profiles seen were terminating auditory nerve fibers. RESULTS: Cochlear nerve injury was observed from 72 hours postoperatively and was identical across cases regardless of surgical technique. Postsynaptic cochlear nucleus injury was not seen after distal transection of the nerve. By contrast, proximal transection was associated with trauma to the cochlear nucleus. CONCLUSION: Distal application of bipolar electrocautery seems safe for the cochlear nucleus. Application near the root entry zone must be used cautiously because this may compromise nuclear viability needed to support ABI stimulation.

Scala tympani cochleostomy survey: a follow-up study.

OBJECTIVES/HYPOTHESIS: To reassess cochleostomy techniques among North American cochlear implant surgeons after a 6-year period of widespread education and research on the topic. STUDY DESIGN: Prospective cohort study. METHODS: A multiple-choice survey of cochlear implant techniques was distributed to surgeons attending the William House Cochlear Implant Study Group in 2006 and 2012. This survey contained questions regarding routine surgical access and cochleostomy techniques. Responses were anonymous, and >50% were repeat respondents. Statistical analysis sought changes in technique in the past 6 years. RESULTS: Comparisons between 2006 and 2012 responses revealed no significant changes in the proportion of surgeons identifying the facial nerve or chorda tympani. By contrast, respondents in 2012 were more likely to drill off the round window niche overhang (P < .001), use a round window insertion (P < .001), or make a smaller cochleostomy (P = .003). In two images of a transfacial recess approach, there was a significant increase in the proportion choosing an inferior or anterior cochleostomy site over a superior location (image 1, 76% in 2006 to 92% in 2012, P = .003; image 3, 78% to 90%, respectively, P = .044). CONCLUSIONS: This repeat survey documents a change in practice among cochlear implant surgeons. Specifically, scala tympani access techniques now appear to be more consistent with known anatomical relationships in the round window region. These findings may have resulted from the concerted education and research efforts over the past 6 years.

Round window electrocochleography and speech perception outcomes in adult cochlear implant subjects: comparison with audiometric and biographical information.

HYPOTHESIS: Intraoperative round window (RW) electrocochleography (ECoG) can help predict speech perception outcomes in adult cochlear implant (CI) recipients. BACKGROUND: Speech perception outcomes using CIs are highly variable. Recent data demonstrated that intraoperative ECoG could account for nearly half the variance in postoperative word scores. The present study seeks to update this correlation with a larger sample size and determine if addition of clinical variables improves the prediction. METHODS: Intraoperative RW ECoG was performed in adult subjects undergoing CI. Amplitudes of the ongoing response to tone bursts of multiple frequencies at 85 to 95 dB HL were summed to obtain the total response (ECoG-TR). ECoG-TR was correlated with postoperative speech perception scores. Multiple linear regression was used to combine clinical factors with the ECoG-TR. RESULTS: The ECoG-TR accounted for 40% of the variance in CNC word scores (n = 32). The preoperative pure tone average (PTA) was the only clinical factor with a significant correlation (r² = 20%). The ability to predict word scores using ECoG-TR and PTA, or after addition of age and duration of hearing loss, was not significantly different from using ECoG-TR alone. For 2 outliers, ECoG-TR predicted a better word score than obtained. CONCLUSIONS: The measurement of cochlear physiology before CI, reduced to a single variable, is a better predictor of postoperative speech perception than common clinical factors. Additional analysis of the outliers showed that waveform morphology can provide distinct information in individual cases.

Intracochlear electrocochleography during cochlear implantation.

OBJECTIVE: Electrophysiologic responses to acoustic stimuli are present in nearly all cochlear implant recipients when measured at the round window (RW). Intracochlear recording sites might provide an even larger signal and improve the sensitivity and the potential clinical utility of electrocochleography (ECoG). Thus, the goal of this study is to compare RW to intracochlear recording sites and to determine if such recordings can be used to monitor cochlear function during insertion of a cochlear implant. METHODS: Intraoperative ECoG recordings were obtained in subjects receiving a cochlear implant from the RW and from just inside scala tympani (n = 26). Stimuli were tones at high levels (80-100 dB HL). Further recordings were obtained during insertions of a temporary lateral cochlear wall electrode (n = 8). Response magnitudes were determined as the sum of the first and second harmonics amplitudes. RESULTS: All subjects had measurable extracochlear responses at the RW. Twenty cases (78%) showed a larger intracochlear response, compared with three (11%) that had a smaller response and three that were unchanged. On average, signal amplitudes increased with increasing electrode insertion depths, with the largest increase between 15 and 20 mm from the RW. CONCLUSION: ECoG to acoustic stimuli via an intracochlear electrode is feasible in standard cochlear implant recipients. The increased signal can improve the speed and efficiency of data collection. The growth of response magnitudes with deeper intrascalar electrode positions could be explained by closer proximity or favorable geometry with respect to residual apical signal generators. Reductions in magnitude may represent unfavorable geometry or cochlear trauma.

Outcomes of intubation in difficult airways due to head and neck pathology.

The purpose of this study was to examine the impact of surgical pathology, anesthesiologist experience, and airway technique on surgically relevant outcomes in patients identified by preoperative laryngoscopy to have a difficult airway due to head and neck pathology. We prospectively recorded a series of 152 difficult airway cases due to head and neck pathology out of 2,145 direct laryngoscopies undertaken between November 2005 and June 2008. One of two senior anesthesiologists specializing in head and neck procedures intubated 101 (66.4%) of the 152 patients and did so 3.3 minutes faster (p = 0.51), with better oxygenation (87.3 vs. 81.8%; p = 0.02) and fewer airway plan changes (p = 0.001) than did other, nonspecialist anesthesiologists. Predictors of failure of the first intubation plan included: cancer diagnosis (p = 0.02), previous radiotherapy (p = 0.03), and supraglottic lesions (p = 0.03). Glottic/subglottic lesions required the most intubation attempts (p = 0.02). Awake fiberoptic intubation was the most common method used (44.7%) but resulted in a change in the airway plan in 6 cases (8.8%). Gas induction maintained the best oxygenation (p = 0.01). Awake tracheostomy was infrequent (1.3%) and took the longest (p = 0.006). We concluded that difficult airways due to head and neck pathology require teamwork and a backup plan. An anesthesiologist specializing in head and neck procedures may help to avoid adverse outcomes associated with cancer, especially previously irradiated supraglottic/glottic lesions, leading to a less frequent need for awake tracheostomy.

Prophylactic neck dissection in early oral tongue squamous cell carcinoma 2.1 to 4.0 mm depth.

OBJECTIVE: Regional recurrence is common following surgery for T1/T2 oral tongue squamous cell carcinoma (SCC). Tumor depth >4.0 mm is commonly assigned as an indication for prophylactic neck dissection to improve regional control. Prophylactic neck dissection may detect extracapsular extension, a poor prognostic sign where adjuvant chemotherapy is indicated. The hypothesis in this study is that regional recurrence is a significant problem in 2.1- to 4.0-mm-depth tumors, and detection of extracapsular extension may be important in this group. STUDY DESIGN: Retrospective chart review. SETTING: Australian tertiary referral center. SUBJECTS AND METHODS: Review of all patients with T1/T2 oral tongue SCC treated surgically between January 1991 and January 2009 (n = 81). RESULTS: Twenty-nine prophylactic and 5 therapeutic neck dissections followed for a median 34 months (range, 4-132 months). Tumor depths were 0 to 2.0 mm (n = 15), 2.1 to 4.0 mm (n = 18), 4.1 to 7.0 mm (n = 26), and >7.0 mm (n = 22). Tumors 2.1 to 4.0 mm depth had similar rates of occult nodes as 4.1 to 7.0 mm depth (25% vs 20%). Regional recurrence occurred in 31% overall, 44% in tumors 2.1 to 4.0 mm, and 27% in tumors 4.1 to 7.0 mm depth. Prophylactic neck dissection reduced regional recurrence (17% vs 43%, P = .02). Patients with pathologically negative necks had lower rates of regional recurrence than those with occult nodes (9% vs 50%, P < .01). Extracapsular extension increased regional recurrence (43% vs 7%, P = .02), including 25% of dissected necks with tumor depth 2.1 to 4.0 mm. CONCLUSIONS: Regional recurrence is a significant problem in 2.1- to 4.0-mm-depth T1/T2 tongue tumors. Prophylactic neck dissection may improve regional control in patients with adequate primary resection margins and determine need for adjuvant therapies in 2.1- to 4.0-mm-depth tumors.

Functional outcomes of fibula and osteocutaneous forearm free flap reconstruction for segmental mandibular defects.

OBJECTIVE/HYPOTHESIS: To demonstrate that the osteocutaneous radial forearm free flap provides equivalent functional outcomes and improved morbidity compared to the fibular free flap in mandibular reconstruction. STUDY DESIGN: Retrospective review. METHODS: There were 168 patients requiring free flap reconstruction of segmental mandibular defects between January 2001 and December 2008. Mean follow-up was 31 months for fibula free flap (FFF) (n = 117) and 20 months for osteocutaneous radial forearm free flaps (OCRFFF) (n = 51), reflecting an increasing use of forearms. RESULTS: OCRFFF were more commonly used in older patients (mean 63.7 years vs. 59 years, P = .03). The majority (96.2%) of reconstruction was for malignant pathology. Flap failure was 3.4% for the fibula group and 3.9% in the forearm group. Malunion was infrequent (2.0% OCRFFF, 6.0% FFF, P = .26). Donor site complications were higher in the FFF group (4.3%) versus none in the OCRFF group (P = .13). Despite a high rate of long-term survival in this patient population (75% at 5 years for carcinoma), dental implants were rarely placed (2.3% of patients) and were more common in forearm than fibula free flaps. Functional outcomes demonstrated no significant difference between groups with respect to oral diet (FFF 72.6% vs. OCRFFF 79.1%, P = .49) or retained enterogastric feeding tube (20.9% OCRFFF vs. 27.4% FFF, P = .49). CONCLUSIONS: Osteocutaneous radial forearm flaps provide comparable functional outcomes with less morbidity compared to fibula free flaps for selected segmental mandibulectomy defects. The overall dental implantation rate was low and more commonly performed in osteocutaneous radial forearm flaps compared to fibula flaps.

Outcomes of static and dynamic facial nerve repair in head and neck cancer.

OBJECTIVES/HYPOTHESIS: Determine outcomes associated with nerve grafting versus static repair following facial nerve resection. STUDY DESIGN: Retrospective chart review. METHODS: Charts from 105 patients who underwent facial nerve reconstruction between January 1999 and January 2009 were reviewed. The majority had parotid malignancy (78.1%), most commonly squamous cell carcinoma (50.5%). Patients underwent static (n = 72) or dynamic (n = 33) reconstruction with nerve grafting. Facial nerve function was measured using the House-Brackmann (H-B) scale. RESULTS: Patients receiving static reconstruction were on average 10.3 years older (P = .002). Mean overall survival for tumor cases was 61.9 months; parotid squamous cell carcinoma was associated with worse prognosis (P = .10). Median follow-up was 16.1 months (range, 4-96.1 months). Most (97%) patients receiving a nerve graft had some return of function at a median of 6.2 months postoperatively (range, 4-9 months) and the majority (63.6%) had good function (H-B score 6 cm), and prolonged preoperative dysfunction.