Long-term outcomes of endolymphatic sac shunting with local steroids for Meniere's disease.

OBJECTIVES: To evaluate the long-term efficacy of endolymphatic sac shunt techniques with and without local steroid administration. STUDY DESIGN: Retrospective case series and patient survey. SETTING: Tertiary university hospital. PATIENTS: Meniere's disease (MD) patients that failed medical therapy and subsequently underwent an endolymphatic sac shunt procedure. All patients had definitive or probable MD and at least 18-months of follow-up. INTERVENTIONS: Three variations on endolymphatic sac decompression with shunt placement were performed: Group A received no local steroids, Group B received intratympanic dexamethasone prior to incision, and Group C received dexamethasone via both intratympanic injection and direct endolymphatic sac instillation. MAIN OUTCOME MEASURE(S): Vertigo control, hearing results, and survey responses. RESULTS: Between 2002 and 2013, 124 patients with MD underwent endolymphatic sac decompression with shunt placement. 53 patients met inclusion criteria. Groups A, B, and C had 6 patients, 20 patients, and 27 patients, respectively. Mean follow-up was 56months. Vertigo control improved in 66%, 83%, and 93% of Groups A, B, and C. Functional level improved for Group B (-2.0) and Group C (-2.2) but was unchanged in Group A. Pure-tone average and speech discrimination scores changed by +22dB and -30%, +6dB and -13%, and +6dB and -5% in Groups A, B, and C. The long-term hearing results were significantly better with steroids (Groups B and C) according to the AAO-HNS 1995 criteria but did not meet significance on non-parametric testing. CONCLUSIONS: Endolymphatic sac shunt procedures may benefit from steroid instillation at the time of shunt placement.

Successful endovascular management of venous sinus thrombosis complicating trans-labyrinthine removal of vestibular schwanomma.

Cerebral venous sinus thrombosis (CVST) is a rare complication of surgical treatment of vestibular schwanomma. We present a rare case of extensive venous sinus thrombosis after trans-labyrinthine approach that was refractory to systemic anti-coagulation. Mechanical aspiration thrombectomy was utilized to re-canalize the venous sinuses and resulted in successful resolution of neurological symptoms. Indications of utilizing endovascular approaches are discussed that will enable skull base surgeons to address this uncommon yet potentially fatal complication.

Ipsilateral single stage conversion from BAHA to cochlear implant.

Profound unilateral sensorineural hearing loss is an indication for the placement of a bone anchored hearing aid. In a few unfortunate patients who later develop contralateral hearing loss, a cochlear implant becomes a good option. We present our experience in these cases and discuss our technique for single stage conversion from a bone anchored hearing aid to a cochlear implant.

Predictive factors and outcomes of cochlear implantation in patients with connexin 26 mutation: a comparative study.

PURPOSE: To compare hearing outcomes in patients with connexin 26 (Cx 26) mutations undergoing cochlear implantation to age matched controls and to examine whether age at implantation, gender and type of mutation were correlated with hearing outcome. MATERIALS AND METHODS: Retrospective chart review of 21 patients with Cx 26 mutations that underwent cochlear implantation compared to 18 age-matched controls. Patients' characteristics, type of mutation and pre- and postoperative short and long-term hearing thresholds, word and sentence scores were analyzed. RESULTS: There was no statistically significant difference between the Cx 26 and control group in the mean short term and mean long term post-operative pure tone averages (PTA), speech reception thresholds (SRT), word and sentence scores. Gender, age at implantation and type of connexin 26 mutation did not predict hearing outcomes. CONCLUSIONS: In patients with connexin 26 mutation, cochlear implantation provides an effective mean of auditory habilitation. Mutational status, age and gender do not seem to predict hearing outcomes.

Hearing and vertigo outcomes after congenital labyrinthine cholesteatoma resection.

Congenital labyrinthine cholesteatoma can cause varying degrees of hearing loss and vertigo. Hearing preservation is not always possible when treatment involves total labyrinthectomy. Since 1969, there have been several case reports and case series documenting hearing preservation following surgical treatment of congenital labyrinthine cholesteatoma. However, none of the case reports or case series documents the patients' vestibular complaints after surgery. Herein, we report a case series of four patients who were treated with the goal of hearing preservation and resolution of vertigo after partial or complete removal of the bony labyrinth for congenital inner ear cholesteatoma. We will also discuss possible explanations for the mechanisms of preservation of hearing and vestibular function with a review of the current literature.

Meningoencephalocele of the temporal bone: pictorial essay on transmastoid extradural-intracranial repair.

PURPOSE: A spontaneous meningoencephalocele of the temporal bone may present with effusion in the middle ear, a cerebrospinal fluid leak, hearing loss, or rarely otitic meningitis. Repair of spontaneous encephaloceles in the temporal bone has been performed using transmastoid and transcranial middle fossa approaches or a combination of the two with varied results. The authors present a technical paper on the transmastoid extradural intracranial approach for the management of temporal lobe encephaloceles. MATERIALS/METHODS: Case reports and cadaver dissections are used to provide a pictorial essay on the technique. Advantages and disadvantages compared with alternative surgical approaches are discussed. RESULTS: Traditional transmastoid approaches are less morbid compared with a transcranial repair as they avoid brain retraction. However, in the past, there has been a higher risk of graft failure and hearing loss due to downward graft migration and a potential need for ossicular disarticulation. For the appropriate lesion, the transmastoid extradural intracranial approach lesion offers a stable meningoencephalocele repair without the comorbidity of brain retraction. CONCLUSION: The authors describe a transmastoid extradural intracranial technique via case reports and cadaver dissections for the repair of spontaneous meningoencephalocele defects larger than 2 cm. This approach provides more support to the graft compared to the conventional transmastoid repair.

Surgical duration of cochlear implantation in an academic university-based practice.

OBJECTIVE: Establish the time to safely and efficiently perform cochlear implantation (CI) in a university-based academic center. STUDY DESIGN: Case series with chart review. SETTING: Academic neurotologic referral center. PATIENTS: 424 patients who underwent CI surgery between 2002 and 2010. INTERVENTION: Unilateral, bilateral or revision CI using commercially available devices approved for use in the United States. MAIN OUTCOME MEASURES: mean surgical duration (SD) and mean total operative room time (TORT). RESULTS: Overall mean SD for all 424 patients was 83 ± 30 min (min) whereas the mean TORT was 135 ± 56 min. The mean SD for unilateral CI was 84 ± 18 min for the first implant and 82 ± 22 min for the second implant (p=0.55). The SD for primary and revision CI was 83 ± 18 min and 85 ± 36 min, respectively (p=0.51). The mean SD for pediatric and adult CI was 83 ± 21 min and 83 ± 18 min, respectively (p=0.92). The mean SD without resident assistance was 74 ± 14 min whereas with the assistance of a resident the mean SD was 84 ± 20 min (p=0.02). When ossification was encountered the mean SD was 90 ± 32 min compared to 82 ± 19 min when absent (p<0.001). An association was found between TORT or SD, and the year of surgery, presence of ossification and the involvement of an assistant. CONCLUSION: In a university-based academic center, CI surgery can be safely and efficiently performed, supporting future cost-effectiveness analysis of its current practice.

Cochlear implantation outcomes in patients with far advanced otosclerosis.

OBJECTIVES: To compare hearing outcomes in patients with far advanced otosclerosis (FAO) undergoing cochlear implantation to an age-matched group of controls, to describe the effects of cochlear ossification on hearing, and to review the adverse effects of implantation in patients with FAO. HYPOTHESIS: Hearing performance in patients with FAO after cochlear implantation is comparable to similarly treated postlingually deafened adults without FAO. Ossification or retrofenestral otosclerosis does not predict poor hearing outcomes. Modiolar-hugging technology reduces postoperative facial nerve stimulation. STUDY DESIGN: Retrospective chart review. SETTING: Academic neurotologic tertiary referral center. PATIENTS: Thirty patients with FAO, who metaudiological criteria for cochlear implantation, were compared to 30 age-matched controls, postlingually deafened by non-otosclerotic causes. MAIN OUTCOME MEASURES: Audiometric pre- and postoperative speech reception threshold, word, and sentence scores were analyzed. The presence of retrofenestral findings on computed tomography or intraoperative cochlear ossification were noted. RESULTS: In the FAO group, radiographic abnormalities were noted in 26.4% of patients. Intraoperative ossification requiring drillout was seen in 29.4% of patients. None developed postoperative facial nerve stimulation. There was no difference between the FAO and control groups in the mean short-term and long-term postoperative speech reception threshold, word, and sentence scores (P = .77). The presence of radiographic abnormalities did not predict hearing outcome. Intraoperative cochlear ossification was not associated with worse short-term word and sentence scores (P = .58 and 0.79, respectively), and for the long-term hearing outcome (P = .24). CONCLUSIONS: In patients with FAO, effective and safe hearing rehabilitation can be accomplished with cochlear implantation.

Cochlear Implantation in Patients With Menière's Disease: Does Disease Activity Affect the Outcome?

OBJECTIVE: Menière's disease (MD) is characterized by episodes of vertigo, tinnitus, and sensorineural hearing loss. In the setting of bilateral deafness due to MD alone or contralateral pathology, cochlear implantation (CI) improves hearing. Active MD is characterized by fluctuating auditory symptoms and vertigo; whereas remittance of vertiginous symptoms and severe, permanent sensorineural hearing loss characterizes the inactive disease state. This study evaluates outcomes for MD patients compared with the general CI population and assesses if disease activity affects implant outcomes. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Twenty-four patients with MD that received CI (7 active, 16 inactive, and 1 Probable Menière's), and 24 age-matched controls. INTERVENTIONS: Cochlear implantation. MAIN OUTCOME MEASURES: Word Recognition Score, Sentence Recognition Score (SRS), and Speech Reception Threshold. RESULTS: Best-aided preoperative and postoperative audiometric data were compared per ear between MD patients and controls and stratified by disease status using descriptive statistics with mixed-effects modeling. Patients with MD derived significantly more benefit from CI than controls when comparing differences between preoperative and postoperative levels for Word Recognition Score (12.2%, p = 0.0236), SRS (12.8%, p = 0.0375), and Speech Reception Threshold (-14.4 dB, p = 0.0188). Active disease status does not negatively impact CI outcomes and patients with active MD may benefit from greater gains in SRS (23.5%, p = 0.0107). CONCLUSIONS: CI provides greater gains in functional hearing for patients with MD compared with age-matched controls. Patients with active MD seem to perform better with respect to SRS following CI than patients with inactive status.

The medial wall of the jugular foramen: a temporal bone anatomic study.

OBJECTIVE: To better understand the variable and complex anatomy of the jugular foramen (JF) and the relationship between the neurovascular structures in the medial wall of the jugular bulb (JB). STUDY DESIGN: A temporal bone anatomic study. SETTING: A temporal bone laboratory within a hearing research facility. SUBJECTS AND METHODS: Twenty-two temporal bones were dissected under the operating microscope. The JF anatomy was exposed by using the modified infratemporal fossa approach (no rerouting of the facial nerve). Pictures were taken at various intervals during the dissection. Distances between important structures were measured with two-point calipers and transferred to a millimetric scale. RESULTS: The right JF was found to be larger than the left side in 72.7 percent of the dissected temporal bones. A fibrous septum separated the glossopharyngeal (CN IX) from the vagus (CN X) and accessory (CN XI) nerves in 19 specimens (86.4%), and a complete bony septum was present in three specimens (13.6%). The CNs IX, X, and XI traveled anteromedially to the JB within the JF. The inferior petrosal sinus (IPS) drained into the medial wall of the JB at various locations by two or more channels. In most of the specimens (86.4%), the IPS separated CNs IX and X. CONCLUSION: The lower cranial nerves have an intimate relationship to the medial wall of the JB. Within the JF, the neurovascular structures vary in size, shape, and location. To minimize surgical morbidity, the surgeon should be familiar with the complex anatomy of the JB and its variations.

A mouse model with postnatal endolymphatic hydrops and hearing loss.

Endolymphatic hydrops (ELH), hearing loss and neuronal degeneration occur together in a variety of clinically significant disorders, including Meniere's disease (MD). However, the sequence of these pathological changes and their relationship to each other are not well understood. In this regard, an animal model that spontaneously develops these features postnatally would be useful for research purposes. A search for such a model led us to the Phex Hyp-Duk mouse, a mutant allele of the Phex gene causing X-linked hypophosphatemic rickets. The hemizygous male (Phex Hyp-Duk/Y) was previously reported to exhibit various abnormalities during adulthood, including thickening of bone, ELH and hearing loss. The reported inner-ear phenotype was suggestive of progressive pathology and spontaneous development of ELH postnatally, but not conclusive. The main focuses of this report are to further characterize the inner ear phenotype in Phex Hyp-Duk/Y mice and to test the hypotheses that (a) the Phex Hyp-Duk/Y mouse develops ELH and hearing loss postnatally, and (b) the development of ELH in the Phex Hyp-Duk/Y mouse is associated with obstruction of the endolymphatic duct (ED) due to thickening of the surrounding bone. Auditory brainstem response (ABR) recordings at various times points and histological analysis of representative temporal bones reveal that Phex Hyp-Duk/Y mice typically develop adult onset, asymmetric, progressive hearing loss closely followed by the onset of ELH. ABR and histological data show that functional degeneration precedes structural degeneration. The major degenerative correlate of hearing loss and ELH in the mutants is the primary loss of spiral ganglion cells. Further, Phex Hyp-Duk/Y mice develop ELH without evidence of ED obstruction, supporting the idea that ELH can be induced by a mechanism other than the blockade of longitudinal flow of endolymphatic fluid, and occlusion of ED is not a prerequisite for the development of ELH in patients.

Temporal bone fracture: evaluation and management in the modern era.

Temporal bone fractures occur from high-energy mechanisms, typically but not limited to motor vehicle accidents. However, as the automotive industry continues to introduce improved safety measures, violence and falls account for a larger proportion of cases. Given the great forces involved, temporal bone fractures rarely occur in isolation and initial evaluation must focus on the fundamental ABCs of Advanced Trauma Life Support with special attention to Glasgow Coma Scale, intracranial injury, and cervical spine injury. Subsequent evaluation relies on physical examination, high-resolution CT, and electrodiagnostic testing to address the neurotologic consequences of temporal bone fracture, including cerebrospinal fluid leak, facial nerve injury, and injury to the peripheral hearing and balance organs. Management algorithms must address immediate (eg, ABCs, neurosurgical issues), short-term (eg, cerebrospinal fluid leak, facial nerve injury, hearing loss), long-term (eg, facial nerve injury, hearing loss, vestibular injury), and delayed (eg, encephalocele, cholesteatoma, late meningitis) issues. This article reviews the current state of temporal bone fracture evaluation and management with special attention to mechanisms of injury, clinical presentations and emergency evaluation, and diagnostic workup, including the evolution of radiographic fracture classification systems and electrodiagnostic testing. Discussion of treatment approaches address management of immediate, short-term, long-term, and delayed complications.

Optimization of ribonucleic acid detection from archival Guinea pig temporal bone specimens.

HYPOTHESIS: The choice of ribonucleic acid (RNA) isolation protocol coupled with modifications to RNA extraction and detection procedures may result in a more reliable method to detect gene expression in archived temporal bones. BACKGROUND: A large number of archival temporal bones exist. Retrospective analysis of these specimens using techniques of RNA extraction will greatly enrich our understanding of the pathophysiology of specific otologic diseases. However, archival human temporal bones are aged and embedded in paraffin or celloidin, rendering isolation and manipulation of nucleic acid in preserved specimens difficult, especially as it pertains to RNA degradation. Despite some reports of moderate success in the recent past, RNA isolation and gene expression using polymerase chain reaction (PCR) analysis continues to be challenging and unreliable. Archival guinea pig temporal bone specimens were used to develop and optimize a protocol for RNA extraction and gene expression analysis using PCR and quantitative PCR methods. The genes amplified comprise housekeeping genes and genes associated with the glutamate pathway. METHODS: Archival celloidin-embedded guinea pig temporal bones were collected from the senior author's collection of experimental hydropic inner ear specimens. RNA from this tissue was extracted using the protocol described previously in 16animals and using a modified trizol extraction technique in 10 animals. Gene expression analysis was performed on the extracted RNA. Analysis included two housekeeping genes, GAPDH and 18S, as well as three mediators of the glutamate pathway, glutamate aspartate transporter, glutamate synthetase, and inducible nitric oxide synthase. RESULTS: Compared with the standard extraction protocol, the trizol-based extraction technique showed greater reliability and reproducibility of RNA detection. The housekeeping gene GAPDH or 18S was detected in 7 of 36 attempts with the standard protocol versus 9 of 9 using the modified extraction method (P < 0.001). The gene of interest, glutamate aspartate transporter, was detected in 3 of 26 attempts with the standard protocol versus 12 of 13 attempts using the modified extraction method (P < 0.001). Quantification of messenger RNA levels was then achieved using quantitative PCR methods. CONCLUSION: Improved reliability for detection of gene expression and demonstration of reproducibility were accomplished by modification of RNA extraction technique and standard reverse transcriptase PCR protocol. In addition, we also showed that gene expression from archival material can be quantified by real-time PCR.

Evaluation and management of endolymphatic sac and duct tumors.

The endolymphatic sac tumor is a slow-growing, locally aggressive neoplasm that originates from the epithelium of the endolymphatic sac and duct. Disease progression can lead to profound sensorineural hearing loss, posterior fossa invasion, brainstem compression, drop metastasis, and eventual death. Early diagnosis and surgical attention are the primary objectives in the management of patients who have endolymphatic sac tumor. This article describes the latest rationale and techniques for hearing preservation surgery and a review of the latest developments surrounding this disease entity.

Endolymphatic duct status during middle fossa dissection of the internal auditory canal: a human temporal bone radiographic study.

OBJECTIVE: Successful hearing preservation after acoustic neuroma resection is sometimes complicated by delayed hearing deterioration. The middle fossa approach appears to offer superior long-term hearing results when compared to the retrosigmoid surgical approach. The goal of this study is to investigate the hypothesis that internal auditory canal (IAC) drilling during middle fossa acoustic neuroma removal is associated with a lower incidence of endolymphatic duct (ELD) injury, a potential cause of delayed hearing loss (HL) known to accompany retrosigmoid hearing preservation dissection techniques. STUDY DESIGN: A human temporal bone anatomic and radiographic study complemented with a literature review. METHODS: Twenty human temporal bones were analyzed with high-resolution multislice computed tomography (HRMCT) and subjected to standard extended middle fossa IAC dissection with labyrinthine preservation and follow-up HRMCT for analyses of the ELD. RESULTS: Zero of 20 (0%) temporal bones were found to have violation of the ELD with preservation of the labyrinthine structures and the endolymphatic sac. Reviews of human and animal studies indicate that injury to the ELD may create endolymphatic hydrops, a known cause of hearing deterioration. CONCLUSION: The ELD is not vulnerable to injury during IAC dissection using the middle fossa approach. A previous radiographic study has shown that the ELD is violated in 24% of temporal bones during retrosigmoid dissection of the IAC. These findings support and may help explain other outcome studies that show that long-term hearing results are superior with the use of the middle fossa approach when compared to results following retrosigmoid dissection.

Tissue-engineered calcium alginate patches in the repair of chronic chinchilla tympanic membrane perforations.

OBJECTIVE: Chronic tympanic membrane perforations are a common problem in the United States. A high number of these cases results from placement of pressure equalization tubes. These perforations may initially be treated with paper patch techniques and although safe and well tolerated, the procedure demonstrates poor efficacy. The ideal treatment for small perforations should be rapid, minimally invasive, and efficacious. Calcium alginate-based tissue engineered tympanic membrane patches represent an attractive option, but in vivo data are required. METHODS: A controlled prospective study of tympanic membrane perforation repair using a well-known chinchilla model of chronic tympanic membrane perforation was performed. Calcium alginate-based tympanic membrane patches were created using computer-aided design techniques. A previously described chinchilla model of chronic tympanic membrane perforations was used to create stable perforations ranging from 2 to 5 mm. Ears with chronic perforations were divided into three groups: control (no patch), paper patch, and calcium alginate plugs. At 10 weeks postimplantation, all animals were killed and inspected both grossly and histologically for healing. RESULTS: In the chinchilla model, the alginate grafts demonstrated significantly improved healing rates over both the untreated control group (spontaneous repair) and the paper patch group; nine of 13 healed in the alginate group versus two of nine healed in the paper patch group (P < .05) versus one of 11 healed in the control group (P < .05). CONCLUSION: Calcium alginate tympanic membrane perforation patches offer a significant advantage in the repair of chronic perforations over traditional techniques in the chinchilla perforation model and may offer attractive opportunities in the clinical setting.

The pathophysiology of cholesteatoma.

The pathogenesis of middle ear cholesteatoma continues to be highly debated. In recent years, there has been a substantial improvement in the understanding of the pathophysiology of this disease. This chapter provides a summary of the history and evolution of cholesteatoma and a review of the recent literature that pertains to the pathophysiology of congenital and acquired cholesteatoma. An emphasis is placed on the mechanism of osteolysis and the factors predictive of aggressiveness and recidivism.

Bilateral Sequential Cochlear Implantation in Patients With Enlarged Vestibular Aqueduct (EVA) Syndrome.

OBJECTIVES: To analyze audiometric outcomes after bilateral cochlear implantation in patients with isolated enlarged vestibular aqueduct (EVA) syndrome and associated incomplete partition (IP) malformations. Secondary objective was to analyze rate of cerebrospinal fluid (CSF) gusher in patients with IP-EVA spectrum deformities and compare this with the existing literature. STUDY DESIGN: Retrospective chart review. METHODS: Thirty-two patients with EVA syndrome who received unilateral or bilateral cochlear implants between June 1999 and January 2014 were identified in the University Hospitals Case Medical Center cochlear implant database. Isolated EVA (IEVA) and Incomplete Partition Type II (IP-II) malformations were identified by reviewing high-resolution computed tomography (HRCT) imaging. Demographic information, age at implantation, surgical details, postimplantation audiometric data including speech reception thresholds (SRT), word, and sentence scores were reviewed and analyzed. Intra- and postoperative complications were analyzed as well and compared with the literature. RESULTS: Seventeen patients (32 implanted ears) had pediatric cochlear implantation for EVA-associated hearing loss. Data from 16 controls (32 implanted ears) were used to compare audiometric and speech outcomes of EVA cohort. Mean age at implantation was 6.8 years for EVA cohort and 6.0 years for controls. There was no statistically significant difference in long-term postoperative SRT, monaurally aided word scores, and binaurally tested word scores between pediatric EVA group and controls. The EVA patients had a long-term mean sentence score of 85.92%. A subset of EVA patients implanted at mean age of 3.18 years (n = 15 ears) had similar audiometric outcomes to another control group with Connexin 26 mutations (n = 20 ears) implanted at a similar age. Further subset analysis revealed no significant differences in age at implantation, SRT, and word scores in patients with IEVA and IP-II malformation. There was no significant association between size of vestibular aqueduct and age at implantation. There was no CSF gusher or other intra- or postoperative complications reported in our series. CONCLUSION: Bilateral sequential cochlear implantation can be performed safely in patients with EVA. Audiometric outcomes are excellent and comparable to pediatric cochlear implant patients with no malformations. CSF gusher rates can be minimized by trans-round window approach. Further long-term studies are needed to identify differences within IP-EVA spectrum deformities, audiometric outcomes, and proportions of EVA patients who will need cochlear implantation for hearing rehabilitation.

Retrosigmoid versus translabyrinthine approach to acoustic neuroma resection: A comparative cost-effectiveness analysis.

OBJECTIVES/HYPOTHESIS: Approach-specific economic data of acoustic neuroma (AN) resection is lacking. The purpose of this study was to analyze and compare adjusted total hospital costs, hospital and intensive care unit (ICU) length of stay (LOS), and associated factors in AN patients undergoing resection by translabyrinthine (TL) approach versus retrosigmoid (RS) approach. STUDY DESIGN: Retrospective chart review. METHODS: A total of 113 patients with AN undergoing TL (N = 43) or RS (N = 70) surgical resection between 1999 and 2012 were analyzed. Data including age, health status, preoperative hearing, tumor size, postoperative complications, hospital, ICU LOS, and disposition after discharge were collected from medical records and compared between both groups. Cost data was obtained from the hospital finance department and adjusted based on the Consumer Price Index for 2013. RESULTS: There were no significant differences in demographic data, preoperative hearing, preoperative health status, or postoperative complication rate. Total hospital LOS and ICU LOS were significantly longer in the RS compared to the TL group (4.3 ± 3.6 vs. 2.6 ± 1.1 days; P < 0.001, and 1.5 ± 1.1 vs. 1.0 ± 0.5 days; P = 0.015, respectively). Tumors were larger in RS compared to the TL group (2.1 ± 1.0 cm vs. 1.5 ± 0.7 cm, respectively; P = 0.002). When patients were stratified by tumor size < or ≥ 2 cm, the total hospital LOS remained greater in the RS group in both subgroups (< and ≥ 2 cm, P < 0.001, and P = 0.031, respectively). However, there was no difference in the total ICU LOS between both subgroups. The adjusted mean total hospital cost was higher in the RS compared to the TL group ($25,069 ± 14,968 vs. $16,799 ± 5,724; P < 0.001). The adjusted mean total hospital cost was greater in the RS group with tumor < 2 cm (P < 0.001) but not significantly different in patients with tumors ≥ 2 cm. Univariate analysis showed that greater tumor size, poorer preoperative health status, the presence of major postoperative complications, and the RS approach were independently significantly associated with higher total hospital LOS (P = 0.001, P = 0.009, P = 0.001, and P < 0.001, respectively) and a higher adjusted total hospital cost (P < 0.001, P = 0.002, P = 0.014, and P < 0.001, respectively). CONCLUSION: Hospital LOS and total adjusted costs are significantly less for patients undergoing translabyrinthine acoustic neuroma resection compared to the retrosigmoid approach. Many factors appear to influence these differences. Economic considerations in addition to tumor characteristics and surgeon preference should be considered in future acoustic neuroma resections. LEVEL OF EVIDENCE: 2c.

The basic science of Meniere's disease and endolymphatic hydrops.

PURPOSE OF REVIEW: Meniere's disease is characterized by the triad of fluctuating hearing loss, episodic vertigo, and tinnitus and by endolymphatic hydrops found on post-mortem examination. The cause of Meniere's disease remains unclear. Numerous factors play a role in the development of hydrops and in the pathogenesis of related cochleovestibular dysfunction. This review highlights recent advances in the understanding of the pathophysiology of symptom development in Meniere's disease by detailing the role of genetics, autoimmunity, endolymphatic fluid homeostasis, excitotoxicity, oxidative stress, and cellular apoptosis. Emphasis is placed on reviewing the newly described animal models that exhibit endolymphatic hydrops. RECENT FINDINGS: Recent evidence suggests that hearing loss might be explained in part by apoptosis of spiral ganglion neurons and that hydrops could represent an epiphenomenon rather than an initiating factor. In addition, the accepted guinea pig model described by Kimura has certain limitations. An animal model that would supplement and in some cases replace the surgically induced model is currently being sought. SUMMARY: These recent advances have expanded our understanding and will allow for the development of targeted therapeutic interventions aimed at preventing the progression oochleovestibular deterioration.