Canalplasty for Exostoses With Maximal Skin Preservation With Temporoparietal Fascia Grafting and Use of Bone Wax for Skin Flap Protection: A Retrospective Case Series.

BACKGROUND: External auditory canal exostoses are benign, bony overgrowths that arise in patients who experience chronic cold water exposure. While considerable advancement has been made in canalplasty techniques in recent decades, many patients continue to experience prolonged healing periods and recurrent stenosis following surgery. OBJECTIVE: To perform a retrospective outcomes analysis of our experience with a skin-preserving canalplasty technique with temporoparietal fascia grafting and use of bone wax for skin flap protection. STUDY DESIGN: Retrospective review. SUBJECTS AND METHODS: Thirty-four patients (41 ears) underwent canalplasty from 2008 to 2014 at a tertiary referral center. Primary outcome measures included rates of prolonged healing and restenosis, need for revision surgery, and audiometric results. Rates of intraoperative and postoperative complications were also tabulated. RESULTS: No patient experienced recurrent stenosis or required a revision surgery within the follow-up period. All but one patient (97%) achieved complete healing within 8 weeks. Minimal intraoperative complications were found. Statistically significant improvements in air pure tone averages and air-bone gaps were achieved. CONCLUSION: The proposed technique is a safe and effective method of canalplasty for exostoses that imparts accelerated wound healing and minimizes the rate of recurrent stenosis.

Vestibular Schwannoma Cerebellopontine Angle Position Impacts Facial Outcome.

OBJECTIVES/HYPOTHESIS: To determine the impact of vestibular schwannoma (VS) position relative to the internal auditory canal (IAC) on postoperative facial nerve function and extent of surgical resection. STUDY DESIGN: Retrospective chart review. METHODS: Retrospective review of patients undergoing resection of large (≥25 mm) VSs. Outcome measures included early (≤1 month) facial function, long-term (≥1 year) facial function and extent of resection. Tumor measurements included the greatest dimension, dimension anterior to the IAC axis, dimension posterior to the IAC axis, and a ratio of posterior-to-anterior dimension (PA ratio). RESULTS: A total of 127 patients met inclusion criteria. In early follow-up, 60% patients had good (House-Brackmann I-II), and 40% patients had poor (House-Brackmann III-VI) facial function. In long-term follow-up, 71% patients had good, and 29% patients had poor facial function. A total of 72% of patients underwent gross total resection (GTR) of their tumors. Patients with good facial function had significantly larger PA ratios than patients with poor function both early and long term; however, greatest dimension was the more clearly significant independent predictor of facial outcomes. A larger PA ratio was observed in patients in whom GTR was achieved, but this association was potentially confounded by surgeon preferences and was not statistically significant after controlling for surgical site. CONCLUSIONS: This study demonstrates that VS position relative to the IAC axis can be used along with tumor size to predict postoperative facial outcomes. A greater proportion of tumor posterior to the IAC axis was associated with significantly better facial outcomes. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:1093-1098, 2022.

Audiometric Outcomes Following Transmastoid and Middle Cranial Fossa Approaches for Repair of Cerebrospinal Fluid Otorrhea.

OBJECTIVE: Describe audiometric outcomes following transmastoid and middle cranial fossa (MCF) approaches for repair of cerebrospinal fluid (CSF) otorhinorrhea. STUDY DESIGN: Retrospective case series. SETTING: Tertiary skull base referral center. PATIENTS: Adult patients presenting with CSF otorhinorrhea undergoing operative repair between January 2009 and July 2019. INTERVENTION: Transmastoid repair, MCF repair, or a combined approach. MAIN OUTCOME MEASURES: Primary outcome measures included preoperative and postoperative four-frequency pure-tone average (PTA), air-bone gap (ABG) and word recognition score. Secondary outcomes included success of repair, recurrence of CSF leak, and length of stay. RESULTS: Twenty-nine patients underwent 32 operations (mean age 52 yr, 75.9% female). Twenty (62.5%) patients underwent transmastoid repair, while 8 (25%) underwent an MCF approach. Patients had significant postoperative improvement in both PTA (34.8 dB preop vs. 24.5 dB postop, p = 0.003) and ABG (20.2 dB preop vs. 8.6 dB postop, p  = 0.0001). CSF leak recurred in 3 patients (9.4%) over 17-month follow-up. Compared to MCF or combined approaches, transmastoid repair was associated with greater improvement in PTA (15.6 vs. 3.0 dB, p = 0.001) and shorter length of stay (0.3 vs. 1.2 days, p = 0.005). On subset analysis, patients with spontaneous CSF leaks, a single skull base defect, or meningoencephaloceles demonstrated significant audiometric improvements. CONCLUSIONS: The transmastoid approach for repair of CSF otorhinorrhea is effective, safe, and can be done on an outpatient basis. Patients with spontaneous CSF leaks, a single skull base defect, and associated encephaloceles may have better audiometric outcomes.

Preoperative Radiographic Predictors of Hearing Preservation After Retrosigmoid Resection of Vestibular Schwannomas.

OBJECTIVE: To identify preoperative radiographic predictors of hearing preservation (HP) after retrosigmoid resection of vestibular schwannomas (VSs). STUDY DESIGN: Retrospective case series with chart review. SETTING: Tertiary skull base referral center. METHODS: Adult patients with VSs <3 cm and word recognition scores (WRSs) ≥50% who underwent retrosigmoid resection and attempted HP between February 2008 and December 2018 were identified. Pure tone average (PTA), WRS, and magnetic resonance imaging radiographic data, including tumor diameter and dimensional extension relative to the internal auditory canal (IAC), were examined. RESULTS: A total of 151 patients were included. The average tumor size was 13.8 mm (range, 3-28). Hearing was preserved in 41.7% (n = 63). HP rates were higher for intracanalicular tumors than tumors with cerebellopontine angle (CPA) components (57.6% vs 29.4%, P = .03). On multivariate analysis, maximal tumor diameter (odds ratio [OR], 0.892; P < .001) and preoperative PTA (OR, 0.974; P = .026) predicted HP, while mediolateral tumor diameter predicted postoperative PTA (OR, 1.21; P = .005) and WRS (OR, -1.89; P < .001). For tumors extending into the CPA, younger age (OR, 0.913; P = .012), better preoperative PTA (OR, 0.935; P = .049), smaller posterior tumor extension (OR, 0.862; P = .001), and smaller caudal extension relative to the IAC (OR, 0.844; P = .001) all predicted HP. CONCLUSION: Rates of HP are highest in patients with small intracanalicular VSs and good preoperative hearing. For tumors extending into the CPA, greater posterior and caudal tumor extension relative to the IAC may portend worse hearing outcomes.

Preoperative Sudden Hearing Loss May Predict Hearing Preservation After Retrosigmoid Resection of Vestibular Schwannoma.

OBJECTIVES: Describe the effect of preoperative sudden hearing loss (SHL) on likelihood of hearing preservation (HP) after surgical resection of vestibular schwannoma (VS). STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Adult patients (≥18 years) who underwent retrosigmoid VS resection for HP between February 2008 and December 2018 were reviewed. All patients had preoperative word recognition score (WRS) of at least 50%. Similarly, HP was defined as postoperative WRS of more than or equal to 50%. Regression analysis was used to describe the effect of SHL on HP, accounting for tumor size, and preoperative hearing quality. INTERVENTIONS: All patients underwent retrosigmoid VS resection for HP. MAIN OUTCOME MEASURES: WRS of at least 50%. RESULTS: Of 160 patients who underwent retrosigmoid VS resection during the study period, 153 met inclusion criteria. Mean tumor size was 14.0 (±6) mm. Hearing was preserved in 41.8% (n = 64). Forty patients (26.1%) had a history of preoperative SHL. Among 138 patients (90.2%) in whom the cochlear nerve was anatomically preserved during surgery, HP was achieved in 61.8% of those with SHL (21 of 34) and 41.3% of those without SHL (43 of 104) (p = 0.0480). On univariate and multivariate analysis (accounting for tumor size and preoperative hearing quality), SHL was a significant positive predictor of HP (odds ratio 2.292, p = 0.0407 and odds ratio 2.778, p = 0.0032, respectively). CONCLUSION: In patients with VS and retained serviceable hearing, SHL is an independent predictor of HP after retrosigmoid microsurgical resection when the cochlear nerve is preserved.

Delayed Facial Palsy After Resection of Vestibular Schwannoma: An Analysis of Long-term Facial Nerve Outcomes.

OBJECTIVES: 1) Identify clinical factors associated with delayed facial palsy (DFP) after microsurgical resection of vestibular schwannoma. 2) Determine whether DFP predicts worse facial nerve (FN) outcomes. METHODS: Adult patients (≥18 yrs) who underwent vestibular schwannoma resection between February 2008 and December 2017 were retrospectively reviewed. Postoperative House-Brackmann (HB) FN function was assessed on the day of surgery, daily during patients' inpatient admissions, and at postoperative clinic visits. Follow-up exceeded ≥12 months for all patients. DFP was defined as a decline (≥1 HB grade) in FN function (relative to the preoperative state) occurring between postoperative days 1 and 30. RESULTS: Two hundred ninety-one patients were analyzed. Mean age was 51.5 years (±12.3) and mean tumor size 20.6 mm (±10.8). Immediate FP occurred in 61 (21%) patients, and DFP occurred in 112 (38%) patients. Tumor size was largest in patients with immediate FP (p < 0.0001). On univariate analysis, DFP was associated with better final FN outcomes (OR 0.447, p = 0.0101) compared with immediate FP. Multivariate analysis, however, showed that timing of FP was no longer significant, whereas larger tumor size and preoperative HB2 function predicted worse FN outcomes (OR 2.718, p < 0.0001 and OR 9.196, p = 0.0039, respectively). In patients with DFP, longer time to onset of palsy predicted more favorable FN outcomes. CONCLUSIONS: When accounting for tumor size, the timing of onset of postoperative facial palsy does not predict final FN outcomes. In patients who develop DFP, the longer the interval between surgery and onset of weakness, the better the chances of good long-term FN function.

Predicting Long-Term Facial Nerve Outcomes After Resection of Vestibular Schwannoma.

OBJECTIVES: 1) Describe the effect of tumor size on facial nerve (FN) outcomes after microsurgical resection of vestibular schwannoma (VS).2) Describe the effect of surgical approach, preoperative radiation, and early postoperative facial function on long-term FN outcomes. STUDY DESIGN: Retrospective analysis. SETTING: Tertiary referral center. PATIENTS: Adult (≥18 yr) patients underwent translabyrinthine or retrosigmoid VS resection by a single neurotologist and single neurosurgeon between February 2008 and December 2017. MAIN OUTCOME MEASURES: Long-term FN outcomes (≥12 mo) according to House-Brackmann (HB) grade. RESULTS: During the study period, 350 patients underwent VS resection, of whom 290 met inclusion criteria. Translabyrinthine surgery was performed in 54% (n = 158) and retrosigmoid in 45% (n = 131). One patient underwent a combined approach. Among patients who underwent retrosigmoid approach, none had a tumor more than 30 mm. Gross total resection was achieved in 98% (n = 283). Long-term HB1-2 function was achieved in 90% (n = 261). On univariate analysis, tumor size (per cm increase), history of preoperative radiation, and worse HB score at discharge predicted worse FN function. Multivariate analysis showed that tumor size (per cm increase) and history of radiation were independent predictors of FN function. For patients with tumors less than 30 mm, multivariate analysis of tumor size and surgical approach was performed; tumor size remained predictive of worse FN function (odds ratio [OR] 2.362, p = 0.0035), whereas surgical approach was not significantly predictive (p = 0.7569). CONCLUSION: Tumor size and history of radiation predict long-term FN function after VS resection. When accounting for tumor size, the translabyrinthine and retrosigmoid approaches yield equivalent FN results.

The Effect of Tumor Size on Likelihood of Hearing Preservation After Retrosigmoid Vestibular Schwannoma Resection.

OBJECTIVES: 1) Describe the effect of tumor size on the likelihood of hearing preservation after retrosigmoid approach for resection of vestibular schwannoma (VS).2) Describe the effect of preoperative hearing status on the likelihood of hearing preservation. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Adult (18 years or older) patients underwent retrosigmoid VS resection and postoperative audiometry between 2008 and 2018 and had a preoperative word recognition score (WRS) of at least 50%. Patients with a history of neurofibromatosis 2, radiation, or previous resection were excluded. INTERVENTIONS: All patients underwent retrosigmoid VS resection with attempted hearing preservation. MAIN OUTCOME MEASURES: WRS of at least 50%. RESULTS: Data from 153 patients were analyzed. Mean age was 50.8 (±11.3) years and mean tumor size 14 (±6) mm. Hearing was preserved and lost in 64 (41.8%) and 89 (58.2%) patients, respectively. Hearing preservation rates were higher for intrameatal tumors than for tumors with extrameatal extension (57.6% versus 29.4%, p = 0.0005). On univariate and multivariate regression analysis, tumor size (per mm increase) was a negative predictor of hearing preservation (odds ratio [OR] 0.893, p = 0.0002 and 0.841, p = 0.0005, respectively). Preoperative American Academy of Otolaryngology-Head & Neck Surgery Hearing Class was also predictive of hearing preservation (p = 0.0044). Class A hearing (compared with class B hearing) was the strongest positive risk factor for hearing preservation (OR 3.149, p = 0.0048 and 1.236, p = 0.0005, respectively). CONCLUSION: Small tumor size and preoperative class A hearing are positive predictors of hearing preservation in patients undergoing the retrosigmoid approach for VS resection.

Working Toward Consensus on Sporadic Vestibular Schwannoma Care: A Modified Delphi Study.

OBJECTIVE: To address variance in clinical care surrounding sporadic vestibular schwannoma, a modified Delphi study was performed to establish a general framework to approach vestibular schwannoma care. A multidisciplinary panel of experts was established with deliberate representation from key stakeholder societies. External validity of the final statements was assessed through an online survey of registered attendees of the 8th Quadrennial International Conference on Vestibular Schwannoma. STUDY DESIGN: Modified Delphi method. METHODS: The panel consisted of 16 vestibular schwannoma experts (8 neurotology and 8 neurosurgery) and included delegates representing the AAOHNSF, AANS/CNS tumor section, ISRS, and NASBS. The modified Delphi method encompassed a four-step process, comprised of one prevoting round to establish a list of focus areas and three subsequent voting rounds to successively refine individual statements and establish levels of consensus. Thresholds for achieving moderate consensus, at ≥67% agreement, and strong consensus, at ≥80% agreement, were determined a priori. All voting was performed anonymously via the Qualtrics online survey tool and full participation from all panel members was required before procession to the next voting round. RESULTS: Through the Delphi process, 103 items were developed encompassing hearing preservation (N = 49), tumor control and imaging surveillance (N = 20), preferred treatment (N = 24), operative considerations (N = 4), and complications (N = 6). As a result of item refinement, moderate (4%) or strong (96%) consensus was achieved in all 103 final statements. Seventy-nine conference registrants participated in the online survey to assess external validity. Among these survey respondents, moderate (N = 21, 20%) or strong (N = 73, 71%) consensus was achieved in 94 of 103 (91%) statements, and no consensus was reached in 9 (9%). Of the four items with moderate consensus by the expert panel, one had moderate consensus by the conference participants and three had no consensus. CONCLUSION: This modified Delphi study on sporadic vestibular schwannoma codifies 100% consensus within a multidisciplinary expert panel and is further supported by 91% consensus among an external group of clinicians who regularly provide care for patients with vestibular schwannoma. These final 103 statements address clinically pragmatic items that have direct application to everyday patient care. This document is not intended to define standard of care or drive insurance reimbursement, but rather to provide a general framework to approach vestibular schwannoma care for providers and patients.

Hearing Preservation in Vestibular Schwannoma Surgery.

Modern imaging techniques allow early detection of small vestibular schwannomas (VSs) with minimal or no hearing impairment. While controversy surrounds the management of these tumors, given their benign nature and unpredictable natural history, microsurgical excision is the only modality that offers the opportunity to cure the tumor and preserve hearing. Hearing preservation in VS surgery may be accomplished via the middle fossa or retrosigmoid approaches. Appropriate patient selection and surgical approach is critical in achieving the best hearing outcomes. This article highlights the preoperative assessment, patient selection and prognostic factors, intraoperative monitoring of hearing, and surgical approaches to optimize hearing preservation during VS removal.

Maximizing Exposure of the Internal Auditory Canal Via the Retrosigmoid Approach: An Anatomical, Radiological, and Surgical Study.

OBJECTIVE: The purpose of this study was to identify anatomic landmarks and surgical techniques that maximize bone removal for exposure of the distal internal auditory canal (IAC) to avoid labyrinthine injury during retrosigmoid removal of tumors within the IAC. STUDY DESIGN: Anatomic dissection, radiological assessment and retrospective case series. SETTING: Tertiary referral center. METHODS: On the basis of previously conducted temporal bone anatomic dissections of the temporal bone, the authors performed intraoperative measurement of the undissected distal IAC, performed pre- and postoperative radiological assessment of vestibular schwannoma (VS) patients. The surgical and anatomic information was used to determine the anatomic limits of labyrinth sparing bone dissection and the landmarks most critical to maximal IAC exposure. The authors describe surgical techniques using these data. An edited video of representative surgery highlights important principles. Review of 251 patients requiring IAC bony dissection for tumor removal from January 2005 through October 2017 is described. RESULTS: Achieving complete exposure of the IAC fundus is not possible, without labyrinthine injury, via retrosigmoid approach. Anatomic dissection, intraoperative photography, and postoperative radiographs demonstrate that bone removal within 2 to 3 mm of the fundus is routinely possible. The endolymphatic sac and duct is the optimal landmark for optimizing IAC exposure. CONCLUSION: The course of the endolymphatic sac and duct in the posterior petrous bone is the most important landmark determining the lateral limit of bony removal during IAC exposure for tumor resection. Surgical techniques based on these anatomic findings facilitate tumor resection while preserving the labyrinth.

Factors That Affect Length of Hospital Stay After Vestibular Schwannoma Surgery.

OBJECTIVE: To identify perioperative factors that influence hospital length of stay (LOS) after resection of vestibular schwannoma (VS). STUDY DESIGN: Retrospective case review. SETTING: Tertiary skull base referral center. PATIENTS: Patients who underwent acoustic neuroma resection between January 1, 2007 and January 1, 2014. INTERVENTIONS: Approaches used for VS resection included translabyrinthine and retrosigmoid. MAIN OUTCOME MEASURES: LOS and several perioperative factors that may delay hospital discharge were examined. Factors included were patient demographics (age and sex), tumor characteristics (size), surgical factors (operative time, approach, revision surgery, date of surgery), and immediate postoperative factors (presence of vertigo or immediate postoperative complications). RESULTS: Two hundred eighty-eight patients underwent VS resection during the study period. Two hundred fifty-five patients had complete charts available for review. LOS ranged from 1 to 10 days with an average of 2.66 days and mode of 2 days. One hundred thirty-one patients were admitted for ≤2 days and 124 patients stayed longer. Of the perioperative factors examined with univariate analysis, female gender (p = 0.0266) and presence of postoperative vertigo (p < 0.0001) were statistically significant factors associated with LOS >2 days. On multivariate logistic regression analysis with odds ratios (OR), older patient age (OR = 1.028, p = 0.0177), female gender (OR = 1.810, p = 0.0314), longer operative time (OR = 1.424, p = 0.0007), and presence of postoperative vertigo (OR = 4.904, p < 0.0001) carried a statistically significant increased odds toward a LOS >2 days. CONCLUSIONS: VS surgery and postoperative care can be carried out efficiently with a minimal LOS. Identifying factors that may prolong LOS may help the operative team anticipate and address needs to optimize LOS.

Congenital aural atresia: review of short- and long-term surgical results.

OBJECTIVES/HYPOTHESIS: To review the short- (<1 yr) and long-term (>1 yr) surgical and hearing outcomes for congenital aural atresia and to analyze the stability of surgical results over time. STUDY DESIGN: Retrospective chart review of 45 patients (54 ears) who underwent surgery for congenital aural atresia during a 5-year period at a tertiary care institution. METHODS: Preoperative and postoperative speech reception thresholds, air-bone gaps (ABGs), and pure-tone averages were compared and further analyzed for outcome stability over time. The complication rate was reviewed and compared with results from similar studies. RESULTS: Approximately 50% of patients achieved a speech reception threshold of 30 dB or better both in the short and long term. The average improvement in ABG was 22 dB, resulting in a postoperative ABG of 30 dB or less in three of four patients. Short- and long-term outcomes were not significantly different. Patients with an intact ossicular chain did not seem to have a significant advantage in hearing when compared with patients with a prosthetic reconstruction prosthesis. We report a low incidence of meatal stenosis compared with other similar reviews and describe surgical modifications that may attribute to this outcome. CONCLUSION: Overall, the mean hearing outcome for this group collectively did not significantly degrade over time and compared favorably with other series. However, there was significant variability among individual patients. The safety of this procedure and the demonstrated hearing improvement makes it a reasonable option in patients with congenital aural atresia with favorable anatomy.

Long-term MRI surveillance after microsurgery for vestibular schwannoma.

OBJECTIVES: To determine the optimal postoperative magnetic resonance imaging (MRI) schedule and length of follow-up for patients undergoing microsurgical excision of vestibular schwannoma (VS). STUDY DESIGN: A retrospective review of patients who underwent microsurgical excision of VS at a single tertiary care center between January 1993 and March 2004. METHODS: Two hundred and twenty subjects were analyzed and characteristics gathered, including tumor size, surgical approach, completeness of resection, and length of follow-up to last MRI. All postoperative MRIs were reviewed. Radiologic progression is defined as a transition to a more advanced MRI grade from a less advanced MRI grade (eg, clean, linear, nodular) and was recorded for each of the subjects' serial MRIs. The MRI categorized findings were also binned into five time periods for summary analyses. Interval-censored survival analysis was performed to model time to recurrence across the population. RESULTS: Of the non-neurofibromatosis type 2 (NF2) cohort, the average tumor size at the time of resection was 1.98 ± 1.02 cm (range 0.4-5 cm); average length of follow-up was 9.0 ± 4.6 years (range 1-19); 102 subjects (47.2%) underwent a retrosigmoid resection; and 110 (50.9%) underwent a translabyrinthine resection. Eight of these subjects (4.1%) demonstrated radiologic progression; of those, four underwent additional treatment. Survival analysis showed early (1-2 years postoperative), middle (2-10 years postoperative), and late (> 10 years postoperative) radiologic progression events. CONCLUSION: The current recommended MRI surveillance schedule after microsurgery for VS includes MRIs at 1, 5, and 10 years postoperatively. Nonparametric survival analysis suggests that a majority of radiologic progression events occur in the first 10 years postoperatively. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2132-2138, 2017.

Surgical and Audiometric Outcomes for Repair of Congenital Aural Atresia and Hypoplasia.

IMPORTANCE: Surgical repair of congenital aural atresia and hypoplasia (CAAH) is technically challenging. Long-term surgical and audiologic outcomes of atresiaplasty are incompletely understood. OBJECTIVES: To review the surgical outcomes for CAAH and analyze the hearing results. DESIGN, SETTING, AND PARTICIPANTS: A retrospective medical record review of CAAH outcomes was performed during an 11-year period from January 1, 2004, through December 31, 2014. The data analysis was undertaken from December 1, 2014, through January 31, 2015. The mean clinic follow-up time was 3.9 years, and the mean audiologic follow-time was 2.8 years. The study included 98 patients aged 5 to 66 years (mean age, 16.6 years) with CAAH who underwent a total of 104 operations. INTERVENTIONS: Surgical repair of CAAH. MAIN OUTCOMES AND MEASURES: Preoperative and postoperative pure-tone averages (PTAs), speech reception thresholds (SRTs), air-bone gaps (ABGs), and interaural PTA and SRT differences were compared. Factors that affect hearing outcomes were analyzed. The complication rates were reviewed and compared with results from similar studies. RESULTS: In the 98 patients with CAAH, the mean improvement in ABGs and SRTs was 26.7 and 25.9 dB, respectively, resulting in a postoperative ABG of 30 dB or less in 4 of 5 cases. The mean postoperative PTAs and SRTs were 36.9 and 34.3 dB, respectively. Patients with a functional native ossicular chain (36 of 104 [34.6%]) had significantly superior audiometric outcomes when compared with patients in whom a reconstruction prosthesis was required during primary or revision operations. Audiometric results from hypoplasia surgery were not significantly different from those of atresia surgery; results in patients with craniofacial syndromes were similarly not significantly different from those in patients with sporadic CAAH. We report a low incidence of meatal stenosis. CONCLUSIONS AND RELEVANCE: The mean hearing outcomes for this group compared favorably with other series. The need for ossicular chain reconstruction was associated with poorer audiometric outcomes. The safety profile and the demonstrated hearing improvement of CAAH surgery suggest that it remains a favorable option for patients.

Approach design and closure techniques to minimize cerebrospinal fluid leak after cerebellopontine angle tumor surgery.

OBJECTIVE: The purpose of the study was to identify specific aspects of surgical approach design and closure technique aimed at reducing the incidence of cerebrospinal fluid leak after cerebellopontine angle tumor surgery. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: All patients undergoing cerebellopontine angle tumor surgery at the study institution from January 1996 through September 2004. MAIN OUTCOME MEASURE: The presence or absence of cerebrospinal fluid leak after various surgical approaches for a wide variety of cerebellopontine angle tumors. RESULTS: Three hundred forty three patients underwent surgery for cerebellopontine angle tumors at the study institution during the study period. Tumor types in descending order of frequency were as follows: acoustic neuroma, 244; cerebellopontine angle meningiomas, 33; petroclival meningiomas, 32; foramen magnum meningiomas, 10; epidermoid tumors, 9; facial nerve tumors, 6; hemangiopericytomas, 3; schwannomas of glossopharyngeal/spinal accessory nerves, 3; and unusual internal auditory canal tumors, 3. Surgical approaches used for tumor resection included translabyrinthine, retrosigmoid, combined transpetrosal, far lateral/transcondylar, middle cranial fossa, and extended middle cranial fossa. During the nearly 8-year study period, four postoperative cerebrospinal fluid leaks were encountered, resulting in a leak rate of 1.2%. Two of these patients required surgical repair of their leaks; the other two stopped spontaneously. The authors describe specific aspects of approach design and closure that appear to have a positive impact on postoperative cerebrospinal fluid leak rates. CONCLUSION: Attention to specific aspects of surgical approach design and wound closure results in a reduced incidence of cerebrospinal fluid leak after surgery for cerebellopontine angle tumors.

Facial nerve function after the extended translabyrinthine approach.

Objective To evaluate facial nerve function after excision of petroclival/anterior cerebellopontine angle (CPA) meningiomas by the extended translabyrinthine (EXTL) approach and compare these with outcomes after the transcochlear and transotic approaches. Design Retrospective chart review. Setting/Participants A search of archived surgical cases at a single institution between January 1, 1995, and January 1, 2012. Main Outcome Measures Facial function measured on the House-Brackmann (HB) scale. Results A total of 16 patients underwent the EXTL approach for primary excision of petroclival meningiomas. Average tumor size was 4.6 cm, and six patients had gross total resection. Average length of follow-up was 36.4 months. Two patients required reoperation for tumor regrowth. Preoperative facial function was HB I or II in all patients with available examinations. Immediate postoperative facial nerve function ranged from HB I to HB VI. In patients with an intact facial nerve at surgery, all but one had long-term facial function of HB I or II. A robust response on intraoperative facial nerve monitoring was prognostic of favorable long-term facial function. Facial function declined in some patients after postoperative radiation or revision surgery. Conclusions The EXTL approach allows excellent exposure of petroclival/anterior CPA lesions and should be favored to improve facial outcomes.

Auditory brainstem response versus magnetic resonance imaging for the evaluation of asymmetric sensorineural hearing loss.

OBJECTIVES/HYPOTHESIS: Auditory brainstem response (ABR) testing and magnetic resonance imaging (MRI) are compared for the evaluation of patients with asymmetric sensorineural hearing loss (SNHL). MRI with gadolinium administration is the current gold standard for identifying retrocochlear lesions causing asymmetric SNHL. The study seeks to determine the sensitivity and specificity of ABR in screening for possible retrocochlear pathology. Most important among SNHL etiologies are neoplastic lesions such as vestibular schwannomas, cerebellopontine angle (CPA) tumors, as well as multiple sclerosis, stroke, or other rare nonneoplastic causes. The study results will allow the author to recommend a screening algorithm for patients with asymmetric SNHL. STUDY DESIGN: The study is a multi-institutional, institutional review board approved, prospective, nonrandomized comparison of ABR and MRI for the evaluation of patients with asymmetric SNHL. METHODS: Three hundred twelve patients (between the ages of 18 and 87) with asymmetric SNHL completed the study. Asymmetric SNHL was defined as 15 dB or greater asymmetry in two or more frequencies or 15% or more asymmetry in speech discrimination scores (SDS). These patients prospectively underwent both ABR and MRI. The ABR and MRI were interpreted independently in a blinded fashion. In addition to the ABR and MRI results, a variety of clinical and demographic data were collected. RESULTS: Thirty-one (9.94%) patients of the study population of 312 were found on MRI to have lesions causing their SNHL. Of the 31 patients with causative lesions on MRI there were 24 vestibular schwannomas, 2 glomus jugulare tumors, 2 ectatic basilar arteries with brainstem compression, 1 petrous apex cholesterol granuloma, 1 case of possible demyelinating disease, and 1 parietal lobe mass. Twenty-two of the 31 patients had abnormal ABRs, whereas 9 patients (7 with small vestibular schwannomas) had normal ABRs. This gives an overall false-negative rate for ABR of 29%. The false-positive rate was found to be 76.84%. Sensitivity of ABR as a screening test was 71%, and specificity was 74%. CONCLUSIONS: Ten percent of patients with asymmetric SNHL (by this study's criteria) are likely to have causative lesions found on MRI. Although the recently reported annual incidence of vestibular schwannoma in the general population is 0.00124%, for patients with asymmetric SNHL in this study, the incidence was 7.7% (nearly 4 orders of magnitude higher). ABR has been demonstrated to have low sensitivity and specificity in the evaluation of these patients and cannot be relied on as a screening test for patients with asymmetric SNHL. Keeping the use of MRI conditional on the results of ABR will annually result in missed or delayed diagnosis of causative lesions in 29 patients per 1,000 screened. The author recommends abandoning ABR as a screening test for asymmetric SNHL and adoption of a focused MRI protocol as the screening test of choice (within certain guidelines).

Extended middle fossa approach to the petroclival junction and anterior cerebellopontine angle.

OBJECTIVES: This article seeks to demonstrate the use of the extended middle cranial fossa approach in the treatment of tumors arising in the anterior cerebellopontine angle and petroclival region. STUDY DESIGN: We conducted a retrospective chart review. SETTING: Tertiary referral center. PATIENTS: : Ten-year retrospective chart review of over 800 skull base surgical cases demonstrated 16 cases in which the senior author used the extended middle cranial fossa as the sole approach to access the posterior cranial fossa, petroclival junction, or the anterior cerebellopontine angle. There were five males and 11 females, 13 meningiomas, 2 trigeminal schwannomas, and 1 brainstem glioma. Presenting symptoms were dependent on extent of brainstem compression and involvement of surrounding cranial nerves. The symptoms are broken down as follows: hydrocephalus, one; balance disturbance, three; diplopia, five; trigeminal neuralgia, two; hemifacial numbness, one; seizures, one; expressive aphasia, one; and hearing loss, two. RESULTS: Of the 16 patients in this study, one patient needed postoperative care in a skilled nursing facility. Postoperative facial nerve weakness was not experienced in any patient. One patient developed a transient cerebrospinal fluid leak that resolved spontaneously. One patient developed a pseudomeningocele secondary to postoperative hydrocephalus. This was corrected with wound exploration and placement of a ventricular peritoneal shunt. Hearing was not maintained in one patient. Two patients developed new fourth nerve paresis and two patients developed new sixth nerve palsies. There were no postoperative infections and no deaths. CONCLUSIONS: The extended middle cranial fossa approach provides excellent access and exposure to tumors in the anterior cerebellopontine angle and petroclival junction. The approach allows more direct access to the area anterior to the internal auditory canal. The key to the approach is adequate bone removal of the petrous apex to provide exposure down to the inferior petrosal sinus and anteriorly to Meckel's cave and the petroclival junction. Extradural elevation of the temporal lobe with suitable brain relaxation minimizes postoperative complications.