Endoscopic-Assisted Presigmoid Approach to the Internal Auditory Canal. A Feasibility Study.

HYPOTHESIS: The retrolabyrinthine (presigmoid) approach has been utilized in various skull base surgeries but has not been fully utilized in the management of internal auditory canal (IAC) lesions, such as vestibular schwannoma (VS). Microsurgical retrolabyrinthine approach provides limited visualization of the IAC, while endoscopic-assisted techniques allow for further lateral exposure with labyrinthine preservation. BACKGROUND: Traditional approaches to the IAC have the disadvantage of hearing sacrifice or retraction of brain tissue. With the introduction of endoscopic techniques and enhanced visualization, access to this region of complex anatomy is possible. METHODS: Radiomorphometric and anatomical dissection was performed on two cadaveric temporal bones. High-resolution computed tomography was used to segment and delineate the volume of the IAC. Projected accessible IAC was compared to actual postdissection data with preservation of the posterior semicircular canal (PSCC) via the retrolabyrinthine corridor. RESULTS: While preserving the PSCC, the 0° and 30° endoscopes visualized 57.1% and 78.6% of the IAC for cadaver 1, and 64.0% and 76.0% of the IAC for cadaver 2, respectively. Sacrificing the PSCC, the 0° and 30° endoscopes provided visualization of 78.6% 85.7% of the IAC for cadaver 1, and 88.0% and 95.1% of the IAC for cadaver 2, respectively. CONCLUSIONS: Retrolabyrinthine approach to resection of VS is a potentially viable hearing-preserving alternative to traditional approaches. This approach provides access to the majority of the IAC, while angled endoscopes or sacrifice of the PSCC can provide additional access toward the fundus. Further studies are needed to determine the clinical feasibility of this approach.

Making a racket in America's fastest growing sport: Evaluation of noise exposure in pickleball.

OBJECTIVE: To measure noise exposure present on pickleball courts and assess the risk of noise-induced hearing loss (NIHL) per guidelines put forward by the National Institute of Occupational Safety and Health (NIOSH). METHODS: Observational study measuring noise levels at multiple recreational pickleball courts in the Richmond, VA area, documenting LAeq, LASmax, and LCpeak at courtside and waiting areas of pickleball courts. Measurements were completed using the NIOSH SLM application on an iPhone 13 with iMM-6 Calibrated Measurement Microphone (equivalent to IEC 61672-1 Class II) that was calibrated using ND-9 Sound Level Calibrator (IEC942 Class I). RESULTS: Average sound levels recorded at waiting areas adjacent to the courts, measured in LAeq, LASmax, and LCpeak, were 69.1 dBA, 92.0 dBA, and 112.1 dBC, respectively, while courtside measurements were 69.7 dBA, 92.2 dBA, and 115.6 dBC, respectively. These measurements were within NIOSH and OSHA recommendations. CONCLUSION: The data demonstrates that randomly sampled pickleball courts have noise levels that do not increase risk for NIHL for participants or bystanders alike based on NIOSH guidelines. However, prolonged noise exposure and ambient noise pollution may have other health implications and warrant further investigations. LEVEL OF EVIDENCE: Level 2.

Increased Incidence of Vestibular Disorders in Patients With SARS-CoV-2.

Objective: Determine the incidence of vestibular disorders in patients with SARS-CoV-2 compared to the control population. Study Design: Retrospective. Setting: Clinical data in the National COVID Cohort Collaborative database (N3C). Methods: Deidentified patient data from the National COVID Cohort Collaborative database (N3C) were queried based on variant peak prevalence (untyped, alpha, delta, omicron 21K, and omicron 23A) from covariants.org to retrospectively analyze the incidence of vestibular disorders in patients with SARS-CoV-2 compared to control population, consisting of patients without documented evidence of COVID infection during the same period. Results: Patients testing positive for COVID-19 were significantly more likely to have a vestibular disorder compared to the control population. Compared to control patients, the odds ratio of vestibular disorders was significantly elevated in patients with untyped (odds ratio [OR], 2.39; confidence intervals [CI], 2.29-2.50; P < 0.001), alpha (OR, 3.63; CI, 3.48-3.78; P < 0.001), delta (OR, 3.03; CI, 2.94-3.12; P < 0.001), omicron 21K variant (OR, 2.97; CI, 2.90-3.04; P < 0.001), and omicron 23A variant (OR, 8.80; CI, 8.35-9.27; P < 0.001). Conclusions: The incidence of vestibular disorders differed between COVID-19 variants and was significantly elevated in COVID-19-positive patients compared to the control population. These findings have implications for patient counseling and further research is needed to discern the long-term effects of these findings.

Outcomes of Near-Total and Subtotal Resection of Sporadic Vestibular Schwannoma: A Systematic Review and Meta-Analysis.

OBJECTIVE: To evaluate tumor control and facial nerve outcomes after gross-total (GTR), near-total (NTR), and subtotal resection (STR) of sporadic vestibular schwannomas (VS). DATA SOURCES: PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched in August 2021 through inception following PRISMA guidelines. REVIEW METHODS: English language articles reporting tumor control and facial nerve outcomes of adults (≥18 years) with NTR and STR of VS were evaluated. Study characteristics, demographics data, tumor characteristics, type of surgical intervention, and outcome measures on tumor control and facial nerve function were collected. Pooled relative risk (RR) estimates for tumor recurrence and facial nerve outcomes were calculated and stratified by extent of resection. RESULTS: From an initial search of 2504 articles, 48 studies were included in the analysis. When comparing 1108 patients who underwent NTR to 3349 patients with GTR, the pooled RR of recurrence in the NTR cohort was 2.94 (95% confidence interval [CI] 1.65-5.24, P = .0002). When comparing 1016 patients who underwent STR to 6171 patients with GTR, the pooled RR of recurrence in the STR cohort was 11.50 (95% CI 6.64-19.92, P < .0001). Estimates for risk of tumor regrowth for less-than-complete resection are presented. There was no elevated risk of adverse facial nerve outcome (defined as House-Brackmann grade III and above) in each category of extent of resection compared to GTR. CONCLUSION: Extent of resection predicts risk of tumor recurrence/regrowth following microsurgical resection. Favorable facial nerve outcome should be weighed against the increased risk of regrowth and the potential need for further treatment.

Temporal Bone Resection for Squamous Cell Carcinoma of the Lateral Skull Base: Systematic Review and Meta-analysis.

OBJECTIVE: Temporal bone squamous cell carcinoma (TBSCC) is rare and often confers a poor prognosis. The aim of this study was to synthesize survival and recurrence outcomes data reported in the literature for patients who underwent temporal bone resection (TBR) for curative management of TBSCC. We considered TBSCC listed as originating from multiple subsites, including the external ear, parotid, and external auditory canal (EAC), or nonspecifically from the temporal bone. DATA SOURCES: PubMed, Cochrane Library, Embase, and manual search of bibliographies. REVIEW METHOD: A systematic literature review conducted in December 2020 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Survival data were collected from 51 retrospective studies, resulting in a pooled cohort of 501 patients with TBSCC. Compared to patients undergoing lateral TBR (LTBR), patients undergoing subtotal (SBTR) or total (TTBR) TBR exhibited significantly higher rates of stage IV disease (P < .001), positive surgical margins (P < .001), facial nerve involvement (P < .001), and recurrent disease (P < .001). A meta-analysis of 15 studies revealed a statistically significant 97% increase in mortality in patients who underwent STBR or TTBR. On multivariate analysis, recurrent disease was independently associated with worse overall survival (P < .001). On univariate analysis, facial nerve involvement was also associated with decreased overall survival (P < .001). CONCLUSION: Recurrent disease was associated with risk of death in patients undergoing TBR. Larger prospective multi-institutional studies are needed to ascertain prognostic factors for a wider array of postoperative outcomes, including histology-specific survival and recurrence outcomes.

Doxycycline-Induced Intracranial Hypertension Presenting as Unilateral Pulsatile Tinnitus.

Background: Pulsatile tinnitus (PT) is increasingly recognized as a cardinal symptom of idiopathic intracranial hypertension (IIH). However, clinicians should remain aware of other causes of nonidiopathic or secondary intracranial hypertension manifesting as PT. We present 2 patients with isolated PT (without accompanying headache, blurred vision, and papilledema) thought to be secondary to tetracycline-induced intracranial hypertension. To our knowledge, these are the first cases of PT as the presenting symptom of this condition. Cases: A 41-year-old female (body mass index [BMI] 29 kg/m2) with ocular rosacea was initially treated with minocycline. Shortly after transitioning to oral doxycycline and erythromycin eye ointment, she noted left-sided PT. Her PT resolved after discontinuing doxycycline. In a second case, a 39-year-old female (BMI 19 kg/m2) with acne presented with a three-year history of left-sided PT while on long-term oral doxycycline for many years. She denied visual or auditory changes and atypical headaches. MRI findings were concerning for intracranial hypertension. Three months later, the patient was seen by neuro-ophthalmology, with findings suggesting prior papilledema. The patient reported PT improvement after discontinuing doxycycline. Conclusions: This case series highlights 2 cases of isolated PT as the sole symptom of intracranial hypertension that resolved with tetracycline cessation. The presentation and unexpected improvement following tetracycline discontinuation are atypical compared with previous reports of tetracycline-induced intracranial hypertension. Clinicians should maintain a high index of suspicion for all types of intracranial hypertension (idiopathic and secondary), even in patients with a lower BMI. Current and prior medications should be reviewed when considering the etiology of intracranial hypertension.

Vestibular Migraine Confounds Management of Superior Canal Dehiscence Syndrome.

OBJECTIVE: To investigate the prevalence of vestibular migraine (VM) in a cohort of patients with radiologic confirmation of superior canal dehiscence (SCD) and to compare management of superior canal dehiscence syndrome (SCDS) in patients with and without comorbid VM. STUDY DESIGN: Retrospective review of a SCD database. SETTING: University-based tertiary medical center. PATIENTS: Ninety-one patients identified with SCD from 2009 to 2017. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Coincidence of VM and SCD, and resolution of symptoms. RESULTS: Ninety-one patients with SCD met the inclusion and exclusion criteria. VM was diagnosed in 36 (39.6%) patients. Of those receiving medical therapy for VM alone, five (45.5%) reported symptom resolution, five (45.5%) reported partial improvement, one (9.1%) had no change, and none worsened. Fifteen patients (41.7%) were treated with both surgery (for SCD) and medical therapy (for VM). Seven (46.7%) reported symptom resolution, seven (46.7%) reported partial improvement, and one (6.7%) worsened. There was no statistically significant difference in symptom resolution between SCD + VM patients who were treated medically compared with those treated with medical therapy and surgery (p = 0.951). There was no significant difference in symptom resolution after surgery between SCD + VM and SCD-only cohorts (p = 0.286). CONCLUSIONS: This is the first study describing the incidence of VM in a cohort of patients with SCDS. The symptoms of VM confound those of SCDS and unrecognized or undertreated VM may contribute to surgical failure in SCDS. Therefore, we recommend a high index of suspicion for VM in patients with SCDS and a trial of medical therapy in the setting of suspected VM.

Reducing ICU Length of Stay: The Impact of a Multidisciplinary Perioperative Pathway in Vestibular Schwannoma.

Objective This study was aimed to evaluate the impact of a multidisciplinary perioperative pathway on length of stay (LOS) and postoperative outcomes after vestibular schwannoma surgery. Setting This study was conducted in a tertiary skull base center. Main Outcome Measures The impact of the pathway on intensive care unit (ICU) LOS was evaluated as the primary outcome measure of the study. Overall resource LOS, postoperative complications, and readmission rates were also evaluated as secondary outcome measures. Methods Present study is a retrospective review. Results A universally adopted perioperative pathway was developed to include standardization of preoperative education and expectations, intraoperative anesthetic delivery, postoperative nursing education, postoperative rehabilitation, and utilization of stepdown and surgical floor units after ICU stay. Outcomes were measured for 95 consecutive adult patients who underwent surgical resection for vestibular schwannoma (40 cases before implementation of the perioperative pathway and 55 cases after implementation). There were no significant differences in the two groups with regard to tumor size, operative time, or medical comorbidities. The mean ICU LOS decreased from 2.1 in the preimplementation group to 1.6 days in the postimplementation group ( p = 0.02). There were no significant differences in overall resource LOS postoperative complications or readmission rates between groups. Conclusion Multidisciplinary, perioperative neurotologic pathways can be effective in lowering ICU LOS in patients undergoing vestibular schwannoma surgery without compromising quality of care. Further research is needed to continue to sustain and continuously improve these and other measures, while continuing to provide high-quality care to this patient population.

Comparative Analysis of Recidivism After Endoscopic and Microscopic-Based Cholesteatoma Resection.

OBJECTIVES: 1) To analyze outcomes of cholesteatoma resection utilizing postauricular microscopic and endoscopic ear surgery (EES) approaches.2) To analyze predictors of residual and recurrent cholesteatoma. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: Three hundred seventy-five adult and pediatric patients with cholesteatoma (2012-2017). INTERVENTIONS: Patients underwent surgical resection of cholesteatoma with EES (n = 122) and microscopic (n = 253) approach. MAIN OUTCOME MEASURES: Residual cholesteatoma, recurrent cholesteatoma, second-look procedures. RESULTS: The endoscopic cohort included significantly more pediatric cases (p = 0.0008). There was no difference in laterality, gender distribution, congenital or acquired cholesteatoma, and revision cases between the cohorts. Out of 122 EES cases, 16 (13%) developed residual disease and 9 (7%) developed recurrent disease. Of 253 microscopic cases 16 (6%) developed residual disease while 11 (4%) developed recurrent disease. Second look procedures were more commonly used in EES cohort (50 vs 18%). Single predictor analysis revealed 12 predictors for residual disease and 5 for recurrent disease. Multivariable model identified pediatric case distribution and higher disease stage to be significant predictors for both residual (p = 0.04, 0.007) and recurrent disease (p = 0.02, 0.01). EES approach was associated with a weak significance for residual disease (p = 0.049) but not recurrent disease (p = 0.34). CONCLUSIONS: EES approach for cholesteatoma resection seems to perform similarly to microscopic approach with no difference in rates of recurrent disease. However, it is associated with a higher rate of residual disease; this may be a reflection of a greater rate of second look procedures done in this group.

Predictors of Recurrence After Sub-total or Near-total Resection of Vestibular Schwannoma: Importance of Tumor Volume and Ventral Extension.

OBJECTIVE: To evaluate the predictors of remnant tumor regrowth and need for salvage therapy after less than gross total resection (GTR) of vestibular schwannoma (VS). STUDY DESIGN: Retrospective chart review. SETTING: Tertiary neurotologic referral center. PATIENTS: Patients who underwent VS resection between 2008 and 2019 either with GTR, near total resection (NTR), and subtotal resection (STR). INTERVENTIONS: Microsurgical resection, salvage radiosurgery. MAIN OUTCOME MEASURES: Regrowth free interval, salvage free interval, tumor doubling rate. RESULTS: Three hundred eighty five cases (GTR = 236, NTR = 77, and STR = 71) from 2008 to 2019 were included. STR cohort had much larger and complex tumors with significant differences in tumor volume, ventral extension and brainstem compression (p  < 0.001). On single predictor analysis, tumor volume, ventral extension, brainstem compression as well as STR strategy was associated with significant increased risk of regrowth and need for salvage therapy. Multivariate analysis revealed STR strategy as significant predictor of regrowth (hazard ratio 3.79, p  < 0.0005). Absolute remnant volume and extent of resection (EOR) did not predict regrowth. A small proportion of cases (NTR = 4%, STR = 15%) eventually needed salvage radiosurgery with excellent ultimate local tumor control with no known recurrence to date. CONCLUSIONS: Conservative surgical strategy employing NTR or STR can be employed safely in large and complex VS. While there is increased risk of regrowth in the STR cohort, excellent local control can be achieved with appropriate use of salvage radiosurgery. No disceret radiologic or operative predictors of regrowth were identified.

Cochlear Implantation Outcomes in Observed Vestibular Schwannoma: A Preliminary Report.

OBJECTIVE: Over the last decade there has been a trend toward observation for small nongrowing vestibular schwannoma (VS). Even without tumor growth, patients commonly experience ipsilateral hearing decline, and hearing rehabilitation remains challenging. This study analyzes hearing and speech performance outcomes after cochlear implantation (CI) in observed VS. STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. METHODS: Chart review was used to include patients with observed VS who had undergone ipsilateral CI, pre- and postimplantation audiometry, and speech performance. Tumor size pre- and postimplantation was measured with volumetric analysis. RESULTS: Seven patients with ipsilateral VS and CI were identified. Preimplantation tumor volume was 0.11 to 1.02 cm3. Five subjects were implanted with a straight electrode and two with a perimodiolar electrode. The average preimplant pure tone average was 91.3 dB (range, 80-117 dB) and 61.2 dB (range, 12-118 dB) for the implanted and nonimplanted ears, respectively. In all subjects with at least 1 year of listening experience (n = 6), consonant-nucleus-consonant word scores improved at 6 months and 1 year in the CI-alone and bimodal listening conditions. AzBio scores in quiet also improved at 6 months and 1 year. Of subjects with serial pre- and postoperative magnetic resonance imaging, volumetric analysis demonstrated no tumor growth. CONCLUSION: Our results demonstrate that CI is a successful option for subjects with small nongrowing VS. All subjects had improved performance postimplantation. VS may continue to be observed with serial magnetic resonance imaging given increasing conditionality among CI manufacturers and ability to assess cerebellopontine angle extension despite implant artifact.

Predictive Modeling and Risk Stratification of Patients With Enlarged Vestibular Aqueduct.

OBJECTIVES/HYPOTHESIS: To investigate patient-specific characteristics that independently predict for progressive hearing loss in patients with enlarged vestibular aqueduct (EVA). Utilize multivariable predictive models to identify subgroups of patients with significantly different progression risks. STUDY DESIGN: Retrospective analysis of patients evaluated at an academic tertiary care center. Cohort included 74 ears of patients with a diagnosis of EVA as defined by the Cincinnati criteria. METHODS: Hearing trajectories were characterized, and a Kaplan-Meier estimator was utilized to determine progressive phenotype probabilities across the first 10 years after diagnosis. Cox proportional hazard regression was used to identify patient characteristics that independently altered this probability. Stratified risk groups were delineated from generated nomogram scores. RESULTS: Male gender was associated with a 4.53 hazard ratio for progressive hearing loss (95% confidence interval [CI], 2.53 to 12.59). Each millimeter increase in operculum size was independently associated with an 80.40% increase in expected hazard (95% CI, 40.18 to 120.62). Each dB increase in air pure tone average at time of diagnosis decreased expected hazard by 1.59% (95% CI, -3.02 to -0.17). The presence of incomplete partition type II was associated with a 2.44 hazard ratio (95% CI, 1.04 to 5.72). Risk groups stratified by median nomogram score evidenced the discriminative ability of our model with the progression probability in the high-risk group being six times higher at 1 year, nearly five times greater at 3 years, and three times greater at 9 years. CONCLUSIONS: EVA patient characteristics can be used to predict hearing loss probability with a high degree of accuracy (C-index of 0.79). This can help clinicians make more proactive management decisions by identifying patients at high risk for hearing loss. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:1439-1445, 2022.

Intraoperative Correction of Cochlear Implant Electrode Translocation.

INTRODUCTION: Translocation of precurved cochlear implant (CI) electrodes reduces hearing outcomes, but it is not known whether it is possible to correct scalar translocation such that all electrodes reside fully in the scala tympani (ST). METHODS: Six cadaveric temporal bones were scanned with CT and segmented to delineate intracochlear anatomy. Mastoidectomy with facial recess was performed. Precurved CI electrodes (CI532; Cochlear Limited) were implanted until scalar translocation was confirmed with postoperative CT. Then, electrodes were removed and replaced. CT scan was repeated to assess for translocation correction. Scalar position of electrode contacts, angular insertion depth (AID) of the electrode array, and M- (average distance between each electrode contact and the modiolus) were measured. An in vivo case is reported in which intraoperative translocation detection led to removal and replacement of the electrode. RESULTS: Five of 6 cadaveric translocations (83%) were corrected with 1 attempt, resulting in full ST insertions. AID averaged 285 ± 77° for translocated electrodes compared to 344 ± 28° for nontranslocated electrodes (p = 0.109). M- averaged 0.75 ± 0.18 mm for translocated electrodes and 0.45 ± 0.11 mm for nontranslocated electrodes (p = 0.016). Reduction in M- with translocation correction averaged 38%. In the in vivo case, translocation was successfully corrected in a single attempt. CONCLUSION: Scalar translocation of precurved CI electrodes can be corrected by removal and reinsertion. This significantly improves the perimodiolar positioning of these electrodes. There was a high rate of success (83%) in this cadaveric model as well as a successful in vivo attempt.

Endoscope-Assisted Superior Semicircular Canal Dehiscence Repair: Single Institution Outcomes.

OBJECTIVE: To compare outcomes of endoscope-assisted middle cranial fossa MCF) repair of superior semicircular canal dehiscence (SSCD) compared to microscopic MCF repair. STUDY DESIGN: Retrospective cohort. SETTING: Tertiary medical center neurotology practice. METHODS: Retrospective chart review and cohort study of patients who underwent surgical repair of SSCD via MCF approach from 2010 to 2019 at our institution. Patients were categorized according to use of endoscope intraoperatively. Pre- and post-operative symptom number was calculated from 8 patient-reported symptoms. Pre- and post-operative changes in symptom number were assessed using paired t-tests. Single-predictor binary logistic regression was used to compare final reported symptoms between cohorts. Linear regression was performed to assess air-bone gap (ABG) changes postoperatively between cohorts. RESULTS: Forty-six patients received surgical management for SSCD. Of these, 27 (59%) were male and 19 (41%) were female. Bilateral SSCD was present in 14 cases (29%), of which 3 underwent surgical management bilaterally, for a total of 49 surgical ears. Surgery was performed on the right ear in 19 cases (39%) and on the left in 30 cases (61%). Forty ears (82%) underwent microscopic repair while 9 (18%) underwent endoscope-assisted repair. Microscopic and endoscope-assisted MCF repair both demonstrated significantly improved symptom number postoperatively (P < .001 for each). There was no significant difference in change in ABG between the 2 cohorts. On average, patient-reported symptoms and audiometrically-tested hearing improved postoperatively in both groups. CONCLUSION: While endoscopic-assisted MCF repair has the potential to provide better visualization of medial and downslope defects, repair via this technique yields similar results and is equivalent to MCF repair utilizing the microscope alone.

Comparison of Small Intestinal Submucosal Graft and Autologous Tissue in Prevention of CSF leak after Posterior Fossa Craniotomy.

Objective To compare the use of porcine small intestinal submucosal grafts (SISG) and standard autologous material (fascia) in prevention of cerebrospinal fluid (CSF) leak and pseudomeningocele formation after translabyrinthine resection. Setting Set at the tertiary skull base center. Methods This is a retrospective chart review. After Institutional Review Board approval, we performed a retrospective cohort study evaluating CSF leak in patients who underwent resection of lateral skull base defects with multilayered reconstruction using either fascia autograft or porcine SISGs. Demographics were summarized with descriptive statistics. Logistic regression was used to compare autograft and xenograft cohorts in terms of CSF complications. Results Seventy-seven patients underwent lateral skull base resection, followed by reconstruction of the posterior cranial fossa. Of these patients, 21 (27.3%) underwent multilayer repair using SISG xenograft. There were no significant differences in leak-associated complications between autograft and xenograft cohorts. Ventriculoperitoneal shunt was necessary in one (1.8%) autograft and one (4.8) xenograft cases ( p = 0.49). Operative repair to revise surgical defect was necessary in three (5.4%) autograft cases and none in xenograft cases. Conclusion The use of SISG as a component of complex skull base reconstruction after translabyrinthine tumor resection may help reduce CSF leak rates and need for further intervention.

Outcomes of Transzygomatic Middle Cranial Fossa Approach for Skull Base Tumors-A Single Institutional Experience.

Objective This study aimed to evaluate surgical outcomes after transzygomatic middle cranial fossa (MCF) (TZ-MCF) approach for tumor control in patients with large skull base lesions involving the MCF and adjacent sites. Setting This study was done at the tertiary skull base center. Design This is a retrospective case series. Main Outcome Measures The main outcome measures were tumor control (recurrence), new-onset cranial neuropathies, facial nerve and audiometric outcomes, cerebrospinal fluid (CSF) leak, and wound complications. Results Sixteen patients were identified with a median age of 45 years (range: 20-72). The mean maximum tumor dimension was 5.49 cm (standard deviation [SD]: 1.2, range: 3.1-7.3) and the mean tumor volume was 28.5 cm 3 (SD: 18.8, range: 2.9-63.8). Ten (62.5%) tumors were left sided. The most common pathology encountered was meningioma ( n = 7) followed by chondrosarcoma ( n = 4). Mean follow-up was 36.3 (SD: 26.9) months. Gross total resection or near total resection was achieved in nine (56.2%) and planned subtotal resection was used in seven (43.7%). Postoperative additional new cranial nerve (CN) deficits included CN V ( n = 1), CN III ( n = 2), CN VI ( n = 1), and CN X ( n = 1). Major neurological morbidity (hemiplegia) was encountered in two patients with resolution. There were no cases of CSF leak, meningitis, hemorrhage, seizures, aphasia, or death. There was no recurrence or regrowth of residual tumor. Facial nerve function was preserved in all but one patient (House-Brackmann grade 2). Conclusion Various skull base tumors involving MCF with extension to adjacent sites can be successfully resected using the TZ-MCF approach in a multidisciplinary fashion. This approach yields optimal exposure and permits excellent tumor control with acceptable CN and neurological morbidity.

The Influence of Extent of Resection and Tumor Morphology on Facial Nerve Outcomes Following Vestibular Schwannoma Surgery.

OBJECTIVE: To determine the influence extent of resection and tumor characteristics on facial nerve (FN) outcomes following microsurgical resection of vestibular schwannoma (VS). STUDY DESIGN: Retrospective chart review. SETTING: Tertiary referral center. PATIENTS: Three hundred eighty-five patients who underwent VS microsurgical resection. INTERVENTIONS: Microsurgical VS resection. MAIN OUTCOME MEASURES: House-Brackmann (HB) scores postoperatively. Good FN function was defined as HB grade I and II and poor FN function was defined as HB grade III and VI. Gross total resection (GTR) versus subtotal resection (STR). Propensity-score matching was used in subset analysis to balance tumor volume between the surgical cohorts, followed by multivariable analysis. RESULTS: Seventy-one patients (18%) underwent STR and 314 patients (82%) underwent GTR. Two hundred fourteen patients (63%) had good FN function at 2 to 3 weeks postoperatively, and 80% had good FN function at 1 year. In single predictor analysis, STR did not influence FN function at 2 to 3 weeks (p = 0.65). In propensity-score matched subset analysis (N = 178), patients with STR were less likely to have poor FN function at 2 to 3 weeks (p = 0.02) independent of tumor volume (p = 0.004), but there was no correlation between STR and FN function at 1 year (p = 0.09). Ventral extension of tumor relative to the internal auditory canal plane was associated with poor FN outcomes at 2 to 3 weeks (p = 0.0001) and 1-year postop (p = 0.002). CONCLUSIONS: When accounting for tumor volume, STR is protective in immediate postoperative FN function compared to GTR. Ventral extension of the tumor is a clinical predictor of long-term FN outcomes.

Diameter-Based Volumetric Models May Inadequately Calculate Jugular Paraganglioma Volume Following Sub-Total Resection.

BACKGROUND: As gross total resection of jugular paragangliomas (JPs) may result in cranial nerve deficits, JPs are increasingly managed with subtotal resection (STR) with postoperative radiological monitoring. However, the validity of commonly used diameter-based models that calculate postoperative volume to determine residual tumor growth is dubious. The purpose of this study was to assess the accuracy of these models compared to manual volumetric slice-by-slice segmentation. METHODS: A senior neuroradiologist measured volumes via slice-by-slice segmentation of JPs pre- and postoperatively from patients who underwent STR from 2007 to 2019. Volumes from three linear-based models were calculated. Models with absolute percent error (APE) > 20% were considered unsatisfactory based on a common volumetric definition for residual growth. Bland-Altman plots were used to evaluate reproducibility, and Wilcoxon matched-pairs signed rank test evaluated model bias. RESULTS: Twenty-one patients were included. Median postoperative APE exceeded the established 20% threshold for each of the volumetric models as cuboidal, ellipsoidal, and spherical model APE were 63%, 28%, and 27%, respectively. The postoperative cuboidal model had significant systematic bias overestimating volume (p = 0.002) whereas the postoperative ellipsoidal and spherical models lacked systematic bias (p = 0.11 and p = 0.82). CONCLUSION: Cuboidal, ellipsoidal, and spherical models do not provide accurate assessments of postoperative JP tumor volume and may result in salvage therapies that are unnecessary or inappropriately withheld due to inaccurate assessment of residual tumor growth. While more time-consuming, slice-by-slice segmentation by an experienced neuroradiologist provides a substantially more accurate and precise measurement of tumor volume that may optimize clinical management.