Microsurgical Resection Of Vestibular Schwannoma Research Articles

Long-term quality of life outcomes in patients undergoing microsurgical resection of vestibular schwannoma

BackgroundWhile previous studies have assessed patient reported quality of life (QOL) of various vestibular schwannoma (VS) treatment modalities, few studies have assessed QOL as related to the amount of residual tumor and need for retreatment in a large series of patients. Objective: To assess patient reported QOL outcomes following VS resection with a focus on extent of resection and retreatment. MethodsA retrospective chart review was performed using single-center institutional data of adult patients who underwent VS resection by the senior authors between 1989-2018 at Loyola University Medical Center. The Penn Acoustic Neuroma Quality of Life (PANQOL) survey was sent to all patients via postal mail. ResultsFifty-five percent of 367 total patients were female with a mean age of 61.6 years (SD 12.63). The mean period between surgery and PANQOL response was 11.4 years (IQR: 4.74-7.37). The median tumor size was 2 cm (IQR: 1.5-2.8). The mean total PANQOL score was 70 (SD 19). Patients who required retreatment reported lower overall scores (μdiff = -10.11, 95% CI: -19.48 to -0.74; p = 0.03) and face domain scores (μdiff = -20.34, 95% CI: -29.78 to -10.91; p < .001). There was no association between extent of resection and PANQOL scores in any domain. ConclusionIn an analysis of 367 patients who underwent microsurgical resection of VS, extent of resection did not affect PANQOL scores in contrast to previous reports in the literature, while the need for retreatment and facial function had a significant impact on patient-reported outcomes.

Intraoperative ultrasonography in microsurgical resection of vestibular schwannomas via retrosigmoid approach: surgical technique and proof-of-concept illustrative case series.

Intraoperative ultrasonography (ioUS) is an established tool for the real-time intraoperative orientation and resection control in intra-axial oncological neurosurgery. Conversely, reports about its implementation in the resection of vestibular schwannomas (VS) are scarce. The aim of this study is to describe the role of ioUS in microsurgical resection of VS. ioUS (Craniotomy Transducer N13C5, BK5000, B Freq 8MHz, BK Medical, Burlington, MA, USA) is integrated into the surgical workflow according to a 4-step protocol (transdural preresection, intradural debulking control, intradural resection control, transdural postclosure). Illustrative cases of patients undergoing VS resection through a retrosigmoid approach with the use of ioUS are showed to illustrate advantages and pitfalls of the technique. ioUS allows clear transdural identification of the VS and its relationships with surgically relevant structures of the posterior fossa and of the cerebellopontine cistern prior to dural opening. Intradural ioUS reliably estimates the extent of tumor debulking, thereby helping in the choice of the right moment to start peripheral preparation and in the optimization of the extent of resection in those cases where subtotal resection is the ultimate goal of surgery. Transdural postclosure ioUS accurately depicts surgical situs. ioUS is a cost-effective, safe, and easy-to-use intraoperative adjunctive tool that can provide a significant assistance during VS surgery. It can potentially improve patient safety and reduce complication rates. Its efficacy on clinical outcomes, operative time, and complication rate should be validated in further studies.

The Effect of Immediate Microsurgical Resection of Vestibular Schwannoma on Hearing Preservation.

Evaluate for differences in postoperative hearing in patients who undergo immediate versus delayed hearing preservation microsurgical resection of vestibular schwannomas (VS). Retrospective single-institution cohort study spanning November 2017 to November 2021. Single-institution tertiary care hospital. Sporadic VS in patients with American Academy of Otolaryngology-Head and Neck Surgery hearing classification A or B, with tumor size less than or equal to 2 cm and undergoing hearing preservation microsurgical resection. Delayed surgical intervention defined by time from first diagnostic MRI to date of surgery being greater than 3 months. Preoperative and postoperative audiometric performance. In total, 193 patients met inclusion criteria. Within the cohort, 70 (36%) proceeded with surgery within 3 months of diagnostic MRI with a mean observation time of 62 days, whereas 123 (63%) underwent surgery after 3 months with a mean observation time of 301 days. There was no difference in preoperative hearing between the two groups with word recognition score 99% in early intervention group and 100% in delayed intervention group (p = 0.6). However, 64% of those who proceeded with immediate surgery had successful hearing preservation, compared to a 42% of those who had delayed intervention (p < 0.01). In a multivariable logistic regression accounting for preoperative word recognition score, tumor size, and age at diagnosis, the odds of hearing preservation were lower in those who delayed surgery compared to immediate surgery (odds ratio, 0.31; 95% confidence interval, 0.15-0.61). Patients who underwent microsurgical resection within 3 months of diagnosis demonstrated a hearing preservation advantage compared to those who did not. Findings of this study highlight the counseling challenges associated with the timing of surgical treatment of VS in patients presenting with good preoperative hearing and small tumors.

Salvage radiosurgery following subtotal resection of vestibular schwannomas: does timing influence tumor control?

The goal of microsurgical resection of vestibular schwannoma (VS) is gross-total resection (GTR) to provide oncological cure. However, a popular strategy is to halt the resection if the surgical team feels the risk of cranial nerve injury is imminent, achieving a maximally safe subtotal resection (STR) instead. The tumor remnant can then be treated with stereotactic radiosurgery (SRS) once the patient has recovered from the immediate postoperative period, or it can be followed with serial imaging and treated with SRS in a delayed fashion if residual tumor growth is seen. In this study, the authors evaluated the efficacy of this multimodality approach, particularly the influence of timing and dose of SRS on radiological tumor control, need for salvage treatment, and cranial nerve function. VS patients treated with initial microsurgery and subsequent radiosurgery were retrospectively included from two tertiary treatment centers and dichotomized depending on whether SRS was given upfront (defined as before 12 months) or later. Radiological tumor control was defined as less than 20% tumor volume expansion and oncological tumor control as an absence of salvage treatment. Facial and cochlear nerve functions were assessed after surgery, at the time of SRS, and at last follow-up. Finally, a systematic literature review was conducted according to PRISMA guidelines. A total of 110 VS patients underwent SRS following microsurgical resection, with a mean preradiosurgical tumor volume of 2.2 cm3 (SD 2.5 cm3) and mean post-SRS follow-up time of 5.8 years (SD 4.1 years). The overall radiological tumor control and oncological tumor control were 77.3% and 90.9%, respectively. Thirty-five patients (31.8%) received upfront SRS, while 75 patients (68.2%) were observed for a minimum of 12 months prior to SRS. The timing of SRS did not influence the radiological tumor control (p = 0.869), the oncological tumor control (p = 0.560), or facial nerve (p = 0.413) or cochlear nerve (p = 0.954) function. An escalated marginal dose (> 12 Gy) was associated with greater tumor shrinkage (p = 0.020) and superior radiological tumor control (p = 0.020), but it did not influence the risk of salvage treatment (p = 0.904) or facial (p = 0.351) or cochlear (p = 0.601) nerve deterioration. Delayed SRS after close observation of residuals following STR is a safe alternative to upfront SRS regarding tumor control and cranial nerve preservation in selected patients.

Three-Dimensional Exoscopic Versus Microscopic Resection of Vestibular Schwannomas: A Comparative Series.

Microsurgical resection of vestibular schwannoma (VS) is highly challenging, especially because surgical treatment nowadays is mainly reserved for larger (Koos grade 3 and 4) tumors. To assess the performance of three-dimensional exoscope use in VS resection in comparison with the operative microscope. Duration of surgery and clinical and radiological results were collected for 13 consecutive exoscopic schwannoma surgeries. Results were compared with 26 preceding microsurgical resections after acknowledging similar surgical complexity between groups by assessment of tumor size (maximum diameter and Koos grade), the presence of meatal extension or cystic components, and preoperative hearing and facial nerve function. Total duration of surgery was comparable between microscopically and exoscopically operated patients (264 minutes ± 92 vs 231 minutes ± 84, respectively; P = .276). However, operative time gradually decreased in consecutive exoscopic cases and in a multiple regression model predicting duration of surgery, and exoscope use was associated with a reduction of 58.5 minutes (95% CI -106.3 to -10.6; P = .018). Tumor size was identified as the main determinant of duration of surgery (regression coefficient = 5.50, 95% CI 3.20-7.80) along meatal extension and the presence of cystic components. No differences in postoperative hearing preservation and facial nerve function were noted between the exoscope and the microscope. Resection of VS using a foot switch-operated three-dimensional exoscope is safe and leads to comparable clinical and radiological results as resection with the operative microscope.

Does preoperative gamma knife treatment affect the result of microresection of vestibular schwannoma?

We aimed to explore the influence of preoperative gamma knife treatment on the clinical effect of microsurgical resection of vestibular schwannoma. The data of patients who underwent vestibular schwannoma resection in our hospital between November 2010 and December 2019 were retrospectively collected. According to the data collected retrospectively and the inclusion and exclusion criteria, we selected these patients and divided them into Group A (with preoperative gamma knife treatment) and Group B (without preoperative gamma knife treatment). The pre/postoperative clinical manifestations, neurological function grade, postoperative complications, tumor recurrence and increase were collected and compared between the two groups. There were 40 and 823 patients enrolled in Groups A and B, respectively. There were no significant differences in the general condition, tumor size and side, or neurological performance of the patients in those two groups before the operation. At the last follow-up, the number of patients with poor facial nerve function was 15 (39.5%) in Group A and 170 (20.7%) in Group B (P = 0.021 < 0.05). In Group A and Group B, disequilibrium occurred in 14 (36.8%) patients and 124 (15.1%) patients, respectively, after the operation (P = 0.012 < 0.05). Seven (17.5%) patients had pneumonia in Group A, and 21 (2.6%) patients had pneumonia in Group B (P = 0.04 < 0.05) after the operation. When a patient with vestibular schwannoma undergoes microsurgical surgery, the preoperative history with gamma knife treatment may make recovery from postoperative facial paralysis difficult for the patients, making them more prone to suffer from postoperative disequilibrium and postoperative pneumonia.

Predicting Extent of Microsurgical Resection of Sporadic Vestibular Schwannoma.

Develop a predictive model for incomplete microsurgical resection of sporadic vestibular schwannoma (VS). Historical cohort. Tertiary referral center. Patients with sporadic VS. Microsurgery with preoperative intent of gross total resection. Patient and tumor characteristics that influence extent of resection. Among 603 patients, 101 (17%) had intracanalicular tumors and 502 (83%) had tumors with cerebellopontine angle (CPA) extension. For patients with CPA tumors, 331 (66%) underwent gross total resection and 171 (34%) underwent near-total or subtotal resection (NTR-STR). Multivariable modeling identified older age at surgery, larger linear tumor size, and absence of a fundal fluid cap as predictive of NTR-STR ( p < 0.001). From this model, one can estimate that a 20-year-old with a tumor that has less than 10 mm of CPA extension and a present fundal fluid cap has a predicted probability of NTR-STR of 0.01 (or 1%), whereas a 70-year-old with a tumor that has 30 mm or greater CPA extension and absence of a fundal fluid cap has a predicted probability of NTR-STR of 0.91 (or 91%). Among the 171 patients who underwent NTR-STR, 24 required secondary treatment at the time of last follow-up. The primary predictors of incomplete microsurgical resection of VS include older age at surgery, larger linear tumor size, and absence of a fundal fluid cap. These factors can be used to estimate the likelihood of NTR-STR, aiding in preoperative discussions regarding future surveillance and potential need of secondary treatment, as well as shared clinical decision making.

Preservation of facial nerve function after resection of vestibular schwannoma

The objective of this study was to provide a comprehensive assessment of reported outcomes for facial nerve preservation after vestibular schwannoma surgery. Most data regarding facial nerve function in patients undergoing microsurgical resection of vestibular schwannomas predominantly include series performed at a single institution. In an effort to minimise individual surgeon or institutional bias, we performed an analysis of the published literature on facial nerve outcomes following microsurgical resection of vestibular schwannomas. Materials and methods. We identified a total of 296 studies involving over 25,000 patients that included outcome data for facial nerve function of vestibular schwannoma patients treated surgically. Data regarding surgical approach, tumour size, patient age, and use of intra-operative monitoring were extracted and correlated with facial nerve function after surgery. Patients with preoperative facial nerve dysfunction (House-Brackmann score III or higher) were excluded and ‘facial nerve preservation’ was defined as grade I or II House-Brackmann function at last follow-up visit. Results. A total of 79 articles reporting on 11,873 patients met our inclusion criteria contributing to our analysis. Patients treated with the middle cranial fossa approach had a trend towards higher overall facial nerve preservation rate (85 %), compared to the translabyrinthine approach (81 %, p = 0.07), and did statistically better than the retrosigmoid approach (78 %, p &lt; 0.0001). Patients with an average tumour size &lt; 20 mm had significantly improved facial nerve preservation rates, compared to larger tumours (90 % vs. 67 %, p &lt; 0.0001). Patients under 65 years of age had a lower facial nerve preservation rate (71 % vs. 84 %, p &lt; 0.001). Finally, the use of intra-operative monitoring improved the facial nerve preservation rate (76 % vs. 71 %, p &lt; 0.001). Conclusion. Factors that appear to be associated with facial nerve preservation after microsurgical resection of a vestibular schwannoma include tumour size &lt;20 mm, use of the middle fossa approach and use of neuromonitoring during surgery. These data provide a summary assessment of the published literature regarding facial nerve preservation after microsurgical resection of vestibular schwannoma.

Cochlear nerve continuity preservation during retrosigmoid ablative osteotomy of the internal auditory canal for advanced vestibular schwannomas

Ausgewertet wurden 86 Patienten mit einem retrosigmoidal mikrochirurgisch resezierten Vestibularisschwannom im Tumorstadium Koos II–IV. Es zeigte sich, dass im Bereich des inneren Gehörgangs in über 2/3 der Fälle der Nervus cochlearis dem elektroneurographisch leicht zu identifizierenden Nervus facialis in immer wiederkehrenden ähnlichen Verlaufsmustern folgte. Ausgehend vom Fundus erleichterte dies die frühzeitige Identifizierung und damit den Kontinuitätserhalt des Nervus cochlearis im Verlauf des inneren Gehörgangs. Dies war vor allem dann von Bedeutung, wenn ein sicherer Funktionserhalt aufgrund der Tumorgröße oder -formation trotz intraoperativer Ableitung somatosensorischer Potenziale nicht sicher gewährleistet werden konnte, aber die Möglichkeit einer späteren Hörrehabilitation mit einem Cochleaimplantat bestehen bleiben sollte. Präoperative Magnetresonanztomographie(MRT)-Sequenzen ergaben zwar in einigen Fällen einen Hinweis auf die möglichen Nervenverläufe, die intraoperative Darstellung im inneren Gehörgang war der MRT aber überlegen.

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

To determine the influence extent of resection and tumor characteristics on facial nerve (FN) outcomes following microsurgical resection of vestibular schwannoma (VS). Retrospective chart review. Tertiary referral center. Three hundred eighty-five patients who underwent VS microsurgical resection. Microsurgical VS resection. 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. 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). 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.

Neuromonitoring des N. cochlearis bei der Resektion des Vestibularisschwannoms mit simultaner Cochleaimplantation

Vestibular schwannomas (VS) are benign tumors that originate from the nerve sheath of one of the two vestibular nerves. VS can have asevere impact on everyday life of the patient and may lead to symptoms such as vertigo, hearing loss (e.g., as sudden deafness), deafness, and tinnitus. Treatment concepts include observational waiting with regular imaging control ("wait and scan"), radiotherapy, or surgical resection. Depending on the size of the tumor and status of functional hearing, the surgical approach may be retrosigmoidal, transtemporal, retrolabyrinthine, or translabyrinthine. The translabyrinthine approach always results in complete deafness due to opening of the bony labyrinth. If the nerve structure of the cochlear nerve is preserved, hearing rehabilitation with acochlear implant (CI) may be successful. In this article the surgical technique for microsurgical resection of VS using atranslabyrinthine approach with simultaneous cochlear implantation under intraoperative monitoring of the cochlear nerve by electrical stimulation is presented.

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

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. 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. 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. 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.

Intraoperative Auditory Brainstem Response Results Predict Delayed Sensorineural Hearing Loss After Middle Cranial Fossa Resection of Vestibular Schwannoma.

To identify intraoperative neurophysiologic measures predictive of delayed progressive sensorineural hearing loss in the operative ear after a middle fossa approach (MCF) for resection of vestibular schwannoma (VS). Retrospective review. Academic, tertiary referral center. Subjects with vestibular schwannoma who underwent a MCF microsurgical resection of VS were analyzed for individuals whose hearing was initially preserved but subsequently developed progressive sensorineural hearing loss in the operative ear. Thirty-seven patients were identified for whom audiologic and neurophysiologic data was available. Intraoperative neurophysiologic changes will correlate with delayed sensorineural hearing loss in the operative ear. Audiometric evaluations, intraoperative electrocochleography (ECoG), and auditory brainstem response (ABR) measures. Twenty-five subjects experienced stable hearing or hearing loss in the operative ear comparable to the contralateral ear. Twelve subjects suffered a significant increase in the hearing asymmetry between ears. Deterioration in the amplitude of wave V of the ABR persisting at the close of tumor resection correlated with delayed sensorineural hearing loss in the operative ear (p 0.02, 5% mean improvement in the stable hearing group, versus a 14% decline with progressive asymmetry), but changes in ECoG or other auditory brainstem response parameters (p > 0.05) were not predictive. Persisting amplitude reduction of wave V of the intraoperative ABR best correlates with delayed progressive sensorineural hearing loss in the operative ear. Neither persistent changes in ECoG, other ABR parameters, nor transient changes, correlated with delayed progressive sensorineural hearing loss in the operative ear.

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

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. Retrospective analysis. Tertiary referral center. Adult (≥18 yr) patients underwent translabyrinthine or retrosigmoid VS resection by a single neurotologist and single neurosurgeon between February 2008 and December 2017. Long-term FN outcomes (≥12 mo) according to House-Brackmann (HB) grade. 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). 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.

Clinical Predictors of Facial Nerve Outcomes After Surgical Resection of Vestibular Schwannoma.

To identify clinical predictors of facial nerve (FN) outcomes after microsurgical resection of vestibular schwannoma (VS). Prospective cohort study. Academic medical center. Consecutive patients undergoing VS resection from November 2017 to October 2019 were included. FN function was evaluated with the House-Brackmann (HB) scale and stratified into good (HB I-II) and poor (HB III-VI) function. Analyses included descriptive statistics, correlation, and logistic regression. Of 256 patients who met criteria (mean age, 47.7 years; 62.5% female), 227 (88.7%) achieved good FN function postoperatively and 238 (93.0%) at latest follow-up (mean, 154.8 days). Operative approaches consisted of translabyrinthine (50.8%), retrosigmoid (25.0%), and middle fossa craniotomies (24.2%). Extent of resection was decided intraoperatively, and gross or near total resection was accomplished in 237 (92.6%) cases. Postoperative HB grade correlated with latest HB grade (0.615, P < .001). Factors associated with good postoperative FN function included small tumor size (≤15 mm; odds ratio [OR], 2.425; P = .042), gross or near total resection (OR, 3.170; P = .041), and ≥100-µV intraoperative FN electromyographic response to a 0.05-mA stimulus (OR, 22.242; P < .001). Factors associated with good FN function at latest follow-up included gross total resection (OR, 7.764; P = .003) and ≥100-µV FN electromyographic response (OR, 8.518; P < .001), accounting for surgical approach and tumor size. Microsurgical resection of VS can be accomplished with excellent FN outcomes. Gross total resection and ≥100-µV intraoperative FN electromyographic response predicted excellent FN outcomes. Immediate postoperative FN function is a prognosticator of long-term FN function.

Microsurgical Resection of Vestibular Schwannomas, Presentation of Cases in 3D: 3-Dimensional Operative Video

Vestibular schwannomas are the most common benign tumors of the pontocerebellar angle,1,2 their microsurgical complexity is related to their size and neurovascular relationships. The purpose of this work is to analyze the clinical, anatomic characteristics, microsurgical treatment, and the postoperative results according to the Hannover gradual scale in 4 patients with vestibular schwannomas. The 4 patients gave their consent to the procedure and all consented to the use of their surgical videos, preoperative and postoperative studies, and postoperative pictures. Case 1: A 39-yr-old woman, with left ear hearing loss. Magnetic resonance imaging (MRI) showed small Intracanalicular schwannoma (T1 classification by Hannover). Microsurgery was performed and resection through a retrosigmoid approach2,3 with anatomic and functional preservation of the facial and cochlear nerve. Case 2: A 40-yr-old woman, with left ear hypoacusia. MRI showed an extrameatal schwannoma reaching the brainstem (T3b Hannover classification). The complete re-section through retrosigmoid approach were performed. Case 3: A 69-yr-old woman, without hearing in the right ear. RM: Medium schwannoma (T4a classification of Hannover). Microsurgery was performed with anatomic and functional preservation of the facial nerve.4-6 Case 4: A 32-yr-old woman, without hearing in the left ear. In addition, cerebellar syndrome and headache. RM: Large schwannoma (T4b classification of Hannover). Sur-gery was performed, anatomic preservation of the facial nerve, with moderate paresis in the postoperative period. Microsurgical resection with functional preservation of the facial and cochlear nerve is the main objective7 when addressing this pathology.

Time-based Assessment of Hearing Preservation Rates After Microsurgical Resection of Vestibular Schwannomas: A Systematic Review.

To determine short- and intermediate-term hearing preservation rates after microsurgical resection of vestibular schwannoma (VS). Systematic review of the Ovid, Cochrane, EMBASE, and Web of Science databases. This study was restricted to full-text English-language articles detailing VS resection via the middle cranial fossa or retrosigmoid approaches. Documentation of pre- and posttreatment hearing outcomes with American Academy of Otolaryngology-Head and Neck Surgery, Gardner-Robertson, or word recognition score scales, as well as time to follow-up were required. Duplicate data sets, studies with >10% of patients with neurofibromatosis two, previous or nonsurgical VS treatment, case reports with <five patients, or studies detailing decompressive surgery were excluded. Two authors independently performed full-text reviews to determine study eligibility. Discrepancies were settled by consensus. "Class A/B, I/II" hearing was defined as AAO-HNS Class A or B, Gardner-Robertson Class 1 or 2, or PTA ≤ 50 dB with word recognition score ≥ 50% on audiogram. Pooled estimates of preserved Class A/B, I/II hearing at last postoperative follow-up. Of 1323 reports, 14 were utilized in analyses yielding data from 2,977 patients. Mean follow-up was 52.5 months (SD = 19.9). Class A/B, 1/2 hearing was preserved at last follow-up in 57% of patients. Meta-regression revealed that resection through the middle cranial fossa was associated with preservation of serviceable hearing. Moreover, when preserved in the immediate postoperative period, it seems to be stable over time.

The Direct Costs of Microsurgical Resection of Vestibular Schwannomas.

To determine and itemize surgical costs associated with the translabyrinthine (TL), retrosigmoid (RS), and middle cranial fossa (MCF) approaches for microsurgical excision of vestibular schwannoma (VS). Retrospective cost analysis study. Tertiary referral center. Thirty consecutive adult patients underwent microsurgical excision of VS by either TL, RS, or MCF approach (10 per approach). Microsurgical excision of VS by one of the three major approaches. Medical and financial data were collected. Total operating room time (minutes), skin-to-skin time (minutes), operating room cost ($US), and surgical supplies cost ($US). The MCF approach was associated with the shortest skin-to-skin time (230.3 min, p < 0.001). Mean overall nonsurgical room time was 94.7 minutes and not significantly different among approaches (p = 0.55). Mean total surgical supplies cost was $5,028 and was the highest for the RS ($7,116; p < 0.001) but not significantly different between TL and MCF. Mean operating room services charges were $68,417 overall and were the lowest for the MCF group ($53,306; p = 0.01). Tumor size was not correlated with surgical supplies cost (p = 0.74). The items associated with the highest average cost per case were the surgical aspirator ($1,062), drill burs ($928), and titanium implants ($575). There was redundancy in multiple surgical items such as drill burs, hemostatic agents, and sutures. This study is the first to provide a detailed itemization of the surgical expenses specific to VS resection. Elevated nonsurgical room time and supply redundancy provides the opportunity for decreasing surgical costs and waste.

Durability of Hearing Preservation Following Microsurgical Resection of Vestibular Schwannoma.

To ascertain long-term hearing outcomes in patients with serviceable hearing following microsurgical resection of sporadic vestibular schwannoma (VS). Retrospective cohort. Tertiary academic referral center. Forty-three adult subjects with unilateral sporadic VS who had serviceable hearing (American Academy of Otolaryngology-Head and Neck Surgery [AAO-HNS] class A or B) on initial postoperative audiogram following microsurgical resection between 2003 and 2016 with a minimum of two postoperative audiograms available for review. Surgical treatment with a retrosigmoid or middle cranial fossa approach. Rate of maintaining serviceable hearing, as estimated using the Kaplan-Meier method, in accordance with the 1995 and 2012 AAO-HNS guidelines on reporting hearing outcomes. The median immediate postoperative pure-tone average (PTA) and word recognition score (WRS) were 31 dB and 95%, respectively. At last follow-up, the median PTA was 38 dB with a median change of 5 dB from initial postoperative audiogram, and the median WRS was 90% with a median change of 0% from initial postoperative audiogram. Eight patients developed non-serviceable hearing at a median of 4.1 years following microsurgical resection (interquartile range, 2.9-7.0). The median duration of hearing follow-up for the 35 patients who maintained serviceable hearing was 3.1 years (interquartile range, 2.2-7.5). Tumor control was achieved in 41 (95%) patients. The rate of maintaining serviceable hearing at 5 years was 81%. Microsurgical resection provides excellent tumor control and durable long-term hearing in those with AAO-HNS class A or B hearing postoperatively. The paradigm of proactive microsurgical resection-when the tumor is small and hearing is good-hinges on the surgeon's ability to preserve residual hearing in a very high percentage of cases at or near preoperative hearing levels to maintain an advantage over conservative observation with regard to long-term hearing preservation.

Pattern of cochlear obliteration after vestibular Schwannoma resection according to surgical approach.

To investigate the prevalence and course of cochlear obliteration according to microsurgical approach to inform clinical decision making regarding optimal timing of cochlear implantation. Retrospective radiologic review and chart review. Patients who underwent microsurgical resection of vestibular schwannoma (VS) with a minimum of two available postoperative magnetic resonance imaging (MRI) scans were analyzed. The prevalence and timing of cochlear and labyrinthine obliteration was classified using relevant MRI sequences. MRI studies in 60 patients were analyzed: 20 translabyrinthine (TL), 20 retrosigmoid, and 20 middle fossa (MF) cases. The first and last postoperative MRI was obtained a median of 3.4 months (interquartile range (IQR), 3.0-3.7 months) and 35 months (IQR, 27-83 months) after surgery, respectively. At the time of the first postoperative MRI, 21 (35%) patients had partial basal turn obliteration, and none of the patients had complete basal turn obliteration. At the time of the last postoperative MRI, six (10%) patients had partial basal turn obliteration and 17 (28%) patients had complete basal turn obliteration. The pattern of partial or complete basal turn obliteration differed significantly among all three surgical approaches (P < .001). Specifically, the risk of partial or complete obliteration of the basal turn was highest in the TL cohort and lowest in the MF cohort. The prevalence and timing of cochlear obliteration after VS microsurgery varies significantly according to surgical approach. The risk of early and complete obliteration is highest in the TL group and lowest in the MF cohort. These data may inform clinical decision making regarding optimal timing of cochlear implantation in patients with advanced hearing loss after microsurgical resection. 4 Laryngoscope, 130:474-481, 2020.