Translabyrinthine Approach Research Articles

Revised Classification of Inner Ear Schwannomas.

Over the past two decades, there has been increasing interest in the diagnosis and management of schwannomas of the inner ear including hearing rehabilitation with cochlear implants. However, tumor nomenclature and classification within the literature have been variable and oftentimes cumbersome. The term "intralabyrinthine schwannoma" is in common use when describing these tumors but is a potential source of confusion given that people often use the term "labyrinth" or "labyrinthine" to refer to the vestibular component of the inner ear only (i.e., labyrinthectomy or the translabyrinthine approach).During the Ninth Quadrennial Conference on Vestibular Schwannoma and Other Cerebellopontine Angle Lesions in Bergen, Norway, in May 2023, a multidisciplinary group of conference participants met and discussed issues pertaining to current terminology and classifications to enhance clarity and to reflect recent advances in tumor management and hearing rehabilitation.Although a variety of terms have been previously used to describe inner ear schwannomas, consensus was achieved on the term "inner ear schwannoma (IES)" to describe eighth nerve schwannomas of the cochlea, vestibule, or semicircular canals. Subgroups under this term comprise intravestibular, intracochlear, or intravestibulocochlear inner ear schwannomas (low complexity tumors), inner ear schwannomas with transfundal extension into the internal auditory canal but without modiolar involvement (intermediate complexity tumors), and inner ear schwannomas with transfundal extension with modiolar involvement (high complexity tumors).The details of the recommendations for an updated and simplified tumor nomenclature centered around tumor control and hearing rehabilitation with cochlear implantation are presented.

Translabyrinthine versus Retrosigmoid Approach for Vestibular Schwannoma: A Systematic Review and An Updated Meta-Analysis.

Several approaches can be used in the surgical treatment of vestibular schwannoma (VS), and the best approach remains uncertain in the literature. This systematic review and meta-analysis aim to compare the translabyrinthine approach (TLA) with the retrosigmoid approach (RSA) for VS in terms of postoperative complications. PubMed, Web of Science, Embase, and Cochrane. The primary outcome was cerebrospinal fluid (CSF) leak; secondary outcomes were facial nerve dysfunction (FND), length of stay (LOS), and meningitis. Statistical analysis was performed using RStudio 2024.04.1 + 748. Heterogeneity was assessed with I² statistics. We performed sensitivity analysis with subgroup analysis and meta-regression. Risk of bias was assessed using ROBINS-I. Out of 1140 potential articles, 21 met the inclusion criteria. Among the 4572 patients, 2687 and 1885 patients in the TLA and RSA groups, respectively. No significant differences were found in CSF leak (odds ratio [OR] 1.03; 95% confidence interval [CI] 0.81,1.32; P = .794) or meningitis (OR 1.05; 95% CI 0.45, 2.43; P = .73). Meta-regression showed no association with CSF leak and the number of cases per center or publication year. The TLA is associated with a shorter LOS (MD -1.20; 95% CI -1.39, -1.01; P < .01) and a higher chance of having and HB 4 or lower compared to patients who underwent RSA (OR 0.30; 95% CI 0.10, 0.89; P = .03). There was no difference in the odds of CSF leak or meningitis between the groups. In addition, the TLA has a shorter LOS and a higher chance of a better facial nerve outcome compared to the RSA.

Application and development of super minimally invasive surgery concept in acoustic neuroma resection

With the development of medicine, surgery has also experienced the development and evolution from traditional surgery to minimally invasive surgery, and then to super minimally invasive surgery (SMIS). Meanwhile, reducing surgical trauma and preserving and reconstructing nerve function have gradually become new goals of modern vestibular schwannoma (VS) resection surgery. The surgery of VS can be divided into hearing-preserving surgery (retrosigmoid approach and middle fossa approach) and non-hearing-preserving surgery (traditional translabyrinthine approach), according to whether the patient has practical hearing before operation. Improving the hearing preservation rate of hearing-preserving surgery and reconstructing the hearing of patients with non-hearing-preserving surgery are major challenges and hotspots. The traditional translabyrinthine approach has the highest proportion in the Department of Otolaryngology-Head and Neck Surgery, with the advantages of high facial nerve preservation rate and few intracranial complications. However, due to the resection of the cochlear nerve and labyrinth, the cochlea develops fibrosis, and patients lose the opportunity to reconstruct hearing through cochlear implantation. The new modified translabyrinthine approach can preserve the cochlear nerve and effectively reduce cochlear fibrosis, providing an opportunity for cochlear implantation to reconstruct the hearing. This is another important breakthrough in vestibular schwannoma surgery.

Predictors of Prolonged Hospital Stay After Microsurgery for Vestibular Schwannoma: Analysis of a Decade of Data.

Microsurgical resection is one of the treatments for vestibular schwannomas (VS). While several factors have been linked to increased length of stay (LOS) for VS patients undergoing microsurgery, a better understanding of these factors is important to provide prognostic information for patients. Determine predictors of increased LOS for VS patients undergoing microsurgical resection. Retrospective analysis using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2010 to 2020. Database review. All patients who underwent microsurgery (CPT codes 61520, 61526/61596) for the management of vestibular schwannoma (ICD9 and ICD10 codes 225.1, D33.3) were included. Analyzing perioperative factors that can predict prolonged hospital stay. A total of 2096 cases were identified and 1,188 (57%) of these patients were female. The mean age was 51.0 ± 14.0 years. Factors contributing to prolonged LOS included African American race (OR = 2.11, 95% CI: 1.32-3.36, p = 0.002), insulin-dependent diabetes mellitus (OR = 2.12, 95% CI: 1.09-4.4.11, p = 0.026), hypertension (OR = 1.26, 95% CI: 1-1.58, p = 0.046), functional dependency (OR = 5.22, 95% CI: 2.31-11.79, p = 0.001), prior steroid use (OR = 1.96, 95% CI: 1.18-3.15, p = 0.009), ASA class III (OR = 2.06, 95% CI: 1.18-3.6, p < 0.011), ASA class IV (OR = 6.34, 95% CI: 2.62-15.33, p < 0.001), and prolonged operative time (OR = 2.14, 95% CI: 1.76-2.61). Microsurgery by a translabyrinthine (TL) approach compared to a retrosigmoid (RSG) approach had lower odds of prolonged LOS (OR = 0.67, 95% CI: 0.54-0.82, p < 0.001). In a separate analysis regarding patients receiving reoperation, operative time was the only predictor of prolonged LOS (OR = 2.77, 95% CI: 1.39-5.53, p = 0.004.). Our analysis offers an analysis of the factors associated with a prolonged LOS for the surgical management of VS. By identifying healthcare disparities, targeting modifiable factors, and applying risk stratification based on demographics and comorbidities, we can work toward reducing disparities in LOS and enhancing patient outcomes.

Long-Term Outcomes of Modified Endoscopic Transcanal Approach to Small Acoustic Tumors.

The management options for small acoustic tumors are still controversial, and surgery is indicated in a select number of patients only. This is to avoid unnecessary extensive operations and risk of complications. Endoscopic transcanal approach, which was recently introduced, can be an alternative option to overcome these challenges. We have developed a modified technique for endoscopic transcanal removal of small acoustic tumors with tympanoplasty using tragal cartilage and without the need to harvest abdominal fat for obliteration. There was also no need to do an ear cul-de-sac procedure compared with the previous method. We report the long-term outcomes of this approach. Retrospective review. Tertiary hospital. Those who were diagnosed with small acoustic tumors between June 2016 and June 2022 were enrolled. Tumor removal via a Modified Endoscopic Transcanal Transpromontorial Approach (mETTA). Tumor control rate, closure rate of tympanic membrane, and complications such as cerebrospinal fluid (CSF) leakage and facial palsy were analyzed. Operation time and hospital stay were also analyzed. Twenty-two patients with a mean age of 55.5 ± 9.4 years were enrolled. Eighteen were vestibular schwannomas (VS), two were intracochlear schwannomas (ICS), and two were with intravestibulocochlear schwannomas (IVCS). Gross total removal was achieved in 21 cases. One had developed significant CSF leakage, and the other patient complicated with permanent facial palsy. The tympanic membrane healed well in all patients, but three patients showed delayed healing until several months and treated conservatively. Mean operation time was 149.6 ± 48.4 minutes, mean hospital stay was 8.9 ± 4.5 days, and mean postoperative follow-up period was 42.0 ± 15.7 months. Long-term results of modified endoscopic transcanal approach to small acoustic tumors are acceptable and comparable to classical treatments such as translabyrinthine approach or gamma knife radiation. This is an alternative option for smaller tumors warranting surgical removal and maintained cosmetic advantages.

A Proposal for Comprehensive Audio-Vestibular Test Battery Protocol for Diagnosis and Follow-Up Monitoring in Patients with Vestibular Schwannoma Undergoing Surgical Tumor Removal.

Background: A vestibular schwannoma (VS) is a benign tumor, causing audiological and vestibular symptoms. This study aimed to propose a comprehensive audio-vestibular test battery protocol for diagnosis and follow-up monitoring in patients with unilateral VSs undergoing surgical removal. Methods: The detailed interpretation of audiological and vestibular findings was presented in two example cases. The surgery was performed through the middle cranial fossa (#1) and translabyrinthine approach (#2). The participants were evaluated with tonal, speech, and impedance audiometry, ABR, caloric test, vHIT, cVEMP, oVEMP, SOT, and DHI. Patient and tumor characteristics were retrieved from the patient's history. Results: In the postoperative period, the reduction in gain of the lateral semicircular canal was observed in the vHITs of both patients. The DHI in case #1 increased after surgery, while it decreased in case #2. The improvement in postural performances compared to the preoperative SOT (CON 5, CON 6, composite score) and immediately after the procedure was observed. Conclusions: A specific diagnostic protocol is necessary to compare the results of different surgical techniques and approaches. Diagnostic tests performed before the surgery should be repeated within a specific time frame during postoperative follow-up to enable the comparison of results. The proposed protocol can help us better understand the processes ongoing during tumor growth and postoperative vestibular compensation.

Deskeletonizing the Sigmoid Sinus Is Noncompulsory in Skull Base Surgery: 3D Modeling of the Translabyrinthine Approach

Abstract Objectives Sigmoid sinus (SS) compression and injury is associated with postoperative SS occlusion and corresponding morbidity. Leaving the SS skeletonized with a thin boney protection during surgery might be favorable. This study quantifies the effect of the SS position on the operative exposure in the translabyrinthine approach and assesses the feasibility of retracting a skeletonized SS. Methods Twelve translabyrinthine approaches were performed on cadaveric heads with varying SS retraction: skeletonized stationary (TL-S), skeletonized posterior retraction (TL-R), and deskeletonized collapsing of the sinus (TL-C). High-definition three-dimensional reconstruction of the resection cavity was obtained. The primary outcome, “surgical freedom” (mm2), was the area at the level of the craniotomy from which the internal acoustic porus could be reached in an unobstructed straight line. Secondary outcomes include the “exposure angle,” “angle of attack,” and presigmoid depth. Results During TL-R, surgical freedom increased by a mean of 41% (range: 9–92%, standard deviation [SD]: 28) when compared to no retraction (TL-S). Collapsing the SS in TL-C provided a mean increase of 52% (range: 19–95%, SD: 22) compared to TL-S. In most cases, the exposure is the greatest when the SS is collapsed. In 40% of the specimens, the provided exposure while retracting (TL-R) instead of collapsing (TL-S) the sinus is equal or greater than 50% of other specimens in which the sinus is collapsed. Conclusion In cases with favorable anatomy, a translabyrinthine resection in which the skeletonized SS is retracted provides comparably sufficient exposure for adequate and safe tumor resection.

Delayed facial nerve palsy after vestibular schwannoma resection: risk factors, extent and prognosis.

Facial nerve palsies may develop during the postoperative period of microsurgical removal of vestibular schwannomas (VSs), even after normal facial function for days or weeks after surgery. The aim of this study was to identify the pathomechanism and predictive factors of delayed palsy. The clinical data of 193 patients who underwent vestibular schwannoma surgery between 2012 and 2021 were retrospectively analyzed. A total of 134 patients were included. The patients showed intact facial nerve function up to 24h after surgery. All patients (n = 20) with palsy from postoperative day 4 were included and collectively referred to as delayed facial nerve palsy (DFNP). Various factors were checked using a binomial regression analysis. The mean age of patients with DFNP was 57.8 years (55% female, 45% male). 70% had VS with KOOS ≥ 3, and 60% underwent surgery via a translabyrinthine approach Among the 16 patients with DFNP-related neurotropic pathogens, 25% were seropositive for herpes simplex virus. Most patients (n = 9/20) experienced onset of palsy between postoperative days 6 and 10. Of the four variables included in the significance test, three were significant: KOOS ≥ 3 (p < .04), ipsilateral vestibular organ failure (p < .05), and age group (p < .03). After therapy, 100% of patients recovered almost complete facial nerve function. The parameters mentioned above (KOOS classification and ipsilateral vestibular dysfunction) could be proven risk factors for the occurrence of DFNP.

Vestibular schwannoma microneurosurgery in patients over 70: a single institution experience and proposal of a treatment algorithm.

Elderly patients with vestibular schwannoma (VS) are commonly observed. Retrospective analysis of 25 patients aging ≥ 70 operated on in our neurosurgical department for unilateral VS. The purpose of our study is to propose an algorithm for the treatment of VS in elderly patients. American Society of Anesthesiology (ASA) Grade I-II patients and Grade III with life-threatening tumors were enrolled. Karnofsky Performance Status Scale (KPS) was used for evalutation of the quality of life. The House-Brackmann (HB) scale for facial nerve (FN) outcome was used. Tumor size was categorized according to Koos' classification. A retrosigmoid approach was used in all cases, except one in which a translabyrinthine approach was performed. Surgical removal graduation: total (GTR), near total (NTR > 95%), subtotal (STR > 90%). The clinical and radiological follow-up period was set first at six months and then at one year after surgery. FN results evaluation was performed at one year, categorized according to House-Brackmann grades I-VI. Mean age: 74,4years (70-83); 28% ASA I, 56% ASA II, 16% ASA III. Mean tumor size: 2,7cm (1,5-4,2cm). 68%, STR 32%. Mortality was zero. At last follow-up (one year after surgery) FN results were: HBI 81%, HBII 9.5%, HBIII 9.5%; HB IV 0%. Only 4 patients had preoperative HB IV, of whom one improved from HB IV to HB III. Transient complications occurred only in large VS. Re-growth of residue after STR was observed in 3 cases, treated with SRS in 2 cases and observed in 1. An algorithm of treatment of vestibular schwannoma in the elderly is proposed. In particular, in patients in general good conditions, age does not appear to be a major contraindication for microsurgery of VS. FN results at last follow-up are satisfactory and the complication rates are acceptable.

Customized Vestibular Rehabilitation for Vestibular Schwannoma Excision via Translabyrinthine Approach: A Single-Center Experience.

Objectives: To evaluate the effectiveness of intensive customized vestibular rehabilitation after vestibular schwannoma (VS) excision. Methods: 52 patients who underwent VS removal via a translabyrinthine approach from 2020 to 2022 were involved in this study. Bedside examination, video head impulse test (vHIT), functional head impulse test (fHIT), and the dizziness handicap inventory (DHI) were performed before and after the rehabilitation, which consisted of 10 sessions of specifically designed vestibular, visual, and physical integrated training. Results: After rehabilitation, the vHIT showed overall unchanged values on the affected and healthy side. In contrast, the scores of fHIT, which explores the higher connection of the vestibular system with visual and cerebellar pathways, improved on both the pathological and healthy sides after training (p-value 0.004 and 0.000, respectively). The effectiveness of the rehabilitation was reinforced by the DHI scores, which were considerably lower after training. Conclusions: To our knowledge, this is the first study to explore fHIT outcomes after removal of VS, estimating the impact of rehabilitation on the overall compensation process. The outcomes support the role of extensive postsurgical rehabilitation in the compensatory process, even just a few days after surgery.

Endoscopic transcanal facial nerve decompression in traumatic facial nerve palsy: A case series

Abstract Temporal bone fractures contribute to 7%–10% of patients suffering from facial nerve (FN) palsy.Traumatic facial paralysis is the most common cause of lower motor neuron facial paralysis, accounting for about 17% of its incidence. Temporal bone fractures contribute to 7%–10% of patients suffering from facial nerve (FN) palsy. The proximal tympanic segment of FN is most commonly affected in such cases. The classical microscopic surgeries for pathologies involving the FN, such as transmastoid approach, middle cranial fossa approach, and translabyrinthine approach, are associated with several disadvantages. The endoscopic transcanal approach is a minimally invasive surgery that can be used mostly for a lesion limited to the tympanic segment of the FN. It provides sufficient exposure for nerve decompression as compared to other approaches. Clear endoscopic vision of the tympanic cavity is also achieved, which is beneficial to ossicular chain reconstruction. Moreover, it causes minimal surgical trauma. Operating time and postoperative hospital stay are also reduced. This technique is cosmetically more acceptable to the patient. In this article, we report three cases of posttraumatic FN palsy where we performed endoscopic transcanal nerve decompression. It resulted in dramatic improvement of the facial palsy from House–Brackmann Grade IV or Grade V to Grade II immediately following surgery. The outcome of FN decompression through this approach was found to be comparable to conventional approach.

Surgical results for one-stage VII/VIII schwannoma resection and hemihypoglossal-facial neurorrhaphy

BackgroundThis retrospective study evaluated the outcomes of patients undergoing one-stage resection of VII/VIII schwannomas and hemihypoglossal-facial neurorrhaphy via the translabyrinthine approach (TLA). MethodsThe study encompassed ten consecutive patients with unilateral hearing loss (six women, four men, mean age: 49.5 ± 12.1 years) who underwent surgery. The cohort included two patients with vestibular schwannomas (VSs), four with facial nerve schwannomas (FNSs) (two originating from the geniculate ganglion of the facial nerve and two from the cerebellopontine angle), one with VS regrowth, and three with residual VSs. Preoperative facial nerve function, assessed using the House–Brackmann (HB) scale, was Grade V in one and Grade VI in nine patients. The mean preoperative duration of facial paralysis was 7.5 ± 6.9 months. ResultsAll patients underwent gross total resection. Postoperatively, one patient experienced cerebrospinal fluid leaks, which were successfully managed with lumbar drains and surgical revisions. At follow-up, facial nerve function improved in all patients: HB Grade V to III in one, HB Grade VI to III in one, HB Grade VI to IV in seven, and Grade VI to V in one. No tumor recurrence was observed during the follow-up period (mean duration: 16.6 ± 9.3 months), and no patient had hemilingual atrophy. ConclusionThe TLA for one-stage resection of VII/VIII schwannomas and facial nerve reconstruction is effective in treating both regrowth and residual VSs and FNSs in the cerebellopontine angle or petrosal bone in patients with severe preoperative facial palsy. This technique facilitates simultaneous tumor removal and nerve anastomosis, thereby reducing the need for multiple surgical interventions in patients with hearing loss and compromised facial nerve function.

The Extra-Extended Translabyrinthine Approach for Resection of Large Acoustic Neuroma: 2-Dimensional Operative Video.

The extended translabyrinthine approach to acoustic neuroma (AN) was created to allow improved visualization and access to larger tumors.1,2 The dural opening, however, remained confined to the presigmoid space. Other authors have introduced modifications to increase the dura exposure around the internal auditory canal (IAC).3-5 The extra-extended translabyrinthine approach was conceptualized by the senior author (CC) to maximize AN exposure and early cranial nerve identification. The tentorial peeling was added to allow extradural mobilization of the temporal lobe.6 This allows further safe bone removal around the IAC and petrous apex and consistent opening of the facial canal at IAC fundus. This modification creates 280-to-360-degree dura exposure at the IAC. The dural opening extends to the petrous apex superiorly and the prepontine arachnoid cistern inferiorly and includes resection of a tentorium dural flap created by the tentorial peeling.6 This exposure allows for near circumferential exposure of the tumor and early identification of the glossopharyngeal nerve in the cochlear aqueduct area, the trigeminal nerve at the porus trigeminal, and the facial nerve (FN) at IAC fundus. In addition, this ample exposure permits identification of the FN trajectory in the tumor capsule before any tumor dissection. We present a detailed video of extra-extended translabyrinthine approach technique in a patient with a large left AN (Hannover classification T4B).7 This video does not involve any human research projects not requiring Institutional Review Board/ethic committee approval. The patient consented to the procedure and to the publication of his image. Complete resection was obtained. The FN function was House-Brackman I/VI.

Translabyrinthine approach in acoustic neuroma surgery – case report

Introduction. Acoustic neuroma is a benign tumor that arises from the glial Schwann sheath junction of the vestibulocochlear nerve. It has an incidence of 1:100000 population. Despite the fact that this is a rare tumor, it accounts for approximately 6% of all intracranial tumors and 80% of tumors localized in cerebellopontine angle. Treatment of acoustic neuroma is represented by “Wait and Scan” monitoring, radiologic and surgical treatment. The latter remains the primary treatment for acoustic neuroma and consists of 3 main approaches: retrosigmoid approach, middle cranial fossa approach and translabyrinthine approach. Until now, in our country, acoustic neuroma surgery was done only by retrosigmoid approach. Case presentation. The first translabirinthine surgery for acoustic neuroma in our country was done on 09.12.2021 on a 60-year-old patient who, during preparation for cochlear implant surgery, was accidentally diagnosed with 3rd grade right acoustic neuroma, according to Koos classification. Patient had cophosis on the right ear and moderate hearing loss in the left ear. During the surgery, a gross total resection of the tumor was accomplished. The patient was discharged from the medical institution on 20.12.2021 in a satisfactory condition. Magnetic resonance imaging performed 3 months and 1 year after the surgery showed no complications or tumor remnants. Conclusion. The current report, which describes an accidental diagnosis of acoustic neuroma during preparation for a cochlear implantation surgery, resulted in acoustic neuroma surgery through the translabyrinthine approach. This serves as an eloquent example of why it is necessary to perform initially a magnetic resonance examination in cases of sensorineural hearing loss or tinnitus. The translabyrinthine approach in acoustic neuroma surgery allows for the removal of tumors of any size without affecting the brain, especially the cerebellum. In our case, where the patient had cophosis on the side of the tumor, this was the most appropriate surgical approach.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Translabyrinthine and Transcochlear Approaches

Abstract Introduction Skull base neuroanatomy is traditionally learned through two-dimensional anatomical atlases, which while are of unquestionable value, lack the nuanced association of three-dimensional relationships between fundamental anatomical structures relevant to surgical approaches. Surgically focused step-by-step anatomical dissections can augment trainee learning of complex skull base techniques, particularly multistep and nuanced techniques such as translabyrinthine and transcochlear approaches. Methods Translabyrinthine and transcochlear approaches were performed on six sides of three formalin-fixed latex-injected specimens. The study objective was the completion and photo documentation of the steps involved in the approach in order to provide a comprehensive, intelligible, and anatomically oriented resource for multilevel trainees. Illustrative case examples were prepared to supplement approach dissections. Results The translabyrinthine and transcochlear approaches offer unique lateral windows through the temporal bone into the posterior fossa, providing excellent access to pathology at the petrous apex, internal auditory canal, Meckel's cave, and anterolateral brainstem. The transcochlear approach, which is an anterior extension of the translabyrinthine, particularly provides excellent exposure of the prepontine region and clivus. Important surgical considerations include patient position, temporal bone drilling and identification of critical landmarks, dural opening and identification of neurovascular structures, and reconstruction/closure techniques. Conclusion The translabyrinthine and transcochlear approaches are fundamental techniques for lateral skull base and posterior fossa pathologies. Both approaches are hearing-sacrificing but often require minimal to no cerebellar retraction and deliver unique visualization of prepontine neurovascular structures. This step-by-step approach guide provides a unique practical and high-yield surgically oriented learning resource for neurosurgery and otolaryngology trainees.

Clinical Outcomes of Salvage Microsurgical Resection after Radiation Therapy for Sporadic Vestibular Schwannomas

Abstract Background The purpose of this study was to evaluate clinical outcomes after salvage microsurgery for vestibular schwannoma (VS) treated initially with modern radiotherapy techniques as compared to those treated with primary microsurgical resection. Methods Patients who underwent microsurgical resection of sporadic VS undergoing a translabyrinthine approach at a single academic skull base tertiary referral center were included. Baseline and postoperative dynamic gait index, functional gait assessment, House–Brackmann facial nerve grading, and completeness of resection were prospectively recorded. Results Of the 265 patients reviewed, 21 (7.9%) patients underwent prior radiation. Median age of the cohort was 55 years (interquartile range: 51–63). The likelihood of achieving a gross total resection was significantly lower for radiated as compared to nonradiated patients (odds ratio: 0.18, 95% confidence interval: 0.05–0.53, p = 0.004) when controlling for tumor size. Radiated patients had better postoperative facial nerve function on the first postoperative day, but this difference was not significant at long-term follow-up. Radiated patients had lower preoperative postural stability scores than nonradiated patients on FGA (26 vs. 23, p = 0.035). Postoperatively, radiated patients had comparable outcomes compared to nonradiated patients when controlling for age and tumor size. Conclusions Compared to patients with VS treated with surgery alone, previously radiated patients are less likely to achieve gross total resection in the salvage setting. Radiated patients scored better on facial nerve outcomes compared to nonradiated patients in the initial postoperative period but demonstrated similar long-term outcomes.

Translabyrinthine approach in surgical treatment of internal auditory canal lesions

The aim: to describe the microsurgical anatomy of translabyrinthine approach with a focus on the anatomy of the fundus of internal auditory canal (IAC), facial nerve, cochlea in cases of the IAC lesions; demonstrate the surgical technique on clinical cases. Materials and methods: We performed a cadaveric dissection study in March 2022. In total, 2 heads (4 sides) were dissected focusing on anatomical landmarks and surgical feasibility. Data from dissections were reviewed and analysed for further consideration. Features of translabyrinthine approch in different temporal bone pathology were demonstrated in cases of intracanal vestibular schwannoma, petrous bone supralabyrinthine cholesteatoma, meningioma. Results: The anatomy and features of the translabyrinthine approach in various pathologies of IAC are described. The attention is paid to the syntopy of IAC fundus (horizontal and vertical crests), facial nerve (FN), and cochlea. Removal of the lateral part of the horizontal ridge provides access to the lateral recess and the cochlear nerve. However, when expanding access in the anterior-superior direction and removing the bone between the tympanic and labyrinth segments of the FN, it is possible to open the 2nd turn of the cochlea. The point 1 mm below the labyrinthine segment of FN and 1.2-1.4 mm posterior to the FN tympanic segment approaches the scala vestibule at the level of the transition of the ascending part of the basal turn to the middle cochlea. Conclusion: The pathology of IAC is diverse and is represented by neoplasms of different types and histological structure. Surgical treatment of IAC pathologies is similar and is based on the same anatomical location and the necessity to prevent similar intra- and postoperative complications. The translabyrinthine approach is the standard and widest approach in the treatment of IAC pathology, which makes it possible to control the facial nerve throughout the temporal bone, to fully visualize the area of the lateral recess of the IAC fundus. To preserve the cochlear potential it is rational to use the method of introducing a test-electrode into the lumen of the cochlea. Цель. При патологии внутреннего слухового прохода (ВСП) описать микрохирургическую анатомию транслабиринтного доступа с фокусом на анатомию дна ВСП, лицевого нерва, улитки; продемонстрировать хирургическую технику на примере клинических случаев. Материалы и методы. Диссекционное исследование на кадаверных головах было выполнено в марте 2022г. Хирургическая диссекция транслабиринтного доступа с фокусом на антомические ориентиры и возможность выполнения доступа была изучена на 2 кадаверных головах (4 стороны). Особенности техники доступа продемонстрированы на примере клинических случаев пациентов с интраканальной вестибулярной шванномой, супралабиринтной холестеатомой пирамиды височной кости, менингиомой. Результаты. Описана анатомия и особенности выполнения транслабиринтного доступа при различных патологиях ВСП. Отдельное внимание уделено синтопии дна ВСП (горизонтального и вертикального гребней), лицевого нерва, улитки. Спиливание латеральных отделов горизонтального гребня предоставляет доступ к латеральному карману и улитковому нерву. Однако, при расширении доступа в передне-верхнем направлении и снятии костного массива в углу между тимпанальным и лабиринтным отделом лицевого нерва возможно вскрытие 2-ого завитка улитки. Точка на 1 мм ниже лабиринтного отдела нерва и на 1,2-1,4 мм кзади от тимпанального сегмента нерва соответствует вестибулярной лестнице на уровне перехода восходящей части базального завитка в средний завиток улитки. Заключение. Патология ВСП разнообразна и представлена разными по своему типу и гистологическому строению новообразованиями. Хирургическое лечение патологий ВСП схоже и базируется на одной анатомической локализации и необходимости профилактики схожих интра- и послеоперационных осложнений. Транслабиринтный доступ является стандартным и наиболее широким доступом при лечении патологии ВСП, позволяющим контролировать лицевой нерв на всем протяжении в височной кости, полностью визуализировать область латерального кармана дна ВСП. Для сохранения кохлеарного потенциала рационально использование метода введения в просвет улитки тестового электрода.

A Retrospective Analysis of Temporal Lobe Gliosis after Middle Fossa Resection of Small Vestibular Schwannomas.

The middle cranial fossa (MCF) approach is a well-established procedure in surgery of the internal auditory canal, as well as with the retrosigmoid and translabyrinthine approaches. It is commonly used in the hearing-preserving microsurgery of small vestibular schwannomas (VS). The debate about the "best" approach for the microsurgery of small VS without contact to the brainstem is controversial. It has been stated that the MCF approach leads to irreversible damage to the temporal lobe, which may be evident in follow-up magnet resonance imaging (MRI) as gliosis in up to 70% of patients. This study represents a retrospective chart analysis conducted at a tertiary university hospital. Here, 76 postoperative MRIs were re-evaluated by an experienced neuroradiologist and compared with the preoperative images. Temporal lobe gliosis was classified on an ordinal scale as absent, slight, moderate or severe. Occurrence of gliosis was matched to the clinical predictors (tumor stage, tumor volume, sex, age, and side). No case of severe or moderate gliosis was found in the patient group. Slight gliosis of the temporal lobe was rare and was only detected in four patients (5%). There was no relation between clinical predictors and the incidence of gliosis. In our cohort, postoperative MR imaging did not reveal relevant damage to the temporal lobe parenchyma. This confirms the safe concept of microsurgery of small tumors via the middle fossa approach. The severe glioses described in other studies may be caused by a forced insertion of the retractor or by more extended approaches. However, further prospective neurocognitive studies seem to be necessary in order to assess functional changes in the temporal lobe.

Prevalence and patterns of cerebral venous sinus thrombosis following vestibular schwannoma surgery: a systematic review and meta-analysis.

Cerebral venous sinus thrombosis (CVST) is a potentially serious complication following surgical treatment of vestibular schwannoma, a benign tumor originating from Schwann cells of the vestibulocochlear nerve. This study aimed to determine the prevalence of CVST following surgical treatment of vestibular schwannoma and the factors contributing to its occurrence. Two independent researchers searched the global databases of PubMed, Web of Science, Scopus, and the Cochrane Library up to September 01, 2023. We employed a random-effects model for data analysis. Heterogeneity was evaluated using the I2 test. To assess the quality of the studies meeting our inclusion criteria, we employed the Joanna Briggs Institute Critical Appraisal Checklist. We included 23 articles in this meta-analysis. The pooled prevalence of CVST after vestibular schwannoma surgery was 6.4% (95%CI 3.4-11.5%). The pooled prevalence of CVST following the retrosigmoid (RS), translabyrinthine (TL), and middle cranial fossa (MCF) approaches was 4.8% (95%CI 2.0-11.0%), 9.6% (95%CI 4.3-20.3%) and 9.9% (95%CI 1.6-42.2%), respectively, revealing a significant difference between the TL and the RS approaches (Odds ratio=2.10, 95%CI 1.45-3.04, P< 0.001).The sigmoid sinus exhibited the highest post-operative thrombosis rate (7.9%), surpassing the transverse sinus (3.7%) and involvement of both sigmoid and transverse sinuses (1.6%), respectively. No significant associations were found with demographic or surgical factors. In the current meta-analysis, we identified a 6.4% CVST prevalence following vestibular schwannoma surgery, with varying rates depending on the surgical approach. No significant associations with patient or surgical factors were found, emphasizing the need for heightened clinical vigilance and further research in this context. PROSPERO ID: CRD42023453513.

Audiometric Outcomes of Auditory Brainstem Implantation during Vestibular Schwannoma Resection in NF2 Patients

Abstract Background Many patients with neurofibromatosis type 2 (NF2) suffer from sensorineural hearing loss, and associated cochlear nerve compromise in NF2 patients makes auditory brainstem implant (ABI) an attractive treatment option. The long-term outcomes and benefits of the device are still being explored. Methods A retrospective review was conducted for 11 ABI recipients at a single-institution tertiary center between November 2017 and August 2022. Patients diagnosed with NF2 undergoing resection for concurrent vestibular schwannoma (VS) were included. Pre- and postaudiometric assessments were reviewed. Evaluation included pure-tone audiometry and speech testing. Results Our cohort included 11 patients with a median age of 34 years. All patients underwent a translabyrinthine approach for implant placement with concurrent VS resection. Average tumor size of VS was 2.87 cm. Preoperatively, 8 patients had pure-tone averages with no response at 110 dB, 2 were within mild–moderate hearing loss (25–45 dB), and one patient had a PTA of profound loss (92 dB). Postoperatively, 9 (81%) patients had improvement in PTA. In total, seven patients reported mild side effects upon ABI activation which included dizziness (n = 2), tinnitus (n = 1), and abdominal and lower extremity tingling sensation (n = 3). Of the seven patients with early speech perception (ESP) scores, five had a score &gt;75%, indicating the auditory ability to detect pattern perception upon auditory stimulation through the ABI alone. Conclusion Nine of 11 patients derived benefits from ABI placement. These findings demonstrate that ABI placement during concurrent VS resection can provide a significant hearing benefit for NF2 patients.