Surgical Treatment Of Vestibular Schwannomas Research Articles

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.

소규모 기관의 전정신경초종의 수술 결과

Background: This study aims to evaluate retrospectively the surgical outcomes and associated complications of vestibular schwannoma in a low-volume, single-center institution. We intend to discuss strategies that may improve clinical outcomes in the surgical treatment of vestibular schwan-noma in low-volume medical centers and the correlation between the case volume of medical center and clinical outcomes.&#x0D; Materials and Methods: From January 2018 to December 2022, 13 patients (5 males and 8 fe-males; median age, 66 years) underwent surgery for vestibular schwannoma. The surgeries were performed by a single surgeon who initiated the clinical practice. The median length of tumors was 35 mm (range, 13-55 mm).&#x0D; Results: Among 13 patients, 10 patients (76.9%) underwent retromastoid suboccipital craniotomy, 3 patients (23.1%) underwent translabyrinthine approach, 4 patients (30.8%) underwent subtotal resection, 6 patients (46.2%) underwent near-total resection, and 3 patients (23.1%) underwent gross total resection. The facial nerve preservation rate was 84.6% (n = 11). Hearing preservation rate was 30.7% (n = 4).&#x0D; Conclusions: The surgical outcomes of vestibular schwannoma are not directly influenced by the volume of the medical institution. Instead, they are dependent on factors such as proper surgical planning, appropriate selection of surgical approaches and using intraoperative monitoring.

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.

How to position the patient? A meta-analysis of positioning in vestibular schwannoma surgery via the retrosigmoid approach.

Patient positioning is a matter of ongoing debate in the surgical treatment of vestibular schwannoma (VS). Main endpoints of this discussion are preservation of facial nerve functioning, extent of resection, and complications. In this meta-analysis, we aim to investigate the impact of patient positioning on VS surgery via the retrosigmoid approach. We searched for eligible comparative trials on PubMed, Cochrane library, and Web of Science. Positioning groups were compared regarding facial nerve outcome, extent of resection, postoperative hydrocephalus, postoperative CSF leaks, perioperative venous air embolism, and perioperative mortality. Two groups of positions were defined, and the following positions were allocated to those groups: (1) Semi-sitting and Sitting-position; (2) Lateral position, supine position with extensive head rotation, lateral oblique (=Fukushima/Three-quarter prone), and park-bench position. From 374 full-text screenings, 7 studies met the criteria and were included in our meta-analysis comprising 1640 patients. Our results demonstrate a significantly better long-term (≥6 months) outcome of the facial nerve after VS surgery in the semi-sitting positioning (OR: 1.49, 95%CI: 1.03-2.15, p = 0.03). Positioning did not influence the extent of resection, rate of postoperative CSF leaks, and the presence of a postoperative hydrocephalus. Overall incidence of venous air embolisms was significantly associated with VS surgery in sitting positioning (OR: 6.77, 95% CI: 3.66-12.54, p < 0.00001). Perioperative mortality was equal among both positioning groups. Semi-sitting positioning seems to be associated with an improved facial nerve outcome after VS surgery via the retrosigmoid approach. Venous air embolisms are significantly more often observed among VS patients who underwent surgery in the sitting position, but the perioperative mortality is equal in both positioning groups. Both positioning groups are a safe procedure. Multicentric prospective randomized trials are needed to evaluate the risk-benefit ratio of each positioning in VS surgery via the retrosigmoid approach.

Novel Multiportal Approach to the Internal Auditory Canal for Hearing-Preserving Surgery: Feasibility Assessment in Dissections

State-of-the-art, minimally invasive endoscopic transcanal surgery of the internal auditory canal (IAC) sacrifices the cochlea with complete hearing loss. With a combination of the transcanal infracochlear and transmastoid retrolabyrinthine approaches, we aim to preserve hearing and enable minimally invasive surgical treatment of vestibular schwannoma. In this study, we investigate the anatomical indications and the feasibility of both approaches in dissections, in human whole head specimens. We operated whole head anatomical specimens with a four-handed technique, using the retrolabyrinthine approach as the main surgical corridor and the infracochlear approach for endoscopic visualization. We tested 4 different powered surgical systems. We collected intraoperative data on the size of the access windows, the surgical freedom, and the exposed area of the IAC. Finally, we evaluated the outcome in postoperative computed tomography scans. Six out of 14 sides were anatomically suitable and qualified for the surgery based on preoperative computed tomography. In all attempted sides, the IAC could be reached and opened, leaving the ossicular chain and the labyrinth intact. 51%-75% of the length and 22%-40% of the circumference of the IAC could be exposed. All tested instruments were beneficial at different stages of the surgery. The four-handed technique enabled good maneuverability of the instruments. The combined multiportal approach to the IAC is feasible with a good surgical exposure and full anatomical preservation of hearing. State-of-the-art surgical instruments in specimens with suitable anatomy are sufficient to perform this approach.

Phenotypical Variability of the Internal Acoustic Canal in the Middle Cranial Fossa Surgery.

Introduction The wide range of anatomical variability of the structures of the middle cranial fossa (MCF) and the lack of reliable surgical landmarks contribute to a high level of complications in the surgical treatment of vestibular schwannomas. We hypothesized that the cranial phenotype influences the shape of the MCF, the orientation of the pyramid of the temporal bone, and the relative topography of the internal acoustic canal (IAC). Methods The skull base structures were studied on 54 embalmed cadavers and 60 magnetic resonance images of the head and neck by photo modeling, dissection, and three-dimensional analysis techniques. By the value of the cranial index, all specimens were subdivided into dolichocephalic, mesocephalic, and brachycephalic groups for comparison of variables. Results The length of the superior border of the temporal pyramid (SB), the apex to squama distance, and the width of the MCF all peaked in the brachycephalic group. The value of the angle between the SB and the axis of the acoustic canal varied from 33 to 58 degrees; it peaked in the dolichocephalic group and showed its smaller value in the brachycephalic one. The pyramid to squama angle had reversed distribution and dominated in the brachycephalic group. Conclusion The cranial phenotype influences the shape of the MCF, temporal pyramid, and IAC. Presented in this article data help specialists operating on the vestibular schwannoma to localize the IAC based on the individual shape of a skull.

Simultaneous Surgical Treatment of Vestibular Schwannoma and Hemifacial Spasm via Minimally Invasive Retrosigmoid Approach

The combination of vestibular schwannoma (VS) and hemifacial spasm (HFS) caused by a vascular loop is not frequently encountered. Surgical intervention using the retrosigmoid approach may enable the two diseases to be treated simultaneously. A 68-year-old male presented with progressive right HFS. MRI revealed a concurrent vascular loop and 3.2-mm intracanalicular VS. The retrosigmoid approach, together with microvascular decompression, was used to remove VS. Intraoperatively, compression by the vascular loop alone induced HFS although it was not related to VS. This finding is in contrast to the literature reports in which VS has been implicated in HFS. In our patient, when VS was completely removed, HFS immediately disappeared postoperatively.

Application of Subperineural Resection Technique in Vestibular Schwannomas: Surgical Efficacy and Outcomes in 124 patients.

ObjectiveWe aimed to explore the application and prospects of the subperineural resection technique for tumor separation and removal under the perineurium during surgery for vestibular schwannomas (VSs).MethodsThis study retrospectively analyzed 124 patients with VSs who underwent surgery via a retrosigmoid approach from July 2015 to October 2020 in the Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University. The data will be discussed with regard to the following aspects: clinical features, surgical strategies, tumor resection extent, facial–acoustic function preservation, and postoperative complications.ResultsGross total resection (GTR) of the tumor was achieved in 104 patients, with a GTR rate of 83.9%, and subtotal resection (STR) of the tumor was achieved in 20 patients. There was no significant difference in facial and acoustic nerve functional preservation between GTR and STR, as well as in tumor resection between solid and cystic tumors. The retention rate reached 97.6% in terms of complete anatomical facial nerve preservation. Facial nerve function was assessed using the House–Brackmann (HB) grading score. Consequently, HB grades of I–II, III–IV, and V–VI were determined for 96 (77.4%), 25 (20.2%), and 3 (2.4%) cases, respectively, 1 week postoperatively and accounted for 110 cases (88.7%), 13 cases (10.5%), and 1 case (0.8%), respectively, at 6 months. Fifteen of 35 (42.9%) patients with serviceable hearing before the operation still had serviceable hearing at 6 months postoperatively. There were 5 cases of cerebellar or brainstem bleeding after the operation, and one patient died. Multivariate logistic regression analysis showed that older age (≥60 years, p = 0.011), large tumor (>3 cm, p = 0.004), and cystic tumor (p = 0.046) were independent risk factors associated with the extent of adhesion between the tumor and the brainstem and facial–acoustic nerve.ConclusionWe successfully applied the subperineural resection technique to a large series of patients with VSs and achieved satisfactory results. Accurate identification of the perineurium and subperineural resection of the tumor can effectively reduce the disturbance of the facial–acoustic nerve during the operation and provide an intuitive basis for judging the tumor boundary. The subperineural resection technique may be conducive to improving the rate of total tumor resection and facial–acoustic nerve functional preservation in the surgical treatment of VSs.

Postural stability and handicap of dizziness after preoperative vestibular ablation and vestibular prehabilitation in patients undergoing vestibular schwannoma resection.

Surgical treatment of vestibular schwannoma (VS) leads to acute ipsilateral vestibular loss if there is residual vestibular function before surgery. To overcome the sequelae of acute ipsilateral vestibular loss and to decrease postoperative recovery time, the concept of preemptive vestibular ablation with gentamicin and vestibular prehabilitation before surgery has been developed ("vestibular prehab"). Studying postural stability during walking and handicap of dizziness over a 1-year follow-up period in VS patients undergoing vestibular prehab before surgical treatment of VS. A retrospective review of consecutive patients with a diagnosis of a VS undergoing surgical therapy from June 2012 to March 2018 was performed. All patients were included with documentation of the length of hospital duration and the Dizziness Handicap Inventory (DHI) and the Functional Gait Assessment (FGA) assessed preoperatively as well as 6 weeks and 1 year postoperatively. A total 68 VS patients were included, of which 29 patients received preoperative vestibular ablation by intratympanic injection of gentamicin. Mean VS diameter was 20.2 mm (SD 9.4 mm) and mean age at surgery was 49.6 years (SD 11.5 years). Vestibular prehab had no effect on DHI and FGA at any time point studied. We found no effect of vestibular prehab on postural stability during walking and on the handicap of dizziness. These findings add to the body of knowledge consisting of conflicting results of vestibular prehab. Therefore, vestibular prehab should be applied only in selected cases in an experimental setting.

Clinical outcomes of resecting scarpa's ganglion during vestibular schwannoma surgery

Vestibular schwannomas are slow-growing tumors arising from the Schwann cells of the vestibular nerve. Scarpa’s ganglion, the vestibular nerve ganglion, is located within the internal auditory meatus. Surgical treatment of vestibular schwannomas carries the potential of resecting Scarpa’s ganglion along with the tumor. No prior studies have evaluated outcomes based on the presence of Scarpa’s ganglion within tumor specimens. The neurosurgery patient records were queried for patients who underwent surgical resection of vestibular schwannomas at the University of Missouri Healthcare between January 1, 2008 and December 31, 2018. Inclusion criteria consisted of minimum age of 18, imaging demonstrating an eighth nerve tumor, surgical resection thereof, and a final pathological diagnosis of WHO grade I schwannoma. Data were collected retrospectively. The histological slides of the tumors were reviewed, and the presence or absence of the ganglion was noted. Outcomes analyzed included postoperative dizziness, hearing, and facial nerve function. Fifty-two patients met inclusion criteria. Ten (19%) resected tumors contained portions of the ganglion. No difference in risk of resection of ganglion occurred based on the surgical approach (p = 0.2454). Mean follow-up duration was 24.6 months ± 26.2 standard deviation. No differences in postoperative hearing or dizziness (p = 0.8483 and p = 0.3190 respectively) were present if Scarpa’s ganglion was resected. House-Brackmann classification of facial nerve function at last follow-up was similar (p = 0.9190). Resection of Scarpa’s ganglion with vestibular schwannomas does not increase risk of post-operative dizziness, facial nerve weakness, or hearing loss.

The evaluation of vestibular compensation by vestibular rehabilitation and prehabilitation in short-term postsurgical period in patients following surgical treatment of vestibular schwannoma.

Vestibular schwannoma removal causes unilateral vestibular deafferentation, which results in dizziness and postural unsteadiness. Vertigo and balance problems together are among the most important aspects affecting quality of life. Intensive vestibular rehabilitation, which starts before surgery, with following postsurgical supervised rehabilitation, using visual biofeedback propose an instrument to accelerate a recovery process. Another option how to accelerate the vestibular compensation, is employment of presurgical gentamicin ablation together with vestibular rehabilitation (prehabilitation) of vestibular function. Purpose of present study was to examine the dynamics of vestibular compensation process using supervised intensive vestibular rehabilitation with visual biofeedback in the short-term postsurgical period. The second aim was to compare both studied groups mainly to evaluate if prehabilitation has potential to accelerate the compensation process in the early postoperative course. The study included 52 patients who underwent the retrosigmoid vestibular schwannoma removal. They were divided into two groups. The first group was prehabilitated with intratympanic application of gentamicin before surgery to cause unilateral vestibular loss (14 patients), the second group (38 patients) was treated in standard protocol without prehabilitation. All patients underwent at home vestibular training before surgery to learn new movement patterns. Following the surgery supervised intensive vestibular rehabilitation including visual biofeedback was employed daily in both groups between the 5th and 14th postoperative day. Outcome measurements included an evaluation of subjective visual vertical (SVV), posturography and the Activities-Specific Balance Confidence Scale (ABC). ANOVA for repeated measurements was used for statistical analysis. We observed significant improvement in SVV (p < 0.05), posturography parameters (p < 0.05) and ABC scores (p < 0.05) with postoperative rehabilitation program following surgery in both groups. There was no statistically significant difference between group treated by prehabilitation and group without prehabilitation. Results of this study showed that intensive postsurgical rehabilitation represents key factor in compensation process following retrosigmoid vestibular schwannoma surgery. Prehabilitation did not speed up recovery process.

Surgical treatment of large vestibular schwannomas in patients with neurofibromatosis type 2: outcomes on facial nerve function and hearing preservation.

Surgical treatment of vestibular schwannoma (VS) in patients with neurofibromatosis type 2 (NF2) along with functional preservation of cranial nerves is challenging. The aim of this study was to analyze the outcomes of hearing and facial nerve function in patients with NF2 who underwent large-size VS (> 2cm) surgery. From 2006 to 2016, one hundred and forty NF2 patients were included with 149 large-size VS resections using retrosigmoid approach. Hearing function was classified according to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria. Preoperative and one-year postoperative facial nerve function were both assessed using the House-Brackmann (H-B) grading scale. A multivariate logistic regression was performed to identify preoperative predictors for facial function outcomes. No operative death we noted. Total tumor removal was achieved in 82.6% of the operated VSs. The anatomical integrity of the facial nerve was preserved in 67.8% of surgeries. Good facial nerve function (H-B Grades I-III) was maintained in 49.6% of patients at 12months after surgery. Tumor size larger than 3cm and preoperative facial weakness related with worse outcome of facial nerve function (P < 0.001; for both). Hearing preservation surgeries were attempted in 31 ears. Class B or C hearing according to the AAO-HNS criteria was maintained in 7 ears (22.5%), and measurable hearing was maintained 11 ears (35.5%). It is challenging to maintain hearing and facial nerve function in NF2 patients with large VSs. Early surgical intervention is an appropriate choice to decrease the risk of neurological functions deficit.

Assistance with multimodal image fusion in surgery of vestibular schwannomas

Objective To discuss the assistance with multimodal image fusion technology in surgery of vestibular schwannomas to improve the rate of total resection as well as preservation of nerve function and achieve precise surgical treatment. Methods This retrospective study involved 30 patients who underwent surgical treatment of vestibular schwannomas with the assistance of multimodal image fusion at Neurosurgery Department of PLA General Hospital from January 2016 to August 2016. The facial nerve was reconstructed through Fast Imaging Employing Steady State Acquisition With Cycled Phases (FIESTA-C) and Diffusion Tensor Imaging (DTI), and the accuracy of reconstructed facial nerve was verified by intraoperative findings under microscope. The images of facial nerve, internal auditory canal water imaging and temporal bone CT were 3D-reconstructed and fused to determine the relationship between tumors and surrounding structures. CT navigation was used to determine the exact location of posterior wall of the internal auditory canal and areas to be removed. Continuous intraoperative neuroelectrophysiological monitoring was conducted to determine the location of the nerve to avoid its injury. Results Total tumor resection was achieved in 28 cases (93.3%) and subtotal resection in 2 cases (6.7%). The anatomical integrity of facial nerve was preserved in 28 cases (93.3%), and 26 cases (86.7%) had excellent or good facial functions. The successful rate of facial nerve reconstruction was 100%, and 93.3% of all patients demonstrated consistence between reconstructed and actual positions of the nerve. Navigation was performed in 17 patients with the registration error ranging from 0.30 mm to 0.92 mm (mean: 0.47±0.15 mm). None of the patients had preoperative functional hearing, and no one retained or improved hearing postoperatively. During the perioperative period, there was no death, cerebrospinal fluid leakage, intracranial hematoma or lower cranial nerve palsy. Conclusion The application of multimodal image fusion in surgical treatment of acoustic neuromas could improve the rates of total resection and facial function retention and help reduce operative complications. Key words: Neuroma, acoustic; Neuronavigation; Diffusion tensor imaging; Neurophysiology monitoring; Facial nerve; Internal auditory canal

Surgical Treatment of Vestibular Schwannoma: Does Age Matter?

For older patients (>65 years) who undergo surgical treatment of vestibular schwannoma (VS), the reported rates of facial nerve preservation, hearing preservation, and complications are inconsistent. Many surgeons believe that older patients have worse outcomes than their younger counterparts and advise against surgical treatment. We analyzed a consecutive series of patients with VS treated with surgery to determine whether age was a factor in outcome. We retrospectively reviewed all patients treated for VS at our institution from January 1, 2000, to July 1, 2012. We examined how sex, age (≥65 years and <65 years), race, tumor size, tumor laterality, body mass index, Charlson Comorbidity Index, smoking status, surgical approach, and preoperative hearing and symptoms were associated with outcomes. Two-hundred forty-three patients underwent resection of VS, including 23 patients ≥65 years (mean 68 ± 4 years) and 220 patients <65 years (mean 47 ± 11 years). The average tumor size was 16.5 mm. Older patients had a significantly lower body mass index of 26.6 vs. 29.8 (P= 0.03) and were more likely to have a CCI ≥2 (52.2% vs. 18.2%, P ≤ 0.00, preoperative facial numbness (34.8% vs. 10.1%, P= 0.03), and dizziness (78.3% vs. 49.3%, P= 0.03). There were no significant differences after surgery in facial nerve outcome, hearing preservation outcome, or general surgical complications between the 2 cohorts. With no difference in surgical complications, facial nerve outcome, or hearing preservation rates between older and younger patients in our series, age alone may not be an absolute contraindication to surgical management of VS.

A Patient-Assessed Morbidity to Evaluate Outcome in Surgically Treated Vestibular Schwannomas

Outcome after treatment of vestibular schwannomas can be evaluated by health providers as mortality, recurrence, performance, and morbidity. Because mortality and recurrence are rare events, evaluation has to focus on performance and morbidity. The latter has mostly been reported by health providers. In the present study, we validate 2 new scales for patient-assessed performance and morbidity in comparison with different outcome tools, such as quality of life (QOL) (European Quality of Life-5 dimensions [EQ-5D]), facial nerve score, and work capacity. There were 167 total patients in a retrospective (n= 90) and prospective (n= 50) cohort of surgically treated vestibular schwannomas. A new patient-assessed morbidity score (paMS), a patient-assessed Karnofsky score (paKPS), the patient-assessed QOL (EQ-5D) score, work capacity, and the House-Brackmann facial nerve score were used as outcome measures. Analysis of paMS components and their relation to other outcomes was done as uni- and multivariate analysis. All outcome instruments, except EQ-5D and paKPS, showed a significant decrease postoperatively. Only the facial nerve score (House-Brackmann facial nerve score) differed significantly between the retrospective and prospective cohorts. Out of the 16 components of the paMS, hearing dysfunction, tear dysfunction, balance dysfunction, and eye irritation were most often reported. Both paMS and EQ-5D correlated significantly with work capacity. Standard QOL and performance instruments may not be sufficiently sensitive or specific to measure outcome at the cohort level after surgical treatment of vestibular schwannomas. A morbidity score may yield more detailed information on symptoms that can be relevant for rehabilitation and occupational training after surgery.

Vertigo Perception and Quality of Life in Patients after Surgical Treatment of Vestibular Schwannoma with Pretreatment Prehabituation by Chemical Vestibular Ablation.

Surgical removal of vestibular schwannoma causes acute vestibular symptoms, including postoperative vertigo and oscillopsia due to nystagmus. In general, the dominant symptom postoperatively is vertigo. Preoperative chemical vestibular ablation can reduce vestibular symptoms postoperatively. We used 1.0 mL of 40 mg/mL nonbuffered gentamicin in three intratympanic installations over 2 days, 2 months preoperatively in 10 patients. Reduction of vestibular function was measured by the head impulse test and the caloric test. Reduction of vestibular function was found in all gentamicin patient groups. After gentamicin vestibular ablation, patients underwent home vestibular exercising for two months. The control group consisted of 10 patients who underwent only home vestibular training two months preoperatively. Postoperative rates of recovery and vertigo in both groups were evaluated with the Glasgow Benefit Inventory (GBI), the Glasgow Health Status Inventory (GHSI), and the Dizziness Handicap Inventory questionnaires, as well as survey of visual symptoms by specific questionnaire developed by us. There were no statistically significant differences between both groups with regard to the results of questionnaires. Patients who received preoperative gentamicin were more resilient to optokinetic and optic flow stimulation (p < 0.05). This trial is registered with clinical study registration number NCT02963896.

Strategy for the surgical treatment of vestibular schwannomas in patients with neurofibromatosis type 2

ObjectiveGuidelines for appropriate management of vestibular schwannomas in NF2 patients are controversial. In this paper we reviewed our experience with patients with NF2 for the results of surgical treatment with particular reference to hearing and facial nerve preservation. MethodsWe included in the study 30 patients (16 women and 14 men) with the diagnosis of NF2 treated in our department between 1998 and 2014 who underwent surgery for vestibular schwannoma removal with a follow-up for at least 1 year. In 3 cases, the vestibular schwannomas were unilateral. Six patients with bilateral vestibular schwannomas underwent unilateral procedure. Therefore, 51 acoustic tumors were studied in 30 patients. ResultsNo operative death we noted. Significant deterioration to the non-functional level occurred in 19 out of 22 cases with well-preserved preoperative hearing. Only three ears maintained their preoperative good hearing. Hearing was preserved in cases of small schwannoma not exceeding 2cm. Among 21 patients who underwent bilateral operations hearing was preserved in 3 out of 7 cases when smaller tumor or better hearing level side was attempted at first surgery. In contrary none of the 14 patients retained hearing when the first operation concerned the worse-hearing ear. Among 14 tumors up to 2cm there was only one case of moderately severe facial nerve dysfunction (House–Brackmann Grade IV) in the long follow-up. ConclusionEarly surgical intervention for vestibular schwannoma in NF2 patient is a viable management strategy to maintain hearing function and preserve facial nerve function.

Clinical features of vestibular schwannomas in patients who experience hearing improvement after surgery.

Postoperative improvements in hearing in patients with vestibular schwannoma are extremely rare. We reviewed nine cases retrospectively to investigate the clinical features of these cases. Hearing improvement was defined as an improvement in hearing class according to American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria. The nine patients comprised five men and four women with a mean age of 40.4 years. Of the nine tumors, three were solid and six cystic; mean tumor size was 29.7 mm. Mean pure tone average (PTA) and mean speech discrimination scores (SDS) were 47.5 dB and 22.8%, respectively, preoperatively and 29.6 dB and 83.9%, respectively, postoperatively. AAO-HNS class distribution was class B:1 and D:8, preoperatively, and class A: 5 and B:4, postoperatively. A lateral suboccipital retrosigmoid approach with a lateral (park bench) position was used in all nine patients. Clinical features of these vestibular schwannomas included (1) large cystic tumors, (2) sudden onset hearing loss, (3) the presence of a valley shape in the middle-pitch area on preoperative audiograms, (4) almost intact preoperative inner ear function, (5) a low SDS relative to PTA preoperatively, (6) surgical treatment via a lateral suboccipital approach within 6 months of the most recent exacerbation of hearing loss, (7) observation of I waves in preoperative, intraoperative, and postoperative auditory brainstem response (ABR) recordings, and (8) postoperative improvement in mainly the middle-pitch range and SDS. For surgical treatment of vestibular schwannomas with the above clinical features, a translabyrinthine approach and cochlear nerve section (unless the I wave on the intraoperative ABR trace disappears) should be avoided, regardless of the patient's preoperative hearing level, if a surgeon hopes to maximize the chances of preserving or improving hearing.

A meta-analysis of treatment of vestibular schwannoma using Gamma Knife radiosurgery.

Aim of the studyOne of the alternative methods of surgical treatment of vestibular schwannoma is Gamma Knife radiosurgery. The purpose of this metaanalysis was to analyze the progress in treatment of vestibular schwannoma using Gamma Knife radiosurgery based on data in the literature of the last five years.Material and methodsIn the collected English-language literature from the years 2007–2011, contained in 20 scientific journals, clinical articles of many years study at a single center were extracted and also review papers and case reports. The main criteria of our own analysis were: patient age, tumor size, the dose in Gy, the time from surgery to follow-up, the degree of tumor growth inhibition, and hearing preservation. For statistical calculations comparing series of studies we used nonparametric analysis of variance and tests at the significance level of p > 0.05.ResultsThe 46 evaluated clinical articles show the results of studies over many years. A comparison of the results of the analysis made on the basis of papers published in the period 1998-2007 with the results of the current series from the period 2007–2011 allowed us to establish that the average dose applied to the periphery of the tumor was lower (12.4 Gy) than in the earlier series of 1998–2007 (14.2 Gy), and hearing preservation was higher (66.45% vs. 51.0%).ConclusionsClinical findings widely documented in the literature over the past five years indicate the progress in treatment of vestibular schwannoma using Gamma Knife radiosurgery.

Age, gender and tumour size predict work capacity after surgical treatment of vestibular schwannomas

AimsThe aim of the present study was to identify predictive factors for outcome after surgery of vestibular schwannomas.DesignThis is a retrospective study with partially collected prospective data of patients who...