Surgical Removal Of Vestibular Schwannoma Research Articles

Proteomic Shotgun and Targeted Mass Spectrometric Datasets of Cerebrospinal Fluid (Liquor) Derived from Patients with Vestibular Schwannoma

Vestibular schwannomas are relatively rare intracranial tumors compared to other brain tumors. Data on the molecular features, especially on schwannoma proteome, are scarce. The 41 cerebrospinal fluid (liquor) samples were obtained during the surgical removal of vestibular schwannoma. Obtained peptide samples were analyzed by shotgun LC-MS/MS high-resolution mass spectrometry. The same peptide samples were spiked with 148 stable isotopically labeled peptide standards (SIS) followed by alkaline fractionation and scheduled multiple reaction monitoring (MRM) for quantitative analysis. The natural counterparts of SIS peptides were mapped onto 111 proteins that were Food and Drug Administration (FDA)-approved for diagnostic use. As a result, 525 proteins were identified by shotgun LC-MS/MS with high confidence (at least two peptides per protein, FDR < 1%) in liquor samples. Absolute quantitative concentrations were obtained for 54 FDA-approved proteins detected in at least five experimental samples. Since there is lack of data on the molecular landscape of vestibular schwannoma, the obtained datasets are unique and one of the first in its field.

Feasibility of Preoperative Video Head Impulse Test to Predict the Nerve of Origin in Patients with Vestibular Schwannomas.

Vestibular schwannoma (VS) originates from Schwann cells in the superior or inferior vestibular nerve. Identifying the precise origin will help in determining the optimal surgical approach. We retrospectively analyzed the preoperative vestibular function test according to VS origin to determine whether the test is a valuable indicator of tumor origin. Forty-seven patients with VS (male:female = 18:29, mean age: 54.06 ± 13.50 years) underwent the cochleovestibular function test (pure-tone audiometry, caloric test, video head impulse test (vHIT), cervical and ocular vestibular-evoked myogenic potential, and posturography). All patients then underwent surgical removal of VS, and the schwannoma origin was confirmed. The tumor originated from the superior vestibular nerve (SVN group) in 21 patients, the inferior vestibular nerve (IVN group) in 26 patients, and an undetermined site in eight patients. The only value that differed significantly among the groups was the gain of the vestibular-ocular reflex (VOR) in the ipsilesional posterior canal (iPC) during the vHIT. Our results indicate that VOR gain in the iPC may be used to predict the nerve origin in patients with VS. Other cochleovestibular function tests have limited value to discriminate nerve origins, especially in cases of medium to large VS.

Change in Tinnitus After Acoustic Neuroma Removal Using a Translabyrinthine Approach. A Prospective Study

IntroductionTinnitus is one of the primary symptoms of vestibular schwannoma (VS) and the effect of surgery is unpredictable. Materials and methodsWe conducted a prospective study of the patients who underwent a translabyrinthine approach for the treatment of their VS (2009–2013) at our Hospital. Patients answered the Tinnitus Handicap Inventory (THI) questionnaire pre- and postoperatively. The clinical charts provided data such as age, gender, tumour size, preoperative audiometry and postoperative facial function. ResultsThe study included 39 patients. Of these, 71.8% suffered from tinnitus: 50% grade I, 17.9% grade II, 10.7% grade III, 21.4% grade IV and 0% grade V. We found no statistical association between tinnitus and the different variables measured preoperatively. Postoperatively, 48.7% of the patients suffered from tinnitus: 31.6% grade I, 36.8% grade II, 10.5% grade III, 15.8% grade IV and 5.3% grade V. The difference between mean pre- and postoperative THI was statistically significant (P=.011); this difference was greater in younger patients. We have found a significant negative correlation (r=−0.335; P=.037) between preoperative audiometry and postoperative THI. ConclusionsWe did not find any significant association between tinnitus and age, gender, tumour size and postoperative facial function. Translabyrinthine surgical removal of VS in these patients led to better THI results, with the younger patients having better outcomes. The patients with poorest preoperative audition were the ones that had the best results in the postoperative THI questionnaire.

Marked Hearing Improvement After Surgical Removal of Vestibular Schwannoma With Profound Hearing Loss

Marked Hearing Improvement After Surgical Removal of Vestibular Schwannoma With Profound Hearing Loss

Estudio prospectivo de la evolución del acúfeno tras exéresis por vía translaberíntica del neurinoma del acústico

IntroductionTinnitus is one of the primary symptoms of vestibular schwannoma (VS) and the effect of surgery is unpredictable. Materials and methodsWe conducted a prospective study of the patients who underwent a translabyrinthine approach for the treatment of their VS (2009-2013) at our Hospital. Patients answered the Tinnitus Handicap Inventory (THI) questionnaire pre- and postoperatively. The clinical charts provided data such as age, gender, tumour size, preoperative audiometry and postoperative facial function. ResultsThe study included 39 patients. Of these, 71.8% suffered from tinnitus: 50% grade I, 17.9% grade II, 10.7% grade III, 21.4% grade IV and 0% grade V. We found no statistical association between tinnitus and the different variables measured preoperatively. Postoperatively, 48.7% of the patients suffered from tinnitus: 31.6% grade I, 36.8% grade II, 10.5% grade III, 15.8% grade IV and 5.3% grade V. The difference between mean pre- and postoperative THI was statistically significant (P=.011); this difference was greater in younger patients. We have found a significant negative correlation (r=–0.335; P=.037) between preoperative audiometry and postoperative THI. ConclusionsWe did not find any significant association between tinnitus and age, gender, tumour size and postoperative facial function. Translabyrinthine surgical removal of VS in these patients led to better THI results, with the younger patients having better outcomes. The patients with poorest preoperative audition were the ones that had the best results in the postoperative THI questionnaire.

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.

Near total extirpation of vestibular schwannoma with salvage radiosurgery.

The management of a sporadic vestibular schwannoma (VS) has changed with the introduction of stereotactic radiosurgery (SRS). Because functional outcome is important, particularly regarding the facial nerve, a policy of near-total surgical resection of a large-size VS has emerged, minimizing damage to the facial nerve. The debate remains whether the surgical remnant should be treated immediately or after established growth. Retrospective case series. A consecutive cohort of 55 patients underwent a retrosigmoid craniotomy and near-total removal of a large-size VS at our university medical center between 2005 and 2011 and had a follow-up of a least 3 years. Documented growth of the VS remnant after surgery necessitating adjuvant SRS was the primary outcome measure using analysis of variance. In 45 patients (81.8%), a small tumor remnant was left during surgery. The mean preoperative tumor volume was 12.2 cm(3) (range, 1.13-50.16 cm(3)); the mean volume of the remnant was 0.22 cm(3) (range, 0-1.52 cm(3)). The mean postoperative follow-up time was 35.4 months (range, 3-76 months). Salvage SRS was deemed necessary in seven patients (13.0%). The size of the postoperative tumor remnant was a significant predictor for the necessity of postoperative adjuvant SRS. Normal facial nerve function (House-Brackmann [HB] I) was preserved in 30 patients (57.7%), 17 patients (32.7%) experienced a permanent mild facial nerve deficit (HB II, III), and five patients (9.6%) experienced a severe facial nerve deficit (HB grade IV-VI). Initial observation after near total surgical removal of VS is a feasible strategy, with only a minority requiring salvage radiosurgery during follow-up.

Surgery for auditory brainstem implantation

Patients with neurofibromatosis 2 present complex and challenging management dilemmas. Surgical removal of vestibular schwannomas often results in total hearing loss. Early diagnosis using gadolinium-enhanced magnetic resonance imaging and refinements in hearing preservation surgery have improved our ability to prevent total hearing loss while achieving complete removal in smaller tumors, but for patients with larger tumors or for those with no useful hearing in that ear, the auditory brainstem implant (ABI) allows restoration of some auditory function when the tumor is removed. Additionally, children with cochlear aplasia and cochlear nerve deficiency have begun to be implanted with ABIs, with varied results. This article discusses surgical placement of the ABI.

How to Eradicate CSF Leak in the Postoperative Course of Vestibular Schwannoma, Exclusively Using Transpetrosal Approaches

Objective: To report eradication of postoperative meningitis and cerebrospinal fluid (CSF) leak after vestibular schwannoma (VS) surgery. Methods: We analyzed a series of 400 consecutive patients who underwent surgical removal of VS via transpetrosal approaches (translabyrinthine approach [TLA] or widened retrolabyrinthine approaches [WRLA]). At the time of closing the surgical approach, all opened mastoid air cells surrounding the internal auditory meatus were filled with bone wax. In WRLA, the middle ear was preserved and the aditus blocked by a single thick piece of bone wax. In TLA, the eustachian tube was tightly closed through the epitympanum with several small pieces of the same material after incus removal. In both, fibrin glue was used to stabilize the fat graft and prevent CSF leakage. This graft consisted of two separate pieces of fat and secured with glue, before wound closure. Results: There were 191 men and 209 women. Mean age was 51.9 years (range, 11-80 years). Tumor size was Koos stage 1 in 35 cases, stage 2 in 128 cases, stage 3 in 84 cases, and stage 4 in 153. TLA was used in 281 patients and WRLA in 119 cases. Mortality was absent. No patient had a CSF fistula. Only one case of meningitis was observed, following a wound abscess. Conclusion: We have observed that postoperative complications related to the CSF fistulas were not a fatality and could be avoided in transpetrosal approaches with a very simple but cautions technique of closure.

A Case of Marked Hearing Improvement after Surgical Removal of Vestibular Schwannoma with Profound Hearing Loss

21세 여자 환자가 내원 1년 전부터 점차 심해지는 보행장애 와 조음장애를 주소로 본원 신경과를 내원하였다. 3년 전부 터 우측 청력도 서서히 저하되어 이에 대한 평가를 위해 이비 인후과로 의뢰되었다. 1년 전 이명이 일시적으로 있었으나 내 원 당시에는 없었으며 두통을 호소하고 어지럼증은 자세불 안정의 형태를 보였다. 이학적 검사상 양측 고막은 정상 소견 을 보였으며, 고실도 검사상 양쪽 모두 A형으로 정상이었다. 순음청력검사상 좌측은 정상 청력역치를 나타내었으나 우측 은 전농 소견을 보였다(Fig. 1A). 병변측의 일과성 유발이음 A Case of Marked Hearing Improvement after Surgical Removal of Vestibular Schwannoma with Profound Hearing Loss

Vestibular compensation after vestibular schwannoma surgery: normalization of the subjective visual vertical and disability

Conclusions: The degree of caloric weakness before surgery influences faster or slower recovery of patients undergoing vestibular schwannoma surgery. The Dizziness Handicap Inventory (DHI) is a good index to show the recovery of patients as it relates directly to an improvement or not of the subjective visual vertical (SVV). Objective: To evaluate the process of recovery of patients as measured by the SVV and the DHI after surgical removal of vestibular schwannoma. Methods: We studied 24 consecutive patients of the University Hospital of Salamanca who underwent vestibular schwannoma surgery. We assessed age, tumour size, degree of canalicular weakness and preoperative SVV, and their relationship with DHI and SVV at discharge and also at 1, 3 and 6 months postoperatively. Results: Patients with lesser degrees of caloric weakness took longer to normalize SVV than those with a higher caloric weakness before surgery (p < 0.05). There was a significant correlation between DHI and improvements in SVV with time. The differences disappeared in 6 months where all patients, with greater or lesser degree of caloric weakness, had the same results.

Diffusion Tensor Tractography of the Facial Nerve

Objective: 1) Demonstrate that preoperative diffusion tensor (DT) tractography can predict the displacement of the facial nerve in the vicinity of vestibular schwannomas. 2) Demonstrate that the course of the constructed tract consistently agreed with the surgical findings in most of the cases. Method: Prospective study of 15 patients undergoing surgical removal of vestibular schwannomas. The course of the facial nerve, determined preoperatively by diffusion tensor tractography using the method of Taoka et al was compared with the course of the nerve determined intraoperatively by microscopic inspection and using facial nerve monitoring equipment. Results: The displaced facial nerve was identified in 14 patients by diffusion tensor tractography in axial and coronal T1 post-gadolinium and equivalent tractography images. In 13 patients there was a precise correspondence between the course of the nerve determined preoperatively by diffusion tensor tractography and the course of the nerve found at surgery. In 1 patient the facial nerve was found anterior/cranial to the tumor while tractography seemed to depict an anterior/caudal course. Conclusion: Diffusion tension tractography of the facial nerve is a feasible technique that can consistently predict the displacement of the facial nerve in the vicinity of vestibular schwannomas. The technique can be used preoperatively to lower the risk of facial nerve injury during acoustic neuroma surgery.

How obliteration of petrosal air cells by vestibular schwannoma influences the risk of postoperative CSF fistula

Introduction For postoperative CSF-fistula prevention a better understanding of its origins and risk factors is necessary. To identify the role of the tumor growth for the risk to develop CSF-fistula we performed a retrospective analysis. Methods 519 patients between the years 2000 and 2007 had a retrosigmoidal surgical removal of vestibular schwannoma in a standardized procedure. 22 CSF-fistula-patients were chosen for evaluation. 78 patients were randomly selected as control group in four equally sized cohorts: male/female with small/large tumors. Preoperative CT-scans were analyzed regarding IAC-length, diameter of the IAC porus (IAP), tumor size and pneumatization of the posterior wall (PW) of the IAC. Results The mean length of the IAC was 1.2 cm, SD 0.17. There was a significant difference between the diameter of the IAP in cases of small tumors and those of large tumors. Patients with small tumors also showed a larger fraction with visible pneumatization of the PW (34.88%) in the CT-scan than patients with large tumors (24.07%). There is a positive correlation between tumor grade and diameter of the IAP. At the same time there is an inverse correlation between tumor grade and pneumatization of the PW. Conclusions Widening of the IAC by tumor growth may leads to obliteration of air cells in the PW and therefore can be protective concerning CSF-fistula. At the same time patients with small tumors and a visible pneumatization in the PW must be expected to have a higher risk of CSF-fistula.

CONSERVATIVE OR SURGICAL TREATMENT OF A VESTIBULAR SCHWANNOMA

To the Editor: In the recent publication of Malhotra et al. "Clinical, radiographic, and audiometric predictors in conservative management of vestibular schwannoma" (1), we have noticed 2 flaws. In their article, which we read with interest, the conservative management of 202 patients with a vestibular schwannoma is discussed, and univariate and multivariate analyses were performed. We subscribe the need and use of a wait-and-scan policy in vestibular schwannomas because their tendency for growth and complications is on average low. Our main remark is regarding their discussion. Regarding radiotherapy and surgical treatment of vestibular schwannomas, they are stating that "these treatments carry nonnegligible consequences in terms of morbidity, mortality and quality of life." For mortality and facial nerve preservation, the risk is quoted and referred to recent articles. However, cerebrospinal fluid (CSF) leakage is quoted as approximately 15% with no reference. This is a wrong presumption and, without reference, not a sustainable figure. We have studied our result for many years with one of the largest series of surgical removal of vestibular schwannomas with a CSF leak rate of 0 and 1.4% (2,3). Even when not quoting the least amount of CSF rate reported in literature (2,3), a recent review has calculated an overall rate of 9.5% (4). We think that CSF leak in vestibular schwannoma surgery can be reduced to an absolute minimum with the use of the right surgical procedure (5). Malhotra et al. is furthermore stating in their introduction that "the present article describes the largest single-institution series of VS patients followed by conservative management," whereas for many years, the ENT Department of the Gentofte University Hospital in Copenhagen, Denmark, has the largest series. They even quote and refer (ref. [29]) to this series of 552 patients in their own article (6). Paul Merkus, M.D., Ph.D. Mario Sanna, M.D. Department of Otology and Skull Base Surgery Grupo Otologico Piacenza, Italy

Acoustic neuroma (vestibular schwannoma): surgical results on 240 patients operated on dorsal decubitus position

To evaluate the result of the surgical treatment of vestibular schwannoma (VS) operated in dorsal decubitus (mastoid position). 240 patients with a VS underwent a retrosigmoid craniotomy for tumor resection in dorsal decubitus (mastoid position). The function of 7th and 8th cranial nerves was monitored during surgery and the opened internal auditory canal (IAC) was reconstructed using a vascularized dura flap, muscle and fibrin glue. Complete tumor removal was achieved in 99% of the cases, with a mortality of 1.6%. The facial nerve function was preserved in 85% of cases and hearing in 40% of the patients (with preoperative hearing) with tumors of up 1.5 cm in diameter. The incidence of cerebrospinal fluid leak was 5.8% and meningitis 2.9%. Venous air embolism was registered in 3% of cases; it was not associated to mortality. Surgical removal of VS in dorsal position has several advantages; the morbidity and mortality are very low.

How to Avoid CSF Leak or Meningitis in the Postoperative Course of Vestibular Schwannoma: Our Experience of 345 Cases over 6 Years

Purpose: To report eradication of postoperative meningitis and CSF leak after vestibular schwannoma (VS) surgery and understand why and how it is possible to avoid such complications. Methods: A retrospective review in a tertiary referral center. We analyzed a series of 350 consecutive patients who underwent surgical removal of VS from 1999 to 2006 via transpetrosal approaches (translabyrinthine approach (TLA) or widened retrolabyrinthine approaches (WRLA)). At the time of closing the surgical approach, all opened mastoid air cells were filled with bone wax, with particular attention to those surrounding the internal auditory meatus. In WRLA, the middle ear was preserved and the aditus blocked by a single thick piece of pericranium, harvested before drilling. In TLA, the eustachian tube was tightly closed through the epitympanum with several small pieces of the same material after incus removal. In both, fibrin glue was used to stabilize the fat graft and prevent CSF leakage. This graft consisted of two separate pieces of fat. The first one was inserted between the posterior dura and the otic capsule (WRLA) or the rest of the labyrinth (TLA). The second one, which was larger, was installed to fill up the remaining bone defect and was secured with glue before wound closure. Antibioprophylaxis with cefazolin was systematically used. No lumbar drainage was used. Results: There were 169 men and 176 women. Mean age was 51.9 years (11 to 80 yrs). Tumor size was Koos stage 1 in 28 cases, stage 2 in 107 cases, stage 3 in 80 cases, and stage 4 in 130. TLA was used in 221 patients and WRLA in 124 cases. Mortality was absent. No patient had a CSF fistula. No meningitis was observed. Conclusion: Postoperative complications due to CSF fistulas may be avoided in transpetrosal approaches with a very simple but cautious closure technique.

Balance, mobility and gaze stability deficits remain following surgical removal of vestibular schwannoma (acoustic neuroma): An observational study

Are there residual deficits in balance, mobility, and gaze stability after surgical removal of vestibular schwannoma? Observational study. Twelve people with a mean age of 52 years who had undergone surgical removal of vestibular schwannoma at least three months previously and had not undergone vestibular rehabilitation. Twelve age- and gender-matched healthy people who acted as controls. Handicap due to dizziness, balance, mobility, and gaze stability was measured. Handicap due to dizziness was moderate for the clinical group. They swayed significantly more than the controls in comfortable stance: firm surface eyes open and visual conflict (p < 0.05); foam surface eyes closed (p < 0.05) and visual conflict (p < 0.05); and feet together: firm surface, eyes closed (p < 0.05), foam surface, eyes open (p < 0.05) and eyes closed (p < 0.01). They displayed a higher rate of failure for timed stance and gaze stability (p < 0.05) than the controls. Step Test (p < 0.01), Tandem Walk Test (p < 0.05) and Dynamic Gait Index (p < 0.01) scores were also significantly reduced compared with controls. There was a significant correlation between handicap due to dizziness and the inability to maintain balance in single limb and tandem stance (r = 0.68, p = 0.02) and the ability to maintain gaze stability during passive head movement (r = 0.78; p = 0.02). A prospective study is required to evaluate vestibular rehabilitation to ameliorate dizziness and to improve balance, mobility, and gaze stability for this clinical group.

Vestibular schwannoma surgery outcomes: our multidisciplinary experience in 400 cases over 17 years.

The aim of the study was to evaluate the incidence of short- and intermediate-term postoperative complications after vestibular schwannoma surgery. Retrospective review in a tertiary referral center. In 400 patients who underwent surgical removal of vestibular schwannoma from 1984 to 2000,symptoms, preoperative evaluation, surgery, and postoperative complications were analyzed using standardized grading systems. One hundred ninety-four men and 206 women had an operation. Mean age was 53.9 years (age range, 11-78 y). Tumor size according to Koos stage was stage 1 in 39 cases, stage 2 in 122 cases, stage 3 in 87 cases, and stage 4 in 152 cases. Preoperatively, 7.5% of patients had facial nerve dysfunction. Surgical approaches were translabyrinthine in 229 patients, widened retrolabyrinthine in 128 cases, suboccipital in 42 cases, and transotic in 1 case. Mortality was 0.5%. Facial nerve was transected in 15 cases (3.7%) and immediately repaired in 5 cases. A delayed hypoglossal-to-facial nerve anastomosis was performed in 12 cases. At 1 year, House-Brackmann grade in 70.7% of patients was 1 to 2; in 24.3%, 3 to 4; and in 5%, 5 to 6. Poor facial nerve outcome was correlated with tumor size, preoperative irradiation, and nerve dysfunction and was not correlated with the approach used. Most patients had postoperative dizziness, and 30% still had vestibular disturbances after 1 year. Nine patients (2.2%) had a cerebrospinal fluid rhinorrhea, and 24 had a cerebrospinal fluid wound leak (6%). Twenty-two patients (5.5%) had postoperative meningitis. Two patients had a cerebellopontine angle hemorrhage, and three a brainstem infarct. Transpetrosal approaches (translabyrinthine, widened retrolabyrinthine) are safe for vestibular schwannoma removal, and rates of postoperative complications and sequelae are decreasing.

Neurofibromatosis 2 in the pediatric population.

Neurofibromatosis 2 is a severe autosomal dominant disorder characterized by the occurrence of bilateral vestibular schwannomas and other benign tumors of the nervous system. Excellent natural history studies exist for adults with neurofibromatosis 2, but limited outcome data are available for children with neurofibromatosis 2. In this study, we present clinical data on 12 patients with neurofibromatosis 2 and age at diagnosis before 18 years. Full record review included surgical reports, pathology reports, and imaging studies; all patients were personally examined by a single author. One third of the patients presented with hearing impairment and another third presented with other cranial nerve dysfunction. Tumor load was extensive, including cranial meningiomas in 75%, cranial schwannomas other than vestibular schwannomas in 83%, and spinal cord tumors in 75%. Family history was present in two thirds of the patients. Surgical removal of vestibular schwannomas was performed in 58%; none had full preservation of hearing postsurgery. Functionally, 75% of children had hearing loss, 83% had visual impairment, 25% had abnormal ambulation, and 25% were performing below grade level. In conclusion, increased clinical awareness, better imaging techniques, and molecular diagnostics have made pediatric diagnosis of neurofibromatosis 2 feasible, but outcomes appear to be worse than in adult patients. Further work is needed to determine optimal management of pediatric neurofibromatosis 2.