Vestibular Schwannoma Surgery Research Articles

Rear Admiral (Astronaut) Alan Shepard: Ménière's disease and the race to the moon.

On May 5, 1961, Alan B. Shepard Jr. piloted the Freedom 7 craft into a suborbital flight to become the first American man in space. His promising astronautical career was soon scuttled by spells of dizziness and tinnitus later diagnosed as Ménière's disease, until William F. House-considered the father of neurotology and a pioneer in surgery for vestibular schwannomas-intervened. In 1968 House implanted an endolymphatic-subarachnoid shunt, which at the time was a virtually experimental procedure. Shepard's debilitating Ménière's disease was cured, but not quite in time for him to pilot the doomed Apollo 13 mission; he was reassigned to Apollo 14 and as a result would step foot on the moon on February 5, 1971. This historical vignette depicts the tale of how the career trajectories of Shepard and House-two notable figures in their respective fields-fatefully intersected.

Risk Factors for 30-Day Non-Neurological Morbidity and Cerebrospinal Fluid Leak in Patients Undergoing Surgery for Vestibular Schwannoma.

Introduction We analyzed perioperative risk factors for morbidity and mortality for the patients undergoing surgical intervention for vestibular schwannoma along with rates of cerebrospinal fluid (CSF) leaks that required surgery. Materials and Methods Patients undergoing surgery vestibular schwannoma were identified in the American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2016 using current procedural terminology (CPT) codes for posterior fossa surgical approaches and International Classification of Diseases 9th revision (ICD 9) and ICD 10 codes for peripheral nerve sheath tumor. Preoperative laboratories, comorbidities, and operative times were analyzed along with CSF leaks and unplanned returns to the operating room. Results Nine-hundred ninety-three patients fit the inclusion criteria. Average age was 51, 41% were male, and 58% were female. Mortality within 30 days of the operation was very low at 0.4%, complications were 7% with infection being the most common at 2.3%, and unplanned reoperations happened in 7.4% of the cases. Dependent functional status (odds ratio [OR]: 5.7, 95% confidence interval [CI]: 1.9-16.6, p = 0.001), preoperative anemia (OR: 2.4, 95% CI: 1.2-4.5, p = 0.009), and operative time over 8 hours (OR: 1.9, 95% CI: 1.1-3.4, p = 0.017) were the only significant predictors of perioperative complications. CSF leak postoperatively occurred in 37 patients (3.7%). Reoperation for CSF leak was necessary in 56.3% of the cases. Operative time over 8 hours was the only independent significant predictor of postoperative CSF leak (OR: 2.2, 95% CI: 1.1-4.3, p = 0.028). Conclusion Dependent functional status preoperatively, preoperative anemia, and duration of surgery over 8 hours are the greatest predictors of complications in the 30-day postoperative period.

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.

Extended Retrolabyrinthine Approach: Results of Hearing Preservation Surgery Using a New System for Continuous Near Real-time Neuromonitoring in Patients With Growing Vestibular Schwannomas.

To report hearing preservation results after retrolabyrinthine vestibular schwannoma surgery, using a new system for continuous near real-time monitoring of cochlear nerve function. Retrospective chart review. Tertiary referral center, University Hospital. Thirty-one consecutive patients with growing vestibular schwannomas and opting for hearing preservation surgery. Tumor removal by a modified, extended retrolabyrinthine approach, using a new system for continuous near real-time monitoring of cochlear nerve function. Pure-tone average and speech discrimination (SD) 1-year postoperative. Preservation of word recognition score class. Preservation of serviceable hearing (SD>50%). Any hearing was preserved in 83 and 69% had preserved word recognition score class or better. Serviceable hearing was preserved in 77%. SD was unchanged in 48%, improved in 21%, and poorer in 31%. Of 18 patients with potential for improvement (SD 90% or worse preoperatively), 33% improved (SD increase 10% or more). The hearing preservation rate is favorable using the modified, extended retrolabyrinthine approach and a new system for continuous near real-time monitoring of cochlear nerve function for removal of growing vestibular schwannomas, as 77% preserved serviceable hearing 1 year after surgery. Hearing improved after surgery in 33%. Using the new neuromonitoring system, serviceable hearing preservation rate improved from 53 to 77% at our center.

Microsurgical treatment of cerebrospinal fluid rhinorrhea after operation of vestibular schwannoma due to the opening of internal auditory canal

Objective To investigate the microsurgical treatment of refractory cerebrospinal fluid (CSF) rhinorrhea after operation of vestibular schwannoma due to the opening of internal auditory canal. Methods From January 2012 to May 2018, a total of 249 patients with vestibular schwannoma underwent tumor resection at Neurosurgery Department, Xuanwu Hospital of Capital Medical University. There were 8 (3.2%) cases that developed CSF rhinorrhea after operation. Among them, 5 underwent conservative therapy and CSF leakage disappeared and the remaining 3 (1.2%) cases with refractory CSF leakage received second craniotomy for CSF leakage repair on the 3rd, 9 th and 28 th day after tumor resection respectively. Suboccipital retrosigmoid approach (original incision) was used to repair the defect of posterior wall of internal auditory canal. Fresh muscle granules and glue were used to seal the defect of posterior wall of internal auditory canal. Results Among the 3 patients who underwent surgical repair operation, CSF leakage disappeared immediately in 2 cases and cured one month later in 1 case. Facial nerve function was not affected after the second operation. The assessment based on House-Brackman classification revealed grade 1 in 2 cases and grade 2 in 1 case at discharge. All the 3 patients developed intracranial infection and recovered after anti-infection therapy. Conclusions CSF rhinorrhea after vestibular schwannoma surgery is a relatively common complication. Meticulous sealing of opened air cells in the petrous bone (around the inner auditory canal and mastoid air cells) seems necessary for the prevention and treatment CSF leakage. Key words: Neuroma, acoustic; Cerebrospinal fluid rhinorrhea; Microsurgery; Inner auditory canal

Application of multi-mode intraoperative monitoring of facial nerve structure and function preservation during giant vestibular schwannomas surgery: A retrospective study

Objectives To explore the application value of intraoperative multi-mode facial nerve monitoring during resection of giant vestibular schwannomas and to provide evidence for further technical and surgical refinements. Methods A total of 58 patients with giant vestibular schwannomas (tumor diameter≥3 cm) underwent microsurgical resection at Department of Neurosurgery, the First Affiliated Hospital of Xiamen University and were retrospectively analyzed in this study. From December 2016 to January 2018, 28 cases who received multi-mode intraoperative monitoring were set as monitoring group. From March 2013 to November 2016, 30 cases without multi-mode intraoperative monitoring were set as control group. The baseline data (age, sex, size of tumor, cystic-solid quality of tumor, side of tumor), operational duration, surgical resection rate, anatomical and function preservation (evaluated based on House-Brackmann grade) of facial nerves and postoperative complication were compared between the 2 groups. Results The operational duration was obviously shorter in monitoring group (413.4±166.1 min) with statistical difference (t=-2.02, P=0.048) compared to that in control group (499.7±159.6 min). Total resection rate in monitoring group was 100.0% (28/28) and that in control group was 93.3% (28/30). Anatomical preservation rate in monitoring group was 100.0% (28/28) while that in control group was 90.0% (27/30). There was no significant difference in total resection rate or anatomical preservation rate between the 2 groups(both P>0.05). Significantly higher function preservation rate of facial nerves was observed in monitoring group than in control group at 1 week (P=0.043) and 3 months (P=0.039) post surgery. The incidence rate of complication was lower (P=0.029) in monitoring group (14.3%) than in control group(40.0%). Conclusion Intraoperative multi-mode facial nerve monitoring could help shorten the operation duration, increase the function preservation rate of the facial nerves and reduce the clinical postoperative complications. Key words: Neuroma, acoustic; Neurosurgical procedures; Facial nerve; Intraoperative neurophysiologic monitoring

Protein profiling of cerebrospinal fluid from patients undergoing vestibular schwannoma surgery and clinical significance

Vestibular schwannoma (VS) is a common disease in the region of the cerebellopontine angle in the posterior cranial fossa. Large VS and its surgical management usually lead to severe cranial nerve dysfunction and affect the patient’s quality of life. We aimed to find some possible progression markers of VS. Here, we sought to characterize the cerebrospinal fluid (CSF) proteome of patients with different VS grades and recurrence to identify biomarkers predictive of VS growth or recurrence. CSF was collected intraoperatively prior to removal of untreated VS, including grade I–V and recurrence. Isobaric tags for relative and absolute quantitation–based proteomic analysis of CSF from 43 VS patients and 3 control patients was used to identify candidate proteins. Ninety-three overlapping proteins were found to display differential expression in grade I, II, III, IV, and V VS patients compared with the control group. Nine proteins were chosen for validation with enzyme-linked immunosorbent assay. VS was distinguished from control patients based on the expression patterns of six proteins (ATP-binding cassette subfamily A member 3 [ABCA3], secretogranin-1 [SCG1], Krueppel-like factor 11 [KLF11], voltage-dependent calcium channel subunit alpha-2/delta-1 [CA2D1], brain acid soluble protein 1 [BASP1], and peroxiredoxin-2 [PRDX2]. ABCA3 and KLF11 were positively correlated with the size of early-phase of VS, while BASP1 and PRDX2 showed a negative correlation. ABCA3, CA2D1, and KLF11 were upregulated, while BASP1 and PRDX2 were downregulated in the CSF from VS recurrence. But SCG1 was increased only at early-phase. These data suggest that increased ABCA3 and KLF11 and decreased BASP1 and PRDX2 in CSF are associated with VS growth at the early phase or recurrence.

Vestibular Schwannoma Resection in a Consecutive Series of 502 Cases via the Retrosigmoid Approach: Technical Aspects, Complications, and Functional Outcome

Outcome in vestibular schwannoma (VS) surgery has improved enormously over the last decades. Surgical positioning remains a matter of discussion. A standardized protocol for diagnostics and management has been applied and evaluated for complications and functional outcome. We examined 502 VS tumors in 483 patients (227 men and 256 women) between 2005 and 2016. According to our patient selection and treatment algorithm, 488 operations (97%) were performed in the semi-sitting position, and 14 (3%) were in the supine position. Auditory and facial functions were analyzed before and after surgery as were perioperative complications. There were 182 patients (36%) with small tumors (Hannover classification T1-T3A) and 320 (64%) large tumors (T3B or T4). Of the patients, 14% were neurofibromatosis type 2 cases. Complete tumor resection was achieved in 96.4%. Hearing preservation occurred in 44% of patients with small tumors and 23% of those with large tumors (Hannover classification), and correlated significantly with tumor size (P < 0.001). Facial palsy (House Brackmann grades II-VI) was present in 63 patients before and in 185 patients after surgery. Useful facial function (House Brackmann grades I-III) early after surgery was maintained in 86% of patients with small tumors and in 77% of patients with large tumors. Intraoperative complications included air embolism in 45 cases (9%), sinus injury in 3 cases, cerebrospinal fluid leakage in 46 cases (9%), and local hemorrhage in 19 cases (4%). Surgical revision was indicated in 31 cases (6%). In a standardized setting, the semi-sitting position allowed a safe approach. This setting offers the advantage of bimanual tumor nerve handling by the surgeon and an optimal visualization of important functional structures.

A critical comparison between the semisitting and the supine positioning in vestibular schwannoma surgery: subgroup analysis of a randomized, multicenter trial.

Patient positioning in vestibular schwannoma (VS) surgery is a matter of ongoing discussion. Factors to consider include preservation of cranial nerve functions, extent of tumor resection, and complications. The objective of this study was to determine the optimal patient positioning in VS surgery. A subgroup analysis of a randomized, multicenter trial that investigated the efficacy of prophylactic nimodipine in VS surgery was performed to investigate the impact of positioning (semisitting or supine) on extent of resection, functional outcomes, and complications. The data of 97 patients were collected prospectively. All procedures were performed via a retrosigmoid approach. The semisitting position was chosen in 56 patients, whereas 41 patients were treated while supine. Complete resection was obtained at a higher percentage in the semisitting as compared to the supine position (93% vs 73%, p = 0.002). Logistic regression analysis revealed significantly better facial nerve function in the early postoperative course in the semisitting group (p = 0.004), particularly concerning severe facial nerve paresis (House-Brackmann grade IV or worse; p = 0.002). One year after surgery, facial nerve function recovered. However, there was still a tendency for better facial nerve function in the semisitting group (p = 0.091). There were no significant differences between groups regarding hearing preservation rates. Venous air embolism with the necessity to terminate surgery occurred in 2 patients in the semisitting position (3.6%). Supplementary analysis with a 2-tailed permutation randomization with 10,000 permutations of treatment choice and a propensity score matching showed either a tendency or significant results for better facial nerve outcomes in the early postoperative course and extent of resection in the semisitting group. Although the results of the various statistical analyses are not uniform, the data indicate better results concerning both a higher rate of complete removal (according to the intraoperative impression of the surgeon) and facial nerve function after a semisitting as compared to the supine position. These advantages may justify the potential higher risk for severe complications of the semisitting position in VS surgery. The choice of positioning has to consider all individual patient parameters and risks carefully.

Is endoscopic inspection necessary to detect residual disease in acoustic neuroma surgery?

To analyze how and when the endoscope is used in vestibular schwannoma surgery and identify the benefits of using endoscopy in this type of surgery. It is currently unclear if there is any benefit from using an endoscope in vestibular schwannoma surgery so this retrospective analysis set out to study this. All the patients who underwent vestibular schwannoma surgery at our clinic were included for all the vestibular schwannoma approaches taken. We studied when endoscopy was used during surgery and the goal of using endoscopy. Several pre- and postoperative factors were assessed such as complications, facial function, and hearing function in the case of techniques that allow hearing preservation. From January 2015 to September 2018, 280 patients underwent lateral skull base surgery. Of these, 112 were included in this study. The endoscope was used in all 112 patients, and in eight cases it was possible to identify residual disease using the endoscope to check the surgical field, and then to remove the disease under endoscopic view. Moreover, in two other cases, the endoscope was used to resolve a vasculoneural conflict between the anterior inferior cerebellar artery (AICA) loop and facial nerve in one case, and for deafferentation of the superior and inferior vestibular nerves in the second case. No major intraoperative complications occurred in our series. There was no statistically significant difference in postoperative facial nerve function between patients in whom the endoscope was used as a diagnostic tool and patients in whom it was used as an operative tool (p = 0.3152). The endoscope may be useful, especially in surgical techniques where there is poor control of the internal auditory canal (IAC). An endoscopic support technique is strongly recommended to avoid residual disease, particularly in retrosigmoid and retrolabyrinthine approaches. Moreover, the recent introduction of the transcanal transpromontorial approach allows the endoscope to be used during all the procedures in patients affected by a vestibular schwannoma limited to the IAC or to support surgical procedures during an enlarged microscopic approach.

Retractorless Surgery for Giant Vestibular Schwannomas via the Retrosigmoid Approach

A fixed retractor is routinely used during surgery for vestibular schwannoma to maintain the surgical corridor; however, brain injuries can be caused by use of retractors. The aim of this study was to present strategies for retractorless surgery for giant vestibular schwannomas and compare retractorless surgery with traditional retractor-assisted surgery to illustrate feasibility and potentially superiority of retractorless surgery. Clinical data of 61 patients with giant (≥4 cm diameter) vestibular schwannomas undergoing craniotomy were retrospectively analyzed. Patients were divided into 2 cohorts: 1) 35 patients with traditional retractor surgery performed between June 2016 and July 2017; 2) 26 patients with retractorless surgery performed between June 2016 and July 2018. Duration of operation, intraoperative blood loss, extent of resection, rate of retention of facial nerve function, postoperative brain injury rate, intracranial infection rate, hospitalization time, and grade of facial nerve function were compared between the 2 groups. The incidence of postoperative brain injury was 3.84% in the retractorless surgery group, which was significantly lower compared with the traditional retractor surgery group (22.86%) (P < 0.05). No significant differences were found regarding the other characteristics compared. Through appropriate comprehensive measures, retractorless surgery for giant vestibular schwannomas is an achievable goal. This procedure can reduce the incidence of postoperative brain injury with satisfactory tumor resection.

Predictive Factors of Early Postoperative and Long-Term Facial Nerve Function After Large Vestibular Schwannoma Surgery

The preservation of acceptable facial nerve (FN) function after surgery is the key concern for most patients with vestibular schwannomas (VS). To assess predictive factors of early postoperative and long-term FN function in patients harboring large VS operated with a FN-sparing technique. Single-center retrospective cohort study with 169 consecutive large VS operated on between January 2003 and May 2015. Clinical, radiologic, and intraoperative factors were assessed according to FN function. At last follow-up examination, among the 145 patients without preoperative FN palsy, FN function was good (House-Brackmann [HB] grades I or II) in 84% and moderate (HB grade III) in 15% of patients. Only 1 patient presented with poor HB grade IV function. Multivariate logistic regression model showed the mean preoperative VS extrameatal diameter as being an independent predictor of an unfavorable initial FN outcome (odds ratio [OR], 1.062; P= 0.038). Surgical anatomic preservation of the cochlear nerve was associated with better FN outcomes (OR, 0.237; P= 0.012). A history of previous surgery seemed to be related to long-term impaired FN function (OR, 71.405; P=0.042), as well as early postoperative FN function (OR, 19.068; P= 0.000). No correlation was found between a history of previous Gamma Knife surgery treatment (P=0.225) or the extent of resection (P= 0.438) and impaired FN outcomes. History of previous surgery was identified as an unfavorable predictive recovery factor of impaired postoperative FN function (P= 0.034). As long as the extent of resection or additional Gamma Knife surgery have not been identified as predictive risk factors of postoperative FN palsy, we suggest that optimal resection is the main option for patients harboring large VS.

A-train clusters and the intermedius nerve in vestibular schwannoma patients

ObjectiveEMG “A-train” activity correlates with postoperative facial palsy after vestibular schwannoma (VS) surgery. An intermedius nerve separate from the facial nerve increases A-trains without significant impact on function. We investigate occurrence of A-train “clusters”, A-trains over a majority of channels within a short time frame. MethodsData from 217 patients with first surgery for VS were evaluated retrospectively. Continuous EMG recorded with 9 channels was evaluated for A-train patterns. “Clusters” of A-trains were identified, i.e. A-trains within 3 seconds over a majority of channels. Relation to a separate intermedius, tumor size and facial palsy was evaluated. ResultsCorrelations between A-trains and postoperative facial palsy were higher in patients without separate intermedius (r = 0.562 versus r = 0.194). Clusters were identified in 107 patients (49.3%), separate intermedius in 109 (50.2%), with significant association of both (p < 0.001, Chi-Square test). Excluding clusters slightly increased correlation of A-trains to facial nerve function. ConclusionsA-train clusters have limited relevance for predicting postoperative paresis. However, they should be regarded as warning signs, suggesting the presence of a separate intermedius nerve. SignificanceA-train “clusters” are a sign of hyperactivity of the facial nerve due to a separate intermedius nerve and may confound intraoperative monitoring during VS surgery.

Audiologic prognostic factors for hearing preservation following vestibular schwannoma surgery

Postoperative hearing loss after vestibular schwannoma (VS) removal still remains a lifelong problem for the patients. The present study analyzes the problem of hearing preservation after VS removal from a different angle than available professional literature on this topic. To identify audiologic factors which determine the extent of hearing loss in patients operated on for VS. The study group included 86 patients operated on due to VS accessed via the middle cranial fossa. The analyses involved the effect on absolute hearing loss, which was calculated on the basis of the results of pure-tone audiometry performed preand postoperatively, and factors included in the preoperative audiologic tests, such as pure-tone audiometry, speech audiometry, auditory brainstem response (ABR), and impedance audiometry. The following parameters were demonstrated to have a prognostic value: 1. hearing thresholds at 125 Hz, 500 Hz and 1,000 Hz for the operated ear, Pure Tone Average (PTA) - calculated specifically at 500 Hz, 1,000 Hz and 2,000 Hz and at 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz for the operated ear, and normal audiometric curve; 2. speech discrimination ranging from 55 dB to 75 dB for the operated ear, speech detection threshold (SDT) in the operated ear and interaural difference at 25-35 dB (non-operated vs operated ear); 3. presence of wave V, the values of I-V and III-V intervals for the operated ear, the amplitude of wave V, and the interaural ratio of wave V amplitudes; 4. intensity level for obtaining stapedial reflex or an abnormal reflex at Ipsi 500 Hz, 1,000 Hz and 2,000 Hz, and Contra 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz. The better the preoperative hearing status, the more substantial surgery-related hearing loss was observed. A number of preoperative parameters of the basic diagnostic set of audiologic tests present a prognostic value for the degree of surgery-related hearing loss in VS patients.

Changes in tinnitus after vestibular schwannoma surgery

We designed a prospective study to evaluate changes in tinnitus after vestibular schwannoma (VS) surgery. Subjects included 41 patients who were diagnosed with a VS and underwent translabyrinthine microsurgery (TLM) between January 2015 and May 2016. All patients underwent related examinations and were asked to answer the Tinnitus Handicap Inventory (THI) scale and a visual analog scale (VAS) of tinnitus severity both pre- and postoperatively. Of the 41 patients, 31 (75.6%) suffered from tinnitus before surgery. Microsurgery was associated with an overall decrease in tinnitus (p < 0.001). There was a significant improvement in THI and VAS scores after surgery (p = 0.001 and p = 0.005, respectively). The decrease in THI scores in the low-frequency group was significantly larger than that of the mid- and high-frequency groups after surgery (p = 0.034 and p = 0.001, respectively). The loudness of tinnitus decreased significantly after surgery (p = 0.031). Tinnitus in patients with VS improved after TLM. Patients with mid-/high-frequency tinnitus and louder tinnitus preoperatively seemed to have a worse prognosis than those with low-frequency and quieter tinnitus.

Predictors of central vestibular compensation after surgery for vestibular schwannomas.

SUMMARYSurgical removal of vestibular schwannoma causes acute vestibular symptoms, including postoperative vertigo which is the most negative factor affecting quality of life in patients after vestibular schwannoma surgery. The main aim of this study is to determine whether the results from routine electronystagmography with pathological visually-provoked responses can predict poor postoperative compensation. We also investigate whether postoperative central compensation is related to objective parameters such age, tumour size, length of surgery and persistent nystagmus. According to the results from preoperative electronystagmography, patients were divided into three groups: peripheral, central and combined vestibular syndrome. Signs of central compensation were evaluated by the presence of postoperative nystagmus, vertigo, deviation of subjective visual vertical and head impulse test. There were no statistically significant differences between groups in observed signs of compensation. These results suggest that pathological central oculomotor parameters are not a negative predictive factor for central vestibular compensation.

Short-Term Surgical Outcome for Vestibular Schwannoma in Sweden: A Nation-Wide Registry Study.

Background: Vestibular Schwannoma (VS) is a benign neoplasm arising from the 8th cranial nerve, with surgery one of the treatment modalities. In a nation-wide registry study, we describe the baseline, treatment characteristics, and short-term outcome in patients surgically treated for VS.Methods: We performed a nationwide study with data from the Swedish Brain Tumor Registry (SBTR) for all adults diagnosed with VS 2009–2015. Patient symptoms, tumor characteristics, and postoperative complications were analyzed.Results: In total 348 patients underwent surgery for VS. Mean age was 50.6 ± 14.5 years and 165 patients (47.4%) were female. The most common symptom was focal neurological deficit (92.0%), with only 25 (7.2%) being asymptomatic prior to surgery, and 217 (63.6%) had no restriction in activity. Following surgery, 100 (28.7%) patients developed new deficit(s). In terms of postoperative complications; 11 (3.2%) had a hematoma, 35 (10.1%) an infection, 10 (2.9%) a venous thromboembolism, and 23 (6.6%) had a reoperation due to complication. There were no deaths within 30-days after surgery. When grouped according to tumor size (< 4 vs. ≥4 cm), those with ≥4 cm tumors were more often males (p = 0.02), had more often ICP related symptoms (p = 0.03) and shorter time from imaging to surgery (p < 0.01). Analysis of the younger (< 65 years) vs. elderly (≥65 years) revealed no difference in outcome except increased 1-year mortality (p = 0.002) in elderly.Conclusion: In this nation-wide registry-study, we benchmark the 30-day complication rate after VS surgery as collected by the SBTR. Further, we present the current neurosurgical outcome data from both VS smaller than 40 mm compared to larger tumors, as well as younger vs. elderly VS patients. Since surgical decision making is a careful consideration of short term risk vs. long term benefit, this information can be useful in clinical decision making.

Headache, Cerebrospinal Fluid Leaks, and Pseudomeningoceles after Resection of Vestibular Schwannomas: Efficacy of Venous Sinus Stenting Suggests Cranial Venous Outflow Compromise as a Unifying Pathophysiological Mechanism.

Background Regardless of the operative approach, headache, cerebrospinal fluid (CSF) leaks, and pseudomeningoceles remain disproportionately common problems after surgery for vestibular schwannomas and have a significant negative impact on quality of life and potential to return to full employment. Recent work has raised the possibility that these problems may, in part, be related to acquired obstruction of cranial venous outflow. This article explores this idea further with respect to a group of patients with severe and intractable symptoms. Objective The main objective of this article is to describe our experience diagnosing, investigating, and treating cranial venous outflow obstruction following translabyrinthine resection of vestibular schwannomas. Methods Retrospective review of all patients ( n = 9) at our institution referred for sigmoid sinus stenting following translabyrinthine surgery. Results Headache resolved or improved after sigmoid stenting in all five patients in whom it was the primary symptom. CSF leak was the primary problem in two patients. In one, the leak was unchanged, but headache improved. In the other, the leak resolved, and headache improved. Two patients had symptomatic pseudomeningoceles and both resolved Conclusion Assuming a meticulous approach to wound closure, a CSF leak following surgery for vestibular schwannoma can be viewed as a pathological, but essentially homeostatic, response to raised intracranial pressure caused by acquired obstruction to cranial venous outflow. Postoperative headache (from high or low intracranial pressure) and CSF leaks, therefore, may all respond to measures aimed at eliminating the obstructing lesion.

Hearing Preservation in Vestibular Schwannoma Surgery.

Modern imaging techniques allow early detection of small vestibular schwannomas (VSs) with minimal or no hearing impairment. While controversy surrounds the management of these tumors, given their benign nature and unpredictable natural history, microsurgical excision is the only modality that offers the opportunity to cure the tumor and preserve hearing. Hearing preservation in VS surgery may be accomplished via the middle fossa or retrosigmoid approaches. Appropriate patient selection and surgical approach is critical in achieving the best hearing outcomes. This article highlights the preoperative assessment, patient selection and prognostic factors, intraoperative monitoring of hearing, and surgical approaches to optimize hearing preservation during VS removal.

Effectiveness of preoperative facial nerve diffusion tensor imaging tractography for preservation of facial nerve function in surgery for large vestibular schwannomas: Results of a prospective randomized study.

The goal of surgery in case of a large vestibular schwannoma is complete excision of tumor and preservation of facial nerve function. The identification and preservation of facial nerve is very difficult during surgery, particularly in case of large tumors. This prospective randomized study was conducted to find out the effectiveness of preoperative facial nerve diffusion tensor imaging tractography (DTI) to predict location of the nerve and preservation of facial nerve function in surgery for large vestibular schwannomas. In this prospective randomized study, we recruited 100 patients with a large vestibular schwannoma(> 3cm). After initial scrutiny, 94 patients were randomized based on a computer generated chart. In group I, preoperative DTI was done and the operating surgeon was informed about the position of facial nerve preoperatively. In group II, DTI was not done. The facial nerve preservation rates and clinical outcome at follow up was compared between the two groups. Out of 94 patients, there were 47 patients in group I (DTI group) and 47 patients in group II (Non DTI group). In DTI group, 40 patients were left for comparison after the exclusion criteria was applied. Preoperative DTI predicted that the facial nerve position was concordant with its intraoperative position in 39 patients (97.5% concordance). Facial nerve preservation rates were statistically significant in group I (DTI group) (P value = 0.002). The study establishes the role of preoperative DTI tractography for better facial nerve preservation in surgery for large vestibular schwannomas (>3 cm).