Vestibular Schwannoma Resection Research Articles

Extent of resection and progression-free survival in vestibular schwannoma: a volumetric analysis.

To preserve facial nerve function in vestibular schwannoma (VS) microsurgery, some have advocated subtotal resection (STR) if the tumor is densely adherent to a thinned facial nerve. The objective of this study was to determine if residual volume is associated with progression and whether there is a threshold residual volume that should be pursued during STR to prevent recurrence. A secondary objective of this study was to determine whether facial nerve function at last follow-up was associated with extent of resection (EOR). Clinical and radiographic data were retrospectively collected from the records of 164 patients with VS who underwent resection. Tumor volumes were measured using Visage, and standard statistical methods were used. The House-Brackmann scale was used to assess changes in facial nerve function before surgery and at last follow-up. Sixty-one patients (37%) received gross-total resection (GTR) and 103 (63%) received STR. The median clinical and radiographic follow-ups were 49 and 48 months, respectively. The median residual volume was 0.5 cm3 after STR. Kaplan-Meier actuarial survival analysis revealed a 96.3% 5-year progression-free survival (PFS) rate after GTR, which was greater than that after STR (84.5%, p = 0.03). Recursive partitioning analysis of patients receiving STR revealed a residual volume of 0.60 cm3 as the optimal threshold for recurrence. Patients with residual volume ≥ 0.60 cm3 had a 76.0% 5-year PFS, regardless of adjuvant SRS, which was lower than that for patients undergoing GTR (96.3%) or STR (95.6%) with residual volumes < 0.60 cm3 (p < 0.01). On Cox regression analysis, residual volume ≥ 0.60 cm3 (HR 14.4, p = 0.01) was independently associated with progression, even when accounting for patient age, adjuvant radiosurgery, and preoperative tumor size. In 112 patients with at least 24 months of follow-up after their last treatment, tumor control was achieved in 111 (99.1%) patients at a median last follow-up of 71 months. Worse facial nerve function at the last follow-up was independently associated with prior treatment for VS (adjusted OR 3.7, p = 0.04), but not residual volume cohort or preoperative tumor volume. Residual volume > 0.60 cm3 after VS resection was independently associated with tumor progression, even accounting for adjuvant SRS. These data support maximizing the EOR during VS surgery, even if GTR cannot be safely achieved.

Labyrinthectomy Improves Dizziness in Patients with Vestibular Schwannoma

Abstract Objective Dizziness is one of the most prevalent and debilitating symptoms associated with vestibular schwannoma (VS), and there are little data on contributing or alleviating factors in the perioperative setting. In this study, we aimed to evaluate whether vestibular nerve sectioning or labyrinthectomy concomitant with surgical resection would improve dizziness in the postoperative period. Methods This is a retrospective study of a consecutive series of VS patients who underwent resection at a large tertiary care center between 2009 and 2023. Dizziness at 6 months was the primary endpoint, whereas facial nerve and hearing outcomes were secondary endpoints. Fisher's exact test was used to identify significant differences between categorical variables, and multivariate logistic regression analysis was performed to identify predictors of dizziness as well as facial nerve and hearing outcomes. Results A total of 333 patients underwent resection of VS at our institution. There was no significant difference in binary reported dizziness based on surgical approach (p = 0.14). However, patients reported significantly less dizziness at discharge (p &lt; 0.01) as well as 6-month (p = 0.02) and 1-year (p &lt; 0.01) follow-up in the translabyrinthine group. On the other hand, patients who underwent labyrinth-sparing approaches reported a significant increase in dizziness that remained up to 1 year from the time of surgery. Conclusions Our data suggest that labyrinthectomy may improve dizziness symptoms in patients with VS. Selective VN sectioning does not appear to affect dizziness or hearing outcomes. Finally, surgical approach does not affect facial nerve outcomes.

Subtotal resection of vestibular schwannoma with subsequent Gamma Knife irradiation - tumor growth control, facial and cochlear nerve outcome - preliminary results.

&lt;b&gt;Introduction:&lt;/b&gt; The choice of treatment of vestibular schwannoma (VS) depends on several factors, including the tumor size, the patient's age and overall health, and the presence and severity of symptoms.&lt;b&gt;Aim:&lt;/b&gt; The aim of the study was to assess the effectiveness of intentional subtotal resection (STR) of tumor followed by Gamma Knife surgery (GKS) in patients with larger VS (Koos 3 and 4).&lt;b&gt;Materials and methods:&lt;/b&gt; The retrospective analysis was performed on 18 patients. Data of VS volumes measured in MRI, the facial nerve function assessed in the House-Brackmann scoring system (HB), and the results of audiological examination expressed on the Gardner-Robertson scale (GR) were collected preoperatively, postoperatively, and post-GKS.&lt;b&gt;Results:&lt;/b&gt; Preoperatively, the main symptom was hearing loss observed in 13 out of 18 patients. The facial nerve function was assessed as HB 1 in 16, whereas HB 2 in 2 patients. The mean volume of the tumor in the initial MRI amounted to 16.81 cm&lt;sup&gt;3&lt;/sup&gt; . Postoperatively, the facial nerve was assessed as HB 1 or 2 in 16, whereas HB 3 in 2 patients. Serviceable hearing was presented by only 4 persons. The Mean diameter of the tumor after subtotal surgery amounted to 3.16 cm&lt;sup&gt;3&lt;/sup&gt; , 1.83 cm&lt;sup&gt;3&lt;/sup&gt; after GKS, and 1.58 cm&lt;sup&gt;3&lt;/sup&gt; at the last follow-up. The facial nerve function and hearing level remained the same as before GKS in all patients.&lt;b&gt;Conclusions:&lt;/b&gt; STR followed by GKS can be a safe and effective method of treatment of large VS concerning the functional outcome of the facial nerve and the tumor volume growth control.

Ultrasound-guided lesser occipital nerve combined with great auricular nerve block for vestibular schwannoma craniotomy via a suboccipital retrosigmoid approach: a prospective, double-blind randomized controlled trial

PurposeThis aim of this study was to investigate the analgesic efficacy and safety of lesser occipital nerve combined with great auricular nerve block (LOGAB) for craniotomy via a suboccipital retrosigmoid approach.MethodsPatients underwent vestibular schwannoma resection via a suboccipital retrosigmoid approach were randomly assigned to receive ultrasound-guided unilateral LOGAB with 5 ml of 0.5% ropivacaine (LOGAB group) or normal saline (NSB group). Numeric rating scale (NRS) scores at rest and motion were recorded within 48 h after surgery. Mean arterial pressure (MAP), heart rate (HR), opioid consumption and other variables were measured secondly.ResultsAmong 59 patients who were randomized, 30 patients received ropivacaine, and 29 patients received saline. NRS scores at rest (1.8 ± 0.5 vs. 3.2 ± 0.8, P = 0.002) and at motion (2.2 ± 0.7 vs. 3.2 ± 0.6, P = 0.013) of LOGAB group were lower than those of NSB group within 48 h after surgery. NRS scores of motion were comparable except for 6th and 12th hour (P < 0.05) in the LOGAB group. In LOGAB group, MAP decreased significantly during incision of skin and dura (P < 0.05) and intraoperative opoid consumption was remarkably reduced (P < 0.01). Postoperative remedial analgesia was earlier in the NSB group (P < 0.001). No patients reported any adverse events.ConclusionAmong patients undergoing craniotomy for vestibular schwannoma via a suboccipital retrosigmoid approach, LOGAB may be a promising treatment for perioperative analgesia and has the potential to maintain intraoperative hemodynamic stability.Clinical trial registration numberChictr.org.cn ChiCTR2000038798.

Intraoperative Hearing Monitoring Using ABR and TT-ECochG and Hearing Preservation during Vestibular Schwannoma Resection.

Background: Quick and appropriate diagnostics and the use of intraoperative monitoring (IM) of hearing during vestibular schwannoma (VS) resection increase the likelihood of hearing preservation. During surgery, various methods of IM can be used, i.e., auditory brainstem responses (ABRs), transtympanic electrocochleography (TT-ECochG), and direct cochlear nerve action potentials. The aim of the study was to evaluate the prognostic values of IM of hearing using ABR and TT-ECochG in predicting postoperative hearing preservation and to evaluate relationships between them during various stages of surgery. Methods: This retrospective study presents the pre- and postoperative audiological test results and IM of hearing records (TT-ECochG and ABR) in 75 (43 women, 32 men, aged 18-69) patients with diagnosed VS. Results: The preoperative pure tone average hearing threshold was 25.02 dB HL, while after VS resection, it worsened on average by 30.03 dB HL. According to the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) Hearing Classification, before and after (pre/post) surgery, there were 47/24 patients in hearing class A, 9/8 in B, 2/1 in C, and 17/42 in D. In speech audiometry, the average preoperative speech discrimination score at an intensity of 60 dB SPL was 70.93%, and after VS resection, it worsened to 38.93%. The analysis of electrophysiological tests showed that before the tumor removal the I-V ABR interlatencies was 5.06 ms, and after VS resection, it was 6.43 ms. Conclusions: The study revealed correlations between worse postoperative hearing and changes in intraoperatively measured ABR and TT-ECochG. IM of hearing is very useful in predicting postoperative hearing in VS patients and increases the chance of postoperative hearing preservation in these patients.

Factors Affecting Speech Discrimination After Vestibular Schwannoma Resection.

Investigate the relationship between word recognition score (WRS) and pure tone average (PTA) after hearing preservation surgery for vestibular schwannomas (VS) as well as evaluate the consistency of hearing classification systems. A retrospective chart review was performed. This study included patients from a single academic tertiary referral hospital. Patients with VS and serviceable hearing who underwent hearing preservation surgery 2014-2023. Patients excluded for neurofibromatosis 2 and lacking pre/postop audiograms. All patients underwent resection of vestibular schwannoma. Pre/postop WRS, PTA, and AAO-HNS, Gardner-Robertson (GR), and WRS Class (WRSC) hearing classifications. Seventy-five patients were included. Average preop and postop PTA and WRS were 26 ± 12 dB, 79 ± 39 dB, 92 ± 12%, and 33 ± 43%, respectively. Postop PTAs were distributed along the complete testable decibel range, while the postop WRS displayed a bimodal distribution, with WRS >50% or <20%. Worsening intraop ABR changes were significantly associated with poorer hearing outcomes (p = 0.005). With increasing Koos grades, intraop ABRs were significantly more likely to exhibit changes (p = 0.005). AAO-HNS and GR classified patients nearly identically, while the WRSC resulted in more class I and fewer class II. The cutoff of serviceable hearing was comparable across all classification systems. Effects on the brainstem component of Koos 3-4 tumors may particularly disturb speech processing. This effect seems amplified by surgical dissection. AAO-HNS, GR, and WRSC hearing classifications are comparable in describing serviceable hearing in vestibular schwannoma patients.

Endoscopic-Assisted Presigmoid Approach to the Internal Auditory Canal. A Feasibility Study.

The retrolabyrinthine (presigmoid) approach has been utilized in various skull base surgeries but has not been fully utilized in the management of internal auditory canal (IAC) lesions, such as vestibular schwannoma (VS). Microsurgical retrolabyrinthine approach provides limited visualization of the IAC, while endoscopic-assisted techniques allow for further lateral exposure with labyrinthine preservation. Traditional approaches to the IAC have the disadvantage of hearing sacrifice or retraction of brain tissue. With the introduction of endoscopic techniques and enhanced visualization, access to this region of complex anatomy is possible. Radiomorphometric and anatomical dissection was performed on two cadaveric temporal bones. High-resolution computed tomography was used to segment and delineate the volume of the IAC. Projected accessible IAC was compared to actual postdissection data with preservation of the posterior semicircular canal (PSCC) via the retrolabyrinthine corridor. While preserving the PSCC, the 0° and 30° endoscopes visualized 57.1% and 78.6% of the IAC for cadaver 1, and 64.0% and 76.0% of the IAC for cadaver 2, respectively. Sacrificing the PSCC, the 0° and 30° endoscopes provided visualization of 78.6% 85.7% of the IAC for cadaver 1, and 88.0% and 95.1% of the IAC for cadaver 2, respectively. Retrolabyrinthine approach to resection of VS is a potentially viable hearing-preserving alternative to traditional approaches. This approach provides access to the majority of the IAC, while angled endoscopes or sacrifice of the PSCC can provide additional access toward the fundus. Further studies are needed to determine the clinical feasibility of this approach.

Mapping the clinical pathway for patients undergoing vestibular schwannoma resection

The introduction of electronic health records (EHR) has improved the collection and storage of patient information, enhancing clinical communication and academia. However, EHRs remain limited by data quality and the time-consuming task of manual data extraction. This study aims to utilise process mapping to help identify critical data entry points within the clinical pathway for VS patients, ideal for structured data entry and automated data collection, in an effort to improve patient care and research. A two-stage methodology was conducted at a neurosurgical unit. Process maps were developed using semi-structured interviews with stakeholders in the management of VS resection. Process maps were then retrospectively validated against EHR for patients admitted between August 2019 and December 2021, establishing critical data entry points. Twenty stakeholders were interviewed in the process map development. Process maps were validated against the EHR of 36 patients admitted for VS resection. Operation notes, surgical inpatient reviews (including ward rounds) and discharge summaries were present for all patients, representing critical data entry points. Areas for documentation improvement were present in the preoperative clinics (30/36, 83.3%), preoperative skull base multidisciplinary team (32/36, 88.9%), postoperative follow-up clinics (32/36, 88.9%), and the postoperative skull base multidisciplinary team meeting (29/36, 80.6%). This is a first use of a two-stage methodology for process mapping the clinical pathway for patients undergoing VS resection. Our study identified critical data entry points which can be targeted for structured data entry and for automated data collection tools, positively impacting patient care and research.

Vestibular Schwannomas: implementation of PANQOL and Mayo VSQOL Index scales in Ukraine and justification of treatment strategy with preservation of quality of life (problem analysis, own experience, discussion points)

Objective: To evaluate the treatment outcomes of sporadic vestibular schwannomas (VS) to substantiate the choice of optimal treatment strategy considering quality of life indicators using the Penn Acoustic Neuroma Quality of Life Scale (PANQOL) and the Mayo Clinic Vestibular Schwannoma Quality of Life Index (Mayo VSQOL Index) scales in Ukraine. Materials and Methods: 1100 patients with VS were treated at the Subtentorial Neurooncology Department from 2001 to October 2023 and 373 were primarily considered for dynamic observation (“wait-and-scan”) at the Department of Ear Microsurgery and Otoneurosurgery of the Kolomiichenko Otolaryngology Institute. Data on 359 patients (some of whom underwent surgery in the mentioned departments) who received radiotherapy (RT) from 2010 to 2023 in the Radioneurosurgery Department are also provided. The PANQOL and Mayo VSQOL Index scales were implemented to assess the quality of life of patients with VS. Scientific publications from the PubMed database related to the study of the quality of life in patients with VS were analyzed. Results: The analysis was based on patient data from the database for the period 2017 - October 2023, 391 patients with VS were treated, including 359 who underwent surgical treatment (schwannomas resection), 4 – tarsorrhaphy after VS resection, and 28 who received combined treatment (surgery + radiotherapy). A separate group consisted of 359 patients who underwent radiotherapy (RT). Of 177 patients who underwent radiosurgical treatment, 65 (36.7%) had Stage III VS according to the classification of W.T. Koos, and 112 (63.3%) had stage IV VS. Primarily diagnosed tumors were treated in 110 (62.1%) and 67(37.9%) patients with residual postoperative. Follow-up data were obtained for 159 patients. At the Kolomiichenko Otolaryngology Institute, 373 patients were under observation with the primary "wait-and-scan" strategy, of whom 110 (29.5%) had their VS removed due to symptom progression or progressive course, and 24 (6.4%) underwent RT. Of the 27 patients in the Subtentorial Neurooncology Department study group, 7 (25.9%) underwent surgery, and 5 (18.5%) underwent RT. Conclusions: Global practice in assisting patients with VS indicates a shift towards dynamic follow-up and an increase in the frequency of using radiation treatment methods. Over the past years, strategy have been proposed that do not recommend the "wait-and-scan" mode due to the risk of life-threatening complications associated with tumor growth. However, there is very little data on long-term outcomes (more than 5 years) and quality of life. VS primarily detected by magnetic resonance imaging in Ukraine significantly larger (Koos III-IV) than those reported in the literature. The implementation of specialized scales for assessing the quality of life of VS patients in Ukraine will help improve outcomes by applying personalized criteria for treatment routes, increasing the level of awareness and responsibility of both patients and doctors.

Tumor biomechanical stiffness by magnetic resonance elastography predicts surgical outcomes and identifies biomarkers in vestibular schwannoma and meningioma

Variations in the biomechanical stiffness of brain tumors can not only influence the difficulty of surgical resection but also impact postoperative outcomes. In a prospective, single-blinded study, we utilize pre-operative magnetic resonance elastography (MRE) to predict the stiffness of intracranial tumors intraoperatively and assess the impact of increased tumor stiffness on clinical outcomes following microsurgical resection of vestibular schwannomas (VS) and meningiomas. MRE measurements significantly correlated with intraoperative tumor stiffness and baseline hearing status of VS patients. Additionally, MRE stiffness was elevated in patients that underwent sub-total tumor resection compared to gross total resection and those with worse postoperative facial nerve function. Furthermore, we identify tumor microenvironment biomarkers of increased stiffness, including αSMA + myogenic fibroblasts, CD163 + macrophages, and HABP (hyaluronic acid binding protein). In a human VS cell line, a dose-dependent upregulation of HAS1-3, enzymes responsible for hyaluronan synthesis, was observed following stimulation with TNFα, a proinflammatory cytokine present in VS. Taken together, MRE is an accurate, non-invasive predictor of tumor stiffness in VS and meningiomas. VS with increased stiffness portends worse preoperative hearing and poorer postoperative outcomes. Moreover, inflammation-mediated hyaluronan deposition may lead to increased stiffness.

Preoperative diffusion tensor imaging: Fiber-trajectory-distribution-based tractography to identify facial nerve in vestibular schwannoma.

Tractography of the facial nerve based on diffusion MRI is instrumental before surgery for the resection of vestibular schwannoma, but no excellent methods usable for the suppression of motion and image noise have been proposed. The aim of this study was to effectively suppress noise and provide accurate facial nerve reconstruction by extend a fiber trajectory distribution function based on the fourth-order streamline differential equations. Preoperative MRI from 33 patients with vestibular schwannoma who underwent surgical resection were utilized in this study. First, T1WI and T2WI were used to obtain mask images and regions of interest. Second, probabilistic tractography was employed to obtain the fibers representing the approximate facial nerve pathway, and these fibers were subsequently translated into orientation information for each voxel. Last, the voxel orientation information and the peaks of the fiber orientation distribution were combined to generate a fiber trajectory distribution function, which was used to parameterize the anatomical information. The parameters were determined by minimizing the cost between the trajectory of fibers and the estimated directions. Qualitative and visual analyses were used to compare facial nerve reconstruction with intraoperative recordings. Compared with other methods (SD_Stream, iFOD1, iFOD2, unscented Kalman filter, parallel transport tractography), the fiber-trajectory-distribution-based tractography provided the most accurate facial nerve reconstructions. The fiber-trajectory-distribution-based tractography can effectively suppress the effect of noise. It is a more valuable aid for surgeons before vestibular schwannoma resection, which may ultimately improve the postsurgical patient's outcome.

A multi-institutional machine learning algorithm for prognosticating facial nerve injury following microsurgical resection of vestibular schwannoma

Vestibular schwannomas (VS) are the most common tumor of the skull base with available treatment options that carry a risk of iatrogenic injury to the facial nerve, which can significantly impact patients’ quality of life. As facial nerve outcomes remain challenging to prognosticate, we endeavored to utilize machine learning to decipher predictive factors relevant to facial nerve outcomes following microsurgical resection of VS. A database of patient-, tumor- and surgery-specific features was constructed via retrospective chart review of 242 consecutive patients who underwent microsurgical resection of VS over a 7-year study period. This database was then used to train non-linear supervised machine learning classifiers to predict facial nerve preservation, defined as House-Brackmann (HB) I vs. facial nerve injury, defined as HB II–VI, as determined at 6-month outpatient follow-up. A random forest algorithm demonstrated 90.5% accuracy, 90% sensitivity and 90% specificity in facial nerve injury prognostication. A random variable (rv) was generated by randomly sampling a Gaussian distribution and used as a benchmark to compare the predictiveness of other features. This analysis revealed age, body mass index (BMI), case length and the tumor dimension representing tumor growth towards the brainstem as prognosticators of facial nerve injury. When validated via prospective assessment of facial nerve injury risk, this model demonstrated 84% accuracy. Here, we describe the development of a machine learning algorithm to predict the likelihood of facial nerve injury following microsurgical resection of VS. In addition to serving as a clinically applicable tool, this highlights the potential of machine learning to reveal non-linear relationships between variables which may have clinical value in prognostication of outcomes for high-risk surgical procedures.

A nomogram to predict long-term facial nerve function after vestibular schwannoma resection: a contemporary multi-institutional study

OBJECTIVE The objective of this study was to develop a nomogram to predict long-term facial nerve (FN) function after vestibular schwannoma (VS) resection. METHODS A retrospective cohort study of two tertiary academic skull base referral centers was performed. Consecutive adults &gt; 18 years of age with sporadic unilateral VS who underwent resection between September 2016 and May 2021 were included. FN function in the immediate postoperative period and at the most recent evaluation was measured. RESULTS A total of 306 patients (mean age 49 years, 63% female) were included, with a mean follow-up of 18 months. The mean maximum tumor diameter was 19 mm (range 1–50 mm), and 80 (26.1%) tumors were &gt; 25 mm. Overall, 85% of patients showed good immediate postoperative FN function (House-Brackmann [HB] grade I or II) and 89% maintained good FN function at &gt; 12 months of follow-up. An intraoperative FN electromyographic (EMG) response ≥ 100 µV to 0.05 mA of stimulation (OR 18.6, p &lt; 0.001) was the strongest predictor of good HB grade in the immediate postoperative period. EMG response ≥ 100 µV (OR 5.70, p &lt; 0.001), tumor size ≤ 25 mm (OR 3.09, p &lt; 0.05), and better immediate postoperative HB grade (OR 1.48, p = 0.005) predicted good long-term FN function on multivariable analysis. A point-of-care nomogram based on these data predicted long-term FN function with a sensitivity of 89% and specificity of 69%. CONCLUSIONS Better immediate postoperative HB grade, intraoperative FN EMG response ≥ 100 µV, and tumor size ≤ 25 mm strongly predicted good long-term FN function after VS resection. A point-of-care nomogram based on these variables could serve as a useful tool for postoperative counseling and prognosis of long-term FN recovery.

Hearing preservation outcomes using direct cranial nerve eight and auditory brainstem response neuromonitoring in the resection of vestibular schwannomas

OBJECTIVE Advancements in microsurgical technique and technology continue to improve outcomes in patients with skull base tumor. The primary cranial nerve eight monitoring systems used in hearing preservation surgery for vestibular schwannomas (VSs) are direct cranial nerve eight monitoring (DCNEM) and auditory brainstem response (ABR), although current guidelines are unable to definitively recommend one over the other due to limited literature on the topic. Thus, further research is needed to determine the utility of DCNEM and ABR. The authors performed a retrospective cohort study and created an interactive model that compares hearing preservation outcomes based on tumor size in patients receiving ABR+DCNEM and ABR-only monitoring. METHODS Twenty-eight patients received ABR+DCNEM and 72 patients received ABR-only monitoring during VS hearing preservation surgery at a single tertiary academic medical center between January 2008 and November 2022. Inclusion criteria consisted of adult patients with a preoperative American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) hearing classification of A or B. Tumor size was measured as the maximal medial to lateral length, including the internal auditory canal component. RESULTS Overall hearing preservation (word recognition score [WRS] &gt; 0%) was achieved in 31 patients with ABR-only monitoring (43.1%) and in 18 patients with ABR+DCNEM (64.3%). Serviceable hearing preservation (AAO-HNS class A or B) was attained in 19 patients with ABR-only monitoring (26.4%) and in 11 patients with ABR+DCNEM (39.3%). There was no difference in overall hearing preservation between the two groups (p = 0.13). Change in tumor size was not associated with the odds of serviceable hearing preservation for the ABR-only group (p = 0.89); however, for ABR+DCNEM, there was some indication of an interaction between tumor size and the association of ABR+DCNEM versus ABR-only monitoring, with the odds of serviceable hearing preservation at p = 0.089. Furthermore, with ABR+DCNEM, every 0.5-cm increase in tumor size was associated with a decreased odds of serviceable hearing preservation on multivariable analysis (p = 0.05). For both overall and serviceable hearing preservation, a worse preoperative AAO-HNS classification was associated with a decreased odds of preservation (OR 0.43, 95% CI 0.19–0.97, p = 0.042; OR 0.17, 95% CI 0.053–0.55, p = 0.0031, respectively). CONCLUSIONS The result of this interactive model study proposes that there may be a higher chance of hearing preservation when using ABR+DCNEM rather than ABR alone for smaller tumors, with that relationship reversing as tumor size increases.

Outcomes of Near-Total and Subtotal Resection of Sporadic Vestibular Schwannoma: A Systematic Review and Meta-Analysis.

To evaluate tumor control and facial nerve outcomes after gross-total (GTR), near-total (NTR), and subtotal resection (STR) of sporadic vestibular schwannomas (VS). PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched in August 2021 through inception following PRISMA guidelines. English language articles reporting tumor control and facial nerve outcomes of adults (≥18 years) with NTR and STR of VS were evaluated. Study characteristics, demographics data, tumor characteristics, type of surgical intervention, and outcome measures on tumor control and facial nerve function were collected. Pooled relative risk (RR) estimates for tumor recurrence and facial nerve outcomes were calculated and stratified by extent of resection. From an initial search of 2504 articles, 48 studies were included in the analysis. When comparing 1108 patients who underwent NTR to 3349 patients with GTR, the pooled RR of recurrence in the NTR cohort was 2.94 (95% confidence interval [CI] 1.65-5.24, P = .0002). When comparing 1016 patients who underwent STR to 6171 patients with GTR, the pooled RR of recurrence in the STR cohort was 11.50 (95% CI 6.64-19.92, P < .0001). Estimates for risk of tumor regrowth for less-than-complete resection are presented. There was no elevated risk of adverse facial nerve outcome (defined as House-Brackmann grade III and above) in each category of extent of resection compared to GTR. Extent of resection predicts risk of tumor recurrence/regrowth following microsurgical resection. Favorable facial nerve outcome should be weighed against the increased risk of regrowth and the potential need for further treatment.

P.083 Use of jugular venous pressure to optimize outcomes of vestibular schwannoma resection: a review of the literature and proof of concept

Background: Surgical resection of vestibular schwannoma (VS) is often curative if gross total resection is achieved, however, it is a delicate procedure with high risk to the facial nerve. With retrosigmoid approach for resection, the head is positioned to maximize lateral head rotation and neck flexion in order to optimize the surgical field. However, this may inadvertently occlude cerebral venous drainage, elevating intracranial pressure (ICP) and increasing intraoperative bleeding. Methods: Here, we review relevant literature regarding the effects of head rotation and neck flexion on internal jugular vein (IJV) occlusion and ICP, and highlight the notion that head rotation and flexion may occlude the ipsilateral IJV, increasing ICP. Subsequently, we propose a novel technique using continuous, real-time monitoring of jugular bulb pressure (JBP) to detect obstructions in jugular venous flow and guide optimal head positioning prior to VS resection. Results: As proof of concept, we present a case in which JBP monitoring was employed to optimize head positioning prior to a VS resection, which shows a significant reduction in JBP compared to traditional positioning. Conclusions: This innovative approach offers promise in enhancing the safety and efficacy of intracranial surgery for VS and potentially other neurosurgical procedures.

Vestibular Schwannoma and Tinnitus: A Systematic Review of Microsurgery Compared to Gamma Knife Radiosurgery.

Background: Vestibular schwannoma (VS) is a benign tumor of the eighth cranial nerve formed from neoplastic Schwann cells. Although VS can cause a variety of symptoms, tinnitus is one of the most distressing symptoms for patients and can greatly impact quality of life. The objective of this systematic review is to comprehensively examine and compare the outcomes related to tinnitus in patients undergoing treatment for VS. Specifically, it evaluates patient experiences with tinnitus following the removal of VS using the various surgical approaches of traditional surgical resection and gamma knife radiosurgery (GKS). By delving into various aspects such as the severity of tinnitus post-treatment, the duration of symptom relief, patient quality of life, new onset of tinnitus after VS treatment, and any potential complications or side effects, this review aims to provide a detailed analysis of VS treatment on tinnitus outcomes. Methods: Following PRISMA guidelines, articles were included from PubMed, Science Direct, Scopus, and EMBASE. Quality assessment and risk of bias analysis were performed using a ROBINS-I tool. Results: Although VS-associated tinnitus is variable in its intensity and persistence post-resection, there was a trend towards a decreased tinnitus burden in patients. Irrespective of the surgical approach or the treatment with GKS, there were cases of persistent or worsened tinnitus within the studied cohorts. Conclusion: The findings of this systematic review highlight the complex relationship between VS resection and tinnitus outcomes. These findings underscore the need for individualized patient counseling and tailored treatment approaches in managing VS-associated tinnitus. The findings of this systematic review may help in guiding clinicians towards making more informed and personalized healthcare decisions. Further studies must be completed to fill gaps in the current literature.

Use of jugular venous pressure to optimize outcomes of vestibular schwannoma resection: a review of the literature and proof of concept

Background: Surgical resection of vestibular schwannoma (VS) and other benign posterior fossa tumors is often curative if gross total resection is achieved, however, these lesions pose unique challenges due to their intricate location and proximity to critical structures. Approaches for resection often utilize lateral head rotation and neck flexion in order to optimize the surgical field. However, this may inadvertently occlude cerebral venous drainage, elevating intracranial pressure (ICP) and increasing intraoperative bleeding, potentially increasing the operative risk to patients. Methods: We review relevant literature regarding the effects of head rotation and neck flexion on internal jugular vein (IJV) occlusion and ICP, and highlight the notion that head rotation and flexion may occlude the ipsilateral IJV, increasing ICP. Subsequently, we propose a novel technique using continuous, real-time monitoring of jugular bulb pressure (JBP) to detect obstructions in jugular venous flow and guide optimal head positioning prior to VS resection. Results: As proof of concept, we present a single-patient case in which JBP monitoring was employed to optimize head positioning prior to a VS resection, which shows a significant reduction in JBP compared to traditional positioning. Conclusion: This innovative approach offers promise in enhancing the safety and efficacy of intracranial surgery for VS and other neurosurgical procedures.

Concept Recognition and Characterization of Patients Undergoing Resection of Vestibular Schwannoma Using Natural Language Processing

Abstract Background Natural language processing (NLP), a subset of artificial intelligence (AI), aims to decipher unstructured human language. This study showcases NLP's application in surgical health care, focusing on vestibular schwannoma (VS). By employing an NLP platform, we identify prevalent text concepts in VS patients' electronic health care records (EHRs), creating concept panels covering symptomatology, comorbidities, and management. Through a case study, we illustrate NLP's potential in predicting postoperative cerebrospinal fluid (CSF) leaks. Methods An NLP model analyzed EHRs of surgically managed VS patients from 2008 to 2018 in a single center. The model underwent unsupervised (trained on one million documents from EHR) and supervised (300 documents annotated in duplicate) learning phases, extracting text concepts and generating concept panels related to symptoms, comorbidities, and management. Statistical analysis correlated concept occurrences with postoperative complications, notably CSF leaks. Results Analysis included 292 patients' records, yielding 6,901 unique concepts and 360,929 occurrences. Concept panels highlighted key associations with postoperative CSF leaks, including “antibiotics,” “sepsis,” and “intensive care unit admission.” The NLP model demonstrated high accuracy (precision 0.92, recall 0.96, macro F1 0.93). Conclusion Our NLP model effectively extracted concepts from VS patients' EHRs, facilitating personalized concept panels with diverse applications. NLP shows promise in surgical settings, aiding in early diagnosis, complication prediction, and patient care. Further validation of NLP's predictive capabilities is warranted.

Recovery of turning speed in patients after vestibular schwannoma resection.

Individuals after a vestibular schwannoma resection (VSR) experience significant vestibular symptoms that can be provoked with turning. Vestibular rehabilitation assists in recovery of function and symptom relief, however turning response is unknown. Examine peak turning speed response to surgery and rehabilitation. Eight participants with a vestibular schwannoma (PwVS) and five healthy controls (HC) participated in this study. Peak turning speed (PTS) was captured with inertial measurement units (IMU) at the head and/or trunk during turning tasks at a pre-operative, post-operative and post-treatment assessment. Vestibular rehabilitation was provided twice weekly for six weeks. Linear mixed models were used to assess change in PTS across time points. PwVS performed slower PTS than HC prior to surgery. PTS was significantly slower post-operatively compared to pre-operative during walking with head turns (B = -61.03, p = 0.004), two-minute walk test (B = -37.33, p = 0.015), 360° turn (B range from 50.05 to -57.4, p < 0.05) and complex turning course (CTC) at the trunk (B = -18.63, p = 0.009). Post-treatment PTS was significantly faster than pre-operative during CTC at the head (B = 18.46, p = 0.014) and trunk (B = 15.99, p = 0.023). PwVS may have turning deficits prior to surgical resection. PTS was significantly affected post-operatively, however improved with rehabilitation.