Retrosigmoid Approach for Resection of Large Cystic Vestibular Schwannoma

Objectives This video was aimed to describe the surgical indications, relevant anatomy, and surgical steps of retrosigmoid approach for resection of a large cystic vestibular schwannoma (VS). Design The operative steps are described in a surgical instructional video. Setting The surgery took place at a tertiary skull base referral center. Participant Patient is a 62-year-old man who reported with right sided profound hearing loss with no word recognition, progressive dizziness and tinnitus, excruciating burning pain in the V2 distribution of right trigeminal nerve, wide-based gait, and a right cerebellopontine angle (CPA) cystic VS measuring 3.3 cm. Main Outcome Measures The large cystic VS was resected through retrosigmoid approach. Results The surgery resulted in removal of the large cystic VS with initial delayed facial weakness that completely resolved (House Brackmann grade 1) by 3 month follow-up. The patient had no other postoperative complications and is convalescing well from the procedure. Conclusion Cystic VS presents some unique challenges compared with their solid counterparts. The cystic tumor capsule may be very adherent to the adjacent structures, and distinguishing thin cyst walls from the arachnoid of the CPA, can be quite challenging. The retrosigmoid approach provides adequate surgical exposure for VS tumor resection.The link to the video can be found at: https://youtu.be/sFNvRWG465Q.

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Microsurgery for vestibular schwannoma after Gamma Knife surgery: challenges and treatment strategies

Journal of Neurosurgery ◽

10.3171/2014.8.gks141312 ◽

2014 ◽

Vol 121 (Suppl_2) ◽

pp. 150-159 ◽

Cited By ~ 10

Author(s):

Cheng-Chia Lee ◽

Hsiu-Mei Wu ◽

Wen-Yuh Chung ◽

Ching-Jen Chen ◽

David Hung-Chi Pan ◽

...

Keyword(s):

Gamma Knife ◽

Vestibular Schwannoma ◽

Radiation Effects ◽

Tumor Resection ◽

Treatment Strategies ◽

Gamma Knife Surgery ◽

Neurological Outcomes ◽

Radiological Changes ◽

Cyst Development

ObjectResection of vestibular schwannoma (VS) after Gamma Knife surgery (GKS) is infrequently performed. The goals of this study were to analyze and discuss the neurological outcomes and technical challenges of VS resection and to explore strategies for treating tumors that progress after GKS.MethodsIn total, 708 patients with VS underwent GKS between 1993 and 2012 at Taipei Veterans General Hospital. The post-GKS clinical courses, neurological presentations, and radiological changes in these patients were analyzed. Six hundred patients with imaging follow-up of at least 1 year after GKS treatment were included in this study.ResultsThirteen patients (2.2%) underwent microsurgery on average 36.8 months (range 3–107 months) after GKS. The indications for the surgery included symptomatic adverse radiation effects (in 4 patients), tumor progression (in 6), and cyst development (in 3). No morbidity or death as a result of the surgery was observed. At the last follow-up evaluation, all patients, except 1 patient with a malignant tumor, had stable or near-normal facial function.ConclusionsFor the few VS cases that require resection after radiosurgery, maximal tumor resection can be achieved with modern skull-based techniques and refined neuromonitoring without affecting facial nerve function.

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Headache after Removal of Vestibular Schwannoma Via the Retrosigmoid Approach: A Long-Term Follow-Up-Study

Otolaryngology ◽

10.1067/mhn.2003.104 ◽

2003 ◽

Vol 128 (3) ◽

pp. 387-395 ◽

Cited By ~ 88

Author(s):

Bernhard Schaller ◽

Ariane Baumann

Keyword(s):

Fibrin Glue ◽

Aseptic Meningitis ◽

Vestibular Schwannoma ◽

Internal Auditory Canal ◽

Retrosigmoid Approach ◽

Bone Flap ◽

Posterior Aspect ◽

Dural Closure ◽

Postoperative Headache

OBJECTIVE: Our goal was to study the occurrence and source of origin of postcraniotomy headache syndrome after removal of vestibular schwannoma via the retrosigmoid approach. METHODS: A retrospective chart analysis was conducted of all patients with headache at 3 months after removal of vestibular schwannoma from January 1981 through March 1997 and with a minimum of 24 months of follow-up. Diagnosis was made according to the headache classification and was graded using the HARNER scale. Recovery outcome was compared in selected groups of patients with and without headache. A descriptive statistical analysis was used to analyze differences between groups. RESULTS: Of the patients who underwent retrosigmoid craniotomy for removal of vestibular schwannomas, 52 of 155 patients (34%) reported having severe headache of requiring medication every day and/or feeling incapacitated 3 months after surgery. Headache was more prevalent in those who had the bone flap replaced (94% versus 27%), if there was duraplastic or direct dura closure (0% versus 100%). Laboratory-proven aseptic meningitis, most likely due to the use of fibrin glue and drilling of posterior aspect of the internal auditory canal, was mainly associated with postoperative headache (81% versus 2%). In 75% of these cases, calcifications along the brainstem had been noted. CONCLUSION: The origin of postoperative headaches after retrosigmoid vestibular schwannoma resections is not yet fully understood. Different factors may play a role in preventing or reducing headache: dural adhesions to nuchal muscles or to subcutaneous tissues and dural tension in the case of direct dural closure may explain postoperative headache from dural tension. Intradural drilling and the use of fibrin glue may be the source of aseptic meningitis as the etiology of persistent postoperative headache. Prevention of postoperative headache may include the replacement of bone flap at the end of surgery, duraplastic instead of direct dural closure, and prevention of the use of fibrin glue or extensive drilling of the posterior aspect of internal auditory canal.

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Contemporary Surgical Management of Vestibular Schwannomas: Analysis of Complications and Lessons Learned Over the Past Decade

Operative Neurosurgery ◽

10.1227/neu.0b013e3182752b05 ◽

2012 ◽

Vol 72 (2) ◽

pp. ons103-ons115 ◽

Cited By ~ 11

Author(s):

Yoichi Nonaka ◽

Takanori Fukushima ◽

Kentaro Watanabe ◽

Allan H. Friedman ◽

John H. Sampson ◽

...

Keyword(s):

Vestibular Schwannoma ◽

Clinical Status ◽

Neurological Complication ◽

Tumor Resection ◽

Hearing Preservation ◽

Lessons Learned ◽

Vestibular Schwannomas ◽

Consecutive Series ◽

Lower Cranial Nerve

Abstract BACKGROUND: Despite advanced microsurgical techniques, more refined instrumentation, and expert team management, there is still a significant incidence of complications in vestibular schwannoma surgery. OBJECTIVE: To analyze complications from the microsurgical treatment of vestibular schwannoma by an expert surgical team and to propose strategies for minimizing such complications. METHODS: Surgical outcomes and complications were evaluated in a consecutive series of 410 unilateral vestibular schwannomas treated from 2000 to 2009. Clinical status and complications were assessed postoperatively (within 7 days) and at the time of follow-up (range, 1–116 months; mean, 32.7 months). RESULTS: Follow-up data were available for 357 of the 410 patients (87.1%). Microsurgical tumor resection was performed through a retrosigmoid approach in 70.7% of cases. Thirty-three patients (8%) had intrameatal tumors and 204 (49.8%) had tumors that were <20 mm. Gross total resection was performed in 306 patients (74.6%). Hearing preservation surgery was attempted in 170 patients with tumors <20 mm, and good hearing was preserved in 74.1%. The main neurological complication was facial palsy (House-Brackmann grade III-VI), observed in 14% of patients (56 cases) postoperatively; however, 59% of them improved during the follow-up period. Other neurological complications were disequilibrium in 6.3%, facial numbness in 2.2%, and lower cranial nerve deficit in 0.5%. Nonneurological complications included cerebrospinal fluid leaks in 7.6%, wound infection in 2.2%, and meningitis in 1.7%. CONCLUSION: Many of these complications are avoidable through further refinement of operative technique, and strategies for avoiding complications are proposed.

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Retrosigmoid Approach for Resection of Medium-Sized Vestibular Schwannoma

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0039-1677848 ◽

2019 ◽

Vol 80 (S 03) ◽

pp. S284-S284

Author(s):

Michael J. Link ◽

Colin L. W. Driscoll ◽

Yening Feng ◽

Maria Peris-Celda ◽

Christopher S. Graffeo

Keyword(s):

Vestibular Schwannoma ◽

Internal Auditory Canal ◽

Retrosigmoid Approach ◽

Gross Total Resection ◽

Instructional Video ◽

Hearing Level ◽

Facial Nerve Function ◽

Total Resection ◽

Pure Tone Average ◽

Petrous Temporal Bone

Objectives This video was aimed to describe the relevant anatomy and key surgical steps of retrosigmoid approach for gross total resection of a medium-sized vestibular schwannoma (VS). Design The procedure is described in a surgical instructional video. Setting The surgery took place at a tertiary skull base referral center. Participant Patient is a 63-year-old woman who reported with nonserviceable hearing (Pure Tone Average 60 dB Hearing level, Word Recognition Score 45%), occasional tinnitus, and a VS in the left cerebellopontine angle (CPA), extending into internal auditory canal (IAC), measuring 1.7 cm parallel to the petrous temporal bone. Main Outcome Measures The VS was resected by retrosigmoid approach. Results The surgery results gross total resection of the VS with postoperative House–Brackmann grade 1 facial nerve function and no postoperative complications. Conclusion The retrosigmoid approach is a good strategy to remove VS involving the CPA and the IAC.The link to the video can be found at: https://youtu.be/B6K_UkrKitg.

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Facial Nerve Outcomes After Vestibular Schwannoma Microsurgical Resection in Neurofibromatosis Type 2

Otolaryngology ◽

10.1177/0194599820954144 ◽

2020 ◽

pp. 019459982095414

Author(s):

Catherine Sobieski ◽

Daniel E. Killeen ◽

Samuel L. Barnett ◽

Bruce E. Mickey ◽

Jacob B. Hunter ◽

...

Keyword(s):

Facial Nerve ◽

Vestibular Schwannoma ◽

Tumor Volume ◽

Tumor Resection ◽

Neurofibromatosis Type ◽

Neurofibromatosis Type 2 ◽

Tumor Diameter ◽

Microsurgical Resection

Objective The aim of this study is to investigate facial nerve outcomes after microsurgical resection in neurofibromatosis type 2 (NF2) compared to sporadic tumors. Study Design Single institutional retrospective chart review. Setting Tertiary referral center. Methods All adult patients with NF2 vestibular schwannoma (VS) or sporadic VS who underwent microsurgical resection from 2008 to 2019 with preoperative magnetic resonance imaging (MRI) and 1 year of postsurgical follow-up were included. The primary outcome measure was postoperative House-Brackmann (HB) facial nerve score measured at first postoperative visit and after at least 10 months. Results In total, 161 sporadic VSs and 14 NF2 VSs met inclusion criteria. Both median tumor diameter (NF2, 33.5 mm vs sporadic, 24 mm, P = .0011) and median tumor volume (NF2, 12.4 cm3 vs sporadic, 2.9 cm3, P = .0005) were significantly greater in patients with NF2. The median follow-up was 24.9 months (range, 12-130.1). Median facial nerve function after 1 year for patients with NF2 was HB 3 (range, 1-6) compared to HB 1 (range, 1-6) for sporadic VS ( P = .001). With multivariate logistic regression, NF2 tumors (odds ratio [OR] = 13.9, P = .001) and tumor volume ≥3 cm3 (OR = 3.6, P = .025) were significantly associated with HB ≥3 when controlling for age, sex, extent of tumor resection, translabyrinthine approach, and prior radiation. Conclusion Tumor volume >3 cm3 and NF2 tumors are associated with poorer facial nerve outcomes 1 year following microsurgical resection.

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Microsurgical Treatment and Follow-Up of KOOS Grade IV Vestibular Schwannoma: Therapeutic Concept and Future Perspective

Frontiers in Oncology ◽

10.3389/fonc.2020.605137 ◽

2020 ◽

Vol 10 ◽

Author(s):

Sae-Yeon Won ◽

Andreas Kilian ◽

Daniel Dubinski ◽

Florian Gessler ◽

Nazife Dinc ◽

...

Keyword(s):

Tumor Progression ◽

Vestibular Schwannoma ◽

Tumor Resection ◽

Residual Tumor ◽

High Rate ◽

Future Perspective ◽

Nerve Function ◽

Repeat Surgery ◽

Therapeutic Concept

PurposeSurgery of KOOS IV vestibular schwannoma remains challenging regarding the balance of extent of tumor resection (EoR) and functional outcome. Our aim was to evaluate the outcome of surgical resection and define a cut-off value for safe resection with low risk for tumor regrowth of KOOS IV vestibular schwannoma.MethodsAll patients presenting at the authors’ institution between 2000 and 2019 with surgically treated KOOS IV vestibular schwannoma were included. Outcome measures included EoR, facial/hearing nerve function, surgical complications and progression of residual tumor during the median follow-up period of 28 months.ResultsIn 58 patients, mean tumor volume was 17.1 ± 9.2 cm3, and mean EoR of 81.6 ± 16.8% could be achieved. Fifty-one patients were available for the follow-up analysis. Growth of residual tumor was observed in 11 patients (21.6%) followed by adjuvant treatment with stereotactic radiosurgery or repeat surgery in 15 patients (29.4%). Overall serviceable hearing preservation was achieved in 38 patients (74.5%) and good facial outcome at discharge was observed in 66.7% of patients, significantly increasing to 82.4% at follow-up. Independent predictors for residual tumor growth was EoR ≤ 87% (OR11.1) with a higher EoR being associated with a very low number of residual tumor progression amounting to 7.1% at follow-up (p=0.008).ConclusionsSubtotal tumor resection is a good therapeutic concept in patients with KOOS IV vestibular schwannoma resulting in a high rate of good hearing and facial nerve function and a very low rate of subsequent tumor progression. The goal of surgery should be to achieve more than 87% of tumor resection to keep residual tumor progression low.

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Chances of Improvement in Cases of Vestibular Schwannoma Presenting with Facial Nerve Weakness: Presentation of Two Cases and Literature Review

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0038-1661414 ◽

2018 ◽

Vol 80 (01) ◽

pp. 040-045

Author(s):

Ahmed Rizk ◽

Marcus Mehlitz ◽

Martin Bettag

Keyword(s):

Hearing Loss ◽

Facial Nerve ◽

Male Patient ◽

Vestibular Schwannoma ◽

Internal Auditory Canal ◽

Retrosigmoid Approach ◽

Neurophysiological Monitoring ◽

Facial Weakness ◽

First Case ◽

The Brain

Background and Study Aim Facial nerve (FN) weakness as a presenting feature in vestibular schwannoma (VS) is extremely rare. We are presenting two different cases of VS with significant facial weakness and reviewed the literature for similar cases. Methods and Results We are presenting two cases of VS with significant facial weakness. The first case was a 63-year-old male patient presented with 3 weeks' history of severe left-sided facial weakness (House–Brackmann [HB] grade V) and hearing loss. Magnetic resonance imaging (MRI) of the brain showed a tumor in the left internal auditory canal. Gross total removal with anatomical and physiological FN preservation was performed through a retrosigmoid approach under neurophysiological monitoring. FN function improved postoperatively to HB grade II after 16 months. The other case was 83-year-old male patient presented with sudden left-sided hearing loss and severe facial weakness (HB grade V). MRI of the brain 2.5 years before showed a left-sided (Class-T3A) cystic VS. The tumor was asymptomatic; wait-and-scan strategy was advised by the treating neurologist. Recent MRI of the brain showed approximately three times enlargement of the tumor with brain stem compression, extensive cystic changes, and suspected intratumoral hemorrhage. Surgery was performed; the tumor was subtotally removed through a retrosigmoid approach with intraoperative FN monitoring. The FN was anatomically preserved; however, physiological preservation was not possible. Severe facial weakness with incomplete lid closure persisted postoperatively. Conclusion Surgical treatment could be offered to cases of suspected VS presenting with facial weakness, as these cases may still have a chance for improvement especially in laterally located tumors.

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Incidence and Risk Factors of Delayed Facial Palsy After Vestibular Schwannoma Resection

Neurosurgery ◽

10.1227/neu.0000000000001015 ◽

2015 ◽

Vol 78 (2) ◽

pp. 251-255 ◽

Cited By ~ 10

Author(s):

Lucas P. Carlstrom ◽

William R. Copeland ◽

Brian A. Neff ◽

Marina L. Castner ◽

Colin L.W. Driscoll ◽

...

Keyword(s):

Risk Factors ◽

Vestibular Schwannoma ◽

Facial Palsy ◽

Tumor Resection ◽

Normal Function ◽

Early Postoperative Period ◽

Facial Nerve Function ◽

Facial Weakness ◽

Facial Function ◽

Study Inclusion

ABSTRACT BACKGROUND: Preservation of facial nerve function following vestibular schwannoma surgery is a high priority. Even those patients with normal to near-normal function in the early postoperative period remain at risk for delayed facial palsy (DFP). OBJECTIVE: To evaluate the incidence and prognosis of DFP and to identify risk factors for its occurrence. METHODS: A retrospective cohort study of 489 patients who underwent vestibular schwannoma resection at our institution between 2000 and 2014. Delayed facial palsy was defined as deterioration in facial function of at least 2 House-Brackmann (HB) grades between postoperative days 5 to 30. Only patients with a HB grade of I to III by postoperative day 5 were eligible for study inclusion. RESULTS: One hundred twenty-one patients with HB grade IV to VI facial weakness at postoperative day 5 were excluded from analysis. Of the remaining 368, 60 (16%) patients developed DFP (mean 12 days postoperatively, range: 5-25 days). All patients recovered function to HB grade I to II by a mean of 33 days (range: 7-86 days). Patients that developed DFP had higher rates of gross total resections (83% vs 71%, P = .05) and retrosigmoid approaches (72% vs 52%, P < .01). There was no difference in recovery time between patients who received treatment with steroids, steroids with antivirals, or no treatment at all (P = .530). CONCLUSION: Patients with a gross total tumor resection or undergoing a retrosigmoid approach may be at higher risk of DFP. The prognosis is favorable, with patients likely recovering to normal or near-normal facial function within 1 month of onset.

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Use of supramaximal stimulation to predict facial nerve outcomes following vestibular schwannoma microsurgery: results from a decade of experience

Journal of Neurosurgery ◽

10.3171/2012.10.jns12915 ◽

2013 ◽

Vol 118 (1) ◽

pp. 206-212 ◽

Cited By ~ 30

Author(s):

William R. Schmitt ◽

Jasper R. Daube ◽

Matthew L. Carlson ◽

Jayawant N. Mandrekar ◽

Charles W. Beatty ◽

...

Keyword(s):

Facial Nerve ◽

Vestibular Schwannoma ◽

Tumor Resection ◽

Constant Current ◽

Tumor Diameter ◽

Facial Weakness ◽

Tumor Removal ◽

Supramaximal Stimulation ◽

Facial Function

Object The goal of vestibular schwannoma surgery is tumor removal and preservation of neural function. Intraoperative facial nerve (FN) monitoring has emerged as the standard of care, but its role in predicting long-term facial function remains a matter of debate. The present report seeks to describe and critically assess the value of applying current at supramaximal levels in an effort to identify patients destined for permanent facial paralysis. Methods Over more than a decade, the protocol for stimulating and assessing the FN during vestibular schwannoma surgery at the authors' institution has consisted of applying pulsed constant-current stimulation at supramaximal levels proximally and distally following tumor resection to generate an amplitude ratio, which subtracted from 100% yields the degree to which the functional integrity of the FN “dropped off” intraoperatively. These data were prospectively collected and additional variables that might impact postoperative FN function were retrospectively reviewed from the medical record. Only patients with anatomically intact FNs and > 12 months of follow-up data were analyzed. Results There were 267 patients available for review. The average posterior fossa tumor diameter was 24 mm and the rate of long-term good (House-Brackmann Grade I–II) FN function was 84%. Univariate logistic regression analysis revealed that prior treatment, neurofibromatosis Type 2 status, tumor size, cerebellopontine angle extension, subjectively thinned FN at the time of operation, minimal stimulation threshold, percent dropoff by supramaximal stimulation (SMS), and postoperative FN function all correlated statistically (p < 0.05) with long-term FN function. When evaluating patients with significant FN weakness at the time of hospital discharge, only the percent dropoff by SMS remained a significant predictor of long-term FN function. However, the positive predictive value of SMS for long-term weakness is low, at 46%. Conclusions In a large cohort of patients, the authors found that interrogating intraoperative FN function with SMS is safe and technically simple. It is useful for predicting which patients will ultimately have good facial function, but is very limited in identifying patients destined for long-term facial weakness. This test may prove helpful in the future in tailoring less than gross-total tumor removal to limit postoperative facial weakness.

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HEARING PRESERVATION AFTER INTRACANALICULAR VESTIBULAR SCHWANNOMA RADIOSURGERY

Neurosurgery ◽

10.1227/01.neu.0000335783.70079.85 ◽

2008 ◽

Vol 63 (6) ◽

pp. 1054-1063 ◽

Cited By ~ 60

Author(s):

Ajay Niranjan ◽

David Mathieu ◽

John C. Flickinger ◽

Douglas Kondziolka ◽

L. Dade Lunsford

Keyword(s):

American Academy ◽

Head And Neck ◽

Vestibular Schwannoma ◽

Tumor Resection ◽

Hearing Preservation ◽

Neck Surgery ◽

Head And Neck Surgery ◽

Tumor Control ◽

Gamma Knife Stereotactic Radiosurgery

Abstract OBJECTIVE Tumor control, facial function preservation, and hearing preservation are important criteria for successful management of intracanalicular vestibular schwannomas, whether observation, microsurgery, or radiosurgery is chosen. We collected data prospectively to assess hearing preservation after intracanalicular vestibular schwannoma radiosurgery. METHODS Between 1987 and 2003, 96 patients (65 men and 31 women) underwent gamma knife stereotactic radiosurgery (SRS) for intracanalicular tumors. The median patient age was 54 years (range, 22–80 years). Hearing was graded using the Gardner-Robertson (GR) and the American Academy of Otolaryngology–Head and Neck Surgery classifications. Dose planning was performed on intraoperative stereotactic images using multiple 4-mm isocenters. The median tumor volume was 0.112 mm3 (range, 0.05–0.447 mm3), and the median margin dose was 13 Gy (range, 10–18 Gy). RESULTS The mean and median audiologic follow-up periods were 42 months and 28 months (range, 12–144 months), respectively. Serviceable hearing was preserved in 31 of 40 (77.5%) patients with initial American Academy of Otolaryngology–Head and Neck Surgery Class A hearing. Serviceable hearing was preserved in 40 of 79 (64.5%) patients with GR Grade I or II pre-SRS hearing. Ninety-two patients had GR Grade I, II, or III hearing before SRS, and GR Grade I, II, or III hearing was maintained in 78 patients (85%). Hearing grades improved in 7 patients. Facial and trigeminal nerve function was preserved in all patients. The tumor control rate (freedom from additional intervention) was 99.0% (95 of 96) at a median follow-up of 28 months (range, 12–144 months). One patient underwent tumor resection 18 months after radiosurgery. CONCLUSION SRS is a minimally invasive first-line management option for patients with intracanalicular tumors and provides high rates of hearing preservation with minimal morbidity.

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