Hearing preservation in medial vestibular schwannomas

Object Vestibular schwannomas (VSs) with no or little extension into the internal auditory canal have been addressed as a clinical subentity carrying a poor prognosis regarding hearing preservation, which is attributed to the initially asymptomatic intracisternal growth pattern. The goal in this study was to assess hearing preservation in patients who underwent surgery for medial VSs. Methods A consecutive series of 31 cases in 30 patients with medial VSs (mean size 31 mm) who underwent surgery between 1997 and 2005 via a suboccipitolateral route was evaluated with respect to pre- and postoperative cochlear nerve function, extent of tumor removal, and radiological findings. Intraoperative monitoring of brainstem auditory evoked potentials was performed in all patients with hearing. Patients were reevaluated at a mean of 30 months following surgery. Results Preoperative hearing function revealed American Academy of Otolaryngology–Head and Neck Surgery Foundation Classes A and B in 7 patients each, Class C in 4, and D in 9. Four patients presented with deafness. Hearing preservation was achieved in 10 patients (Classes A–C in 2 patients each, and Class D in 4 patients). Tumor removal was complete in all patients with hearing preservation, except for 2 patients with neurofibromatosis. In 4 patients a planned subtotal excision was performed due to the individual's age or underlying disease. In 1 patient a recurrent tumor was completely removed 3 years after the initial procedure. Conclusions The cochlear nerve in medial VSs requires special attention due to the atypical intracisternal growth pattern. Even in large tumors, hearing could be preserved in 37% of cases, since the cochlear nerve in medial schwannomas may not exhibit the adherence to the tumor capsule seen in tumors with comparable size involving the internal auditory canal.

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Preservation of hearing in patients undergoing excision of acoustic neuromas and other cerebellopontine angle tumors

Journal of Neurosurgery ◽

10.3171/jns.1985.63.2.0168 ◽

1985 ◽

Vol 63 (2) ◽

pp. 168-174 ◽

Cited By ~ 47

Author(s):

Charles H. Tator ◽

Julian M. Nedzelski

Keyword(s):

Tumor Size ◽

Cerebellopontine Angle ◽

Internal Auditory Canal ◽

Hearing Preservation ◽

Cochlear Nerve ◽

Consecutive Series ◽

Speech Discrimination ◽

Content Type ◽

Acoustic Neuromas ◽

Fine Print

✓ Microsurgical techniques have made it possible to identify and preserve the cochlear nerve from its origin at the brain stem and along its course through the internal auditory canal in patients undergoing removal of small or medium-sized acoustic neuromas or other cerebellopontine angle (CPA) tumors. In a consecutive series of 100 patients with such tumors operated on between 1975 and 1981, an attempt was made to preserve the cochlear nerve in 23. The decision to attempt to preserve hearing was based on tumor size and the degree of associated hearing loss. In cases of unilateral acoustic neuroma, the criteria for attempted preservation of hearing were tumor size (2.5 cm or less), speech reception threshold (50 dB or less), and speech discrimination score (60% or greater). In patients with bilateral acoustic neuromas or tumors of other types, the size and hearing criteria were significantly broadened. All patients were operated on through a suboccipital approach. Hearing was preserved postoperatively in six (31.6%) of the 19 patients with unilateral acoustic neuromas, although the cochlear nerve was preserved in 16. Of the six patients with postoperative hearing, three retained excellent hearing, and the other three had only sound awareness and poor discrimination. Hearing was preserved in three cases with other CPA tumors, including an epidermoid cyst and small petrous meningiomas in the internal auditory canal. Of the two cases with bilateral tumors, hearing was preserved in one. Of the 23 patients in whom hearing preservation was attempted, nine (39.1%) had some postoperative hearing, which in six was equal to or better than the preoperative level. Thus, it is worthwhile to attempt hearing preservation in selected patients with CPA tumors.

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Retrosigmoid Approach for Vestibular Schwannoma

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0038-1673703 ◽

2018 ◽

Vol 80 (S 03) ◽

pp. S271-S271

Author(s):

Mohammed Aref ◽

Katherine Kunigelis ◽

Stephen P. Cass ◽

A. Samy Youssef

Keyword(s):

Vestibular Schwannoma ◽

Tumor Resection ◽

Internal Auditory Canal ◽

Hearing Preservation ◽

Neck Surgery ◽

Cochlear Nerve ◽

Management Options ◽

Suppurative Otitis Media ◽

History Of ◽

The Right

Vestibular schwannoma is a benign tumor that affects 3% of the population, but accounts for 85% of tumors occurring at the cerebellopontine angle (CPA). In this case, we present a 48-year-old female with history of cholesteatoma on the right and chronic suppurative otitis media on the left who presented with an 18 month history of bilateral hearing loss, worse on the right. Investigations revealed a right sided vestibular schwannoma measuring 1.6 cm in diameter. Audiogram revealed an AAO–HNS (American Academy of Otolaryngology–Head and Neck Surgery) class C hearing on the right and class B on the left. There are several management options for this size of vestibular schwannoma including observation and radiosurgery. However, preserving cochlear nerve function remains a challenging enterprise. Furthermore, the ideal management that confers the highest chance of hearing preservation remains heavily debated. Given the patient's young age, the goal of hearing preservation and the tumor size/extension into the CPA, surgery was decided through a right retrosigmoid transmeatal approach for tumor resection with intraoperative brain auditory evoked responses monitoring. For hearing preservation, we emphasize few important dissection techniques: tumor debulking from the top first to avoid early manipulation of the cochlear nerve at the bottom of the tumor, sharp dissection from medial to lateral off the vestibular nerve which is kept intact as a tension band to minimize cochlear nerve manipulations, and limit the drilling of the posterolateral wall of the internal auditory canal (IAC) medial to the labyrinth and endolymphatic apparatus. Postoperatively, the patient was discharged home within 2 days, with imaging showing a gross total resection. Follow-up audiogram shows unchanged pure tone thresholds.The link to the Video can be found at: https://youtu.be/Z5ftkpJN5k8.

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Effect of tumor removal on tinnitus in patients with vestibular schwannoma

Journal of Neurosurgery ◽

10.3171/2009.3.jns081053 ◽

2010 ◽

Vol 112 (1) ◽

pp. 152-157 ◽

Cited By ~ 33

Author(s):

Katsuharu Kameda ◽

Tadahisa Shono ◽

Kimiaki Hashiguchi ◽

Fumiaki Yoshida ◽

Tomio Sasaki

Keyword(s):

Vestibular Schwannoma ◽

Hearing Preservation ◽

Cochlear Nerve ◽

Vestibular Schwannomas ◽

Tumor Removal ◽

Significant Difference ◽

Before And After ◽

The Status ◽

Lateral Suboccipital Approach ◽

Suboccipital Approach

Object Tinnitus is one of the most common symptoms in patients with vestibular schwannomas (VSs), but the effect of surgery on this symptom has not been fully evaluated. The aim of this study was to define the effect on tinnitus of tumor removal, cochlear nerve resection, and useful hearing preservation in patients with VSs. Methods The authors retrospectively analyzed the status of tinnitus before and after surgery in 242 patients with unilateral VSs who underwent surgery via the retrosigmoid lateral suboccipital approach. Results Of 242 patients, 171 (70.7%) complained of tinnitus before surgery; the symptom disappeared in 25.2%, improved in 33.3%, remained unchanged in 31.6%, and worsened in 9.9% of these cases after tumor removal. In the 171 patients with preoperative tinnitus, the cochlear nerve was resected in 85 (49.7%) and preserved in 86 (50.3%), but there was no significant difference in the incidence of postoperative tinnitus between these 2 groups (p = 0.293). In the 71 patients without preoperative tinnitus, the symptom developed postoperatively in 6 cases (8.5%). Among those without preoperative tinnitus, the cochlear nerve was resected in 45 cases (63.4%) and tinnitus appeared postoperatively in 3 (6.7%). The authors also analyzed the association between postoperative tinnitus and useful hearing preservation, but could not find any statistically significant association between the 2 factors (p = 0.153). Conclusions Tumor removal via the retrosigmoid lateral suboccipital approach may provide some chance for improvement of tinnitus in patients with VSs; however, neither cochlear nerve resection nor useful hearing preservation affects the postoperative development of tinnitus.

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Spreading of the vestibular schwannoma into porus acusticus internus. Endoscopic removal possibilities

OTORHINOLARYNGOLOGY 2-3(2) 2019 - OTORHINOLARYNGOLOGY ◽

10.37219/2528-8253-2018-1-40 ◽

2018 ◽

pp. 40-44

Author(s):

Orest Palamar ◽

Andriy Huk ◽

Dmytro Okonskyi ◽

Ruslan Aksyonov ◽

Dmytro Teslenko

Keyword(s):

Vestibular Schwannoma ◽

Internal Auditory Canal ◽

Residual Tumor ◽

Endoscopic Technique ◽

Vestibular Schwannomas ◽

Endoscopic Removal ◽

Tumor Removal ◽

Tumor Spread ◽

Microsurgical Technique ◽

Tumor Visualization

Aim: To investigate the features of the vestibular schwannoma spread into the internal auditory canal and the possibilities of endoscopic removal. Objectives: To improve tumor visualization in the internal auditory canal; to create a sufficient view angle for tumor removal during endoscopic opening of the internal auditory canal. Materials and methods: The results of surgical treatment of 20 patients with vestibular schwannomas in which the tumor spread to the internal auditory canal were analyzed. Microsurgical tumor removal was performed in 14 cases; Fully endoscopic removal of vestibular schwannomas was performed in 6 cases. The internal auditory canal opening was performed in 14 cases using microsurgical technique and in 6 cases with fully the endoscopic technique. Results: Gross total removal was achieved in 18 cases, subtotal removal in 2 cases. The tumor spread into the internal auditory canal was removed in all cases (100%). Opening the internal auditory canal using the endoscopic technique allows to increase the view angle (up to 20%) and to visualize along the axis of canal. Conclusions: 1) Endoscopic assistance technique allows to improve residual tumor visualization much more better then microsurgical technique; 2) Internal auditory canal opening using endoscopic technique is much more effective than the microsurgical technique (trepanning depth is larger); 3) Endoscopic methods for the internal auditory canal opening allows to increase canal angle view up to 20% (comparing to the microsurgical view).

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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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Internal Auditory Canal Reconstruction After Vestibular Schwannomas Removal Through Retrosigmoid-Transmeatal Approach

JBNC - JORNAL BRASILEIRO DE NEUROCIRURGIA ◽

10.22290/jbnc.v26i3.1349 ◽

2018 ◽

Vol 26 (3) ◽

pp. 237-241

Author(s):

Ricardo Ramina ◽

Gustavo Simiano Jung ◽

Erasmo Barros Da Silva Jr ◽

Guilherme José Agnoletto ◽

Luis Fernando Moura Da Silva Jr ◽

...

Keyword(s):

Cranial Nerves ◽

Internal Auditory Canal ◽

Jugular Foramen ◽

Vestibular Schwannomas ◽

Fat Tissue ◽

Resonance Imaging ◽

Tumor Removal ◽

Postoperative Mri ◽

Csf Leakage ◽

Magnetic Resonance Imaging Mri

Objectives: To present a technique of internal auditory canal (IAC) reconstruction using a pediculated dural flap, after removal of vestibular schwannomas through the retrosigmoid craniotomy. Methods: From a series of 213 patients with vestibular schwannomas operated between January 2008 and March 2016 through the retrosigmoid-transmeatal approach, 183 underwent reconstruction of the internal auditory canal with a pediculated dural flap. The IAC was drilled towards the fundus preserving the labyrinthine structures. The dura mater over the IAC was dissected from the bone, remaining pediculated at the entrance of the jugular foramen. This dural flap was used to cover the cranial nerves inside the IAC after tumor removal. Opened mastoid cells and the IAC were closed with muscle or fat grafts and fibrin glue. Results: Reconstruction of the IAC using the described technique was possible in in 183 cases. Fifteen patients (6.8%) developed postoperative cerebrospinal fluid (CSF) leakage and seven patients required reoperation (3.2%) to close the fistulae. Postoperative magnetic resonance imaging (MRI) examinations showed the presence of CSF within the IAC around the preserved cranial nerves. Conclusions: This technique of IAC reconstruction after surgical resection of vestibular schwannomas may avoid scar and adhesion of muscle or fat tissue with preserved cranial nerves, allowing CSF enter inside the IAC. It may help to identify tumor remnants and/or recurrences in postoperative MRI examinations. Comparative studies are needed to evaluate if this technique improves postoperative hearing and facial nerve outcomes.

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Suboccipital Retrosigmoid Approach for Removal of Vestibular Schwannomas: Facial Nerve Function and Hearing Preservation

Neurosurgery ◽

10.1227/01.neu.0000154059.34990.b8 ◽

2005 ◽

Vol 56 (3) ◽

pp. 560-570 ◽

Cited By ~ 34

Author(s):

Ivan Ciric ◽

Jin-cheng Zhao ◽

Sami Rosenblatt ◽

Richard Wiet ◽

Brian O'shaughnessy

Keyword(s):

Prognostic Factors ◽

Surgical Technique ◽

Facial Nerve ◽

Hearing Preservation ◽

Vestibular Schwannomas ◽

Neurophysiological Monitoring ◽

Nerve Function ◽

Facial Nerve Function ◽

Tumor Removal ◽

Neurovascular Anatomy

Abstract IN THIS REPORT, we discuss the pertinent bony, arachnoid, and neurovascular anatomy of vestibular schwannomas that has an impact on the surgical technique for removal of these tumors, with the goal of facial nerve and hearing preservation. The surgical technique is described in detail starting with anesthesia, positioning, and neurophysiological monitoring and continuing with the exposure, technical nuances of tumor removal, hemostasis, and closure. Positive prognostic factors for hearing preservation are also highlighted.

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Preservation of hearing after surgery for acoustic schwannomas: correlation between cochlear nerve function and operative findings

Journal of Neurosurgery ◽

10.3171/jns.1994.80.5.0844 ◽

1994 ◽

Vol 80 (5) ◽

pp. 844-848 ◽

Cited By ~ 20

Author(s):

Hiromichi Umezu ◽

Tadashi Aiba

Keyword(s):

Tumor Size ◽

Hearing Preservation ◽

Cochlear Nerve ◽

Hearing Level ◽

Tumor Removal ◽

Content Type ◽

Acoustic Schwannoma ◽

Operative Findings ◽

Total Tumor Removal ◽

Results Of Surgery

✓ The results of surgery in 66 patients with acoustic schwannoma in whom total tumor removal was accomplished are reviewed in terms of the relationships among tumor size, preoperative hearing level, operative findings (including the shape and location of the cochlear nerve at the tumor surface), and the extent of post-operative hearing preservation. Both tumor size and the preoperative hearing level were correlated with the shape of the cochlear nerve, which more frequently formed a solid bundle when the tumor was small or the preoperative hearing was excellent. Hearing was retained postoperatively only in cases in which the nerve formed a solid bundle and could be differentiated and separated from the tumor capsule without difficulty. These findings suggest that tumor size and preoperative hearing level, which have been reported to be the main prognostic factors of postoperative hearing preservation, may influence the results of surgery for acoustic schwannoma through the shape of the cochlear nerve.

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Hearing Preservation after Acoustic Neuroma Surgery with Intraoperative Direct Eighth Cranial Nerve Monitoring: Part II. A Classification of Results

Otolaryngology ◽

10.1177/01945998860953p104 ◽

1986 ◽

Vol 95 (3_part_1) ◽

pp. 285-291 ◽

Cited By ~ 52

Author(s):

Herbert Silverstein ◽

Alan Mcdaniel ◽

Horace Norrell

Keyword(s):

Intraoperative Monitoring ◽

Hearing Preservation ◽

Cochlear Nerve ◽

Class Iii ◽

Tumor Removal ◽

Eighth Cranial Nerve ◽

Nerve Monitoring ◽

Eighth Nerve ◽

Auditory Evoked Response ◽

Acoustic Neuromas

Since the advent of brainstem auditory evoked response audiometry and computerized tomography, small acoustic neuromas are more frequently found. Often the patient has serviceable hearing, which we would like to preserve during complete tumor removal. Since 1978, sixteen patients with acoustic neuromas have been operated upon through the retrosigmoid suboccipital approach, with the goal of hearing preservation. In 1983, we began using intraoperative direct eighth nerve monitoring, which produced a rapid assessment of cochlear nerve function during the excision of small acoustic neuromas. The tumors varied in size from intracanalicular lesions to one lesion with a 3.0 cm protrusion medial to the porus acousticus. In eight of sixteen cases, intraoperative monitoring was used, and in four of the patients hearing was preserved. In eight cases, intraoperative monitoring was not used, and hearing was preserved in only two patients. The overall success rate—in total tumor removal with hearing preservation—was 37%. Hearing was preserved in six of eight patients who had tumors which measured less than 1.5 cm. In this group of cases, two of the patients had a Class I good hearing result (PTA 0 to 30 dB and 70 to 100% discrimination), one patient had Class III nonserviceable hearing, (PTA 65 to 75 dB and 25 to 45% discrimination), and three patients had Class IV poor hearing, (PTA 80 to 100 dB and 0 to 20% discrimination). We found that continuous monitoring of direct eighth-nerve-evoked action potentials were extremely valuable and rapidly indicated reversible cochlear nerve trauma.

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Koos Grade IV Vestibular Schwannomas: Considerations on a consecutive series of 60 cases. Searching for the Balance Between Preservation of Function and Maximal Tumor Removal

10.21203/rs.3.rs-210753/v1 ◽

2021 ◽

Author(s):

Luciano Mastronardi ◽

Alberto Campione ◽

Fabio Boccacci ◽

Carlo Giacobbo Scavo ◽

Ettore Carpineta ◽

...

Keyword(s):

Functional Results ◽

Hearing Preservation ◽

High Rate ◽

Vestibular Schwannomas ◽

Maximum Diameter ◽

Consecutive Series ◽

Tumor Diameter ◽

Impaired Hearing ◽

Class B ◽

The Right

Abstract Purpose Koos Grade IV vestibular schwannomas (VS) (maximum diameter >3cm) compress the brainstem and displace the fourth ventricle. Microsurgical resection with attention to the right balance between preservation of function and maximal tumour removal is the treatment of choice.Methods Our series consists of 60 consecutive patients with unilateral VS, operated on from December 2010 to July 2019. All patients underwent microsurgical removal via the retrosigmoid approach. The adherence of VS’ capsule to surrounding nervous structures and the excessive tendency of tumor to bleed during debulking, because of a redundant vascular architecture, was evaluated by reviewing video records. Microsurgical removal of tumor was classified as total (T), near-total (NT: residue<5%), subtotal (ST: residue 5-10%) or partial (P: residue>10%).Results Maximal mean tumor diameter was 3,97cm (SD±1,13; range 3,1-5,8cm). Preoperative severely impaired hearing or deafness (AAO-HNS Classes C-D) was present in 52 cases (86,7%). Total or NT resection was accomplished in 46 cases (76,7%), 65,8% in cases with and 95,4% without tight adhesion of capsule to nervous structures (p<0,001). Endoscopic-assisted microsurgical removal of VS in the IAC was performed in 23 patients: in these cases a T resection was obtained in 78,3% versus 45,9% of microsurgery only (p<0,001).The capsule of VS was tightly adherent to nervous structures in 63,3% of patients, whereas hypervascular high-bleeding tumors represented 56,7%. Hearing preservation was possible in 2 out of 8 patients with preoperative class B hearing. At last follow-up, 34 patients (56,7%) had a normal postoperative FN outcome (HBI), 9 (15,0%) were HBII, 8 (13,3%) HBIII, and 9 (15,0%) HBIV. Total-NT resection of solid and low-bleeding VS, without tight capsule adhesion was associated with better FN outcome. Mortality was zero; permanent complications were observed in 2 cases (diplopia, hydrocephalus), transient in 9.Conclusions Microsurgery of Koos Grade IV VS seems to be associated with more than acceptable functional results, with high rate of T and NT removal of tumor. Long-term FN results seem to be worse in patients with cystic Koos Grade IV VS, in cases with tight capsule adherences to nervous structures and in high-bleeding tumors.

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