Translabyrinthine Vestibular Schwannoma Research Articles

Skull Base Repair following Resection of Vestibular Schwannoma: A Systematic Review (Part 2: The Translabyrinthine Approach)

Abstract Objectives Despite advances in skull base reconstruction techniques, cerebrospinal fluid (CSF) leaks remain a relatively common complication after translabyrinthine (TL) vestibular schwannoma (VS) surgery. We conducted a systematic review to synthesize the repair techniques and materials used in TL VS surgery to prevent CSF leaks. Design A systematic review of studies published since 2000 reporting techniques to prevent CSF leaks during adult TL VS surgery was conducted. A narrative synthesis of primary repair protocols was produced, and a taxonomy was established. Additionally, the advantages, disadvantages, and associated CSF leak rates of different repair protocols were extracted. Results All 43 studies were case series, and 39 were retrospective. Repair strategies included heterogeneous combinations of autografts, xenografts, and synthetic materials. A taxonomy was produced, classifying repairs into seven distinct stages, including approaches to the dura, middle ear cleft, air cells, TL bony defect, extra-cranial soft tissue, postoperative dressings, and CSF diversion. The median postoperative incidence of CSF leaks was 6% (interquartile range: 0–10%). Conclusions This systematic review reveals substantial inter-institutional heterogeneity in intraoperative strategies to prevent CSF leaks following TL VS surgery. However, comparing these techniques is challenging due to the multiple predictive factors for CSF leaks and their inconsistent reporting. We propose a taxonomy of seven stages to classify operative techniques and materials aimed at preventing CSF leaks. We recommend that future evaluations should adopt a prospective approach encompassing data collection strategies that considers all operative stages described by our taxonomy.

Intraoperative Cochlear Nerve Monitoring for Vestibular Schwannoma Resection and Simultaneous Cochlear Implantation in Neurofibromatosis Type 2: A Case Series

Neurofibromatosis type 2 (NF2) often results in profound hearing loss and cochlear implantation is an emerging hearing rehabilitation option. However, cochlear implant (CI) outcomes in this population vary, and intraoperative monitoring to predict cochlear nerve viability and subsequent outcomes is not well-established. To review the use of intraoperative electrically evoked cochlear nerve monitoring in patients with NF2 simultaneous translabyrinthine (TL) vestibular schwannoma (VS) resection and cochlear implantation. A retrospective review was performed of 3 patients with NF2 that underwent simultaneous TL VS resection and cochlear implantation with electrical auditory brainstem response (eABR) measured throughout tumor resection. Patient demographics, preoperative assessments, surgical procedures, and outcomes were reviewed. Patients 1 and 3 had a reliable eABR throughout tumor removal. Patient 2 had eABR pretumor removal, but post-tumor removal eABR presence could not be reliably determined because of electrical artifact interference. All patients achieved auditory percepts upon CI activation. Patients 1 and 2 experienced a decline in CI performance after 1 yr and after 3 mo, respectively. Patient 3 continues to perform well at 9 mo. Patients 2 and 3 are daily users of their CI. Cochlear implantation is attainable in cases of NF2-associated VS resection. Intraoperative eABR may facilitate cochlear nerve preservation during tumor removal, though more data and long-term outcomes are needed to refine eABR methodology and predictive value for this population.

Is Cochlear Implantation Effective for Auditory Rehabilitation Following Vestibular Schwannoma Treatment?

Is Cochlear Implantation Effective for Auditory Rehabilitation Following Vestibular Schwannoma Treatment?

Clinical Significance of Middle Cerebellar Peduncle Ischemia After Translabyrinthine Vestibular Schwannoma Resection.

To assess clinical symptoms, signs, and radiographic evolution of middle cerebellar peduncle (MCP) diffusion restriction (DR) abnormalities following vestibular schwannoma (VS) resection. Retrospective chart and imaging review. Tertiary-referral neurotology and neurosurgery practice. All consecutive patients who underwent translabyrinthine VS resection over a 2-year period (August 2017-May 2019). Translabyrinthine craniotomy for VS resection. Magnetic resonance imaging (MRI) obtained on postoperative day 1 were reviewed for DR within the pons and cerebellum, with 3 months follow-up MRI to assess for evolution of these vascular changes. Of the 31 patients who met inclusion criteria, MRI demonstrated MCP DR consistent with acute ischemia in 29% (9/31). Of those, two showed corresponding T2 signal abnormalities on follow up MRI consistent with cerebrovascular accident (CVA) within the MCP. Both had severe gait ataxia and dysmetria requiring acute rehabilitation admission and significantly larger tumors (p = 0.02). The remaining seven were asymptomatic, and DR abnormality resolved without lasting radiographic changes. Brainstem compression was present in 100% of patients with postoperative MCP DR (mean MCP ipsilateral:contralateral ratio 0.59 ± 0.19), and 68.1% of those without (mean MCP ratio 0.71 ± 0.25), a difference that was not statistically significant (p = 0.14). In the two patients with CVA, MCP asymmetry persisted, whereas the asymmetry resolved in all others. Asymptomatic acute MCP ischemia discovered incidentally does not require intervention. However, when the ischemic area is large and patients are symptomatic, especially if an acute rehabilitation admission is required, surgeons should suspect true CVA.

Quality of Life After Translabyrinthine Vestibular Schwannoma Resection-Reliability of the German PANQOL Questionnaire.

To quantify the postoperative quality of life (QOL) of patients after translabyrinthine surgery for vestibular schwannoma (VS) using the German version of the Penn acoustic neuroma quality-of-life questionnaire (PANQOL) in a university hospital. The PANQOL questionnaire was administered to 72 patients who were treated in our department with translabyrinthine surgery for VS between January 2007 and January 2017. Descriptive evaluations of results were performed in addition to analyses of the reliability and convergent validity of the results and a subgroup analysis. For the first time, QOL was measured in German-speaking VS patients after translabyrinthine surgery. Cronbach's alpha for internal consistency and Guttman's split half, used as measures of reliability, showed values between 0.39 and 0.92 (raw alpha) and 0.58 and 0.98 (Lambda 4), respectively. The mean total PANQOL score of patients after translabyrinthine VS resection was 61.96. The domain "hearing" had the lowest score (50.87), while "facial dysfunction" had the highest score (74.88). Subgroup analysis showed that neither preoperative tumor size nor elapsed time postoperatively significantly influenced QOL outcomes. Depending on the different domains the German PANQOL questionnaire showed poor to good internal consistency, reliability, and convergent validity. Moreover, some VS patients suffer from reduced QOL for a long time after the translabyrinthine procedure, thus psycho-oncological care should be recommended in these cases.

Complications in translabyrinthine surgery of vestibular schwannoma

Objective: To evaluate the risk of complications associated with tumor size and patient’s age in translabyrinthine vestibular schwannoma surgery.Methods: 700 patients with vestibular schwannoma primarily underwent translabyrinthine surgery between 1988 and 2014. Pre- and postoperative data were collected in a database and incidence of the postoperative complications cerebrospinal fluid leakage, meningitis, intracranial hemorrhage (ICH), facial nerve function and mortality were assessed and related to the tumor size and patient’s age and retrospectively evaluated.Results: The tumor size significantly influenced the incidence of ICH and facial nerve dysfunction whereas age was correlated to facial nerve outcome.Conclusions: The translabyrinthine approach is a safe surgical procedure with relatively low risks of complications. The tumor size was significantly associated with a higher risk of ICH and facial nerve dysfunction whereas age only influenced the facial nerve outcome.

Prospective Evaluation of Patients Undergoing Translabyrinthine Excision of Vestibular Schwannoma with Concurrent Cochlear Implantation.

Translabyrinthine (TL) vestibular schwannoma (VS) resection may be accomplished with preservation of the cochlear nerve, permitting successful, concurrent cochlear implantation. In this single institution, Food and Drug Administration-approved feasibility study, we wished to determine the success and outcomes of concurrent cochlear implantation at the time of TL resection of VS. Prospective cohort. Tertiary referral center. Patients with small VS less than 1.5 cm in size. Concurrent TL VS resection and cochlear implantation. Sound localization and speech understanding. All cochlear nerves were anatomically preserved. Five out of seven patients had auditory precepts at the time of activation. At 1 month following surgery, AzBio scores (0 dB SNR, with sound front, noise to normal ear) were improved by an average of 10% with implant on, persisting to 6 months out from surgery. Localization 1 month after surgery was markedly improved with root mean square 78 degrees ±13 in the "implant off" condition and 41 ± 9 degrees in the "implant on" condition. Average tinnitus severity was reduced in subjects and speech and spatial hearing was improved on speech, spatial and qualities of hearing scale (SSQ). These data demonstrate preservation of electrical hearing in TL VS surgery is consistently possible, and although speech outcomes do not achieve the same levels seen with other etiologies of hearing loss, excellent improvement in sound localization, improved speech understanding, and substantial reductions in tinnitus are achieved.

Cochlear implantation for hearing rehabilitation in single-sided deafness after translabyrinthine vestibular schwannoma surgery.

The aim of the study was to investigate the option of cochlear implantation (CI) in resultant single-sided deafness associated with unilateral translabyrinthine resection of sporadic vestibular schwannoma (VS). This is a retrospective study performed at Tertiary Care Academic Centre. Following extensive counselling regarding the potential for delayed CI, translabyrinthine VS resection was performed and an intracochlear placeholder was inserted to allow later CI in 11 patients who showed intraoperative microscopic confirmation of preserved cochlear nerve anatomy. Follow-up magnetic resonance imaging (MRI) and promontory testing were performed 1year after surgery to confirm the absence of VS recurrence and viable cochlea. Confirmed CI candidates underwent a second procedure where the placeholder was removed and the CI inserted (4/11). Preimplant unaided and CI-aided evaluations at 12 and 24months were performed for subjective and objective hearing outcomes. Tinnitus suppression was also measured for implant on and off effects. Available audiological data for three patients demonstrated significant hearing benefits for 'speech from deaf/implanted side, noise from the normal-hearing side' in all three patients and localisation ability improved for 2/3 patients. Subjective findings presented similar results. For the two patients with preimplant tinnitus, complete suppression occurred during active CI. CI is beneficial for hearing rehabilitation and tinnitus reduction in SSD patients with remaining viable cochlear nerve after translabyrinthine VS surgery. Counselling on the risks of intracochlear placeholder insertion and the inherent limitations for ongoing MRI investigations of VS recurrence is essential.

Partial Hearing Preservation after Translabyrinthine Vestibular Schwannoma Resection: Case Report and Review of the Literature

Objectives To describe a unique case report of a patient who had partial hearing preservation after translabyrinthine (TL) removal of a vestibular schwannoma (VS). Study Design Case report. Methods The patient's chart was reviewed for hearing levels before and after surgery. Preoperative magnetic resonance imaging (MRI) was compared with postoperative MRI for determination of completeness of tumor removal. The literature on hearing preservation after TL resection is reviewed. Results A 42-year-old woman underwent a TL removal of a VS. The patient's preoperative pure tone average (PTA) was 70 dB and word recognition score (WRS) was 40%. Postoperatively, the patient was able to hear ambient noise in the surgical ear. Her bone conduction PTA was 70 dB, but the WRS score dropped to 2%. One year later, she continues to hear ambient noise and sound in the operative ear. Discussion This is the fifth reported case of partial hearing preservation after TL VS resection. It suggests that by preserving the vestibule and the fluids within the vestibule when possible, there maybe enough residual auditory neural structures for a traditional cochlear implant to benefit such a patient. In addition, preserving the incus when possible may help maintain air conduction to help patients with sound localization.

Magnetic Resonance Imaging after Translabyrinthine Complete Excision of Vestibular Schwannomas

The objective of this study is to determine whether magnetic resonance imaging (MRI) at 2 years following complete vestibular schwannoma (VS) excision using a translabyrinthine approach is sufficient to detect recurrent tumor. The study is set in a tertiary referral skull base unit. A service evaluation of a prospective database identified patients who underwent complete translabyrinthine VS excision with prospectively recorded MRI results at 2 and 5 years following surgery. The main outcome measures were evidence of tumor recurrence on MRI at 2 and 5 years after surgery. Of 314 patients in the study, all patients where MRI was reported to show no recurrence at 2 years (97%) also had no signs of recurrence on MRI at 5 years. All eight patients with MRI suspicious of recurrence (linear enhancement of internal auditory canal [IAC]) at 2 years had no progression on MRI at 5 to 15 years. One patient had evidence of definite recurrence (nodular enhancement of IAC) at 2 years, who went on to have radiosurgery at 8 years. Where patients have MRI with no linear enhancement of the IAC at 2 years, no further imaging is required. Where linear enhancement is seen, no change in enhancement at 5 years is reassuring and no further imaging is required.

Does Packing the Eustachian Tube Impact Cerebrospin al Fluid Rhinorrhea Rates in Translabyrinthine Vestibular Schwannoma Resections?

To calculate cerebrospinal fluid (CSF) leak rates for translabyrinthine (TL), middle cranial fossa (MCF), and retrosigmoid/suboccipital (SO) craniotomies performed for removal of vestibular schwannoma (VS) and analyze whether packing the eustachian tube (ET) in TL VS resections impacts CSF rhinorrhea rates. Retrospective. Tertiary care center. Chart review. Three hundred fifty-nine VS resections were reviewed in 356 patients ranging from 10 to 86 years of age. Two hundred thirty-one TL, 70 MCF, 53 SO, and 5 combined TL/SO procedures were analyzed. Total CSF leak rates (incisional, otorrhea, and rhinorrhea) were 14.2% for TL, 11.4% for MCF, and 13.2% for SO approaches. Differences in overall CSF leak rates were not statistically significant. For those who underwent TL craniotomies, 2 groups of patients were identified based on whether their ETs were packed during surgery. In 1 group, the incus was removed, the aditus enlarged, the ET packed, and the middle ear filled with muscle. In the second group, the aditus, epitympanum and middle ear were packed without removing the incus, and the ET was not packed. Of 148 patients who had their ET packed, 12 developed CSF rhinorrhea (8.1%). The CSF rhinorrhea rate for patients who did not have ET packing was 5.9% (3 of 51 patients). This difference was not statistically significant (p = 0.80). When Proplast was used to pack the ET (121 patients), the CSF rhinorrhea rate was 5.8%. Unfortunately, this material extruded in 4 of 121 patients (3.3%) and presented clinically as delayed purulent otorrhea. Cerebrospinal fluid leak rates were similar in patients undergoing TL, SO, and MCF approaches, and CSF rhinorrhea was not decreased by ET packing. Patients whose ETs are packed with Proplast are at risk for extrusion and otorrhea years after their initial VS resection.

Facial nerve function after translabyrinthine vestibular schwannoma surgery

To evaluate the long-term facial function of patients after translabyrinthine vestibular schwannoma [VS] surgery and identify factors that influence these outcomes. A retrospective review was performed that included 580 consecutive patients who underwent translabyrinthine craniotomy for removal of VS at a tertiary referral neurotologic practice between February 2000 and July 2004. A total of 512 patients who underwent primary microsurgical treatment of sporadic unilateral VS met inclusion criteria. Patient and tumor characteristics as well as perioperative complications are described. Perioperative and long-term facial function were evaluated in 392 patients who had at least 1-year follow-up. Complication rates after translabyrinthine craniotomy for VS are low. Patients with smaller tumors have significantly better postoperative facial function than those with larger tumors. Excellent long-term facial function can be expected in the majority of patients who undergo microsurgical removal of VS via the translabyrinthine approach. Alternative treatment strategies may need to be developed for the treatment of VS > 3.5 cm in order to maximize postoperative facial function.

Change in Tinnitus Handicap after Translabyrinthine Vestibular Schwannoma Excision

To evaluate the change in tinnitus handicap after translabyrinthine vestibular schwannoma excision. Prospective administration of the Tinnitus Handicap Inventory (THI) preoperatively and at 3 and 12 months postoperatively. : A tertiary referral neuro-otology clinic. A total of 149 patients from a series of 170 consecutive patients who had vestibular schwannomas excised between May 1998 and July 2002 and who had completed THIs preoperatively and at 3 and 12 months postoperatively. Translabyrinthine excision of a unilateral sporadic vestibular schwannoma. THI scores. The number of patients with moderate or severe handicap was 21 (14%) in the preoperative group and 21 (14%) in the 12-month postoperative group. No significant differences in group data were found comparing (by Wilcoxon signed rank test) preoperative data with 3 months postoperative data (p = 0.09), preoperative data with 12 months postoperative data (p = 0.09), and 3 months postoperative data with 12 months postoperative data (p = 0.33). Considering group data, tinnitus handicap is neither alleviated nor exacerbated by translabyrinthine surgery. The application of the validated 20-point criteria for significant change in the status of an individual patient indicates that tinnitus handicap was worse in 10 (6.5%), unchanged in 129 (87%), and better in 10 (6.5%). The findings of the current study can be used during preoperative patient counseling. In particular, the clinician is now able to take an informed and positive stance about the tinnitus handicap to be expected postoperatively.