Superior petrosal vein sacrifice in translabyrinthine approach for resection of vestibule schwannoma.

PURPOSE: The aim of this study was to evaluate the safety and surgical outcome of superior petrosal vein (SPV, Dandy's vein) sacrifice in translabyrinthine approach (TLA) for resection of vestibule schwannoma (VS) as compared with SPV preservation, with further investigation of preoperational factors associated with the implement of SPV sacrifice. METHODS: The authors prospectively collected data from patients surgically treated for VS through TLA between June 2021 and April 2022 at the Gruppo Otologico. RESULTS: There were 30 and 49 patients in SPV sacrifice and preservation groups, respectively. SPV sacrifice group had significantly larger tumor size (2.46 vs. 1.40 cm), less percentage of solid tumor (26.7% vs. 83.7%), higher incidence of brainstem compression (80% vs. 26.5%), and higher percentage of facial numbness (20.0% vs. 4.1%) than SPV preservation group. Gross total resection (GTR) rates were 73.3% after SPV sacrifice and 87.8% after SPV preservation. Facial nerve preservation rates were similar. No complication related with SPV sacrifice was observed. Logistic regression analysis showed tumor size and complete solid consistency as significant risk factors associated with SPV sacrifice. ROC curve further demonstrated tumor size as a fair predictor (AUC = 0.833), with optimum cutoff value of 1.68 cm. CONCLUSION: SPV sacrifice via TLA as needed is a safe and effective maneuver for removal of relatively large VS. Tumor size and consistency can be used as a guidance in preoperational decision-making, with cutoff value of 1.68 cm and cystic formation as predictive indicators.

Prevention of cerebrospinal fluid leak after vestibular schwannoma surgery: a case-series focus on mastoid air cells' partition.

BACKGROUND: Petrous bone pneumatization may be related to cerebrospinal fluid (CSF) leak secondary to vestibular schwannoma surgery. OBJECTIVE: To assess the association between petrous bone pneumatization and CSF leak in vestibular schwannoma surgery. METHODS: A retrospective study included 222 consecutive vestibular schwannoma patients treated via a retrosigmoid or translabyrinthine approach in a 17-year period in one University Hospital. Association of CSF leak and petrous bone pneumatization, as seen on CT scans, was assessed on ANOVA and Student's t or Chi-squared test in case of non-parametric distribution. RESULTS: One hundred and 75 resections were performed on a retrosigmoid approach and 47 on a translabyrinthine approach. Mean age was 53.6 ± 12.9 years. Mean follow-up was 5 years 6 months. Twenty-six patients (11.7%) showed CSF leak and 8 (3.6%) meningitis. Approach (p = 0.800), gender (p = 0.904), age (p = 0.234), body-mass index (p = 0.462), tumor stage (p = 0.681) and history of schwannoma surgery (p = 0.192) did not increase the risk of CSF leak. This risk was unrelated to mastoid pneumatization (p = 0.266). There was a highly significant correlation between internal acousticus meatus (IAM) posterior wall pneumatization and CSF leak after retrosigmoid surgery (p = 0.008). Eustachian tube packing in the translabyrinthine approach did not decrease risk of CSF leak (p = 0.571). CONCLUSION: Degree of petrous bone pneumatization was not significantly related to risk of CSF leak, but pneumatization of the posterior IAM wall increased this risk in retrosigmoid surgery. Eustachian tube packing in the translabyrinthine approach is not sufficient to prevent postoperative CSF leak. Both approaches had similar rates of CSF leaks, around 12%.

Phenotypical variability of the sigmoid sinus in translabyrinthine and retrosigmoid surgeries.

INTRODUCTION: We hypothesized that the cranial phenotype influences the shape of the posterior cranial fossa and the relative position of the sigmoid sinus. MATERIALS AND METHODS: The topography of the sigmoid sinus was studied on 26 magnetic resonance venograms and 35 embalmed cadavers by morphometric analysis, dissection, and photo modeling techniques. RESULTS: The data show that the transverse diameter of the posterior cranial fossa correlates positively with the laterolateral diameter of the skull. The majority of cases with the low-anterior position of the sigmoid sinus were recorded in the brachycephalic group (82%), while the high-posterior localization of the sigmoid sinus was typical for the dolichocephalic patients (63%). The results of the ANOVA test confirm the significance of differences. CONCLUSIONS: The shape of the skull reflects the morphology of the posterior cranial fossa and influences the topographic characteristics of the sigmoid sinus that must be considered in the selection of surgical approach to the inner ear and pontocerebellar angle.

Large and small vestibular schwannomas: same, yet different tumors.

BACKGROUND: Vestibular schwannomas (VS) present at variable size with heterogeneous symptomatology. Modern treatment paradigms for large VS include gross total resection, subtotal resection (STR) in combination with observation, and/or radiation to achieve optimal function preservation, whereas treatment is felt to be both easier and safer for small VS. The objective is to better characterize the presentation and surgical outcomes of large and small VS. METHODS: We collected data of patients who had surgically treated VS with a posterior fossa diameter of 4.0 cm or larger (large tumor group, LTG) and smaller than 1.0 cm in cisternal diameter (small tumor group, STG). Statistical significance was defined as p < 0.05. RESULTS: LTG included 48 patients (average tumor size: 44.9 mm) and STG 38 (7.9 mm). Patients in STG presented more frequently with tinnitus and sudden hearing loss. Patients in LTG underwent more STR than STG (50.0% vs. 2.6%, p < 0.0001). LTG had more complications (31.3% vs. 13.2%, p = 0.049). Postoperative facial nerve function in STG was significantly better than LTG. STG had better hearing preoperatively (p < 0.0001) and postoperatively than LTG (p = 0.0002). Postoperative headache was more common in STG (13.2% vs. 2.1%, p = 0.045). The rate of recurrence/progression needing treatment was not statistically different between the groups (12.5% in LTG vs. 7.9% in STG, p = 0.49). Those patients who required periprocedural cerebrospinal fluid diversion had higher risk of infection (20.8% vs 4.8%, p = 0.022). CONCLUSION: Large and small VS present differently. LTG showed more unsatisfactory outcomes in facial nerve function and postoperative hearing despite maximal efforts undertaken toward function-preservation strategy; however, similar tumor control was achieved.

Postoperative headache after surgical treatment of cerebellopontine angle tumors: a systematic review.

PURPOSE: Postoperative headache (POH) is a complication that occurs after surgical resection of cerebellopontine angle (CPA) tumors. The two most common surgical approaches are the translabyrinthine (TL), and retrosigmoid (RS) approach. The objective of this systematic review was to investigate whether POH occurs more frequently after RS compared to TL approaches. METHODS: A systematic search was conducted in Cochrane, Pubmed and Embase. Studies were included if POH after CPA tumor removal was reported and both surgical approaches were compared. The methodological quality of the studies was assessed using the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. RESULTS: In total, 3,942 unique articles were screened by title and abstract. After the initial screening process 63 articles were screened for relevance to the inquiry, of which seven studies were included. Three studies found no significant difference between both surgical approaches (p = 0.871, p = 0.120, p = 0.592). Three other studies found a lower rate of POH in the TL group compared to the RS group (p = 0.019, p < 0.001, p < 0.001). Another study showed a significantly lower POH rate in the TL group after one and six months (p = 0.006), but not after 1 year (p = 0.6). CONCLUSION: The results of this systematic review show some evidence of a lower rate of POH in favor of the TL approach versus the RS approach for CPA tumor resection. Prospective research studies are needed to further investigate this finding.

Translabyrinthine approach to internal auditory meatus: A retrospective study.

BACKGROUND: Ear and the lateral skull base surgery is challenging and yet fascinating for a Neuro-otologist. A thorough knowledge of the complex anatomy is indispensable for the surgeon in order to provide the best possible care. METHODS: The aim of the study was to highlight the present day indications for translabyrinthine approach to IAM from a Neuro-otologist perspective. RESULTS: There were a total of 7 patients who underwent Translabyrinthine approach at our centre. In the present study we have reported cases of Vestibular Schwannoma, Facial nerve schwannoma, Cholesteatoma involving the IAM, Meniere's disease with refractory vertigo which were managed via translabyrinthine approach. We also encountered, probably the first reported case, tuberculoma of the IAM which was clinical suspected to be vestibular schwannoma. CONCLUSION: The article presents different clinical situations where this approach can be suitably utilized and has been dealt with via a retrospective study encountered at our centre.

Acoustic schwannoma with intracochlear extension and primary intracochlear schwannoma: removal through translabyrinthine approach with facial bridge cochleostomy and transcanal approach.

Intracochlear schwannomas can occur either as an extension of a larger tumor from the internal auditory canal, or as a solitary labyrinthine tumor. They are currently removed via a translabyrinthine approach extended to the basal turn, adding a transotic approach for tumors lying beyond the basal turn. Facial bridge cochleostomy may be associated with the translabyrinthine approach to enable the whole cochlea to be approached without sacrificing the external auditory canal and tympanum. We describe seven cases, five of which underwent cochlear schwannoma resection with facial bridge cochleostomy, one case with the same procedure for a suspect tumor and one, previously subjected to radical tympanomastoidectomy, who underwent schwannoma resection via a transotic approach. Facial bridge cochleostomy involved removing the bone between the labyrinthine and tympanic portions of the fallopian canal, and exposing the cochlea from the basal to the apical turn. Patients' recovery was uneventful, and long-term magnetic resonance imaging showed no residual tumor. Facial bridge cochleostomy can be a flexible extension of the translabyrinthine approach for tumors extending from the internal auditory canal to the cochlea. The transcanal approach is suitable for the primary exclusive intralabyrinthine tumor. The indications for the different approaches are discussed.

Transcanal surgery for vestibular schwannomas: a pictorial review of radiological findings, surgical anatomy and comparison to the traditional translabyrinthine approach.

The most popular approaches for vestibular schwannoma (VS) removal are retrosigmoid, middle cranial fossa and translabyrinthine (TL). All require a certain degree of invasivity, bone removal, or brain manipulation. Recently, the authors described the transcanal transpromontorial approaches (TTA), which allow the inner ear to be accessed directly through the external auditory canal (EAC), either with a microscopic (Expanded TTA, or ExpTTA) or even an exclusive endoscopic technique (Endoscopic TTA, or EndoTTA). The advantages compared to traditional approaches are a direct view of the internal auditory canal (IAC) from lateral to medial, very little or no superficial tissue dissection and very little petrous bone drilling. In summary, from an anatomical point of view, they could be considered to be minimally invasive approaches. The radiologic outcome and the anatomical correspondence of these new approaches are described so as to share with the readers the possible radiologic findings and to compare and differentiate them from classic transpetrous approaches such as the TL approach. LEVEL OF EVIDENCE: 4.

[Surgical techniques for treatment of vestibular schwannoma]. / Chirurgische Techniken zur Behandlung des Vestibularisschwannoms.

BACKGROUND: Microsurgical resection of vestibular schwannomas is demanding, even if not all of these tumors represent a challenge for experienced surgeons. In order to make the right decisions when it comes to balancing the extent of tumor resection with preservation of function, the surgeon must possess detailed knowledge of the surgical techniques and also have mastered these. OBJECTIVE: The current article describes the state-of-the-art of the three major microsurgical techniques for resection of vestibular schwannomas, their pearls and their perils. MATERIALS AND METHODS: The literature-based review of the three surgical techniques is complemented by a discussion of operative nuances and weighting of advantages and possible complications based on the authors' own experience. RESULTS: The translabyrinthine, retrosigmoidal, and subtemporal microsurgical approaches are well documented in the literature regarding their modifications and the achievable surgical results. Hearing preservation is possible with the latter two approaches. The choice of approach and the preservation of neural function depend primarily on the size of the tumor and pre-existing neurologic deficits. Preoperative diagnostics and preparation differ only for semi-sitting patient positioning, where transesophageal echocardiography is required. The classic surgical techniques have been supplemented by fine-tuned electrophysiologic monitoring, endoscopic views, special microinstruments, and intraoperative image guidance. CONCLUSION: The choice of surgical approach often depends on the personal preference and experience of the surgeon. Preoperative hearing and tumor extension are the main objective selection criteria.

Decision making in dissection range of temporal bone: refinements to enlarged translabyrinthine approach.

The aim of the study was to describe the refinements to the classic enlarged translabyrinthine approach (ETLA) by modifying the bony dissection range of temporal bone and to analyze the main outcomes achieved in a series of vestibular schwannoma (VS) cases submitted to microsurgery by ETLA. This was a retrospective study of 382 patients who underwent VS surgical removal via ETLA between January 2001 and December 2012. Among those cases, 332 were via classic ETLA, while 28 cases were via ETLA with blind sac technique and middle ear eradication and 22 via transotic approach. Total tumor removal was achieved in 368 cases, whereas near total removal in 11 patients and subtotal in 3 patients. In cases of large VS (>3 cm) via classic ETLA, good short-term and long-term facial nerve function (HB I-II) was gained in 27.8 % (32/115) and 42.6 % (49/115) cases, respectively, meanwhile in VS operated via blind sac technique, good short-term (p = 0.048) and long-term (p = 0.044) facial nerve function was reached in 44.0 % (22/50) and 60.0 % (30/50) cases, respectively. Postoperative facial nerve function was proved to be better in modified ETLA group. CSF leakage occurred in 16 (4.2 %) patients via classic ETLA. In 115 cases of large VS (>3 cm), postoperative CSF leakage occurred in 10 (8.7 %) patients. Whereas in 50 cases via blind sac technique, none developed CSF leakage (p = 0.03). The incidence of CSF leakage was lower in modified ETLA group. Our refinements to classic ETLA by changing the temporal bone resection range provide a wide surgical field, well prevention of CSF leakage and preservation of facial nerve function in large VS.

Surgical treatment of acoustic neuroma: Outcomes and indications.

AIM: Surgery for acoustic neuroma has developed over the years with a gradual improvement in outcome. The goal of surgery should be cure of the disease and a low morbidity, preserving facial nerve function - and hearing, too, whenever feasible (i.e. in small tumors). The most appropriate approach must be decided case by case. BACKGROUND: Results of microsurgery remain heterogeneous, however, probably due to the different amount of experience gained at different centers. MATERIALS AND METHODS: Surgical series reported in the recent literature (2012-2015) were critically reviewed, along with some older papers with particularly representative series. RESULTS AND CONCLUSION: Considering patients' age, surgical morbidity of different approaches, tumor size and hearing, some principles can be identified on which to base surgical indications with a view to achieving the goals of curing the disease with a low morbidity, preserving facial nerve function and hearing, too, whenever feasible (i.e. in patients with small tumors). Different therapeutic approaches are discussed.

Surgical results for one-stage VII/VIII schwannoma resection and hemihypoglossal-facial neurorrhaphy.

BACKGROUND: This retrospective study evaluated the outcomes of patients undergoing one-stage resection of VII/VIII schwannomas and hemihypoglossal-facial neurorrhaphy via the translabyrinthine approach (TLA). METHODS: The study encompassed ten consecutive patients with unilateral hearing loss (six women, four men, mean age: 49.5 ± 12.1 years) who underwent surgery. The cohort included two patients with vestibular schwannomas (VSs), four with facial nerve schwannomas (FNSs) (two originating from the geniculate ganglion of the facial nerve and two from the cerebellopontine angle), one with VS regrowth, and three with residual VSs. Preoperative facial nerve function, assessed using the House-Brackmann (HB) scale, was Grade V in one and Grade VI in nine patients. The mean preoperative duration of facial paralysis was 7.5 ± 6.9 months. RESULTS: All patients underwent gross total resection. Postoperatively, one patient experienced cerebrospinal fluid leaks, which were successfully managed with lumbar drains and surgical revisions. At follow-up, facial nerve function improved in all patients: HB Grade V to III in one, HB Grade VI to III in one, HB Grade VI to IV in seven, and Grade VI to V in one. No tumor recurrence was observed during the follow-up period (mean duration: 16.6 ± 9.3 months), and no patient had hemilingual atrophy. CONCLUSION: The TLA for one-stage resection of VII/VIII schwannomas and facial nerve reconstruction is effective in treating both regrowth and residual VSs and FNSs in the cerebellopontine angle or petrosal bone in patients with severe preoperative facial palsy. This technique facilitates simultaneous tumor removal and nerve anastomosis, thereby reducing the need for multiple surgical interventions in patients with hearing loss and compromised facial nerve function.

Development of a feline model for preclinical research of a new translabyrinthine auditory nerve implant.

Cochlear implants are among the most successful neural prosthetic devices to date but exhibit poor frequency selectivity and the inability to consistently activate apical (low frequency) spiral ganglion neurons. These issues can limit hearing performance in many cochlear implant patients, especially for understanding speech in noisy environments and in perceiving or appreciating more complex inputs such as music and multiple talkers. For cochlear implants, electrical current must pass through the bony wall of the cochlea, leading to widespread activation of auditory nerve fibers. Cochlear implants also cannot be implanted in some individuals with an obstruction or severe malformations of the cochlea. Alternatively, intraneural stimulation delivered via an auditory nerve implant could provide direct contact with neural fibers and thus reduce unwanted current spread. More confined current during stimulation can increase selectivity of frequency fiber activation. Furthermore, devices such as the Utah Slanted Electrode Array can provide access to the full cross section of the auditory nerve, including low frequency fibers that are difficult to reach using a cochlear implant. However, further scientific and preclinical research of these Utah Slanted Electrode Array devices is limited by the lack of a chronic large animal model for the auditory nerve implant, especially one that leverages an appropriate surgical approach relevant for human translation. This paper presents a newly developed transbullar translabyrinthine surgical approach for implanting the auditory nerve implant into the cat auditory nerve. In our first of a series of studies, we demonstrate a surgical approach in non-recovery experiments that enables implantation of the auditory nerve implant into the auditory nerve, without damaging the device and enabling effective activation of the auditory nerve fibers, as measured by electrode impedances and electrically evoked auditory brainstem responses. These positive results motivate performing future chronic cat studies to assess the long-term stability and function of these auditory nerve implant devices, as well as development of novel stimulation strategies that can be translated to human patients.

Translabyrinthine Approach for Sporadic Vestibular Schwannoma: Patient Selection, Technical Pearls, and Patient Outcomes.

Herein we briefly describe the translabyrinthine approach to vestibular schwannoma resection as well as a focused literature review as to the best candidates, technical recommendations, and key outcomes with respect to other approaches.

Two-Stage Surgical Management for Acutely Presented Large Vestibular Schwannomas: Report of Two Cases.

The surgical management of vestibular schwannomas should be based on their presentation, neuro-imaging findings, surgeons' expertise, and logistics. Multi-stage surgery can be beneficial for large-sized lesions with acute presentations. Herein, we highlighted the indications for two cases managed initially through the retrosigmoid and, subsequently, translabyrinthine approaches. The first case presented with acute balance and gait issues and a long history of hearing loss and blurred vision. Neuroimaging findings revealed a cerebellopontine angle lesion, resembling a vestibular schwannoma, with significant brainstem compression and hydrocephalus. Due to the rapidly deteriorating clinical status and large-sized tumor, we first proceeded with urgent decompression via a retrosigmoid approach, followed by gross total resection via a translabyrinthine approach two weeks later. The second case presented with gradually worsening dizziness and hemifacial numbness accompanied by acute onset severe headaches and hearing loss. Neuroimaging findings showed a large cerebellopontine angle lesion suggestive of a vestibular schwannoma with acute intratumoral hemorrhage. Given the acute clinical deterioration and large size of the tumor, we performed urgent decompression with a retrosigmoid approach followed by gross total resection through a translabyrinthine approach a week later. Post-surgery, both patients showed excellent recovery. When managing acutely presented large-sized vestibular schwannomas, immediate surgical decompression is vital to avoid permanent neurological deficits.

A Rare Case of Pleomorphic Adenoma in the Internal Auditory Canal.

Pleomorphic adenoma is a common tumor of the salivary gland tumor, but it is rare in the ear. To the authors' knowledge, this patient is the first reported case of pleomorphic adenoma arising in the internal auditory canal. There have been few documents reporting the manifestations and the therapy strategy of this disease. This study clearly demonstrated the experience in treating pleomorphic adenoma, including the characteristics of the clinical manifestation, the key procedures of surgery, and key points of the diagnosis. The translabyrinthine approach under the microscope performed to remove this tumor is a good option for resecting this type of tumor.

A case of facial nerve palsy caused by severe head injury treated by translabyrinthine approach.

Background: Several treatments for traumatic facial paralysis have been reported, but the role of surgery is still controversial. Case Description: A 57-year-old man was admitted to our hospital with head trauma due to a fall injury. A total body computed tomography (CT) scan showed a left frontal acute epidural hematoma associated with a left optic canal and petrous bone fractures with the disappearance of the light reflex. Hematoma removal and optic nerve decompression were performed immediately. The initial treatment was successful with complete recovery of consciousness and vision. The facial nerve paralysis (House and Brackmann scale grade 6) did not improve after medical therapy, and thus, surgical reconstruction was performed 3 months after the injury. The left hearing was lost entirely, and the facial nerve was surgically exposed from the internal auditory canal to the stylomastoid foramen through the translabyrinthine approach. The facial nerve's fracture line and damaged portion were recognized intraoperatively near the geniculate ganglion. The facial nerve was reconstructed using a greater auricular nerve graft. Functional recovery was observed at the 6-months follow-up (House and Brackmann grade 4), with significant recovery in the orbicularis oris muscle. Conclusion: Interventions tend to be delayed, but it is possible to select a treatment method of the translabyrinthine approach.

Middle Ear Cholesteatoma and Vestibular Schwannoma Resection Followed by Cochlear Implant: Surgical Challenges and Audiological Outcomes.

(1) Background: The occurrence of vestibular schwannoma (VS) associated with cholesteatoma is rare. A hearing impairment is one of the most significant issues in such cases. Moreover, the presence of middle and inner ear pathologies combined may represent a surgical challenge. No studies have described a combined surgical approach for these coexisting conditions (VS and cholesteatoma), nor the hearing rehabilitation outcomes of using cochlear implants for these patients. (2) Case Report: This paper is on a female patient who underwent simultaneous surgical treatments for VS and middle ear cholesteatoma in the right ear followed by a cochlear implant, describing the technique and the audiological results. (3) Conclusions: The surgical approach was successful and enabled the resection of lesions with the auditory nerve and cochlea preservation. Cochlear implantation in the right ear showed positive postoperative results, with an improvement in the results with the CI in silent and noisy environments.

Microsurgical Gross Total Resection of an Intracanalicular-Cisternal (Koos-4) Vestibular Schwannoma via a Retrosigmoid Approach with Intraoperative Endoscopic Assistance.

We present the case of a 23-year-old female with a history of progressive hearing loss in the left ear, dizziness, and vertigo. Magnetic resonance imaging demonstrated a left mass extending from the internal auditory canal into the cerebellopontine angle (Koos-4).1 A retrosigmoid approach assisted with a microinspection tool was chosen.2-5 Microsurgical near total resection was achieved. The patient presented a postoperative facial deficit (House-Brackman grade 2 postoperative), with complete resolution after 2 months. Video 1 highlights the critical steps of the retrosigmoid approach and the benefit of using the microinspection tool for vestibular schwannoma resection.

Operative Technique: Angiomatoid Fibrous Histiocytoma-Unique Case and Management.

Objective We describe the first jugular foramen angiomatoid fibrous histiocytoma (AFH) case and the first treatment with preoperative endovascular embolization. AFH is a rare intracranial neoplasm, primarily found in pediatric patient extremities. With an increase in AFH awareness and a well-described genetic profile, intracranial prevalence has also subsequently increased. Study Design We compare this case to previously reported cases using PubMed/Medline literature search, which was performed using the algorithm ["intracranial" AND "angiomatoid fibrous histiocytoma"] through December 2020 (23 manuscripts with 46 unique cases). Patient An 8-year-old female presented with failure to thrive and right-sided hearing loss. Work-up revealed an absence of right-sided serviceable hearing and a large jugular foramen mass. Angiogram revealed primary arterial supply from the posterior branch of the ascending pharyngeal artery, which was preoperatively embolized. Intervention Gross total resection was performed via a translabyrinthine approach. Conclusion The case presented is unique; the first reported AFH at the jugular foramen and the first reported case utilizing preoperative embolization. Preoperative embolization is a relatively safe technique that can improve the surgeon's ability to perform a maximally safe resection, which may decrease the need for adjuvant radiation in rare skull base tumors in young patients.