Cochlear Implant in Patients with Intralabyrinthine Schwannoma without Tumor Removal

(1) Background: Schwannomas of the vestibulocochlear nerve are benign, slow-growing tumors, arising from the Schwann cells. When they originate from neural elements within the vestibule or cochlea, they are defined as intralabyrinthine schwannomas (ILSs). Cochlear implant (CI) has been reported as a feasible solution for hearing restoration in these patients. (2) Methods: Two patients with single-sided deafness (SSD) due to sudden sensorineural hearing loss and ipsilateral tinnitus were the cases. MRI detected an ILS. CI was positioned using a standard round window approach without tumor removal. (3) Results: The hearing threshold was 35 dB in one case and 30 dB in the other 6 mo after activation. Speech audiometry with bisillables in quiet was 21% and 27% at 65 dB, and the tinnitus was completely resolved or reduced. In the localization test, a 25.9° error azimuth was obtained with CI on, compared to 43.2° without CI. The data log reported a daily use of 11 h and 14 h. In order to not decrease the CI’s performance, we decided not to perform tumor exeresis, but only CI surgery to restore functional binaural hearing. (4) Conclusions: These are the sixth and seventh cases in the literature of CI in patients with ILS without any tumor treatment and the first with SSD. Cochlear implant without tumor removal can be a feasible option for restoring binaural hearing without worsening the CI’s performance.

Fluorescence-guided craniotomy of glioblastoma using panitumumab-IRDye800

A contrast-enhancing lesion in the left temporal lobe of a 72-year-old woman was biopsied and diagnosed as glioblastoma. Near-infrared (NIR)–labeled epidermal growth factor receptor (EGFR) antibody, panitumumab-IRDye800, was infused 52 hours before craniotomy without pretreatment. Tumor fluorescence was detected through intact dura, and the visual contrast between disease and peritumoral healthy brain was enhanced after tumor exposure. Residual cancerous tissue was identified with strong fluorescence in resection cavity after en bloc tumor removal. Minimal fluorescence remained in the final wound bed, likely from nonenhancing tumor. Fluorescence was heterogeneously distributed at the infiltrative margin in resected tumor pieces imaged ex vivo. Postoperative MRI confirmed gross-total resection. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21201

Utility of intraoperative real-time near-infrared fluorescence surgery for spinal schwannoma

The authors report the first cases of fluorescence-guided spinal surgery of schwannomas using near-infrared fluorescence imaging with the delayed window indocyanine (ICG) green (DWIG) technique for accurate real-time intraoperative tumor visualization. Patients with intradural spinal schwannomas received 0.5 mg/kg ICG at the beginning of surgery. After 1 hour, using the DWIG technique, near-infrared spectroscopy (NIRS) detected the spinal schwannomas, showing the exact tumor location and boundaries. DWIG with NIRS microscopy confirmed the exact location of spinal schwannomas before and after opening of the dura mater, thereby facilitating successful tumor dissection from the surrounding tissues, tumor resection, and confirmation of tumor removal. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21158

Surgical treatment of glossopharyngeal nerve schwannomas: Results of two-center study (14 patients included) and literature review

Objective: This study is aimed to analyze the outcomes of surgical treatment of glossopharyngeal schwannomas based on pre- and postoperative neurological status assessment. Materials and methods: This paper is a retrospective analysis of examination and surgical treatment of 14 patients who were operated on in two large clinics from 2018 to 2021 inclusive. When analyzing the collected data, gender, age, disease symptoms, tumor size and location, surgical approach, tumor to cranial nerves (CN) ratio, jugular foramen (JF) condition, and tumor removal volume were taken into account. All tumors were divided into groups depending on tumor location relative to the JF. Particular attention was paid to assessing cranial nerves functions. Facial nerve function was assessed as per House-Brackmann Scale (HBS), hearing function as per Gardner-Robertson Scale (GRS). Results: 3 (21.4%) patients had total tumor removal: 2 patients had type A tumors and one had type B tumor. Subtotal resection took place in 7 (50%) cases. In 4 cases, a tumor was partially removed: 3 patients had type D tumors and one had type B tumor. 3 (21.4%) patients had preoperative FN deficit (HBS Grade II) and mild dysfunction. 5 (35.7%) patients had postoperative facial nerve deficit: HBS ІІ, 2; ІІІ, 1; V, 2. Preoperative sensorineural type hearing impairment on the affected side was diagnosed in 13 (92.6%) patients. Before surgery, 6 patients had non-serviceable hearing, which remained at the same level after surgery. None of the patients with grade I or II hearing before surgery had any hearing impairment postoperatively. In 2 (14.3%) cases, hearing improved from grade V to grade III after surgery. 6 (42.9%) patients developed new neurological deficit in the caudal group CN. Postoperative deficit of the caudal group CN occurred in type D tumors in 3 patients, type A tumors 2 patients, and type B tumors one patient. Conclusions: Applying a retrosigmoid approach only makes it possible to achieve total tumor removal in case of type A tumors. To remove other tumor types, it is necessary to select approaches that enable access to the jugular foramen and infratemporal fossa. Intraoperative neurophysiological monitoring is an extremely important tool in glossopharyngeal schwannoma surgery. The most common postoperative complication is a developed or increased deficit of the caudal CN group, which can lead to persistent impairments in the patients’ quality of life. Preservation of the CN VII and VIII function in most cases is a feasible task and shall be ensured as a standard for this pathology.

A Case of Intralabyrinthine Schwannoma Removal and Sequential BonebridgeTM Implantation

Intralabyrinthine schwannoma (ILS) is a rare benign tumor that arises within the membranous labyrinthine. Since hearing loss is inevitable after tumor removal in most cases, an appropriate rehabilitation method should be considered. A 41-year-old male, who was diagnosed with ILS underwent tumor removal via translabyrinthine approach, has subsequently experienced right-side deafness as a result. Seventeen months after the tumor removal, a surgery for hearing rehabilitation was performed. Since cochlear implantation was not doable due to cochlear ossification, an active transcutaneous bone conduction implant (BonebridgeTM , MEDEL) was placed at the sinodural angle. To the best of our knowledge, this is the first report describing hearing rehabilitation with BonebridgeTM implantation after ILS removal.

STMO-5 Utilization of intraoperative multimodal technologies [PET and 5-ALA] for treating glioblastoma

Background: We can improve prognosis of glioblastoma by using positron emission tomography (PET) scans to guide them in removing tumors, and intraoperative magnetic resonance imaging (IoMRI) and 5-aminolevulinic acid (5-ALA) for identifying residual tumors. Tau proteins are reported to accumulate in glioblastomas, so we compared the efficacy of their PET tracer, THK5351, against that of 11C-MET, 18F-FLT, and 18F-FMISO. Methods: Patients (n = 11) underwent scans between February 2020 and July 2021 for glioblastoma resection. Tumor-to-normal tissue accumulation ratio (TNR) and accumulation volumes of 4 PET tracers were evaluated. Following excisions, 5-ALA fluorescent evaluation was classified as strong, vague, or none. Residual tumor volumes and removal rates were determined using T1Gd assessments and PET tracers. IoMRI confirmed presence of residual tumors.Results: THK5351 had a TNR of 5.20, and its accumulated volume was greater than that of other tracers: 1.80 for 11C-MET, 1.72 for 18F-FLT, and 2.82 for 18F-FMISO. 5-ALA fluorescent evaluation was vague (n = 7) or none (n = 4); respective residual tumor volumes (mL) were 2.3 and 0.2 (T1Gd), 5.7 and 0.9 (11C-MET), 5.6 and 0.6 (18F-FLT), 1.3 and 0.4 (18F-FMISO), and 7 and 1.4 (THK5351); respective tumor removal rates (%) were 90.4 and 99.6 (T1Gd), 79.2 and 86.4 (11C-MET), 84.4 and 89.2 (18F-FLT), 94.3 and 94.4 (18F-FMISO), and 72.3 and 83.4 (THK5351). The excised tumor tissue was found in the area where only THK5351 was accumulated.Conclusions: THK5351 accumulated in glioblastomas to a greater degree than that of other tracers, making it useful for discriminating between healthy and malignant tissues.

P.215 Tumor Heatmaps – Feedback Tool for Virtual Reality Neurosurgical Simulation

Background: Performance Heatmaps were designed to visualize the spatial distribution of performance metrics during resection of complex tumors. This novel methodology provides experts (neurosurgeons) and trainees (residents and medical students) with visual feedback on their neurosurgical performance during operative procedures. Methods: Neurosurgeons (NS), senior residents (SR), junior residents (JR) and medical students (MS) performed resection of a complex tumor on the NeuroVR simulation platform. Metrics including time spent, force applied, and tumor volume removed were used to create Performance Heatmaps for each group. Results: During complex operative procedures, greater expertise correlated increased time spent in critical areas (NS = 121.0 s, SR = 103.0 s, JR = 86.1 s, MS = 84.9 s), increased force application (NS = 387 N, SR = 317 N, JR = 340 N, MS = 304 N), and increased tumor removal (NS = .096 cc, SR = .081 cc, JR = .074 cc, MS = .069 cc). Conclusions: Performance Heatmaps further our understanding of neurosurgical expertise by identifying key differences between experts (neurosurgeons) and trainees (residents and medical students). With the adoption of competency-based curricula, intuitive feedback tools will prove essential for trainees seeking surgical mastery.

PARANEOPLASTIC ECZEMA AS AN INITIAL MANIFESTATION OF A RENAL CELL CARCINOMA

Paraneoplastic skin manifestations are well-known accompanying disorders in cases with a malignant tumor. If not treated, some may lead to serious disability. In fact, these conditions disappear after the tumor removal. Plantar hyperkeratosis as the first manifestation of clearcell renal cell carcinoma has not been reported. We present a patient with severe untreatable hyperkeratosis of the soles of the feet. The paraneoplastic etiology of the eczema was suggested, and a left kidney tumor was diagnosed and operated. Rapid improvement of the keratoderma eczema was observed within a week of the tumor removal. The patient has no local and distant metastases. Paraneoplastic skin manifestations as initial syndromes of malignant disease can help in the early diagnosis of cancer at a stage that allows complete cure.

Efficacy of the Suboccipital Paracondylar-Lateral Cervical Approach: The Series of 64 Jugular Foramen Tumors Along With Follow-Up Data

ObjectiveComplete resection of jugular foramen tumors with minimal cranial nerve complications remains challenging even for skilled neurosurgeons. Here, we introduce a modified paracondylar approach, named the suboccipital paracondylar-lateral cervical (SPCLC) approach for this purpose. We also share the follow-up data of our series and discuss the advantages and limitations of this modified paracondylar approach.MethodsWe included 64 patients with jugular foramen tumors who underwent surgery by the same senior neurosurgeon between November 2011 and August 2020. All patients were treated with the SPCLC approach, which aimed for gross total tumor removal in a single-stage operation. The clinical characteristics, including preoperative and postoperative neurological status, the extent of surgical resection, and follow-up data were retrospectively acquired and evaluated.ResultsThere were 48 schwannomas, nine meningiomas, three paragangliomas, one hemangiopericytoma, one chordoma, one endolymphatic sac tumor, and one Langerhans’ cell histiocytosis. The median age of our patients was 43 years (range: 21–77 years). Dysphagia, hoarseness, and tongue deviation were observed in 36, 26, and 28 patients, respectively. Thirty-two patients had hearing function impairments, including hearing loss or tinnitus. Gross total resection was achieved in 59 patients (59/64, 92.2%). Gamma Knife treatment was used to manage residual tumors in five patients. Postoperatively, new-onset or aggravative dysphagia and hoarseness occurred in 26 and 18 cases, respectively. Nine patients developed new-onset facial palsy, and one patient developed new-onset hearing loss. There were no cases of intracranial hematoma, re-operation, tracheostomy, or death. At the latest follow-up, hearing loss and tinnitus had improved in 20 cases (20/32, 62.5%), dysphagia alleviated in 20 cases (20/36, 55.6%), and hoarseness improved in 14 cases (14/26, 53.8%). Over a mean follow-up period of 27.8 ± 19.5 months (range: 3–68 months), tumor recurrence was observed in one patient.ConclusionThe SPCLC approach, modified from the paracondylar approach, and was less invasive, safe, and efficient for certain jugular foramen tumors. Taking advantage of the anatomic understanding, clear operational vision, and appropriate surgical skills, it is possible to achieve gross total tumor removal and the preservation of neurological function.

Endoscopic-assisted microsurgical resection of giant vestibular schwannoma in semi-sitting position

The main objectives of microsurgery for vestibular schwannoma are total tumor removal and preservation of facial and cochlear nerve function. For giant tumors, total tumor removal and facial nerve function preservation are challenging. The semisitting position has some advantages. In this video the authors show the removal of a giant vestibular schwannoma with the patient in a semisitting position. They demonstrate the advantages of the semisitting technique, such as the two-handed microsurgical dissection technique and a clear operative field. Finally, a small residual tumor in the internal auditory canal was removed by endoscopy. The patient’s facial function was House-Brackmann grade I at discharge. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2176