Utility of sodium fluorescein in recurrent cervical vagus schwannoma surgery.

Background: Cervical schwannoma is a rare neoplasm that usually occurs like a nondolent lateral neck mass but when growing and symptomatic requires radical excision. Sodium fluorescein (SF) is a dye that is uptake by schwannomas, which makes it amenable for its use in the resection of difficult or recurrent cases. Methods: We describe the case of a patient presenting with a recurrence of a vagus nerve schwannoma in the cervical region and the step-by-step technique for its complete microsurgical exeresis helped by the use of SF dye. Results: We achieved a complete microsurgical exeresis, despite the presence of exuberant perilesional fibrosis, by exploiting the ability of SF to stain the schwannoma and nearby tissues. That happens due to altered vascular permeability, allowing us to better differentiate the lesion boundaries and reactive scar tissue under microscope visualization (YELLOW 560 nm filter). Conclusion: Recurrent cervical schwannoma might represent a surgical challenge due to its relation to the nerve, main cervical vessels, and the scar tissue encompassing the lesion. Although SF can cross both blood-brain and blood-tumor barriers, the impregnation of neoplastic tissue is still greater than that of nonneoplastic peripheric tissues. Such behavior may facilitate a safer removal of this kind of lesion while respecting contiguous anatomical structures.

Microsurgery of Koos I-II vestibular schwannomas: a case series of 100 consecutive patients.

BACKGROUND: Treatment of small vestibular schwannomas (VS) depends on size, growth pattern, age, symptoms, co-morbidities. Watchful waiting, stereotactic radiosurgery and microsurgery are three valid options of treatment. METHODS: We reviewed clinical sheets, surgical data and results of 100 consecutive patients with Koos Grade I-II VS, operated at our department via a retrosigmoid microsurgical approach between September 2010 and July 2021. Extent of resection was assessed as total, near-total or subtotal. The course of facial nerve (FN) around the tumor was classified as anterior (A), anterior-inferior (AI), anterior-superior (AS) and dorsal (D). FN function was assessed according to House-Brackmann (HB) Scale and hearing level according to AAO-HNS Classification. RESULTS: Mean tumor size was 1.52 cm. FN course was mainly AS (46.0%) in the overall cohort; in Koos I VS, FN was AS in 83.3%. Postoperative FN function was HB I in 97% and HB II in 3% of cases. Hearing preservation (AAO-HNS class A-B) was possible in 63.2% of procedures. Total/near-total removal was achieved in 98%. Postoperative mortality was zero. Transient complications were observed in 8% of patients; permanent complications never occurred. Tumor remnant progression was observed in one case, 5 years after subtotal removal. CONCLUSIONS: Microsurgery represents a valid option for management of VS, including Koos I-II grades, with an acceptable complication rate. In particular, in small VS long-term FN facial outcome, HP and total/near-total removal rate are favorable.

Hypervascularized Large Vestibular Schwannomas: Single-Center Experience in a Series of Forty Cases.

Background: Vestibular schwannomas (VS) are usually hypovascularized benign tumors. Large VS (Koos grade IV) with unusual vascular architecture are defined as hypervascular (HVVS); the excessive bleeding during microsurgery has a negative impact on results. Methods: Forty consecutive patients were operated on for HVVS (group A). A tendency to bleed and adherence of capsule to nervous structures were evaluated by reviewing intraoperative video records. The cisternal facial nerve (FN) position was reported. Microsurgical removal was classified as total, near-total, subtotal, or partial and the MIB-1 index was evaluated in all. FN results were classified according to the House-Brackmann scale. Results: Results of Group A were compared with those of 45 patients operated on for large low-bleeding VS (group B). Mean tumor diameter was 3.81 cm in group A and 3.58 cm in group B; the mean age was 42.4 and 56.3 years, respectively. The mean American Society of Anesthesiologists Physical Status Scale class of group A was 1.67 versus 2.31 of group B (P < 0.01). Total or near-total resection was accomplished in 76.5% of group A versus 73.3% of group B. Tight capsule adhesion was observed in 67.5% of group A versus 57.8% of group B. Mean MIB-1 was 1.25% and 1.08%, respectively.FN anatomic preservation was possible in 84.6% of group A versus 95.5% of group B; 67.5% of group A had HB grade I or II FN outcome versus 93.3% of group B (P < 0.001). In group A, 8 patients (20.0%) experienced transient postoperative complications versus 4.4% of group B. Recurrence/regrowth was observed in 4 patients in group A versus 1 in group B. Conclusions: Intraoperative video for classification of HVVS was used. Microsurgery of large HVVS was associated with higher (usually transient) complications and recurrence/regrowth rates and poorer FN outcome, especially in patients with tight capsule adhesion.

Surgical management of spinal schwannomas arising from the first and second cervical roots: Results of a cumulative case series.

Objective: Schwannomas of the first and second nerve roots are rare neurosurgical entities, harboring specific surgical features that make surgical resection particularly challenging and deserve specifics dissertations. This study is a retrospectively analysis of 14 patients operated in two different neurosurgical centers: the San Filippo Neri Hospital of Rome and the Federal Centre of Neurosurgery of Tjumen. Materials and Methods: In the last 6 years, 14 patients underwent neurosurgical resection of high cervical (C1-C2) schwannomas, in two different neurosurgical centers. Patients data regarding clinical presentation, radiological findings, and surgical results were retrospectively analyzed. Results: The mean age was 50 years (range 13-74), the follow-up mean duration was 30 ± 8.5 (range 24-72 months), and there was no significant differences among different tumor locations (intradural, extradural, and dumbbell). Surgical results were excellent: gross total resection was achieved in all cases and there were no intraoperative complications or postoperative mortality. All patients presented postoperative clinical improvement except one who remained stable. Karnofsky performance status, at the last follow-up, confirmed a global clinical improvement. No vertebral artery (VA) injury neither spinal instability occurred; nerve root sacrifice was reported in one case. Conclusions: Neurosurgical treatment of C1-C2 schwannomas is associated with good outcomes in terms of extent of resection and neurological function. In particular, dumbbell shape and VA involvement do not represent limitations to achieve complete tumor resection and good clinical outcome. In conclusion, microsurgery represents the treatment of choice for C1-C2 schwannomas.

Inflammatory Pseudotumor Simulating a Jugular Foramen Meningioma: Case Report, Technical Video, and Literature Review.

Inflammatory pseudotumor (IP) is a nonneoplastic, reactive inflammatory process, of unknown etiology, characterized by a proliferation of connective tissue with an inflammatory infiltrate, most commonly involving the lungs and orbits. Primary intracranial IP is an extremely rare entity often arising from the meningeal structures of the skull base. We reported an extremely rare case of a primary intracranial IP located in the cerebellopontine angle, mimicking a jugular foramen meningioma. We further illustrated our microsurgical technique through a surgical video and performed a review of the pertinent scientific literature. The patient underwent gross total microsurgical resection of the tumor mass through a left retrosigmoid approach. Intraoperative neuromonitoring of the VII-VIII cranial nerve complex and lower cranial nerve was performed, and thulium laser fibers were used as a tool for tumor debulking. Postoperatively, the patient's neurologic symptoms recovered. Histopathologic studies showed dense infiltrate of T- and B-cell lymphocytes and epithelioid granulomas, compatible with the diagnosis of IP. Postoperatively, magnetic resonance imaging scans showed complete tumor resection. The patient underwent a 3-month oral corticosteroid therapy showing no signs of recurrence at the radiologic follow-up. Primary intracranial IPs are rare pathologic entities that can mimic extraaxial tumors and should be taken into consideration as a potential differential diagnosis. Complete microsurgical resection in combination with other treatments (steroids therapy, radiotherapy) is the most common treatment of choice and is associated with good outcomes and low rates of recurrence.

Safeness and efficacy of 2-µm handheld thulium laser during microsurgical resection of supratentorial and infratentorial meningiomas: Experience of a single center.

Aims: We performed a retrospective nonrandomized study to analyze the results of a microsurgery of intracranial meningiomas using 2-µm thulium flexible handheld laser fiber (Revolix jr). Methods: From February 2014 to December 2021, 75 nonconsecutive patients suffering from intracranial meningiomas, admitted in our department, have been operated on with microsurgical technique assisted by 2-µm thulium flexible handheld laser. We have reviewed demographic and clinical data to evaluate safety and efficacy of the technique. Results: There were no complications related to the use of the 2-µm thulium laser. We operated on a high percentage of cranial base and tentorial and posterior fossa meningioma in our series. The neurological outcome and degree of resection did not differ from previous series. The neurosurgical team found the laser easy to use and practical for avoiding bleeding and traction. Conclusion: The use of 2-µm thulium fiber handheld flexible laser in microsurgery of intracranial meningiomas seems to be safe and to facilitate tumor resection, especially in "difficult" conditions (e.g., deep seated, highly vascularized, and hard tumors). Even if in this limited retrospective trial the good functional outcome following conventional microsurgery had not further improved, nor the surgical time was reduced by laser, focusing its use on "difficult" (large and vascularized) cases may lead to different results in the future.

Microsurgical treatment of symptomatic vestibular schwannomas in patients under 40: different results before and after age of 30.

In 10-15% of cases of vestibular schwannoma (VS), age at diagnosis is 40 years or less. Little is known about the differences in natural history, surgical findings, and postoperative outcomes of such younger patients as compared to those of greater age. To analyze clinical and surgical and imaging data of a consecutive series of n = 50 patients with unilateral sporadic VS, aged 40 years or younger - separated in a very young group (15-30 years) and a moderately young group (31-40 years). Retrospective case series. Fifty consecutive patients under 40 years of age underwent microsurgical resection of unilateral sporadic VS via the retrosigmoid approach. The study cohort was subdivided into two groups according to the age range: group A, age range 15-30 years (n = 23 patients), and group B, age range 31-40 years (n = 27 patients). The adherence of VS capsule to surrounding nervous structures and the tendency of the tumors to bleed were evaluated by reviewing video records; the course of the FN in relation to the tumor's surface was assessed in each case. Microsurgical removal of tumor was classified as total (T), near total (residual tumor volume < 5%), subtotal (residual tumor volume 5-10%), or partial (residual tumor volume > 10%). Mean tumor size of entire cohort was 2.53 (range: 0.6-5.8) cm: 2.84 cm in group A and 2.36 cm in group B (p = NS). Facial nerve course and position within the cerebellopontine angle did not differ significantly between the two groups. At 6-month follow-up, FN functional outcome was HBI-II in 69.5% in group A, versus 96.3% in group B (p < .001). Hearing preservation was achieved in 60.0% of patients of group A and in 58.3% of group B (p = NS). Total and near-total resection was feasible in 95.6% of cases of group A and in 88.9% of group B (p = NS). Tumor capsule was tightly adherent to nervous structures in 69.6% patients of group A and in 22.2% of group B (p < .05). Significant bleeding was encountered in 56.5% of group A tumors, and in 29.6% of group B tumors (p < .01). Microsurgery of VS in patients aged 40 or less is associated with good functional results, and with high rates of total and near total tumor removal. Patients < 30 years of age have more adherent tumor capsules. Furthermore, their tumors exhibit a tendency to larger sizes, to hypervascularization, to profuse intraoperative bleeding and they present worse long-term functional FN results when compared to patients in their fourth decade of life. Our limited experience seems to suggest that a near total resection in very young VS patients with large tumors should be preferred in adherent and hypervascularized cases, in order to maximize resection and preserve function.

Single-Level Cervical Arthroplasty with a Keel-less Prosthesis: Results in a Series of 35 Patients Operated on for Soft Disk Herniation with a Minimum of 3 Years of Follow-Up.

BACKGROUND: Cervical arthroplasty with artificial cervical disks has gained popularity as an alternative to anterior discectomy and fusion. The main advantages of disk arthroplasty include maintenance of the range of movement, restitution of disk height and spinal alignment, and reduction of adjacent segment degeneration (ASD). In this article, we aimed to assess the outcomes of the use of a keel-less prosthesis. MATERIAL AND METHODS: We included all the patients who underwent single-level cervical arthroplasties with the Discocerv Cervidisc Evolution for "soft" disk herniation. Clinical assessment included Neck Disability Index (NDI) and visual analog scale (VAS) for neck and arm pain. Radiologic studies investigated the occurrence of ASD and system failure or subsidence. The reoperation rate was also recorded. RESULTS: The study included 35 patients (14 men and 21 women; mean age: 42.5 years; mean follow-up: 57.8 months). There was a significant decrease in VAS neck and VAS arm scores, which went from 7.2 and 6.9 preoperatively to 2.2 and 1.7 postoperatively, 2.2 and 1.6 at 6 months, 2.0 and 1.8 at 1 year, and 2.1 and 1.3 at the last follow-up, respectively. The mean NDI score was 58.0 preoperatively, 19.4 postoperatively, 17.0 at 6 months, 16.1 at 1 year, and 16.2 at the last follow-up. Radiologic studies revealed a preserved range of motion in 33 of 35 patients. No ASD occurred and no reoperation was required. CONCLUSIONS: Cervical disk arthroplasty with a keel-less prosthesis can be a safe and effective alternative to fusion for degenerative disk disease in selected patients, with a possible reduction of ASD.

"Limited" Extreme Lateral Infrajugular Transcondylar-Transtubercular Exposure (ELITE) for the Microsurgical Management of C1-C2 Schwannoma: Operative Video.

The extreme lateral infrajugular transcondylar-transtubercular exposure (ELITE) is a surgical approach developed in the late 1980s by Prof. T. Fukushima and represents the dorsolateral inferior skull base procedure of choice to approach lesion located ventrolaterally at the level of the craniocervical junction (CCJ). This approach consist in a suboccipital craniotomy/craniectomy with partial condylectomy and jugular tubercule drilling that can be extended providing for subtotal condylectomy and vertebral artery transposition. The "limited" variation of the ELITE approach consist in a lateral suboccipital craniectomy opening the foramen magnum and removal of at least half of the posterior arch of the atlas without condyle drilling. This surgical technique was recently demonstrated to be particularly suitable for the surgical management of spinal tumor located ventrolaterally in the upper cervical spine. This operative video illustrates step-by-step the surgical technique adopted for the microsurgical resection of a C1-C2 intradural schwannoma located antero-laterally (Video 1). ELITE approach offers a wide and adequate exposure and access to the CCJ, allowing direct visualization and access to the tumor with minimal neural manipulations, early detection of the vertebral artery and, for tumor located at C1-C2 level, without drilling the occipital condyle. In our experience, ELITE procedure is the preferred surgical approach for resection of tumors located ventrally or ventrolaterally to the first 2 cervical levels.

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.

Koos grade IV vestibular schwannomas (VS) (maximum diameter > 3 cm) compress the brainstem and displace the fourth ventricle. Microsurgical resection with attention to the right balance between preservation of function and maximal tumor removal is the treatment of choice. 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 the 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%). Maximal mean tumor diameter was 3,97 cm (SD ± 1,13; range 3,1-5,8 cm). 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 (56,7%) patients had a normal postoperative FN outcome (HBI), 9 (15,0%) were HBII, 8 (13,3%) HBIII, and 9 (15,0%) HBIV. The 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. 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.

Flexible endoscopic assistance in the surgical management of vestibular schwannomas.

Endoscopic-assisted techniques have extensively been applied to vestibular schwannoma (VS) surgery allowing to increase the extent of resection, minimize complications, and preserve facial nerve and auditory functions. In this paper, we retrospectively analyze the effectiveness of flexible endoscope in the endoscopic-assisted retrosigmoid approach for the surgical management of VS of various sizes. The authors conducted a retrospective analysis on 32 patients who underwent combined microscopic and flexible endoscopic resection of VS of various sizes over a period of 16 months. Flexible endoscopic-assisted retrosigmoid approach was performed in all cases, and in 6 cases, flexible and rigid endoscopic control were used in combination to evaluate the differences between the two surgical instruments. The surgical results were additionally compared with a previous case series of 141 patients operated for VS of various sizes without endoscopic assistance. Gross-total resection was achieved in 84% of the cases and near-total resection was accomplished in the rest of them. Excellent or good facial nerve function was observed in all except one case with a preoperative severe facial palsy. Hearing preservation surgery (HPS) was attempted in 11 cases and accomplished in 9 (81.8%). A tumor remnant was endoscopically identified in the fundus of the IAC in all cases (100%). Endoscopic assistance increased the rate of total removal and no intrameatal residual tumor was seen at radiological follow-up. Comparative analysis with a surgical cohort of patients operated with the sole microsurgical technique showed a significative association between endoscopic assistance and intracanalicular extent of resection. Combined microsurgical and flexible endoscopic assistance provides remarkable advantages in the pursuit of maximal safe resection of VS and preservation of facial nerve and auditory functions, minimizing the risk of post-operative complications.

Postoperative Functional Preservation of Facial Nerve in Cystic Vestibular Schwannoma.

OBJECTIVE: To retrospectively analyze clinical and surgical data of a consecutive series of 26 patients with unilateral cystic vestibular schwannomas. METHODS: Tumors were classified as type A (central cyst) and type B (peripheral cyst) and as small (tumor diameter <3 cm) and large (tumor diameter >3 cm). All patients underwent microsurgical removal via retrosigmoid approach. The course of the facial nerve (FN) was classified as anterior, anterior-inferior, anterior-superior, and dorsal to the tumor's surface. RESULTS: Mean patient age was 53.5 years. Mean tumor size was 3.2 cm. There were 22 cases classified as type A and only 4 as type B. Total or near-total resection (>95%) was achieved in 16 cases (61.5%), subtotal removal (90%-95%) was achieved in 9 cases (34.6%), and partial removal (<90%) was achieved in 1 case (3.9%). Position pattern of FN was anterior-inferior in 10 cases (38.4%), anterior-superior in 10 cases (38.4%), anterior in 23.2% of 6 cases. At hospital discharge, FN function was House-Brackmann grade I-V in 9 (36%), 10 (38%), 3 (12%), 3 (12%), and 1 (4%) patients; at final follow-up, House-Brackmann grades I, II, III, and IV accounted for 18 (72%), 6 (24%), 1, and 1 cases. During follow-up ranging from 6 months to 10 years, reoperation for growing of residue was never necessary. CONCLUSIONS: According to the literature and the results of our series, microneurosurgery of cystic vestibular schwannomas is associated with good outcomes in terms of extent of resection and FN function. In particular, long-term FN function is much more satisfactory than short-term function. In most cases, microsurgery represents the treatment of choice of cystic vestibular schwannomas.

Extended Middle Cranial Fossa Approach for Lesions Invading Infratemporal Fossa: Anatomic Study and Clinical Application.

Skull base tumors arising from the middle cranial fossa and invading of the infratemporal fossa (ITF) and middle cranial fossa are challenging for neurosurgeons, because of complex anatomy and critical neurovascular structure involvement. The first pioneering ITF approaches resulted in invasive procedures and carried a high rate of surgical morbidity. However, the acquisition of deep anatomical knowledge, and the development operative skills and reconstruction techniques allowed surgeons to achieve total or near total resection of many ITF lesions with a low morbidity rate. In Video 1 we illustrate our technique for the anterior ITF approach for the surgical treatment of a middle cranial fossa meningioma invading the ITF. This surgical video describes the anterior ITF approach in 2 steps. First, a standard extradural middle fossa approach subtemporal approach is performed on a cadaveric specimen, illustrating the anterior extension to the cavernous sinus. Second, the anterior ITF approach is performed for the surgical treatment of a temporal lobe meningioma with extension to the anterior ITF. This technique provides a minimally invasive approach for treating middle fossa lesions with anterior ITF extension.

Microvascular decompression for typical trigeminal neuralgia: Personal experience with intraoperative neuromonitoring with level-specific-CE-Chirp® brainstem auditory evoked potentials in preventing possible hearing loss.

BACKGROUND: Permanent hearing loss after posterior fossa microvascular decompression (MVD) for typical trigeminal neuralgia (TTN) is one of the possible complications of this procedure. Intraoperative brainstem auditory evoked potentials (BAEPs) are used for monitoring the function of cochlear nerve during cerebellopontine angle (CPA) microsurgery. Level-specific (LS)-CE-Chirp® BAEPs are the most recent evolution of classical click BAEP, performed both in clinical studies and during intraoperative neuromonitoring (IONM) of acoustic pathways during several neurosurgical procedures. METHODS: Since February 2016, we routinely use LS-CE-Chirp® BAEPs for monitoring the function of cochlear nerve during CPA surgery, including MVD for trigeminal neuralgia. From September 2011 to December 2018, 71 MVDs for TTN were performed in our department, 47 without IONM of acoustic pathways (Group A), and, from February 2016, 24 with LS-CE-Chirp BAEP (Group B). RESULTS: Two patients of Group A developed a permanent ipsilateral anacusia after MVD. In Group B, we did not observe any permanent acoustic deficit after surgery. In one case of Group B, during arachnoid dissection, intraoperative LS-CE-Chirp BAEP showed a temporary lag of V wave, resolved in 5 min after application of intracisternal diluted papaverine (0.3% solution without excipients). CONCLUSION: MVD is widely considered a definitive surgical procedure in the management of TTN. Even though posterior fossa MVD is a safe procedure, serious complications might occur. In particular, the use of IONM of acoustic pathways during MVD for TTN might contribute to prevention of postoperative hearing loss.

Typical Trigeminal Neuralgia: Comparison of Results between Patients Older and Younger than 65 Years Operated on with Microvascular Decompression by Retrosigmoid Approach.

OBJECTIVE: The incidence of typical trigeminal neuralgia (TN) increases with age, and neurologists and neurosurgeons frequently observe patients with this disorder at age 65 years or older. Microvascular decompression (MVD) of the trigeminal root entry zone in the posterior cranial fossa represents the etiological treatment of typical TN with the highest efficacy and durability of all treatments. This procedure is associated with possible risks (cerebellar hematoma, cranial nerve injury, stroke, and death) not seen with the alternative ablative procedures. Thus the safety of MVD in the elderly remains a topic of discussion. This study was conducted to determine whether MVD is a safe and effective treatment in older patients with TN compared with younger patients. METHODS: In this retrospective study, 28 patients older than 65 years (elderly cohort: mean age 70.9 ± 3.6 years) and 38 patients < 65 years (younger cohort: mean age 51.7 ± 6.3 years) underwent MVD via the keyhole retrosigmoid approach for type 1 TN (typical) or type 2a TN (typically chronic) from November 2011 to November 2017. A 75-year-old patient and three nonelderly patients with type 2b TN (atypical) were excluded. Elderly and younger cohorts were compared for outcome and complications. RESULTS: At a mean follow-up 26.0 ± 5.5 months, 25 patients of the elderly cohort (89.3%) reported a good outcome without the need for any medication for pain versus 34 (89.5%) of the younger cohort. Twenty-three elderly patients with type 1 TN were compared with 30 younger patients with type 1 TN, and no significant difference in outcomes was found (p > 0.05). Five elderly patients with type 2a TN were compared with eight younger patients with type 2a TN, and no significant difference in outcomes was noted (p > 0.05). There was one case of cerebrospinal fluid leak and one of a cerebellar hematoma, both in the younger cohort. Mortality was zero in both cohorts. CONCLUSIONS: On the basis of our experience and the international literature, age itself does not seem to represent a major contraindication of MVD for TN.

Negative influence of preoperative tinnitus on hearing preservation in vestibular schwannoma surgery.

BACKGROUND: Goals of vestibular schwannoma (VS) microsurgery are maximal resection, facial nerve (FN) preservation and in selected cases, hearing preservation (HP). Postoperative HP rates are related to clinical and radiographic factors: size of tumor, preoperative hearing, hypertension, diabetes, and presence or absence of preoperative tinnitus. In this retrospective review we evaluated the influence of preoperative tinnitus on HP after VS surgery in patients with preoperative socially useful hearing (SUH). METHODS: Twenty-five patients with SUH underwent VS micro neurosurgery by retrosigmoid (RS) approach. Selection criteria were pure tone audiogram ≤50dB loss and speech discrimination score >50% (50/50 criterion, AAO-HNS class A-B). In relation to maximum diameter, we identified two size-groups: 1) group A ≤2cm (13 cases); 2) group B >2cm (12 cases). HP attempt was assisted by intraoperative ABR evoked by LS CE-Chirp® (Interacustics, Middelfart, Denmark) acoustic stimuli. RESULTS: Mean age was 44.3 years (20-64); average maximum diameter 2,0cm (0,8-4). Preoperative tinnitus was present in 10 patients (40%): all of them had a Class B-hearing. Total and nearly-total (>95%) resection was possible in all. Mortality and major morbidity were zero. In all, facial nerve (FN) was anatomically and functionally preserved; in 10 an incomplete FN deficit was followed by complete recovery within 2-8 weeks. At a follow-up ranging from 8 to 17 months (average 12.7 months), socially useful hearing (SUH) preservation rate was 52%, with significant differences in relation to size: 61.5% group A and 41.7% group B (P=0.014). Postoperative AAO-HNS C (serviceable) hearing was observed in 36%, deafness in 12%. At last follow-up, among the 10 patients with preoperative tinnitus 6 worsened from Class-B to Class-C, 3 remained in Class-B, and one was deaf. As regards SUH preservation, 3 of 10 patients with preoperative tinnitus and 10 of 15 without it remained in Class-A-B (P=0.006). CONCLUSIONS: Microsurgery represents the first therapeutic option for small growing VS with SUH. Our data confirm that key-hole RS removal of VS with intraoperative LS-CE-Chirp ABR monitoring allows good rate of SUH preservation, especially maximum diameter does not exceed 2cm. Preoperative tinnitus seems to indicate a lower hearing reserve and predicts a lower likelihood of HP.

Hand-Held Thulium Laser Fiber and Ultrasonic Aspirator for Opening the Internal Auditory Canal During Acoustic Neuroma Microneurosurgery: Operative Technique.

Video 1 describes the technique of microsurgery removal of acoustic neuromas (ANs) using new technologies. The Flexible 2µ-Thulium hand-held laser fiber (Revolix jr, LISA laser products, 7 OHG, Berlin, Germany) and Sonopet Ultrasound Aspirator (Stryker, Kalamazoo, Michigan, USA) can be used for a safe and facilitated opening of the internal auditory canal (IAC). We illustrate the operative technique used on a surgical series of 111 cases operated on during the past 8 years, from July 2010 to July 2018. We studied 170 consecutive patients suffering from ANs who were operated on with a microsurgical technique by the key-hole retrosigmoid approach. In 111 cases the "Sonopet" Ultrasound Aspirator was used to open the IAC and a 2µ-Thulium laser fiber was used for cutting the dura mater of the posterior aspect of petrous bone and the IAC, and it was also used to perform tumor capsule incision. From December 2017 we started to check the removal of tumor inside the IAC with a flexible endoscope 4 mm × 65 cm, (Karl Storz GmbH, Tuttlingen, Germany) in order to detect possible tumoral residue and achieve a radical tumor resection in the fundus. The use of these new technologies seems to be safe and subjectively facilitates the opening of the IAC in AN microsurgery.

Hearing preservation after removal of small vestibular schwannomas by retrosigmoid approach: comparison of two different ABR neuromonitoring techniques.

BACKGROUND AND OBJECTIVE: Goals of small vestibular schwannoma (VS) microneurosurgery are as follows: radical resection, facial nerve (FN) preservation, and hearing preservation (HP). Microsurgical advances make HP possible in many patients with preoperative socially useful hearing (SUH). We evaluated postoperative HP in VS with maximum diameter < 2 cm monitored with two different auditory brainstem response (ABR) techniques. MATERIALS AND METHODS: Twenty-eight consecutive non-randomized patients with SUH suffering from small VS underwent keyhole microneurosurgery by retrosigmoid (RS) approach. Selection criteria are as follows: speech discrimination > 50%, pure tone audiogram < 50 dB loss (50/50 criterion; AAO-HNS classes A-B), maximum diameter < 2 cm. HP was attempted with intraoperative ABR, evoked by classical Click (16 cases, group 1) and LS-CE-Chirp® stimulus (12, group 2). RESULTS: Mean age was 47.5 years (16-75); average maximum diameter was 1.35 cm (0.5-1.9 mm). Total and nearly total resection (> 95%) was obtained in all, as confirmed by 24-48-h postoperative enhanced MRI. Mortality and major morbidity were 0. In all cases, FN was preserved; in 3, incomplete deficit recovered within few weeks. Socially useful HP (pre- and postoperatively) was 64.3% (18 of 28): 56.25% group 1 and 75% group 2 (p = NS). Postoperative ipsilateral deafness was observed in 5 cases of group 1 (p < 0.0001). Preoperative tinnitus had negative impact on HP (p < 0.05). CONCLUSIONS: Microsurgery can cure small growing VS with SUH. Our limited experience confirms that keyhole RS removal assisted by intraoperative ABR monitoring leads to valuable rates of SUH. LS-CE-Chirp-evoked ABRs allow a safe, effective, and clear neurophysiological feedback and are faster and, thus, more useful than the Click-ABR.

Anterior Cervical Fusion with Stand-alone Trabecular Metal Cages to Treat Cervical Myelopathy Caused by Degenerative Disk Disease. Observations in 88 Cases with Minimum 12-month Follow-up.

BACKGROUND: Anterior cervical fusion (ACF) with autologous bone was reported > 50 years ago. The continuous development of materials with elastic properties close to that of the cortical bone improves induction of osteogenesis and simplifies the technique of interbody fusion. To determine the safety and efficiency of stand-alone trabecular metal (TM) (or porous tantalum) cages for ACF, we performed a retrospective analysis of 88 consecutive patients with one-level or two-level degenerative disk disease (DDD) causing cervical myelopathy treated by interbody fusion with stand-alone TM cages. MATERIALS AND METHODS: During a 65-month period, 88 consecutive patients had ACF at 105 levels between C3 and C7. All surgeries involved one- or two-segmental DDD producing mild or severe cervical spine myelopathy, in 31 patients (35.2%), associated with unilateral or bilateral radiculopathy. We implanted all disk spaces with unfilled TM trapezoidal cages (Zimmer Biomet Spine, Broomfield, Colorado, United States). RESULTS: At a mean follow-up of 31 months (range: 12-65 months), 95.4% of patients had a good to excellent outcome, with subjective and objective improvement of myelopathy; the result was fair in two and poor in two other patients. Radicular pain and/or any deficits disappeared in 84 patients (95.4%) complaining of preoperative myeloradiculopathy. The fusion rate was 68.2% at 6 months and 100% at 1 year. Device fragmentation was never observed. In two cases, a second operation with removal of TM cages, corpectomy, expansion cages, and plating was necessary. CONCLUSIONS: TM cages appear to be safe and efficient for ACF in DDD patients with myelopathy. To confirm our preliminary impressions, larger studies with long-term follow-up are necessary.

Flexible Endoscopic-Assisted Microsurgical Radical Resection of Intracanalicular Vestibular Schwannomas by a Retrosigmoid Approach: Operative Technique.

The efficacy of endoscopic techniques in the surgical management of intracanalicular vestibular schwannomas (ICVSs) has been underlined in recent studies. An endoscopic- assisted retrosigmoid approach (EARSA) appears to be particularly suitable for achieving complete resection of an ICVS. In this study, we describe the surgical treatment of 3 cases of ICVS with an EARSA, highlighting the advantages and limitations of flexible endoscopy in accomplishing a safe radical resection with hearing preservation. Three patients with an ICVS underwent surgery via a flexible endoscopic-assisted microneurosurgical retrosigmoid approach. Flexible endoscopic assistance allowed the identification of residual tumor located in the most lateral portion of the fundus of the internal auditory canal in all cases. Endoscopic controls and further microsurgical resection were attempted, and complete surgical resection was achieved in all cases without the occurrence of postoperative facial or auditory nerve dysfunction. Flexible endoscopy appears to be particularly useful and safe in the surgical management of ICVS by microneurosurgery via an EARSA.