Clinical and Imaging Outcomes After Trigeminal Schwannoma Radiosurgery: Results From a Multicenter, International Cohort Study

BACKGROUND AND OBJECTIVES

An international, multicenter, retrospective study was conducted to evaluate the long-term clinical outcomes and tumor control rates after stereotactic radiosurgery (SRS) for trigeminal schwannoma.

METHODS

Patient data (N = 309) were collected from 14 international radiosurgery centers. The median patient age was 50 years (range 11-87 years). Sixty patients (19%) had prior resections. Abnormal facial sensation was the commonest complaint (49%). The anatomic locations were root (N = 40), ganglion (N = 141), or dumbbell type (N = 128). The median tumor volume was 4 cc (range, 0.2-30.1 cc), and median margin dose was 13 Gy (range, 10-20 Gy). Factors associated with tumor control, symptom improvement, and adverse radiation events were assessed.

RESULTS

The median and mean time to last follow-up was 49 and 65 months (range 6-242 months). Greater than 5-year follow-up was available for 139 patients (45%), and 50 patients (16%) had longer than 10-year follow-up. The overall tumor control rate was 94.5%. Tumors regressed in 146 patients (47.2%), remained unchanged in 128 patients (41.4%), and stabilized after initial expansion in 20 patients (6.5%). Progression-free survival rates at 3 years, 5 years, and 10 years were 91%, 86%, and 80 %. Smaller tumor volume (less than 8 cc) was associated with significantly better progression-free survival ( P = .02). Seventeen patients with sustained growth underwent further intervention at a median of 27 months (3-144 months). Symptom improvement was noted in 140 patients (45%) at a median of 7 months. In multivariate analysis primary, SRS ( P = .003) and smaller tumor volume ( P = .01) were associated with better symptom improvement. Adverse radiation events were documented in 29 patients (9%).

CONCLUSION

SRS was associated with long-term freedom (10 year) from additional management in 80% of patients. SRS proved to be a valuable salvage option after resection. When used as a primary management for smaller volume tumors, both clinical improvement and prevention of new deficits were optimized.

Fully neuroendoscopic resection of cerebellopontine angle tumors through a retrosigmoid approach: a retrospective single-center study

The objective of this study is to preliminarily investigate the surgical safety, efficacy, techniques, and clinical value of fully neuroendoscopic surgery for the resection of cerebellopontine angle (CPA) tumors via a retrosigmoid approach. The clinical data of 47 cerebellopontine angle area (CPA) tumors that were treated by full neuroendoscopic surgery from June 2014 to June 2023 were retrospectively analyzed. The efficacy and advantages of the surgical techniques were evaluated based on indicators such as duration of the surgery, neuroendoscopic techniques, intraoperative integrity of nerves and blood vessels, extent of tumor resection, outcomes or postoperative symptoms, and incidence of complications. The 47 cases of cerebellopontine angle tumors include 34 cases of epidermoid cysts, 7 cases of vestibular schwannomas, and 6 cases of meningiomas. All patients underwent fully neuroendoscopic surgery. Twenty tumors were removed using the one-surgeon two-hands technique, and 27 tumors were removed using the two-surgeons four-hands technique. The anatomical integrity of the affected cranial nerves was preserved in all 47 cases. None of the patients suffered a postoperative hemorrhage, cerebrospinal fluid leak, and aseptic or septic meningitis, or died. The rate of total tumor resection was 72.3% (34/47), and the symptom improvement rate was 89.4% (42/47). All patients were followed up for 2 to 12 months, and none died nor showed any signs of tumor recurrence. By analyzing 47 fully neuroendoscopic resections of CPA tumors using the posterior sigmoid sinus approach in our center, we believe that such method allows complete, safe, and effective resection of CPA tumors and is thereby worthy of clinical promotion.

Endoscopic Endonasal Approach for Trigeminal Schwannomas: Tailored Approaches Based on Lesion Traits

OBJECTIVES

To describe four endoscopic endonasal subapproaches, namely, the trans-lamina papyracea, trans-prelacrimal recess, trans-Meckel's cave, and transclival approaches for trigeminal schwannomas (TSs).

METHODS

This retrospective study reviewed the medical records and intraoperative videos of 38 patients with TSs who underwent endoscopic endonasal approach (EEA) between Jan 2013 and Dec 2021.

RESULTS

According to Jeong's classification, for TS equally in middle and posterior fossae (MP), a purely trans-Meckel's cave approach was carried out in 2 cases, and a combined transclival approach was carried out in 4 cases. The four tumors that involved infratemporal fossa (two E3, one mE3, and one Mpe3) were performed via a trans-prelacrimal recess approach, and type Mpe3 was also assisted by the trans-Meckel's cave approach. One patient with type E1 was treated with a trans-lamina papyracea approach. The other 27 cases, including type M, Mp, ME2, and MpE2, were all removed by a purely trans-Meckel's cave approach. Thirty-six patients (97.4%) received total resection under a purely EEA. The functional abilities and preoperative symptoms of 31 patients (88.6%) improved. Eight (21.1%) patients experienced permanent neurological function deficits. Postoperative cerebrospinal fluid and intraoperative internal carotid artery injury occurred in 1 (2.6%) patient.

CONCLUSION

According to the specific endoscopic endonasal subapproaches corresponding to the different TS locations, satisfactory results can be obtained for most types of tumors. It represents an effective alternative to the open transcranial approach and can also be properly used in most types of TS with experienced hands.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:2564-2571, 2023.

Endoscopic far-lateral supracerebellar infratentorial approach for resection of dumbbell-shaped trigeminal schwannoma: surgical techniques and preliminary results

BACKGROUND

Trigeminal schwannomas (TSs) are mostly benign tumors. However, dumbbell-shaped TSs are most challenging for surgeons and pose a high surgical risk.

OBJECTIVE

We describe the technique of the purely endoscopic far-lateral supracerebellar infratentorial approach (EFL-SCITA) for removing dumbbell-shaped TSs and further discuss the feasibility of this approach and our experience.

METHODS

EFL-SCITA was performed for resection of 5 TSs between January 2020 and March 2023. The entire procedure was performed endoscopically with the goal of total tumor resection. During the operation, the tumor was exposed in close proximity and multiple angles under the endoscope, and the peri-tumor nerves were carefully identified and protected, especially the normal trigeminal fiber bundles around the tumor.

RESULTS

All the tumors of 5 patients involved the middle and posterior cranial fossa, of which total removal was achieved in 2 patients and near-total removal in 3 patients. The most common preoperative symptoms were relieved after surgery. Two patients had postoperative mild facial paralysis (House-Brackmann grade II), and 1 patient had abducens palsy; both recovered during the follow-up period. Two patients experienced new postoperative facial hypesthesia, and 1 experienced mastication weakness, which did not recover. There was no tumor recurrence or residual tumor growth during the follow-up period in any of the patients.

CONCLUSION

EFL-SCITA is a new and effective alternative for the surgical treatment of TSs. For dumbbell-shaped TSs, this approach provides sufficient surgical field exposure and freedom of operation.

Comparison of the Retrosigmoid Suprameatal and Anterior Subtemporal Transpetrosal Approaches After Full Exposure of the Internal Acoustic Meatus

BACKGROUND AND OBJECTIVES

Surgical approaches to the ventral brainstem and petroclival regions are complex, and standard retrosigmoid and subtemporal approaches are often inadequate. Retrosigmoid suprameatal tubercle (RSMTA) and anterior subtemporal transpetrosal (ASTA) approaches may provide extended surgical exposure with less brain retraction. The objective of this study was to evaluate advantages and disadvantages of RSMTA vs ASTA, and illustrate the surgical corridors and 3-dimensional microsurgical anatomy of the related structures.

METHODS

Four silicone-injected adult cadaver heads (8 sides) were dissected to evaluate the accessibility of lesions located at the petrous apex, ventral brainstem, and pontomedullary region using ASTA and RSTMA.

RESULTS

Both ASTA and RSMTA provide access from the petrous apex to the ventral lower pons and pontomedullary junction. A greater extent of safely resected bone was found in ASTA vs RSMTA. ASTA provides a larger surgical view to the ventrolateral midpons, peritrigeminal region, superior neurovascular complex, pontomesencephalic junction, and posterior cavernous sinus. Meanwhile, through cranial nerve V mobilization, RSMTA provides a larger surgical view to the lower half part of the pons, ventrolateral part of the pontomedullary junction, and middle and lower neurovascular structures.

CONCLUSION

The choice of surgical approach is determined by considering the area where the lesion originates, lesion size, the anatomic structures to which it extends, and evaluation of the area that can be surgically exposed. Our study highlights the differences between these approaches and important surgical anatomic considerations.

Outcomes following surgical resection of trigeminal schwannomas: a systematic review and meta-analysis

Although typically benign, trigeminal schwannomas (TS) may require surgical resection when large or symptomatic and can cause significant morbidity. This study aims to summarize the literature and synthesize outcomes following surgical resection of TS. A systematic review was performed according to PRISMA guidelines. Data extracted included patient and tumor characteristics, surgical approaches, and postoperative outcomes. Odds ratios (OR) with corresponding 95% confidence intervals (CI) were used for outcome analysis. The initial search yielded 1838 results, of which 26 studies with 974 patients undergoing surgical resection of TS were included. The mean age was 42.9 years and 58.0% were female. The mean tumor diameter was 4.7 cm, with Samii type A, B, C, and D tumors corresponding to 33.4%, 15.8%, 37.2%, and 13.6%, respectively. Over a mean symptom duration of 29 months, patients presented with trigeminal hypesthesia (58.7%), headache (32.8%), trigeminal motor weakness (22.8%), facial pain (21.3%), ataxia (19.4%), diplopia (18.7%), and visual impairment (12.0%). Surgical approaches included supratentorial (61.4%), infratentorial (15.0%), endoscopic (8.6%), combined/staged (5.3%), and anterior (5.7%) or posterior (4.0%) petrosectomy. Postoperative improvement of facial pain (83.9%) was significantly greater than trigeminal motor weakness (33.0%) or hypesthesia (29.4%). The extent of resection (EOR) was reported as gross total (GTR), near total, and subtotal in 77.7%, 7.7%, and 14.6% of cases, respectively. Over a mean follow-up time of 62.6 months, recurrence/progression was noted in 7.4% of patients at a mean time to recurrence of 44.9 months. Patients with GTR had statistically significantly lower odds of recurrence/progression (OR: 0.07; 95% CI: 0.04-0.15) compared to patients with non-GTR. This systematic review and meta-analysis report patient outcomes following surgical resection of TS. EOR was found to be an important predictor of the risk of recurrence. Facial pain was more likely to improve postoperatively than facial hypesthesia. This work reports baseline rates of post-operative complications across studies, establishing benchmarks for neurosurgeons innovating and working to improve surgical outcomes for TS patients.

Middle cranial fossa trigeminal schwannoma resection through endoscopic transnasal maxillary sinus approach: A case report and literature review

The endoscopic transnasal maxillary sinus approach is usually performed in resecting tumors located in the pterygopalatine fossa and infratemporal fossa, but is rarely used in the resection of lesions in the middle cranial fossa. Because of the complicated anatomical structure of the middle cranial fossa, trigeminal schwannomas (TSs) located in this region are usually dissected through conventional craniotomy surgical approaches; however, the endoscopic transnasal maxillary sinus approach can be used in resection of middle cranial fossa TSs. The current study presented the case of a 59-year-old man who suffered intermittent headaches for 2 years without other notable medical history and neurological abnormalities. The patient was diagnosed with a middle cranial fossa TS. After imaging and assessment of anatomical features, the tumor was totally resected through the transnasal maxillary sinus approach. Following surgery, the symptoms were relieved and the patient returned to a normal life. Light numbness was complained of in the distribution area of the maxillary nerve of the right side of the face, but this was gradually relieved. Combined with a literature review, the present case indicated that the endoscopic transnasal maxillary sinus approach may provide a safer and more direct option for resecting middle cranial fossa lesions, which is worthy of increased clinical application.

The mini-combined transpetrosal approach: an anatomical study and comparison with the combined transpetrosal approach

BACKGROUND

The combined transpetrosal approach (CTPA) is a versatile technique suitable for challenging skull base pathologies. Despite the advantages provided by a wide surgical exposure, the soft tissue trauma, complex and time-consuming bony work, and cosmetic issues make it far from patient expectations. In this study, the authors describe a less invasive modification of the CTPA, the mini-combined transpetrosal approach (mini-CTPA), and perform a quantitative comparison between these two approaches.

METHODS

Five human specimens were used for this study. CTPA was performed on one side and mini-CTPA on the opposite side. The surgical freedom, petroclival and brainstem area of exposure, and maneuverability for 6 anatomical targets, provided by the CTPA and mini-CTPA, were calculated and statistically compared. The bony volumes corresponding to each anterior petrosectomy were also measured and compared. Three clinical cases with an operative video are also reported to illustrate the effectiveness of the approach.

RESULTS

The question-mark skin incision done along the muscle attachments permits an optimal cosmetic result. Even though the limited incision, the smaller craniotomy, and the less extensive bone drilling of mini-CTPA provide a smaller area of surgical freedom, the areas of exposure of petroclival region and brainstem were not statistically different between the two approaches. The antero-posterior maneuverability for the oculomotor foramen (OF), Meckel's cave (MC) and the REZ of trigeminal nerve, and the supero-inferior maneuverability for OF, MC, Dorello's canal, and REZ of CN VII are significantly reduced by the smaller opening. The bony volume of anterior petrosectomy resulted similar among the approaches.

CONCLUSIONS

The mini-CTPA is an interesting alternative to the CTPA, providing comparable surgical exposure both for petroclival region and for brainstem. Although the lesser soft tissue dissection and bony opening decrease the surgical maneuverability, the mini-CTPA may reduce surgical time, potential approach-related morbidities, and improve cosmetic and functional outcomes for the patients.

Management of non-vestibular schwannomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section Part II: Trigeminal and facial nerve schwannomas (CN V, VII)

BACKGROUND

Non-vestibular schwannomas are relatively rare, with trigeminal and jugular foramen schwannomas being the most common. This is a heterogenous group which requires detailed investigation and careful consideration to management strategy. The optimal management for these tumours remains unclear and there are several controversies. The aim of this paper is to provide insight into the main principles defining management and surgical strategy, in order to formulate a series of recommendations.

METHODS

A task force was created by the EANS skull base section committee along with its members and other renowned experts in the field to generate recommendations for the surgical management of these tumours on a European perspective. To achieve this, the task force performed an extensive systematic review in this field and had discussions within the group. This article is the second of a three-part series describing non-vestibular schwannomas (V, VII).

RESULTS

A summary of literature evidence was proposed after discussion within the EANS skull base section. The constituted task force dealt with the practice patterns that exist with respect to pre-operative radiological investigations, ophthalmological assessments, optimal surgical and radiotherapy strategies, and follow-up management.

CONCLUSION

This article represents the consensually derived opinion of the task force with respect to the treatment of trigeminal and facial schwannoma. The aim of treatment is maximal safe resection with preservation of function. Careful thought is required to select the appropriate surgical approach. Most middle fossa trigeminal schwannoma tumours can be safely accessed by a subtemporal extradural middle fossa approach. The treatment of facial nerve schwannoma remains controversial.

Clinical and Imaging Response to Trigeminal Schwannoma Radiosurgery: A Retrospective Analysis of a 28-Year Experience

Objective  The purpose of this study was to evaluate long-term clinical outcomes and tumor control after stereotactic radiosurgery (SRS) for trigeminal schwannoma (TS). Methods  During a 28-year period (1989-2017), 50 patients underwent SRS for TS. The median patient age was 51 years (range: 15-87 years). A total of 17 patients had a previous tumor resection: 10 had a single procedure, 5 had two procedures, and 2 had three procedures. The median and mean times between tumor resection and SRS were 12 and 24 months (range: 1-90 months), respectively. Four patients had neurofibromatosis II (NF2). Based on location, tumors were classified as root type (7), ganglion type (22), or dumbbell type (21). The median radiosurgery target volume was 3.4 cm ³ (range: 0.10-18 cm ³ ), median target dose was 14 Gy (range: 12-20 Gy), and the median number of isocenters was 6 (range: 1-15). The median and mean times to last follow-up was 36.9 and 55.2 months (range: 4-205 months), respectively. Eighteen patients (36%) had longer than 5-year follow-up, and seven patients (14%) had longer than 10-year follow-up. Results  The tumor control rate was 92% and the clinical improvement or stabilization rate was 94%. After SRS, the rates of progression free survival (PFS) at 1, 5, and 10 years were 98, 84, and 84%, respectively. Factors associated with improved PFS were female sex ( p  = 0.014) and smaller tumor volume ( p  = 0.022). In this series, we did not find that tumor type (root, ganglion, and dumbbell) had a statistically significant correlation to PFS. Forty-seven patients had neurological signs or symptoms at presentation. At last follow-up, neurological signs or symptoms improved in 22/47 (47%), remained unchanged in 24/50 (48%), and worsened due to tumor progression in 3/50 (6%). One patient (2%) developed temporary symptomatic adverse radiation effect (ARE) and three additional patients (6%) had transient imaging evidence of peritumoral reactive edema but no new symptoms. Conclusion  As a single outpatient procedure, SRS was associated with long-term freedom from additional management in 84% of patients. Nearly half the treated patients experienced improvement in neurological symptoms or signs.

Trigeminal schwannoma: a single-center experience with 43 cases and review of literature

OBJECTIVE

Trigeminal schwannomas (TS) are rare, when compared to vestibular schwannomas. The present study aims to analyze the clinical characteristics and surgical strategies of TS via the retrospective analysis of the clinical data of 43 patients.

METHODS

The clinical information of 43 patients diagnosed with TS, who were surgically treated from January 2008 to January 2018, was retrospectively analyzed. Then, the selection of approaches and surgical strategies were discussed.

RESULTS

During the last 10 years, 43 patients with TS received surgical treatment at Xuan Wu Hospital of Capital Medical University. Facial numbness and hypoesthesia were the most common symptoms, which developed in 29 cases (67.4%). Typical trigeminal neuralgia was complained by four patients (9.3%), while trigeminal motor impairment developed in nine cases (20.9%). The tumor was totally removed in 39 patients (90.7%), near-totally removed in three patients (7.0%), and partially removed in one patient (2.3%) due to intraoperative internal carotid artery (ICA) injury. The abducens was intraoperatively damaged in two patients (4.7%). After the operation, all four patients with trigeminal neuralgia achieved total recovery, but the facial numbness still continued in 24 patients (82.8%). At a median of 45.3 ± 25.5 (6-84) months of follow up, a tumor recurred in only one patient, and this patient received a second operation.

CONCLUSION

It can be concluded that total removal via the proper approach can be the best treatment for TS with a low complication rate. However, preoperative symptoms, such as facial numbness and trigeminal motor impairment that seldom improved though normal fibers, were carefully recognized and preserved during the operation.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Single-stage endoscopic endonasal approach for the complete removal of trigeminal schwannomas occupying both the middle and posterior fossae

To introduce a purely endoscopic endonasal trans-Meckel's cave approach or a transclival approach for trigeminal schwannomas (TSs) involving both the middle and posterior fossae. This retrospective study reviewed the medical records and intraoperative videos of 8 patients with TSs occupying both the middle and posterior fossae who underwent an endoscopic endonasal approach (EEA) between January 2017 and October 2019. All 8 patients received total resection under a single-stage EEA. Six patients underwent endoscopic endonasal resection via a purely trans-Meckel's cave approach, and 2 patients underwent endoscopic endonasal resection via a trans-Meckel's cave approach combined with a transclival approach. There was no surgical-related hemorrhage or mortality and no cerebrospinal fluid leakage. All headache symptoms completely improved postoperatively (n = 3 patients). All cranial nerve (CN) symptoms (CN IX and CN VI) improved postoperatively. The most common preoperative symptom was facial numbness (n = 5 patients); 2 of these 5 patients showed a partial improvement, 1 patient experienced worsening, and 2 patients remained unchanged at the last follow-up. Four patients developed postoperative complications, including CN VI palsy (n = 2), dry eye (n = 2), mastication weakness (n = 1), and facial numbness (n = 2). All complications except for dry eye were relieved at the last follow-up, but the patients with dry eye did not develop corneal keratopathy. The endoscopic endonasal trans-Meckel's cave and transclival approaches provide adequate exposure and improve the rate of total resection for TSs occupying both the middle and posterior fossae with minimal invasion. It may be possible to use these approaches as a safe alternative to conventional surgical approaches.

Microsurgical Management of Trigeminal Schwannoma: Cohort Analysis and Systematic Review

Background  Trigeminal schwannomas are benign tumors with a predilection for women between 40 and 60 years of age and account for less than 0.5% of all intracranial tumors. Clinical presentation depends on size and location, and typical symptoms are ipsilateral hypesthesia, headache, and facial pain. Clinical features and imaging usually make the Diagnosis. Methods  A retrospective cohort analysis of 14 patients treated at our institution between January 1999 and October 2016 was performed, with a critical and systematic review of data from the literature, focusing on articles published over the same period. Results  Fourteen patients were included in our series comprised of mostly women with a mean age of 40 years. Lesion size ranged from 3 to 6.5 cm (mean 4.6 cm). Clinical status of patients was evaluated and also rated based on the Karnofsky Perfomance Scale with values greater than 90% found in all patients pre and postoperatively. Surgery was our treatment of choice, and gross total resection was achieved in 71% of patients. Associated morbidity was high at 57%, predominantly from cranial nerve palsy, and no deaths were encountered. Conclusions  Microsurgery is a suitable treatment for large symptomatic trigeminal schwannomas, achieving good local control rates over the observation period at acceptable morbidity. Therefore, microsurgery appears to a suitable option. During the study period, a significant evolution in the availability of treatment methods occurred. Radiosurgery emerged as an alternative treatment for unresectable lesions. A comprehensive review of the available literature was performed, and results were compared according to treatment modality.

Endoscopic endonasal approach for trigeminal schwannomas: our experience of 39 patients in 10 years

BACKGROUND

The anatomical locations involved in trigeminal schwannomas (TSs) are quite complex. The endoscopic endonasal approach provides a minimal damage access corridor to both anterior and middle skull base for surgery. Given the nerve function recovery and postoperative neurological deterioration varied in different reports, the author demonstrates his surgery tips and the functional outcomes under endoscopic surgery in one single institution.

METHODS

A retrospective review of patients with TSs was undertaken to assess the outcome of endoscopic surgery from 2006 to 2016. Clinical features, imaging findings, preoperative/postoperative neurological deficits, surgical approaches and followed up data were collected.

RESULTS

Thirty-nine patients with TSs were included in this study. Surgical approaches include endoscopic medial maxillectomy approach (n = 8), endoscopic endonasal-assisted sublabial transmaxillary approach (n = 27) and endoscopic endonasal-assisted sublabial transmaxillary combined with septectomy (n = 4). Gross total resection and sub-total resection were achieved in 27 and 10 patients, respectively. The most common chief complaint was facial numbness, accounting for 41%, with a resolved rate of 62.5% after treatment. Fifteen patients developed new neurologic symptoms, including facial numbness/pain (n = 9 and 2, respectively), dry eye (n = 3) and mastication weakness (n = 1). Eight of these patients had partial improvement except for patients with dry eye.

CONCLUSION

Endoscopic endonasal approach represents a safe and effective surgical procedure for TSs in pterygopalatine fossa, infratemporal fossa and even Meckel cave. Tumor resection can be achieved by endoscope with few neurologic deficits and complications.

Single Stage Complete Removal of Dumbbell Trigeminal Schwannoma in a Child by Skull Base Approach

Trigeminal schwannomas (TSs) are extremely rare tumors in childhood, particularly in the absence of neurofibromatosis. Although multi-staged surgical strategies have been reported in the literature, safe and single stage microsurgical removal is possible. We report a rare case of dumbbell TS, in a 9-year-old girl in whom single stage complete removal was done using fronto-temporo-orbito-zygomatic craniotomy and sub temporal approach.

Retrosigmoid Intradural Suprameatal-Inframeatal Approach for Complete Surgical Removal of a Giant Recurrent Vestibular Schwannoma with Severe Petrous Bone Involvement: Technical Case Report

BACKGROUND

Surgical removal of giant vestibular schwannomas with severe petrous bone involvement remains challenging due to the high risk of complications. The retrosigmoid intradural suprameatal-inframeatal approach (RISIA) allows for safe exposure extending from Meckel's cave to the petrous internal carotid artery (ICA).

CASE DESCRIPTION

A 27-year-old man presented with recurrence of a giant vestibular schwannoma (4.5 cm) invading Meckel's cave and the left petrous ICA. Symptoms included complete left facial palsy and hearing loss due to tumor invasion and previous operations, as well as left-sided trigeminal hypesthesia, abducens nerve palsy, and lower cranial nerve dysfunction due to tumor compression. The patient also exhibited severe discoordination and ataxia. The tumor was completely resected via the RISIA, which involved drilling of the suprameatal and inframeatal portions of the petrous bone. No approach-related complications were observed. Full recovery of cranial nerve functions (with the exception of those related to the facial and cochlear nerves) and balance were observed postoperatively.

CONCLUSIONS

The RISIA allows for safe and effective surgical access during complete tumor resection, even when severe involvement of Meckel's cave and the petrous ICA are observed. The present report is the first to demonstrate the usefulness of this approach in patients with recurrent giant vestibular schwannoma.

Surgical Resection of Cerebellopontine Epidermoid Cysts: Limitations and Outcome

Objective  Epidermoid cysts are benign slowly growing tumors commonly involving the cerebellopontine angle (CPA). The aim of this study was to analyze the surgical limitations, surgical strategies, complications, and outcome of resection of these lesions. Material and Methods  The clinical data and outcome of 32 cases operated for CPA epidermoid between 2007 and 2015 were retrospectively analyzed. The mean follow-up period was 42.6 months, and all patients were followed up at least for a whole year. Results  There were 15 males and 17 females. The median age was 37.6 years. Headache and cranial nerves dysfunction were the most common presenting symptoms. Surgery was performed in all patients using the standard lateral suboccipital retrosigmoid approach. In three cases, microvascular decompression of an arterial loop was performed in addition to tumor excision. Total resection was accomplished in 19 out of 32 cases (59.4%), subtotal resection in 7 cases (21.9%), and only partial excision was achieved in 6 cases (18.7%). There was no recurrence or regrowth of residual tumor during the follow-up period. We had a single postoperative mortality due to postoperative pneumonia and septic shock. New cranial nerves deficits occurred in 15.6% of cases but were transient in most of them. Conclusion  The favorable outcome of total resection of CPA epidermoids should always be weighed against the critical risks that accompany it especially in the presence of tight adhesions to vital neurovascular structures. The retrosigmoid approach is suitable for the resection of these tumors even if they were large in size.

Multimodality Management of Trigeminal Schwannomas

Patients presenting with trigeminal schwannomas require multimodality management by a skull base surgical team that can offer expertise in both transcranial and transnasal approaches as well as radiosurgical and microsurgical strategies. Improvement in neurologic symptoms, preservation of cranial nerve function, and control of mass effect are the primary goals of management for trigeminal schwannomas. Complete surgical resection is the treatment of choice but may not be possible in all cases. Radiosurgery is an option as primary management for small- to moderate-sized tumors and can be used for postoperative residuals or recurrences. Planned surgical resection followed by SRS for residual tumor is an effective option for larger trigeminal schwannomas. The endoscopic resection is an excellent approach for patients with an extradural tumor or tumors isolated to the Meckel cave. A detailed analysis of a tumor and its surroundings based on high-quality imaging can help better estimate the expected outcome from each treatment. An expert skull base team should be able to provide precise counseling for each patient's situation for selecting the best option.

[Chondroma adjacent to Meckel's cave mimicking a fifth cranial nerve neurinoma. A case report]

Cranial chondromas are tumours arising from chondrocyte embryonic remnants cells that usually appear in the skull base synchondrosis. In contrast to the rest of the organism, where chondroid tumours are the most common primary bone tumour just behind the haematopoietic lineage ones, they are a rarity at cranial level, with an incidence of less than 1% of intracranial tumours. The case is reported on a 42 year-old male referred to our clinic due to the finding of an extra-axial lesion located close to the Meckel's cave region, with extension to the posterior fossa and brainstem compression after progressive paraparesis of 6 months onset. With the diagnosis of trigeminal schwannoma, a subtotal tumour resection was performed using a combined supra-infratentorial pre-sigmoidal approach. The postoperative histopathology report confirmed the diagnosis of cranial chondroma.