Tag: Trigeminal schwannoma

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Microsurgical Resection Versus Stereotactic Radiosurgery for Trigeminal Schwannoma: A Meta-Analysis of 949 Patient Treatment Outcomes

Neurosurgery 97:545–558, 2025

Meta-analysis of 949 trigeminal schwannoma patients found stereotactic radiosurgery (SRS) led to greater improvement in facial hypesthesia and motor deficits, but surgery was superior for facial pain relief. Both approaches provided similar tumor control. Treatment should be individualized based on patient characteristics, tumor profile, and symptoms.

• Trigeminal schwannomas (TS) are rare, benign nerve sheath tumors, with no clear consensus on optimal treatment between surgical resection and stereotactic radiosurgery (SRS).

• Meta-analysis included 29 retrospective studies with 949 patients: 589 had SRS, 360 had surgery; larger tumors were more likely to be treated surgically.

• SRS led to significantly higher rates of facial hypesthesia (numbness) improvement (44% vs 12%) and lower rates of new hypesthesia (4% vs 15%) compared to surgery.

• Surgery was more effective for improving facial pain (81% vs 58% after SRS).

• Both SRS and surgery provided high and similar tumor control rates (89% SRS vs 91% surgery).

• Trigeminal motor function improved more after SRS, but data were limited.

• Treatment choice should be individualized, considering tumor size, patient characteristics, and presenting symptoms.

• Limitations include retrospective design, heterogeneous data, and lack of standardization for outcome measures.

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Preservation of cranial nerve function in large and giant trigeminal schwannoma resection

Acta Neurochirurgica (2024) 166:198

Trigeminal schwannomas (TSs) are intracranial tumors that can cause significant brainstem compression. TS resection can be challenging because of the risk of new neurologic and cranial nerve deficits, especially with large (≥ 3 cm) or giant (≥ 4 cm) TSs. As prior surgical series include TSs of all sizes, we herein present our clinical experience treating large and giant TSs via microsurgical resection.

Methods This was a retrospective, single-surgeon case series of adult patients with large or giant TSs treated with microsurgery in 2012–2023.

Results Seven patients underwent microsurgical resection for TSs (1 large, 6 giant; 4 males; mean age 39 ± 14 years). Tumors were classified as type M (middle fossa in the interdural space; 1 case, 14%), type ME (middle fossa with extracranial extension; 3 cases, 43%), type MP (middle and posterior fossae; 2 cases, 29%), or type MPE (middle/posterior fossae and extracranial space; 1 case, 14%). Six patients were treated with a frontotemporal approach (combined with transmastoid craniotomy in the same sitting in one patient and a delayed transmaxillary approach in another), and one patient was treated using an orbitofrontotemporal approach. Gross total resection was achieved in 5 cases (2 near-total resections). Five patients had preoperative facial numbness, and 6 had immediate postoperative facial numbness, including two with worsened or new symptoms. Two patients (28%) demonstrated new non-trigeminal cranial nerve deficits over mean follow-up of 22 months. Overall, 80% of patients with preoperative facial numbness and 83% with facial numbness at any point experienced improvement or resolution during their postoperative course. All patients with preoperative or new postoperative non-trigeminal tumor-related cranial nerve deficits (4/4) experienced improvement or resolution on follow-up. One patient experienced tumor recurrence that has been managed conservatively.

Conclusions Microsurgical resection of large or giant TSs can be performed with low morbidity and excellent long-term cranial nerve function.

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

Neurosurgery 94:165–173, 2024

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.

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Endoscopic far‑lateral supracerebellar infratentorial approach for resection of dumbbell‑shaped trigeminal schwannoma

Acta Neurochirurgica (2023) 165:2913–2921

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 (EFLSCITA) 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.

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Simplified anterior transpetrosal approach without superior petrosal sinus and tentorial incision for lesions centered in Meckel’s cave

Acta Neurochirurgica (2023) 165:1833–1839

The anterior transpetrosal approach (ATPA) is an effective method to reach lesions in the petroclival region. This approach involves many steps, including superior petrosal sinus (SPS) ligation and tentorial cutting. It is sometimes unnecessary to perform all procedures in the ATPA for certain lesions, especially those centered in the Meckel’s cave. Here, we present a simplified anterior transpetrosal approach (SATPA) without superior petrosal sinus and tentorial incision for lesions centered in the Meckel’s cave as a modified ATPA.

Methods This study included 13 patients treated with SATPA. The initial steps of SATPA are similar to ATPA, excluding a middle cranial fossa dural incision, SPS dissection, or tentorial incision. Histological examination was performed to understand the membrane structure of the trigeminal nerve, which runs through the Meckel’s cave.

Results Pathology revealed trigeminal schwannoma (n=11), extraventricular central neurocytoma (n=1), and a metastatic tumor (n=1). The average tumor size was 2.4 cm. The total removal rate was 76.9% (10/13). Permanent complications included trigeminal neuropathy in four cases and cerebrospinal fluid leakage in one case. Histological examination revealed the trigeminal nerve traverses the subarachnoid space from the posterior fossa subdural space to the Meckel’s cave and is covered with the epineurium in the inner reticular layer.

Conclusions We used SATPA for lesions located in the Meckel’s cave identified using histological examination. This approach may be considered for small- to medium-sized lesions centered in the Meckel space.

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Indications and outcomes of endoscopic transorbital surgery for trigeminal schwannoma based on tumor classification: a multicenter study with 50 cases

J Neurosurg 138:1653–1661, 2023

Trigeminal schwannoma is a rare CNS tumor and involves the multicompartmental skull base. Recently, the endoscopic transorbital approach (ETOA) has emerged as a technique for minimally invasive surgery. The objective of this study was to evaluate the optimal indications and clinical outcomes of the ETOA for trigeminal schwannomas based on their tumor classification.

METHODS Between September 2016 and February 2022, the ETOA was performed in 50 patients with trigeminal schwannoma at four tertiary hospitals. There were 15 men and 35 women in the study, with a mean age of 46.9 years. All tumors were classified as type A (predominantly involving the middle cranial fossa), type B (predominantly involving the posterior cranial fossa), type C (dumbbell-shaped tumors involving the middle and posterior fossa), or type D (involvement of the extracranial compartment). Type D tumors were also subclassified by ophthalmic division (D1), maxillary division (D2), and mandibular division (D3). Clinical outcome was analyzed, including extent of resection and surgical morbidities.

RESULTS In this study, overall gross-total resection (GTR) was performed in 35 (70.0%) of 50 patients and near-total resection (NTR) in 9 patients (18.0%). The mean follow-up period was 21.9 (range 1–61.7) months. There was no tumor regrowth or recurrence during the follow-up period. Based on the classification, there were 17 type A tumors, 20 type C, and 13 type D. There were no type B tumors. Of the 13 type D tumors, 7 were D1, 1 D2, and 5 D3. For type A tumors, GTR or NTR was achieved using an ETOA in 16 (94.1%) of 17 patients. Eighteen (90.0%) of 20 patients with type C tumors attained GTR or NTR. Ten (76.9%) of 13 patients with type D tumors underwent GTR. Statistical analysis showed that there was no significant difference in the extent of resection among the tumor subtypes. Surgical complications included transient partial ptosis (n = 4), permanent ptosis (n = 1), transient diplopia (n = 7), permanent diplopia (n = 1), corneal keratopathy (n = 7), difficulties in mastication (n = 5), and neuralgic pain or paresthesia (n = 14). There were no postoperative CSF leaks or enophthalmos during follow-up.

CONCLUSIONS This study showed that trigeminal schwannomas can be effectively treated with a minimally invasive ETOA in all tumor types, except those predominantly involving the posterior fossa (type B). For the extracranial compartments, D2 or D3 tumor types often require an ETOA combined with the endoscopic endonasal approach, while D1 tumor types can be treated using an ETOA alone.

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Combined endoscopic endonasal transpterygoid and sublabial transmaxillary approaches for a large infratemporal fossa trigeminal schwannoma

Acta Neurochirurgica (2022) 164:2525–2531

Trigeminal schwannomas (TSs) with solitary extracranial location are rare, and surgical excision is challenging. In recent years, the endoscopic endonasal transmaxillary transpterygoid approach (EETPA) has been advocated as an effective strategy for TSs in the infratemporal fossa (ITF).

Method We describe the steps of the EETPA combined with the sublabial transmaxillary approach for the surgical excision of a giant mandibular schwannoma of the ITF. Indications, advantages, and approach-specific complications are also discussed. The main surgical steps are shown in an operative video.

Conclusion A combined EETPA and sublabial transmaxillary approach represents a safe and effective option for the surgical excision of extracranial TSs.

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Endoscopic transorbital and endonasal approach for trigeminal schwannomas

J Neurosurg 133:467–476, 2020

Trigeminal schwannomas are rare neoplasms with an incidence of less than 1% that require a comprehensive surgical strategy. These tumors can occur anywhere along the path of the trigeminal nerve, capable of extending intradurally into the middle and posterior fossae, and extracranially into the orbital, pterygopalatine, and infratemporal fossa. Recent advancements in endoscopic surgery have suggested a more minimally invasive and direct route for tumors in and around Meckel’s cave, including the endoscopic endonasal approach (EEA) and endoscopic transorbital superior eyelid approach (ETOA). The authors assess the feasibility and outcomes of EEA and ETOA for trigeminal schwannomas.

METHODS A retrospective multicenter analysis was performed on 25 patients who underwent endoscopic surgical treatment for trigeminal schwannomas between September 2011 and February 2019. Thirteen patients (52%) underwent EEA and 12 (48%) had ETOA, one of whom underwent a combined approach with retrosigmoid craniotomy. The extent of resection, clinical outcome, and surgical morbidity were analyzed to evaluate the feasibility and selection of surgical approach between EEA and ETOA based on predominant location of trigeminal schwannomas.

RESULTS According to predominant tumor location, 9 patients (36%) had middle fossa tumors (Samii type A), 8 patients (32%) had dumbbell-shaped tumors located in the middle and posterior cranial fossae (Samii type C), and another 8 patients (32%) had extracranial tumors (Samii type D). Gross-total resection (GTR, n = 12) and near-total resection (NTR, n = 7) were achieved in 19 patients (76%). The GTR/NTR rates were 81.8% for ETOA and 69.2% for EEA. The GTR/NTR rates of ETOA and EEA according to the classifications were 100% and 50% for tumors confined to the middle cranial fossa, 75% and 33% for dumbbell-shaped tumors located in the middle and posterior cranial fossae, and 50% and 100% for extracranial tumors. There were no postoperative CSF leaks. The most common preoperative symptom was trigeminal sensory dysfunction, which improved in 15 of 21 patients (71.4%). Three patients experienced new postoperative complications such as vasospasm (n = 1), wound infection (n = 1), and medial gaze palsy (n = 1).

CONCLUSIONS ETOA provides adequate access and resectability for trigeminal schwannomas limited in the middle fossa or dumbbell-shaped tumors located in the middle and posterior fossae, as does EEA for extracranial tumors. Tumors predominantly involving the posterior fossa still remain a challenge in endoscopic surgery.

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Identification of cranial nerves around trigeminal schwannomas using diffusion tensor tractography

Identification of cranial nerves around trigeminal schwannomas using diffusion tensor tractography

Acta Neurochir (2016) 158:429–435

There are no large series studies identifying the locations of cranial nerves (CNs) around trigeminal schwannomas (TSs); however, surgically induced cranial neuropathies are commonly observed after surgeries to remove TSs. In this study, we preoperatively identified the location of CNs near TSs using diffusion tensor tractography (DTT).

Methods An observational study of the DTT results and intraoperative findings was performed. We preoperatively completed tractography from images of patients with TSs who received surgical therapy. The result was later validated during tumorectomy.

Results A total of three consecutive patients were involved in this study. The locations of CNs V-VIII in relation to the tumor was clearly revealed in all cases, except for CN VI in case 3.The predicted fiber tracts were in agreement with intraoperative observations.

Conclusions In this study, preoperative DTT accurately predicted the location of the majority of the nerves of interest. This technique can be applied by surgeons to preoperatively visualize nerve arrangements.

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Endoscope-Assisted Retrosigmoid Intradural Suprameatal Approach for Surgical Treatment of Trigeminal Schwannomas

Endoscope-Assisted Retrosigmoid Intradural Suprameatal Approach

Operative Neurosurgery 10:565–575, 2014

Trigeminal schwannomas are the most common intracranial nonvestibular schwannomas, and the dumbbell-shaped subtype is the most challenging.

OBJECTIVE: To evaluate the efficiency and safety of the endoscope-assisted retrosigmoid intradural suprameatal approach (EA-RISA) for dumbbell trigeminal schwannomas and to compare EA-RISA with classic RISA.

METHODS: A retrospective study of all patients with trigeminal schwannomas was performed with a focus on dumbbell tumors. Tumors were classified according to a modified Samii classification. Extent of tumor removal, outcome, and morbidity rates in the 2 subgroups were compared.

RESULTS: Twenty patients were enrolled: 8 had dumbbell-shaped tumors (type C1), 8 had middle fossa tumors (A1-3), 3 had extracranial extension (D2), and 1 had posterior fossa tumor. Gross total resection was achieved in 15 and near-total resection in 5 patients. In 4 patients with dumbbell tumors, the classic RISA (Samii approach) was used; EA-RISA was used in the other 4 patients. The extent of petrous apex drilling was determined individually on the basis of the anatomic variability of suprameatal tubercle and degree of tumor-induced petrous apex erosion; in 2 patients, only minimal drilling was needed. The endoscope was applied after microsurgical tumor removal and in 3 of 4 patients revealed a significant unrecognized tumor remnant in the anterolateral and superolateral aspects of the Meckel cave. Thus, the EA-RISA technique allowed gross total resection of the tumor.

CONCLUSION: The EA-RISA enlarges the exposure obtained with the classic RISA. Its judicious use can help achieve safe and radical removal of dumbbell-shaped trigeminal schwannomas (C1 type).

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Operative management of trigeminal neuromas

trigeminal neuroma

Acta Neurochir (2014) 156:1105–1114

The trigeminal schwannoma is the second most common intracranial schwannoma. Their proximity to the critical skull base neural and vascular structures increases the complexity of surgical treatment. The aim of this study was to better understand the surgical approaches and the prognosis, as well as to assess the optimum therapeutic schedule.

Methods This was a retrospective study of 55 patients with trigeminal schwannomas who visited our department between Jan 2007 and Jan 2012. We analyzed the clinical and radiological presentation, tumor characteristics, surgical approaches, the prognosis.

Results The patients were 30 women and 25 men of mean age 36 years (range, 6–66 years) who received postoperative neurological and neuroradiological follow-up. The tumor was located in the middle fossa (type A) in 13 cases, in the posterior fossa (type B) in ten cases, in the middle and posterior fossae (type C) in 21 cases, and in the branches of the trigeminal nerve (type D) in 11 cases. The most common symptom was facial hypesthesia or numbness in 36 patients (65%) . Total and nearly total tumor resection was achieved in 51 cases (93 %). Three patients (5 %) had worsening of preexisting deficits and there was no perioperative mortality. With an average follow-up period of 35 months, facial hypesthesia persisted in 26 patients (72 %),and improved in ten patients (28 %). Facial pain was relieved in 11 patients (100 %). There has been a recurrence in one case (2%) and all patients resumed independent and social reintegration.

Conclusion This study demonstrates radical surgery with excellent neurological outcomes is the primary treatment of trigeminal schwannomas. Appropriate selection of surgical approach according to tumor types is highly important and necessary. The preoperative facial pain could be relieved, hypesthesia frequently remains or could even be worsened after surgery.

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Trigeminal Schwannomas: Skull Base Approaches and Operative Results in 105 Patients

Neurosurgery 70[ONS Suppl 1]:ons132–ons144, 2012 DOI: 10.1227/NEU.0b013e31822efb21

Trigeminal schwannomas make up 0.8% to 8% of all intracranial schwannomas.

OBJECTIVE: To analyze our surgical experience with trigeminal schwannomas.

METHODS: We performed 107 operations on 105 patients harboring trigeminal schwannomas over the past 30 years. We classified the tumors as peripheral, ganglion cavernous, posterior fossa root, and dumbbell types according to the portion of the nerve that gave rise to the tumor.

RESULTS: Fourteen were peripheral-type tumors (13.1%), 39 (36.4%) were ganglion cavernous type, 22 (20.6%) were posterior fossa root type, and 32 (30.0%) were dumbbell type. Sixty-five tumors were solid, 35 were mixed, and only 7 were cystic. Among solid tumors, 14 were vascular, fibrous, and adherent to adjacent structures. Total or near-total removal was performed in 86 cases (81.9%), and subtotal removal was achieved in 18 (17.1%). The most common symptom was facial hypesthesia, occurring in 69 patients. This symptom improved in 11 patients, persisted in 50 patients, and worsened in 8 patients after surgery. New postoperative hypesthesia was observed in 8 patients. The second most common symptom was facial pain, observed in 24 patients. Facial pain subsided in 22 and persisted in 2 patients after surgery. Diplopia was observed in 21 patients. This symptom improved postoperatively in 14 patients, persisted in 6 patients, and worsened in 1 patient.

CONCLUSION: The present series demonstrates acceptable results using microsurgical treatment to remove trigeminal schwannomas. Pain and diplopia may be relieved after surgery; however, hypesthesia frequently remains or may be worsened by surgery.

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