Surgical outcomes of lateral approach for jugular foramen schwannoma: postoperative facial nerve and lower cranial nerve functions

Surgical management of large lower cranial nerves schwannomas: long term results of a less aggressive resection strategy

In an effort to reduce the high morbidity and life-threatening complications after radical resection in large schwannoma surgery, alternative strategies of nontotal resections have emerged. To evaluate the long term clinical and oncological outcome after lower cranial nerves (LCN) schwannoma surgery operated on with a cranial nerve-sparing technique. Single center retrospective cohort study of 8 consecutive patients harboring LCN schwannomas operated on between March 2005 and October 2021. The mean LCN schwannoma diameter was 33 mm (range 26-51). Seven patients (87,5%) underwent a modified retrosigmoid approach. Three patients underwent gross total resection (37,5%), 3 had received neartotal resection (mean tumor residue 0,25 cc) and subtotal resection in 2 patients who presented with an extracranial extension of the tumor (mean tumor residue 2,44 cc). Both patients had received upfront additional GKRS. The three patients who presented with preoperative CN IX & X injuries recovered within 6 months after surgery. All of the five patients freed from any preoperative CNs IX & X symptoms experienced transient (80%) or definitive (one patient) disturbances after surgery. They all improved within 6 months but one who required long term gastrostomy feeding tube. This patient harbored a schwannoma originating from the glossopharyngeal nerve, which could not be anatomically preserved during surgery. Tumor control was achieved in 100% of cases with a mean follow-up of 91 months. LCN schwannomas could be surgically removed through a less aggressive non-radical resection strategy with acceptable functional results and excellent tumor control.

Comparative Anatomic Analysis of Neuronavigated Transmastoid-Infralabyrinthine Approaches for Jugular Fossa Pathologies: Short Anterior Rerouting Versus Nonrerouting and Tailored Nonrerouting Techniques

BACKGROUND AND OBJECTIVES

Access to the jugular fossa pathologies (JFPs) via the transmastoid infralabyrinthine approach (TI-A) using the nonrerouting technique (removing the bone anterior and posterior to the facial nerve while leaving the nerve protected within the fallopian canal) or with the short-rerouting technique (rerouting the mastoid segment of the facial nerve anteriorly) has been described in previous studies. The objective of this study is to compare the access to Fisch class C lesions (JFPs extending or destroying the infralabyrinthine and apical compartment of the temporal bone with or without involving the carotid canal) between the nonrerouting and the short-rerouting techniques. Also, some tailored steps to the nonrerouting technique (NR-T) were outlined to enhance access to the jugular fossa (JF) as an alternative to the short-rerouting technique.

METHODS

Neuronavigated TI-A was performed using the nonrerouting, tailored nonrerouting, and short-rerouting techniques on both sides of 10 human head specimens. Exposed area, horizontal distance, surgical freedom, and horizontal angle were calculated using vector coordinates for nonrerouting and short-rerouting techniques.

RESULTS

The short-rerouting technique had significantly higher values than the NR-T ( P < .01) for the exposed area (169.1 ± SD 11.5 mm 2 vs 151.0 ± SD 12.4 mm 2 ), horizontal distance (15.9 ± SD 0.6 mm vs 10.6 ± SD 0.5 mm 2 ), surgical freedom (19 650.2 ± SD 722.5 mm 2 vs 17 233.8 ± SD 631.7 mm 2 ), and horizontal angle (75.2 ± SD 5.1° vs 61.7 ± SD 4.6°). However, adding some tailored steps to the NR-T permitted comparable access to the JF.

CONCLUSION

Neuronavigated TI-A with the short-rerouting technique permits wider access to the JF compared with the NR-T. However, the tailored NR-T provides comparable access to the JF and may be a better option for class C1 and selected class C2 and C3 JFPs.

Lower Cranial Nerve Schwannomas: Cohort Study and Systematic Review

BACKGROUND AND OBJECTIVES

Schwannomas originating from the lower cranial nerves (LCNS) are rare and pose a significant surgical challenge. Resection is the mainstay treatment; however, risk of treatment morbidity is considerable, and the available literature regarding differential treatment outcomes in this vulnerable population is sparse.

METHODS

A single-institution cohort study and systematic literature review of LCNS were performed.

RESULTS

Fifty-eight patients were included: 34 underwent surgical resection and 24 underwent stereotactic radiosurgery (SRS). The median age at diagnosis was 48 years (range 17-74). Presenting symptoms were dysphagia (63%), dysarthria/hypophonia (47%), imbalance (33%), and hearing loss/tinnitus (30%). Tumor size was associated with surgical resection, as compared with initial SRS (4.1 cm vs 1.5 cm, P = .0001). Gross total resection was obtained in 52%, with tumor remnants predominantly localized to the jugular foramen (62%). Post-treatment worsening of symptoms occurred in 68% of surgical and 29% of SRS patients ( P = .003). Postoperative symptoms were mostly commonly hypophonia/hoarseness (63%) and dysphagia (59%). Seven patients (29%) had new neurological issues after SRS treatment, but symptoms were overall milder. The median follow-up was 60 months (range 12-252); 98% demonstrated meaningful clinical improvement. Eighteen surgical patients (53%) underwent adjuvant radiation at a median of 5 months after resection (range 2-32). At follow-up, tumor control was 97% in the surgical cohort and 96% among SRS patients.

CONCLUSION

Although LCNS resection is potentially morbid, most postoperative deficits are transient, and patients achieve excellent tumor control-particularly when paired with adjuvant SRS. For minimally symptomatic patients undergoing surgical intervention, we advise maximally safe resection with intracapsular dissection to preserve nerve integrity where possible. For residual or as a primary treatment modality, SRS is associated with low morbidity and high rates of long-term tumor control.

Early-onset adverse events after stereotactic radiosurgery for jugular foramen schwannoma: a mid-term follow-up single-center review of 46 cases

Background

Recently, stereotacitc radiosurgery (SRS) has been in the spotlight as an alternative therapeutic option for jugular foramen schwannomas (JFS). While most reported studies focus on the long-term efficacy and safety issues of SRS, none describe the early-onset adverse events (eAEs). We aimed to investigate the incidence, clinical characteristics, and mid-term outcomes of eAEs occurring within six months after SRS for JFS.

Methods

In this retrospective review, patients who underwent at least six months of follow-up were included among all patients with JFS who have performed SRS at our institution between July 2008 and November 2019. And eAEs were defined as a newly developed neurological deficit or aggravation of pre-existing symptoms during the first six months after SRS.

Results

Forty-six patients were included in the analysis. The median follow-up period was 50 months (range 9–136). The overall tumor control rate was 91.3%, and the actuarial 3-, 5-, and 10-year progression-free survival rates were 97.8%, 93.8%, and 76.9%, respectively. Of the 46 patients, 16 had eAEs, and the median time to onset of eAEs was one month (range 1–6 months), and the predominant symptoms were lower cranial nerve dysfunctions. Thirteen of 16 patients showed improved eAE symptoms during the follow-up period, and the median resolution time was six months (range 1–52). In 11 (68.8%) of 16 patients with eAEs, transient expansions were observed with a mean of 3.6 months after the onset of eAEs, and the mean difference between the initial tumor volume and the transient expansion volume was more prominent in the patients with eAEs (3.2 cm³ vs. 1.0 cm³; p = 0.057). In univariate analysis, dumbbell-shaped tumors (OR 10.56; p = 0.004) and initial tumor volume (OR 1.32; p = 0.033) were significantly associated with the occurrence of eAEs.

Conclusions

Although acute adverse events after SRS for JFS are not rare, these acute effects were not permanent and mostly improved with the steroid treatment. Dumbell-shaped and large-volume tumors are significant predictive factors for the occurrence of eAEs. And the transient expansion also seems to be closely related to eAEs. Therefore, clinicians need to be more cautious when treating these patients and closely monitor the occurrence of eAEs.

Intratumoral hemorrhage in jugular foramen schwannoma after stereotactic radiosurgery: A case report

Background:

Clinically significant intratumoral hemorrhage is a rare complication of stereotactic radiosurgery (SRS) for benign tumors.

Case Description:

Here, we present the case of a 64-year-old man who underwent SRS for a relatively large dumbbell-shaped left jugular foramen schwannoma (JFS) and thereafter developed intratumoral hemorrhage. On post-SRS day 3, he developed lower cranial nerve palsies with radiographically evident tumor expansion. His neurological conditions had gradually improved thereafter; however, he suddenly developed headache, dizziness, and mild hearing deterioration at 7 months due to intratumoral hemorrhage. We managed the patient conservatively, and eventually, his symptoms improved except for slight ataxia and hearing deterioration. Follow-up images at 4 years from SRS demonstrated significant tumor shrinkage. This is the first report describing intratumoral hemorrhage after SRS for JFS.

Conclusion:

Transient expansion of the tumor and subsequent venous stasis around the tumor may have played a role in the hemorrhage. Intratumoral hemorrhage should be considered as a rare, but potential complication of SRS for JFSs.

Aesthesiometer-Based Testing for Laryngopharyngeal Hyposensitivity

OBJECTIVES/HYPOTHESIS

To develop a method for threshold estimation of the laryngeal adductor reflex (LAR) response using Cheung-Bearelly monofilaments.

STUDY DESIGN

Cross-sectional.

METHODS

Twenty-two healthy adults (12 men, 10 women) were tested for LAR response outcome using 30 mm 5-0 and 4-0 nylon monofilaments. Tactile stimuli were delivered to the aryepiglottic (AE) fold and medial pyriform sinus (MPS). Dichotomous classifier features and performance (area under the curve (AUC)), the LAR response outcome agreement and disagreement matrix, and test-retest reliability were examined. From those data, a test protocol that would minimize patient burden to estimate the LAR triggering threshold was formulated.

RESULTS

Classifier performance of 5-0 monofilament stimulation of the AE fold (sensitivity = 0.63, specificity = 0.63, PPV = 0.74, NPV = 0.25) and MPS (sensitivity = 0.45, specificity = 0.77, PPV = 0.74, NPV = 0.23,) was slightly below that of 4-0 monofilament stimulation of the AE fold (sensitivity = 0.82, specificity = 0.50, PPV = 0.82, NPV = 0.50) and MPS (sensitivity = 0.84, specificity = 0.64, PPV = 0.90, NPV = 0.56), based on AUC. LAR response outcome agreement for 5-0 and 4-0 stimulations was high (93%) for 5-0 positive response, but low (29%) for 5-0 negative response. Aesthesiometer test-retest reliability for LAR response outcome was excellent (Cronbach's alpha = 0.97).

CONCLUSIONS

Threshold estimation of the LAR response may be operationalized by adopting a decision tree protocol. For negative LAR response to initial 5-0 monofilament stimulation and positive response to subsequent 4-0 monofilament stimulation, the higher threshold is confirmed. Positive LAR response to 5-0 or 4-0 monofilament stimulation is expected in over 90% of asymptomatic adults. Negative LAR response to 4-0 monofilament stimulation identifies patients at risk for laryngopharyngeal hyposensitivity.

LEVEL OF EVIDENCE

3b Laryngoscope, 2021.

Clinical Studies and Pre-clinical Animal Models on Facial Nerve Preservation, Reconstruction, and Regeneration Following Cerebellopontine Angle Tumor Surgery-A Systematic Review and Future Perspectives

Background and purpose: Tumorous lesions developing in the cerebellopontine angle (CPA) get into close contact with the 1st (cisternal) and 2nd (meatal) intra-arachnoidal portion of the facial nerve (FN). When surgical damage occurs, commonly known reconstruction strategies are often associated with poor functional recovery. This article aims to provide a systematic overview for translational research by establishing the current evidence on available clinical studies and experimental models reporting on intracranial FN injury.

Methods: A systematic literature search of several databases (PubMed, EMBASE, Medline) was performed prior to July 2020. Suitable articles were selected based on predefined eligibility criteria following the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines. Included clinical studies were reviewed and categorized according to the pathology and surgical resection strategy, and experimental studies according to the animal. For anatomical study purposes, perfusion-fixed adult New Zealand white rabbits were used for radiological high-resolution imaging and anatomical dissection of the CPA and periotic skull base.

Results: One hundred forty four out of 166 included publications were clinical studies reporting on FN outcomes after CPA-tumor surgery in 19,136 patients. During CPA-tumor surgery, the specific vulnerability of the intracranial FN to stretching and compression more likely leads to neurapraxia or axonotmesis than neurotmesis. Severe FN palsy was reported in 7 to 15 % after vestibular schwannoma surgery, and 6% following the resection of CPA-meningioma. Twenty-two papers reported on experimental studies, out of which only 6 specifically used intracranial FN injury in a rodent (n = 4) or non-rodent model (n = 2). Rats and rabbits offer a feasible model for manipulation of the FN in the CPA, the latter was further confirmed in our study covering the radiological and anatomical analysis of perfusion fixed periotic bones.

Conclusion: The particular anatomical and physiological features of the intracranial FN warrant a distinguishment of experimental models for intracranial FN injuries. New Zealand White rabbits might be a very cost-effective and valuable option to test new experimental approaches for intracranial FN regeneration. Flexible and bioactive biomaterials, commonly used in skull base surgery, endowed with trophic and topographical functions, should address the specific needs of intracranial FN injuries.

Long-Term Outcomes of Stereotactic Radiosurgery for Trigeminal, Facial, and Jugular Foramen Schwannoma in Comparison with Vestibular Schwannoma

Simple Summary

Intracranial schwannomas are benign intracranial neoplasms. Vestibular schwannomas (VS) account for 90% of intracranial schwannomas; whereas the other cranial nerve schwannomas, such as trigeminal (TS), facial (FS), and jugular foramen schwannoma (JFS), account for 10% of all cases. Stereotactic radiosurgery (SRS) is a minimally invasive treatment for small to medium VS and known to provide excellent long-term tumor control; however, there remains a paucity of evidence regarding SRS for TS, FS, and JFS due to the rarity of these tumors. We investigated the radiosurgical outcomes of these non-vestibular schwannomas and compared them to those of VS through matched cohort analysis.

Abstract

Stereotactic radiosurgery (SRS) is known to provide excellent tumor control with functional preservation for vestibular schwannomas (VS), but its efficacy in the other major intracranial schwannomas including trigeminal (TS), facial (FS), and jugular foramen schwannomas (JFS) has not been established yet due to their rarity. We retrospectively analyzed data of 514 consecutive patients who had intracranial schwannomas (460 VS, 22 TS, 7 FS, and 25 JFS) and underwent SRS. The 5- and 10-year tumor control rates were 97% and 94% for VS, 100% and 100% for TS, 80% and 80% for FS, and 100% and 80% for JFS. Radiation-induced complications included one hydrocephalus for TS (4.5%), no cases for FS (0%), and one hydrocephalus and one lower palsy for JFS (8.0%). Through matched cohort analysis between patients with VS and each of the non-VS, we found no statistical difference in tumor control and radiation-induced adverse events. SRS seems to provide long-term tumor control with functional preservation for TS, FS and JFS and the efficacies are similar to VS.

Strategy for facial nerve management during surgical removal of benign jugular foramen tumors: Outcomes and indications

OBJECTIVE

Classical surgical management of jugular foramen (JF) tumors usually requires facial nerve rerouting which results in permanent facial palsy in most patients. The purpose of the article is to study the outcomes of different rerouting techniques, and to discuss their indications.

MATERIAL AND METHODS

We retrospectively reviewed 98 patients with JF tumors operated at our center between January 2008 and December 2016 using different surgical approaches with the following procedures for facial nerve management: total anterior rerouting (TR), partial anterior rerouting (PR), and fallopian bridge (FB) technique. The data for facial nerve management, surgical outcome and postoperative facial nerve function were collected from the medical records.

RESULTS

In the study, there were 48 males and 50 females. Of them, 61 (62.2%) were jugular paragangliomas, 22 (22.4%) schwannomas, and 15 (15.3%) meningiomas. Total tumor removal was achieved in 95 (96.9%) patients, while near-total removal was achieved in 3 (3.1%) paragangliomas. TR was applied in 31 (31.6%) patients with PR in 26 (26.5%) patients, and FB in 41 (41.8%) patients. The mean follow-up duration was 39.4±22.6 months, and 2 recurrences of paragangliomas were observed. Seventy-five patients (76.5%) had good facial function (HB I-II) at 1 year after surgery, the patients who received a TR approach presented significantly less HB I-II FN function (48.4%) than those with PR (82.6%, P<0.05) or those with FB technique (95.1%, P<0.001). 21 patients (21.4%) presented new-onset lower cranial nerve dysfunction of which 13 recovered at 1 year after surgery.

CONCLUSION

Facial nerve management in JF tumors should be tailored individually. No-rerouting methods, such as the fallopian bridge technique, bring significantly better results in terms of facial nerve function, which might be performed first during surgery; its indication is based mainly on the tumor type and extent.

Stereotactic radiosurgery for jugular foramen schwannomas: an international multicenter study

OBJECTIVE

For some jugular foramen schwannomas (JFSs), complete resection is possible but may be associated with significant morbidity. Stereotactic radiosurgery (SRS) is a minimally invasive alternative or adjunct to microsurgery for JFSs. The authors reviewed clinical and imaging outcomes of SRS for patients with these tumors.

METHODS

Nine participating centers of the International Gamma Knife Research Foundation identified 92 patients who underwent SRS between 1990 and 2013. Forty-one patients had prior subtotal microsurgical resection. The median interval between previous surgery and SRS was 15 months (range 0.5–144 months). Eighty-four patients had preexisting cranial nerve (CN) symptoms and signs. The median tumor volume was 4.1 cm3 (range 0.8–22.6 cm3), and the median margin dose was 12.5 Gy (range 10–18 Gy). Patients with neurofibromatosis were excluded from this study.

RESULTS

The median follow-up was 51 months (range 6–266 months). Tumors regressed in 47 patients, remained stable in 33, and progressed in 12. The progression-free survival (PFS) was 93% at 3 years, 87% at 5 years, and 82% at 10 years. In the entire series, only a dumbbell shape (extension extracranially via the jugular foramen) was significantly associated with worse PFS. In the group of patients without prior microsurgery (n = 51), factors associated with better PFS included tumor volume < 6 cm3 (p = 0.037) and non–dumbbell-shaped tumors (p = 0.015). Preexisting cranial neuropathies improved in 27 patients, remained stable in 51, and worsened in 14. The CN function improved after SRS in 12% of patients at 1 year, 24% at 2 years, 27% at 3 years, and 32% at 5 years. Symptomatic adverse radiation effects occurred in 7 patients at a median of 7 months after SRS (range 5–38 months). Six patients underwent repeat SRS at a median of 64 months (range 44–134 months). Four patients underwent resection at a median of 14 months after SRS (range 8–30 months).

CONCLUSIONS

Stereotactic radiosurgery proved to be a safe and effective primary or adjuvant management approach for JFSs. Long-term tumor control rates and stability or improvement in CN function were confirmed.

Gamma Knife surgery for patients with jugular foramen schwannomas: a multiinstitutional retrospective study in Japan

OBJECTIVE This study aimed to explore the efficacy and safety of stereotactic radiosurgery in patients with jugular foramen schwannomas (JFSs). METHODS This study was a multiinstitutional retrospective analysis of 117 patients with JFSs who were treated with Gamma Knife surgery (GKS) at 18 medical centers of the Japan Leksell Gamma Knife Society. The median age of the patients was 53 years. Fifty-six patients underwent GKS as their initial treatment, while 61 patients had previously undergone resection. At the time of GKS, 46 patients (39%) had hoarseness, 45 (38%) had hearing disturbances, and 43 (36%) had swallowing disturbances. Eighty-five tumors (73%) were solid, and 32 (27%) had cystic components. The median tumor volume was 4.9 cm³, and the median prescription dose administered to the tumor margin was 12 Gy. Five patients were treated with fractionated GKS and maximum and marginal doses of 42 and 21 Gy, respectively, using a 3-fraction schedule. RESULTS The median follow-up period was 52 months. The last follow-up images showed partial remission in 62 patients (53%), stable tumors in 42 patients (36%), and tumor progression in 13 patients (11%). The actuarial 3- and 5-year progression-free survival (PFS) rates were 91% and 89%, respectively. The multivariate analysis showed that pre-GKS brainstem edema and dumbbell-shaped tumors significantly affected PFS. During the follow-up period, 20 patients (17%) developed some degree of symptomatic deterioration. This condition was transient in 12 (10%) of these patients and persistent in 8 patients (7%). The cause of the persistent deterioration was tumor progression in 4 patients (3%) and adverse radiation effects in 4 patients (3%), including 2 patients with hearing deterioration, 1 patient with swallowing disturbance, and 1 patient with hearing deterioration and hypoglossal nerve palsy. However, the preexisting hoarseness and swallowing disturbances improved in 66% and 63% of the patients, respectively. CONCLUSIONS GKS resulted in good tumor control in patients with either primary or residual JFSs. Although some patients experienced some degree of symptomatic deterioration after treatment, persistent adverse radiation effects were seen in only 3% of the entire series at the last follow-up. Lower cranial nerve deficits were extremely rare adverse radiation effects, and preexisting hoarseness and swallowing disturbances improved in two-thirds of patients. These results indicated that GKS was a safe and reasonable alternative to surgical resection in selected patients with JFSs.

A Single-Institution Retrospective Study of Jugular Foramen Schwannoma Management: Radical Resection Versus Subtotal Intracranial Resection Through a Retrosigmoid Suboccipital Approach Followed by Radiosurgery

BACKGROUND

Despite advances in skull base surgery, achieving effective surgical management of jugular foramen schwannomas (JFSs) that avoids postoperative cranial nerve (CN) deficits remains a challenge. Subtotal resection followed by radiosurgery (rather than radical resection) is increasingly being viewed as a better treatment strategy. Here, an institutional database was retrospectively analyzed for outcomes after surgical treatment of JFSs to evaluate the optimal strategy for managing JFSs.

METHODS

Twenty-two patients with JFSs were operated on by either radical resection (n = 13) or conservative resection plus radiosurgery (n = 9). These 2 different groups were compared in terms of early (≤4 weeks after surgery) and late postoperative functional outcome and oncologic control.

RESULTS

No deaths occurred in either group, but there were 3 surgery-related complications in the radical resection group. Postoperative CN deficits and additional procedures related to CN morbidity were generally higher in the radical resection group, but the differences were not statistically significant. The conservative surgery group showed a statistically significant improvement in the level of dysphagia and dysphagia-related functional state in the late postoperative period. There was 1 case of recurrence after radical resection over a mean follow-up period of 73 months. All tumors in the conservative surgery group were controlled over a mean period of 34 months.

CONCLUSIONS

Our results suggest that conservative resection of JFSs via a familiar intracranial approach plus radiosurgery may be an effective surgical alternative for improving functional outcome with adequate oncologic control.

Linear Accelerator Radiosurgery for Nonvestibular Schwannomas

BACKGROUND:

Nonvestibular schwannomas are uncommon tumors of the brain often treated by surgical resection. Surgery may be associated with high morbidity.

OBJECTIVE:

We present a series of nonvestibular schwannomas treated with linear accelerator radiosurgery during a 19-year period.

METHODS:

This is a retrospective analysis of patients who underwent treatment of nonvestibular schwannomas at the University of Florida with linear accelerator radiosurgery between August 1989 and February 2008. Forty-nine patients underwent treatment during the study period, and 6 were lost to follow up. The mean age was 51 years (range, 17-82 years), 39% had previous surgical resection, and 67% presented with preradiosurgery cranial nerve deficits. There were 25 trigeminal, 18 jugular foramen, 2 facial, 2 oculomotor, 1 hypoglossal, and 1 high cervical schwannomas. The median tumor volume was 5.3 mL (range, 0.3-24.5 mL), treated with a median dose of 1250 cGy (range, 1000-1500 cGy). Study endpoints were actuarial local tumor control and neurological outcome.

RESULTS:

Forty-three patients were available for a median follow-up of 37 months (range, 6-210 months). Actuarial local tumor control was 97% at 1 year, 91% at 4.5 years, and 83% at 5 years. There were 4 new cranial nerve deficits (9%) including facial numbness (2 patients), anesthesia dolorosa (1 patient), and facial weakness (1 patient). Thirty-nine percent had documented clinical and/or symptomatic improvement. There were no other morbidity and no mortality with treatment.

CONCLUSION:

Radiosurgery for nonvestibular schwannomas offers good actuarial local tumor control and has superior morbidity compared with surgical resection. This is the largest linear accelerator radiosurgical series, and the second largest radiosurgical series reported to date.