A hearing preservation technique for the resection of extensive jugular foramen tumors

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.

Microsurgical Anatomy of the Jugular Process as an Anatomical Landmark to Access the Jugular Foramen: A Cadaveric and Radiological Study

BACKGROUND

The jugular process forms the posteroinferior surface of the jugular foramen and is an important structure for surgical approaches to the foramen. However, its morphological features have not been well described in modern texts.

OBJECTIVE

To elucidate the microsurgical anatomy of the jugular process and examine its morphological features.

METHODS

Five adult cadaveric specimens were dissected in a cadaveric study, and computed tomography data from 31 heads (62 sides) were examined using OsiriX (Pixmeo SARL, Bernex, Switzerland) to elucidate the morphological features of the jugular process.

RESULTS

The cadaveric study showed that it has a close relationship with the sigmoid sinus, jugular bulb, rectus capitis lateralis, lateral atlanto-occipital ligament, and lateral and posterior condylar veins. The radiographic study showed that 9/62 sigmoid sinuses protruded inferiorly into the jugular process and that in 5/62 sides, this process was pneumatized. At the entry of the jugular foramen, if the temporal bone has a bulb-type jugular bulb, and if surgery concerns the right side of the head, the superior surface of the jugular process is more likely to be steep.

CONCLUSION

The jugular process forms the posteroinferior border of the jugular foramen. Resection of the jugular process is a critical step for opening the jugular foramen from the posterior and lateral aspects. Understanding the morphological features of the jugular process, and preoperative and radiographical examination of this process thus help skull base surgeons to access the jugular foramen.

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.

Microsurgical anatomy of the lateral condylar vein and its clinical significance

BACKGROUND

Although the lateral condylar vein has been encountered in some skull base approaches and used as a route to access the anterior condylar venous confluence, few descriptions can be found in the literature regarding its morphology.

OBJECTIVE

To examine the anatomy of the lateral condylar vein and its clinical significance.

METHODS

The craniocervical junctions of 3 cadaveric heads, 15 dry bones, and 25 computed tomography venography images were examined.

RESULTS

The lateral condylar vein was identified in 88.0% of paracondylar areas, with an average diameter of 3.6 mm. This vein originated near the jugular bulb, descended along the lateral surface of the occipital condyle and medial to the internal jugular vein, cranial nerves IX to XI, and rectus capitis lateralis muscle to drain into the vertebral venous plexus surrounding the vertebral artery. The veins were classified according to their origin from either (1) the anterior condylar confluence or (2) the internal jugular vein. In some specimens, the lateral condylar vein courses within a small osseous canal lateral to the occipital condyle, the paracondylar canal, which was identified in 16.7% of paracondylar areas in the dry bones.

CONCLUSION

The lateral condylar vein may be encountered in exposing the jugular bulb, hypoglossal canal, or foramen magnum. This vein has been reported to be a main draining route of dural arteriovenous fistulas, in which case it can be utilized as a transvenous route for endovascular treatment, or obliterated. An understanding of the anatomy of this vein may prove useful in planning skull base and endovascular procedures.

Lesions involving the jugular foramen: clinical characteristics and surgical management

CONCLUSION

Lesions involving the jugular foramen (JF) present as various diagnoses. Pulsatile tinnitus is more common in glomus jugulare (GJ) tumors, whereas otalgia and facial nerve paresis are more prevalent in temporal bone malignancies (TBMs). Preoperative facial nerve electroneurography (ENoG) was significantly correlated with postoperative facial nerve function.

OBJECTIVE

To describe the diagnosis and surgical management of lesions involving the JF.

METHODS

The charts were reviewed for 38 patients who had lesions involving the JF, including 14 patients with TBMs, 11 with GJ tumors, 7 with cholesteatomas, 2 with facial nerve schwannomas, 2 with JF schwannomas, and 2 with cholesterol granulomas. The follow-up data were recorded.

RESULTS

The most frequent symptoms included hearing loss (89.47%), followed by otorrhea (47.37%) and pulsatile tinnitus (39.47%). With respect to TBMs, 57.14% of patients complained of otorrhea and otalgia, and 50.00% presented with facial nerve paresis. Among the 13 patients with facial nerve paresis, 53.85% were diagnosed with TBMs. Regarding GJ tumors, 81.82% had pulsatile tinnitus and hearing loss. Among the 25 patients with normal preoperative facial nerve function, the mean facial nerve ENoG reduction was 29.48 ± 29.15%, and the mean postoperative facial nerve score was 77.48 ± 33.13. The correlation coefficient was -0.973 (p = 0.000).

Results of anterior facial nerve rerouting procedures for removing skull base tumors

OBJECTIVES

The purpose of this study was to estimate the rates of functional recovery of the facial nerve and of total tumor resection in patients who undergo short anterior rerouting and long anterior rerouting of the facial nerve in removal of skull base tumors.

METHODS

We retrospectively collected data on 37 patients with skull base tumors who underwent facial nerve rerouting during the procedure for tumor removal. Information on the rerouting technique, the completeness of tumor resection, and changes in facial nerve function were obtained from the medical records. Rerouting techniques were classified as short anterior rerouting or long anterior rerouting.

RESULTS

Ten of 16 patients (62.5%) in the group with short anterior rerouting showed postoperative facial palsy, and all completely recovered within 1 year. In the group with long anterior rerouting, 18 of 21 patients (85.7%) showed postoperative facial palsy, and recovery to a preoperative level of facial function was found in 10 patients at 1 year of follow-up. Total tumor resection was possible in 94% and 81% of patients with short rerouting and long rerouting, respectively. The mean operation time was not significantly related to the postoperative recovery of facial function.

CONCLUSIONS

Short rerouting techniques, when appropriately chosen on the basis of tumor and patient characteristics, offer excellent preservation of facial function and tumor resection, comparable to those of long rerouting techniques.

Stereotactic Radiosurgery of Cranial Nonvestibular Schwannomas: Results of Single- and Multisession Radiosurgery

BACKGROUND:

Surgical resection of nonvestibular cranial schwannomas carries a considerable risk of postoperative complications. Stereotactic radiosurgery (SRS) offers a non-invasive treatment alternative. The efficacy and safety of multi-session SRS of nonvestibular cranial schwannomas has not been well studied.

OBJECTIVE:

To analyze the results of single- and multi-session SRS of nonvestibular cranial schwannomas.

METHODS:

From 2001 to 2007, 42 lesions in 40 patients were treated with SRS at Stanford University Medical Center, targeting schwannomas of cranial nerves IV (n = 1), V (n = 18), VII (n = 6), X (n = 5), XII (n = 2), jugular foramen (n = 8), and cavernous sinus (n = 2). SRS was delivered to a median marginal dose of 18 Gy (range, 15-33 Gy) in 1 to 3 sessions, targeting a median tumor volume of 3.2 cm3 (range, 0.1-23.7 cm3). The median doses for treatments in 1 (n = 18), 2 (n = 9), and 3 (n = 15) sessions were 17.5, 20, and 18 Gy, respectively.

RESULTS:

With a median follow-up of 29 months (range, 6-84 months), tumor control was achieved in 41 of the 42 lesions. Eighteen of 42 lesions (43%) decreased in size; 23 tumors (55%) remained stable. There were 2 cases of new or worsening cranial nerve deficits in patients treated in single session; no patient treated with multi-session SRS experienced any cranial nerve toxicity (P = 0.18).

CONCLUSION:

SRS of nonvestibular cranial schwannomas provides excellent tumor control with minimal risk of complications. There was a trend towards decreased complications with multi-session SRS.

Severe progressive sensorineural hearing loss improved after removal of large jugular foramen schwannoma

We report a very rare case of hearing improvement after removal of the intracranial part of a jugular foramen schwannoma (JFS) presenting with chronic and severe progressive sensorineural hearing loss (SNHL). The patient presented with progressive hearing impairment in his right ear, lasting 2 years. The patient's pure tone audiogram revealed severe SNHL. His speech discrimination score (SDS) was 0%. Auditory-evoked brain responses (ABRs) comprised only I waves following 30-100dB stimulation, although distortion-product otoacoustic emissions (DPOAEs) had good responses. These test results indicated that his hearing impairment was retrocochlear SNHL. Magnetic resonance imaging revealed within the right jugular foramen a large intracranial-extracranial tumor that compressed the brainstem. The intracranial part of the tumor was resected through retrosigmoidal craniotomy, and the tumor was pathologically diagnosed as a schwannoma. Several months after the operation, the patient's auditory thresholds improved to a level consistent with mild SNHL, ABR V waves emerged following 60-90dB stimulation, and SDS improved significantly to 95%. This case demonstrates that hearing improvement can be achieved after surgery for JFS presenting with severe and chronic progressive SNHL, and that good DPOAE responses and the presence of ABR I waves may be predictors of postoperative hearing recovery in JFS.

Microsurgical management of 53 jugular foramen schwannomas: lessons learned incorporated into a modified grading system

OBJECT

Due to the proximity and involvement of critical neurovascular structures, the resection of jugular foramen schwannomas can pose a formidable challenge. The authors review their experience in the microsurgical management of jugular foramen schwannomas and propose a modified grading scale to guide surgical management.

METHODS

All jugular foramen schwannoma cases treated by the senior author (T.F.) between 1980 and 2004 were retrospectively reviewed. The average age at presentation, surgical approach, tumor characteristics, cranial nerve (CN) deficits, and tumor recurrence rates were assessed. The authors present the following modified grading scale: Type A, intradural tumors; Type B, dumbbell-shaped tumors; and Type C, triple dumbbell tumors with a high cervical extension.

RESULTS

The authors treated jugular foramen tumors in 129 patients during the study period. Of these, 53 patients (41%) had jugular foramen schwannomas. The mean patient age was 52 years (range 14-74 years); there were 12 male and 41 female patients. The mean follow-up period was 8.4 years. Patients presented most commonly with deficits of the vagus nerve, followed by vestibular/cochlear nerve and glossopharyngeal nerve deficits. Gross-total resection of the tumor was achieved in 48 patients (90.5%). New postoperative paresis in a previously normal CN was not seen; however, worsening of preoperative CN deficits was frequently noted. The highest incidence occurred with the glossopharyngeal and vagus nerves (30%), with 26% of the deficits being permanent. There were no deaths related to surgery in this series. Three patients (5.7%) experienced tumor recurrence.

CONCLUSIONS

The microsurgical resection of jugular foramen schwannomas carries a risk of worsening preoperative CN deficits; however, these are often transient. Based on their experience, the authors have formulated a grading scale that predicts the optimal surgical approach to these lesions. Considerable technical training and microneuroanatomical knowledge of the region is required. The modified grading scale presented facilitates preoperative planning.

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

The lateral surgical approach to jugular foramen schwannomas (JFS) may result in complications such as temporary facial nerve palsy (FNP) and hearing loss due to the complicated anatomical location. Ten patients with JFS surgically treated by variable methods of lateral approach were retrospectively reviewed with emphasis on surgical methods, postoperative FNP, and lower cranial nerve status. Gross total removal of the tumors was achieved in eight patients. Facial nerves were rerouted at the first genu (1G) in six patients and at the second genu in four patients. FNP of House-Brackmann (HB) grade III or worse developed immediately postoperatively in six patients regardless of the extent of rerouting. The FNP of HB grade III persisted for more than a year in one patient managed with rerouting at 1G. Among the lower cranial nerves, the vagus nerve was most frequently paralyzed preoperatively and lower cranial nerve palsies were newly developed in two patients. The methods of the surgical approach to JFS can be modified depending on the size and location of tumors to reduce injury of the facial nerve and loss of hearing. Careful manipulation and caution are also required for short facial nerve rerouting as well as for long rerouting to avoid immediately postoperative FNP.

Preservation of conductive hearing in approaches to tumors of the jugular foramen

OBJECTIVE

Surgical approaches to the jugular foramen, most often used for the resection of glomus jugulare tumors, may include removal of the external auditory canal wall and overclosure of the meatus, resulting in maximal conductive hearing loss. Modifications have been described that maintain hearing by preserving the canal wall at the price of decreased exposure and are, therefore, suitable only for small and favorably located tumors. Our technique for removal and then reconstruction of the canal wall with hydroxyapatite cement allows for complete anterior translocation of the facial nerve as far proximal as the geniculate ganglion, giving uncompromising exposure of even the most extensive tumors, with the potential for preservation of normal hearing. The purpose of this study was to describe and report our experience with this technique.

STUDY DESIGN

: Retrospective review.

SETTING

Private otology practice.

PATIENTS

Between 2000 and 2005, seven patients between the ages of 34 and 77 years were identified who underwent procedures using this technique.

INTERVENTION

Surgical management of jugular foramen tumors.

MAIN OUTCOME MEASURES

Successful anatomical reconstruction of the external auditory canal and middle ear. Preoperative and postoperative audiograms are compared, and facial nerve function is reported. Complications are discussed.

RESULTS

All seven patients had successful reconstruction of the external auditory canal. Complications were minor and did not require additional surgical intervention. Postoperative pure-tone average differed from the preoperative average by a mean of 7.5 dB. Facial nerve function ranged from House-Brackmann Grades I to III when checked at least 7 months after surgery.

CONCLUSION

This study reveals that this technique of external auditory canal reconstruction using hydroxyapatite cement allows complete anterior translocation of the facial nerve, while safely and reliably preserving the potential for normal hearing, without any compromise in exposure of the jugular foramen in the setting of an infratemporal fossa approach.

Transjugular Craniotomy for the Management of Jugular Foramen Tumors with Intracranial Extension

OBJECTIVES

To elucidate indications and outcomes with the transjugular craniotomy for resection of jugular foramen tumors with intracranial extension. The transjugular approach is a lateral craniotomy conducted through a partial petrosectomy traversing the jugular fossa combined with resection of the sigmoid sinus and jugular bulb, which often have been occluded by disease.

STUDY DESIGN

Retrospective review.

SETTING

University medical center.

PATIENTS

Twenty-eight patients with intracranial jugular foramen tumors who underwent a total of 30 surgical procedures.

MAIN OUTCOME MEASURES

Pathologic findings, surgical approach, extent of tumor resection, rate of facial nerve mobilization and ear canal closure, facial and lower cranial nerve outcomes, and hearing preservation.

RESULTS

Tumors included schwannoma (37%), meningioma (33%), glomus jugulare (23%), and chordoma (7%). The surgical approaches were tailored to maximize functional preservation, and included the transjugular (53%), translabyrinthine (17%), retrosigmoid (10%), and far lateral (7%) craniotomies. Translabyrinthine (3%) or transcondylarfar lateral (3%) approaches were occasionally used in combination with the trans-jugular approach. Most procedures were managed in a single stage (90%), but three patients with massive tumor in the neck required two stages. Microsurgical gross total and near-total tumor removal (37% each) were commonly achieved, although subtotal resections (27%) were occasionally performed. In only a minority of cases was facial nerve mobilization (7%) or ear canal closure (21%) required. If present preoperatively, Grade I facial nerve function was usually maintained (22 of 24 [92%]) and Hearing Class A or B could always be maintained (9 of 9 [100%]). As expected, new lower cranial nerve dysfunction was common (8 of 30 [27%]), although over half of the patients had complete lower nerve palsy preoperatively (16 of 30 [53%]).

CONCLUSION

Most patients with jugular foramen tumors with intracranial extension can be managed with a single-stage transjugular craniotomy. Facial nerve mobilization or ear canal closure is usually not required, permitting conservation of facial function and hearing, when present preoperatively.

Reversible cochleo-vestibular deficits in two cases of jugular foramen tumor after surgery

Primary jugular foramen (JF) tumor, such as glomus jugular tumor or JF schwannoma, may manifest as a lower cranial nerve deficit; in addition, it can be accompanied by deafness or vertigo if it affects the cranial nerve (CN) VIII. Recently, we encountered JF schwannoma 1 and glomus jugulare tumor 1. Both cases invaded the adjacent cerebellopontine angle, leading to cochleo-vestibular deficits prior to the operation. After surgery, recovery of the audiovestibular function, including hearing, auditory brainstem response and caloric response, was anticipated in both patients. Therefore, cochleo-vestibular deficits in JF tumors can be attributed to compression neuropathy, rather than tumor infiltration.