Selection of surgical approaches for meningiomas affecting the temporal bone

Meningiomas of the Internal Auditory Canal

OBJECTIVE

Identify and define specific preoperative and postoperative characteristics of intracanalicular meningiomas (ICMs) in order to improve their diagnosis and management, and to differentiate them from intrameatal vestibular schwannomas (IMVSs).

METHODS

Preoperative symptomatology, magnetic resonance imaging (MRI), and postoperative outcomes of 28 ICMs were analyzed. The results were compared to the literature and IMVSs treated by our group.

RESULTS

Anacusis and progressive hearing loss were more frequent in the present population than the cases reviewed (P = .0064 and P = .0001, respectively). Hearing loss affected more than 90% of the patients, with anacusis in 32.1% of the cases. Facial palsy affected 17.9% of the patients. In comparison to IMVSs, preoperative anacusis was more associated to meningiomas (P = .0037), and the facial nerve was more compromised in ICMs than IMVSs, both preoperatively (P = .0011) and at follow-up (P < .0001). According to a re-evaluation of preoperative MRIs and comparison with IMVSs, linear tumor borders, and linear morphology along the internal auditory canal wall, but not the presence of a dural tail, were significantly more present in ICMs (P = .0035, P = .0004, P = .1963, respectively). These characteristics could have led to a correct preoperative diagnosis in 61% of our cases.

CONCLUSION

Contrariwise to IMVSs, the frequent preoperative anacusis and facial palsy demonstrate the more aggressive nature of ICMs, which also carry a higher risk of postoperative facial palsy and difficulty to preserve hearing. An attentive evaluation of imaging should ease diagnosis, and asymptomatic or stable ICMs should be enrolled in a wait-and-scan protocol.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E413-E419, 2021.

Combined Transtemporal Access for Large (>3 cm) Meningiomas of the Cerebellopontine Angle

OBJECTIVES: Large meningiomas of the cerebellopontine angle present a formidable surgical challenge due to tumor vascularity, neural attachment, and brain stem compression. The purpose of this paper is to present our use of the combined transtemporal approach in the surgical treatment of 29 large meningiomas.

STUDY DESIGN AND SETTING: Twenty-nine patients with large meningiomas of the CPA were surgically treated through a combined retrosigmoid-transpetrosal-transcochlear approach at our tertiary care academic medical center from July 1995 through July 2004. Data was collected from a retrospective medical records review.

RESULTS: Total tumor removal was achieved in 19 of 29 (67%) of the patients and the facial nerve was anatomically preserved in 26 of 29 (89%) of the cases. Cerebrospinal fluid leakage was seen in 3.5% of the patients and additional transient cranial nerve deficits were noted in 14% of the cases, but no significant neurologic sequelae occurred. Of the 10 patients with residual tumor, 6 have been stable without growth, 2 were treated with reoperation for regrowth of disease, and 2 were controlled with localized radiotherapy.

CONCLUSIONS: This combined lateral transtemporal approach provided wide exposure to the cerebellopontine angle and optimized the surgical extirpation of 29 large meningiomas presented in this series.

Clinical characteristics and surgical outcomes of patients presenting with meningiomas arising predominantly from the floor of the middle fossa

BACKGROUND

Little is known regarding meningiomas that primarily arise from the floor of the middle fossa as opposed to the sphenoid wing, the cavernous sinus, the anterior petrous ridge, or the lateral convexity dura.

OBJECTIVE

Given the relative paucity of literature addressing this disease entity, we review the University of California at San Francisco (UCSF) experience with these tumors.

METHODS

Between 1991 and 2006, 1228 patients were seen by neurosurgeons at UCSF for meningiomas of which 17 (1.1%) patients met our criteria for a "middle fossa floor" meningioma, of which 15 underwent first-time surgery and were included in this series. The most common presenting symptoms were headache (9 patients), seizures (6 patients), trigeminal nerve dysfunction (5 patients), hearing loss (5 patients), gait disturbance (5 patients), and cognitive decline (3 patients). All patients underwent surgical resection via frontotemporal craniotomy, with or without orbitozygomatic osteotomy.

RESULTS

We were able to achieve a Simpson grade 1 or 2 resection in 10 of 15 patients (67%). The operative morbidity was clustered in 5 patients, as 10 of 15 patients (67%) experienced no operative morbidity. There were 4 known clinical recurrences in this group at 5 years median follow-up. All patients had either higher grade tumors, or received a Simpson grade 3 or higher resection.

CONCLUSION

We present the clinical characteristics and surgical outcome of a series of patients presenting with meningiomas primarily arising from the concave floor of the middle cranial fossa. Given the relatively uncommon nature of these lesions, more investigation into the clinical behavior of this entity is warranted.

Temporal bone meningiomas

Meningiomas involving the temporal bone may originate from arachnoid cell nests present within the temporal bone (intratemporal), but more frequently originate from arachnoid cell nests of the posterior or middle cranial fossa with secondary invasion of the TB (extratemporal). In this study, we retrospectively reviewed the charts of 13 patients with meningiomas involving the temporal bone who underwent surgery. Tumors of the posterior fossa with only temporal bone hyperostosis, but without invasion, were excluded. Patients presented primarily with otologic symptoms and signs. The tumors originated in the temporal bone (5/13), jugular foramen (4/13), petroclival region (2/13), the asterion (1/13) or the internal auditory meatus (1/13). All of the intratemporal meningiomas had the radiological appearance of en-plaque menigiomas. The tumor extended into the middle ear (11/13), eustachian tube (5/13), and/or the labyrinth (3/13). A gross total resection was achieved in 11 patients and a subtotal resection in 2 patients. The lower cranial nerves were infiltrated by tumor in 4 patients, and were sacrificed. At a mean follow-up of approximately 6 years, 12 patients are currently alive and doing well and 1 died from tumor progression. Six patients showed tumor recurrence and were reoperated on (5/6) or followed conservatively (1/6). Surgical treatment of temporal bone meningiomas is associated with high recurrence rate due to indiscreet tumor margins. Combined surgical approaches (temporal craniotomy and mastoidectomy) by neurosurgical and otological teams are recommended for meningiomas originating in the temporal bone.

Applications of image-guided navigation in the middle cranial fossa: an anatomic study

Determining the location of pertinent anatomic structures (ie, the internal auditory canal [IAC]) in middle cranial fossa surgery is commonly based on indirect inferences from bony landmarks. Several methods have been proposed for identification of the IAC, each using bony landmarks coupled with geometric formulation. Identification of the IAC based on bony architecture and geometry may be severely limited when a mass lesion is present. Image-guided surgery has the advantage of rapid localization and may be helpful in navigating a complex surgical field which has been distorted by tumor. This study evaluates the feasibility and accuracy of the ISG viewing wand in determining pertinent anatomic landmarks in the middle fossa of the human cadaver. High-resolution (1 mm) computed tomography was performed on a preserved human cadaver head in which fixed fiducial markers had been placed. Subsequently, the cadaver head was registered in a simulated operative field, and middle fossa craniotomy was performed. The foramen spinosum, foramen ovale, greater superficial petrosal nerve, internal carotid artery, arcuate eminence, and IAC were identified visually, and three independent localizations of each structure were performed with the viewing wand. Accurate localizations were consistently performed within 1 mm for each anatomic landmark. Image-guided navigation is both feasible and accurate in determining intraoperative landmarks in the middle fossa. Image-guidance may enhance surgical accuracy and efficiency. Further clinical studies evaluating image-guided techniques in the middle fossa are warranted.

Posterior fossa meningioma: surgical strategy

Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far.

Combined Petrosal Approaches in the Management of Temporal Bone Meningiomas

OBJECTIVES

To evaluate the indications and outcomes of the combined petrosal approaches in the surgical management of temporal bone meningiomas.

STUDY DESIGN

Retrospective chart review.

SETTING

University teaching hospital.

PATIENTS

Adults with temporal bone meningiomas.

INTERVENTION(S)

Meningioma removal using a combined petrosal approach.

MAIN OUTCOME MEASURE(S)

Cranial nerve outcomes, complications, completeness of resection, and recurrence rates.

RESULTS

Forty-nine patients underwent surgical excision of a temporal bone meningioma between 1996 and 2004 at our institution. Nineteen of these patients required a combined petrosal approach for excision. The most common presenting complaints were balance disturbance, 11 (58%); hearing loss, 10 (53%); headache, 10 (53%); and tinnitus, 9 (47%). The most common tumor origin was of the petrous ridge (14; 74%). Average tumor size was 3.1 cm. Complete resection was possible in 17 (89%) patients. Upper cranial nerve (III-VI) function was improved in two (11%) patients and worsened in three (16%) patients. Lower cranial nerve (IX-XII) function improved in one (5%) patient and was worsened in one (5%) patient. Postoperative facial nerve function was Grades I to II in 16 (84%) patients and Grades III to IV in 1 (5%) patient at last follow-up. Hearing data were available in 14 patients. Of those patients, 11 (85%) had serviceable hearing after surgery. The most common surgical complication was a cerebrospinal fluid leak, with three (16%) incidences. There were no reported incidents of stroke, death, or meningitis in the cohort.

CONCLUSION

The use of the combined petrosal approach for temporal bone meningioma resection results in favorable outcomes for the patient. The incidence of complications is acceptably low, and cure rates are high.

The challenges of revision skull base surgery

Because the skull base is an anatomically complex structure, skull base tumors can hide easily in the crevices that interconnect the intra- and extracranial spaces and intermingle with important neurovascular structures. Often, total surgical resection of these tumors is not possible, and even with postoperative adjuvant radiotherapy, some recurrences after treatment are inevitable. Early detection of recurrent skull base tumors requires clinical vigilance and periodic imaging studies. The management of recurrent skull base tumors presents many challenges beyond those associated with primary procedures. A multidisciplinary setting that includes modern microsurgery and stereotactic radiation therapy provides patients with optimal care.

Retrolabyrinthine craniectomy: the unsung hero of skull base surgery

Despite being the foundation of, or supplement to, many skull base exposures, the retrolabyrinthine approach has not been adequately illustrated in the skull base literature. As an aid to skull base surgeons in training, this article provides a step-by-step description of the microsurgical anatomy and operative nuances of this important technique.

Facial Nerve Rerouting in Skull Base Surgery

Facial nerve rerouting techniques were developed to facilitate re-section of extensive tumors occupying the skull base. Facial nerve rerouting has its own limitations and risks, requiring microsurgical expertise, additional surgical time, and often some degree of facial nerve paresis. This article presents different degrees of anterior and posterior facial nerve rerouting, techniques of facial nerve rerouting, and a comprehensive review of outcomes. It then reviews anatomic and functional preservation of the facial nerve in acoustic neuroma resection, technical aspects of facial nerve dissection, intracranial facial nerve repair options, and outcomes for successful acoustic neuroma surgery.

The evolution of surgical approaches for posterior fossa meningiomas

OBJECTIVE

To evaluate surgical outcomes for the treatment of posterior fossa meningiomas at the House Ear Clinic from 1987 to 2001. We review our current treatment algorithm and present our postoperative outcomes with attention to facial and auditory neural preservation.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary care center.

PATIENTS

Medical records of 71 patients who underwent posterior fossa meningioma surgery at the House Ear Clinic were reviewed.

INTERVENTION

All patients had surgical removal of their meningioma via translabyrinthine, transcochlear, retrosigmoid, extended middle fossa, or combined petrosal approaches by House Ear Clinic neurotologists and neurosurgeons.

MAIN OUTCOME MEASURES

Preoperative and postoperative auditory and facial nerve function data were collected. Patient and tumor characteristics including presenting symptoms, completion of tumor resection, and complications secondary to surgery were also recorded.

RESULTS

The most common presenting symptoms in this series were otologic, with hearing loss (61%), tinnitus (58%), and imbalance (58%) as the three most common. Gross total resection was achieved in 67 (94%) patients. Hearing-preservation surgery was attempted in 37 (52%) patients (68% via extended middle fossa or combined approach). Twenty-one patients with preoperative Class A hearing had follow-up audiometric data and 18 (86%) had serviceable hearing preserved. Excluding transcochlear craniotomies, 85% of patients had normal facial nerve function postoperatively. Cerebrospinal fluid leak (6%) was the most common complication.

CONCLUSIONS

Advances in microsurgical techniques have greatly changed our management of patients with posterior fossa meningiomas. These changes have reduced postoperative morbidity. Specifically, use of the anterior and posterior petrosal approaches has facilitated facial and auditory neural preservation while not compromising the extent of tumor excision.

Meningiomas of the posterior petrous bone: functional outcome after microsurgery

OBJECT

The aim of this study was to analyze a subgroup of patients harboring cerebellopontine angle meningiomas originating from the posterior petrous bone in regard to clinical presentation, surgical anatomy, complications, and long-term functional postoperative results.

METHODS

Data in a series of 51 patients with meningiomas of the posterior petrous bone who had undergone microsurgical treatment at the authors' institution between 1989 and 2002 were retrospectively reviewed. The patient population consisted of 46 women and five men with a mean age of 53 years (range 22-70 years). The main symptom on first admission was impaired hearing in 41%, dizziness in 20%, and tinnitus in 18% of the patients. Results of physical examination and audiological testing revealed hypacusis in 65% of patients, cerebellar ataxia in 31%, and impairment of the fifth cranial nerve in 26%. All patients underwent surgical treatment via a lateral suboccipital approach. Intraoperatively, the tumor was found to be attached to the postmeatal dura in 37%, the premeatal dura in 27.5%, the suprameatal dura in 19.6%, the inframeatal dura in 7.8%, and centered on the porus acusticus in 5.9% of cases. Tumor extension into the internal acoustic meatus was present in seven patients. Tumor resection was categorized as Grade I in 14 patients, Grade II in 29, Grade III in six, and Grade IV in two patients, according to the Simpson classification system. The site of displacement of the cranial nerves was predictable in up to 84% of patients, depending on the dural origin of the tumor as depicted on preoperative magnetic resonance (MR) imaging studies. Postoperatively, a new and permanent facial paresis was observed in five patients (9.8%). In 38 patients in whom both pre- and postoperative audiological data were available, hearing function deteriorated after surgery in 18.4% and improved in 7.9%. Clinical and MR imaging postsurgical data from a mean period of 5.8 years (range 13 months-13 years) were available in all patients. Forty-four patients (86%) resumed normal daily activity. Tumor recurrence was observed in two patients (3.9%), and both underwent a second surgery.

CONCLUSIONS

Preoperative detailed analysis of MR imaging data gives the surgeon a clue about the dislocation of critical neurovascular structures, particularly the cranial nerves. Nonetheless, the exact relationship of the cranial nerves to the tumor (dislocation, adherence, infiltration, and splaying of nerves) can only be fully appreciated during surgery.

Meningioma of the Jugular Foramen: Glomus Jugulare Mimic and Surgical Challenge

OBJECTIVES

Meningiomas involving the jugular foramen are rare lesions, with approximately 34 cases reported in the English literature. Clinically, these tumors mimic the more common glomus jugulare tumor. After surgical resection, meningiomas have worse cranial nerve outcomes and higher recurrence rates than glomus tumors. There is controversy regarding the selection of surgical approach, particularly with regard to management of the facial nerve. A reliable means of accurate preoperative diagnosis would help surgical planning and patient counseling.

STUDY DESIGN

We present a series of six consecutive large jugular foramen meningiomas resected by a single surgeon from 1996 to 2002.

METHODS

Retrospective case series (chart review).

RESULTS

The preoperative diagnosis was correct in nearly all (6/7) cases on the basis of the characteristic imaging findings seen with a combination of temporal bone dedicated computed tomography and high-resolution enhanced magnetic resonance imaging. Five of six patients had lateral facial nerve rerouting (infratemporal fossa Fisch type A), and three patients also had posterior rerouting (transcochlear approach with division of greater superficial petrosal nerve). Total tumor removal was accomplished in 83%. One patient suffered recurrence over a mean follow-up period of 2.5 years. New postoperative vocal cord palsies occurred in 50% of patients, and all required vocal cord medialization. At 1 year, 50% of patients had normal or near normal (House-Brackmann I or II) facial function. Postoperative cerebrospinal fluid leaks occurred in two patients, and both eventually required ventriculoperitoneal shunts.

CONCLUSIONS

Meningiomas involving the jugular foramen are surgically challenging tumors that pose unique diagnostic issues. The majority of these lesions can be completely resected. A relatively high postoperative complication rate, which can be controlled with appropriate intervention, is seen with these surgeries.

Anterior and Posterior Facial Nerve Rerouting: A Comparative Study

The infratemporal fossa type A (IFT-A) and the modified transcochlear approach are used to remove glomus jugular tumors type C and petroclival tumors extending to the prepontine cistern, respectively. Anterior rerouting is a key step in IFT-A, whereas the modified transcochlear approach involves posterior rerouting. The aim of this study was to analyze facial nerve function after application of the two procedures. One year after surgery, anterior rerouting was associated with excellent to good outcomes (grade I to III) in 94 % of the cases, while posterior rerouting was associated with good outcomes (grade III) in 70 % of the cases.

Meningiomas of the cerebellopontine angle. A report of 41 cases

A retrospective study of the surgical management of 41 cerebellopontine angle (CPA) meningiomas was performed. All patients were treated by a single surgeon (TTK) over a 25 year period (1967-1992). There were 13 males, 28 females with a median age of 53.5 years. The median follow-up after surgery was 9 years (range 2-20.4 years). Tumours were classified anatomically into six groups (lateral, midpetrosal, petroclival, internal auditory meatal, Meckel's cave and inferior). Only the petroclival tumours posed difficulties with complete resection (achieved in 7 out of 16) and for most of them a transtentorial transpetrous approach was used. In other groups, complete resection was achieved in all patients. There were four recurrences (two mid-petrosal, one petroclival, one internal auditory meatal), three of which had complete macroscopic resection at the initial operation.

Preoperative and Postoperative Auditory and Facial Nerve Function in Cerebellopontine Angle Meningiomas

Preoperative and postoperative facial nerve and auditory function were reviewed retrospectively in 13 cases of cerebellopontine angle meningiomas. According to their location within the posterior fossa and with special reference to the internal auditory canal, they were classified into a premeatal and a retromeatal group. All the tumors were removed by an otoneurosurgical team by use of a retrosigmoid approach. Postoperative results (1 year after operation) were compared within the two groups with respect to preservation of hearing (normal hearing in 31% and preservation of preoperative hearing in 69% of the cases) and facial nerve function (no or mild postoperative impairment in 69% of the cases). Both preoperative and postoperative impairment of facial nerve and auditory function prevailed in the premeatal group. For preservation of vital vascular and central nervous structures, subtotal resection with consecutive fractionated radiation therapy had to be performed in 30% of the cases. Our results provide substantial evidence that in cerebellopontine angle meningiomas a precise preoperative study of tumor location will assist in improving individual operative strategy and thus postoperative functional results.