Posterior petrous meningiomas: 82 cases

OBJECT: The aim of this study was to discuss posterior petrous meningiomas--their classification, clinical manifestations, surgical treatments, and patient outcomes. METHODS: A retrospective analysis was performed in 82 patients with posterior petrous meningiomas for microsurgery. According to the anatomical relationship with the posterior surface of the petrous bone and with special reference to the internal auditory canal (IAC), posterior petrous meningiomas were classified into three types: Type I, located laterally to the IAC (28 cases); Type II, located medially to the IAC, which might extend to the cavernous sinus and clivus (32 cases); and Type III, extensively attached to the posterior surface of the petrous bone, which might envelop the seventh and eighth cranial nerves (22 cases). Sixty-eight (83%) of 82 cases involved total resection. The rate of anatomical preservation of facial nerve was 97.5%, whereas the functional preservation rate was 81%. The rate of hearing preservation was 67%. All Type I tumors were completely resected, and the rate of anatomical preservation of facial nerve was 100% and functional preservation was 93%. Regarding Type II lesions, 75% of 32 cases involved total resection; the rate of anatomical preservation of facial nerve was 97% and functional preservation was 75%. For Type III lesions, 73% of 22 cases were totally resected. The rate of anatomical preservation of facial nerve in patients with this tumor type was 95%, whereas functional preservation was 73%. CONCLUSIONS: Clinical manifestations and surgical prognoses are different among the various types of posterior petrous meningiomas. It is more difficult for Types II and III tumors to be resected radically than Type I lesions, and postoperative functional outcomes are significantly worse accordingly. The primary principles in dealing with this disease entity include preservation of vital vascular and central nervous system structures and total resection of the tumor as much as possible.     

Microsurgical removal of petroclival meningiomas: a report of 33 patients.

This is a report of 33 consecutive cases of petroclival meningioma treated surgically at our institution over the last 10 years; there were 21 women and 12 men between the ages of 27 and 68 (mean age, 52). All patients were assessed by computed tomographic scans including coronal sections and bone algorithm studies; in most cases, digital subtraction angiography and magnetic resonance imaging were also done. The largest tumor diameter was between 2 and 3.5 cm in 14 cases, 3.5 to 6 cm in 15 cases, and over 6 cm in 4 cases. Dural attachment predominantly involved the clivus and apical petrous bone on one side only; in 14 cases, however, the tumor grew over the clivus midline or crossed the tentorial notch. Cranial nerve deficit was extant in all cases and was commensurate with tumor size. Cerebellar signs and somatic motor deficits were present in 60 and 30% of cases, respectively. The surgical approaches used were the retromastoid-retrosigmoid in 23 cases, subtemporal in 5 cases, and combined retromastoid subtemporal presigmoid in the remaining 5. Total removal was achieved in 26 cases (79%); incomplete removal occurred in 7 cases (21%). The extent of tumor removal and operative morbidity were not significantly related to tumor size. Brain stem indentation, arterial and cranial nerve encasement, and epidural invasion were the main factors that prevented total tumor removal and influenced operative morbidity. There was no intraoperative mortality, but three patients (9%) died perioperatively. In the postoperative period, most patients went through momentary neurological deterioration, chiefly due to new cranial nerve deficits. The average follow-up was 4.3 years in 27 patients; of these 17 were unchanged and 10 were improved. Before surgery, only 13 patients were self-sufficient; at long-term follow-up, another 6 had achieved independence. Our experience suggests that, even though real petroclival meningiomas still represent a formidable surgical challenge, such tumors can in most cases be removed completely with low attendant mortality and acceptable morbidity.     

Combined petrosal approach to petroclival meningiomas

OBJECTIVE: To study the use and advantages of combining the posterior petrosal approach with the anterior petrosal approach to petroclival meningiomas. METHODS: Seven cases of petroclival meningiomas operated on via the combined petrosal approach were retrospectively analyzed. The basis on which this approach was selected was assessed, as were its benefits and risks. RESULTS: Gross total resection was achieved in five of the seven patients. No mortality or decrease in Karnofsky performance score was observed at the time of the last follow-up examination. Six of the seven patients had serviceable hearing before the operation. Only one patient lost hearing after the operation, and this hearing loss occurred in only one ear. Before the operation, six patients were House-Brackmann facial nerve function Grade I, and one patient was Grade II to III. At the last follow-up examination, facial nerve function was Grade I in five patients, Grade II in one patient, and Grade V in one patient. Tumors in all patients involved the cavernous sinus, Meckel's cave, petroclival junction, and middle clivus. All patients possessed a large posterior fossa component of tumor measuring an average of 3.6 x 3.5 x 4.2 cm. In four patients, the tumor was attached for the entire width of the clivus to the contralateral petroclival junction. Four patients displayed central brainstem compression. Four patients displayed bony changes at the petrous apex. All patients displayed total or partial encasement of the vertebrobasilar artery and its major branches. CONCLUSION: The combined petrosal approach should be considered for patients who have a large petroclival meningioma and serviceable hearing. This approach enhances petroclival exposure and the degree of tumor resection, especially in the area of the petroclival junction, middle clivus, apical petrous bone, posterior cavernous sinus, and Meckel's cave. The combined petrosal approach also allows better visualization of the contralateral side and the ventral brainstem, which facilitates safe dissection of the tumor from the brainstem, the basilar artery, and the perforators. If a patient has an early draining bridging vein to the tentorial sinus (before it reaches the transverse-sigmoid junction) or a prominent sigmoid sinus and jugular bulb, the combined petrosal approach provides significant working space.     

Clivus and apicopetroclivus meningiomas--report of 24 cases

The authors describe the clinical and radiological features, surgical procedures, and outcome of 18 cases of clivus meningiomas and six of apicopetroclivus meningiomas. There were 17 females and seven males, ranging in age from 26 to 69 years, with a mean age of 47 years. All except one showed cranial nerve deficits. Computed tomography accurately demonstrated tumor size and location. Cerebral angiography showed characteristic displacement of the basilar artery and its tributaries, with blood supply to the tumor largely via the meningohypophyseal trunk. Magnetic resonance imaging was excellent in delineating the relationship of the tumor to the brainstem and major vasculature. The surgical approaches used were transpetrosal-transtentorial (n = 9), combined transpetrosal-transtentorial-transzygomatic preauricular transpetrosal (n = 9), suboccipital-subtemporal (n = 2), suboccipital (n = 1), frontotemporal (first stage operation) followed by suboccipital (second stage operation) (n = 1), suboccipital-transpetrosal (n = 1), and orbitozygomatic-infratemporal preauricular transpetrosal (n = 1). Seventeen tumors were totally removed and seven subtotally. The operative mortality was 8% (two patients). Twenty patients developed new cranial nerve deficits within 1 month of surgery. The average follow-up period was 5 years, and the outcome was good or excellent in 12 cases. Transpetrosal approaches proved relatively safe and effective for radical tumor removal and, in two cases, permitted preservation of useful hearing.(ABSTRACT TRUNCATED AT 250 WORDS)     

Combined approach for lesions involving the cerebellopontine angle and skull base: experience with 20 cases--preliminary report.

Skull base tumors involving the clivus, petrous bone, and adjacent areas can be formidable lesions to successfully remove without causing significant neurologic deficits. At our institution in the last 5 years, twenty patients out of 103 patients with skull base tumors have undergone the supratentorial-infratentorial combined approach for removal of a neoplasm (nine schwannomas, six meningiomas, two epidermoids, one extensive basal cell carcinoma, one pontine cavernous malformation, and one basilar artery aneurysm). The average patient age was 43 years. The combined approaches in conjunction with the subtemporal exposure were retrosigmoid-retrolabyrinthine, retrosigmoid-translabyrinthine, or retrosigmoid-transcochlear. The choice depended upon the type and location of the lesion and the deficits noted preoperatively. Basically, the approach allowed communication of the middle fossa and posterior fossa by totally dividing the tentorium as much as necessary for effective surgical manipulations. Both sigmoid and superior petrosal sinuses are divided. There were no deaths. Postoperative neurologic deficits included temporary seventh nerve paralysis, sixth nerve weakness, fifth nerve sensory deficits, cerebrospinal fluid leaks, and hydrocephalus requiring a shunt. Overall, the results were very gratifying, considering the difficulties encountered in the surgical removal of these lesions.     

Conventional posterior fossa approach for surgery on petroclival meningiomas: a report on an experience with 28 cases

BACKGROUND: This is a report of our experience with 28 cases of select petroclival meningiomas operated by a posterior fossa route encompassing the lateral supracerebellar-infratentorial and retrosigmoid avenues. METHODS: Twenty-eight cases of petroclival meningiomas treated during the period 1991 to 2002 by conventional posterior cranial fossa route are analyzed. The average length of follow-up is 48 months. RESULTS: The maximum diameter of the tumors ranged from 1.8 to 6.8 cm (mean, 4.0 cm). Five tumors extended up to or beyond the contralateral petroclival junction. Basilar artery was at least partially encased in 9 cases. Gross total tumor resection was achieved in 21 cases and a partial tumor resection was achieved in the remaining 7 cases. Two patients died in the postoperative phase. CONCLUSIONS: Conventional posterior cranial fossa surgery can be suitable for a select group of petroclival meningioma. Apart from other advantages, it provides easy and quick exposure of the tumor without any petrous bone drilling. It also provides a direct and early exposure of the tumor-cranial nerve-brainstem interface facilitating the dissection. The lateral and inferior tumor extensions in relationship to the clivus can be more easily accessed. The site of attachment of the tumor to the dura overlying the posterior face of the petrous apex can be seen directly.     

Combined subtemporal and retrosigmoid keyhole approach for extensive petroclival meningioma surgery: report of experience with 7 cases.

OBJECTIVE: Resection of petroclival meningiomas offers great challenges to the neurosurgeons. Our experience of 7 cases using a combined subtemporal and retrosigmoid keyhole approach surgery was evaluated for the treatment of extensive petroclival meningiomas. METHODS: From July 2002 to July 2005, resections of 7 petroclival meningiomas, which involved both supra- and infratentorial regions, were performed via a combined subtemporal and retrosigmoid keyhole approach. The extent of tumor resection was evaluated by MRI 3 months after surgery, and postoperative complications were investigated. RESULTS: The maximum diameter of the tumors ranged from 3.4 to 6.0 cm (mean: 4.4 cm). Gross total resection (GTR) was achieved in 3 cases, giving a GTR rate of 43%. Subtotal resection (STR) was carried out in 4 cases. Neurological status remained intact in one case, while others presented with cranial nerve deficits (VII, VI, V, III and lower CN). No death was reported in the cases during the postoperative period. CONCLUSION: The combined keyhole approach is suitable for the treatment of extensive petroclival meningiomas. It provides easy and quick access to the supra- and infratentorial juxtaclival region without any petrous bone drilling. Complications related to the approach can be minimized.     

Temporomandibular joint-preserving preauricular subtemporal-infratemporal fossa approach: surgical technique and clinical application

OBJECTIVE: The preauricular subtemporal-infratemporal (PSI) approach is commonly used to resect clival tumors and other lesions anterior to the brainstem. One of the surgical steps in this approach is a condylar osteotomy or a condylectomy, which often leads to temporomandibular joint dysfunction. We describe a modification of the PSI approach that preserves the temporomandibular joint without sacrificing the ability to mobilize the petrous internal carotid artery or gain surgical access to the clivus and anterior brainstem. METHODS: Anatomic studies in cadaveric specimens were performed, and the extent of exposure of critical skull base and intradural structures was documented with postdissection fine-cut computed tomographic scans. This modification of the PSI approach was subsequently used in three consecutive patients with a clival chondrosarcoma, and the completeness of tumor resection was documented with postoperative magnetic resonance imaging and computed tomographic scans. RESULTS: This approach allowed complete mobilization of the petrous internal carotid artery and surgical access to the mid-lower clivus, jugular tubercle, hypoglossal canal, occipital condyle, anterior brainstem, and the origin of the trigeminal through hypoglossal nerves. It also proved to be safe and feasible in the three patients who underwent surgical resection of a clival chondrosarcoma, allowing a complete tumor removal. CONCLUSION: This variation of the PSI approach is practical, has no additional morbidity, and provides complete access to critical cranial base regions and tumor margins. It can certainly be used as an alternative to the standard PSI approach when dealing with clival tumors and other lesions anterior to the brainstem.     

Combined subtemporal and retrosigmoid keyhole approach for extensive petroclival meningiomas surgery: report of experience with 7 cases.

OBJECTIVE: The resection of petroclival meningiomas offers great challenges to the neurosurgeon. Surgery via a combined subtemporal and retrosigmoid keyhole approach surgery was evaluated for the treatment of extensive petroclival meningiomas on the basis of our experience with 7 cases. METHODS: From July 2002 to July 2005, the resections of 7 petroclival meningiomas, which involved both supra- and infra-tentorial regions, were performed via a combined subtemporal and retrosigmoid keyhole approach. The extent of tumor resection was evaluated by MRI 3 months after surgery, and postoperative complications were investigated. RESULTS: The maximum diameter of tumors ranged from 3.4 to 6.0 cm (mean: 4.4 cm). Gross total resection (GTR) was achieved in 3 cases, giving a GTR rate of 43%. Subtotal resection (STR) was carried out in 4 cases. Neurological status remained intact in one case, while the others presented with cranial nerve deficits (VII, VI, V, III and lower CN). No death was reported during the postoperative period. CONCLUSION: This combined keyhole approach is suitable for the treatment of extensive petroclival meningiomas. It provides easy and quick access to the supra- and infratentorial juxta-clival regions without any petrous bone drilling. Complications related to the approach can be minimized.     

Meningiomas involving the optic nerve: technical aspects and outcomes for a series of 50 patients

OBJECTIVE: Surgical strategies and results for 50 patients with meningiomas involving the optic nerves are discussed and evaluated. Factors affecting the degree of resection and patient outcomes are presented. We emphasize our surgical techniques for resection of these tumors and we discuss the advantages of different approaches, depending on the relationship of the tumor to the optic nerves. METHODS: Data for 50 patients with meningiomas involving the optic nerves who were surgically treated between 1991 and 2002 were reviewed, by using patient files, operative notes, and pre- and postoperative imaging and ophthalmological examination findings. RESULTS: Thirty-one female patients and 19 male patients, with a mean age of 53 years, were treated. Thirty-one patients (62%) underwent complete tumor removal (Simpson Grade 1 or 2), and 19 patients underwent subtotal removal (Grade 4). Factors affecting the grade of resection were tumor size (P = 0.01), location (P = 0.007), and internal carotid artery encasement (P = 0.019). Patients who underwent Grade 1 or 2 resection exhibited a mean tumor size of 3.0 cm, and patients who underwent Grade 4 resection exhibited a mean tumor size of 4.1 cm. Only three patients had residual tumor on the optic nerve; all others had tumor in the cavernous sinus or at the orbital apex or exhibited vascular involvement. Visual outcomes were influenced predominantly by tumor size, preoperative visual function, and optic nerve encasement. CONCLUSION: Meningiomas that involve the optic nerves require special considerations and surgical techniques. Early decompression of the optic nerve within the bony canal allows identification and separation of the tumor from the nerve, permitting removal of the tumor from this area with minimal manipulation of the optic nerve.     

Nation-wide Brain Tumor Registry-based Study of Intracranial Meningioma in Japan: Analysis of Surgery-related Risks

Although surgical resection is the most preferred treatment for intracranial meningiomas, a detailed analysis of the surgery-related risks based on large population data has not been conducted to date. In this study, we analyzed the nation-wide brain tumor registry to assess the surgical risk factors for intracranial meningiomas to provide information for an optimal treatment strategy. Data of 4081 meningioma patients who underwent initial resection between 2001 and 2008 were extracted from the Brain Tumor Registry of Japan (BTRJ) database and reviewed for postoperative mortality, aggravation of Karnofsky Performance Score (KPS), and complications. The total in-hospital mortality rate was 0.59%. Male sex and tumor size ≥30 mm were independent risk factors for mortality. Among 4081 cases, 4.4% of patients had KPS that were lowered by 20 or more points at the time of discharge after surgery. Age ≥65 years, higher WHO grading, tumor location at the skull base, tumor size ≥30 mm, and non-gross total resections were associated with lowering of KPS scores by 20 or more points. The overall incidence of surgical complications was 19.3%. The rate of occurrence of new postoperative seizure in patients with supratentorial meningioma was 10.9%. All complications except for vascular complications occurred with significantly lower frequencies in asymptomatic patients than in symptomatic patients. Our results provide useful information regarding the surgical risks when surgical intervention is being considered for intracranial meningiomas. Surgery is an important option for asymptomatic meningiomas as the mortality rate and complication rate in the current study were sufficiently low.     

Tentorial meningiomas: follow-up review

Tentorial meningiomas comprise 3-5% of the intracranial meningiomas. Different locations and sinus invasion require special surgical skills. This study aimed to analyze factors influencing the outcome of 29 patients (30 tumors) with tentorial meningiomas surgically treated. The study included 22 female and seven male patients, with age of 18-76 years old, and a follow-up of 6-179 months. Eight tumors were located on the inner tentorial ring, 15 on the outer ring, four were falcotentorial, and three attached/invading the torcula. Outcome was analyzed using survival and recurrence-free survival (RFS) curves. Twenty-seven tumors were WHO grade I and three were grades II-III. Total and subtotal resections were reached in 87.5% and 12.5% of tumors. Survival was better for patients with grade I tumors and similar according to sex, location, size, and extent of resection. Recurrence/regrowing rate was 12.5%. RFS curves were better for patients with grade I or with radical resection and similar according to sex, location, and size. There was no operative mortality. Permanent postoperative cranial nerve deficits occurred in 9.7% (all inner ring tumors). Despite being many times large-sized, surgical treatment of tentorial meningiomas gives good results. Prognostic factors for recurrence were histopathologic grade III and subtotal resection. Radical resection allowed better results. Nevertheless, subtotal resection may be acceptable for cases with cranial nerves or sinuses invasions.     

Clear cell meningioma of the cauda equina in an adult: case report and literature review

In the pediatric population, clear cell meningiomas are more frequently intracranial than intraspinal in location. Tumors recur in up to 40% of cases within 15 postoperative months and are often managed with repeated resection with or without radiation therapy. The management strategy for adults with clear cell meningiomas involving the lumbar spinal canal (cauda equina) is less clearly defined. A 41-year-old woman presented with mild, right greater than left, lower extremity paresis. An enhanced magnetic resonance (MR) scan revealed a homogeneously enhancing intradural lesion filling the spinal canal at the L3-L4 level. Preoperative noncontrast MR studies of the brain and cervical and thoracic spine were negative. An L2-L5 laminectomy was performed for gross total excision of the intradural lesion, which was adherent to one nerve root of the cauda equina. Frozen-section diagnosis confirmed clear cell tumor. Differential diagnoses included meningioma versus renal cell carcinoma. Negative postoperative chest, abdominal, and pelvic computed tomography studies ruled out tumor of renal cell origin. Enhanced MR studies of the neuraxis proved negative. Consultations with multiple oncologists and radiation therapists recommended neither radiation nor chemotherapy following this initial surgery. She remains disease-free 1 year postoperatively. The high recurrence rate for clear cell meningiomas in children requires repeated tumor resection with or without secondary radiation therapy. Following gross total resection of lumbar tumors in adults, reserving radiation therapy for secondary recurrences provides optimal management.     

Combined approach for lesions involving the cerebellopontine angle and skull base: experience with 30 cases

This article presents a series of 30 patients who underwent a combination of the subtemporal and posterior fossa approaches for exposure of lesions in the clivus or medial petrous region. This combined supra- and infratentorial approach is divided into three variations with progressively greater petrous bone resection to increase exposure of the clivus and medial petrous region. The approach has been divided into petrous bone resection with preservation of hearing (retrolabyrinthine), greater petrous bone resection with sacrifice of hearing (translabyrinthine), and finally maximum petrous drilling with sacrifice of hearing along with transposition of the facial nerve (transcochlear). Ninety-three percent of the cases returned to their premorbid occupations.     

Combined Approach for Lesions Involving the Cerebellopontine Angle and Skull Base: Experience with 30 Cases

This article presents a series of 30 patients who underwent a combination of the subtemporal and posterior fossa approaches for exposure of lesions in the clivus or medial petrous region. This combined supra- and infratentorial approach is divided into three variations with progressively greater petrous bone resection to increase exposure of the clivus and medial petrous region. The approach has been divided into petrous bone resection with preservation of hearing (retrolabyrinthine), greater petrous bone resection with sacrifice of hearing (translabyrinthine), and finally maximum petrous drilling with sacrifice of hearing along with transposition of the facial nerve (transcochlear). Ninety-three percent of the cases returned to their premorbid occupations.     

Large sphenoid wing meningiomas involving the cavernous sinus: conservative surgical strategies for better functional outcomes

OBJECTIVE: The ability to resect meningiomas that involve the medial and anterior compartments of the cavernous sinus has been refuted. In this retrospective study, we determined the efficacy of total resection of meningiomas that invade the cavernous sinus but are restricted to the lateral compartment. METHODS: We reviewed the charts of 38 consecutive patients with sphenocavernous, clinoidocavernous, and sphenoclinoidocavernous meningiomas who underwent surgical treatment. We assessed early and late cranial nerve morbidity, extent of resection, and long-term outcome (mean, 96 mo). RESULTS: In all patients, tumors exceeded 3 cm diameter. In 22 of 24 patients, total microscopic excision was achieved in tumors that involved only the lateral compartment of the cavernous sinus and touched or partially encased the cavernous internal carotid artery (i.e., modified Hirsch Grades 0 and 1, respectively). In 2 of 24 patients, remaining tumor infiltrated the superior orbital fissure. All 14 patients who had tumors that encased (with or without narrowing) the cavernous segment of the internal carotid artery (Hirsch Grades 2-4) underwent incomplete resection. Among 38 patients, mortality was 0%, late cranial nerve deficits remained in 6 (16%), and late Karnofsky Performance Scale scores exceeded 90 in 34 patients (90%). Four patients (10.5%) developed a recurrence or regrowth. Of 20 patients who were treated with either linear accelerator-based stereotactic radiosurgery or fractionated conformal radiotherapy, 11 had residual tumor and a moderate to high proliferative index, 4 had atypical tumors and 1 had angioblastic meningioma after total excision, 2 had regrowth, and 2 had recurrent tumors. In 18 (90%) of the 20 patients who underwent radiation, tumor size was reduced or controlled. CONCLUSION: On the basis of this study and a review of the literature, we demonstrate that sphenocavernous, clinoidocavernous, and sphenoclinoidocavernous meningiomas of Hirsch Grades 0 and 1 can be excised from the lateral compartment of the cavernous sinus without postoperative mortality and with acceptable rates of morbidity. Residual tumor in the medial compartment (Hirsch Grades 2-4) may be treated with some form of radiation therapy or observation.     

Management of bone-invasive en-plaque petrosal meningiomas. Removal using tailored petrosectomy

BACKGROUND AND PURPOSE: The invasion of bone responsible for hyperostosis is a typical phenomenon associated with en-plaque meningiomas. Although the sphenoid wing and spheno-orbital region are most frequently affected, petrosal involvement is rare and its surgical treatment difficult. Hyperostosis is caused by bone invasion, is responsible for the clinical signs, and prompts the surgeon to use an à la carte drilling that has to be evaluated preoperatively and carried out depending on tumor extension and the treatment goals. METHODS: We report two cases of invasive and evolving en-plaque petrosal meningiomas. Hyperostosis, bony modifications, and intracranial portion of the lesion were responsible for cophosis, facial palsy, trigeminal neuralgia, dysphonia, and laryngeal palsy in one case, and were responsible for hearing loss and facial palsy in the other case. RESULTS: In both cases, the à la carte petrosectomy allowed us to achieve total removal of the lesion. In one case, we used a trans- and infralabyrinthine transjugular approach (to control the extension of the lesion in the jugular foramen, within the sinusojugular axis, and in the internal auditory canal), associated with an anterior petrosectomy (to control the invaded petrous apex, Meckel's cave, and a middle cranial fossa extension). In the other case, we used a retro- and infralabyrinthine transsigmoid transtentorial approach to control the venous axis, the posterior fossa dura, and the tentorium. Total removal of the tumor including bone invasion was achieved in both cases. Neurological deficits improved or remain unchanged. Transient postoperative facial palsy recovered in two months. CONCLUSIONS: An à la carte petrosectomy performed by a surgical team with great expertise in the field of petrous bone anatomy and segmentation should lead to total removal including exposure of the dural tail and intracranial portion of the tumor, while preserving all cranial nerve functions.     

Presentation and patterns of late recurrence of olfactory groove meningiomas

The objective of this article is to present the recurrence pattern of olfactory groove meningiomas after surgical resection. Four patients, one female and three males, with surgically resected olfactory groove meningiomas presented with tumor recurrence. All patients underwent resection of an olfactory groove meningioma and later presented with recurrent tumors. The mean age at initial diagnosis was 47 years. All presented initially with vision changes, anosmia, memory dysfunction, and personality changes. Three patients had a preoperative MRI scan. All patients had a craniotomy, with gross total resection achieved in three, and 90% tumor removal achieved in the fourth. Involved dura was coagulated, but not resected, in all cases. Three patients were followed with routine head CT scans postoperatively, and none was followed with MRI scan. The mean time to recurrence was 6 years. Three patients presented with recurrent visual deterioration, and one presented with symptoms of nasal obstruction. Postoperative CT scans failed to document early tumor recurrence, whereas MRI documented tumor recurrence in all patients. Tumor resection and optic nerve decompression improved vision in two patients and stabilized vision in two. Complete resection was not possible because of extensive bony involvement around the anterior clinoid and inferior to the anterior cranial fossa in all cases. Evaluation of four patients with recurrent growth of olfactory groove meningiomas showed the epicenter of recurrence to be inferior to the anterior cranial fossa, with posterior extension involving the optic canals, leading to visual deterioration. This location led to a delay in diagnosis in patients who were followed only with routine CT scans. Initial surgical procedures should include removal of involved dura and bone, and follow-up evaluation should include formal ophthalmologic evaluations and routine head MRI scans.     

Surgical excision of clival tumors via the enlarged transcochlear approach. Indications and results.

BACKGROUND: The results of the surgical resection of 9 clival tumors using the enlarged transcochlear approach (ETCA) are evaluated. The literature is reviewed to compare the ETCA with other approaches to the clival and petroclival region; the surgical indications are discussed. METHODS: Between June 1996 and June 1997, 9 patients were operated on through the ETCA either alone or combined with other approaches. Only meningiomas and chordomas with a significant involvement of the clivus and huge extension into the posterior fossa were included into this study. RESULTS: Gross total tumor removal was achieved in 5 cases and in 4 cases a residual meningioma was left in place inside the cavernous sinus and treated by radiosurgery. No postoperative mortality or major neurological morbidity were recorded. The postoperative facial nerve function was good in 75% of cases. No tumor recurrence was recorded (mean follow-up = 45.9 months). CONCLUSIONS: The indications to the ETCA should be as strict as possible. The ETCA is an effective procedure in the treatment of large clivopetrous tumors. Tumor characteristics like consistency, vascularity, encasements of vertebro-basilar vessels, bone erosion and previous surgery are also indicative. The transient postoperative facial nerve palsy and deafness should be considered as major disadvantages related to this approach.     

Presentation and Patterns of Late Recurrence of Olfactory Groove Meningiomas

The objective of this article is to present the recurrence pattern of olfactory groove meningiomas after surgical resection. Four patients, one female and three males, with surgically resected olfactory groove meningiomas presented with tumor recurrence. All patients underwent resection of an olfactory groove meningioma and later presented with recurrent tumors. The mean age at initial diagnosis was 47 years. All presented initially with vision changes, anosmia, memory dysfunction, and personality changes. Three patients had a preoperative MRI scan. All patients had a craniotomy, with gross total resection achieved in three, and 90% tumor removal achieved in the fourth. Involved dura was coagulated, but not resected, in all cases. Three patients were followed with routine head CT scans postoperatively, and none was followed with MRI scan. The mean time to recurrence was 6 years. Three patients presented with recurrent visual deterioration, and one presented with symptoms of nasal obstruction. Postoperative CT scans failed to document early tumor recurrence, whereas MRI documented tumor recurrence in all patients. Tumor resection and optic nerve decompression improved vision in two patients and stabilized vision in two. Complete resection was not possible because of extensive bony involvement around the anterior clinoid and inferior to the anterior cranial fossa in all cases. Evaluation of four patients with recurrent growth of olfactory groove meningiomas showed the epicenter of recurrence to be inferior to the anterior cranial fossa, with posterior extension involving the optic canals, leading to visual deterioration. This location led to a delay in diagnosis in patients who were followed only with routine CT scans. Initial surgical procedures should include removal of involved dura and bone, and follow-up evaluation should include formal ophthalmologic evaluations and routine head MRI scans.