Posterior Cranial Fossa Meningiomas

This study evaluated the outcomes, complications, and recurrence rates of posterior cranial fossa meningiomas. We retrospectively reviewed our surgical experience with 64 posterior cranial fossa meningiomas. Mean age was 56 years with a female preponderance (67.2%). Headache was the most common symptom. Retrosigmoid approach was the commonest surgical procedure (23.4%). The incidence of cranial nerve related complications was 28%. Postoperatively facial nerve weakness was observed in 11%. The incidence of cerebrospinal fluid leak was 4.6%. Gross total resection was achieved in 37 patients (58%). Sixteen patients (25%) with residual tumors underwent Gamma knife radiosurgery. Recurrence or tumor progression was observed in 12 patients (18.7%). Operative mortality was 3.1%. At their last follow-up, 93% of the cases achieved Glasgow Outcome Scale scores 4 or 5. Total excision is the ideal goal which can be achieved with meningiomas located in certain location, such as lateral convexity, but for other posterior fossa meningiomas the close proximity of critical structures is a major obstacle in achieving this goal. In practicality, a balance between good functional outcome and extent of resection is important for posterior cranial fossa meningiomas in proximity to critical structures.     

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.     

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.     

Association between absence of epidermal growth factor receptor immunoreactivity and poor prognosis in patients with atypical meningioma

OBJECT: The clinical behavior of meningiomas is variable. Because multiple growth factor receptors have been identified in these tumors, the authors sought to assess the capacity of the expression patterns of a subset of these receptors to stratify meningioma cases. METHODS: Eighty-four meningiomas were analyzed, including 36 benign, 29 atypical, and 19 malignant lesions. Immunohistochemical staining was performed for epidermal growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR)-beta, basic fibroblast growth factor receptor (BFGFR), and MIB-1. Survival analyses were performed using follow-up data obtained in patients with newly diagnosed tumors. Immunoreactivity for EGFR was observed in 47% of benign, 48% of atypical, and 42% of malignant tumors. Staining for BFGFR was identified in 89% of benign, 97% of atypical, and 95% of malignant lesions. Immunostaining for PDGFR-beta was evident in all the lesions assessed. Mean MIB-I indices for benign, atypical, and malignant cases were 3.6 (range 0.5-15.3), 8.2 (range 1.5-23.1) and 18.3 (range 1.0-55.8), respectively. Overall mean follow-up duration was 9.0 years (range 5.1-18.8 years). Lack of EGFR immunoreactivity was identified as a strong predictor of shorter overall survival in patients with atypical meningioma (p = 0.003, log-rank test). This association was not evident in cases of benign or malignant meningiomas. CONCLUSIONS: There is a significant association between EGFR immunoreactivity and prolonged survival in patients with atypical meningioma. Given the variable behavior of atypical meningiomas, EGFR assessment could improve existing strategies for patient stratification and treatment.     

枕骨大孔区肿瘤的显微外科治疗

目的 探索枕骨大孔区肿瘤的治疗方法以提高治疗效果。方法 通过显微外科手术治疗31例枕骨大孔区肿瘤,其中脑膜瘤13例,神经鞘瘤15例,脊索3例。根据肿瘤附着点、生长方式及手术入路将肿瘤分为2种类型：I型：肿瘤主要位于枕骨大孔前方,包括基底起源于枕骨大孔上方、前方和前侧方,共15例;Ⅱ型：肿瘤主要位于枕骨大孔后方,包括基底起源于枕骨大孔后方、后侧方和椎管内,共16例。采用3种手术入路切除肿瘤：枕颈后正中和侧方入路18例,远外侧或经髁入路10例,枕下乙状窦后入路3例。结果 肿瘤全部切除25例,次全切除5例,部分切除1例,无手术死亡。I型枕骨大孔区肿瘤全切除9例,次全切除5例,部分切除1例;Ⅱ型均全切除。结论 I型枕骨大孔区肿瘤,手术全切除肿瘤困难,远外侧经髁入路是切除I型枕骨大孔区肿瘤最有效的方法;Ⅱ型肿瘤容易全切除,预后良好。     

Foramen magnum meningiomas: experiences in 114 patients at a single institute over 15 years

BackgroundAlthough there has been great development in the anatomical understanding and operative techniques for skull base tumors, controversy still exists regarding the optimal surgical strategies for the FMMs. We report clinical and radiologic features as well as the surgical findings and outcome for patients with FMM treated at our institution over the last 15 years.MethodsWe reviewed 114 consecutive cases of FMM operated between May 1993 and June 2008 in the neurosurgery department at Beijing Tiantan Hospital.ResultsThere were 68 female and 46 male patients (mean age, 52.3 years; range, 28-76 years). Foramen magnum meningiomas were classified as anterior (80 cases), anterolateral (24 cases), and posterolateral (10 cases). Mean duration of symptoms was 11.7 months (ranging from 1.5 to 240 months). Cervico-occipital pain (80.7%) and headache and dizziness (42.1%) were the most common presenting symptoms. The preoperative KPS was 72.5 ± 8.3. Mean maximum diameter of the tumors on MRI was 3.35 cm (range, 1.5-4.7 cm). Posterior midline approach was performed in 10 cases, far-lateral retrocondylar approach in 97 cases, and extended far-lateral approach in 7 cases. Gross total resection was achieved in 86.0% of patients and subtotal resection in 14.0%. Surgical mortality was 1.8%. Follow-up data were available for 93 patients, with a mean follow-up of 90.3 months (range, 1-180 months), of which 59 (63.4%) lived a normal life (KPS, 80-100).ConclusionOur experience suggests that most anterior and anterolateral FMMs can be completely resected by a far-lateral retrocondylar approach without resection of the occipital condyle. Complete resection of the tumor should be attempted at the first operation. Postoperative management of FMM is important for the prognosis.     

Posterior fossa arachnoid cysts and cerebellar tonsillar descent: short review

The objective of this study was to analyze the association of cerebellar tonsillar descent and syringomyelia in patients with posterior fossa arachnoid cysts. We reviewed the medical records of ten patients (mean, age 33; range, 24–49 years) diagnosed with posterior fossa arachnoid cyst and tonsillar descent. Symptoms evolved over a mean of 12 months (range, 6 months to 3 years). Syringomyelia was present in six cases. Six patients underwent a suboccipital craniectomy, three cases underwent an additional C1 laminectomy, and a further case had a limited craniectomy and tonsillar reduction. Three patients were also treated for hydrocephalus: one with a ventriculoperitoneal shunt and two with endoscopic third ventriculostomy. Two patients had conservative treatment. The posterior fossa arachnoid cysts were located at the vermis-cisterna magna (n = 4), the cerebellar hemispheres (n = 2), the cerebellopontine angle (n = 3), and the quadrigeminal cistern (n = 1). A patient with achondroplasia showed features of platybasia. Associated malformations included craniofacial dysmorphism in a patient diagnosed of trichorhinophalangeal syndrome and a case with a primary temporal arachnoid cyst. After a mean follow-up of 2 years (range, 3 months to 5 years), four patients showed resolution of their neurological symptoms, and two exhibited persisting ocular findings. Headaches and nuchalgia improved in four cases and persisted in four. Syringomyelia was resolved in four patients and improved in two. Patients harboring a posterior fossa arachnoid cyst may evolve with acquired Chiari malformation and syringomyelia. Initial management should be directed to decompressing the foramen magnum and should include the resection of the arachnoid cyst’s walls. A wait-and-see attitude can be implemented in selected cases. In our experience, hydrocephalus should be properly addressed before treating the arachnoid cyst.     

Outcome in 53 patients with spinal cord cavernomas

BACKGROUND: Prevalence of cerebral cavernomas in the general population is close to 0.5%. In contrast, SCCs are rare. The aim of this study was to determine the outcome of SCC in a large sample of patients. METHODS: Clinical and neuroradiologic findings were retrospectively collected in a multicentric study. Diagnosis was based on pathologic criteria or MR findings. RESULTS: Fifty-three patients were included (26 males, 27 females). Mean age at onset of symptoms was 40.2 years (11-80 years). Initial symptoms were progressive (32) or acute myelopathy (20). One case was asymptomatic. Triggering factors were found in 14 of the patients (26%). Clinical symptoms were related to spinal cord compression (27) and hemorrhage (22). Spinal cord cavernoma was thoracic in 41 cases and cervical in 12. Mean size of the lesions was 16.3 mm (3-54 mm). In the 40 surgical patients, long-term follow-up was available in 37 cases for a mean time of 7.3 years (0.4-50 years). During the follow-up period, 20 patients improved, 6 remained on their preoperative baseline, and 11 got worse. Surgical improvement was more often found in posterior rather than anterior location. Using McCormick classification, 22 patients were autonomous (grades 1-2), 12 handicapped (grade 3), and 3 bedridden (grade 4) at the end of the follow-up. CONCLUSIONS: This study has defined clinical and MR patterns of spinal cavernomas. Surgery lastingly improved more than half of the patients.     

Stereotactic radiosurgery for anterior foramen magnum meningiomas

BACKGROUND: Total microsurgical resection is the procedure of choice for growing and symptomatic foramen magnum meningiomas. We hypothesized that for patients with advanced age, complicating medical conditions, or residual or recurrent meningiomas at the foramen magnum, stereotactic radiosurgery would be a useful adjunctive (n = 2) or alternative (n = 3) treatment. METHODS: We report our experience in five elderly patients (73-84 years) who underwent gamma knife radiosurgery. The median tumor volume was 10.5 ml and the tumor margin dose varied from 10 to 16 Gy. Because of the irregular tumor volumes along the inferior clivus, multiple isocenters of irradiation were required (range, 2-8; mean 4.4). RESULTS: During the follow-up interval of 1-5 years (median, 3 years), one patient died of an intercurrent illness, and all remaining patients were stable without any further deterioration in their clinical condition. Follow-up imaging studies revealed a reduction in tumor volume in one patient and no further growth in the remaining four. CONCLUSION: We believe that stereotactic radiosurgery provides safe and effective management for patients who are poor candidates for resection of their foramen magnum meningiomas.     

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.     

Presentation and management of pediatric Chiari malformations without myelodysplasia

Chiari malformations without myelodysplasia are rarely diagnosed in the pediatric age group. With current neurodiagnostic techniques, however, they are being seen more frequently. Unfortunately, the prognosis is not clear because publications have included a number of different entities, used a variety of surgical approaches, and lacked long term follow-up. Sixteen patients younger than 20 years were treated for Chiari malformations (without myelodysplasia) between 1975 and 1985. The average age was 11 years, and the average duration of symptoms was 20 months. The common symptoms were isolated motor weakness (56%), pain (37.5%), and sensory loss (25%). Frequently seen signs were motor deficit (81%), sensory loss (50%), scoliosis (50%), and cranial nerve palsy (50%). The surgical procedures used were foramen magnum decompression (3 transoral clivus odontoid resections and 15 posterior fossa decompressions with dural grafting), alteration of cerebrospinal fluid (CSF) pathways at the cervicomedullary junction (plugging the foramen cecum and a 4th ventricle to subarachnoid shunt with posterior fossa decompression), and ventriculoperitoneal shunting (2 cases). In follow-up, 37.5% of the patients are asymptomatic, 50% are improved, and 12.5% are stable after an average follow-up period of 43 months. The asymptomatic group was younger (9.3 years) and had a shorter symptom duration (7.2 months) than both the improved (11.9 years, 16.4 months) and the stable groups (15 years, 20 months). Optimal outcome depends on complete evaluation of the abnormal CSF pathways and bony abnormalities at the craniovertebral junction. Operation is then directed toward correction of these abnormalities as delineated radiographically. Of our patients, 87.5% have at least shown improvement, which has been long term in all cases.     

Surgical management of bronchiectasis in childhood.

OBJECTIVE: Though there is a gradual decrease in the prevalence of bronchiectasis, it is still a cause of mortality and morbidity among children in developing countries such as Turkey. We reviewed the morbidity and mortality rates and the outcome of surgical treatment for childhood bronchiectasis. PATIENTS AND METHODS: Age, sex, etiological factors, symptoms, radiological examinations, surgical procedures, postoperative morbidity and mortality in patients aged 16 years and younger, operated for bronchiectasis between January 1991 and April 2006 in the Thoracic Surgery Clinic of Atatürk Training and Research Hospital for Chest Disease and Chest Surgery were reviewed retrospectively. RESULTS: Between January 1991 and April 2006, 176 cases aged 16 and younger were operated for bronchiectasis. There were 95 females (54%) and 81 males (46%), with a mean age of 12.3 years (range: 3.4-16 years). The most common cause of bronchiectasis was lung infection (n: 87, 49.4%). Main symptoms were coughing (n: 167, 94.9%), sputum (n: 139, 79%), hemoptysis (n: 78, 44.3%), and fever (n: 77, 43.7%). Mean duration of the symptoms in patients who were operated was 3.8 years (range: 0-7.6 years). Cases underwent a total of 201 operations: 19 cases had bilateral surgical resection and 6 cases had completion pneumonectomy. Majority of cases had complete resection (n: 165, 93.75%) while only 11 cases (6.25%) had incomplete resection. Mean duration of hospitalization was 8.9 days (range: 5-39 days). The outcome, based on the responses of patients postoperatively, was 'perfect' in 129 cases (73.3%), 'improved' in 41 cases (23.3%), and 'no changes' in 6 cases (3.4%). The mean follow-up after surgery was 4.3 years (range: 14 months to 7.2 years), mortality was 0% and morbidity was 13% (n: 23). CONCLUSION: With acceptable mortality and morbidity rates and high chance of cure after complete resection, surgical treatment is a successful and reliable method of treatment in childhood bronchiectasis that yields marked improvement in the quality of life.     

Bulbar urethral stricture repair with buccal mucosa graft urethroplasty

OBJECTIVES: Evaluation of the use of buccal mucosa graft as single-stage urethral reconstruction in an adult population with a stenosis of the bulbar urethra. METHODS: In our Department between April 1996 and February 1999, 20 patients with bulbar urethra stenosis underwent single-stage urethroplasty using a buccal mucosa graft. Mean age of patients was 52 years (range 14-70). The etiology of urethral stricture was inflammation (4 cases), iatrogenic (5 cases) and idiopathic (11 cases). A ventral onlay patch (mean length 3.6 cm, range 2.5-5) was employed in all cases. RESULTS: During the follow-up (median 13 months, range 6-28) the overall success rate was 80%. The success rate was 75% for inflammatory strictures, 80% for iatrogenic strictures and 81% for strictures of unknown etiology. CONCLUSIONS: Although longer follow-up is needed, free graft urethroplasty with buccal mucosa graft represents a simple surgical option which has produced encouraging results. This is probably due to the quality of the tissue employed which at present seems to represent the first-choice solution in selected cases.     

Posterior approach to ventrally located spinal meningiomas

For the resection of anteriorly located meningiomas, various approaches have been used. Posterior approach is less invasive and demanding; however, it has been associated with increased risk of spinal cord injury. We evaluated ten consecutive patients that underwent surgery for spinal meningiomas. All patients were preoperative assessed by neurological examination, computed tomography and magnetic resonance imaging. All tumors were ventrally located and removed via a posterior approach. Transcranial motor-evoked potentials (TcMEPs), somatosensory-evoked potential (SSEP) and free running electromyography (EMG) were monitored intraoperative. Postoperative all patients had regular follow-up examinations. There were four males and six females. The mean age was 68.2 years (range 39–82 years). In nine out of ten cases, the tumor was located in the thoracic spine. A case of a lumbar meningioma was recorded. The most common presenting symptom was motor and sensory deficits and unsteady gait, whereas no patient presented with paraplegia. All meningiomas were operated using a microsurgical technique via a posterior approach. During the operation, free running EMG monitoring prompted a surgical alert in case of irritation, whereas TcMEP and SSEP amplitudes remained unchanged. Histopathology revealed the presence of typical (World Health Organisation grade I) meningiomas. The mean Ki-67/MIB-1 index was 2.75% (range 0.5–7). None of our patients sustained a transient or permanent motor deficit. After a mean follow-up period of 26 months (range 56–16 months), no tumor recurrence and no instability were found. Posterior approach for anteriorly located meningiomas is a safe procedure with the use of intraoperative monitoring, less invasive and well-tolerated especially in older patients. Complete tumor excision can be performed with satisfactory results.     

Laparoscopic repair of ventral and incisional hernias: our experience in 150 patients

BACKGROUND: Incisional hernias develop in 2 to 20% of laparotomy incisions. Approximately 100,000 ventral hernias are operated on each year in the United States. The reported recurrence rates for open repair are 25-52% for primary and 12.5-19% for mesh repair. Compared to the open technique, laparoscopic repair has low rates of complications and recurrence, greater patient acceptance, and shorter hospital stay. MATERIALS AND METHODS: Between April 1999 and April 2004, we treated 150 patients (111 female, 39 male) with ventral and incisional hernias laparoscopically. Data concerning the age and sex of patients, the location, number, and size of fascial defects, the type of hernias and their contents, the size and type of meshes used in repair, operative time, length of hospital stay, and postoperative complications were collected. RESULTS: Of the 150 patients, 92 had incisional hernias and 58 had umbilical hernias. Polypropylene was used in 85 cases, dual mesh in 40 cases, and composite mesh in 25 cases. The mean age of the patients was 56.0 years (range, 33-81 years). Mean operative time was 63 minutes (range, 30-125 minutes). Mean postoperative hospital stay was 2.5 days (range, 1-15 days). The postoperative complication rate was 8.6% (seroma, paralytic ileus, small bowel injury, and suture-site neuralgia). The mean follow-up period was 32 months (range, 4-60 months). There was a 3% recurrence rate. Three subileus cases were detected during follow-up. CONCLUSION: The laparoscopic approach to ventral and incisional hernias is safe, feasible, and a good alternative to the open approach. Our results are comparable with those of other reports in the literature.     

Multimodality treatment of posterior fossa arteriovenous malformations

OBJECT: Posterior fossa arteriovenous malformations (AVMs) are relatively uncommon and often difficult to treat. The authors present their experience with multimodality treatment of 76 posterior fossa AVMs, with an emphasis on Spetzler-Martin Grades III-V AVMs. METHODS: Seventy-six patients with posterior fossa AVMs treated with radiosurgery, surgery, and endovascular techniques were analyzed. RESULTS: Between 1982 and 2006, 36 patients with cerebellar AVMs, 33 with brainstem AVMs, and 7 with combined cerebellar-brainstem AVMs were treated. Natural history data were calculated for all 76 patients. The risk of hemorrhage from presentation until initial treatment was 8.4% per year, and it was 9.6% per year after treatment and before obliteration. Forty-eight patients had Grades III-V AVMs with a mean follow-up of 4.8 years (range 0.1-18.4 years, median 3.1 years). Fifty-two percent of patients with Grades III-V AVMs had complete obliteration at the last follow-up visit. Three (21.4%) of 14 patients were cured with a single radiosurgery treatment, and 4 (28.6%) of 14 with 1 or 2 radiosurgery treatments. Twenty-one (61.8%) of 34 patients were cured with multimodality treatment. The mean Glasgow Outcome Scale (GOS) score after treatment was 3.8. Multivariate analysis performed in the 48 patients with Grades III-V AVMs showed radiosurgery alone to be a negative predictor of cure (p = 0.0047). Radiosurgery treatment alone was not a positive predictor of excellent clinical outcome (GOS Score 5; p > 0.05). Nine (18.8%) of 48 patients had major neurological complications related to treatment. CONCLUSIONS: Single-treatment radiosurgery has a low cure rate for posterior fossa Spetzler-Martin Grades III-V AVMs. Multimodality therapy nearly tripled this cure rate, with an acceptable risk of complications and excellent or good clinical outcomes in 81% of patients. Radiosurgery alone should be used for intrinsic brainstem AVMs, and multimodality treatment should be considered for all other posterior fossa AVMs.     

Results in the operative treatment of elderly patients with intracranial meningioma

With life expectancy in the industrial nations increasing during recent years, the number of patients older than 70 years with intracranial tumours and, especially, meningiomas is rising. To evaluate the indications for operative treatment, we reviewed 66 patients older than 70 years who were operated upon for intracranial meningioma in our department between 1991 and 1997. The mean age was 75 years. The oldest patients were 86 years old. Thirteen patients with recurrent meningiomas were operated upon. The mortality rate was 7.6%. Neurological symptoms improved in 38 patients (57.6%), were unchanged in 11 (16.6%), and deteriorated in 12 (18.2%). Patients with recurrent meningiomas seem to have a higher operative risk and their outcome is worse than after a primary operation. In general, there were good postoperative results in patients with few concomitant diseases, small meningiomas, small edema, short time of operation, and accessible location (convexity rather than skull base). Age in general is not a contraindication for operation. In cases of incidental findings of small meningiomas, we recommend observation and MRI follow-up. Symptomatic meningiomas should be removed whenever there is an acceptable risk from an internal or anaesthesiological point of view. Received: 23 February 1999 / Accepted: 15 April 1999     

Recurrence of olfactory groove meningiomas

OBJECTIVE: Despite apparent gross total resection, olfactory groove meningiomas have a high rate of late recurrence (average, 23%). In this retrospective study, we confirmed that the sites of these recurrences are the cranial base and paranasal sinuses. We postulated that these recurrences stem from conservative handling of the underlying invaded bone. Therefore, we analyzed patient outcomes according to the radicality of surgical resection. METHODS: Fifteen consecutive patients with a diagnosis of olfactory groove meningioma were treated surgically between 1992 and 2001 (nine new cases, six recurrent). Only patients with benign meningiomas were included; atypical and malignant meningiomas were excluded. Surgical resection included the dura and drilling of the underlying bone and resection of involved mucosa. We reviewed each patient's clinical records, radiological studies, sites of recurrence, grade of previous resection, and complications. RESULTS: Olfactory groove meningiomas invaded the underlying bone in 13 cases. All patients with recurrence had previously undergone a surgical resection corresponding only to Simpson Grade 2, which does not include the removal of underlying invaded bone. The sites of recurrence were in the cranial base or adjacent paranasal sinuses. The time to recurrence varied from 1 to 12 years (average, 7 yr; mean, 8 yr). Three patients had undergone one previous resection, two had undergone two previous resections, and one had undergone four previous operations. The ethmoid sinus was involved in all cases of recurrence, either with the sphenoid sinus or with an intracranial recurrence. Thirteen patients underwent complete resection of underlying bone and the invaded paranasal sinuses, then reconstruction of the anterior fossa. No patient died. There were three instances of cerebrospinal fluid leakage (one requiring operative repair), one case of delayed worsening vision after initial improvement, and two cases of transient cranial nerve palsy (Cranial Nerves III and IV). There was no recurrence at follow-up (average, 3.7 yr; range, 1-7.3 yr). CONCLUSION: The cranial base and paranasal sinuses are sites of predilection for recurrence of olfactory groove meningiomas. Recurrence is the result of a direct extension attributable to incomplete resection of involved bone and regrowth at the edge of a previous surgical field. Extensive resection of all suspicious underlying bone is a complement to radical removal of these lesions. Reconstruction with a vascularized pericranial flap to prevent cerebrospinal fluid leakage is crucial.     

Boost radiosurgery for treatment of brain metastases after surgical resections

BACKGROUND: We evaluated results of resection surgery followed by boost radiosurgery for the treatment of brain metastases. METHODS: We treated 21 patients (13 male, 8 female) with surgical resection (subtotal or total) followed by boost radiosurgery. The mean patient age was 61 years (range, 41-80 years); supratentorial lesions were treated in 12 patients, and posterior fossa lesions were treated in 9 patients. The most common primary cancers were lung (24%) and colon (24%). Fifty-three percent of patients had brain metastases only, whereas 47% had extracranial metastases. The radiosurgery dose plan was designed to radiate the operative cavity; the mean treatment volume (50% isodose) was 10.7 mL (range, 3.4-23.3 mL), and the mean marginal dose was 17 Gy (range, 13-20 Gy). RESULTS: Local control was achieved in 16 (76%) patients. However, new intracranial lesions developed in 10 patients, and meningeal carcinomatosis occurred in 5 patients. Local tumor recurrence occurred more often for patients treated with lower radiotherapy doses (<18 vs > or =18 Gy, P = .03), and meningeal carcinomatosis occurred more often in patients with posterior fossa lesions (P = 0.05). Gamma knife radiosurgery was performed in 13 patients, and whole-brain radiation was performed in 2 patients. No patients experienced symptomatic radiation injury, and the median survival time was 20 months. CONCLUSIONS: Although boost radiosurgery is less invasive and reduces morbidity, the radiosurgical dose must be higher than 18 Gy for the treatment to be most effective. Treatment of lesions of the posterior fossa must be considered carefully because of the higher frequency of meningeal carcinomatosis. Also, we recommend that the surgeons who operate on the metastatic tumors must try to decrease the resected cavity volume and to prevent cerebrospinal fluid dissemination at the operation for posterior fossa lesions.