Posterior Fossa Meningioma Research Articles

Embolization of posterior fossa meningiomas supplied with meningohypophyseal trunk by using n-BCA and dual balloon protection.

Efficacy of tumor embolization for posterior fossa meningioma is controversial due to the lack of adequate embolization for dangerous feeders. Of these, a meningohypophyseal trunk (MHT) has high therapeutic value despite the high risks associated with embolization. To analyze the utility of preoperative MHT embolization for posterior fossa meningiomas using n-BCA with dual balloon protection, a single center retrospective record review was performed on eight consecutive patients who underwent preoperative tumor embolization via the MHT for posterior fossa meningiomas between 2020 and 2024. All patients successfully embolized the MHT using n-BCA. Complete obliteration was achieved in five cases, which is related to the tentorial artery alone as the feeding vessel. None of the patients had cerebral infarction associated with distal embolization. One patient experienced worsening of preoperatively observed abducens nerve palsy due to cranial nerve ischemia. Gross total resection was achieved in seven of eight cases. The mean estimated blood loss during surgical resection was 186 mL (range, 39-392 mL). The mean operative time was 431 min (range, 317-767 min). The MHT embolization of posterior fossa meningiomas by using n-BCA is technically feasible with a high success rate and an acceptable complication rate. MHT=meningohypophyseal trunk; ILT=inferolateral trunk; CPA=Cerebellopontine angle; BGC=balloon guide catheter; PVA=polyvinyl alcohol; GTR=Gross Total Resection; CN=Cranial nerve.

Peculiarities of cerebral blood flow and vascular reactivity in patients with large and giant tumors of the cerebello-pontine angle

Background. Vestibular schwannomas and posterior fossa meningiomas are one of the most difficult tumors for surgical treatment. The mortality rate after their removal reaches 13,5 %. The main causes of death are hemorrhagic and ischemic complications. There are no studies in the literature on tissue perfusion of brainstem structures and cerebellum and reactivity of vertebral and basilar arteries in patients with extraaxial tumors of the posterior cranial fossa. Therefore, the study of the blood supply of the brainstem structures and cerebellum, as well as the functional characteristics of the vertebral and basilar arteries in these patients is of considerable interest.Aim. To evaluate tissue perfusion of the pons and cerebellum, as well asthe reactivity of the vertebral and basilar arteries in patients with large and giant vestibular schwannomas and posterior fossa meningiomas.Materials and methods. Eighty-two patients with large and giant extraaxial tumors of the base of the posterior cranial fossa were examined. The median age was 54 [44; 61] years. Vestibular schwannomas were diagnosed in 52.4 % of patients, and meningiomas of the posterior cranial fossa were diagnosed in 47.6 %. All patients underwent duplex scanning of the basilar and vertebral arteries. We evaluated linear blood flow and coefficients of reactivity and index of vasomotor reactivity. We investigated the metabolic reactivity of cerebral blood flow by conducting hyper- and hypocapnic tests. Computed tomography perfusion imaging was performed in 18 patients. We detected cerebral blood volume, cerebral blood flow, mean transit time of contrast agent and time to peak of contrast agent. Measurements were carried out in six regions of interest located symmetrically on the pons and in the white matter of the cerebellar hemispheres on the side of the tumor and on the opposite side.Results. Linear blood flow rates in the intracranial segments of the vertebral and the basilar arteries in patients with tumors were higher than in the comparison group (p<0.05). These patients are characterized by a decrease of reactivity coefficients in the vertebral and basilar arteries, especially when performing hypercapnic tests (p <0.05). Paradoxical reactivity and areactivity were diagnosed in 34.9 % of patients with vestibularschwannomas and 25.6 % with meningiomas. In the pons on the side of the tumor in patients with vestibularschwannomas, a decrease in cerebral blood flow by 19.3 %, an increase in cerebral blood volume by 33.3 % and an increase in mean transit time of contrast agent and in time to peak of contrast agent by 48.1 % and 71.1 % (p <0.05) were found. In patients with meningiomas in the pons on the side of the tumor, all perfusion parameters were higher (p<0.05). In the deep regions of the cerebellar hemisphere on the side of the tumor in patients with tumors, all perfusion parameters were higher compared to the opposite side.Conclusion. The results of the study made it possible to quantify cerebral blood flow in patients with large and giant vestibular schwannomas and meningiomas of the posterior cranial fossa base. The revealed changes indicate the risk of developing pathological vascular reactions and disorders of cerebral blood flow in the postoperative period.

Endoscope-Assisted Microsurgery for Posterior Fossa Skull Base Meningioma Surgery: Technique and Results.

Surgery of posterior fossa meningiomas is extremely challenging even for experienced skull base surgeons because of the close proximity to cranial nerves and tight spaces. Endoscope-assisted surgery for posterior fossa meningiomas can enable a high degree of tumor resection even when using small approaches. This study describes the advantage of endoscope-assisted microneurosurgery in resection of posterior fossa skull base meningiomas and the clinical outcome. All endoscope-assisted surgeries for resection of posterior fossa meningiomas performed between 2002 and 2016 in our department were retrospectively analyzed. For data acquisition, the patient files were used. Tumor size and extent of resection were evaluated on pre- and postoperative magnetic resonance imaging. The value of endoscope assistance was assessed according to the intraoperative videos and the surgical notes. Complications and long-term outcomes were evaluated. We identified 39 female and 10 male patients. The mean age of the patients at the time of surgery was 55 years, ranging from 25 to 78 years. The mean follow-up was 93.8 months. A total of 41% of the tumors were large to giant. The retrosigmoid approach was used in most patients (45). A gross total resection could be achieved in 38 patients (78%). In 11 patients (22%), a near total resection was performed. In 27 patients (55%), a hidden residual tumor, which could not been visualized with the operating microscope, was identified with the endoscope. In 6 patients (22.2%), the internal auditory canal was visualized, in 9 patients (33.3%), the Meckel's cave was visualized, and in 5 patients (18.5%), both were visualized under endoscope assistance. In 26 of those patients (96.3%), the residual tumor was resected under endoscopic view. Endoscope-assisted surgery for posterior fossa skull base meningiomas enables a high degree of tumor resection, avoids more invasive skull base approaches, and reduces the amount of cerebellar retraction.

Incidence and Clinical Presentation of Pre- and Postoperative Seizures in Patients With Posterior Fossa Meningiomas.

Seizures are a common symptom of supratentorial meningiomas with pre- and postoperative seizure rates of approximately 30% and 12%, respectively, especially in parasagittal and convexity meningiomas. Less is known about the association between seizures and posterior fossa meningiomas. This study evaluates the prevalence, potential causes, and outcomes of seizures in patients who have undergone surgery for posterior fossa meningioma. This is a retrospective, observational, single-center studyof consecutive patients who underwent surgical resection of posterior fossa meningiomas between 2009 and 2017. We retrospectively identified patients with seizures and analyzed patient demographics, tumor characteristics, and procedural characteristics. A total of 44 patients (mean age: 59.8 ± 13.5 years) were included. Twenty-six tumors were located at the cerebellar convexity and tentorium (59.1%), 12 at the cerebellopontine angle (27.3%), four at the clivus (9.1%), and two at the foramen magnum (4.5%). Seizures were the presenting symptom of cerebellar meningioma in two patients. Patients were seizure-free after surgery. Three patients had their first seizure after surgery (interval between surgery and first seizure: two days to 17 months). Analysis of these three patients revealed possible causes of postoperative seizures: radiation necrosis and edema, hyponatremia, and preoperative hydrocephalus. In all patients with postoperative seizures, long-term seizure control was achieved with the administration of antiepileptic drugs. The incidence of seizures in patients with posterior fossa meningiomas is relatively low. Antiepileptic drugs can help to achieve seizure control.

Posterior cranial fossa meningiomas: Comparison of results between patients older and younger than 70 years

IntroductionSurgical strategy for meningioma resection in the elderly is controversial: diverse studies in the literature have pointed at the age as a negative prognostic factor in terms of postoperative results. Research questionThe aim of this study is to compare surgical outcomes after resection of posterior fossa meningiomas in <70 and ≥ 70 years-old age groups. Material and methodsWe reviewed 72 patients affected by posterior fossa meningiomas who underwent surgical treatment at San Filippo Neri Hospital, Rome, Italy between September 2010 and December 2022. We analyzed data regarding tumor size, clinical presentation, extent of resection and complication/mortality. ResultsThe groups consisted of 52 (72,2%) young and 20 (27,8%) elderly patients. Gross total resection rate was significantly higher among youngsters (p = 0,013), mainly for planned subtotal removal in older patients. At 3-month follow-up, clinical improvement was seen in 19 (36,5%) young and 7 (35,0%) elderly patients, which raised at last follow-up, being 84,6% (44) and 80,0% (16), respectively (p = 0,406). Two cases of progression/recurrence among the elderly and 1 among youngsters were observed; one case of mortality among the elderly was reported. Discussion and conclusionsSafety data regarding postoperative complications and mortality in our series seem to confirm that there is no significant difference between older and younger patients, as long as older patients are carefully selected. Therefore, if surgery is proposed, it should be radical if gross total resection could be safely attempted.

Lightfield hyperspectral imaging in neuro-oncology surgery: an IDEAL 0 and 1 study.

Hyperspectral imaging (HSI) has shown promise in the field of intra-operative imaging and tissue differentiation as it carries the capability to provide real-time information invisible to the naked eye whilst remaining label free. Previous iterations of intra-operative HSI systems have shown limitations, either due to carrying a large footprint limiting ease of use within the confines of a neurosurgical theater environment, having a slow image acquisition time, or by compromising spatial/spectral resolution in favor of improvements to the surgical workflow. Lightfield hyperspectral imaging is a novel technique that has the potential to facilitate video rate image acquisition whilst maintaining a high spectral resolution. Our pre-clinical and first-in-human studies (IDEAL 0 and 1, respectively) demonstrate the necessary steps leading to the first in-vivo use of a real-time lightfield hyperspectral system in neuro-oncology surgery. A lightfield hyperspectral camera (Cubert Ultris ×50) was integrated in a bespoke imaging system setup so that it could be safely adopted into the open neurosurgical workflow whilst maintaining sterility. Our system allowed the surgeon to capture in-vivo hyperspectral data (155 bands, 350-1,000 nm) at 1.5 Hz. Following successful implementation in a pre-clinical setup (IDEAL 0), our system was evaluated during brain tumor surgery in a single patient to remove a posterior fossa meningioma (IDEAL 1). Feedback from the theater team was analyzed and incorporated in a follow-up design aimed at implementing an IDEAL 2a study. Focusing on our IDEAL 1 study results, hyperspectral information was acquired from the cerebellum and associated meningioma with minimal disruption to the neurosurgical workflow. To the best of our knowledge, this is the first demonstration of HSI acquisition with 100+ spectral bands at a frame rate over 1Hz in surgery. This work demonstrated that a lightfield hyperspectral imaging system not only meets the design criteria and specifications outlined in an IDEAL-0 (pre-clinical) study, but also that it can translate into clinical practice as illustrated by a successful first in human study (IDEAL 1). This opens doors for further development and optimisation, given the increasing evidence that hyperspectral imaging can provide live, wide-field, and label-free intra-operative imaging and tissue differentiation.

Differences in Hearing, Balance, and Quality-of-Life Outcomes in Petroclival Versus Nonpetroclival Posterior Fossa Meningiomas.

To compare hearing, tinnitus, balance, and quality-of-life treatment outcomes of petroclival meningioma and nonpetroclival cerebellopontine angle meningioma cohorts. A retrospective cohort study of 60 patients with posterior fossa meningiomas, 25 petroclival and 35 nonpetroclival, who were treated at a single tertiary care center between 2000 and 2020. A survey battery that included the Hearing Effort of the Tumor Ear, Speech and Spatial Qualities of Hearing, Tinnitus Functional Index, Dizziness Handicap Inventory (DHI), and Short Form Health Survey. Petroclival and nonpetroclival cohorts were matched for tumor size and demographic features. Differences between groups in hearing, balance outcomes, and quality of life and patient factors that influence posttreatment quality of life. Petroclival meningioma patients reported poorer audiovestibular outcomes with a higher rate of deafness in the tumor ear (36.0% versus 8.6%, p = 0.032) and lower functional hearing by the Hearing Effort of the Tumor Ear, Speech and Spatial Qualities of Hearing (76.6 [6.1] versus 82.0 [4.4], p < 0.001). Current dizziness rate was higher (48.0% versus 23.5%, p = 0.05), with more severe dizziness by DHI (18.4 [4.8] versus 5.7 [2.2], p < 0.001). Both cohorts had similar high quality of life and low tinnitus severity indices. Quality-of-life Short Form Health Survey predictors were tumor size (p = 0.012) and DHI (p = 0.005) in multivariable analysis. Hearing and dizziness treatment outcomes of petroclival meningioma are poorer relative to other posterior fossa meningiomas. Despite audiovestibular outcome distinctions, the overall posttreatment quality of life was high for both petroclival and nonpetroclival meningioma.

Safeness and efficacy of 2-µm handheld thulium laser during microsurgical resection of supratentorial and infratentorial meningiomas: Experience of a single center.

We performed a retrospective nonrandomized study to analyze the results of a microsurgery of intracranial meningiomas using 2-μm thulium flexible handheld laser fiber (Revolix jr). From February 2014 to December 2021, 75 nonconsecutive patients suffering from intracranial meningiomas, admitted in our department, have been operated on with microsurgical technique assisted by 2-μm thulium flexible handheld laser. We have reviewed demographic and clinical data to evaluate safety and efficacy of the technique. There were no complications related to the use of the 2-μm thulium laser. We operated on a high percentage of cranial base and tentorial and posterior fossa meningioma in our series. The neurological outcome and degree of resection did not differ from previous series. The neurosurgical team found the laser easy to use and practical for avoiding bleeding and traction. The use of 2-μm thulium fiber handheld flexible laser in microsurgery of intracranial meningiomas seems to be safe and to facilitate tumor resection, especially in "difficult" conditions (e.g., deep seated, highly vascularized, and hard tumors). Even if in this limited retrospective trial the good functional outcome following conventional microsurgery had not further improved, nor the surgical time was reduced by laser, focusing its use on "difficult" (large and vascularized) cases may lead to different results in the future.

Left far-lateral approach for resection of a large foramen magnum meningioma encasing the dominant vertebral artery: 2-Dimensional operative video

Tumors at the craniocervical junction represent a formidable challenge due to its intimate association with the medulla and cervical spinal cord, lower cranial nerves, and vertebral artery (VA). Foramen magnum meningioma (FMM) reparents 2% of all intracranial meningiomas and 4% of posterior fossa meningiomas. The far lateral approach is preferred for FMM with VA involvement. Here, we describe a case of a 58-year-old woman who presented with headache, nausea and vomiting and gait disturbance and was found to have large FMM encasing the dominant VA. The patient was treated with a left far lateral approach with limited condylectomy resulting in gross total resection and preservation of lower cranial nerves function.

Treated large posterior fossa vestibular schwannoma and meningioma: Hearing outcome and willingness-to-accept brain implant for unilateral deafness.

To compare functional hearing and tinnitus outcomes in treated large (~ 3 cm) vestibular schwannoma (VS) and posterior fossa meningioma cohorts, and construct willingness-to-accept profiles for an experimental brain implant to treat unilateral hearing loss. A two-way MANOVA model with two independent variables (tumor type; time from treatment) and three dependent variables (hearing effort of tumor ear; abbreviated Speech, Spatial, and Qualities of Hearing scale (SSQ12); Tinnitus Functional Index (TFI)) was used to analyze data from VS (N=32) and meningioma (N=50) patients who were treated at a tertiary care center between 2010 and 2020. A query to probe acceptance of experimental treatment for hearing loss relative to expected benefit was used to construct willingness-to-accept profiles. Tumor type was statistically significant on the combined dependent variables analysis (F[3, 76]=19.172, p < .0005, Wilks' Λ=0.569). Meningioma showed better outcome for hearing effort (F[1, 76]=14.632, p < .0005) and SSQ12 (F[1, 76]=16.164, p < .0005), but not for TFI (F[1, 76]=1.247, p=.268) on univariate two-way ANOVA analyses. Superior hearing effort and SSQ12 indices in the short-term (< 2 years) persisted in the long-term (> 2 years) (p ≤ .017). At the 60% speech understanding level, 77% of respondents would accept an experimental brain implant. Hearing outcome is better for posterior fossa meningioma compared to VS. Most patients with hearing loss in the tumor ear would consider a brain implant if the benefit level would be comparable to a cochlear implant. 2.

Tumor control and radiobiological fingerprint after Gamma Knife radiosurgery for posterior fossa meningiomas: A series of 46 consecutive cases

IntroductionGamma Knife radiosurgery (GKR) can be a valuable treatment option for posterior cranial fossa meningiomas (PCFM). We retrospectively analyzed outcomes of GKR for PCFM. MethodsWere included forty-six patients with 47 PCFM. Primary endpoint was tumor control. Secondary endpoint was clinical improvement. Biologically effective dose (BED) was evaluated in relationship to primary and secondary outcomes. Mean marginal dose was 12.4 Gy (median 12, 12–14). Mean BED was 63.6 Gy (median 65, 49.1–88.3). Mean target volume (TV) was 2.21 cc (range 0.3–8.9 cc). ResultsOverall tumor control rate was 93.6% (44/47) after mean follow-up of 47.8 months ± 28.46 months (median 45.5, range 6–108). Radiological progression-free survival at 5 years was 94%. Higher pretherapeutic TVs were predictive for higher likelihood of tumor progression (Odds ratio, OR 1.448, 95% confidence interval - CI 1.001–2.093, p = 0.049). At last clinical follow-up, 28 patients (71.8%) remained stable, 10 (25.6%) improved and 1 patient (2.6%) worsened. Using logistic regression, the relationship between BED and clinical improvement was assessed (OR 0.903, standard error 0.59, coefficient 0.79–1.027, CI −0.10; 0.01; p = 0.14). The highest probability of clinical improvement corresponded to a range of BED values between 56 and 61 Gy. ConclusionPrimary GKR for PCFM is safe and effective. Higher pretherapeutic TV was predictor of volumetric progression. Highest probability of clinical improvement might correspond to a range of BED values between 56 and 61 Gy, although this was not statistically significant. The importance of BED should be further validated in larger cohorts, other anatomical locations and other pathologies.

Posterior petrous face meningiomas presenting with Ménière's-like syndrome: a case series and review of the literature.

Ménière's disease is an inner ear disorder classically characterized by fluctuating hearing loss, tinnitus, and aural fullness accompanied by episodic vertigo. While the pathogenesis of Ménière's remains under debate, histopathological analyses implicate endolymphatic sac dysfunction with inner ear fluid homeostatic dysregulation. Little is known about whether external impingement of the endolymphatic sac by tumors may present with Ménière's-like symptoms. The authors present a case series of 7 patients with posterior fossa meningiomas that involved the endolymphatic sac and new onset of Ménière's-like symptoms and review the literature on this rare clinical entity. A retrospective review of patients undergoing resection of a posterior petrous meningioma was performed at the authors' institution. Inclusion criteria were age older than 18 years; patients presenting with Ménière's-like symptoms, including episodic vertigo, aural fullness, tinnitus, and/or hearing loss; and tumor location overlying the endolymphatic sac. There were 7 cases of posterior petrous face meningiomas involving the vestibular aperture presenting with Ménière's-like symptoms. Imaging and intraoperative examination confirmed no cranial nerve VIII compression or labyrinthine artery involvement accounting for audiovestibular symptoms. Of the 7 patients in the series, 6 experienced significant improvement or resolution of their vertigo, and all 7 had improvement or resolution of their tinnitus after resection. Of the 5 patients who had preoperative hearing loss, 2 experienced improvement or resolution of their ipsilateral preoperative hearing deficit, whereas the other 3 had unchanged hearing loss compared to preoperative evaluation. Petrous face meningiomas overlying the endolymphatic sac can present with a Ménière's syndrome. Early recognition and microsurgical excision of these tumors is critical for resolution of most symptoms and stabilization of hearing loss.

The potential role of biologically effective dose in symptomatic improvement after single Gamma Knife radiosurgery for posterior fossa meningiomas: a series of 46 consecutive cases

The potential role of biologically effective dose in symptomatic improvement after single Gamma Knife radiosurgery for posterior fossa meningiomas: a series of 46 consecutive cases

Intracranial meningioma surveillance using volumetrics from T2-weighted MRI.

The gold standard for imaging of meningiomas is MRI with gadolinium-based contrast agent. Due to increased costs, time, and uncertain chronic effects of gadolinium exposure, use of noncontrast T2-weighted imaging (T2WI) in lieu of contrast-enhanced MRI has been an increasing focus of research across various diagnostic scenarios. The purpose of this study was to evaluate the diagnostic accuracy of T2WI in detecting changes in meningioma tumor volume. Imaging and clinical data were reviewed for 82 consecutive patients undergoing MR-surveillance of intracranial meningioma. Using volumetric-T2WI, two neuroradiologists independently calculated tumor volumes. Measurements were compared to a baseline study contrast-enhanced T1 tumor volume. Using contrast-enhanced sequences as the reference standard, statistical analysis was performed to determine the accuracy of T2WI in detecting changes of meningioma volume. Using only T2WI, readers detected meningioma volume change ≥ 20% in 19/82 patients and volume change <20% in 63/82 patients. Reader accuracy for detecting change in tumor volume on T2WI ≥ 20% was 0.85, sensitivity 0.65, specificity 0.93, positive predictive value (PPV) 0.79, and negative predictive value (NPV) 0.87. For meningiomas >1 ml, reader accuracy for detecting change in tumor volume on T2WI ≥20% was 0.90, sensitivity 0.78, specificity 0.95, PPV 0.88, and NPV 0.91. Change in tumor volume on T2WI ≥20% was detected with 100% accuracy for posterior fossa meningiomas. Inter-reader agreement for all meningiomas was moderate (κ = 0.45) improving to substantial agreement (κ = 0.77) with tumor volumes >1 ml. Volumetric-T2WI detects changes in meningioma volume with comparable accuracy to gold standard T1 postcontrast imaging, particularly with higher tumor volumes and posterior fossa locations.

Predictors of Survival in Subtotally Resected WHO Grade I Skull Base Meningiomas

Simple SummaryRadical excision of meningiomas of the skull base has always been a major surgical challenge because of the complex location and the risk of neurovascular damage related to it. In these cases, the benefits of gross-total resection must be balanced with the quality of life after surgery. In the present study, we investigated a cohort of 212 consecutive patients who underwent partial resection of a benign skull base meningioma in order to find predictors of overall survival (OS). Moreover, we analyzed the clinical outcomes and cases of retreatment for progressive disease. In our case series, advanced age at surgery and a preoperative Karnofsky performance status of <70 were negative predictors of OS. Patients who underwent further procedures did not have reduced OS. Overall, surgical and neurological outcomes of STR skull base meningiomas were worse compared to case series, including also completely resected tumors.Background: Although gross total resection (GTR) is the goal in meningioma surgery, this can sometimes be difficult to achieve in skull base meningiomas. We analyzed clinical outcomes and predictors of survival for subtotally resected benign meningiomas. Methods: A total of 212 consecutive patients who underwent subtotal resection (STR) for benign skull base meningioma between 1990–2010 were investigated. Results: Median age was 57.7 [IQR 18.8] years, median preoperative Karnofsky performance status (KPS) was 80.0 [IQR 20.0], 75 patients (35.4%) had posterior fossa meningioma. After a median follow-up of 6.2 [IQR 7.9] years, retreatment (either radiotherapy or repeated surgery) rate was 16% at 1-year, 27% at 3-years, 34% at 5-years, and 38% at 10-years. Ten patients (4.7%) died perioperatively, 9 (3.5%) had postoperative hematomas, and 2 (0.8%) had postoperative infections. Neurological outcome at final visit was improved/stable in 122 patients (70%). Multivariable analysis identified advanced age and preoperative KPS < 70 as negative predictors for overall survival (OS). Patients who underwent retreatment had no significant reduction of OS. Conclusions: Advanced age and preoperative KPS were independent predictors of OS. Retreatments did not prolong nor shorten the OS. Clinical outcomes in STR skull base meningiomas were generally worse compared to cohorts with high rates of GTR.

Incidence, Clinicopathological Profile and Location - Based Outcome of Intracranial Meningiomas: 10-Year Institutional Study with Review of Literature

Abstract Intracranial meningiomas are the most common extra-axial tumors, representing 15% of all brain tumors. Arising from the arachnoid cells, and common in middle-aged women, 90% meningiomas are benign. We conducted a 10-year study on 183 cases of intracranial meningiomas and observed a lower and decreasing trend; the mean age was 43.3 years but there was also a significant incidence in young females. Parasagittal/falx (29%), sphenoid ridge, convexity meningiomas and middle cranial fossa locations were more common. Histopathologically, meningothelial meningioma was the most common. Benign (WHO I) tumors were found in above 90%, atypical (WHO II) in 5% cases, and malignant (WHO III) in &lt; 4% patients. Most patients underwent Simpsons Grade I excision (35.6%) with dural reconstruction because of late presentations. Posterior fossa meningiomas were mostly benign, while intraventricular ones were mostly malignant with highest postoperation mortality. Mortality in operated patients was 9.8% but was highest in anterior fossa tumors (12.5%).

Monitoring of intracranial venous sinus pressure and prevention for venous air embolism during operation with semi-sitting position

BackgroundVenous air embolism (VAE) during craniotomy operation with semi-sitting position is closely related to intracranial venous pressure. The objective of current study was to explore the relationship between intracranial venous pressure and VAE during operation with semi-sitting position. MethodsBetween April 2018 and January 2019, 25 patients with vestibular schwannoma and 1 patient with posterior fossa meningioma received operation under semi-sitting position. Catheterization at jugular bulb was conducted by puncture of jugular vein with central venous catheter under guidance of ultrasound. The central venous catheter was then connected to a pressure sensor to continuously monitor the jugular bulb pressure (JBP). Both JBP and VAE were continuously monitored during operation to explore the relationship between JBP and intraoperative VAE under semi-sitting position. ResultsUnder supine position, JBP significantly increased when the head was rotated 45° to the right compared with that recorded at neutral head position. Among all 26 patients, VAE occurred in 4 (15.4%) cases during operation including 2 minor VAE and 2 moderate VAE. Among 3 patients with negative JBP relative to atmosphere pressure, 2 occurred VAE during operation; while only 2 patients occurred VAE among other 23 cases whose JBP was positive relative to atmosphere pressure (P = 0.009). ConclusionThe pressure of intracranial sinus could be continuously monitored by catheterization at jugular bulb. JBP monitoring could be used for prediction of intraoperative VAE. The rate of intraoperative VAE was significantly increased when JBP was negative relative to atmosphere pressure.

Risk factors for postoperative pneumonia in patients with posterior fossa meningioma after microsurgery

ObjectivesPostoperative pneumonia (POP) is one of the common complications associated with mortality and morbidity. Even so, it has received little intensive research after microsurgical removal for posterior fossa meningioma (PFM). In this study, we aimed to identify perioperative factors for POP after PFM microsurgery to risk-stratify patients and improve clinical outcomes. Patients and methodsWe retrospectively review on all patients who underwent microsurgical resection (n = 321) for PFM from January 2016 to December 2018. To identify the risk factors for POP, we performed univariate and multivariate analyses successively. Results44 (13.7%) patients were diagnosed as POP. In accordance with univariate analysis, postoperative Glasgow Coma Scale (GCS) score (<13; p < 0.001), tumor size (≥3cm; p < 0.001), procedure duration (≥3 h; p < 0.001), tumor located in anterior or lateral of brainstem (p < 0.001), estimated blood loss (EBL; > 1000ml; p = 0.001) and brainstem shift (p < 0.001) were associated with POP. By multivariate analysis, the first four were independent risk factors for POP. The study also revealed that POP brought about extended duration of postoperative hospitalization. ConclusionThe incidence of POP following PFM microsurgery was significantly high (13.7%). Apart from tumor size (≥3cm) and procedure duration (≥3 h), GCS score (<13) and tumor located in anterior or lateral of brainstem were independent risk factors for POP. Efforts to reduce the duration of surgery, especially among the large tumors located in anterior or lateral of brainstem, may reduce POP rate and hospitalization stay.

Surgery for posterior fossa meningioma: elevated postoperative cranial nerve morbidity discards aggressive tumor resection policy.

Radical excision of meningioma is suggested to provide for the best tumor control rates. However, aggressive surgery for meningiomas located at the posterior cranial fossa may lead to elevated postoperative morbidity of adjacent cranial nerves which in turn worsens patients' postoperative quality of life. Therefore, we analyzed our institutional database with regard to new cranial nerve dysfunction as well as postoperative cerebrospinal fluid (CSF) leakage depending on the extent of tumor resection. Between 2009 and 2017, 89 patients were surgically treated for posterior fossa meningioma at the authors' institution. Postoperative new cranial nerve dysfunction as well as CSF leakage were stratified into Simpson grade I resections with excision of the adjacent dura as an aggressive resection regime versus Simpson grade II-IV tumor removal. Simpson grade I resections revealed a significantly higher percentage of new cranial nerve dysfunction immediately after surgery (39%) compared with Simpson grade II (11%, p = 0.01) and Simpson grade II-IV resections (14%, p = 0.02). These observed differences were also present for the 12-month follow-up (27% Simpson grade I, 3% Simpson grade II (p = 0.004), 7% Simpson grades II-IV (p = 0.01)). Postoperative CSF leakage was present in 21% of Simpson grade I and 3% of Simpson grade II resections (p = 0.04). Retreatment rates did not significantly differ between these two groups (6% versus 8% (p = 1.0)). Elevated levels of postoperative new cranial nerve deficits as well as CSF leakage following radical tumor removal strongly suggest a less aggressive resection policy to constitute the surgical modality of choice for posterior cranial fossa meningiomas.

Chapter 12 - Role of the neurotologist in posterior fossa meningioma surgery

Posterior fossa meningiomas that impinge on structures of the temporal bone or clivus may be difficult to access for optimal resection that maximizes tumor control and minimizes short- and long-term morbidities. To address this challenge, the contemporary neurosurgery-neurotology team works collaboratively by managing patients jointly at every stage of care: preoperative evaluation, intraoperative intervention, and postoperative treatment. The neurotologist is important at all stages of posterior fossa meningioma surgery. First, detailed preoperative evaluation of auditory, facial, vestibular, and lower cranial nerve integrity enables assessment of new neurologic deficit risk, prognosis of functional recovery, and pros and cons of candidate surgical approaches. Second, intraoperative partitioning of surgical steps by provider and adopting an overlapping tumor resection philosophy creates an efficient and confident surgical team built on trust. Third, postoperative closure of cerebrospinal fluid leak and treatment of facial weakness, audiovestibular dysfunction, and voicing and swallowing impairments organized by the neurotologist reduces the impact of negative outcomes. The role of the neurotologist in posterior fossa meningioma surgery is to deliver nuanced evaluative metrics, facilitate shared decision making, perform precise bone and soft tissue microsurgery, and mitigate perioperative morbidities.