Predictive Evolution Factors of Incidentally Discovered Suspected Low-Grade Gliomas: Results From a Consecutive Series of 101 Patients

International audienceBackground: Incidentally discovered suspected diffuse low-grade gliomas (LGGs) on brain imaging pose a challenge to neurosurgeons. Modern surgical series of LGGs favor early prophylactic surgery with a maximal extent of resection. However, some nonevolutive lesions may mimic LGGs on magnetic resonance imaging (MRI).Objective: To determine objective criteria to advocate surgical resection of an incidentally discovered suspected LGG based upon MRI findings.Methods: The prospective cohort of patients referred to our institution for an incidental finding suggestive of LGG was retrospectively reviewed. Stable lesions underwent systematic serial MRI follow-up, while evolutive lesions underwent prophylactic surgery under awake conditions. Initial clinico-radiological features were compared between stable and evolutive lesions in order to determine predictive criteria of further evolution.Results: Among 101 patients referred for surgical resection of incidentally discovered suspected LGG in our center, 19 patients (18.8%) had nonevolutive MRI lesions after a mean follow-up of 46.9 ± 34.9 mo. Insular topography (P = .003), higher mean volume at discovery (19.2 vs 5.2 cm3, P < .001), and adjacent sulcal effacement (P = .001) were associated with evolutive lesions. Histopathological diagnosis of LGG was confirmed in all surgical cases.Conclusion: Increasing volume is an effective predictor of LGG diagnosis in incidental MRI findings, as all patients who subsequently underwent surgery had confirmed histopathological diagnosis of diffuse glioma. Approximately 18.8% of incidental findings were stable over time. Insular topography, adjacent sulcal effacement, and volume greater than 4.5 cm3 were predictive of further radiological progression. These significant elements will help neurosurgeons to define personalized strategies in this complex setting of incidental discovery

Mouse Models in Meningioma Research: A Systematic Review

International audienceMeningiomas are the most frequent primitive central nervous system tumors found in adults. Mouse models of cancer have been instrumental in understanding disease mechanisms and establishing preclinical drug testing. Various mouse models of meningioma have been developed over time, evolving in light of new discoveries in our comprehension of meningioma biology and with improvements in genetic engineering techniques. We reviewed all mouse models of meningioma described in the literature, including xenograft models (orthotopic or heterotopic) with human cell lines or patient derived tumors, and genetically engineered mouse models (GEMMs). Xenograft models provided useful tools for preclinical testing of a huge range of innovative drugs and therapeutic options, which are summarized in this review. GEMMs offer the possibility of mimicking human meningiomas at the histological, anatomical, and genetic level and have been invaluable in enabling tumorigenesis mechanisms, including initiation and progression, to be dissected. Currently, researchers have a range of different mouse models that can be used depending on the scientific question to be answered

Bow Hunter's Syndrome: Surgical Vertebral Artery Decompression Guided by Dynamic Intraoperative Angiography

International audienceBACKGROUND: Bow hunter's syndrome is a symptomatic vertebrobasilar insufficiency resulting from a rotational stenosis or occlusion of a dominant vertebral artery (VA). The VA is dynamically compressed by cervical osteoarthritis (discovertebral structure or osteophytes) during head rotation or neck extension. Diagnosis is based on dynamic computed tomography angiography and confirmed with dynamic catheter angiography. Surgery tends to be the best treatment option in most cases. Dynamic intraoperative assessment of VA decompression seems to improve surgical results but remains poorly evaluated in the literature. CASE DESCRIPTION: A 70-year-old man with bow hunter's syndrome related to left VA compression by C3-4 osteophyte protrusion presented with syncopal episodes during left head rotation. Bow hunter's syndrome was successfully managed with an anterior transuncal surgical decompression of the left VA and C3-4 fusion. Surgical decompression was guided by dynamic intraoperative catheter angiography and secured with an intra-arterial remodeling balloon placed just before surgery. The patient was symptom-free after surgery. CONCLUSIONS: Surgical decompression guided by dynamic intraoperative catheter angiography leads to selective VA release and allows real-time assessment of the efficacy of the decompression. This multidisciplinary treatment involving neurosurgical and neuroradiologic teams is a simple and effective treatment. Dynamic intraoperative catheter angiography is an essential guide to perform selective decompression of the VA, and implementation of an intra-arterial remodeling balloon can improve the safety of surgery making this method valuable compared with other intraoperative assessment techniques, such as Doppler ultrasound and indocyanine green fluorescent videography

Electrocorticography Is Not Necessary During Awake Brain Surgery for Gliomas

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Low Rate of Intraoperative Seizures During Awake Craniotomy in a Prospective Cohort with 374 Supratentorial Brain Lesions: Electrocorticography Is Not Mandatory

International audienceOBJECTIVE:Awake craniotomy (AC) in brain lesions has allowed an improvement of both oncologic and functional results. However, intraoperative seizures (IOSs) were reported as a cause of failure of AC. Here, we analyze the incidence, risk factors, and consequences of IOSs in a prospective cohort of 374 ACs without electrocorticography (ECoG).METHODS:We performed a prospective study including all patients who underwent AC for an intra-axial supratentorial cerebral lesion from 2009-2014 in our department. Occurrence of IOS was analyzed with respect to medical and epilepsy history, tumor characteristics, operative technique, and postoperative outcomes.RESULTS:The study comprised 374 patients with a major incidence of low-grade glioma (86%). Most of the patients (83%) had epilepsy history before surgery (20% had intractable seizures). Preoperative mean Karnofsky performance scale (KPS) score was 91. IOSs occurred in 13 patients (3.4%). All IOSs were partial seizures, which quickly resolved by irrigation with cold Ringer lactate. No procedure failed because of IOS, and the rate of aborted AC whatever the cause was nil. Mean stimulation current intensity for cortical and subcortical mapping was 2.25 ± 0.6 mA. Presurgical refractory epilepsy was not associated with a higher incidence of IOS. Three months after surgery, no patients had severe or disabling permanent worsening, even within the IOS group (mean KPS score of 93.7).CONCLUSIONS:AC for intra-axial brain lesion can be safely and reproducibly achieved without ECoG, with a low rate of IOS and excellent functional results, even in patients with preoperative intractable epilepsy

Is hospital information system relevant to detect surgical site infection? Findings from a prospective surveillance study in posterior instrumented spinal surgery

International audienceOBJECT:Spinal instrumentation has a high rate of surgical site infection (SSI), but results greatly vary depending on surveillance methodology, surgical procedures, or quality of follow-up. Our aim was to study true incidence of SSI in spinal surgery by significant data collection, and to compare it with the results obtained through the hospital information system.METHODS:This work is a single center prospective cohort study that included all patients consecutively operated on for spinal instrumentation by posterior approach over a six-month period regardless the etiology. For all patients, a "high definition" prospective method of surveillance was performed by the infection control (IC) department during at least 12 months after surgery. Results were then compared with findings from automatic surveillance though the hospital information system (HIS).RESULTS:One hundred and fifty-four patients were included. We found no hardly difference between "high definition" and automatic surveillance through the HIS, even if HIS tended to under-estimate the infection rate: rate of surgical site infection was 2.60% and gross SSI incidence rate via the hospital information system was 1.95%. Smoking and alcohol consumption were significantly related to a SSI.CONCLUSION:Our SSI rates to reflect the true incidence of infectious complications in posterior instrumented adult spinal surgery in our hospital and these results were consistent with the lower levels of published infection rate. In-house surveillance by surgeons only is insufficiently sensitive. Further studies with more patients and a longer inclusion time are needed to conclude if SSI case detection through the HIS could be a relevant and effective alternative method

Robot-assisted spine surgery: feasibility study through a prospective case-matched analysis

International audiencePURPOSE:While image guidance and neuronavigation have enabled a more accurate placement of pedicle implants, they can inconvenience the surgeon. Robot-assisted placement of pedicle screws appears to overcome these disadvantages. However, recent data concerning the superiority of currently available robots in assisting spinal surgeons are conflicting. The aim of our study was to evaluate the percentage of accurately placed pedicle screws, inserted using a new robotic-guidance system.METHOD:20 Patients were operated on successively by the same surgeon using robotic assistance (ROSA™, Medtech) (Rosa group 10 patients, n = 40 screws) or by the freehand conventional technique (Freehand group 10 patients, n = 50 screws). Patient characteristics as well as the duration of the operation and of exposure to X rays were recorded.RESULTS:The mean age of patients in each group (RG and FHG) was 63 years. Mean BMI and operating time among the RG and FHG were, respectively, 26 and 27 kg/m(2), and 187 and 119 min. Accurate placement of the implant (score A and B of the Gertzbein Robbins classification) was achieved in 97.3% of patients in the RG (n = 36) and in 92% of those in the FHG (n = 50). Four implants in the RG were placed manually following failed robotic assistance.CONCLUSION:We report a higher rate of precision with robotic as compared to the FH technique. Providing assistance by permanently monitoring the patient's movements, this image-guided tool helps more accurately pinpoint the pedicle entry point and control the trajectory. Limitations of the study include its small sized and non-randomized sample. Nevertheless, these preliminary results are encouraging for the development of new robotic techniques for spinal surgery

GAB1 overexpression identifies Hedgehog‐activated anterior skull base meningiomas

International audienceAimsMutations activating the Hedgehog (Hh) signalling pathway have been described in anterior skull base meningiomas, raising hope for the use of targeted therapies. However, identification of Hh-activated tumours is hampered by the lack of a reliable immunohistochemical marker. We report the evaluation of GAB1, an immunohistochemical marker used to detect Hh pathway activation in medulloblastoma, as a potential marker of Hh-activated meningiomas.MethodsGAB1 staining was compared to SMO mutation detection with Sanger and NGS techniques as well as Hh pathway activation study through mRNA expression level analyses in a discovery set of 110 anterior skull base meningiomas and in a prospective validation set of 21 meningiomas.ResultsUsing an expression score ranging from 0 to 400, we show that a cut-off score of 250 lead to excellent detection of Hh pathway mutations (sensitivity 100%, specificity 86%). The prospective validation set confirmed the excellent negative predictive value of GAB1 to exclude Hedgehog independent meningiomas. We describe a large series of 32 SMO-mutant meningiomas and define multiple ways of Hh activation, either through somatic mutations or associated with mutually co-exclusive SHH (Sonic Hedgehog) or IHH (Indian Hedgehog) overexpression independent of the mutations.ConclusionThe assessment of GAB1 expression by an immunohistochemical score is a fast and cost-efficient tool to screen anterior skull base meningiomas for activation of the Hedgehog pathway. It could facilitate the identification of selected cases amenable to sequencing for hedgehog pathway genes as predictive markers for targeted therapy

Partial Vertebrectomies without Instrumented Stabilization During En Bloc Resection of Primary Bronchogenic Carcinomas Invading the Spine: Feasibility Study and Results on Spine Balance

International audienceOBJECTIVE:It is unknown whether spinal instrumentation is required to prevent deformity after partial vertebrectomy in the treatment of primary bronchogenic carcinomas invading the spine (PBCIS). In this study, we focus on the postoperative spine deformity in patients who underwent operation for partial vertebrectomies without instrumentation during en bloc PBCIS resection. Our objective was to determine whether deformity depends on the type of vertebral resection and if any vertebral resection threshold can be observed to justify additional spinal instrumentation.METHODS:This is a retrospective study, including all patients with PBCIS operated without spinal instrumentation from 2009 to 2018. Partial vertebrectomies were classified into categories A, B, and C depending on vertebral resection. Patients had long-term radiologic follow-up to assess the spine deformity evolution.RESULTS:Eighteen patients were included. The median follow-up was 27 months. Four patients underwent a secondary posterior instrumentation surgical procedure due to progressive spinal deformity. A low-risk group of deformation was characterized as type A resection and type B resection on less than 3 vertebrae.CONCLUSIONS:There are no validated criteria to justify a systematic spinal instrumentation when performing a partial vertebrectomy during en bloc resection of PBCIS. Performed alone without spine instrumentation, both type A and type B resections on less than 3 resected vertebrae were not subject to sagittal and coronal deformity even after a long follow-up, emphasizing that a systematic stabilization is not needed in this low-risk group. These results could help to reduce the perioperative morbidity of these procedures that are usually long and complex

Herpes Simplex Encephalitis Shortly After Surgery for a Secondary Glioblastoma: A Case Report and Review of the Literature

International audienceBackground: Herpes simplex encephalitis (HSE) and glioblastoma multiforme (GBM) co-occurrence has been described in few cases presenting immunocompromised status related to chemotherapy or chemoradiotherapy. Focal encephalitis over surgical edge of resection occurring shortly after GBM resection is rarely reported, and such infection has never been reported in low-grade glioma with secondary malignant transformation (i.e., secondary GBM). Here, we report a case of HSE misdiagnosed in the early postoperative course following a secondary GBM resection. We also provide a review of the literature about HSE occurring after glioma surgery. Case description: We report a case of an acute HSE with a fatal outcome occurring shortly after surgery for a secondary GBM. The patient presented with hyperthermia 12 days after the surgery and was treated with empirical antibiotics. She later suffered from seizure and neurologic deterioration, leading to death despite delayed antiviral administration. Magnetic resonance imaging revealed considerable fluid-attenuated inversion-recovery signal progression at the edge of the surgical resection and polymerase chain reaction amplification of herpes simplex virus (HSV) 1 DNA was positive. Conclusions: Clinicians should be aware of the existing co-occurrence between HSV infections and GBM during the postoperative course. Cerebrospinal fluid analysis with HSV polymerase chain reaction testing should be promptly undertaken, and some keys clinical elements should justify early empirical treatment, including acyclovir administration. The significant prognostic implication of HSE complicating GBM must raise the attention of neurosurgeon and neuro-oncologist about this entity