Citations

BACKGROUND: Minimally invasive surgical techniques have reinvigorated the role of surgical options for spontaneous intracranial hematomas; however, they are limited by the lack of real-time feedback on the extent of hematoma evacuation. OBJECTIVE: To describe the development of a MRI-guided catheter-based aspiration system, the ClearPoint Pursuit Neuroaspiration Device (ClearPoint Neuro) and validation in phantom models. METHODS: In this preclinical experimental trial, 8 phantom brains with skull models were created to simulate an intracranial hematoma with 2 clot sizes, 30 cc (small clot) and 60 cc (large clot). After registration, the aspiration catheter (Pursuit device) was aligned to the desired planned trajectory. The aspiration of the clot was performed under real-time MRI scan in 3 orthogonal views. The primary end point was reduction of the clot volume to less than 15 cc or 70% of the original clot volume. RESULTS: Successful completion of clot evacuation was achieved in all models. The average postaspiration clot volume was 9.5 cc (8.7 cc for small clots and 10.2 cc for large clots). The average percentage reduction of clot volume was 76.3% (range 58.7%-85.2%). The average total procedure time (from frame registration to final postaspiration clot assessment) was 50 min. The average aspiration time was 6.9 min. CONCLUSION: This preclinical trial confirms the feasibility and efficacy of MRI-guided aspiration under real-time image guidance in simulation models for intracranial hematoma. Clinical use of the system in patients would further validate its efficacy and safety.

OBJECTIVE Multiple meningiomas (MMs) occur in as many as 18% of patients with meningioma, and data on progression-free survival (PFS) are scarce. The objective of this study was to explore the influence of the number of lesions and clinical characteristics on PFS in patients with WHO grade I meningiomas. METHODS The authors retrospectively reviewed the records of all adults diagnosed with a meningioma at their three main sites from January 2009 to May 2020. Progression was considered the time from diagnosis until radiographic growth of the originally resected meningioma. A secondary analysis was performed to evaluate the time of diagnosis until the time to second intervention (TTSI). Univariable and multivariable analyses were conducted to assess whether the number of lesions or any associated variables (age, sex, race, radiation treatment, tumor location, and extent of resection) had a significant impact on PFS and TTSI. RESULTS Eight hundred thirty-eight patients were included. Use of a log-rank test to evaluate PFS and TTSI between a single and multiple lesions showed a significantly shorter progression for MM (p < 0.001 and p < 0.001, respectively). Multivariable Cox regression analysis showed significantly inferior PFS on MM compared to a single lesion (hazard ratio [HR] 2.262, 95% confidence interval [CI] 1.392–3.677, p = 0.001) and a significantly inferior TTSI for patients with MM when compared to patients with a single meningioma (HR 2.377, 95% CI 1.617–3.494, p = 0.001). By testing the number of meningiomas as a continuous variable, PFS was significantly inferior for each additional meningioma (HR 1.350, 95% CI 1.074–1.698, p = 0.010) and TTSI was significantly inferior as well (HR 1.428, 95% CI 1.189–1.716, p < 0.001). African American patients had an inferior PFS when compared to non-Hispanic White patients (HR 3.472, 95% CI 1.083–11.129, p = 0.036). CONCLUSIONS The PFS of meningiomas appears to be influenced by the number of lesions present. Patients with MM also appear to be more prone to undergoing a second intervention for progressive disease. Hence, a closer follow-up may be warranted in patients who present with multiple lesions. These results show a decreased PFS for each additional lesion present, as well as a shorter PFS for MM compared to a single lesion. When assessing associated risk factors, African American patients showed an inferior PFS, whereas older age and adjuvant therapy with radiation showed an improved PFS.

Abstract INTRODUCTION Multiple meningiomas (MM) occurs in up to 18% of meningioma patients and progression data are scarce. The objective of this study is to explore the influence of number of lesions and clinical characteristics on progression-free survival (PFS) and time to a second intervention (TTSI) in patients with WHO grade 1 meningiomas. METHODS We retrospectively reviewed records of all adults diagnosed with a meningioma at our three main sites from January 2009 to May 2020. Progression was considered as time from diagnosis until radiographic progression of the originally resected meningioma. A secondary analysis was carried to evaluate the time from diagnosis to time of a second intervention. Univariable and multivariable analyses were conducted to assess whether number of lesions or any associated variables (age, sex, race, radiation, location, and extent of resection) had a significant impact on PFS and TTSI. RESULTS 838 patients were included. Log-rank test evaluating PFS and TTSI between single and multiple lesions showed significantly shorter progression for MM (p&lt; 0.001 and p&lt; 0.001, respectively). Multivariable Cox regression showed significantly inferior PFS on MM vs. single lesion (HR 2.262 [CI 95%, 1.392-3.677], p=0.001) and a significantly inferior TTSI for patients with MM vs. single meningioma (HR 2.377 [CI 95%, 1.617 – 3.494], p=0.001). When input as a continuous variable, PFS was significantly inferior for each additional meningioma (HR 1.350 [CI 95% 1.074-1.698], p=0.010) and TTSI is significantly inferior as well (HR 1.428 [CI 95% 1.189 – 1.716], p&lt; 0.001). African-Americans had an inferior PFS when compared to Non-Hispanic White patients (HR 3.472 [CI 95% 1.083-11.129], p=0.036). CONCLUSION The PFS of meningiomas is influenced by the number of lesions present. Patients with MM are more prone to undergo a second intervention for progressive disease. Hence, a closer follow-up may be warranted in patients who present with multiple lesions.

OBJECTIVE Recent studies have proposed resection of the T2 FLAIR hyperintensity beyond the T1 contrast enhancement (supramarginal resection [SMR]) for IDH–wild-type glioblastoma (GBM) to further improve patients’ overall survival (OS). GBMs have significant variability in tumor cell density, distribution, and infiltration. Advanced mathematical models based on patient-specific radiographic features have provided new insights into GBM growth kinetics on two important parameters of tumor aggressiveness: proliferation rate (ρ) and diffusion rate (D). The aim of this study was to investigate OS of patients with IDH–wild-type GBM who underwent SMR based on a mathematical model of cell distribution and infiltration profile (tumor invasiveness profile). METHODS Volumetric measurements were obtained from the selected regions of interest from pre- and postoperative MRI studies of included patients. The tumor invasiveness profile (proliferation/diffusion [ρ/D] ratio) was calculated using the following formula: ρ/D ratio = (4π/3) 2/3 × (6.106/[V T2 1/1 − V T1 1/1 ]) 2 , where V T2 and V T1 are the preoperative FLAIR and contrast-enhancing volumes, respectively. Patients were split into subgroups based on their tumor invasiveness profiles. In this analysis, tumors were classified as nodular, moderately diffuse, or highly diffuse. RESULTS A total of 101 patients were included. Tumors were classified as nodular (n = 34), moderately diffuse (n = 34), and highly diffuse (n = 33). On multivariate analysis, increasing SMR had a significant positive correlation with OS for moderately and highly diffuse tumors (HR 0.99, 95% CI 0.98–0.99; p = 0.02; and HR 0.98, 95% CI 0.96–0.99; p = 0.04, respectively). On threshold analysis, OS benefit was seen with SMR from 10% to 29%, 10% to 59%, and 30% to 90%, for nodular, moderately diffuse, and highly diffuse, respectively. CONCLUSIONS The impact of SMR on OS for patients with IDH–wild-type GBM is influenced by the degree of tumor invasiveness. The authors’ results show that increasing SMR is associated with increased OS in patients with moderate and highly diffuse IDH–wild-type GBMs. When grouping SMR into 10% intervals, this benefit was seen for all tumor subgroups, although for nodular tumors, the maximum beneficial SMR percentage was considerably lower than in moderate and highly diffuse tumors.

OBJECTIVE Available data on management of sacral arteriovenous fistulas (sAVFs) are limited to individual case reports and small series. Management includes observation, endovascular embolization, or surgical ligation, with no clear guidelines on the optimal treatment modality. The authors’ objective was to report their multiinstitutional experience with management of sAVF patients, including clinical and radiographic characteristics and postprocedural outcomes. METHODS The electronic medical records of patients with a diagnosis of spinal arteriovenous fistula treated from January 2004 to December 2019 at the authors’ institutions were reviewed, and data were summarized using descriptive statistics, including percentage and count for categorical data, median as a measure of central tendency for continuous variables, and interquartile range (IQR) as a measure of dispersion. RESULTS A total of 26 patients with sAVFs were included. The median (IQR) age was 65 (57–73) years, and 73% (n = 19) of patients were male. Lower-extremity weakness was the most common presenting symptom (n = 24 [92%]), and half the patients (n = 13 [50%]) reported bowel and bladder sphincter dysfunction. The median (IQR) time from symptom onset to treatment was 12 (5.25–26.25) months. Radiographically, all patients had T2 hyperintensity at the level of the conus medullaris (CM) (n = 26 [100%]). Intradural flow voids were identified in 85% (n = 22) of patients. The majority of the lesions had a single identifiable arterial feeder (n = 19 [73%]). The fistula was located most commonly at the S1 level (n = 13 [50%]). The site where the draining vein connects to the pial venous plexus was seen predominantly at the lumbar level (n = 16 [62%]). In total, 29 procedures were performed: 10 open surgeries and 19 endovascular embolization procedures. Complete occlusion was achieved in 90% (n = 9) of patients after open surgery and 79% (n = 15) after endovascular embolization. Motor improvement was seen in 68% of patients (n = 15), and bladder and bowel function improved in 9 patients (41%). At last follow-up, 73% (n = 16) of patients had either resolution or improvement of the pretreatment intramedullary T2 signal hyperintensity. CONCLUSIONS T2 hyperintensity of the CM and a dilated filum terminale vein are consistent radiographic signs of sAVF, and delayed presentation is common. Complete occlusion was achieved in almost all patients after surgery, and endovascular embolization was effective in 70% of the patients. Further studies are needed to determine the best treatment modality based on case-specific characteristics.

Abstract Arteriovenous malformations (AVMs) are highly complex vascular lesions characterized by abnormal connections between arteries and an intervening nidus. Definitive and safe treatment of AVMs may require the combination of multiple treatment modalities to address the various complex features of the AVM. 1 Endovascular embolization can be used as an adjuvant to surgery in order to control deep feeders, reduce flow, and address high-risk features such as aneurysms. In addition, by progressively reducing the AVM flow, staged embolization can lead to normalization of peri-AVM hemodynamics and therefore may decrease the risk of postresection hemorrhage. 2,3 In this operative video, we present a case of a 41-yr-old female who presented with progressively worsening left-sided hemiparesis. Magnetic resonance imaging (MRI) and angiography revealed a complex right fronto-parietal AVM with significant associated edema, likely due to the vascular steal phenomenon. The area of edema, which included the motor cortex, was thought to be at high risk for postoperative hemorrhage from normal perfusion pressure breakthrough. We therefore decided to proceed with staged presurgical embolization to gradually normalize the perilesional hemodynamics, and therefore possibly reduce the risk of postoperative morbidity. The patient underwent 3 embolization sessions at 6-wk intervals. An MRI after the last embolization showed near-complete resolution of the fluid-attenuated inversion-recovery (FLAIR) signal around the AVM. Microsurgical resection was performed on the day after the last embolization. The patient tolerated the procedure well and was discharged at her neurological baseline with mild contralateral hemiparesis, which has continued to improve at follow-up. Postoperative angiography showed complete resection of the AVM. The patient consented to the procedure as shown in this operative video and gave informed written consent for use of her images in publication.

OBJECTIVE High-grade spinal glioma (HGSG) is a rare but aggressive tumor that occurs in both adults and children. Histone H3 K27M mutation correlates with poor prognosis in children with diffuse midline glioma. However, the role of H3 K27M mutation in the prognosis of adults with HGSG remains unclear owing to the rarity of this mutation, conflicting reports, and the absence of multicenter studies on this topic. METHODS The authors studied a cohort of 30 adult patients with diffuse HGSG who underwent histological confirmation of diagnosis, surgical intervention, and treatment between January 2000 and July 2020 at six tertiary academic centers. The primary outcome was the effect of H3 K27M mutation status on progression-free survival (PFS) and overall survival (OS). RESULTS Thirty patients (18 males and 12 females) with a median (range) age of 50.5 (19–76) years were included in the analysis. Eighteen patients had H3 K27M mutation–positive tumors, and 12 had H3 K27M mutation–negative tumors. The median (interquartile range) PFS was 3 (10) months, and the median (interquartile range) OS was 9 (23) months. The factors associated with increased survival were treatment with concurrent chemotherapy/radiation (p = 0.006 for PFS, and p ≤ 0.001 for OS) and American Spinal Injury Association grade C or better at presentation (p = 0.043 for PFS, and p < 0.001 for OS). There were no significant differences in outcomes based on tumor location, extent of resection, sex, or H3 K27M mutation status. Analysis restricted to HGSG containing necrosis and/or microvascular proliferation (WHO grade IV histological features) revealed increased OS for patients with H3 K27M mutation–positive tumors (p = 0.017). CONCLUSIONS Although H3 K27M mutant–positive HGSG was associated with poor outcomes in adult patients, the outcomes of patients with H3 K27M mutant–positive HGSG were somewhat more favorable compared with those of their H3 K27M mutant–negative HGSG counterparts. Further preclinical animal studies and larger clinical studies are needed to further understand the age-dependent effects of H3 K27M mutation.

Abstract Surgical approaches to lesions of the fourth ventricle (FV) have been modified over the years to reduce the complications associated with splitting the inferior cerebellar vermis (ICV) and disrupting the brainstem and critical surrounding structures. 1-4 Two common approaches to lesions of this region include the transvermian approach (TVA) and telovelar approach (TeVA). 2 The TVA was initially considered the conventional route of access to lesions of the FV 1 but has been associated with significant risks, including possible gait ataxia and dysarthria. 3 The TeVA is advantageous, as it involves dissection along natural clefts and division of non-neural tissue and provides good exposure of the superolateral recess with modest exposure of the rostral FV. The TeVA approach can be augmented by opening the tonsilouvular fissures (TUFs). This added dissection allows greater lateral and superior exposure with less need for retraction. In this operative video, we demonstrate a case in which we augmented the TeVA with a TUF dissection to access a dorsal pontine cavernous malformation. We performed a midline suboccipital craniotomy with a C1 posterior laminectomy. TUF dissection was followed by division of the tela choroidea (TC), which allowed for more lateral exposure of the FV and excellent visualization of the cavernous malformation without the need to traverse neural tissue. TeVA augmented by TUF dissection provided adequate access to the dorsal pons for complete resection of the cavernous malformation. The patient consented to the procedure as shown in this operative video and gave informed written consent for use of her images in publication. Anatomic images provided by courtesy of © The Rhoton Collection. http://rhoton.ineurodb.org/. Video © Mayo Foundation for Medical Education and Research, 2021. Used with permission.