Rare variant of large pediatric glioneuronal tumor with novel MYO5A::NTRK3 fusion: illustrative case

BACKGROUND

Glioneuronal tumors (GNTs) comprise a rare class of central nervous system (CNS) neoplasms with varying degrees of neuronal and glial differentiation that predominately affect children and young adults. Within the current 2021 World Health Organization (WHO) classification of CNS tumors, GNTs encompass 14 distinct tumor types. Recently, the use of whole-genome DNA methylation profiling has allowed more precise classification of this tumor group.

OBSERVATIONS

A 3-year-old male presented with a 3-month history of increasing head circumference, regression of developmental milestones, and speech delay. Magnetic resonance imaging of the brain was notable for a large left hemispheric multiseptated mass with significant mass effect and midline shift that was treated with near-total resection. Histological and molecular assessment demonstrated a glioneuronal tumor harboring an MYO5A::NTRK3 fusion. By DNA methylation profiling, this tumor matched to a provisional methylation class known as "glioneuronal tumor kinase-fused" (GNT kinase-fused). The patient was later started on targeted therapy with larotrectinib.

LESSONS

This is the first report of an MYO5A::NTRK3 fusion in a pediatric GNT. GNT kinase-fused is a provisional methylation class not currently included in the WHO classification of CNS tumors. This case highlights the impact of thorough molecular characterization of CNS tumors, especially with the increasing availability of novel gene targeting therapies.

Survival and neurological outcomes following management of intramedullary spinal metastasis patients: a case series with comprehensive review of the literature

Intramedullary spinal cord metastasis (ISCM), though rare, represents a potentially debilitating manifestation of systemic cancer. With emerging advances in cancer care, ISCMs are increasingly being encountered in clinical practice. Herein, we describe one of the larger retrospective single institutional case series on ISCMs, analyze survival and treatment outcomes, and review the literature. All surgically evaluated ISCMs at our institution between 2005 and 2023 were retrospectively reviewed. Demographics, tumor features, treatment, and clinical outcome characteristics were collected. Neurological function was quantified via the Frankel grade and the McCormick score (MCS). The pre- and post-operative Karnofsky performance scores (KPS) were used to assess functional status. Descriptive statistics, univariate analysis, log-rank test, and the Kaplan-Meier survival analysis were performed. A total of 9 patients were included (median age 67 years (range, 26-71); 6 were male). Thoracic and cervical spinal segments were most affected (4 patients each). Six patients (75%) underwent surgical management (1 biopsy and 5 resections), and 3 cases underwent chemoradiation only. Post-operatively, 2 patients had an improvement in their neurological exam with one patient becoming ambulatory after surgery; three patients maintained their neurological exam, and 1 had a decline. There was no statistically significant difference in the pre- and post-operative MCS and median KPS scores in surgically treated patients. Median OS after ISCM diagnosis was 7 months. Absence of brain metastasis, tumor histology (renal and melanoma), cervical/thoracic location, and post-op KPS ≥ 70 showed a trend toward improved overall survival. The incidence of ISCM is increasing, and earlier diagnosis and treatment are considered key for the preservation of neurological function. When patient characteristics are favorable, surgical resection of ISCM can be considered in patients with rapidly progressive neurological deficits. Surgical treatment was not associated with an improvement in overall survival in patients with ISCMs.

Iron-based biomarkers for personalizing pharmacological ascorbate therapy in glioblastoma: insights from a phase 2 clinical trial

BACKGROUND

Pharmacological ascorbate (intravenous delivery reaching plasma concentrations ≈ 20 mM; P-AscH-) has emerged as a promising therapeutic strategy for glioblastoma. Recently, a single-arm phase 2 clinical trial demonstrated a significant increase in overall survival when P-AscH- was combined with temozolomide and radiotherapy. As P-AscH- relies on iron-dependent mechanisms, this study aimed to assess the predictive potential of both molecular and imaging-based iron-related markers to enhance the personalization of P-AscH- therapy in glioblastoma participants.

METHODS

Participants (n = 55) with newly diagnosed glioblastoma were enrolled in a phase 2 clinical trial conducted at the University of Iowa (NCT02344355). Tumor samples obtained during surgical resection were processed and stained for transferrin receptor and ferritin heavy chain expression. A blinded pathologist performed pathological assessment. Quantitative susceptibility mapping (QSM) measures were obtained from pre-radiotherapy MRI scans following maximal safe surgical resection. Circulating blood iron panels were evaluated prior to therapy through the University of Iowa Diagnostic Laboratory.

RESULTS

Through univariate analysis, a significant inverse association was observed between tumor transferrin receptor expression and overall and progression-free survival. QSM measures exhibited a significant, positive association with progression-free survival. Subjects were actively followed until disease progression and then were followed through chart review or clinical visits for overall survival.

CONCLUSIONS

This study analyzes iron-related biomarkers in the context of P-AscH- therapy for glioblastoma. Integrating molecular, systemic, and imaging-based markers offers a multifaceted approach to tailoring treatment strategies, thereby contributing to improved patient outcomes and advancing the field of glioblastoma therapy.

Surgical Management of Craniospinal Axis Solitary Fibrous Tumors: A Single-Institution Case Series and Comprehensive Review of the Literature

BACKGROUND AND OBJECTIVES

Meningeal solitary fibrous tumors (SFTs) comprise 0.4% of primary central nervous system neoplasms and carry metastatic potential. Disease course and optimal management are largely unknown, and there is currently no literature rigorously describing neurological outcomes in surgically managed SFTs. We present one of the largest craniospinal SFT series, analyze patient outcomes, and extensively review the associated literature.

METHODS

All surgically managed SFTs at our institution between January 2005 and March 2023 were retrospectively reviewed. Patient demographics, tumor and radiographic features, treatment, and clinical outcomes were collected. Neurological function was quantified using Frankel grade and Neurologic Assessment in Neuro-Oncology scores. Descriptive statistics, multivariate analysis, log-rank test, and Kaplan-Meier survival analysis were performed.

RESULTS

Twenty-one patients satisfied inclusion criteria. Tumor locations included 15 supratentorial, three infratentorial, and three spinal. All patients underwent surgical resection, and 16 (76.2%) underwent radiation. Six (28.6%) patients had tumor recurrence, and three (14.3%) developed metastasis. Younger age and higher postoperative Frankel grade were significantly associated with increased overall survival (OS) ( P = .011, P = .002, respectively). All patients symptomatically improved or stabilized after surgery, and Neurologic Assessment in Neuro-Oncology score ( P = .001) and functional status significantly improved postoperatively (Karnofsky Performance Status: 65.2 ± 25.2 vs 91.4 ± 13.5, P = .001). Sex, adjuvant radiation, and extent of resection were not significantly associated with OS.

CONCLUSION

SFT of the central nervous system is a rare entity with a variable clinical course. Surgical resection was associated with improved postoperative functional and neurological status. Higher postoperative neurological function was significantly associated with OS. Further studies are warranted to validate a standardized treatment algorithm and investigate the efficacy of adjuvant radiation in SFT.

MRI Detection and Therapeutic Enhancement of Ferumoxytol Internalization in Glioblastoma Cells

Recently, the FDA-approved iron oxide nanoparticle, ferumoxytol, has been found to enhance the efficacy of pharmacological ascorbate (AscH-) in treating glioblastoma, as AscH- reduces the Fe3+ sites in the nanoparticle core. Given the iron oxidation state specificity of T2* relaxation mapping, this study aims to investigate the ability of T2* relaxation to monitor the reduction of ferumoxytol by AscH- with respect to its in vitro therapeutic enhancement. This study employed an in vitro glioblastoma MRI model system to investigate the chemical interaction of ferumoxytol with T2* mapping. Lipofectamine was utilized to facilitate ferumoxytol internalization and assess intracellular versus extracellular chemistry. In vitro T2* mapping successfully detected an AscH--mediated reduction of ferumoxytol (25.6 ms versus 2.8 ms for FMX alone). The T2* relaxation technique identified the release of Fe2+ from ferumoxytol by AscH- in glioblastoma cells. However, the high iron content of ferumoxytol limited T2* ability to differentiate between the external and internal reduction of ferumoxytol by AscH- (ΔT2* = +839% for external FMX and +1112% for internal FMX reduction). Notably, the internalization of ferumoxytol significantly enhances its ability to promote AscH- toxicity (dose enhancement ratio for extracellular FMX = 1.16 versus 1.54 for intracellular FMX). These data provide valuable insights into the MR-based nanotheranostic application of ferumoxytol and AscH- therapy for glioblastoma management. Future developmental efforts, such as FMX surface modifications, may be warranted to enhance this approach further.

Coronavirus disease 2019-associated persistent cough and Chiari malformation type I resulting in acute respiratory failure: illustrative case

BACKGROUND

Chiari malformation type I (CM-I) is the herniation of cerebellar tonsils through the foramen magnum, potentially resulting in the obstruction of cerebrospinal fluid flow and brainstem compression. Sleep-disordered breathing (SDB) is common in patients with CM-I, and symptomatic exacerbations have been described after Valsalva-inducing stressors. Acute decompensation in the setting of coronavirus disease 2019 (COVID-19) has not been described.

OBSERVATIONS

After violent coughing episodes associated with COVID-19 infection, a 44-year-old female developed several months of Valsalva-induced occipital headaches, episodic bulbar symptoms, and worsening SDB, which led to acute respiratory failure requiring mechanical ventilation. Imaging demonstrated 12 mm of cerebellar tonsillar descent below the foramen magnum, dorsal brainstem compression, and syringobulbia within the dorsal medulla. She underwent posterior fossa and intradural decompression with near-complete resolution of her symptoms 6 months postoperatively.

LESSONS

Although CM-I can remain asymptomatic, Valsalva-inducing stressors, including COVID-19 infection, can initiate or acutely exacerbate symptoms, placing patients at risk for CM-I-associated brainstem dysfunction and, in rare cases, acute respiratory failure. Worsening Valsalva maneuvers can contribute to further cerebellar tonsil impaction, brainstem compression, syringomyelia/syringobulbia, and worsening CM-I intradural pathology. Ventilator support and timely decompressive surgery are paramount, as brainstem compression can reduce central respiratory drive, placing patients at risk for coma, neurological deficits, and/or death.

Surgical management of craniospinal axis malignant peripheral nerve sheath tumors: a single-institution experience and literature review

BACKGROUND

Malignant peripheral nerve sheath tumor (MPNST) is an exceedingly rare and aggressive tumor, with limited literature on its management. Herein, we present our series of surgically managed craniospinal MPNSTs, analyze their outcomes, and review the literature.

METHODS

We retrospectively reviewed surgically managed primary craniospinal MPNSTs treated at our institution between January 2005 and May 2023. Patient demographics, tumor features, and treatment outcomes were assessed. Neurological function was quantified using the Frankel grade and Karnofsky performance scores. Descriptive statistics, rank-sum tests, and Kaplan-Meier survival analyses were performed.

RESULTS

Eight patients satisfied the inclusion criteria (4 male, 4 female). The median age at presentation was 38 years (range 15-67). Most tumors were localized to the spine (75%), and 3 patients had neurofibromatosis type 1. The most common presenting symptoms were paresthesia (50%) and visual changes (13%). The median tumor size was 3 cm, and most tumors were oval-shaped (50%) with well-defined borders (75%). Six tumors were high grade (75%), and gross total resection was achieved in 5 patients, with subtotal resection in the remaining 3 patients. Postoperative radiotherapy and chemotherapy were performed in 6 (75%) and 4 (50%) cases, respectively. Local recurrence occurred in 5 (63%) cases, and distant metastases occurred in 2 (25%). The median overall survival was 26.7 months. Five (63%) patients died due to recurrence.

CONCLUSIONS

Primary craniospinal MPNSTs are rare and have an aggressive clinical course. Early diagnosis and treatment are essential for managing these tumors. In this single-center study with a small cohort, maximal resection, low-grade pathology, young age (< 30), and adjuvant radiotherapy were associated with improved survival.

Clinical diagnostic and radiographic features of primary spinal atypical teratoid rhabdoid tumors tumor in a pediatric patient: A case report and review of the literature

Atypical teratoid rhabdoid tumors (ATRTs) are rare embryonal tumors comprising 1-2% of all pediatric CNS neoplasms. Spinal ATRTs are even more uncommon, accounting for 2% of all reported ATRT cases. Despite their rarity, ATRTs affect young children disproportionately and are characterized by a high malignant potential due to a heterogeneous cellular composition and inactivating mutations in the SMARCB1 (90%) and SMARCA4 (10%) genes. A 15-month-old female presented with a 2-week history of decreased lower extremity movement and new-onset need for assistance with ambulation. MRI lumbar spine revealed a contrast-enhancing intradural mass at the L3-L4 level with iso-intensity on T1 and T2 sequences. The patient subsequently underwent subtotal tumor resection (∼80%) given concerns for maintaining neurological function. Final pathology was consistent with spinal ATRT, and she later underwent adjuvant chemoradiation therapy per ACNS0333 protocol. She has since remained in remission with age-appropriate developmental milestones over the past 2 years. ATRTs should be considered in the differential diagnosis of intradural spinal lesions, especially in the pediatric patient population. Clinical course, presentation, and diagnosis is often delayed due to the rarity of these tumors, but contrasted craniospinal MRI is key for diagnosis and histopathology with IHC staining showing loss of INI is confirmatory. While gross total resection is the goal, maximal safe tumor resection should be prioritized in order to preserve neurological function. Adjuvant chemoradiation following gross total/subtotal resection has been shown to significantly improve overall survival.

Surgical outcomes and risk factors for recurrence of myxopapillary ependymoma: a single-center experience

OBJECTIVE

Myxopapillary ependymomas (MPEs) are low-grade, well-circumscribed tumors that often involve the conus medullaris, cauda equina, or filum terminale. They account for up to 5% of all tumors of the spine and 13% of spinal ependymomas, with a peak incidence between 30 and 50 years of age. Because of the rarity of MPEs, their clinical course and optimal management strategy are not well defined, and long-term outcomes remain difficult to predict. The objective of this study was to review long-term clinical outcomes of spinal MPEs and identify factors that may predict tumor resectability and recurrence.

METHODS

Pathologically confirmed cases of MPE at the authors' institution were identified and medical records were reviewed. Demographics, clinical presentation, imaging characteristics, surgical technique, follow-up, and outcome data were noted. Two groups of patients-those who underwent gross-total resection (GTR) and those who underwent subtotal resection (STR)-were compared using the Mann-Whitney U-test for continuous and ordinal variables and the Fisher exact test for categorical variables. Differences were considered statistically significant at p ≤ 0.05.

RESULTS

Twenty-eight patients were identified, with a median age of 43 years at the index surgery. The median postoperative follow-up duration was 107 months (range 5-372 months). All patients presented with pain. Other common presenting symptoms were weakness (25.0%), sphincter disturbance (21.4%), and numbness (14.3%). GTR was achieved in 19 patients (68%) and STR in 9 (32%). Preoperative weakness and involvement of the sacral spinal canal were more common in the STR group. Tumors were larger and spanned more spinal levels in the STR group compared with the GTR cohort. Postoperative modified McCormick Scale grades were significantly higher in the STR cohort compared with the GTR group (p = 0.00175). Seven of the 9 STR patients (77.8%) underwent reoperation for recurrence at a median of 32 months from the index operation, while no patients required reoperation after GTR, for an overall reoperation rate of 25%.

CONCLUSIONS

Findings of this study emphasize the importance of tumor size and location-particularly involvement of the sacral canal-in determining resectability. Reoperation for recurrence was necessary in 78% of patients with subtotally resected tumors; none of the patients who underwent GTR required reoperation. Most patients had stable neurological status postoperatively.

Surgical management of symptomatic vertebral hemangiomas: a single institution experience and literature review

Vertebral hemangiomas (VHs), formed from a vascular proliferation in bone marrow spaces limited by bone trabeculae, are the most common benign tumors of the spine. While most VHs remain clinically quiescent and often only require surveillance, rarely they may cause symptoms. They may exhibit active behaviors, including rapid proliferation, extending beyond the vertebral body, and invading the paravertebral and/or epidural space with possible compression of the spinal cord and/or nerve roots ("aggressive" VHs). An extensive list of treatment modalities is currently available, but the role of techniques such as embolization, radiotherapy, and vertebroplasty as adjuvants to surgery has not yet been elucidated. There exists a need to succinctly summarize the treatments and associated outcomes to guide VH treatment plans. In this review article, a single institution's experience in the management of symptomatic VHs is summarized along with a review of the available literature on their clinical presentation and management options, followed by a proposal of a management algorithm.

Clinical diagnostic and radiographic features of recurrent intracranial malignant triton tumor in an adult: illustrative case

BACKGROUND

Malignant triton tumors (MTTs) are a rare and aggressive type of malignant peripheral nerve sheath tumor identified histologically by focal rhabdomyoblastic differentiation.

OBSERVATIONS

A 37-year-old female with a prior history of Hodgkin lymphoma presented with acute-onset confusion, cognitive deficits, and weakness. Brain magnetic resonance imaging revealed a hemorrhagic intracranial mass later confirmed to be a malignant triton tumor. The patient underwent two resections and several courses of chemoradiation for multiple tumor recurrences and metastases. Unfortunately, despite extensive treatment, she died 2 years after initial presentation from complications of this tumor. Her overall survival (OS) of 26.7 months was double that reported in historical cohorts (OS ∼13 mos).

LESSONS

The diagnosis and treatment of central nervous system MTTs are difficult and require a multidisciplinary team of neurosurgeons, radiologists, and oncologists. Histopathological analysis is required for confirmation of diagnosis. Gross-total resection of tumor and adjuvant radiation therapy have been shown to give patients the highest rates of survival and improved outcomes. Further studies and clinical trials are warranted to investigate the efficacy of chemotherapeutic agents like temozolomide, bevacizumab, and abemaciclib.

Clinical diagnostic and radiographic features of a primary intradural spinal chondrosarcoma in a young adult: illustrative case

BACKGROUND

Mesenchymal chondrosarcoma (MCS) is an aggressive subtype of chondrosarcoma that occurs extremely rarely in the central nervous system. Patients often present with pain or sensorimotor deficits, and resection is considered the gold standard. The role of adjuvant radiation and/or chemotherapy is largely unknown.

OBSERVATIONS

A 22-year-old male presented with a 4-month history of progressive back and bilateral leg pain. He underwent imaging workup with magnetic resonance imaging of the lumbar spine and was found to have an intradural, extramedullary, heterogeneously enhancing mass spanning the L4-5 vertebral levels. Intraoperatively, a lobular, partially calcified mass with a ventral dural attachment displacing the nerve roots laterally was observed. The mass was removed en bloc, and the patient later underwent adjuvant radiotherapy, with no evidence of recurrence 2 years following surgery.

LESSONS

Spinal MCS is extremely rare and often presents with a more aggressive course than conventional chondrosarcoma. Radiological diagnosis is challenging, as the tumor mimics different pathologies. The presence of calcifications, heterogeneous enhancement, and a more rapid clinical course as well as the presence of HEY1::NCOA2 gene fusion, which can be detected by surrogate immunohistochemistry, aids in diagnosis. Resection is the standard of care, and adjuvant radiation may be considered to reduce local recurrence, although further studies are warranted.

Pediatric brainstem abscess successfully treated with stereotactic aspiration: illustrative case

BACKGROUND

Pediatric brainstem abscesses are rare entities that account for 1% of all brain abscesses and, when diagnosed, constitute a neurosurgical emergency.

OBSERVATIONS

A previously healthy 11-year-old male presented with several days of worsening headache, confusion, and ataxia. Brain magnetic resonance imaging (MRI) revealed a midbrain and pons lesion. The patient subsequently had a rapid neurological decline with loss of consciousness and brainstem function. Follow-up MRI revealed significant enlargement of the brainstem lesion with extension into the pons, midbrain, and thalamus, with greater concerns for an abscess rather than a tumor or an inflammatory process. He was taken for an emergent stereotactic aspiration of the abscess, and broad-spectrum antibiotics were initiated. He had neurological improvement, which subsequently declined 5 days later with brain MRI revealing an increase in the brainstem abscess, which required a second stereotactic aspiration. After rehabilitation, he made a significant neurological recovery.

LESSONS

Pediatric brainstem abscesses are rare pathologies, and a high index of suspicion is needed in patients presenting with a brainstem lesion mimicking tumor but with rapid neurological decline despite no other evidence of infection or infectious/inflammatory markers. Stereotactic aspiration is required for large lesions to target the antibiotic treatment and as an adjunct to broad-spectrum antibiotics.

Magnetite nanoparticles as a kinetically favorable source of iron to enhance GBM response to chemoradiosensitization with pharmacological ascorbate

Ferumoxytol (FMX) is an FDA-approved magnetite (Fe3O4) nanoparticle used to treat iron deficiency anemia that can also be used as an MR imaging agent in patients that can't receive gadolinium. Pharmacological ascorbate (P-AscH-; IV delivery; plasma levels ≈ 20 mM) has shown promise as an adjuvant to standard of care chemo-radiotherapy in glioblastoma (GBM). Since ascorbate toxicity mediated by H2O2 is enhanced by Fe redox cycling, the current study determined if ascorbate catalyzed the release of ferrous iron (Fe2+) from FMX for enhancing GBM responses to chemo-radiotherapy. Ascorbate interacted with Fe3O4 in FMX to produce redox-active Fe2+ while simultaneously generating increased H2O2 fluxes, that selectively enhanced GBM cell killing (relative to normal human astrocytes) as opposed to a more catalytically active Fe complex (EDTA-Fe3+) in an H2O2 - dependent manner. In vivo, FMX was able to improve GBM xenograft tumor control when combined with pharmacological ascorbate and chemoradiation in U251 tumors that were unresponsive to pharmacological ascorbate therapy. These data support the hypothesis that FMX combined with P-AscH- represents a novel combined modality therapeutic approach to enhance cancer cell selective chemoradiosentization in the management of glioblastoma.

Vertebral hemangiomas: Diagnosis and management. A single center experience

OBJECTIVE

Vertebral hemangiomas (VH) are common benign lesions involving the spine. Owing to the multiplicity of treatments, the management of VH has not always been consistent. In this retrospective review of a single center experience, indications and options available for the treatment of VH are outlined.

PATIENTS AND METHODS

This is a retrospective review of 71 cases of VH managed at our institution between 2005 and 2019. Sixty of these cases were managed non-operatively, with 11 cases undergoing operative intervention. Of the 11 cases that underwent surgery, there were 2 cervical cases and 9 in the thoracic spine. Ten cases were symptomatic, and 1 incidental. Three patients presented with localized pain, and the remaining 7 had neurological deficit. Decompression with maximal resection of the hemangioma was undertaken in 10 cases, and vertebroplasty in 1.

RESULTS

Of the 60 patients who were managed non-operatively, 13 patients had presented with back/neck pain, with the remaining 47 patients being asymptomatic and diagnosed incidentally. Among the 13 symptomatic patients, all were offered surgical intervention for pain management, but given lack of severity of symptoms, all had opted for conservative approaches of pain control. In the 11 patients who underwent surgery, the preoperative diagnosis of VH was accurate in all but 1 case. There were 2 cervical cases treated with corpectomy. One patient was treated with vertebroplasty, and the remaining 8 with decompression. Radiation was used in 2 cases. Of the 10 patients undergoing decompression, 7 patients had improvement of the neurologic deficit, with resolution of pain in the remaining 3. None of our cases demonstrated deterioration.

CONCLUSION

VH are often discovered incidentally during evaluation of spinal pain. Except in rare cases, the diagnosis of VH is made correctly from the radiographic and MRI studies. Observation for the asymptomatic lesion is appropriate. For VH presenting with deficit or intractable pain, decompressive surgery is recommended. Radiation is appropriate in cases of recurrent VH.

Intraoperative Shoulder Traction as Cause of C5 Palsy: Magnetic Resonance Imaging Study

OBJECTIVE

During surgery, shoulder traction is often used for better fluoroscopic imaging of the lower cervical spine. Traction on the C5 root has been implicated as a potential cause of C5 palsy after cervical spine surgery. Using magnetic resonance imaging, this study was undertaken to determine the impact of upper extremity traction on the C5 root orientation.

METHODS

In this study, 5 subjects underwent coronal magnetic resonance imaging of the cervical spine and left brachial plexus. Using a wrist restraint, sequential traction on the left arm with 10, 20, and 30 lb. was applied. Measurements of the angle between the spinal axis and C5 nerve root and the angle between the C5 nerve root and the upper trunk of the brachial plexus were obtained. The measurements were taken by a trained neuroradiologist and analyzed for significance.

RESULTS

The angle between the C5 nerve root and the vertical spinal axis remained within 3 and 4 degrees of the mean and was not found to be associated with increased traction weight (P = 0.753). The angle between the C5 root and the upper trunk increased with increasing weight and was found to be statistically significant (P = 0.003).

CONCLUSIONS

While the cause of C5 palsy is likely multifactorial, this study provides evidence that, in the awake volunteer, upper extremity traction leads to C5 root and upper trunk tension. These results suggest that shoulder traction in the anesthetized patient could lead to tension of the C5 nerve root and subsequent injury and palsy.

Methods and Devices for Posterior Ventriculoperitoneal Shunt Placement Surgery: 25 Years of Iterative Refinement

BACKGROUND

The posterior ventriculoperitoneal shunt (VPS) placement procedure is technically efficient and cosmetically appealing. The main limitations of the posterior approach relate to the technical challenges associated with accurately placing the ventricular catheter. In this report, we describe methods and simple devices used for posterior VPS surgery that have evolved over a >25-year period to enhance catheter placement accuracy and reduce complication rates.

OBJECTIVE

We describe the combination of methods and customized devices used at a single institution to perform posterior VPS surgery. Results are presented for the most recent 11-year epoch, along with a description of sources of technical errors and plans for further methodologic refinements.

MATERIALS AND METHODS

The medical records and imaging studies of 468 patients undergoing posterior VPS, from 2007 to 2018 were reviewed. Ventricular catheter placement accuracy data were collected and complications were identified and recorded.

RESULTS

Optimal ventricular catheter placement was achieved in 98.29%. Of the remaining 1.71%, one half (0.85%) required acute revision surgery. Four patients (0.85%) developed new neurologic deficits following surgery; 2 were related to intraparenchymal hemorrhages and 2 (0.43%) as a result of a misplaced catheter. The deficits resulting from poor catheter placement were transient. The complication rates due to causes other than catheter placement accuracy compared favorably with those reported previously in the literature.

CONCLUSIONS

Using the methods and devices described in this series, posterior VPS operations can be performed safely with a high degree of ventricular catheter placement accuracy.

Abstract TP561: The Effects of Recanalization of Chronically Occluded Internal Carotid Artery on Patients' Neurocognition

Objective: To evaluate pre and postop cerebral hemodynamics and the effects it has on neurocognitive outcomes in patients with chronically occluded internal carotid artery (COICA) who have undergone successful recanalization.

Methods: Patients with symptomatic COICA who underwent revascularization technique using either angioplasty and stenting (AS) or a hybrid of carotid endarterectomy and AS are included in this analysis.

Results: From January 2016 to June of 2018, 31 subjects underwent revascularization. Only 5 subjects (6 COICA) had CTP and MoCA scores pre and post revascularization. All 5 subjects had very large penumbra involving the ipsilateral hemisphere, which has resolved postop. No permanent complications were associated with the procedure. All patients have objective improvement in their neurocognitive outcomes (pre MoCA: 19.8±2.4, post MoCA: 27±1.6; p-0.0038).

Conclusions: CTP can guide in patient selections for recanalization. Successful recanalization lead to improvement in CTP parameters and neurocognitive functions.

Abstract WMP31: Plasma Soluble Human Elastin Fragments as an Intra-Aneurysmal Localized Biomarker for Ruptured Intracranial Aneurysms

Background: Fragmentation of the tunica media is a hallmark of intracranial aneurysm formation, often leading to aneurysmal progression and subsequent rupture. The objective of this study is to determine the plasma level of elastin fragments in the lumen of ruptured versus unruptured human intracranial aneurysms.

Methods: One hundred consecutive patients with/without ruptured saccular intracranial aneurysms undergoing endovascular coiling or stent-assisted coiling were recruited. Blood samples were collected from the lumen of intracranial aneurysm using a micro-catheter. The tip of the microcatheter was placed inside the aneurysm’s sac in close proximity to the inner wall of the dome. Plasma levels of elastin fragments were measured using an ELISA-based method.

Results: The mean plasma level of soluble human elastin fragments was significantly greater in ruptured aneurysms when compared to non-ruptured aneurysms (102.0 ± 15.5 vs. 39.3 ± 9.6 ng/ml, P<0.001). The mean plasma level of soluble human elastin fragments did not have significant correlation with age, gender, size, or aneurysm location.

Conclusions: The present study revealed that a significantly higher concentration of soluble human elastin fragments in the lumen of ruptured intracranial aneurysms when compared to non-ruptured ones.

Hybrid Surgery for Internal Carotid Artery Revascularization

OBJECTIVE

The management of chronic complete internal carotid artery (ICA) occlusion (COICA) has been challenging. Endovascular procedures have been performed with variable success and risks, depending on the type of occlusion and distal revascularization. We present a novel hybrid procedure to recanalize the ICA when previous endovascular interventions have failed or been deemed too risky.

METHODS

Two patients presented with symptomatic COICA after maximal medical management. They were deemed at high risk of endovascular intervention and/or previous endovascular attempts had failed. Thus, they had indications for a hybrid procedure.

RESULTS

A hybrid technique was used to create a stump by surgical endarterectomy, followed by recanalization using an endovascular approach via femoral access. We have described the technique in detail. Postoperative computed tomography perfusion scanning showed normalization of the mean transient time, cerebral blood volume, and cerebral blood flow compared with the preoperative findings. Cerebral angiography showed successful recanalization of the ICA. Neither patient experienced any complications.

CONCLUSION

A hybrid technique is feasible and should be considered for patients with COICA in whom maximal medical management has failed and who have a high-risk profile for endovascular intervention or in whom previous endovascular attempts have failed.

Plasma Soluble Human Elastin Fragments as an Intra-Aneurysmal Localized Biomarker for Ruptured Intracranial Aneurysm

Background Fragmentation of the tunica media is a hallmark of intracranial aneurysm formation, often leading to aneurysmal progression and subsequent rupture. The objective of this study is to determine the plasma level of elastin fragments in the lumen of ruptured versus unruptured human intracranial aneurysms. Methods and Results One hundred consecutive patients with/without ruptured saccular intracranial aneurysms undergoing endovascular coiling or stent-assisted coiling were recruited. Blood samples were collected from the lumen of intracranial aneurysm using a microcatheter. The tip of the microcatheter was placed inside the aneurysm's sac in close proximity to the inner wall of the dome. Plasma levels of elastin fragments were measured using an ELISA -based method. Mean plasma level of soluble human elastin fragments was significantly greater in ruptured aneurysms when compared with nonruptured aneurysms (102.0±15.5 versus 39.3±9.6 ng/mL; P<0.001). Mean plasma level of soluble human elastin fragments did not have significant correlation with age, sex, size, or aneurysm location. Conclusions The present study revealed that a significantly higher concentration of soluble human elastin fragments in the lumen of ruptured intracranial aneurysms when compared with nonruptured ones.