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BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm. OBJECTIVE To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT). METHODS HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during follow-up, aneurysm occlusion stability, and clinical outcome at final follow-up. RESULTS A total of 600 patients were randomized (HES, n = 297 and BPC, n = 303), including 28% with ruptured aneurysms. Recurrence occurred in 11 (4.4%) subjects in the HES arm and 44 (15.4%) subjects in the BPC arm (P = .002). While the initial occlusion rate was higher with BPC, the packing density and both major and minor recurrence rates were in favor of HES. Secondary endpoints including adverse events, retreatment, hemorrhage, mortality, and clinical outcome did not differ between arms. CONCLUSION Coiling of small-to-medium aneurysms with second-generation HES resulted in less recurrence when compared to BPC, without increased harm. These data further support the use of the second-generation HES for the embolization of intracranial aneurysms. VIDEO ABSTRACT

Ischemic stroke is the leading cause of disability and the fourth-leading cause of mortality in the United States. Intracranial atherosclerotic disease (ICAD) is one of the major causes of ischemic stroke in the general population. The pathophysiology is not yet fully understood and, therefore, the optimal treatment modality has yet to be defined. The results of the two most recent large-scale randomized trials (VISSIT and SAMMPRIS) favored maximal medical therapy as a first-line treatment. However, the failure rate of medical therapy is about 12% at 1 year and increases to as high as 22% at 2 years. Furthermore, first generation devices were used in SAMMPRIS with a high reported periprocedural stroke rate. All these factors have led to a renewed interest in endovascular approaches to ICAD, specifically with the development of newer techniques and devices. In addition, even though the current data support medical management for this disease, there is a subset of patients who seem to benefit from angioplasty and stenting. Proper selection criteria must be met, however. Because of the complexity of the pathophysiology, the ever-improving endovascular options, and the high failure rate of current treatment paradigms, further studies are required to advance our understanding of ICAD. Only then will we be able to select the optimal treatment for each subset of patients.

The study of quality of life (QOL) in patients with asymptomatic diseases receiving interventional treatment provides an essential metric for the assessment of procedural benefits in the surgical patient population. In this study, we analyzed QOL data collected from patients with unruptured intracranial aneurysms (UIAs) before and after endovascular coiling in the HEAT Trial, alongside a systematic review on QOL in unruptured brain aneurysms.HEAT was a randomized controlled trial comparing recurrence rates in aneurysms treated with either bare platinum coils or hydrogel coils. Patients enrolled in this trial completed a short form-36 (SF-36) QOL questionnaire before treatment and at the 3- to 12- and 18- to 24-month follow-ups. The change in QOL before and after treatment was assessed. Regression analysis evaluated the effect of select baseline characteristics on QOL change.A total of 270 patients were eligible for analysis. There was an increase in the role physical (P = 0.043), vitality (P = 0.022), and emotional well-being (P0.001) QOL components at the 18- to 24-month follow-up compared with baseline scores. Regression analysis showed that age younger than 60 and absence of serious adverse events were associated with improved social functioning and vitality. The literature review showed a mixed effect of intervention on QOL in patients with UIAs.Our analysis has revealed that patients with 3- to 14-mm UIAs had improvements in some physical and emotional components of QOL at 18-24 months following aneurysm coiling in the HEAT study. The literature remains indeterminate on this issue. Further studies are needed to better understand the effects of the diagnosis of UIAs and their treatment on QOL.

Background Cerebrovascular bypass surgical procedures require highly developed dexterity and refined bimanual technical skills. To attain such a level of prowess, neurosurgeons and residents have traditionally relied on “flat” models (without depth of field), such as chicken wings, live rats, silicone vessels, and other materials that stray far from the reality of the operating room, albeit more accessible. We have explored the use of a hybrid ex vivo simulator that takes advantage of the availability of placenta vessels and retains the complexity of surgery performed on a human skull to create a more realistic method for the development of cerebrovascular bypass surgical skills. Methods Twelve ex vivo simulators were constructed using 3 human placentas and 1 synthetic human skull for each. Face, content, construct, and concurrent validity were assessed by 12 neurosurgeons (6 trained vascular surgeons and 6 general neurosurgeons) and compared with those of other bypass models. Results The fidelity grade was ranked as low (Linkert scale score, 1–2), medium (score, 3), and high (score, 4–5). The face and content validity of the model showed high fidelity to superficial temporal artery–middle cerebral artery bypass surgery. Construct validity showed that cerebrovascular neurosurgeons had better performance, and concurrent validity highlighted that all surgical steps were present. Conclusion The simulator was found to have strong face and content, construct, and concurrent validity for microsurgical cerebrovascular training, allowing for simulation of all surgical steps of the bypass procedure. The hybrid simulator seems to be a promising method for shortening the bypass surgery learning curve. However, more studies are required to evaluate the predictive validity of the model.

Objective To determine the accuracy of ultrasound guidance compared to palpation in performing carpometacarpal joint injections in cadavers. Design In all, 36 carpometacarpal joints were randomized to either ultrasound-guided or palpation-based injections, with 1 cc of blue latex solution injected into each joint. The specimens were then dissected and the distribution of the latex was assessed by two independent, blinded raters. Injection accuracy was evaluated on a four-point quartile rating scale of 1–4, corresponding to the amount of the latex solution within the joint (1 = 0–25%, 2 = 26–50%, 3 = 51–75%, 4 = 76–100%). Inter-rater reliability was a secondary measure. Results The mean rating of accuracy was 2.1 for both palpation-based and ultrasound-guided injections. There was no statistically significant difference in accuracy between the two injectors. Chi-square analysis testing differences in accuracy for the two conditions was not statistically significant. The Cronbach’s alpha for rater 2 was 0.74, which represents an acceptable level of reliability. A Friedman’s Chi-square for the two raters was 2.3 ( p = 0.13), indicating no significant difference between raters. Conclusion Ultrasound guidance did not improve the accuracy of carpometacarpal joint injections in cadavers. However, the high inter-rater reliability attests to the value of the novel assessment scale.

Arteriovenous malformations (AVMs) of the brain are abnormal connections between the arterial and venous cerebral vasculature that often lead to intracranial hemorrhage (ICH). The diagnosis of AVMs often takes place in the setting of ICH, however, there is no clear consensus on how to manage critically ill, comatose patients and whether it is best to treat the lesion initially. We present an initial treatment strategy that is focused on the management of intracranial hypertension by the means of decompressive craniectomy (DC) coupled with delayed AVM management. We retrospectively reviewed the medical records of three patients who arrived with ICH, obliterated cisterns, and midline shifts greater than 5mm from ruptured AVMs. Each of these patients received a DC, with later definite treatment for their AVMs and cranioplasties. We reported the preoperative and postoperative clinical status of patients using Glasgow Coma Scale (GCS) outcomes as well as physical exam findings. All three patients were transferred to the intensive care immediately after DC and had significant clinical improvement 15 days post-craniectomy. All patients underwent definitive AVM treatment within 6 weeks of the initial procedure. One patient was treated with endovascular-only embolization while the other two received surgical treatment. Patients showed a significant improvement in neurological status and clinical outcome. Decompressive hemicraniectomies may have a positive impact on mortality and neurological outcomes for select patients with cerebral hemorrhage originating from vascular malformations, especially in low-resource scenarios.

IMPORTANCE: Diagnostic errors can lead to the initial misdiagnosis of optic nerve sheath meningiomas (ONSM), which can lead to vision loss. OBJECTIVE: To identify factors contributing to the initial misdiagnosis of ONSM. DESIGN, SETTING, AND PARTICIPANTS: We retrospectively reviewed 35 of 39 patients with unilateral ONSM (89.7%) who were seen in the tertiary neuro-ophthalmology practice at Emory University School of Medicine between January 2002 and March 2017. The Diagnosis Error Evaluation and Research taxonomy tool was applied to cases with missed/delayed diagnoses. EXPOSURES: Evaluation in a neuro-ophthalmology clinic. MAIN OUTCOMES AND MEASURES: Identifying the cause of diagnostic errors for patients who initially received a misdiagnosis who were found to have ONSM. RESULTS: Of 35 patients with unilateral ONSM (30 women [85.7%]; mean [SD] age, 45.26 [15.73] years), 25 (71%) had a diagnosis delayed for a mean (SD) of 62.60 (89.26) months. The most common diagnostic error (19 of 25 [76%]) was clinician assessment failure (errors in hypothesis generation and weighing), followed by errors in diagnostic testing (15 of 25 [60%]). The most common initial misdiagnosis was optic neuritis (12 of 25 [48%]), followed by the failure to recognize optic neuropathy in patients with ocular disorders. Five patients who received a misdiagnosis (20%) underwent unnecessary lumbar puncture, 12 patients (48%) unnecessary laboratory tests, and 6 patients (24%) unnecessary steroid treatment. Among the 16 patients who initially received a misdiagnosis that was later correctly diagnosed at our institution, 11 (68.8%) had prior magnetic resonance imaging (MRI) results that were read as healthy; 5 (45.5%) showed ONSM but were misread by a non-neuroradiologist and 6 (54.5%) were performed incorrectly (no orbital sequence or contrast). Sixteen of the 25 patients (64%) had a poor visual outcome. CONCLUSIONS AND RELEVANCE: Biased preestablished diagnoses, inaccurate funduscopic examinations, a failure to order the correct test (MRI brain/orbits with contrast), and a failure to correctly interpret MRI results were the most common sources of diagnostic errors and delayed diagnosis with worse visual outcomes and increased cost (more visits and tests). Easier access to neuro-ophthalmologists, improved diagnostic strategies, and education regarding neuroimaging should help prevent diagnostic errors.

Spinal dural arteriovenous fistulas are the most common vascular malformations of the spine. They are localized in the sacral spine in 5% to 14% of the cases. They can be fed by the median or the lateral sacral arteries. These lesions present with nonspecific symptoms such as radiculopathy and/or myelopathy, which often leads to a delay in diagnosis. In this video, we present the case of a 65-yr-old gentleman with a lateral sacral dural arteriovenous fistula. The patient was referred to our institution after the outside facility workup was nondiagnostic. He presented with spastic paraparesis and bilateral radiculopathy. After patient informed consent was obtained, we performed a spinal diagnostic angiogram with catheterization and angiography of the internal iliac artery, which revealed the fistula. Onyx (Medtronic, Dublin, Ireland) embolization was performed, which led to a complete occlusion of the fistula. The patient had complete neurological recovery, and at 2-yr follow-up, imaging remained negative for a fistula. In this video, we discuss the nuances and key points related to the epidemiology, diagnosis, and treatment of lateral sacral fistulas.1-3.

The localization of arteriovenous malformations (AVMs) intraoperatively in the setting of an acute intracerebral hemorrhage (ICH) is crucial to avoid damage of delicate vascular structures that may even further exacerbate the bleed. Currently, surgical mapping using preoperative angiographic is the standard of practice. We report the use of intraoperative ultrasound for the diagnosis and localization of an AVM in the case of a 61-year-old female with reported iodine contrast allergy and previous severe reaction, in a setting with limited resources, without other imaging options or timely transfer to another facility readily available. Immediate surgical care was warranted to avoid further deterioration of the patient; intraoperative diagnosis and localization of the suspected underlying lesion were done using ultrasound. The ultrasound display showed tubular anechoic intertwined structures that demonstrated bidirectional flow, which is suggestive of an AVM. The intraoperative diagnosis allowed the surgeon to avoid an inadvertent approach to the vascular malformation nidus or vessels, which could have further complicated the case. We believe that intraoperative ultrasound may be valuable for the neurosurgeons today in many settings. Despite the fact that this case occurred in a scenario with limited resources and no other imaging method (such as magnetic resonance imaging (MRI), magnetic resonance angiography (MRA)) available, we advise readers not to rely solely on intraoperative ultrasound.

Background For optimizing high-grade glioma resection, 5-aminolevulinic acid is a reliable tool. However, its efficacy in low-grade glioma resection remains unclear. Objective To study the role of 5-aminolevulinic acid in low-grade glioma resection and assess positive fluorescence rates and the effect on the extent of resection. Methods A systematic review of PubMed, Google Scholar, and Cochrane was performed from the date of inception to February 1, 2019. Studies that correlated 5-aminolevulinic acid fluorescence with low-grade glioma in the setting of operative resection were selected. Studies with biopsy only were excluded. Positive fluorescence rates were calculated. The quality index of the selected papers was provided. No patient information was used, so Institutional Review Board approval and patient consent were not required. Results A total of 12 articles met the selection criteria with 244 histologically confirmed low-grade glioma patients who underwent microsurgical resection. All patients received 20 mg/kg body weight of 5-aminolevulinic acid. Only 60 patients (n = 60/244; 24.5%) demonstrated visual intraoperative 5-aminolevulinic acid fluorescence. The extent of resection was reported in 4 studies; however, the data combined low- and high-grade tumors. Only 2 studies reported on tumor location. Only 3 studies reported on clinical outcomes. The Zeiss OPMI Pentero microscope was most commonly used across all studies. The average quality index was 14.58 (range: 10-17), which correlated with an overall good quality. Conclusion There is an overall low correlation between 5-aminolevulinic acid fluorescence and low-grade glioma. Advances in visualization technology and using standardized fluorescence quantification methods may further improve the visualization and reliability of 5-aminolevulinic acid fluorescence in low-grade glioma resection.

This is the case of an 86-yr-old gentleman who presented with left facial pain exacerbated by eating, drinking, chewing, and shaving (distribution: V2, V3). The patient was diagnosed with trigeminal neuralgia and was refractory to medications. Imaging showed a superior cerebellar artery (SCA) loop adjacent to the trigeminal nerve root entry zone and a decision to perform a microvascular decompression of the fifth nerve was presented to the patient. After patient informed consent was obtained, a standard 3 cm × 3 cm retrosigmoid craniotomy was performed with the patient in a supine head turned position and in reverse Trendelenburg. The arachnoid bands tethering the SCA to the trigeminal nerve were sharply divided. A slit was then made in the tentorium and a 3 mm fenestrated clip was then used to secure the transposed SCA away from the trigeminal nerve. The SCA proximal to this was slightly patulous in its course so a small amount of a fibrin glue was also used to secure the more proximal SCA to the tentorium. The patient was symptom-free postoperatively and no longer required medical therapy. Additionally, imaging was consistent with adequate separation of the nerve from adjacent vessels.1-5.

Background Of the minimally invasive “keyhole” alternatives to the pterional region, the supraorbital eyebrow approach is the most widely adopted. Yet it can prove disadvantageous when a more direct lateral microsurgical trajectory of attack to the Sylvian fissure and anterior middle fossa are needed. Objective The extended lateral orbital (XLO) approach was designed to be direct and minimally invasive, with the sphenoid ridge at the center of exposure. Methods Five injected cadaver heads were used for anatomic study of the XLO approach. The anatomic course of the frontalis branch of facial nerve was studied in relation to the XLO incision. Following XLO incision, the bone exposure was measured. The intracranial microsurgical exposure was assessed subjectively. Application of the technique in representative clinical operative cases is provided. Results The frontalis nerve was protected in the subgaleal fat pad, with an average minimum distance of 2.3 cm from the XLO incision. The mean calvarial area exposure was 4.95 cm2 and consistently centered on the sphenoid ridge. Excellent access to ipsilateral Sylvian's fissure, perisylvian regions, and supra-/parasellar structures was possible. The main limitations related to exposure of the posterior Sylvian fissure and the expected limitations of microsurgical instrument manipulation from a smaller craniotomy. Conclusions The XLO approach is a minimally invasive keyhole approach to the pterional region that affords a unique lateral trajectory via a craniotomy centered on the sphenoid ridge. Excellent exposure to properly selected lesions is possible. The incision is at a safe distance from the frontalis branch and shows excellent cosmetic healing.

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Modern intraaxial tumor surgery has evolved from static three-dimensional point localization within the cranium with frame-based systems into highly accurate, user-friendly frameless stereotactic systems. However, brain shift was realized early on as a limitation which renders frameless stereotaxy less useful toward the later stages of tumor resection. Intraoperative MRI has proven to be useful in updating intraoperative images and thus maintaining the accuracy of navigation. The exploitation of tumor cell biochemistry led to adaptation of tumor fluorescence-guided surgery and has revolutionized high-grade glioma surgery. Furthermore, direct cell visualization techniques in tumor margins, such as with Raman spectroscopy or confocal microscopy, are exciting prospects that have the potential to take navigation-based tumor surgery to the next level. Future advances in intraaxial tumor navigation are likely from integration of multimodal MRI (including functional MRI and tractography) with intraoperative brain shift correction, awake functional mapping, and augmented reality platforms.

Background Cranial base chordomas are complex lesions centered on the clivus that surgically can be approached from either a midline or a lateral corridor. Objective To compare the surgical outcomes from midline versus lateral approaches by conducting a meta-analysis of the literature. Methods Studies were identified between 2000 and 2018. The primary outcome was gross total resection (GTR) rate. The secondary outcomes were recurrence rate and rates of cerebrospinal fluid (CSF) leak and new cranial nerve palsy. Odds ratios were calculated with a random-effect model using studies describing both approaches. An indirect (proportion) meta-analysis was performed pooling studies describing either of the approaches. Individual patient data were analyzed for differences in GTR or recurrence rate with different tumor extensions. Results Thirty-three studies were found suitable for indirect meta-analysis and 10 studies for direct meta-analysis. The overall odds of GTR with a midline approach compared with a lateral approach was 0.83 (95% confidence interval [CI], –0.43 to 1.62). The odds ratios for recurrence, CSF leak, and new cranial nerve palsy were 0.82 (95% CI, 0.26–2.56), 1.49 (95% CI, 0.14–15.5), and 0.14 (95% CI, 0.04–0.56), respectively. With individual patient data analysis, no statistically significant difference was observed in GTR or recurrence rates between the 2 approaches with different tumor extensions. Conclusions The meta-analysis did not show any significant difference in GTR or recurrence rates between the midline versus lateral approaches. Tumor extension to different compartments did not affect the GTR or recurrence rates with either approach. In terms of complications, CSF leak rate was higher in midline approaches and cranial nerve palsy was higher in lateral approaches.

This is a surgical video that sheds light on the utility of a new imaging modality GLOW800 (Leica Microsystems, Wetzlar, Germany) in resection of vascular tumors. We describe the surgical resection of posterior fossa hemangioblastoma in 2 different patients after informed consent was obtained. In the first case no intraoperative angiographic imaging was used, while in the second case GLOW800 was used. Because of its ability to overlay the augmented reality view on the surgical field, it allowed for localization of highly vascular tumors as seen in the second patient. In addition, it helped in the confirmation of complete resection of the lesion. Another advantage of GLOW800 was that it allowed safe resection of the lesion in and around highly eloquent areas with a narrow surgical corridor (Video 1).

Neurovascular compression is a potential, yet rare cause of vertigo and unilateral tinnitus. Despite the high success rate of microvascular decompression (MVD) in other vascular compression syndromes, the outcome reported after MVD of the vestibulocochlear nerve is variable.1,2 The presence of combined symptoms of tinnitus and vertigo treated by MVD has demonstrated a higher predictive value for success.3 In this video, we present the case of a 68-year-old male who presented with vertigo and tinnitus refractory to medical management and vestibular therapy. Audiologic evaluation was normal apart from mild sensorineural hearing loss. Vestibular testing was suggestive of uncompensated right peripheral vestibulopathy. Magnetic resonance imaging with fast imaging employing steady-state acquisition sequences revealed vascular compression by the right anteroinferior cerebellar artery (AICA) at the cisternal component of vestibulocochlear nerve. After a multidisciplinary discussion, a microvascular decompression was performed through a right retrosigmoid craniotomy. The AICA was mobilized off the vestibulocochlear nerve and was secured to the petrous dura using a fenestrated clip. Indocyanine green angiography with Glow-800 was conducted before and after AICA transposition to confirm adequate flow through the mobilized vessel. Postoperatively, the patient's vestibular symptoms improved significantly. This case demonstrates that microvascular decompression can provide a satisfactory outcome in patients with unilateral tinnitus and vertigo associated with vascular compression in appropriately selected cases (Video 1).

This 3D video showcases the surgical techniques for patients with proximal junctional kyphosis. The surgical repair for patients with proximal junctional kyphosis is an individualized approach depending on patient history and imaging with adequate surgical measurements. This video will shed light on two cases with proximal junctional kyphosis and the method taken for their repair. The first case is of an 11-year-old female known to have osteogenesis imperfecta and status post T5–L3 posterior spinal fusion with segmental instrumentation. The patient underwent change of older instruments and scoliosis repair, with full correction on postoperative x-ray. The second patient is a 16-year-old male known to have cerebral palsy and kyphoscoliosis status post spinal fusion. The patient underwent scoliosis repair surgery with replacement of old instrumentation and scoliosis correction.The video can be found here: https://youtu.be/f5iLwqbU26Q.

We present the case of a 62-yr-old female who presented with ground-level fall and new onset of left-sided weakness of 30 min duration. CT angiogram revealed right ICA pseudo-occlusion and thrombus filling the right proximal M1 segment of the right MCA. On detailed neurological exam patient was noted to have NIHSS of 25. Patient was started on IV TPA infusion and was taken to interventional angiography suite after an informed consent was obtained. Diagnostic angiography was performed which demonstrated critical stenosis of the right proximal internal carotid artery. Right carotid artery stenting and balloon angioplasty of the carotid stent with distal embolic protection device was performed. Post carotid stent angiogram once again confirmed proximal right M1 pseudo-occlusion in the right MCA distribution. The clot was removed using a stent retriever, thus achieving complete recanalization (TICI 3) of the right cerebral hemisphere. The patient returned to baseline neurological status and a 1 mo follow-up diagnostic angiogram revealed patent carotid stent. Following the case presentation, we present the nuances of acute ischemic stroke management of large vessel occlusion with an emphasis on technical nuances, recent published guidelines1 and the literature.2-8.

In this video, we present the case of a 61-year-old female who was brought to the emergency department after she had partial complex seizures. Computed tomography and magnetic resonance imaging of the brain revealed a right temporal lobe mass, which was initially thought to be a tumor. The patient was therefore referred to us for further management. The round nature of the lesion raised suspicion for an aneurysm. Computed tomography angiography was performed, followed by a diagnostic conventional cerebral angiogram, and confirmed the presence of a giant thrombosed aneurysm. Giant aneurysms represent 3%-5% of all cerebral aneurysms.1 They are more common in females with a ratio of 2:1 to 3:1.1 They have a high risk of rupture up to 50% in the posterior circulation and 40% in the anterior circulation over 5 years according to the International Study of Unruptured Intracranial Aneurysms Investigators.2,3 Their treatment can be complex and treacherous. Treatment options vary widely from parent artery sacrifice in select cases to clip reconstruction to an array of endovascular approaches such as flow diversion. In some cases a combination of both open and endovascular approaches might be necessary.4-8 In our case, we opted for an open surgical clip reconstruction. A superior temporal artery-middle cerebral artery bypass was attempted to allow for trapping of the aneurysm without risking ischemic complication distal to it. Unfortunately, the patient's vessels were too atherosclerotic to maintain patency. A strategy was then devised, which consisted of cutting the dome of the aneurysm and clearing the distal two thirds of the clot ("tulip technique") and then completing thrombus resection under temporary occlusion. Once clot removal was completed, the aneurysm was clipped using the "shingle clip cut clip" technique (Video 1). The patient's postoperative course was uneventful, and the patient remained seizure free.

BACKGROUND 5-aminolevulinic acid is a reliable tool for optimizing high-grade glioma resection. However, its efficacy in low-grade glioma resection remains unclear. OBJECTIVE To study the role of 5-aminolevulinic acid in low-grade glioma resection and assess positive fluorescence rates and effect on the extent of resection. METHODS A systematic review of PubMed, Google Scholar, and Cochrane was performed from the date of inception to February 1, 2019. Studies that correlated 5-aminolevulinic acid fluorescence with low-grade glioma in the setting of operative resection were selected. Studies with biopsy only were excluded. Positive fluorescence rates were calculated. Quality index of the selected papers using the Downs and Black criteria checklist was provided. RESULTS Twelve articles met the selection criteria with 244 histologically-confirmed low-grade glioma patients who underwent microsurgical resection. All patients received 20 mg/kg body weight of 5-aminolevulinic acid. Only 60 patients (n=60/244; 24.5%) demonstrated visual intra-operative 5-aminolevulinic acid fluorescence. The extent of resection was reported in 4 studies, however, the data combined low- and high-grade tumors. Only 2 studies reported on tumor location. Only 3 studies reported on clinical outcomes. The Zeiss OPMI Pentero microscope was most commonly used across all studies. The average quality index was 14.58 (range: 10–17) which correlated with an overall good quality. CONCLUSION There is an overall low correlation between 5-aminolevulinic acid fluorescence and low-grade glioma. Advances in visualization technology and using standardized fluorescence quantification methods may further improve the visualization and reliability of 5-aminolevulinic acid fluorescence in low-grade glioma resection.

Introduction Recurrence remains a limitation of endovascular aneurysm treatment. The Hydrogel Coil (Microvention, Aliso Viejo, CA) that constitutes a platinum core surrounded by a hydrogel coat was developed to enhance packing density and healing within an aneurysm, with the ultimate goal of improving durability rates. The first-generation HydroCoil showed positive results in terms of aneurysm recurrence; however, widespread adoption was limited by technical challenges. For this purpose, a second-generation Hydrogel Coil (HES – HydroCoil Embolic System) was developed. Its design allows for longer working times (20–30 min), and an ease of use which seems to parallel platinum coils. The New Generation Hydrogel Endovascular Aneurysm Treatment (HEAT) Trial aimed to compare the second generation HydroCoil Embolic System with bare platinum coils in a study of 600 subjects. Methods This is a randomized, controlled, multicenter, post-market clinical trial. Subjects between 18 and 75 years of age with ruptured or unruptured intracranial aneurysms (3–14 mm in size) who were amenable to endovascular treatment were randomized in a 1:1 fashion to each of the treatment arms in 46 participating sites. The protocol stipulated that subjects randomized to the HES arm be treated with at least 90% second-generation hydrogel coils and subjects randomized to the bare platinum arm strictly receive bare platinum coil. The primary endpoint of the trial was aneurysm recurrence over an 18 month follow-up period. Secondary endpoints included packing density, initial occlusion, retreatment, hemorrhage from the treated aneurysm, mortality, and aneurysm occlusion stability. Results Enrollment began on June 20, 2012 and ended in January 15, 2016. Among screened subjects (n=3971), 600 patients were randomized (HES n=297 and bare platinum n=303). Aneurysm size was similar in both arms with a mean of 6.86 mm in the HES group and 6.93 mm in the bare platinum group. Recanalization rates were 4.4% for the HES arm and 15.4% for the bare platinum arm (p Conclusion In the HEAT trial, the second-generation Hydrogel Coil is found to be superior to the bare platinum coil in reducing aneurysm recurrence rates. In addition, long-term clinical assessment was similar between both arms. Our study results support the preferential use of Hydrogel coils for the endovascular treatment of intracranial aneurysms. Disclosures K. Abi-Aad: 1; C; MicroVention, Inc. J. Ward: 1; C; MicroVention, Inc. J. Kniss: 1; C; MicroVention, Inc. R. Aoun: None. C. Krishna: None. M. Welz: None. F. Tian: None. B. Bendok: 1; C; MicroVention, Inc.

Aneurysm recanalization constitutes a limitation in the endovascular treatment of intracranial aneurysms using conventional bare platinum coils. The development of platinum coils coupled with hydrogel polymers aimed at decreasing the rates of recurrence by way of enhanced coil packing density and biological healing within the aneurysm. While enhanced occlusion and durability has been shown for the first generation hydrogel coils, their use was limited by technical challenges. Less data is available regarding the second-generation hydrogel coils which have been designed to perform like bare platinum coils. The new generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT) is a multicenter, randomized controlled trial that compares the health outcomes of the second-generation HydroCoil Embolic System with bare platinum coils in the endovascular intracranial aneurysms. The primary endpoint is aneurysm recurrence, defined as any progression on the Raymond aneurysm scale, over a 24-month follow-up period. Secondary endpoints include packing density, functional independence, procedural adverse events, mortality rate, initial complete occlusion, aneurysm retreatment, hemorrhage from treated aneurysm, and any aneurysm recurrence. Patient recruitment initiated in June 2011 and ended in January 2016 in 46 centers. Six hundred eligible patients diagnosed with an intracranial aneurysm, ruptured or unruptured were randomly assigned to one of the two treatment arms. The HEAT trial compares the durability, imaging, and clinical outcomes of the second-generation hydrogel versus bare platinum coils in the endovascular treatment of ruptured or unruptured intracranial aneurysms. The results of this trial may further inform current endovascular treatment guidelines based on observed long-term outcomes.

Roberts Bartholow, a physician, born and raised in Maryland, was a surgeon and Professor in Medicine who had previously served the Union during the Civil War. His interest in scientific research drove him to perform the first experiment that tested the excitability of the human brain cortex. His historical experiment on one of his patients, Mary Rafferty, with a cancerous ulcer on the skull, was one of his great accomplishments. His inference from this experiment and proposed scientific theory of cortical excitation and localization in humans was one of the most critically acclaimed topics in the medical community, which attracted the highest commendation for the unique discovery as well as criticism for possible ethical violations. Despite that criticism, his theory and methods of cortical localization are the cornerstone of modern brain mapping and have, in turn, led to countless medical innovations.

Cavernomas at the posterolateral pontomesencephalic surface can be approached from a lateral infratentorial supracerebellar corridor. In this surgical video, we demonstrate two cases of brainstem cavernomas resected through a lateral supracerebellar infratentorial approach. A supine position with lateral turn of the head was used along with significant reverse Trendelenburg to allow the cerebellum to fall away with gravity from the tentorium. After exposure of the posterior surface of the brainstem between the tentorium and the superior cerebellar surface with aid of neuronavigation, the cavernomas were safely resected.The video can be found here: https://youtu.be/fUDdaprg26Y.

Cognard type V dural fistulas represent a rare and unique entity, and present clinically with myelopathy. They are frequently located around the foramen magnum and are most commonly fed by dural branches of the vertebral and external carotid artery. Detection requires meticulous angiography to define the angioarchitecture of the fistula, which in turn defines the treatment modality. We present the case of a 63 yr old woman, after informed consent was obtained, with prolonged, severe and progressive lower extremity myelopathy for 6 yr, with T2-weighted signal changes in the thoracic spinal cord on magnetic resonance imaging (MRI). Cervical MRI was unremarkable. Following computed tomography (CT), angiography of the spinal canal that revealed tortuous and dilated veins on the thoracic spinal cord surface, catheter angiography was performed. This demonstrated a fistula in relation to a dural branch of left vertebral artery with a characteristic single draining vein coursing caudally to the thoracic level, with delayed outflow suggestive of venous hypertension. Given the fact that the dural feeder was tortuous and relatively small, thus, precluding distal microcatheter access, and with presence of a single accessible draining vein, microsurgical treatment was preferred. Following a midline suboccipital craniotomy in prone position, a limited vertical dural opening was performed. Careful microsurgical arachnoid dissection revealed the arterialized draining vein with the aid of Indocyanine Green angiography. The draining vein was clipped, coagulated, and disconnected. Postoperative recovery was uneventful and the patient is undergoing rehabilitation therapy. Follow-up angiography showed complete elimination of the fistula. Salient teaching points are narrated at conclusion.

We present the case of a 56-yr-old right-handed male, after informed consent was obtained, who presented with acute confusion and agitation, on the background of a remote history of an uncomplicated resection of a left parietal grade 2 glioma. Imaging revealed a large, acute right temporal intracerebral hemorrhage (ICH). Standard vascular workup for the cause of the ICH included catheter angiography. No direct cause of the hemorrhage was revealed; however, a high grade parasagittal dural arteriovenous fistula (DAVF) with cortical venous reflux was noted close to the prior craniotomy site. The venous reflux was towards the left hemisphere, but it was hypothesized that similar reflux on the right side may have been present and was not presently evident due to thrombosis. The DAVF was embolized by endovascular means, followed by evacuation of the hematoma. Follow-up angiogram 7 mo later revealed a high-flow, right superior temporal cortical arteriovenous malformation (AVM). The DAVF unfortunately had also progressed. Endovascular occlusion of both lesions was attempted but was not successful. Subsequently, microsurgical resection for both the vascular malformations was performed with careful pre- and intraoperative planning to obtain a successful clinical and angiographic result. In this video, we summarize diagnostic and therapeutic nuances that have broad implications for the workup of ICH and the strategic management of a unique scenario involving a brain AVM and high-grade cranial dural fistula in the same patient. Prior to each procedure, informed consent was obtained from the patient, which includes consent for publication.