Clinical outcomes of first- and second-generation hydrogel coils compared with bare platinum coils: a systematic literature review.

Endovascular coiling has revolutionized intracranial aneurysm treatment; however, recurrence continues to represent a major limitation. The hydrogel coil was developed to increase packing density and improve neck healing and therefore decrease recurrence rates. In this paper, we review treatment outcomes of first- (1HCs) and second-generation (2HCs) hydrogel coils and compare them to those of bare platinum coils (BPC). A query of multiple databases was performed. Articles with at least 10 aneurysms treated with either 1HC or 2HC were selected for analysis. Collected data included aneurysm size, rupture status, initial occlusion, initial residual neck/aneurysm, packing density, mortality, morbidity, recurrence, and retreatment rates. The primary endpoint was recurrence at final follow-up. Secondary endpoints included residual neck and dome rates as well as procedure-related complications and functional dependence at final follow-up. Studies that compared 1HC to BPC showed significant lower recurrence (24% vs. 30.8%, p = 0.02) and higher packing density (58.5% vs. 24.1%, p < 0.001) in 1HC but no significant difference in initial occlusion rate (p = 0.08). Studies that compared 2HC to BPC showed lower recurrence (6.3% vs. 14.3%, p = 0.007) and retreatment rates (3.4% vs. 7.7%, p = 0.010) as well as higher packing density (36.4% vs. 29.2%, p = 0.002) in 2HC, with similar initial occlusion rate (p = 0.86). The rate of complications was not statistically different between HC (25.5%) and BPC (22.6%, p = 0.06). Based on our review, the 1HC and 2HC achieved higher packing density and lower recurrence rates compared to BPC. The safety profile was similar between both groups.

Microsurgical Treatment of Pineal Tumors: Anatomy and Techniques.

Pineal region tumors are challenging lesions in terms of surgical accessibility and removal.1 The complexity is compounded by the infrequency and heterogeneity of pineal neoplasms.2,3 In Video 1, we present the case of a 39-year-old woman who presented with progressive headaches and vision impairment. She underwent microsurgical resection for a pineal parenchymal tumor of intermediate differentiation. We discuss the rationale, risks, and benefits of treatment for this patient, as well as provide a detailed overview of the alternative approaches that may be considered. Additionally, we discuss the unique anatomic considerations for each approach and include a virtual reality-compatible 3-dimensional fly-through to highlight the relationship between the tumor and relevant venous anatomy. The patient tolerated the procedure well with excellent neurologic outcome, and her follow-up imaging showed no evidence of tumor recurrence.

Remote magnetic navigation enables precision telesurgery.

Medical devices actuated by external magnetic fields can create opportunities for clinical adoption of precision telesurgery.

Natural History of Cavernous Carotid Artery Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND: Cavernous carotid artery aneurysms (CCAAs) represent a common condition seen in clinical practice with significant practice variability. The aim of this systematic review and meta-analysis was to aggregate current evidence on the natural history of CCAAs. METHODS: MEDLINE/PubMed, EMBASE, and Cochrane Library were queried from inception until December 2023. The primary outcome of this study was CCAA-related mortality. The secondary outcomes of this study were aneurysm growth, intracranial ischemic and hemorrhagic events, improved non-cerebrovascular symptoms, and new or worsened non-cerebrovascular symptoms during follow-up. RESULTS: Ten studies met our inclusion criteria, involving 835 patients and 975 CCAAs. CCAA-related mortality had an incidence rate of 0.28 (95% confidence interval 0.12-0.64) per 100 person-years (PYs) of follow-up. The incidence rate of CCAA growth was 2.91 (1.05-8.07) per 100 PYs of follow-up. The incidence rate of CCAA-related intracranial ischemic events was 0.4 (0.16-1.01) per 100 PYs of follow-up. The incidence rate of CCAA-related intracranial hemorrhagic events was 0.54 (0.33-0.87) per 100 PYs of follow-up. The incidence rate of improved non-cerebrovascular symptoms was 2.51 (1.18-5.33) per 100 PYs of follow-up. The incidence rate of new or worsened non-cerebrovascular symptoms was 3.41 (2.03-5.73) per 100 PYs of follow-up. CONCLUSIONS: CCAAs are typically benign lesions with a low risk of rupture and life-threatening complications. CCAAs tend to follow an indolent course regarding non-cerebrovascular outcomes, and new or worsening symptoms are infrequent during the clinical course. However, spontaneous resolution of non-cerebrovascular symptoms and cranial nerve deficits at presentation is uncommon.

Cerebrospinal Venous Fistula Presenting with Cognitive Decline: Systematic Literature Review and Report of Two Cases.

OBJECTIVE: A cerebrospinal fluid (CSF) venous fistula (CVF) is an aberrant connection between the subarachnoid space and a vein resulting in CSF loss. The presentation and management of CVF with cognitive decline is incompletely understood. METHODS: A systematic review was completed following the PRISMA guidelines. Articles that included at least 1 case of imaging-confirmed CVF with details on patient treatment were included. A separate review of cases of patients with spontaneous intracranial hypotension (SIH) with frontotemporal dementia (FTD) or dementia symptoms was also completed. RESULTS: Ten CVF articles (69 patients; average age, 51.5 years) and 5 SIH with FTD or dementia articles (n = 41; average age, 55.9 years) were identified. Only 1 patients with CVF with cognitive abnormalities was identified. The most common symptom was headache in both reviews. Brain sag was identified in all patients, whereas CSF leak was identified in only 2 patients with SIH with FTD or dementia (4.9%). An epidural blood or fibrin glue patch was used in all patients with CVF and in 33 patients with SIH with FTD or dementia. Fifty-five patients with CVF (79.7%) and 27 patients with SIH with FTD or dementia (65.9%) had surgery. CONCLUSIONS: The 2 cases and literature reviews show the difficulty in diagnosis and treatment of CVF with cognitive decline. Novel imaging techniques should be used in patients with cognitive decline in whom a CSF leak is suspected. Transvenous embolization or surgery should be considered before patching for treatment of CVF-induced brain sag and resulting dementia.

Predictive Model Evaluating Risk of Hemorrhage in Intracranial Aneurysms: Analysis from Prospectively Collected HEAT Trial Database.

OBJECTIVE: We analyzed the data of patients enrolled in the Hydrogel Endovascular Aneurysm Treatment (HEAT) trial to develop and validate a model to predict the risk of aneurysmal hemorrhage. METHODS: Analysis included data from 600 patients enrolled for the HEAT trial and included single saccular aneurysms of 3-14 mm size. Baseline characteristics were compared between patients with ruptured and unruptured aneurysms. Regression analysis was performed in the training set to identify significant risk factors and was validated in the validation dataset. The complete dataset was used to formulate a scoring model in which positive and negative predictors were assigned 1 and -1 points, respectively. RESULTS: Data from 593 patients were analyzed in which 169 (28.5%) patients had ruptured aneurysms. The training (n = 297) and validation dataset (n = 296) had a comparable proportion of ruptured aneurysms (29.3% and 27.7%). Dome-to-neck ratio >2.5 (odds ratio [OR] 3.66), irregular shape (OR 3.79), daughter sac (OR 5.89), and anterior and posterior communicating artery locations (OR 3.32 and 3.56, respectively) had a higher rupture rate. Use of aspirin was associated with lower risk of hemorrhage (OR 0.16). The area under the curve from the receiver operating curve analysis was 0.88, 0.87, and 0.87 in the training, validation, and combined data set, respectively. The scoring model created a score of -1 to 2, yielding an of aneurysmal hemorrhage probability from 1.5% (score -1) to 70% (score 2). CONCLUSIONS: This prospective study identifies dome-to-neck ratio >2.5, irregular shape, presence of daughter sac, absence of aspirin use, and aneurysm location at anterior communicating and posterior communicating artery as factors associated with increased risk of hemorrhagic presentation in small- to medium-sized intracranial aneurysms. Our model provides an estimate of rupture risk based on the presence or absence of these factors.

Microsurgical Clipping of a Postcoiling, Residual or Recurrent, Ruptured Anterior Communicating Artery Aneurysm.

Endovascular treatment modalities for intracranial aneurysms have seen a significant increase in popularity since the initial advent of the Guglielmi detachable coils in the early nineties.1 The publication of the International Subarachnoid Aneurysm Trial (ISAT) in addition to significant improvement in catheter and coil technology further cemented the endovascular-first approach, specifically for ruptured aneurysms.2 However, the increase in aneurysm coiling also led to a heightened awareness of its shortcomings, namely a significantly greater rate of recurrence and need for retreatment.3 The Cerebral Aneurysm Rerupture After Treatment (CARAT) study revealed that even though the rate of rerupture is low with both microsurgical and endovascular treatment modalities, the rate of rerupture is greater with incomplete versus complete aneurysm occlusion.4 Previously coiled aneurysms can be challenging to treat. While in some cases further endovascular therapies can be performed, microsurgical clipping remains a compelling alternative, specifically for small recurrent or residual ruptured aneurysms. However, microsurgical clipping of previously coiled aneurysms presents its own set of unique challenges. The presence of coils in the aneurysms increases the complexity of clip reconstruction. In addition, coil extrusion, which is often misdiagnosed as coil compaction on diagnostic imaging and therefore underreported, can further increase the risk of microsurgical dissection. In this operative video, we present a case of a postcoiling, residual or recurrent, ruptured anterior communicating artery aneurysm successfully treated through microsurgical clipping. The patient consented to the procedure as shown in this operative video (Video 1) and gave informed written consent for use of her images in publication.

Microsurgical Technique for Resection of a Cerebellopontine Angle Epidermoid Tumor.

Epidermoid tumors are slow-growing, benign, congenital lesions.1 They commonly arise in the cerebellopontine angle, fourth ventricle, suprasellar region, or spinal cord.2 Symptoms may include hearing loss, facial pain, and headaches. The management options include observation or surgical resection. If the patient has symptoms, surgical resection is the treatment option of choice with the goal of gross total resection. In Video 1, we discuss the microsurgical technique for the resection of a right cerebellopontine angle epidermoid tumor. A 22-year-old male patient presented with chronic headache, decreased right-sided hearing, right facial pain, and right facial twitching. Magnetic resonance imaging revealed the characteristic finding of an epidermoid tumor, which appeared as isointense on T1 and hyperintense on T2 with diffusion-weighted imaging. The patient was taken to the operating room, and a retrosigmoid craniotomy was performed on the basis of the transverse and sigmoid sinuses. The tumor capsule was opened, and the tumor was decompressed by removing the internal components consisting of epithelial keratin and cholesterol crystals, allowing for a gross total resection to be achieved. The patient's postoperative computed tomography scan showed no residual tumor, and the patient was discharged on postoperative day 1 in stable condition.

Awake Resection of an Arteriovenous Malformation.

Arteriovenous malformations (AVMs) are a highly complex array of abnormal arteries and veins that directly fistulize without intervening capillary beds.1 As AVMs can differ in size, location, and morphology, specific clinical management is determined for each individual patient, in conjunction with their specific goals and needs.2 This Video demonstrates the resection of an AVM located in the language area of eloquent cortex of a 38-year-old opera singer. The patient presented to the emergency department with a new-onset seizure. Magnetic resonance imaging including task-based functional imaging demonstrated a left post temporal AVM with associated hemosiderin-stained white matter and language activation just posterior to the lesion. Awake microsurgical resection was recommended given her career as an opera singer and the high-risk location of the AVM in proximity to eloquent language cortex, with additional goals of preventing further risk of hemorrhage and reduction in the risk of epilepsy. The patient underwent a left temporoparietal craniotomy with direct electrical stimulation-based language mapping and monitoring along with microsurgical resection of the AVM with image guidance, confirmed with intraoperative indocyanine green angiography. Postoperative angiography demonstrated no residual AVM with preservation of normal arterial and venous anatomy. At follow-up, the patient was clinically intact, seizure free, and off all antiepileptic medications. At 3 months, she resumed her career as an opera singer. Awake resection with intraoperative functional mapping can be used for select small AVMs to avoid injury to functional tissue and allow more aggressive resection of potentially epileptogenic tissue.

Real-Time MRI-Guided Stereotactic Aspiration of Spontaneous Intracerebral Hematoma: A Preclinical Feasibility Study.

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.

A comparison of treating physician versus independent core lab assessments of post-aneurysm treatment imaging outcomes: an analysis of prospectively collected data from a randomized trial.

OBJECTIVE: Aneurysm occlusion has been used as surrogate marker of aneurysm treatment efficacy. Aneurysm occlusion scales are used to evaluate the outcome of endovascular aneurysm treatment and to monitor recurrence. These scales, however, require subjective interpretation of imaging data, which can reduce the utility and reliability of these scales and the validity of clinical studies regarding aneurysm occlusion rates. Use of a core lab with independent blinded reviewers has been implemented to enhance the validity of occlusion rate assessments in clinical trials. The degree of agreement between core labs and treating physicians has not been well studied with prospectively collected data. METHODS: In this study, the authors analyzed data from the Hydrogel Endovascular Aneurysm Treatment (HEAT) trial to assess the interrater agreement between the treating physician and the blinded core lab. The HEAT trial included 600 patients across 46 sites with intracranial aneurysms treated with coiling. The treating site and the core lab independently reviewed immediate postoperative and follow-up imaging (3-12 and 18-24 months, respectively) using the Raymond-Roy occlusion classification (RROC) scale, Meyer scale, and recanalization survey. A post hoc analysis was performed to calculate interrater reliability using Cohen's kappa. Further analysis was performed to assess whether degree of agreement varied on the basis of various factors, including scale used, timing of imaging, size of the aneurysm, imaging modality, location of the aneurysm, dome-to-neck ratio, and rupture status. RESULTS: Minimal interrater agreement was noted between the core lab reviewers and the treating physicians for assessing aneurysm occlusion using the RROC grading scale (k = 0.39, 95% CI 0.38-0.40) and Meyer scale (k = 0.23, 95% CI 0.14-0.38). The degree of agreement between groups was slightly better but still weak for assessing recanalization (k = 0.45, 95% CI 0.38-0.52). Factors that significantly improved degree of agreement were scales with fewer variables, greater time to follow-up, imaging modality (digital subtraction angiography), and wide-neck aneurysms. CONCLUSIONS: Assessment of aneurysm treatment outcome with commonly used aneurysm occlusion scales suffers from risk of poor interrater agreement. This supports the use of independent core labs for validation of outcome data to minimize reporting bias. Use of outcome tools with fewer point categories is likely to provide better interrater reliability. Therefore, the outcome assessment tools are ideal for clinical outcome assessment provided that they are sensitive enough to detect a clinically significant change.

Microsurgical Resection of Dorsal Pontine Cavernous Malformation: The Telovelar Approach Augmented by the Tonsillouvular Fissure Exposure: 2-Dimensional Operative Video.

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 FV1 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.

Optic Canal Decompression: Concepts and Techniques: 2-Dimensional Operative Video.

The optic canal (OC) is a bony channel that transmits the optic nerve (ON) and ophthalmic artery (OphA) as they course through the lesser wing of the sphenoid bone to the orbital apex. The OC is involved in a variety of intracranial and extracranial pathologies,1 and opening of the canal may be necessary in order to achieve adequate exposure, better disease control, and vision preservation.2 Depending on the location of the pathology and its relationship with the optic nerve, the OC may be decompressed through an open transcranial approach or an endoscopic endonasal approach.1,3 OC drilling can be tailored based on the location of the pathology and its extension. Anterior clinoid process and optic strut drilling can be added based on these factors as well.4,5 In this video, we demonstrate the steps of OC drilling in both transcranial microscopic and endoscopic endonasal approaches through a combination of animated illustrations and operative videos. We present 4 cases, including 2 transcranial microscopic and 2 endoscopic endonasal approaches,6 demonstrating OC decompression and its technical nuances. Each case was selected to represent the range of pathologies relevant to OC drilling to allow for a complete understanding of the techniques and concepts required for optimal treatment. An informed written consent has been obtained from each of the patients in this publication. Video © Mayo Foundation for Medical Education and Research. All rights reserved. Images at 1:03-1:10 © The Rhoton Collection. Images at 3:56-4:07 Reprinted from World Neurosurgery, vol 124, Caporlingua et al,3 Copyright 2019, with permission from Elsevier. Images at 9:02-9:48 reprinted from Bendok et al,6 by permission of the Congress of Neurological Surgeons.

Use of Temporary Rod and Intraoperative Neuroimaging for Correction of Adolescent Idiopathic Scoliosis: 2-Dimensional Operative Video.

Adolescent idiopathic scoliosis (AIS) is an abnormal lateral curvature of the spine that arises during the pubescent growth spurt. AIS mainly affects females in the age group of 10 to 16 yr, with a prevalence of about 1% to 3% in the at-risk population.1 Treatment options vary depending on disease presentation and severity. Mild curvature mainly requires periodic observation for disease progression, whereas more moderate curvature can necessitate bracing or corrective surgery.2 Here, we present the use of a temporary rod and neuroimaging for the correction of Lenke type 1 spinal curvature in an AIS patient. An inferior facetectomy is performed, and a Lenke probe is used for entry into the pedicle and vertebral body. The channel is sounded before and after tapping to check for adequate walls prior to insertion of the pedicle screw. The ARTIS pheno is brought into the field, which uses fluoroscopy to create a 3-dimensional (3D) representation of the instrumentation within the spine. A temporary rod is placed in the concavity, and a combination of corrective techniques, including a rod roll, apical translation, and reduction, is performed to bring up the concavity, derotate the spine, and translate the spine. The permanent rod is then placed in the convexity, and compression is performed to bring down the scapular prominence. The temporary rod is then removed, and a final rod is placed to complete the 3D correction. The patient consented to the procedure, and an informed written consent was obtained from the patient to use her photographs and video recordings for publication.

Microvascular Decompression Technique for Trigeminal Neuralgia Using a Vascular Clip.

Microvascular decompression (MVD) surgery is a well-established, effective treatment option for trigeminal neuralgia1 and hemifacial spasm.2 In 1967, Janetta et al3 introduced the concept of MVD surgery and pioneered the Janetta technique in which Teflon felt implants are placed between the trigeminal nerve and offending vessel. Though many cases are successfully managed with Teflon interposition, alternative techniques have been developed with the objective to alleviate vascular compression symptoms indefinitely, including transposition using biological glue,4 vascular clips,5,6 and a variety of "sling" techniques.7 In Video 1, we demonstrate a fenestrated clip transposition technique in the treatment of trigeminal neuralgia. We present the case of a 72-year-old female who presented with classic trigeminal neuralgia pain along the V2 and V3 distributions. Magnetic resonance imaging revealed evident compression of the trigeminal nerve by the superior cerebellar artery (SCA). A retrosigmoid craniotomy was performed, and the vascular loop of the SCA was visualized compressing the root entry zone with significant indentation of the trigeminal nerve. Wide arachnoid dissection along the SCA was carried out in order to mobilize the SCA away from the nerve. A small slit was created in the undersurface of the tentorium, and then the SCA loop was transposed to the tentorium using a fenestrated aneurysm clip. The postoperative course was uneventful, and the patient had complete resolution of her facial pain at 6-month follow-up. This method is likely an effective and durable method of decompression for trigeminal neuralgia.

Normalization of Peri-Arteriovenous Malformation Hemodynamics Prior to Direct Microsurgery: 2-Dimensional Operative Video.

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.

Microvascular Transposition Without Teflon: A Single Institution's 17-Year Experience Treating Trigeminal Neuralgia.

BACKGROUND: Trigeminal neuralgia (TN) refractory to medical management is often treated with microvascular decompression (MVD) involving the intracranial placement of Teflon. The placement of Teflon is an effective treatment, but does apply distributed pressure to the nerve and has been associated with pain recurrence. OBJECTIVE: To report the rate of postoperative pain recurrence in TN patients who underwent MVD surgery using a transposition technique with fibrin glue without Teflon. METHODS: Patients were eligible for our study if they were diagnosed with TN, did not have multiple sclerosis, and had an offending vessel that was identified and transposed with fibrin glue at our institution. All eligible patients were given a follow-up survey. We used a Kaplan-Meier (KM) model to estimate overall pain recurrence. RESULTS: A total of 102 patients met inclusion criteria, of which 85 (83%) responded to our survey. Overall, 76 (89.4%) participants responded as having no pain recurrence. Approximately 1-yr pain-free KM estimates were 94.1% (n = 83), 5-yr pain-free KM estimates were 94.1% (n = 53), and 10-yr pain-free KM estimates were 83.0% (n = 23). CONCLUSION: Treatment for TN with an MVD transposition technique using fibrin glue may avoid some cases of pain recurrence. The percentage of patients in our cohort who remained pain free at a maximum of 17 yr follow-up is on the high end of pain-free rates reported by MVD studies using Teflon. These results indicate that a transposition technique that emphasizes removing any compression near the trigeminal nerve root provides long-term pain-free rates for patients with TN.

The Utility of 5-Aminolevulinic Acid for Microsurgical Resection of Meningiomas.

Fluorescence-guided resection of brain tumors using 5-aminolevulinic acid (5-ALA) has been established for high-grade gliomas. Recently, its application for the resection of low grade tumors and benign lesions including meningioma has been suggested in the literature.1 Achieving a Simpson grade I resection in meningioma surgery is associated with a lower rate of recurrence.2,3 Although meningiomas are mostly benign and well-circumscribed lesions, they can be locally aggressive, invading brain parenchyma and other critical structures. In these cases, 5-ALA-guided resection may help maximize the extent of tumor resection and limit disruption of normal structures. In this video, we present 3 cases demonstrating the use of 5-ALA-induced fluorescence to alleviate 3 specific challenges in meningioma resection: 1) to aid visualization with a minimally invasive approach, 2) to distinguish recurrent tumor from scar tissue from prior treatments, and 3) to ensure that no viable tumor cells remain on the surface of a critical artery. The first patient is a 60-year-old woman who was found to have an incidental left sphenoid wing meningioma on magnetic resonance imaging. We elected for an extended lateral orbital craniotomy through a transpalpebral approach. The second patient is a 72-year-old man with recurrent left occipital parietal meningioma who underwent a parietal craniotomy. The third case was a 62-year-old woman with a foramen magnum meningioma encircling the left vertebral artery. These cases demonstrate the utility of 5-ALA in a variety of challenges associated with resection of meningiomas (Video 1).

Microvascular Decompression and Transposition of the 8th Cranial Nerve Using a Fenestrated Clip.

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).

Surgical Outcomes with Midline versus Lateral Approaches for Cranial Base Chordomas: A Systematic Review and Meta-Analysis.

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.