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The effect of ventricular shunts on radiographic outcomes after evacuation of acute subdural hematomas (aSDHs) has not yet been established. We studied a series of patients who had undergone craniotomy for aSDH, exploring a possible relationship between the occurrence of a postoperative extra-axial collection (EAC) and the presence of a ventricular shunt.We reviewed all craniotomies for convexity aSDH performed between July 2015 and June 2020. The medical record review included perioperative coagulation studies, platelet counts, and antiplatelet and anticoagulation agent use. Univariate and multivariate analyses were conducted to identify the factors associated with postoperative EACs and reevacuation.A total of 58 patients had undergone craniotomy for aSDHs, including 9 with ventricular shunts. The median age was 67 years (interquartile range, 54-78 years), and 40% of the patients were women. Of the 58 patients, 16 were taking antiplatelet agents, and 6 were taking anticoagulation agents. Ten patients had developed perioperative thrombocytopenia (platelet count,100,000/μL). Twelve patients had perioperative coagulopathy (international normalized ratio, ≥1.5). A postoperative EAC10 mm occurred in 17 patients (29.3%). Eight patients (13.8%) had undergone reevacuation. The presence of a shunt and an increasing preoperative aSDH size were independently associated with an EAC10 mm (P = 0.013 and P = 0.003, respectively). Only the presence of a shunt predicted for the need for reevacuation (P = 0.001). The shunts were explanted (n = 3) or valves were adjusted (n = 3) in all but 3 cases.We found that a lack of brain reexpansion after aSDH evacuation worsens radiographic outcomes and was more common in patients with shunts. Increasing shunt valve resistance might help prevent the formation of large EACs after aSDH evacuation.

BackgroundPerihematomal edema (PHE) volume correlates with intracerebral hemorrhage (ICH) volume and is associated with functional outcome. Minimally invasive surgery (MIS) for ICH decreases clot burden and PHE. MIS may therefore alter the time course of PHE, mitigating a critical source of secondary injury.ObjectiveTo describe a new method for the quantitative measurement of cerebral edema surrounding the evacuated hematoma cavity, termed pericavity edema (PCE), and obtain details of its time course following MIS for ICH.MethodsThe study included 48 consecutive patients presenting with ICH who underwent MIS evacuation. Preoperative and postoperative CT scans were assessed by two independent raters. Hematoma, edema, cavity, and pneumocephalus volumes were calculated using semi-automatic, threshold-guided volume segmentation software (AnalyzePro). Follow-up CT scans at variable delayed time points were available for 36 patients and were used to describe the time course of PCE.ResultsMean preoperative, postoperative, and delayed PCE were 21.0 mL (SD 15.5), 18.6 mL (SD 11.4), and 18.4 mL (SD 15.5), respectively. The percentage of ICH evacuated correlated significantly with a decrease in postoperative PCE (r=−0.46, pConclusionsWe present a detailed and accurate method for measuring PCE volume with semi-automatic, threshold-guided segmentation software in the postoperative patient with ICH. Decrease in PCE after MIS evacuation correlated with evacuation percentage, and relative PCE remained stable after minimally invasive endoscopic ICH evacuation.

BACKGROUND Multiple surgical techniques to perform minimally invasive intracerebral hemorrhage (ICH) evacuation are currently under investigation. The use of an adjunctive aspiration device permits controlled suction through an endoscope, minimizing collateral damage from the access tract. As with increased experience with any new procedure, performance of endoscopic minimally invasive ICH evacuation requires development of a unique set of operative tenets and techniques. OBJECTIVE To describe operative nuances of endoscopic minimally invasive ICH evacuation developed at a single center over an experience of 80 procedures. METHODS Endoscopic minimally invasive ICH evacuation was performed on 79 consecutive eligible patients who presented a single Health System between March 2016 and May 2018. We summarize 4 core operative tenets and 4 main techniques used in 80 procedures. RESULTS A total of 80 endoscopic minimally invasive ICH evacuations were performed utilizing the described surgical techniques. The average preoperative and postoperative volumes were 49.5 mL (standard deviation [SD] 31.1 mL, interquartile range [IQR] 30.2) and 5.4 mL (SD 9.6, mL IQR 5.1), respectively, with an average evacuation rate of 88.7%. All cause 30-d mortality was 8.9%. CONCLUSION As experience builds with endoscopic minimally invasive ICH evacuation, academic discussion of specific surgical techniques will be critical to maximizing its safety and efficacy.

Intracerebral hemorrhage (ICH) is a subtype of stroke with high mortality and poor functional outcomes, largely because there are no evidence-based treatment options for this devastating disease process. In the past decade, a number of minimally invasive surgeries have emerged to address this issue, one of which is endoscopic evacuation. Stereotactic ICH Underwater Blood Aspiration (SCUBA) is a novel endoscopic evacuation technique performed in a fluid-filled cavity using an aspiration system to provide an additional degree of freedom during the procedure. The SCUBA procedure utilizes a suction device, endoscope, and sheath and is divided into two phases. The first phase involves maximal aspiration and minimal irrigation to decrease clot burden. The second phase involves increasing irrigation for visibility, decreasing aspiration strength for targeted aspiration without disturbing the cavity wall, and cauterizing any bleeding vessels. Using the endoscope and aspiration wand, this technique aims to maximize hematoma evacuation while minimizing collateral damage to the surrounding brain. Advantages of the SCUBA technique include the use of a low-profile endoscopic sheath minimizing brain disruption and improved visualization with a fluid-filled cavity rather than an air-filled one.

BACKGROUND Ventriculostomy-related infection (VRI) is a feared complication of external ventricular drain (EVD) placement. Although many contributing factors to VRI have been examined, little is known whether there is an association between ventriculostomy-related catheter tract hemorrhage (VCTH) and VRI. OBJECTIVE To evaluate risk factors for VRI and assess possible correlations with VCTH. METHODS We performed a retrospective analysis of patients with EVD placement in a neurocritical care unit between 2011 and 2015. VRI was defined as clinical signs of infection with a positive cerebrospinal fluid gram stain and isolation of cerebrospinal fluid culture. VCTH was diagnosed by computed tomography immediately after EVD insertion. RESULTS A total of 247 patients with EVD were identified during the 5-yr study period. An association between VCTH and gram-negative VRI was identified (P = .02). Ten percent (25 of 247 patients) developed a VRI, and 7% (18 of 247 patients) had a VCTH. Of the 25 patients with VRI, 20% (n = 5) had a VCTH, compared to 6% (n = 13) of 222 patients who had an EVD placed but did not develop VRI. There were no significant differences in demographic and clinical factors except for multiple EVD insertions (P

Background Intracerebral hemorrhage (ICH) is the most devastating form of stroke, with thalamic hemorrhages carrying the worst outcomes. Minimally invasive (MIS) endoscopic ICH evacuation is a promising new therapy for the condition. However, it remains unclear whether therapy success is location dependent. Here we present long-term functional outcomes after MIS evacuation of spontaneous thalamic hemorrhages. Methods Patients presenting to a single urban health system with spontaneous ICH were triaged to a central hospital for management of ICH. Operative criteria for MIS evacuation included hemorrhage volume ≥15 mL, age ≥18, National Institutes of Health Stroke Scale ≥6, and baseline modified Rankin Score (mRS) ≤3. Demographic, radiographic, and clinical data were collected prospectively, and descriptive statistics were performed retrospectively. Functional outcomes were assessed using 6-month mRS scores. Results Endoscopic ICH evacuation was performed on 21 patients. Eleven patients had hemorrhage confined to the thalamus, whereas 10 patients had hemorrhages in the thalamus and surrounding structures. Eighteen patients (85.7%) had intraventricular extension. The average preoperative volume was 39.8 mL (standard deviation [SD]: 31.5 mL) and postoperative volume was 3.8 mL (SD: 6.1 mL), resulting in an average evacuation rate of 91.4% (SD: 11.1%). One month after hemorrhage, 2 patients (9.5%) had expired and all other patients remained functionally dependent (90.5%). At 6-month follow-up, 4 patients (19.0%) had improved to a favorable outcome (mRS ≤ 3). Conclusion Among patients with ICH undergoing medical management, those with thalamic hemorrhages have especially poor outcomes. This study suggests that MIS evacuation can be safely performed in a thalamic population. It also presents long-term functional outcomes that can aid in planning randomization schemes or subgroup analyses in future MIS evacuation clinical trials.

To investigate potential health care discrepancies in patients with ruptured cerebral aneurysms undergoing microsurgical intervention.We retrospectively reviewed patients with ruptured intracranial aneurysms treated at our tertiary referral university hospital (UH) and safety net county hospital (CH) from 2010 to 2015. We identified 73 UH patients and 58 CH patients.UH patients had shorter time duration between rupture and intervention (P0.001) and higher rates of intubation on admission (P = 0.01). Verapamil was more frequently used for clinical vasospasm in UH patients, at 0.13 (95% confidence interval [CI], 0.09-0.18) treatments per patient per day versus 0.077 (95% CI, 0.047-0.12) treatments per patient per day in CH patients, though there was no difference in delayed cerebral ischemia (P = 0.15). The majority of the CH cohort was uninsured (26.3%; UH 0%) or had Medicaid (59.7%; UH 35.2%) (P0.001). The UH had more dispositions to home or rehabilitation centers than the CH (82% vs. 67.3%; P = 0.04). After adjusting for disease severity, hospital stay, and insurance status, CH patients were 3.73 (95% CI, 1.25-12.14) times more likely to be discharged with a poor modified Rankin Scale score and 3.08 (95% CI, 1.04-9.61) times more likely to be discharged with a poor Glasgow Outcome Scale score compared with UH patients (P = 0.02 and P = 0.04, respectively).Limited resource availability in a safety net hospital system could be a major driving force behind the health care discrepancy identified in our ruptured cerebral aneurysm population. Reallocation of resources to supplement advanced inpatient acute care technologies and, more importantly, post-acute care environments can narrow the outcomes gap.

BackgroundEndoscopic intracerebral hemorrhage (ICH) evacuation techniques have gained interest as a potential therapeutic option. However, the instrumentation and techniques employed are still being refined to optimize hemostasis and evacuation efficiency.ObjectiveWe describe the application of a specific endoscopic technique in the treatment of ICH called the Stereotactic Intracerebral Hemorrhage Underwater Blood Aspiration (SCUBA) technique. It differs from previously described minimally invasive ICH interventions in that it combines two separate neuroendoscopic strategies in two phases, the first under dry-field conditions and the second using a wet-field strategy.MethodsAll patients who underwent endoscopic ICH evacuation with the SCUBA technique from December 2015 to September 2017 were included.ResultsThe SCUBA technique was performed in 47 patients. The average evacuation percentage was 88.2% (SD 20.8). Active bleeding identified to derive from a specific source was observed in 23 (48.9%) cases. Active bleeding was addressed with irrigation alone in five cases (10.6%) and required electrocautery in 18 cases (38.3%). Intraoperative bleeding occurred in 3 patients (6.4%) and postoperative bleeding occurred in a single case (2.1%).ConclusionsThe SCUBA technique provides surgeons with a defined strategy for true endoscopic hematoma evacuation. In particular, the fluid-filled cavity in SCUBA Phase 2 has the potential to provide several advantages over the traditional air-filled strategy, including clear identification and cauterization of bleeding vessels and visualization of residual clot burden. Further investigation is necessary to compare this technique to others that are currently used.

Currently, there is no device capable of detecting acute ischemic stroke (AIS) secondary to emergent large vessel occlusion (ELVO) in the pre-hospital setting. The inability to reliably identify patients that would benefit from primary treatment with endovascular thrombectomy remains an important limitation to optimizing emergency medical services (EMS) triage models and time-to-treatment. Several clinical grading scales that rely solely on clinical examination have been proposed and have demonstrated only moderate predictive ability for ELVO. Consequently, a technology capable of detecting ELVO in the pre-hospital setting would be of great benefit. An analogous scenario existed decades ago, in which pre-hospital detection of acute myocardial infarction (AMI) was unreliable until the emergence of the 12-lead ECG and its adoption by EMS providers. This review details the implementation of pre-hospital ECG (PHECG) for the detection of AMI and explores how early experience with PHECG may be applied to ELVO detection devices, once they become available.

BACKGROUND The use of intraoperative navigation during microscope cases can be limited when attention needs to be divided between the operative field and the navigation screens. Heads-up display (HUD), also referred to as augmented reality, permits visualization of navigation information during surgery workflow. OBJECTIVE To detail our initial experience with HUD. METHODS We retrospectively reviewed patients who underwent HUD-assisted surgery from April 2016 through April 2017. All lesions were assessed for accuracy and those from the latter half of the study were assessed for utility. RESULTS Seventy-nine patients with 84 pathologies were included. Pathologies included aneurysms (14), arteriovenous malformations (6), cavernous malformations (5), intracranial stenosis (3), meningiomas (27), metastasis (4), craniopharygniomas (4), gliomas (4), schwannomas (3), epidermoid/dermoids (3), pituitary adenomas (2) hemangioblastoma (2), choroid plexus papilloma (1), lymphoma (1), osteoblastoma (1), clival chordoma (1), cerebrospinal fluid leak (1), abscess (1), and a cerebellopontine angle Teflon granuloma (1). Fifty-nine lesions were deep and 25 were superficial. Structures identified included the lesion (81), vessels (48), and nerves/brain tissue (31). Accuracy was deemed excellent (71.4%), good (20.2%), or poor (8.3%). Deep lesions were less likely to have excellent accuracy (P = .029). HUD was used during bed/head positioning (50.0%), skin incision (17.3%), craniotomy (23.1%), dural opening (26.9%), corticectomy (13.5%), arachnoid opening (36.5%), and intracranial drilling (13.5%). HUD was deactivated at some point during the surgery in 59.6% of cases. There were no complications related to HUD use. CONCLUSION HUD can be safely used for a wide variety of vascular and oncologic intracranial pathologies and can be utilized during multiple stages of surgery.

Background: Intracerebral hemorrhage (ICH) is a devastating disease with the worst morbidity and mortality of all the stroke subtypes. A predictor of hematoma expansion and poor functional outcome is the spot sign, a small enhancing focus within the hematoma that can be visualized on computed tomography angiography (CTA). A number of minimally invasive surgical (MIS) techniques have emerged to treat ICH, including MIS endoscopic ICH evacuation. However, there is limited literature correlating intraoperative bleeding with the location of the spot sign. The goal of this study is to determine if intraoperative bleeding at the location of a spot sign could be regularly detected and treated. Methods: A retrospective analysis on prospectively collected data was performed on ICH patients who received MIS endoscopic evacuation from December 2015 to June 2018. Patients qualified for MIS evacuation with hematoma volume ≥15cc, National Institute of Health Stroke Scale ≥6, Glasgow Coma Scale (GCS) ≥4, and baseline modified Rankin Score ≤ 2. Results: Of the 100 ICH patients who received endoscopic evacuation, 15 had a spot sign. The average age of these patients was 62.5 (SD: 16.7) and 14 (93%) were male. The average pre-operative, post-operative volume, and evacuation rate was 62.5 mL (SD: 31.0), 10.4 mL (SD: 15.6), and 81% (SD 33.7%) respectively. Intraoperative bleeding was reported in 9 (60%) cases, treated with irrigation in 2 (22%) cases and irrigation with cautery in 7 (78%) cases. Postoperative rebleeding within 24 hours occurred in 2 (13%) patients. 7 out of the 15 (47%) patients who had a spot sign also had a bleeding vessel identified at the same location as the spot sign. The average 30-day mRS was 3.6 (SD: 1.3). Conclusion: MIS endoscopic ICH evacuation reveals a bleeding vessel in spot sign patients in approximately 50% of cases. Evacuation of these hematomas carries a higher risk of encountering a bleeding vessel during the procedure but in all cases bleeding was effectively managed. Although evacuation of spot sign patients may mitigate the risk of hematoma expansion, it also carries a higher risk of post-operative rebleeding in this small patient cohort. Future studies will be necessary to determine the impact of this procedure on long-term functional outcomes.

Background Minimally invasive intracerebral hemorrhage (ICH) evacuation has gained popularity with success in early-phase clinical trials. This procedure, however, is performed in very different ways around the world. Objective To provide a technical description of these strategies that facilitates comparison and aids decisions in which surgery to perform, and to inform further improvements in minimally invasive ICH evacuation. Methods Major authors of clinical trials evaluating each of the main techniques were contacted and asked to supply a case example and technical description of their respective surgeries. Results Five major techniques are presented including stereotactic thrombolysis, craniopuncture, endoscopic, endoscope-assisted, and endoport-mediated. Techniques differ in numerous ways including the size of the cranial access, the size of the access corridor through the brain to the hematoma, and the evacuation strategy. Regarding cranial access, a burr hole is created in stereotactic thrombolysis and craniopuncture, a small craniectomy in endoscopic, and a small craniotomy in the other 2. Access corridors through the parenchyma range from 3 mm in craniopuncture to 13.5 mm in the endoport-mediated evacuation. Regarding evacuation strategies, stereotactic thrombolysis and craniopuncture rely on passive drainage from a catheter placed during surgery that remains in place for multiple days, while the other 3 techniques rely on active evacuation with suction and bipolar cautery. Conclusion Future comparative clinical trials may identify the advantageous components of each strategy and contribute to improved outcomes in this patient population.

Recent success in preliminary clinical studies evaluating various forms of minimally invasive surgery for spontaneous intracerebral hemorrhage (ICH) has renewed interest in the surgical treatment of this disease process. In December of 2016, phase 2 of the Minimally Invasive Surgery Plus Rt-PA for ICH Evacuation (MISTIE) study demonstrated that this form of stereotactic thrombolysis safely reduces clot burden and may improve functional outcome 6 months after injury. A smaller arm of this study, the Intraoperative Stereotactic Computer Tomography-Guided Endoscopic Surgery (ICES) study, also demonstrated feasibility and good functional outcome for endoscopic minimally invasive evacuation. Early-phase clinical studies evaluating various forms of minimally invasive surgery for intracerebral hemorrhage evacuation have shown safety and feasibility with a preliminary signal towards improved functional long-term outcome. Results from phase 3 studies addressing various minimally invasive techniques are imminent and will shape how intracerebral hemorrhage is treated.

Endovascular thrombectomy (EVT) is now the standard of care for eligible patients with acute ischemic stroke (AIS) secondary to emergent large vessel occlusion (ELVO). However, there remains uncertainty in how hospital systems can most efficiently route patients with suspected ELVO for EVT treatment. Given the relative geographic distribution of centers with and without endovascular capabilities, the value of prehospital triage directly to centers with the ability to provide EVT remains debated. While there are no randomized trial data available to date, there is substantial evidence in the literature that may offer guidance on the subject. In this review we examine the available data in the context of improving the existing AIS triage systems and discuss how prehospital triage directly to endovascular-capable centers may confer clinical benefits for patients with suspected ELVO.

Introduction: Perihematomal edema (PHE) impacts outcome in spontaneous intracerebral hemorrhage (ICH) and has been well defined. As minimally invasive evacuation methods are formally evaluated, the degree of edema following evacuation may differ from PHE in measurement and time course characteristics. Here we define pericavity edema (PCE) as a new entity and formally evaluate its measurement with a semi-automated threshold-guided technique. Methods: Patients (n=46) with a primary supratentorial ICH who underwent endoscopic evacuation were included in this study. AnalyzePro software was used to perform semi-automated threshold-guided volume assessment on pre and post evacuation noncontrast head CTs of the hematoma, PHE, the cavity, PCE, and pneumocephalus if present. Two raters analyzed each subject, the first twice, and intraclass correlation coefficient (ICC) values were determined to assess the inter-rater reliability. Statistical analysis was performed on the mean results to determine the change in hematoma volume, edema, cavity size, and degree of pneumocephalus. Results: ICC values for all variables were greater than 0.75, indicating good to excellent reliability. The median preoperative PHE was 18.21 cm3, while the postoperative edema was 16.2cm3. There was a mean 78.9% decrease in hematoma and a mean 76.4% increase in edema. In patients with a cavity present, the median size was 10.4cm3. Conclusions: In conclusion, PCE was successfully measured using AnalyzePro based on ICC. A mean increase in edema was shown following endoscopic evacuation, similar previous research revealing an increase in edema volume growth immediately following ICH. Further research will aim to define the time course of edema volume change following endoscopic evacuation.

OBJECTIVEPatients who have experienced subarachnoid hemorrhage (SAH) often receive care in the setting of the ICU. However, SAH patients may not all require extended ICU admission. The authors established a protocol on January 1, 2015, to transfer select, low-risk patients to a step-down unit (SDU) to streamline care for SAH patients. This study describes the results of the implemented protocol.METHODSIn this retrospective chart review, patients presenting with SAH between January 2011 and September 2016 were reviewed for inclusion. The control group consisted of patients admitted prior to establishment of the SDU transfer protocol, while the intervention group consisted of patients admitted afterward.RESULTSOf the patients in the intervention group, 79.2% (57/72) were transferred to the SDU during their admission. Of these transferred patients, 29.8% (17/57) required return to the neurosurgical ICU (NSICU). There were no instances of morbidity or mortality directly related to care in the SDU. Patients in the intervention group had a mean reduced NSICU length of stay, by 1.95 days, which trended toward significance, and a longer average hospitalization, by 2.7 days, which also trended toward significance. In-hospital mortality and 90-day readmission rate were not statistically different between the groups. In addition, early transfer timing prior to 7 days was associated with neither a higher return rate to the NSICU nor higher 90-day readmission rate.CONCLUSIONSIn this retrospective study, the authors demonstrated that the transfer protocol was safe, feasible, and effective in reducing the ICU length of stay and was independent of transfer timing. Confirmation of these results is needed in a large, multicenter study.

Aneurysmal subarachnoid hemorrhage (aSAH) and spontaneous intracranial hemorrhage (ICH) are frequently associated with epileptic complications. The use of anti-epileptic drugs (AEDs) for seizure prophylaxis, however, is controversial. In patients with aSAH, nonconvulsive status epilepticus has been associated with poor outcome. Effect of other forms of less severe epileptiform activity on clinical outcome remains unclear. Evidence on efficacy of AEDs in reducing seizure incidence is also mixed. However, increasing number of studies suggest that AEDs may have significant adverse effects on outcome, especially with phenytoin. Similarly, in patients with ICH, the impact of seizures that do not progress to status epilepticus on clinical outcome is controversial, and whether prophylactic AED use has independent effects on outcome remains ambiguous. Currently, there are no large scale randomized control trials investigating the efficacy and safety of AED prophylaxis in patients with hemorrhagic stroke. There are also no trials comparing the efficacy and safety of the different AEDs. Survey based studies have found a wide range of prescribing patterns across treatment centers and clinicians for seizure prophylaxis in patients with hemorrhagic stroke. The lack of clear guidelines and recommendations also highlights the paucity of good quality evidence in this area. In conclusion, a well-designed randomized, double blinded, and appropriately powered trial is needed to evaluate the incidence as well as clinical outcomes in patients with aSAH and ICH who received AED prophylaxis versus controls. The results will be extremely valuable in providing evidence to establish management guidelines for patients with hemorrhagic stroke.

Traumatic brain injury (TBI) is an important public health concern plagued by high rates of mortality and significant long-term disability in many survivors. Post-traumatic seizures (PTS) are not uncommon following TBI, both in the early (within 7 days post-injury) and late (after 7 days post-injury) period. Due to the potential of PTS to exacerbate secondary injury following TBI and the possibility of developing post-traumatic epilepsy (PTE), the medical community has explored preventative treatment strategies. Prophylactic antiepileptic drug (AED) administration has been proposed as a measure to reduce the incidence of PTS and the ultimate development of PTE in TBI patients. In this topical review, we discuss the pathophysiologic mechanisms of early and late PTS and the development of PTE following TBI, the pharmacodynamic and pharmacokinetic properties of AEDs commonly used to prevent post-traumatic seizures, and summarize the available clinical evidence for employing AEDs for seizure prophylaxis after TBI.

Endovascular thrombectomy has achieved a dramatical shift in our management strategies for ischemic stroke. With the benefits of increased reperfusion rates and improved outcomes, endovascular thrombectomy represents a significant improvement to the available management approaches. The cornerstone of this technique resides in its ability to achieve rapid recanalization of occluded vessels by direct removal of the occluding thrombus. Because of its endovascular nature, several complications can accompany the procedure. The most common associated complications include intracranial hemorrhage, vasospasm, and distal embolization. Other procedure-related complications accompany the endovascular approach and thus been recognized more recently, including arterial dissection and inadvertent thrombectomy device detachment. The severity can range widely, and the clinician must be familiar with these complications and the available management options when performing the endovascular thrombectomy procedure. This chapter will review the common complications, familiarize the reader with avoidance techniques, and discuss the current management options.

Endovascular thrombectomy device improvements in recent years have served a pivotal role in improving the success and safety of the thrombectomy procedure. As the intervention gains widespread use, developers have focused on maximizing the reperfusion rates and reducing procedural complications associated with these devices. This has led to a boom in device development. This review will cover novel and emerging technologies developed for endovascular thrombectomy.

A 59-year-old woman with a 30-year history of essential tremor refractory to medical therapy underwent staged deep brain stimulation of the ventralis intermedius nucleus of the thalamus (VIM). Left-sided lead placement was performed first. Once in the operating room, microelectrode recording (MER) was performed to confirm the appropriate trajectory and identify the VIM border with the ventralis caudalis nucleus. MER was repeated after repositioning 2 mm anteriorly to reduce the likelihood of stimulation-induced paresthesias. Physical examination prior to permanent lead placement demonstrated micro-lesion effect, suggesting optimal trajectory. After implantation of the permanent lead, physical examination showed excellent results.The video can be found here: https://youtu.be/nn3KRdmRCZ4.

Advances in stereotactic navigation technology have helped to improve the ease, reliability, and workflow of neurosurgical intraoperative navigation. These advances have also allowed novel, minimally invasive neurosurgical techniques to emerge. Minimally invasive techniques for intracerebral hemorrhage (ICH) evacuation, including endoscopic evacuation and passive catheter drainage, are notable examples, and as these gain support in the literature and their use expands, stereotactic navigation will take on an increasingly important and central role. Each neurosurgical navigation system has unique characteristics. Operators may find that certain aspects are more important than others, depending on the environment in which the evacuation is performed and operator preferences. This review will describe the characteristics of three popular stereotactic neuronavigation systems and compare their advantages and disadvantages as they relate to minimally invasive ICH evacuation.

Operators commonly encounter difficulty maneuvering a microcatheter beyond the distal lip of wide neck aneurysms and aneurysms in challenging locations. Few techniques have been described to guide operators in these particular situations. In this case report of a 56-year-old woman with a 16 mm ophthalmic artery aneurysm, the microcatheter continually snagged the distal aneurysm lip, preventing delivery of a flow diverter into the distal parent vessel. In troubleshooting this obstacle, a second microguidewire was introduced alongside the microcatheter and was used to cover the distal lip of the aneurysm to prevent further snagging. The second guidewire successfully deflected the microcatheter into the distal vessel, a technique that we have aptly dubbed the ‘bumper technique’.

Meningioma consistency is a critical factor that influences preoperative planning for surgical resection. Recent studies have investigated the utility of preoperative magnetic resonance elastography (MRE) in predicting meningioma consistency. However, it is unclear whether existing methods are optimal for application to clinical practice. The results and conclusions of these studies are limited by their imaging acquisition methods, such as the use of a single MRE frequency and the use of shear modulus as the final measurement variable, rather than its storage and loss modulus components. In addition, existing studies do not account for the effects of cranial anatomy, which have been shown to significantly distort the MRE signal. Given the interaction of meningiomas with these anatomic structures and the lack of supporting evidence with more accurate imaging parameters, MRE may not yet be reliable for use in clinical practice.

Neurosurgeons performing intracerebral hemorrhage evacuation procedures have limited options for monitoring hematoma evacuation and assessing residual hematoma burden intraoperatively. Here, we report the successful neuroendoscopic adaptation of intravascular ultrasound, referred to here as intracavitary ultrasound (ICARUS), in two patients. Pre-evacuation ICARUS demonstrated dense hematomas in both patients. Post-evacuation ICARUS in patient 1 demonstrated significant reduction in clot burden and two focal hyperechoic regions consistent with pockets of hematoma not previously seen with the endoscope or burr hole ultrasound. These areas were directly targeted and resected with the endoscope and suction device. Post-evacuation ICARUS in patient 2 showed significant reduction of hematoma volume without indication of residual blood. ICARUS findings were confirmed on intraoperative DynaCT and postoperative CT 24 hours later. ICARUS is feasibly performed in a hematoma cavity both before and after hematoma aspiration. ICARUS may provide additional information to the operating surgeon and assist in maximizing hematoma removal.

Neurosurgeons performing intracerebral hemorrhage evacuation procedures have limited options for monitoring hematoma evacuation and assessing residual hematoma burden intraoperatively. Here, we report the successful neuroendoscopic adaptation of intravascular ultrasound, referred to here as intracavitary ultrasound (ICARUS), in two patients. Pre-evacuation ICARUS demonstrated dense hematomas in both patients. Post-evacuation ICARUS in patient 1 demonstrated significant reduction in clot burden and two focal hyperechoic regions consistent with pockets of hematoma not previously seen with the endoscope or burr hole ultrasound. These areas were directly targeted and resected with the endoscope and suction device. Post-evacuation ICARUS in patient 2 showed significant reduction of hematoma volume without indication of residual blood. ICARUS findings were confirmed on intraoperative DynaCT and postoperative CT 24 hours later. ICARUS is feasibly performed in a hematoma cavity both before and after hematoma aspiration. ICARUS may provide additional information to the operating surgeon and assist in maximizing hematoma removal.

Operators commonly encounter difficulty maneuvering a microcatheter beyond the distal lip of wide neck aneurysms and aneurysms in challenging locations. Few techniques have been described to guide operators in these particular situations. In this case report of a 56-year-old woman with a 16 mm ophthalmic artery aneurysm, the microcatheter continually snagged the distal aneurysm lip, preventing delivery of a flow diverter into the distal parent vessel. In troubleshooting this obstacle, a second microguidewire was introduced alongside the microcatheter and was used to cover the distal lip of the aneurysm to prevent further snagging. The second guidewire successfully deflected the microcatheter into the distal vessel, a technique that we have aptly dubbed the ‘bumper technique’.

Background The caudal zona incerta (cZI) is an increasingly popular deep brain stimulation (DBS) target for the treatment of tremor-predominant disease. The dentatorubrothalamic tract (DRTT) is a white matter fiber bundle that traverses the cZI and can be identified using diffusion-weighted magnetic resonance imaging fiber tractography to ascertain its precise course. In this report, we compare 2 patient cases of cZI DBS, a responder and a nonresponder. Case Description Patient 1 (responder) is a 65-year-old man with medically refractory Parkinson disease who underwent bilateral DBS lead placement in the cZI. Postoperatively he demonstrated >90% reduction in baseline tremor and was not limited by stimulation side effects. Postoperative imaging showed correct lead placement in the cZI. Tractography revealed a DRTT within the field of stimulation, bilaterally. Patient 2 (nonresponder) is a 61-year-old man with medically refractory Parkinson disease who also underwent bilateral DBS lead placement in the cZI. He initially demonstrated >90% reduction in baseline tremor but developed disabling dystonia of his left leg and significant slurring of his speech in the months after surgery. Postoperative imaging showed bilateral lead placement in the cZI. Right-sided electrode revision was recommended and resulted in relief of tremor and reduced dystonic side effects. Tractography analysis of the original leads revealed a DRTT with an atypical anterior trajectory and a location outside the field of stimulation. Tractography analysis of the revised lead showed a DRTT within the field of stimulation. Conclusions Preoperative diffusion-weighted magnetic resonance imaging fiber tractography imaging of the DRTT has the potential to improve and individualize DBS planning.