Alexander G. Chartrain

Pre-hospital detection of acute ischemic stroke secondary to emergent large vessel occlusion: lessons learned from electrocardiogram and acute myocardial infarction

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.

Novel and emerging technologies for endovascular thrombectomy

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.

Navigation-Linked Heads-Up Display in Intracranial Surgery: Early Experience

Abstract 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.

The Stereotactic Intracerebral Hemorrhage Underwater Blood Aspiration (SCUBA) technique for minimally invasive endoscopic intracerebral hemorrhage evacuation

Background Endoscopic 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. Objective We 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. Methods All patients who underwent endoscopic ICH evacuation with the SCUBA technique from December 2015 to September 2017 were included. Results The 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%). Conclusions The 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.

A review and comparison of three neuronavigation systems for minimally invasive intracerebral hemorrhage evacuation

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.

Utility of preoperative meningioma consistency measurement with magnetic resonance elastography (MRE): a review

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.

A step-down unit transfer protocol for low-risk aneurysmal subarachnoid hemorrhage

OBJECTIVE Patients 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. METHODS In 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. RESULTS Of 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. CONCLUSIONS In 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.

Antiepileptics for Post-Traumatic Seizure Prophylaxis after Traumatic Brain Injury

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.

A review of acute ischemic stroke triage protocol evidence: a context for discussion

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.

Deep brain stimulation of the ventralis intermedius nucleus for the treatment of essential tremor

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 .