Mithun G. Sattur

Remote supratentorial extradural hematoma following posterior fossa surgery

IntroductionPosterior fossa tumors are associated frequently with hydrocephalus. Remote supratentorial hematoma after posterior fossa surgery is a rare but dreaded complication.DiscussionThese hematomas can be intraparenchymal or extradural. The possible causes include sudden decompression of ventricular pressure in the supratentorial compartment, rupture of cortical veins in the sitting position, coagulopathy, hemodynamic fluctuations during surgery, and position-related ischemia. We report a large bifrontal extradural hematoma following posterior fossa surgery for a vermian medulloblastoma.

Safety and Efficacy of the Sofia (6F) PLUS Distal Access Reperfusion Catheter in the Endovascular Treatment of Acute Ischemic Stroke

BACKGROUND Neuroendovascular intervention has become a key treatment option for acute ischemic stroke. The Sofia (6F) PLUS catheter was designed for neurovascular access for diagnostic or therapeutic interventions. OBJECTIVE To report the first series describing use of the Sofia PLUS intermediate/distal access reperfusion catheter in the treatment of acute ischemic stroke. METHODS In this retrospective study, 41 stroke cases were identified in which the catheter was utilized for thrombolysis/thrombectomy. Mean preprocedure National Institutes of Health Stroke Scale score was 16.5 ± 5.2 (range 4-29). Occluded vessels included the M1 segment, M2 segment, internal carotid artery terminus, cervical internal carotid artery, and basilar artery. RESULTS Successful positioning of the Sofia PLUS catheter near the occlusion site was achieved in 38 (92.7%) of 41 cases in which thrombectomy or thrombolysis was attempted using intraarterial tissue plasminogen activator, a direct aspiration first-pass technique, and/or stent retrieval. A postprocedure thrombolysis in cerebral infarction (TICI) score of 2b/3 was achieved in 37 of 41 cases. Of 15 cases where the Sofia PLUS was used for a direct aspiration first-pass technique, TICI 2b/3 was achieved in 11 (73.3%). In one case where intra-arterial tissue plasminogen activator was used as the only treatment modality, TICI 2a was achieved. No device-related or catheter-related complications were observed. The mean 7-d-postprocedure National Institutes of Health Stroke Scale score among the 39 survivors was 8.5 ± 7.3 (range 0-23). CONCLUSION Initial results with use of the Sofia (6F) PLUS for endovascular treatment of acute ischemic stroke have been encouraging. Experience with a larger series is warranted to further evaluate the safety and efficacy of this device and compare it with other reperfusion catheters.

Thinking from the Heart: Neurocristopathy, Aortic Abnormalities, and Intracranial Aneurysms.

he formation of intracranial aneurysms (IAs) has been intensively investigated due to its potential for devasT tating consequences. Numerous studies have documented the strong association between aneurysm pathophysiology and “traditional” atherosclerotic risk factors such as smoking, hypertension, and vessel wall inflammation. The presence of multiple aneurysms and familial occurrence, however, raises the valid question of the extent to which genetically determined factors contribute to the phenotype of an innate arteriopathy. Such an association between IAs and several monogenic or polygenic syndromes is well known.

Photoacoustic Imaging for Maximizing Glioma Resection

Increased extent of resection for both lowand high-grade gliomas has been shown to improve progression-free and overall survival. An extent of resection >98% or a contrast-enhancing residual tumor volume of <2 cm has been shown to significantly increase survival for patients with glioblastoma multiforme. Similarly, residual tumor volume of <15 cm improves survival for patients with low-grade gliomas. Current modalities used to maximize resection are 5-aminolevulinic acid (5-ALA) fluorescence and intraoperative magnetic resonance imaging (MRI). 5-ALA-fluorescence-guided resections have been shown to increase the rate of gross total resection and increase 6-month progression survival in high-grade gliomas but require the use of the 5-ALA dye, which can cause skin photosensitivity during and after surgery. The use of intraoperative MRI allows increased resection volumes comparable with those achieved using 5-ALA florescence but requires expensive infrastructure investments and is time consuming. Further modalities are certainly welcome toward realizing the goal of maximal tumor removal while minimizing additional time, cost, and procedure sequela. Photoacoustic imaging (PAI) is an experimental imaging modality that allows interrogation of matter at the molecular level. Derivatives of the technique include photoacoustic tomography (PAT) and multiphoton photoacoustic spectroscopy (MPS). These modalities use a laser to excite molecules (for instance, photon activation), which subsequently undergo characteristic nonradiative decay, producing ultrasonic waves dependent on the molecules excited. The key advantage of PAI over other imaging modalities is the ability to detect chemical species with cellular level accuracy. The technique has been used to localize brain activity in mice in vivo by measuring hemodynamic changes due to metabolic activity and is beginning to find clinical application in breast imaging. High-resolution vascular imaging in mice and humans using PAT has also been achieved. The potential of PAI to investigate brain tissue intraoperatively with cellular-level resolution could allow surgeons to detect low concentrations of malignant cells not visible via other modalities, resulting in more precise and extensive resections of gliomas, as well as differentiate between white and gray matter. Confocal microscopy in conjunction with dyes like 5-ALA is also capable of high-resolution imaging and identification of histologic features but requires contrast agents, whereas PAI does not. In a recent issue of Biomedical Optics, Dahal and Cullum investigated the ability of MPS to distinguish between healthy and malignant brain tissue in vitro. Twelve matched pairs of

Hypothermia not Supported as a Therapeutic Option for Traumatic Brain Injury in Recent Randomized Trial

Traumatic brain injury (TBI) is a leading cause of permanent disability in people younger than 40 years of age. An increase in intracranial pressure (ICP) during hospitalization for a TBI has been associated with poor long-term neurologic outcomes. On the basis of encouraging research, hypothermia has been embraced by some centers as an innovative way to treat high ICP. More recent trials, however, have hinted that therapeutic hypothermia might contribute to poor neurologic outcomes. In an attempt to define the role of hypothermia in TBI, the Eurotherm 3235 Trial collaborators conducted a randomized controlled trial, which was published October 7, 2015 in the New England Journal of Medicine. The inclusion criteria included patients with closed head injury who sustained an ICP >20 mm Hg for >5 minutes. For the purpose of creating a framework for study analysis, treatments for TBI were divided into stage 1, 2, and 3 therapies (Table 1). Eligible patients were randomized to an experimental arm, hypothermia (32 C 35 C) in addition to best management practice, and a control arm that consisted of best management practices alone. Statistical analysis was performed using ordinal logistic regression to compare the Extended Glasgow Outcome Scale scores between the hypothermia and control groups at 6 months. Only 25.7% of patients from the hypothermia group (49/191) had favorable outcomes at

Synthetic Replica for Training in Microsurgical Anastomosis: An Important Frontier in Neurosurgical Education

Medical education has evolved through the years, moving away from the Halstedian apprenticeship model. The medical governing bodies involved in medical graduate education have established a set of rulings and recommendations focused on improving patient safety and curbing resident fatigue including limiting work hours to 80 h a week. In addition to duty hour regulations, decreasing volumes and dilution of surgical cases among an increasing number of tertiary care centers have raised concern about the ability of residents to achieve appropriate levels of competency by the time of graduation. Therefore, simulation has seen an increased role in education in the last decade.

Complication Avoidance and Management Research

Complication avoidance is a major consideration with any surgical procedure, and evaluation of complications relies on clear definitions. However, defining what constitutes a complication can be difficult, as perspectives on errors of commission or omission often vary between providers and patients. Here, we present a concise analysis of complications related to neurovascular surgery (defined as any procedural care of patients with neurovascular diseases) and provide a framework for approaching research efforts. This is done by considering opportunities in disease screening and patient selection, perioperative morbidity reduction, and follow-up. In addition, the concept of complication avoidance through surgical simulation is briefly dealt with. This chapter is intended to serve as an initial reference point for the young neurovascular specialist for developing and elaborating on the concept of complication avoidance through various techniques of research.

New generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT): a study protocol for a multicenter randomized controlled trial

PurposeAneurysm 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.MethodsThe 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.ResultsPatient 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.ConclusionThe 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.

E-037 Computational modeling for the pre-treatment planning of flow diverting stents

Introduction Sizing flow diverters (FDs) can be challenging during cerebral aneurysm pre-treatment planning. FDs can differ from their labelled lengths by 30% after deployment because of changes in vessel curvature and diameter.1 Current FD sizing tools do not account for vessel shape or predict device apposition. We present a pilot study to evaluate the use of computational modelling for FD sizing. The modelling software is based on the finite element approach and has been shown to simulate FD deployments that closely match clinical deployments.2 Methods Twenty-four patient cases in three hospitals were selected for treatment with the pipeline embolization device. Twelve of the cases were pre-planned using the SurgicalPreView computational modeling software, while the remaining cases were conventionally planned. In the computationally modeled cases, each patient’s CT image data were uploaded to SurgicalPreView and re-constructed before treatment. The principal physician simulated deployment of 1–3 different FDs on the software and evaluated simulation results before treatment. After treatment, the physician filled out a questionnaire on the usefulness of the simulation results. Further, post-treatment image data for the 12 cases were used to compare simulated and clinical deployments. Results According to physician responses, computational modeling was useful for all cases and it improved confidence in device selection. In 58% of cases, simulation results changed the physician’s original device selection. In most cases, the physician selected a longer length device or a larger device diameter after evaluating simulation results. Limited effect was observed on operative time and the number of endovascular devices used. An example comparison between simulated and clinical deployments is shown in figure 1.Abstract E-037 Figure 1 Comparison between clinical and simulated FD deployments Conclusion Overall, the pilot study showed improvements in FD pre-treatment planning using computational modeling. Simulation results helped physicians predict the behavior of FDs in tortuous vessels and with maximizing apposition. Pretreatment planning may reduce costs by shortening operative time and reducing the number of devices used. Improvements to FD selection can potentially lead to better patient outcomes. References Fernandez H, Macho J, Andaluz J, Serra L, Larrabide I. Braided device foreshortening. presented at the Computer Assisted Radiology and Surgery, 2014. Babiker H, et al. Clinical validations of simulated neurovascular braided stent deployments. presented at the Frontiers in Medical Devices Conference – Innovations in Modeling and Simulation: Patient-Centered Healthcare, Washington, DC, 2016. Disclosures B. Chong: 4; C; Endovantage LLC. B. Bendok: None. C. Krishna: None. M. Sattur: None. B. Brown: None. R. Tawk: None. D. Miller: None. L. Rangel-Castilla: None. G. Lanzino: None.

Bioresorbable Intracranial Sensors: A New Frontier for Neurosurgeons

The management of brain, spinal cord, and peripheral nerve disorders and injury may benefit from more robust continuous monitoring. Implantation of biosensors is limited by the risk of infection and the need for a second procedure to extract the sensor. Bioresorbable sensors are electronic sensors that can run the required functional course in the body but eliminate via absorption over a reasonable period of time. If properly designed, bioresorbable sensors promise to overcome the limitations of current sensors and reduce the threshold for continuous monitoring.