Cerebral vasospasm following tumor resection: Illustrative cases and review of the literature.

BACKGROUND: Cerebral vasospasm (CV) after tumor resection is a rare event, although it is associated with poorer postoperative outcomes and increased morbidity and mortality. Given the potential for neurologic injury secondary to CV, there is a need for further understanding of this phenomenon. Therefore, the purpose of this study is to investigate the risk factors of CV following intracranial tumor resection. METHODS: A literature review was conducted identifying 61 studies (40 individual case reports, 14 case series, and 7 cohort studies) reporting 179 individual cases. Additionally, two illustrative cases were presented. RESULTS: Post-tumor resection CV was reported more often in males (58.0 %) than females (42.0 %), with an average age of onset of 47.3 years in males compared to 40.4 years in females. Of those specified, CV most commonly occurred in posterior fossa tumors (51.8 %), followed by the sellar/suprasellar region (36.6 %). The most common pathologies were schwannoma (31.8 %), pituitary adenoma (27.8 %), meningioma (15.2 %), and craniopharyngioma (9.9 %). Vasospasm most commonly occurred diffusely in the anterior circulation (60.2 %), with MCA and ACA involvement indicated in 72.7 % and 64.8 % of all cases, respectively. Symptomatically, CV most commonly presented with altered mental status (73.9 %) or weakness (60.9 %), specifically hemiparesis (37.0 %) or altered consciousness (22.8 %). Most cases of vasospasm presented within the first week (58.4 %), with 97.7 % occurring within the first 2 weeks. A higher mortality rate was associated with onset before 3 days (n=6/13; 46.2 %). Mortality was reported in 17.3 % (n=18) of all cases and residual deficits were reported in 53.5 % (n=46) of those patients who survived. CONCLUSION: Most reports on CV involved posterior fossa tumors, the anterior circulation (most frequently the MCA), and tumors of varying histologies. Tumor location and vascular involvement may be related to distribution of spasm and symptomatology. Early onset of vasospasm may furthermore be related to poorer outcomes.

Transorbital Approach Clipping of Middle Cerebral Artery Aneurysm: A Virtual Reality Morphometric Anatomic Study.

BACKGROUND: The transorbital approach (TOA) has a unique advantage to the more common lateral approaches as it provides direct access to the anterior middle fossa and medial sylvian fissure (SF) without significant dissection or retraction. However, when to use the TOA for surgical treatment of middle cerebral artery (MCA) aneurysms remains unclear. This study details the feasibility of clipping unruptured MCA aneurysms via the TOA by highlighting the anatomic features that either facilitate or hinder the approach. METHODS: Virtual reality (VR) models of 25 MCA aneurysms from computed tomography angiograms of actual patients were rendered with the relevant anatomic structures, including the neighboring temporal lobe and SF. TOA was performed on the models in VR and the globe was translated medially and inferiorly, replicating retraction used intraoperatively. Anatomic data, including the area of surgical freedom (AOF) at the aneurysm, were recorded. Trials of aneurysm clipping were conducted in VR and each aneurysm was classified as "possible" or "impossible" candidates for clipping via TOA. Separately, the relationship between surgical view and SF visualized was analyzed. RESULTS: Sixteen aneurysms were eliminated as candidates for TOA treatment either through VR clip trial and/or because the SF was inaccessible. The remaining 9 (36%) were candidates for TOA. Comparing the details of these 2 aneurysm categories with Mann Whitney U tests, there was a statistically significant difference in the AOF of the TOA approach and the width of the aneurysm dome. A clinical case report is also provided highlighting the VR rehearsal similarity with surgery. CONCLUSIONS: Given the minimally invasive, technically challenging approach, the feasibility and safety of TOA for MCA aneurysms must be evaluated before wide clinical adoption. This study identified AOF, aneurysm width, and SF accessibility as three features that may significantly impact the possibility of clipping MCA aneurysms via TOA.

Considerations for delayed-onset spinal arachnoid web after intracranial subarachnoid hemorrhage.

Spinal arachnoid web (AW) is a rare condition causing spinal cord-related issues. Its cause is often idiopathic but can be linked to past trauma or spine surgery. We describe two cases of AWs that developed after subarachnoid hemorrhage (SAH). Case #1 is a 71-year-old male with nonaneurysmal SAH who developed myelopathy 1 year later. Magnetic resonance imaging revealed upper thoracic cord edema and an AW. Case #2 is a 57-year-old female who underwent coiling of a ruptured basilar artery aneurysm and ventriculoperitoneal shunting for hydrocephalus. Twenty months later, she developed mid-thoracic AW requiring surgical resection. Both patients showed symptom improvement postresection avoiding further reoperation. History of SAH is emerging as a risk factor for AW development, emphasizing the importance of monitoring delayed-onset myelopathy and back pain in recent SAH patients.

The Inaugural "Century" of Mixed Reality in Cranial Surgery: Virtual Reality Rehearsal/Augmented Reality Guidance and Its Learning Curve in the First 100-Case, Single-Surgeon Series.

BACKGROUND AND OBJECTIVE: Virtual reality (VR) refers to a computer-generated three-dimensional space in which a surgeon can interact with patient-specific anatomic models for surgical planning. Augmented reality (AR) is the technology that places computer-generated objects, including those made in VR, into the surgeon's visual space. Together, VR and AR are called mixed reality (MxR), and it is gaining importance in neurosurgery. MxR is helpful for selecting and creating templates for an optimal surgical approach and identifying key anatomic landmarks intraoperatively. By reporting our experience with the first 100 consecutive cases planned with VR and executed with AR, our objective is to detail the learning curve and encountered obstacles while adopting the new technology. METHODS: This series includes the first 100 consecutive complex cranial cases of a single surgeon for which MxR was intended for use. Effectiveness of the VR rehearsal and AR guidance was analyzed for four specific contributions: (1) opening size, (2) precise craniotomy placement, (3) guidance toward anatomic landmarks or target, and (4) antitarget avoidance. Seventeen cases in the study cohort were matched with historical non-MxR cases for comparison of outcome parameters. The cases in which MxR failed were plotted over time to determine the nature of the "learning curve." RESULTS: AR guidance was abandoned in eight operations because of technical problems, but problem-free application of MxR increased between the 44th and 63rd cases. This provides some evidence of proficiency acquisition in between. Comparing the 17 pairs of matched MxR and non-MxR cases, no statistically significant differences exist in the groups regarding blood loss, length of stay nor duration of surgery. Cases where MxR had above-expectation performances are highlighted. CONCLUSION: MxR is a powerful tool that can help tailor operations to patient-specific anatomy and provide efficient intraoperative guidance without additional time for surgery or hospitalization.

Relationship of Pressure Reactivity Index and Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage.

AIM: Patients with aneurysmal subarachnoid hemorrhage (SAH) continue to have poor functional outcome due to the occurrence of delayed cerebral ischemia (DCI). Although vasospasm represents the primary therapeutic target for mitigating DCI, DCI occurs through multifocal etiologies that involve impaired cerebral autoregulation. Worse pressure reactivity index (PRx) values, which consists of a moving correlation coefficient between intracranial pressures and mean arterial pressures, have been shown to be associated with DCI in non-randomized clinical trials. RESULTS: We discuss two patients that presented with high-grade SAH and comatose exams. Patient one was a 34-year-old male diagnosed with SAH from a ruptured right middle cerebral artery aneurysm. He had intact PRx values (Mean: -0.07 during hospital days 9-19), while having severe, refractory vasospasm. At the conclusion of his hospitalization, he was functionally independent, had negligible DCI, and was successfully discharged home. Patient two was a 78-year-old female diagnosed with SAH from a ruptured anterior communicating artery aneurysm. She had an improving PRx ranging from -0.1 to 0.1 early in her hospitalization. However, upon developing severe vasospasm, her PRx increased to 0.6 (overall PRx from hospital days 4-16 was 0.3), and she suffered from extensive DCI in bilateral middle cerebral and anterior cerebral artery distributions that ultimately resulted in malignant cerebral edema and brain death. CONCLUSION: Cerebral autoregulation as measured by PRx may represent a viable target for neuroprognostication by evaluating DCI risk in patients with SAH who develop severe or refractory vasospasm. Further studies evaluating the role of cerebral autoregulation, PRx, and its pathophysiological role in DCI are warranted.

Neurosurgery Subspecialty Practice During a Pandemic: A Multicenter Analysis of Operative Practice in 7 U.S. Neurosurgery Departments During Coronavirus Disease 2019.

OBJECTIVE: Changes to neurosurgical practices during the coronavirus disease 2019 (COVID-19) pandemic have not been thoroughly analyzed. We report the effects of operative restrictions imposed under variable local COVID-19 infection rates and health care policies using a retrospective multicenter cohort study and highlight shifts in operative volumes and subspecialty practice. METHODS: Seven academic neurosurgery departments' neurosurgical case logs were collected; procedures in April 2020 (COVID-19 surge) and April 2019 (historical control) were analyzed overall and by 6 subspecialties. Patient acuity, surgical scheduling policies, and local surge levels were assessed. RESULTS: Operative volume during the COVID-19 surge decreased 58.5% from the previous year (602 vs. 1449, P = 0.001). COVID-19 infection rates within departments' counties correlated with decreased operative volume (r = 0.695, P = 0.04) and increased patient categorical acuity (P = 0.001). Spine procedure volume decreased by 63.9% (220 vs. 609, P = 0.002), for a significantly smaller proportion of overall practice during the COVID-19 surge (36.5%) versus the control period (42.0%) (P = 0.02). Vascular volume decreased by 39.5% (72 vs. 119, P = 0.01) but increased as a percentage of caseload (8.2% in 2019 vs. 12.0% in 2020, P = 0.04). Neuro-oncology procedure volume decreased by 45.5% (174 vs. 318, P = 0.04) but maintained a consistent proportion of all neurosurgeries (28.9% in 2020 vs. 21.9% in 2019, P = 0.09). Functional neurosurgery volume, which declined by 81.4% (41 vs. 220, P = 0.008), represented only 6.8% of cases during the pandemic versus 15.2% in 2019 (P = 0.02). CONCLUSIONS: Operative restrictions during the COVID-19 surge led to distinct shifts in neurosurgical practice, and local infective burden played a significant role in operative volume and patient acuity.

Decompressive hemicraniectomy and cranioplasty using subcutaneously preserved autologous bone flaps versus synthetic implants: perioperative outcomes and cost analysis.

OBJECTIVE: It has not been well-elucidated whether there are advantages to preserving bone flaps in abdominal subcutaneous (SQ) tissue after decompressive hemicraniectomy (DHC), compared to discarding bone flaps. The authors aimed to compare perioperative outcomes and costs for patients undergoing autologous cranioplasty (AC) after DHC with the bone flap preserved in abdominal SQ tissue, and for patients undergoing synthetic cranioplasty (SC). METHODS: A retrospective review was performed of all patients undergoing DHC procedures between January 2017 and July 2021 at two tertiary care institutions. Patients were divided into two groups: those with flaps preserved in SQ tissue (SQ group), and those with the flap discarded (discarded group). Additional analysis was performed between patients undergoing AC versus SC. Primary end points included postoperative and surgical site complications. Secondary endpoints included operative costs, length of stay, and blood loss. RESULTS: A total of 248 patients who underwent DHC were included in the study, with 155 patients (62.5%) in the SQ group and 93 (37.5%) in the discarded group. Patients in the discarded group were more likely to have a diagnosis of severe TBI (57.0%), while the most prevalent diagnosis in the SQ group was malignant stroke (35.5%, p < 0.05). There were 8 (5.2%) abdominal surgical site infections and 9 (5.8%) abdominal hematomas. The AC group had a significantly higher reoperation rate (23.2% vs 12.9%, p = 0.046), with 11% attributable to abdominal reoperations. The average cost of a reoperation for an abdominal complication was $40,408.75 ± $2273. When comparing the AC group to the SC group after cranioplasty, there were no significant differences in complications or surgical site infections. There were 6 cases of significant bone resorption requiring cement supplementation or discarding of the bone flap. Increased mean operative charges were found for the SC group compared to the AC group ($72,362 vs $59,726, p < 0.001). CONCLUSIONS: Autologous bone flaps may offer a cost-effective option compared to synthetic flaps. However, when preserved in abdominal SQ tissue, they pose the risk of resorption over time as well as abdominal surgical site complications with increased reoperation rates. Further studies and methodologies such as cryopreservation of the bone flap may be beneficial to reduce costs and eliminate complications associated with abdominal SQ storage.

Cirq robotic arm-assisted transpedicular instrumentation with intraoperative navigation: technical note and case series with 714 thoracolumbar screws.

The Cirq is a surgeon-controlled robotic arm that provides a new technique for accurately placing transpedicular screws. This report aims to present a technical report and our experience with this new robotic arm combined with intraoperative navigation. Technique and workflow using the Cirq robotic arm with intraoperative navigation is described. A retrospective review was conducted of all patients undergoing elective open thoracic/lumbar fusion surgery by a single surgeon in the first year of using the novel Cirq robotic arm. Descriptive analysis of patient and operative variables was performed. A total of 84 patients underwent placement of a total 714 transpedicular screws using the Cirq robotic arm. Most (69.1%) underwent 3-6 level fusion procedures. Mean operative time was 198 min total and 28 min when adjusted per screw. There was a learning curve with operative time per screw decreasing from 32 to 25 min from the first to second half of cases (p = 0.057). There were no intraoperative screw revisions and 2.4% (2/84) required instrumentation revision and return to the operating room. The Cirq robotic arm is seamlessly incorporated into the workflow of a transpedicular fusion. Our experience with over 700 pedicle screw placements using the Cirq robot demonstrates efficacy and safety although further comparative studies are needed.

Middle meningeal artery embolization with subdural evacuating port system for primary management of chronic subdural hematomas.

Optimal treatment for chronic subdural hematomas remains controversial and perioperative risks and comorbidities may affect management strategies. Minimally invasive procedures are emerging as alternatives to the standard operative treatments. We evaluate our experience with middle meningeal artery (MMA) embolization combined with Subdural Evacuating Port System (SEPS) placement as a first-line treatment for patients with cSDH. A single institution retrospective review was performed of all patients undergoing intervention. Patients were stratified by treatment with MMA embolization and SEPS placement, MMA embolization and surgery, SEPS placement only, and surgery only for cSDH from 2017 to 2020, and cohorts were compared against each other. Patients treated with MMA/SEPS were more likely to be older, be on anticoagulation, have significant comorbidities, have shorter length of stay, and less likely to have symptomatic recurrence compared to SEPS only cohort. Thus, MMA/SEPS appears to be a safe and equally effective minimally invasive treatment for cSDH patients with significant comorbidities who are poor surgical candidates.

Diagnostic Evaluation and Cervical Spine Surgery in the Setting of a Cardiac Left Ventricular Assist Device: Challenges and a Case Illustration.

Due to incompatibility with magnetic resonance imaging, patients with left ventricular assist devices (LVADs) presenting with pathologies of the spinal soft tissues or neural elements represent diagnostically complex cases. We present a case of a patient undergoing a CT (computed tomography) myelogram and subsequent successful cervical posterior laminectomy. A C1-C2 lateral puncture approach CT myelogram revealed nearly a complete block of contrast movement at the level of the C2-C3 vertebrae concerning a compressive etiology. The cervical lateral approach was chosen based on patient symptomology and concern that contrast dye injected in the lumbar spine would not travel to the region of interest due to altered CSF pulsatility caused by the LVAD device. A C3-C7 posterior laminectomy was then successfully performed. Intra-operatively, however, there was no sign of a compressive lesion, and ultrasound confirmed a decompressed spinal cord. This case highlights the diagnostic challenges of pre-operative evaluation in patients with LVADs in which the efficacy of performing CT myelograms is also questionable due to potential alterations in cerebrospinal fluid movement due to variations in arterial pulsatility due to LVAD physiology.

Abnormal neurological pupil index is associated with malignant cerebral edema after mechanical thrombectomy in large vessel occlusion patients.

BACKGROUND AND OBJECTIVES: Malignant cerebral edema (MCE) is a feared complication in patients suffering from large vessel occlusion. Variables associated with the development of MCE have not been clearly elucidated. Use of pupillometry and the neurological pupil index (NPi) as an objective measure in patients undergoing mechanical thrombectomy (MT) has not been explored. We aim to evaluate variables significantly associated with MCE in patients that undergo MT and hypothesize that abnormal NPi is associated with MCE in this population. METHODS: A retrospective analysis of patients with acute ischemic stroke who had undergone MT at our institution between 2017 and 2020 was performed. Baseline and outcome variables were collected, including NPi values from pupillometry readings of patients within 72 h after the MT. Patients were divided into two groups: MCE versus non-MCE group. A univariate and multivariate analysis was performed. RESULTS: Of 284 acute ischemic stroke patients, 64 (22.5%) developed MCE. Mean admission glucose (137 vs. 173; p < 0.0001), NIHSS on admission (17 vs. 24; p < 0.01), infarct core volume (27.9 vs. 17.9 mL; p = 0.0036), TICI score (p = 0.001), and number of passes (2.9 vs. 1.8; p < 0.0001) were significantly different between the groups. Pupillometry data was present for 64 patients (22.5%). Upon multivariate analysis, abnormal ipsilateral NPi (OR 21.80 95% CI 3.32-286.4; p = 0.007) and hemorrhagic conversion were independently associated with MCE. CONCLUSION: Abnormal NPi and hemorrhagic conversion are significantly associated with MCE in patients following MT. Further investigation is warranted to better define an association between NPi and patient outcomes in this patient population.

Inadvertent intrathecal administration of daunomycin resulting in fatality: Case report and therapeutic considerations.

BACKGROUND: Daunomycin is a chemotherapeutic agent of the anthracycline family that is administered intravenously, most commonly in combination therapy. The authors report the first known adult case of inadvertently administered daunomycin directly into the human central nervous system and the neurologic manifestations and therapeutic interventions that followed. CLINICAL DESCRIPTION: A 53-year-old male presenting to the hospital for his second cycle of consolidation therapy for acute promyelocytic leukemia t(15;17) was accidentally administered 93 mg of intrathecal (IT) daunomycin. Within several hours of injection, the patient subsequently developed bilateral lower extremity pain, ascending paresthesias, headache, and left cranial nerve (CN) III palsy. Immediately following these neurologic sequalae, a subarachnoid lumbar drain was placed at the L4-5 interspace for the initial irrigation and drainage of cerebrospinal fluid (CSF). By hospital day 2, the patient's mental status significantly declined requiring an external ventricular drain (EVD) for hydrocephalus. Despite therapeutic interventions, the patient developed an ascending radiculomyeloencephalopathy with deterioration in clinical status. Eighteen days after the inadvertent injection of IT daunomycin, the patient became comatose and lost all cranial nerve function. CONCLUSIONS: Accidental IT injection of daunomycin is a neurosurgical emergency and warrants prompt intervention. Symptoms can mimic other medical conditions, making it imperative an accurate diagnosis is made so that appropriate therapies are implemented. At this time, therapies include rapid removal of the chemotherapeutic agent from the IT compartment by aspiration and irrigation; however, it is unclear if neuroprotective agents may provide added benefit.

Management of Intracranial Hemorrhage in Patients with a Left Ventricular Assist Device: A Systematic Review and Meta-Analysis.

BACKGROUND: Intracranial hemorrhage (ICH) has been reported to occur in up to 23% of patients with left ventricular assist devices (LVADs). Currently, limited data exists to guide neurosurgical management strategies to optimize outcomes in patients with an LVAD who develop ICH. METHODS: A systematic review and meta-analysis of the literature was performed to evaluate the mortality rate in these patients following medical and/or surgical management and to evaluate antithrombotic reversal and resumption strategies after hemorrhage. RESULTS: 17 studies reporting on 3869 LVAD patients and 545 intracranial hemorrhages spanning investigative periods from 1996 to 2019 were included. The rate of ICH in LVAD patients was 10.6% (411/3869) with 58.6% (231/394) being intraparenchymal hemorrhage (IPH), 23.6% (93/394) subarachnoid hemorrhage (SAH), and 15.5% (61/394) subdural hemorrhage (SDH). Total mortality rates for surgical management 65.6% (40/61) differed from medical management at 45.2% (109/241). There was an increased relative risk of mortality (RR=1.45, 95% CI: 1.10-1.91, p = 0.01) for ICH patients undergoing surgical intervention. The hemorrhage subtype most frequently managed with anticoagulation reversal was IPH 81.8% (63/77), followed by SDH 52.2% (12/23), and SAH 39.1% (18/46). Mean number of days until antithrombotic resumption ranged from 6 to 10.5 days. CONCLUSION: Outcomes remain poor, specifically for those undergoing surgery. As experience with this population increases, prospective studies are warranted to contribute to management and prognostication .

The Use of Augmented Reality to Improve Safety of Anterior Petrosectomy: Two-Dimensional Operative Video.

An anterior petrosectomy (AP) provides access to the upper petroclival region, but approach-related complications include seizures and temporal lobe hematomas.1 Moreover, the floor of the middle fossa contains multiple critical neurovascular structures, and drilling Kawase's quadrilateral must be performed carefully to avoid iatrogenic injury. In particular, the cochlea, carotid artery, and the contents of the internal acoustic canal are vulnerable because there are no locational cues to help the surgeon define their borders.2-4 In this video, we demonstrate the use of an augmented reality (AR) to protect critical structures during drilling of an AP. The illustrative case involves a 70-year-old woman with difficulty walking caused by a petrotentorial meningioma. The 3-dimensional, virtual reality rendering (Surgical Theater SRP7.4.0, Cleveland, Ohio, USA) of her patient-specific anatomy was enhanced by "painting" the cochlea, petrous carotid, labyrinthine, and the plane of the internal acoustic canal. This process takes 30-60 minutes, and the resulting rendering was used for surgical rehearsal to optimize the AP for tumor exposure. At surgery, our unique AR technique projects the painted anatomic landmarks into the eye-piece of the navigation-tracked microscope (Surgical Theater Sync AR v.3.8.0). Drilling is performed while the critical structures are visible in AR, superimposed on the patient's anatomy in real-time. The AP in surgery mimicked the one practiced during rehearsal and provided exposure to our patient's tumor. After surgery, the patient awoke without injury to her hearing, balance, or facial movements. By providing visual locational cues to the surgeon, we believe that AR improves the safety to the critical neurovascular structures during AP.

Optimization of skull base exposure using navigation-integrated, virtual reality templates.

In many skull base procedures, arriving at the optimal bone exposure is important. Whereas insufficient exposure can jeopardize the operation itself, over-doing the exposure might lead to complications. We developed a new technique, harnessing the strength of Virtual Reality (VR) technology in planning, rehearsal and navigation, to achieve the optimal skull base exposure for resection of tumors. VR models of patient-specific anatomy were used to rehearse the surgical exposure. From the altered models, the one with the ideal exposure was chosen, integrated with the navigation system in the operating suite, and used as a template to achieve the optimal exposure in surgery. The use of these VR templates is demonstrated in two cases involving skull base tumors. In both cases, over-zealous bone removal could have increased the risk of complications, and inadequate exposure would jeopardize the tumor resection. Navigation guided by the VR templates aided the creation of the "ideal" surgical exposure to reach the surgical goals. Complete resections were achieved and neither patient suffered any approach-related complications. In conclusion, virtual reality is a powerful tool to improve the safety and efficacy of neurosurgical procedures. With preoperatively-altered VR templates, the surgeon is no longer navigating just to find bearings, but to duplicate an opening designed to simultaneously provide sufficient exposure while limiting postoperative complications. Intuitively useful and successful in early application, there has been no identifiable disadvantages to date.

The impact of COVID-19 on neurosurgeons and the strategy for triaging non-emergent operations: a global neurosurgery study.

OBJECT: The COVID-19 pandemic has disrupted all aspects of society globally. As healthcare resources had to be preserved for infected patients, and the risk of in-hospital procedures escalated for uninfected patients and staff, neurosurgeons around the world have had to postpone non-emergent procedures. Under these unprecedented conditions, the decision to defer cases became increasingly difficult as COVID-19 cases skyrocketed. METHODS: Data was collected by self-reporting surveys during two discrete periods: the principal survey accrued responses during 2 weeks at the peak of the global pandemic, and the supplemental survey accrued responses after that to detect changes in opinions and circumstances. Nine hypothetical surgical scenarios were used to query neurosurgeons' opinion on the risk of postponement and the urgency to re-schedule the procedures. An acuity index was generated for each scenario, and this was used to rank the nine cases. RESULTS: There were 494 respondents to the principal survey from 60 countries. 258 (52.5%) reported that all elective cases and clinics have been shut down by their main hospital. A total of 226 respondents (46.1%) reported that their operative volume had dropped more than 50%. For the countries most affected by COVID-19, this proportion was 54.7%. There was a high degree of agreement among our respondents that fast-evolving neuro-oncological cases are non-emergent cases that nonetheless have the highest risk in postponement, and selected vascular cases may have high acuity as well. CONCLUSION: We report on the impact of COVID-19 on neurosurgeons around the world. From their ranking of the nine case scenarios, we deduced a strategic scheme that can serve as a guideline to triage non-emergent neurosurgical procedures during the pandemic. With it, hopefully, neurosurgeons can continue to serve their patients without endangering them either neurologically or risking their exposure to the deadly virus.

Intracranial hemorrhage type and same-admission mortality in patients with left ventricular assist devices.

OBJECTIVES: Left ventricular assist devices (LVAD) provide mechanical circulatory support for patients with advanced heart failure. Intracranial hemorrhage in this population represent a significant management challenge. The objective of this study is to report our initial experience on same-admission outcomes with LVAD patients that presented with various types of intracranial hemorrhage (ICH). PATIENTS AND METHODS: A retrospective review of a large volume center over a two-year period was performed. LVAD patients with ICH requiring a neurosurgical consultation were identified. Hemorrhage type, interventions, discharge disposition and cause of death were recorded. RESULTS: 27 LVAD patients with ICH received a neurosurgical consultation. The average INR at the time of ICH was 2.7 (1.0-8.8). Hemorrhage types seen were lobar (10/27, 37 %), SAH (5/27, 19 %), SDH (4/27, 15 %), cerebellar ICH (3/27, 11 %), multiple ICH (3/27, 11 %), and hemorrhagic conversion (2/27, 7 %). The overall mortality rate was 48.2 % (13/27), with the highest mortality being in those patients who had multiple ICH at the time of presentation (3/3, 100 %). The majority of patients with ICH (85.2 %) were non-operative. Lobar IPH was <3 cm in 80 % (8/10) of these, and 6/8 (75 %) ultimately died. 11 %(3/27) received surgical intervention. Of these, 67 % ultimately withdrew care. 77 % (10/13) of patients died as a result of the ICH. 80 % of patients with SAH were ultimately discharged home. CONCLUSIONS: Patients with a LVAD and ICH have a high rate of same-admission mortality (48 %). Hemorrhage location, intra-axial or extra-axial, resulted in patients being a risk for death secondary to either the hemorrhage itself or pump thrombosis, respectively.

Outcome of Microsurgery for Arteriovenous Malformations in a Resource-Restricted Environment: Single-Surgeon Series from Vietnam.

BACKGROUND: The health care expenditure in Vietnam is equivalent to 1% of that in the United States. For most patients with brain arteriovenous malformations (AVM), surgery is the only available treatment modality. This study reports on the outcomes on AVM microsurgery in this resource-restricted environment. METHODS: This is a prospectively collected, retrospectively analyzed case series of consecutive patients who underwent surgical resection of AVM by a single surgeon in Vietnam. All surgeries were performed in a 3-year period in Hanoi. The primary endpoints were obliteration of the AVM and surgical morbidity (modified Rankin Scale [mRS] > 1). RESULTS: There were 86 patients and 62% presented with hemorrhage. Only 2 patients had preoperative embolization, and 47 patients (54%) had preoperative digital subtraction angiography. All patients underwent microsurgical resection of their AVM. Excluding the 4 patients who died, the AVM obliteration rate was 98%. The mean follow-up was 20.1 months. Before surgery, 36% of patients had at least some disability (mRS > 1). Postoperatively, this was reduced to 10% (McNemar P = 0.007). For the overall cohort, neurologic status was improved from initial encounter to final assessment (P = 0.001). Because of resource restrictions, some patients with hemorrhage experienced delays in treatment. There was no difference in outcome between patients who were admitted before or after 24 hours post ictus (P = 0.6). The days spent waiting for surgery did not correlate with final mRS in univariate regression (R2 = 0.01). CONCLUSIONS: Notwithstanding the limitation in health care resources in Vietnam, surgery for AVMs was successful in eliminating the malformation, with obliteration rates and morbidity comparable with international standards.

An anatomical study of the foramen of Monro: implications in management of pineal tumors presenting with hydrocephalus.

BACKGROUND: For pineal tumors presenting with hydrocephalus, simultaneous endoscopic third ventriculostomy (ETV) and tumor biopsy is commonly used as the initial step in management. To analyze the restriction which the foramen of Monro poses to this procedure, one must start with a detailed description of the microsurgical anatomy of the foramen in living subjects. However, the orientation and shape of the foramen of Monro make this description difficult with conventional imaging techniques. METHOD: Virtual reality technology was applied on MRIs on living subject without hydrocephalus, as well as patients with hydrocephalus, to generate precise anatomical models with sub-millimeter accuracy. The morphometry of the foramen of Monro was studied in each group. In addition, displacement of the margins of the foramen was studied in detail for simultaneous ETV and pineal tumor biopsy through a single burr hole. RESULTS: In 30 normal subjects, the foramen of Monro had oval-shaped openings averaging 5.23 mm2. The foramen was larger in people above age 55 (p = 0.007) and on the left side compared to the right (p = 0.002). For patients with clinical presentation of hydrocephalus, the average opening was 32.6 mm2. Simulated single burr hole simultaneous ETV and pineal tumor biopsy was performed in 10 specimens. Average displacement of the posterior and anterior margins of the foramen was 5.71 mm and 5.76 mm, respectively. However, maximum displacement reached 9.3 mm posteriorly and 10 mm anteriorly. CONCLUSIONS: The foramen of Monro is an oval-shaped cylinder that changes in size and orientation in the hydrocephalic patient. If universally applied to all patients regardless of foramen and tumor size, ETV/biopsy can displace structures around the Foramen of Monro up to 1 cm, which can potentially lead to neurological damage. Careful pre-operative assessment is critical to determine if a single burr hole approach is safe.