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The current treatment paradigm for intracranial arteriovenous malformations (AVMs) focuses on reducing the risk of intracranial hemorrhage using various therapeutic means including embolization, stereotactic radiosurgery (SRS), and microsurgical resection. To improve AVM obliteration rates with SRS, pre-radiosurgical embolization has been trialed in a number of studies to reduce the volume of the AVM nidus prior to radiosurgery. This study aimed to review the efficacy of pre-radiosurgical embolization in the pre-Onyx era compared to the current Onyx era.A systematic review was performed using PubMed to identify studies with 20 or more AVM patients, embolization material, and obliteration rates for both embolization + stereotactic radiosurgery (E+SRS) and SRS-only groups.Seventeen articles consisting of 1133 eligible patients were included in this study. A total of 914 (80.7%) patients underwent embolization prior to SRS. Onyx was used as the embolysate in 340 (37.2%) patients in the E+SRS cohorts. Mean obliteration rate for the embolized cohort was 46.9% versus 46.5% in the SRS-only cohort. When comparing obliteration rates based on embolysate material, obliteration rate was 42.1% with Onyx+SRS and 50.0% in the non-Onyx embolysate + SRS cohort.Onyx (ethylene vinyl-alcohol copolymer dissolved in dimethyl sulfoxide and suspended in micronized tantalum powder) has been increasingly used for the embolization of intracranial AVMs with increased success regarding its ease of use from a technical standpoint and performs similarly to other embolysate materials.

Background and Purpose The goal of this study was to systematically review the utility of serum biomarkers in the setting of ischemic stroke (IS) to predict long-term outcome. Methods A systematic literature review was performed using the PubMed and MEDLINE databases for studies published between 1986-2018. All studies assessing long-term functional outcome (defined as 30 days or greater) following IS with respect to serum biomarkers were included. Data were extracted and pooled using a meta-analysis of odds ratios. Results Of the total 2928 articles in the original literature search, 183 studies were ultimately selected. A total of 127 serum biomarkers were included. Biomarkers were grouped into several categories: inflammatory (32), peptide/enzymatic (30), oxidative/metabolic (28), hormone/steroid based (23), and hematologic/vascular (14). The most commonly studied biomarkers in each category were found to be CRP, S100β, albumin, copeptin, and D-dimer. With the exception of S100β, all were found to be statistically associated with >30-day outcome after ischemic stroke. Conclusions Serum-based biomarkers have the potential to predict functional outcome in IS patients. This meta-analysis has identified CRP, albumin, copeptin, and D-dimer to be significantly associated with long-term outcome after IS. These biomarkers have the potential to serve as a platform for prognosticating stroke outcomes after 30 days. These serum biomarkers, some of which are routinely ordered, can be combined with imaging biomarkers and used in artificial intelligence algorithms to provide refined predictive outcomes after injury. Ultimately these tools will assist physicians in providing guidance to families with regards to long-term independence of patients.

Objective Clopidogrel is a commonly used antiplatelet agent for the prevention of thromboembolic complications following neuroendovascular procedures, but anecdotal data have raised concern for the possibility that clopidogrel may induce severe, intolerable fatigue. The purpose of this study is to systematically investigate this phenomenon. Methods We performed a dual-institution, 9-year, retrospective study of patients undergoing clopidogrel therapy for neuroendovascular procedures. Patients were included only if their response to clopidogrel was assessed by platelet function testing using the VerifyNow P2Y12 (VNP) assay. Hyperresponse to clopidogrel was defined as P2Y12 reaction units ≤60. Patients were considered to have had clopidogrel-induced severe fatigue if the onset of symptoms followed the initiation of clopidogrel therapy; symptoms improved following a reduction in the dose of clopidogrel; and symptoms could not be attributed to any other medical explanation. Results Data were collected on 349 patients. Five patients (1.4%) met criteria for clopidogrel-induced severe fatigue. All 5 patients were female, ages 39–68. VNP assessments obtained while patients were symptomatic revealed hyperresponse to clopidogrel (0–22 P2Y12 reaction units). Symptoms improved in all 5 patients when the dose of clopidogrel was reduced by half. Notably, 30% of patients (n = 103) demonstrated a hyperresponse to clopidogrel on at least 1 VNP assessment, but 98 of these patients did not suffer from severe fatigue. Conclusions A syndrome of severe fatigue and other constitutional symptoms is a rare but clinically significant side effect of hyperresponse to clopidogrel in patients undergoing neuroendovasular intervention.

Objective The Prospective, Multicenter Registry Assessing the Embolization of Neurovascular Lesions Using the Penumbra SMART COIL® System (SMART) is the largest prospective, multicenter, postmarket registry established to gather real-world experience on Penumbra (Alameda, USA) SMART COIL System, PC400, and POD embolization coils. The goal of this study is to report the technical success and efficacy of SMART COIL System coils in treating saccular intracranial aneurysms. Methods This subgroup analysis from the SMART registry included patients with saccular intracranial aneurysms treated using ≥75% SMART COIL System or PC400 coils. Baseline and procedural data, angiographic data, and clinical outcomes were collected. Predictors of catheter kickout, packing density, and postprocedural angiographic outcome were analyzed using multivariable regression models in saccular aneurysm cases. Results Between June 2016 and August 2018, the SMART registry enrolled 995 patients at 68 sites, of which 851 of 995 (85.5%) were treated for saccular aneurysms (mean age, 59.9 years). Aneurysms had a mean size of 6.8 mm, were wide neck in 63.1%, and ruptured in 31.0% of patients. Mean aneurysm packing density was 32.3%. Postprocedural Raymond-Roy Occlusion Classification (RROC) I–II was achieved in 80.3% of patients; smaller aneurysms, non–wide-neck aneurysms, and high packing density were predictive of RROC I–II. Overall, mean fluoroscopic time was 43.4 minutes, rate of reaccess attempts because of catheter kickout was 6.2%, and mean procedure time was 83.2 minutes. Conclusions SMART COIL System coils achieved good technical success and adequate occlusion in treating saccular intracranial aneurysms in a real-world setting.

Intra-operative ultrasound has become a relevant imaging modality in neurosurgical procedures. While B-mode, with its intrinsic limitations, is still considered the primary ultrasound modality, intra-operative contrast-enhanced ultrasound (ioCEUS) has more recently emerged as a powerful tool in neurosurgery. Though still not used on a large scale, ioCEUS has proven its utility in defining tumor boundaries, identifying lesion vascular supply and mapping neurovascular architecture. Here we propose a step-by-step procedure for performing ioCEUS analysis of the brain, highlighting its neurosurgical applications. Moreover, we provide practical advice on the use of ultrasound contrast agents and review technical ultrasound parameters influencing ioCEUS imaging.

Objective A review of endovascular cerebral mycotic aneurysm treatment with Onyx liquid embolic, N-butyl-2-cyanoacrylate (NBCA), or coil embolization has not been reported. The authors conduct a systematic review on endovascular treatment methods of mycotic aneurysms. Methods A systematic literature review was performed using the PubMed and MEDLINE databases for studies published between 1986 and 2020. All studies assessing outcomes related to endovascular Onyx embolization, NBCA embolization, or coiling were included. Results A total of 74 studies were ultimately selected, including 180 (67% male) patients comprising 243 aneurysms treated endovascularly. The mean age was 38.2 ± 17.6 years, and the most common symptom on presentation was headache (31%). Most aneurysms were located on the middle cerebral artery (52.5%), and over half presented with rupture (53.8%). Coiling was the most commonly employed technique (50.4%), and obliteration rates were comparable across coiling, NBCA, and Onyx (99.1%, 100%, 100%, respectively). Complication rates were also comparable (4.3% vs. 15.2% vs. 8.1%). Conclusion Embolization for infectious intracranial aneurysm appears to be an effective treatment option for mycotic aneurysms. Embolization rates were comparable between coiling, NBCA, and Onyx embolization. Noninferiority among these modalities cannot be demonstrated given the retrospective nature of this review, evolution of endovascular techniques over the years, and changes in treatment paradigms in the last 2 decades. Ideally, further prospective research will be needed to find which treatment method offers the lowest complication rates and the best outcomes for patients with mycotic aneurysms.

Background Mechanical thrombectomy (MT) is the standard of care for the treatment of proximal anterior circulation large vessel occlusions. However, little is known about its efficacy and safety in the treatment of distal intracranial occlusions. Methods This is a multicenter retrospective study of patients treated with MT at 15 comprehensive centers between January 2015 and December 2018. The study cohort was divided into 2 groups based on the location of occlusion (proximal vs. distal). Distal occlusion was defined as occlusion of M3 segment of the middle cerebral artery, any segment of the anterior cerebral artery, or any segment of the posterior cerebral artery. Only isolated distal occlusion was included. Good outcome was defined as 90-day modified Rankin scale score 0–2. Results A total of 4710 patients were included in this study, of whom 189 (4%) had MT for distal occlusions. Compared with the proximal occlusion group, distal occlusion group had a higher rate of good outcome (45% vs. 36%; P = 0.03) and a lower rate of successful reperfusion (78% vs. 84%; P = 0.04). However, the differences did not retain significance in adjusted models. Otherwise there was no difference in the rate of hemorrhagic complications, mortality, or procedure-related complications between the 2 groups. Successful reperfusion, age, and admission stroke severity emerged as predictors of good functional outcome in the distal occlusion group. Conclusions Thrombectomies of distal vessels achieve high rate of successful reperfusion with similar safety profile to those in more proximal locations.

Background Dissecting aneurysms of the posterior cerebral circulation can wield significant treatment challenges with devastating clinical outcomes. Despite an expanded therapeutic armamentarium, these vascular lesions remain relatively difficult to diagnose and portend high associated morbidity and mortality. Methods A ruptured, fusiform, dissecting aneurysm of the mid V4 segment of the right vertebral artery (VA) distal to the posterior inferior cerebellar artery origin resulted in a Hunt and Hess grade 5, Fisher scale score 4 subarachnoid hemorrhage. The lesion incorporated 360 degrees of the vessel wall and extended across an area measuring 11 mm in length and 6.8 mm in width at maximum dimension. The vascular lesion was treated with 2 overlapping Pipeline Embolization Devices. Results Digital subtraction angiography demonstrated an origin of the right posterior inferior cerebellar artery mildly stenosed by the dissecting aneurysm. The left VA was markedly hypoplastic. After deployment of 2 overlapping Pipeline Embolization Devices, the aneurysm neck was well covered with appropriate positioning of the stent construct with good apposition to the vessel wall. There was contrast stasis within the aneurysm. The patient was managed with dual antiplatelet therapy. He demonstrated initial clinical and radiographic improvement. However, on the night of the second postprocedure day, the patient succumbed to rerupture of the aneurysm. Conclusions The literature posits that nonsaccular, fusiform, and dissecting aneurysms of the vertebrobasilar circulation can be occluded with consistency and success using flow diversion techniques. Endovascular treatment of a ruptured dissecting aneurysm of the VA is technically feasible and can be performed with or without parent artery occlusion. Outcomes following flow diversion of the posterior circulation may depend on the location of the dissection and viability of collateral circulation. In the present case, adequate coverage of the aneurysm did not portend a positive outcome.

Background Aneurysmal subarachnoid hemorrhage (aSAH) is a debilitating disease process accounting for 5% of strokes. Although improvements in care have reduced the case-fatality rates, patients have an increased risk of neurological and medical complications after discharge. Additionally, the readmission rates have been increasingly used as a metric for patient care quality. Methods In the present study, we reviewed the medical records of 206 patients who had been treated for aSAH at the University of Virginia from 2011 to 2018 to identify the causes and predictors of readmission. Results The all-cause readmission rate was 9.8%, 15.3%, and 21.3% within 30, 60, and 180 days, respectively. The readmission rate for neurologic causes was 7.7%, 12.6%, and 18.0% within 30, 60, and 180 days, respectively. The neurologic causes of readmission included aneurysm retreatment, cranioplasty, a fall, hydrocephalus, stroke symptoms, and syncope. Surgical treatment (odds ratio [OR], 4.11–6.30) and endovascular treatment (OR, 3.79–8.33) of vasospasm were associated with an increased risk of all-cause readmission. Endovascular aneurysm treatment (OR, 0.22) was associated with a decreased risk of all-cause readmission. The average interval to the first follow-up appointment at our institution was 55.3 ± 63.3 days. Of the patients who had been readmitted from the emergency room, 65% had not had follow-up contact with physicians at our institution until their readmission. Conclusions To the best of our knowledge, the present study is the first to have examined the readmission rates for subarachnoid hemorrhage >90 days after treatment. Our results have suggested that the readmission rates >90 days after treatment could still be predicted by the hospital and treatment course during admission and that follow-up appointments with patients earlier in the clinic could identify those patients with a greater risk of readmission.

In the last forty years, the field of medicine has experienced dramatic shifts in technology-enhanced surgical procedures – from its initial use in 1985 for neurosurgical biopsies to current implementation of systems such as magnetic-guided catheters for endovascular procedures. Systems such as the Niobe Magnetic Navigation system and CorPath GRX have allowed for utilization of a fully integrated surgical robotic systems for perioperative manipulation, as well as tele-controlled manipulation systems for telemedicine. These robotic systems hold tremendous potential for future implementation in cerebrovascular procedures, but lack of relevant clinical experience and uncharted ethical and legal territory for real-life tele-robotics have stalled their adoption for neurovascular surgery, and might present significant challenges for future development and widespread implementation. Yet, the promise that these technologies hold for dramatically improving the quality and accessibility of cerebrovascular procedures such as thrombectomy for acute stroke, drives the research and development of surgical robotics. These technologies, coupled with artificial intelligence (AI) capabilities such as machine learning, deep-learning, and outcome-based analyses and modifications, have the capability to uncover new dimensions within the realm of cerebrovascular surgery.

Cerebral edema is a major cause of morbidity in patients with severe traumatic brain injury (TBI). Intraparenchymal thermal conductivity-based probes that measure local cerebral blood flow can measure percent brain tissue water (%BTW) content, but such measures have been insufficiently characterized in patients with TBI.We retrospectively reviewed physiologic data from patients with severe TBI treated at our institution (2014-2016) who underwent cerebral blood flow monitoring.Sixteen patients underwent focal %BTW measurements at a 15-minute sampling rate. %BTW measurements showed characteristic temporal profiles, with a mean time to peak of 3.7 ± 1.7 days. The mean minimum and maximum %BTWs were 71.0 ± 3.9% and 82.7 ± 7.4%, respectively (overall mean %BTW, 77.0 ± 2.9%). Intracranial pressure (ICP) values of 22 mm Hg (the current treatment threshold for patients with trauma) corresponded to 75.8 ± 5.4 %BTW. Repeated measures correlation showed that %BTW is negatively correlated with serum sodium concentration (r = -0.3; P0.001) and weakly positively correlated with ICP (r = 0.08; P = 0.01) and regional cerebral blood flow (r = 0.06; P0.001). These effects were consistent in a multivariable model including time from injury. In the best model, time was modeled as a quadratic term because the %BTW followed a parabolic trajectory.%BTW may be a clinically useful, real-time measurement of cerebral edema in patients with TBI. It is closely associated with the serum sodium concentration and follows a characteristic temporal course with characteristic trajectory and stability over time.

Background Reversible cerebral vasoconstriction syndrome (RCVS) is a rare complication after carotid endarterectomy (CEA). Only a limited number of prior cases of RCVS have been reported after CEA for asymptomatic carotid stenosis. Case Description In this report we present an unusual case of RCVS associated with multifocal intraparenchymal hemorrhage, subarachnoid hemorrhage, subdural hematoma, and ischemic stroke after CEA for asymptomatic carotid stenosis. We review preexisting studies and draw correlations with implications for understanding the mechanisms of RCVS. Conclusions A high index of suspicion should be maintained in post-CEA patients presenting with headaches or focal neurologic deficits, and vigilance with serial vascular imaging may help minimize long-term complications.

Predicting future hemorrhage risk may allow better selection of patients with cerebral cavernous malformations (CCMs) who will likely benefit from treatment. In this study, we sought to identify predictors of CCM hemorrhage, and to compare subsequent symptomatic hemorrhage risks between patients with and without previous hemorrhage.We performed a retrospective review of consecutive CCM patients at our institution between 1982 and 2017. Patients with diffuse or familial CCM syndromes, and those without follow-up data were excluded. The primary endpoint was acute symptomatic hemorrhage causing transient or permanent neurological symptoms. Primary endpoint incidences were compared between patients with and without previous hemorrhage.The study cohort comprised 84 patients with 90 CCMs. Previous hemorrhage was the only significant predictor for the primary endpoint (P = 0.003). CCMs with previous hemorrhage had a higher risk of symptomatic hemorrhage in follow-up than those without previous hemorrhage (26.9 vs. 1.5 symptomatic hemorrhages per 1000 CCM-months, P0.001). CCMs with and without previous hemorrhage had annual hemorrhage rates of 2.7% and 0.15%, respectively. Symptomatic hemorrhage-free survival rates were significantly lower in CCMs with previous hemorrhage (log-rank test, P0.001). Actuarial hemorrhage-free survival rates for CCMs with previous hemorrhage were 75%, 60%, 60%, and 60% at 1, 2, 3, and 4 years, respectively, compared with rates of 95%, 95%, 95%, and 84% for CCMs without previous hemorrhage.Previous hemorrhage is a predictor of subsequent symptomatic hemorrhage in CCMs. Compared with CCMs without previous hemorrhage, those with prior hemorrhage have a significantly higher risk of future symptomatic hemorrhage.

The overall safety and efficacy of flow diverting stents (FDSs) deployed in small caliber parent arteries (≤2.5 mm) for the treatment of intracranial aneurysms remains unclear. Recent studies have provided additional outcomes data to assess the use of FDSs for such arteries. In the present review, we have summarized the reported clinical and angiographic outcomes of FDS-treated brain aneurysms in small parent arteries.A systematic literature review was performed for outcomes data related to FDS-treated intracranial aneurysms using PubMed, Ovid Medline, and Web of Science. Procedural data, angiographic outcomes, and clinical outcomes at various time points were collected and summarized.The 19 studies included 580 patients with 604 aneurysms, of which 6.1% had been acutely ruptured and 28.3% had been previously treated. The procedural complication rate and symptomatic stroke rate was 9.8% and 7.5%. The complete occlusion rate at the last radiographic follow-up (mean, 12.1 months) was 73.6%. At the last clinical follow-up (mean, 10.6 months), the FDS-associated mortality was 2.5%.FDSs for the treatment of intracranial aneurysms located in small caliber arteries was associated with rates of long-term complete aneurysm occlusion, mortality, and permanent neurologic deficit comparable to the rates with FDS-treated aneurysms in larger parent arteries. However, the relatively increased risk of symptomatic stroke of these FDS-treated aneurysms should not be ignored. Direct comparisons with alternative endovascular approaches are necessary to further define the optimal use of FDS for these aneurysms.

Neoadjuvant endovascular embolization of skull base meningiomas may facilitate surgical resection, thereby potentially decreasing operative morbidity. However, due to variation in the reported efficacy and complication rates, the utility of embolization remains incompletely defined. The aim of this systematic review is to assess the outcomes of preoperative embolization for skull base meningiomas. A literature review was performed to identify studies reporting outcomes of patients with skull base meningiomas who underwent preoperative embolization. Baseline, treatment, and outcomes data were analyzed. Major complications included death, new cranial neuropathy, retinal artery ischemia, permanent neurologic deficit, or intracerebral hemorrhage. The pooled analysis consisted of 15 studies, comprising a total of 403 patients with skull base meningiomas treated with preoperative embolization. The most common locations were the sphenoid wing (34%, 87/256 cases), petroclival region (31%, 80/256 cases), and cavernous sinus (12%, 31/256 cases). The median tumor size ranged from 5.0 to 8.0 cm. Based on pooled data, angiographic absence of tumor blush was achieved in 17% (13/79 cases). The median estimated blood loss (EBL) ranged from 225 to 580 mL. Simpson grade I-III resection was achieved in 74% (40/54) of patients. The overall complication, major complication, and mortality rates were 12% (47/403 patients), 6% (21/328 patients), and 0.2% (1/403 patients), respectively. Preoperative embolization is a reasonable adjunct to resection for appropriately selected skull base meningiomas. Future comparative analyses are necessary to ascertain the benefits of preoperative embolization of skull base meningiomas with respect to extent of resection, operative duration, operative blood loss, and surgical morbidity.

The present study aimed to triggering of growth, lipid and fatty acids production of oceanic microalgae Tetraselmis sp. for biofuel production under mutagenic treatment with ethyl methanesulfonate (EMS). The maximum optical density (0.51 ± 0.02), cells concentration (138 ± 6.9 × 104 cells mL−1), biomass (0.63 ± 0.03 g L−1), chlorophyll ‘a’ (3.91 ± 0.19 mg L−1) were found in DKMK06 in first generation which was treated with EMS at 50 μmol mL−1 for 60 min. DKMK06 was exhibited the highest lipid productivity (48 ± 0.9%) during first generation and DKMK05 during second and third generations and percentages of lipid were 46.5 ± 1.1 and 41 ± 1.1%. The same trend has been observed in FAME contents and highest saturated and mono unsaturated fatty acid combinations were found in DKMK05 in 2nd generation (42.49%) followed by third generation (41.5%) which were higher than the first generation produced by DKMK06 (39.98%).

Hereditary hemorrhagic telangiectasia (HHT) is characterized by recurrent spontaneous epistaxis, mucocutaneous telangiectases, and multisystem arteriovenous malformations (AVMs). Brain AVMs typically present at birth and are identified in approximately 10-20% of patients with HHT. A retrospective review was undertaken of all HHT patients with known single or multiple brain AVMs treated at our institution. Thirty-nine patients with brain AVM(s) were diagnosed with HHT. Most patients presented with at least one Curaçao criterion. A total of 78 brain AVMs were identified in 39 patients. Two-thirds of patients had solitary brain AVMs, whereas 33% of patients harbored at least two lesions (range: 2-16). Brain AVMs of the supratentorial cerebral hemispheres comprised 83% of all lesions, whereas infratentorial lesions accounted for only 17%. Of the 55 brain AVMs assigned Spetzler-Martin grading, the majority of patients were Grade 1 (73%), and 23% and 4% were Grades 2 and 3, respectively. Patients were treated with surgery alone (51%), embolization alone (6%), embolization followed by surgery (9%), stereotactic radiosurgery (11%), stereotactic radiosurgery followed by surgery (3%), or observation (20%). Of patients who underwent genetic analysis, 62% possessed mutations in ENG (HHT type 1), whereas 38% had mutations in ACVRL1 (HHT type 2). This robust patient cohort of brain AVMs in 39 patients with HHT advances the collective understanding of this disease's varied presentation, diagnostic workup, genetic underpinnings, and available treatment options.

Background Endovascular mechanical thrombectomy (EMT) is the standard of care for eligible patients presenting with anterior circulation acute ischemic stroke (AIS) due to emergent large vessel occlusion (ELVO). The aim of this systematic review and meta-analysis is to compare the outcomes between patients undergoing general anesthesia (GA) versus conscious sedation (CS) for these procedures. Methods A literature review was performed to identify studies reporting the EMT outcomes of AIS patients who underwent GA or CS for the procedure. Baseline, treatment, and outcomes data were analyzed. Good outcome was defined as a modified Rankin Scale score of 0–2 at 3 months, and successful reperfusion was defined as modified thrombolysis in cerebral infarction grade of 2b–3. Results Nine studies, comprising a total of 1379 patients treated with GA (n = 761) or CS (n = 618) for EMT, were included. Based on pooled data, GA achieved good outcome in 35% and successful reperfusion in 81%, whereas CS achieved good outcome in 41% and successful reperfusion in 75%. Meta-analyses showed no significant differences in the rates of good outcome (P = 0.51) or successful reperfusion (P = 0.39) between the GA and CS groups. The rates of pneumonia were significantly higher in the GA group (21% vs. 11%; P = 0.01). Conclusions The use of either GA or CS during EMT for patients with anterior circulation acute ELVO does not yield significantly different rates of functional independence at 3 months.

Biodiesel production from microalgae has been recognized as a promising route for sustainable energy supply. The extraction process of oil from microalgae usually generates large amount of lipid-extracted algal biomass (LEA), which has not been economically utilized until now. In order to explore economic potential of the residual biomass, LEA from extraction of microalgae strain, Nannochloropsis salina, was employed as the filler in biocomposite fabrication with poly(vinyl alcohol) (PVA). It was noted that the increase of LEA loading reduced mechanical properties, but enhanced the thermal stability of biocomposite materials compared to neat PVA. As poly(diallyldimethylammonium chloride) (PD) was incorporated, mechanical properties of PVA/LEA/PD composites were significantly improved. PD was compatible with negatively charged LEA and PVA matrix as PD possesses positive charges. PVA was compounded with 20% LEA and 12% PD to synthesize the PVA68LEA20PD12 biocomposite. In contrast to neat PVA, this biocomposite recorded the similar mechanical property but the enhanced thermal property. This type of biocomposite film can be applied in commercial industries as specialty materials, for instance, 3D printing material. This helps to improve the economic feasibility of microalgae-based biofuel production.

The optimal management of complex, Spetzler-Martin Grade 5 arteriovenous malformations (AVMs) remains a challenge, despite the availability of endovascular, surgical and radiosurgical treatment options. In cases requiring treatment due to progressive neurological deficit or recurrent hemorrhage, preoperative embolization may be an extremely useful adjunct to definitive surgical resection, and is usually accomplished via the transarterial route using liquid embolysate. However, this treatment approach often mandates access to distal arterial pedicles that can be technically challenging by standard endovascular approaches. This video describes a left parietal craniotomy for direct access microcatheterization and embolization of an otherwise endovascularly inaccessible Spetzler-Martin Grade 5 AVM prior to definitive surgical resection. The case was performed in the hybrid operative suite with biplane intraoperative angiography. Technical considerations, operative nuances and outcomes are reviewed.

Perioperative complications after transsphenoidal surgery for pituitary adenomas have been well documented in the literature; however, some complications can occur in a delayed fashion postoperatively, and reports are sparse about their occurrence, management, and outcome. Here, we describe delayed complications after transsphenoidal surgery and discuss the incidence, temporality from the surgery, and management of these complications based on the findings of studies that reported delayed postoperative epistaxis, delayed postoperative cavernous carotid pseudoaneurysm formation and rupture, vasospasm, delayed symptomatic hyponatremia, hypopituitarism, hydrocephalus, and sinonasal complications. Our findings from this review revealed an incidence of 0.6%-3.3% for delayed postoperative epistaxis at 1-3 weeks postoperatively, 18 reported cases of delayed carotid artery pseudoaneurysm formation at 2 days to 10 years postoperatively, 30 reported cases of postoperative vasospasm occurring 8 days postoperatively, a 3.6%-19.8% rate of delayed symptomatic hyponatremia at 4-7 days postoperatively, a 3.1% rate of new-onset hypopituitarism at 2 months postoperatively, and a 0.4%-5.8% rate of hydrocephalus within 2.2 months postoperatively. Sinonasal complications are commonly reported after transsphenoidal surgery, but spontaneous resolutions within 3-12 months have been reported. Although the incidence of some of these complications is low, providing preoperative counseling to patients with pituitary tumors regarding these delayed complications and proper postoperative follow-up planning is an important part of treatment planning.

Removal of excessive nutrients is essential for aquaculture wastewater treatment to protect receiving waters from eutrophication and for potential reuse of the treated water. This semi pilot-scale wastewater treatment system consists of agar-alginate algal blocks (AAAB). It was tested for removal of nutrients in shrimp farm wastewater. Aquaculture wastewater (90 days old Litopenaeus vannamei cultured water) was treated with a novel biofilter that was filled with a marine microalgae Picochlorum maculatum immobilized in alginate blocks. The removal rates of nutrients (phosphate, nitrate, nitrite and ammonia) were evaluated at each cycle for ten cycles. The results showed that the nitrite (89.6%) and ammonia (98.5%) were removed effectively while – phosphate (57%) and nitrate (46.4%) were removed less effectively.

Aneurysmal subarachnoid hemorrhage management is hampered by our incomplete understanding of what variables promote aneurysm formation, growth, and rupture. Because hypovitaminosis D has been identified as a risk factor for other vascular diseases, we examined its association with cerebral aneurysms requiring treatment.We retrospectively reviewed charts of patients with cerebral aneurysms with recorded 25-hydroxy vitamin D levels undergoing treatment at our institution from May 2010 to May 2015. We compared these patients with a group of patients without aneurysms. We used multivariable Poisson regression and backward elimination to identify factors associated with cerebral aneurysms, with a threshold P0.20. A propensity-matching algorithm was used, incorporating all factors with P0.10 in our regression model.Patients in the aneurysm group were older than those in the control group (P = 0.001) and more likely to be female (P = 0.004), to be tobacco users (P0.001), and to have a diagnosis of hypertension (P = 0.001), but ethnicity, body mass index, and diabetes rates did not differ. Vitamin D levels in the aneurysm group were lower than in the control group (23.3 ± 12.3 vs. 28.7 ± 14.1 ng/mL, P = 0.001), and the patients were more likely to be vitamin D deficient (P = 0.028). Multivariable Poisson regression demonstrated that vitamin D level, tobacco use, age, and sex were significantly associated with aneurysms requiring treatment (P0.05). The propensity-matching algorithm confirmed a significant difference in vitamin D levels between the aneurysm and control groups (P = 0.01).Patients with cerebral aneurysms requiring treatment have a significantly higher incidence of hypovitaminosis D compared with patients in a control group.

Objective No consensus exists regarding the safety and efficacy of treatment of carotid stenosis before transcatheter aortic valve replacement (TAVR). Our objective was to review our series of patients treated for carotid stenosis with stenting in the setting of severe aortic valve disease and TAVR to evaluate its safety and efficacy. Methods We reviewed patients who underwent carotid stenting in the setting of preoperative work-up or after TAVR from August 2012 through January 2015. Perioperative patient outcomes were collected to assess the safety and efficacy of carotid stenting. Results Five patients (4 men, 1 woman; median age, 83 years; range, 72–88 years) underwent successful carotid stenting before (median, 30 days before; range, 2 days–3 months) TAVR. The median extent of carotid stenosis was 80% (range, 75%–90%), but the diagnoses were incidental and all patients were asymptomatic. One patient suffered acute systolic heart failure during stenting requiring emergent balloon aortic valvuloplasty and vasopressor therapy. Median intensive care unit stay was 1 day (range, 1–16 days) for all patients, and 1 day for patients treated electively. The median hospital stay was 1 day (range, 1–16 days) for all patients, and 1 day for patients treated electively. All patients were discharged home. None suffered immediate or delayed neurological complications. Conclusions We successfully performed carotid stenting in 5 patients before TAVR for severe aortic pathology. These patients require intensive care and careful monitoring. Larger prospective studies are needed to determine whether carotid stenting in the setting of TAVR can provide long-term neurological benefits.

Turner syndrome (TS; 45,X0) is a relatively common chromosomal disorder that is associated with characteristic phenotypic stigmata: short stature, webbed neck, broad (“shield”) chest with widely spaced nipples, cubitus valgus, ovarian dysgenesis (“streak ovary”), primary amenorrhea, renal anomalies, lymphedema of the hands or feet, and various vascular abnormalities. Abnormalities of the cardiovascular system are commonly reported in patient with TS, and vascular anomalies affecting various other organ systems are also frequently reported. To date, however, few reports of intracranial vascular malformations exist. The authors report the case of a patient with TS who was found to have multiple cerebral cavernous malformations on imaging. Keywords: Cavernous angioma, Hemangioma, Cerebral cavernous malformation, Turner syndrome, Vascular malformation

Microalgae hold great promise as environmentally sustainable sources of food, animal feed, and fuel. However, large amounts of water are used during microalgae cultivation and this negatively impacts economic viability and environmental sustainability. Reusing cultivation water can reduce the direct impacts of water usage and also reduce nutrient requirements and algal wastewater treatment. However, studies have shown that algae growth in reused water can be compromised, unaffected, or sometimes enhanced compared to controls. This review examines recent studies on water reuse to qualitatively understand these varied effects. Growth inhibitors and stimulators in reused water and their underlying mechanisms are discussed, as well as recent pre-treatment technologies and factors affecting the quality of reused water, such as microalgae taxa, culture conditions, and harvesting methods, are considered. A scheme is proposed for water reuse and harvesting methods based on the desired algal end products. Taking these findings together, here we provide recommendations for further research directions as well as new insights into designing and integrating a cultivation strategy with a harvesting platform to reuse water for more efficient microalgae cultivation.

Oil recovery from microalgal cells is a crucial step in microalgal biodiesel production. Cell disruption is an essential step for lipid extraction from algal biomass. Performance of a new un-conventional disruption method for microalgae cell lysis is reported. Triiodide resin was used for cell disruption for oil recovery from microalgae liquid culture. Cell disruption efficiency depended on contact time and resin quantity along with microalgal strain characteristics. Microalgal strains with a rigid cell structure and small cell size required long contact time and more resin. Time required for cell lysis varied from 30 to 180 min. Cell disruption efficiency and oil extraction ranged from 50 to 100% and 50 to 80% respectively. Cell lysis and oil recovery were dependent largely on microalgal strains and its oil content. During cell disruption process with the triiodide resin, oil was distributed into three different phases. Water phase contained about 20% of total oil, 40–50% remained within the ruptured cells and the remaining 20–30% was adsorbed onto the resin. Triiodide resin-assisted microalgae cell lysis is a low energy process as it is operated at ambient conditions.

Most conventional processes for algal biodiesel production involve separate lipid extraction steps or require usage of dry biomass that incurs extra cost and an energy intensive drying step. A novel process that involves dehydration of wet biomass via pretreatment with ethanol followed by direct in situ transesterification into biodiesel was investigated in this study. Under mild esterification at 80 °C for 30 min, pretreating the wet biomass twice with 3 volumes of ethanol resulted in a nearly four-fold increase of fatty acid ethyl ester (FAEE) yield from 3.04 mg to 11.78 mg, while increasing the ethanol from 1 volume to 10 volumes resulted in a six fold increase of yield from 3.18 to 18.29 mg. The FAEE yield further increased when the esterification reaction was run at higher temperature and longer durations of up to 120 °C for 2 h. The overall positive impact of the pretreatment step on the final yield was far greater for milder reaction conditions, which makes the process more attractive in terms of economics and energy savings. In addition, it was found that the yield is unaffected by the choice of alcohol, which means methanol and butanol can also be used for the process. Lastly, it was found that the low concentration of water in the FAEE containing spent ethanol meant that both the solvent and sulfuric acid could be reused to further concentrate the quantity of FAEE in the final product mixture.

Algal technology has potential to combat the global energy crisis, malnutrition, and production of several value added products useful for the mankind. The cost effective cultivation system is the basis to realize this goal. Microalgal production in raceway ponds seems to be most promising, especially in the large scale. Several environmental (location of the cultivation system, rainfall, solar radiation, etc.), engineering (pond depth, CO 2 delivery system, methods of mixing, power consumption, etc.), and biological (light, pH, oxygen accumulation, salinity, Algal predators etc.) parameters affect the biomass productivity in the open pond system. Vertical mixing is an important criteria influencing the algal growth compared to axial mixing as it determines the frequency by which cell will travel from bottom (dark zone) to surface (light zone) of the open pond. Therefore, different research works on the various designs of raceway ponds were mostly focused towards enhancing the vertical mixing (e.g. Design of bend and surface geometry, engineering flow field, etc.) and CO 2 residence time (e.g. Closed, sump, airlift driven raceway ponds etc.). The present study summarizes the current state of knowledge for the biomass production in raceway ponds.

Green microalga Monoraphidium sp. was isolated during the mass cultivation study of Ettlia sp., when it was found that the culture was dominated by smaller unidentified cells with high lipid content. The strain was identified and named as Monoraphidium sp. based on its morphological characterization under light and confocal microscopy followed by genomic characterization via 18 s sequencing. The lipid content, fatty acid profiles, biomass and lipid productivity of microalga were examined under autotrophic cultivation condition using various CO 2 concentrations as well as different nitrogen sources. Isolated Monoraphidium sp. was found to have high lipid content of 28.92% determined via gas chromatography and sulfo-phospho-vanillin method (SPV). Lipid profile of the algal cells exhibited a suitable distribution of fatty acids for biodiesel production, with cultivation using urea producing particularly high quality of biodiesel. Therefore, the results suggest that Monoraphidium sp. is a promising feedstock for biodiesel production.

While the potential of hydrothermal liquefaction (HTL) of microalgae to produce biocrude regardless of the types of microalgae (biomass-agnostic) has been noted, the quality of biocrude and the Energy Return On Investment (EROI) of HTL of various microalgal species have not been compared in detail. Here we report that the quality of biocrude and the EROI of microalgal HTL are directly dependent on the lipid contents of microalgae. When Nannochloropsis oceanica (30.2% lipid content) and Golenkinia sp. (17.3% lipid content) were compared for the quality of HTL in terms of the total yield, asphaltene/non-asphaltene contents, heteroatom (O, N, and S) concentrations, and the effective hydrogen-to-carbon ratios (H/C eff ) of the biocrudes, N. oceanica with high lipid content produced biocrude that can be more suitable for catalytic upgrading to transportation fuels than the biocrude from Golenkinia sp. with low lipid content. HTL of N. oceanica at low temperature (200 °C) in particular produced the biocrude with EROI that was better than that of Golenkinia sp. These results strongly support that the choice of microalgae with high lipid content is still a key factor that must be considered for biocrude production as much as it is regarded important for biodiesel production using microalgal biomass.

Triiodide resin (TR) was used to generate axenic cultures of microalgae by employing the antibacterial capability of triiodide. A Nannochloropsis gaditana culture contaminated with bacteria was passed through a column filled with TR using the gravity flow. Based on analyses of flow cytometry and vital staining using a fluorescent dye SYTOX Green, three cycles of TR treatments remarkably reduced the number of viable bacteria but had little effects on the microalgae. This novel approach is a simple, rapid, and cost-effective method that can be used to isolate axenic cultures of microalgae.

Changes in algal and bacterial communities during thiocyanate (SCN − ) decomposition in a microalga-mediated process were studied. Pyrosequencing indicated that Thiobacillus bacteria and Micractinium algae predominated during SCN − hydrolysis, even after its complete degradation. Principal components analysis and evenness profiles (based on the Pareto–Lorenz curve) suggested that the changes in the bacterial communities were driven by nitrogen and sulfur oxidation, pH changes, and photoautotrophic conditions. The populations of predominant microalgae remained relatively stable during SCN − hydrolysis, but the proportion of bacteria – especially nitrifying bacteria – fluctuated. Thus, the initial microalgal population may be crucial in determining which microorganisms dominate when the preferred nitrogen source becomes limited. The results also demonstrated that microalgae and SCN − -hydrolyzing bacteria can coexist, that microalgae can be effectively used with these bacteria to completely treat SCN − , and that the structure of the algal-bacterial community is more stable than the community of nitrifying bacteria alone during SCN − degradation.

In this work, the effects of several factors, such as temperature, reaction time, and solvent and acid quantity on in situ transesterification yield of wet Nannochloropsis salina were investigated. Under equivalent total solvent volume to biomass ratio, pure alcohol showed higher yield compared to alcohol–chloroform solvent. For esterifying 200 mg of wet cells, 2 ml of methanol and 1 ml of ethanol was sufficient to complete in situ transesterification. Under temperatures of 105 °C or higher, 2.5% and 5% concentrations of sulfuric acid was able to successfully convert more than 90% of lipid within 30 min when methanol and ethanol was used as solvents respectively. Also, it was verified that the optimal condition found in small-scale experiments is applicable to larger scale using 2 L scale reactor as well.

An interest in biodiesel as an alternative fuel for diesel engines has been increasing because of the issue of petroleum depletion and environmental concerns related to massive carbon dioxide emissions. Researchers are strongly driven to pursue the next generation of vegetable oil-based biodiesel. Oleaginous microalgae are considered to be a promising alternative oil source. To commercialize microalgal biodiesel, cost reductions in oil extraction and downstream biodiesel conversion are stressed. Herein, starting from an investigation of oil extraction from wet microalgae, a review is conducted of transesterification using enzymes, homogeneous and heterogeneous catalysts, and yield enhancement by ultrasound, microwave, and supercritical process. In particular, there is a focus on direct transesterification as a simple and energy efficient process that omits a separate oil extraction step and utilizes wet microalgal biomass; however, it is still necessary to consider issues such as the purification of microalgal oils and upgrading of biodiesel properties.

The oleaginous microalga Nannochloropsis sp. has been spotlighted as a promising candidate in genetic engineering research for biodiesel production. However, one of the major bottlenecks in the genetic manipulation against Nannochloropsis sp. is low transformation efficiency. Based on the idea that they grow rapidly in broth culture, the effect of conditioned medium on colonization and transformation efficiency of Nannochloropsis salina was investigated. Cells grown on agar plates with 20-40% conditioned medium produced colonies that were approximately 2.3-fold larger than cells grown without conditioned medium. More importantly, the transformation efficiency was about 2-fold greater on plates with 30% conditioned medium relative to those without conditioned medium. In addition, FAME productivity in liquid cultures with 100% conditioned medium increased up to 20% compared with cultures of control medium. These results suggest that conditioned medium can be applied for efficient transformation and cost-effective cultivation of N. salina for biodiesel production.

The large water footprint is one of the major bottlenecks for the sustainable microalgae-based biorefinery. In order to reduce the amount of water that is needed for mass cultivation of microalgae, the reusability of culture medium for further algal growth was tested. Chlorella vulgaris was cultivated in recycled medium that was obtained from harvesting microalgal cells by using either centrifugation or flocculation with FeCl 3 or alum. The present study shows that centrifugation and flocculation with FeCl 3 are equally effective (> 90%) for harvesting C. vulgaris without any deleterious effects on algal growth when recycled media was used. However, even low concentration ( 3 had a positive effect on biomass and lipid productivity of C. vulgaris . Extracellular substances such as carbohydrate, proteins, or ferric ions in the recycled media appear to cause these positive effects. Furthermore, change of pH to 2–3 and washing with water were found to effectively remove the residual ferric ions that are present in either harvested biomass or biodiesel, respectively. These results suggest that the use of recycled medium for microalgal cultivation is possible, and the choice of harvest methods must be carefully made when the recycling of culture medium is considered for microalgal cultivation.

Endovascular approaches to arteriovenous malformations (AVMs) are often necessary to define and help treat these often complex lesions. Angiography provides important information to help plan surgical or radiosurgical approaches. Modern embolization techniques allow AVMs to be treated with the goals of making surgery safer and easier, eliminating high-risk features in patients with AVMs who are otherwise not candidates for treatment, and even potentially curing the patient of the lesion. Liquid embolic agents have significantly advanced what is possible with endovascular treatment of AVMs.

Transmission electron, confocal microscopy and FACS in conjunction with two different lipophilic fluorescent dyes, BODIPY 505/515 and Nile Red were used to describe the cellular development and lipid bodies formation in Aurantiochytrium sp. KRS101. TEM results revealed that multi-cellular spores were appeared in sporangium during early-exponential phase, and spores were matured in mid-exponential phase followed by release of spores from sporangium in late-exponential phase. TEM and FACS analyses proved that lipid bodies appeared, developed and degenerated in mid-exponential, early- and late-stationary phases, respectively. The staining results in FACS indicate that BODIPY 505/515 is more effective for the vital staining of intracellular lipid bodies than Nile Red. FACS based single cell sorting also showed healthy growth for BODIPY 505/515 stained cells than Nile Red stained cells. In addition, a quantitative baseline was established either for cell growth and/or lipid accumulation based on cell count, fatty acid contents/composition, and sectional/confocal images of KRS101.

Neurosurgeons have traditionally been at the forefront of investigations into clinical, translational, and basic science research to improve the quality of neurologic care. The pioneering work of Drs. Kassell and Gerk in the early versus late treatment of ruptured cerebral aneurysms (11) stands as a testament to our specialty’s long and illustrious history of critical examination of the problems of the time. However, the publication of certain randomized controlled trials (RCTs) has left the field in a more reactive posture of late. The past 12 months have provided neurosurgeons with the results of two large RCTs, ARUBA (14) and Mr. Clean (3), with the potential for diametrically different results on the field of neurosurgery. These trials demonstrated how quickly the care of neurosurgical patients can be impacted, for better or worse, in the modern age (Table 1). Although the goal of a prospective RCT is one to which we should all aspire (2), it can be difficult in many instances to ethically conduct the research “gold standard” in the face of previous large, well-conducted, experiential studies. Furthermore, the variability of disease within the central nervous system has also made some RCTs difficult to design and has produced results that have been subject to vociferous debate within the medical community. ARUBA, an RCT of medical management of brain arteriovenous malformations (bAVMs) versus surgical intervention, concluded that medical management alone was superior to intervention for the preventionofdeathorstroke(14).Theseresultshavebeentrumpeted inthemediaasthenewstandardofcareforpatientswithbAVMs.The widespreaddisseminationofthisstudymaylimitapatient’sabilityto consult with neurosurgeons, the subject matter experts on this disorder, as referring providers discount the role of any surgical intervention for these patients. Significant criticism of ARUBA’s design and execution question the validity and generalizability of the results from this trial (1, 21), but as the only National Institutes of Healthefunded RCT on bAVMs, this study’s impact may potentially carry more influence than any well-designed, new or historical, retrospective surgical series (19). Given this significant, ongoing controversy, it is evident that the final word on the best treatment for patients with bAVMs is yet to be spoken. Mr. Clean, an RCT comparing the standard-of-care medical management with or without intra-arterial treatment for largevessel anterior circulation strokes, concluded that intra-arterial treatment was superior to medical management alone (3). These findings have been supported with the reporting of additional RCTs of intra-arterial stroke treatments (5, 10). These additional studies were terminated after midterm analyses favored the intraarterial treatment arm (5, 10). In contrast to the findings from ARUBA, these results have been accepted with little to no criticism because of their well thought-out design and execution. These two examples stand in stark contrast to one another and serve to illustrate how RCTs of neurosurgical diseases performed by specialists outside of neurosurgery can significantly impact our field. As in most aspects of life, the “devil” is often found in the details of these trials. Study design and execution are critical to the validity and acceptance of any results. But regardless of the quality

This work addresses a reliable in situ transesterification process which integrates lipid extraction from wet microalgae, and its conversion to biodiesel, with a yield higher than 90 wt.%. This process enables single-step production of biodiesel from microalgae by mixing wet microalgal cells with solvent, methanol, and acid catalyst; and then heating them in one pot. The effects of reaction parameters such as reaction temperature, wet cell weight, reaction time, and catalyst volume on the conversion yield are investigated. This simultaneous extraction and transesterification of wet microalgae may enable a significant reduction in energy consumption by eliminating the drying process of algal cells and realize the economic production of biodiesel using wet microalgae.

Despite receiving increasing attention during the last few decades, the production of microalgal biofuels is not yet sufficiently cost-effective to compete with that of petroleum-based conventional fuels. Among the steps required for the production of microalgal biofuels, the harvest of the microalgal biomass and the extraction of lipids from microalgae are two of the most expensive. In this review article, we surveyed a substantial amount of previous work in microalgal harvesting and lipid extraction to highlight recent progress in these areas. We also discuss new developments in the biodiesel conversion technology due to the importance of the connectivity of this step with the lipid extraction process. Furthermore, we propose possible future directions for technological or process improvements that will directly affect the final production costs of microalgal biomass-based biofuels.

Semiconductor tin oxide (SnO 2 ) nanotubes have been synthesised in bulk quantities using a sol–gel template (AAO membrane) synthetic technique. The morphology and crystal structure of SnO 2 nanotubes were characterised by a field emission scanning electron microscope (FESEM) and a transmission electron microscope (TEM). The as-prepared SnO 2 nanotubes are polycrystalline with an outer diameter of 200 nm, an inner diameter of about 150 nm and a length extending to tens of micrometers. SnO 2 nanotube sensors exhibited high sensitivity towards ethanol gas.

Incision techniques in the past focused on fixing the pretarsal skin to either the tarsal plate or to the levator aponeurosis. High relapse rate remains one of the main concerns in double-eyelid surgery. To address these issues, the author developed a pretarsal orbicularis oculi muscle-levator aponeurosis fixation technique. This technique results in better fixation between the skin and the levator aponeurosis by recruiting a bulky, pretarsal orbicularis oculi muscle in the fixation mechanism. This technique provides for a solidly fixed, tightly stretched pretarsal skin when the eyes are open with significantly reduced chances of relapse.