Risk assessment of early therapeutic anticoagulation following cranial surgery: an institutional case series.

OBJECTIVE: Postoperative thrombotic complications represent a unique challenge in cranial neurosurgery as primary treatment involves therapeutic anticoagulation. The decision to initiate therapy and its timing is nuanced, as surgeons must balance the risk of catastrophic intracranial hemorrhage (ICH). With limited existing evidence to guide management, current practice patterns are subjective and inconsistent. The authors assessed their experience with early therapeutic anticoagulation (≤ 7 days postoperatively) initiation for thrombotic complications in neurosurgical patients undergoing cranial surgery to better understand the risks of catastrophic ICH. METHODS: Adult patients treated with early therapeutic anticoagulation following cranial surgery were considered. Anticoagulation indications were restricted to thrombotic or thromboembolic complications. Records were retrospectively reviewed for demographics, surgical details, and anticoagulation therapy start. The primary outcome was the incidence of catastrophic ICH, defined as ICH resulting in reoperation or death within 30 days of anticoagulation initiation. As a secondary outcome, post-anticoagulation cranial imaging was reviewed for new or worsening acute blood products. Fisher's exact and Wilcoxon rank-sum tests were used to compare cohorts. Cumulative outcome analyses were performed for primary and secondary outcomes according to anticoagulation start time. RESULTS: Seventy-one patients satisfied the inclusion criteria. Anticoagulation commenced on mean postoperative day (POD) 4.3 (SD 2.2). Catastrophic ICH was observed in 7 patients (9.9%) and was associated with earlier anticoagulation initiation (p = 0.02). Of patients with catastrophic ICH, 6 (85.7%) had intra-axial exploration during their index surgery. Patients with intra-axial exploration were more likely to experience a catastrophic ICH postoperatively compared to those with extra-axial exploration alone (OR 8.5, p = 0.04). Of the 58 patients with postoperative imaging, 15 (25.9%) experienced new or worsening blood products. Catastrophic ICH was 9 times more likely with anticoagulation initiation within 48 hours of surgery (OR 8.9, p = 0.01). The cumulative catastrophic ICH risk decreased with delay in initiation of anticoagulation, from 21.1% on POD 2 to 9.9% on POD 7. Concurrent antiplatelet medication was not associated with either outcome measure. CONCLUSIONS: The incidence of catastrophic ICH was significantly increased when anticoagulation was initiated within 48 hours of cranial surgery. Patients undergoing intra-axial exploration during their index surgery were at higher risk of a catastrophic ICH.

ARISE I Consensus Statement on the Management of Chronic Subdural Hematoma.

ARISE (Aneurysm/AVM/cSDH Roundtable Discussion With Industry and Stroke Experts) organized a one-and-a-half day meeting and workshop and brought together representatives from academia, industry, and government to discuss the most promising approaches to improve outcomes for patients with chronic subdural hematoma (cSDH). The emerging role of middle meningeal artery embolization in clinical practice and the design of current and potential future trials were the primary focuses of discussion. Existing evidence for imaging, indications, agents, and techniques was reviewed, and areas of priority for study and key questions surrounding the development of new and existing treatments for cSDH were identified. Multiple randomized, controlled trials have met their primary efficacy end points, providing high-level evidence that middle meningeal artery embolization is a potent adjunctive therapy to the standard (surgical and nonsurgical) management of neurologically stable cSDH patients in terms of reducing rates of disease recurrence. Pooled data analyses following the formal conclusion and publication of these trials will form a robust foundation upon which guidelines can be strengthened for cSDH treatment modalities and optimal patient selection, as well as delineate future lines of investigation.

Treatment outcomes for ARUBA-eligible brain arteriovenous malformations: a comparison of real-world data from the NVQI-QOD AVM registry with the ARUBA trial.

BACKGROUND: Significant controversy exists about the management of unruptured cerebral arteriovenous malformations (AVMs). Results from A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) suggested that intervention increases the risk of stroke/death compared with medical management. However, numerous study limitations raised concerns about the trial's generalizability. OBJECTIVE: To assess the rate of stroke/death and functional outcomes in ARUBA-eligible patients from a multicenter database, the Neurovascular Quality Initiative-Quality Outcomes Database (NVQI-QOD). METHODS: We performed a retrospective analysis of prospectively collected data of ARUBA-eligible patients who underwent intervention at 18 participating centers. The primary endpoint was stroke/death from any cause. Secondary endpoints included neurologic, systemic, radiographic, and functional outcomes. RESULTS: 173 ARUBA-eligible patients underwent intervention with median follow-up of 269 (25-722.5) days. Seventy-five patients received microsurgery±embolization, 37 received radiosurgery, and 61 received embolization. Baseline demographics, risk factors, and general AVM characteristics were similar between groups. A total of 15 (8.7%) patients experienced stroke/death with no significant difference in primary outcome between treatment modalities. Microsurgery±embolization was more likely to achieve AVM obliteration (P<0.001). Kaplan-Meier survival curves demonstrated no difference in overall death/stroke outcomes between the different treatment modalities' 5-year period (P=0.087). Additionally, when compared with the ARUBA interventional arm, our patients were significantly less likely to experience death/stroke (8.7% vs 30.7%; P<0.001) and functional impairment (mRS score ≥2 25.4% vs 46.2%; P<0.01). CONCLUSION: Our results suggest that intervention for unruptured brain AVMs at comprehensive stroke centers across the United States is safe.

Diagnostic yield of cerebral angiography for intracranial hemorrhage in young patients: A single-center retrospective analysis.

BACKGROUND: Intracranial hemorrhage (ICH) secondary to hypertension (HTN) classically occurs in the basal ganglia, cerebellum, or pons. Vascular lesions such as aneurysms or arteriovenous malformations (AVMs) are more common in younger patients. We investigated the utility of diagnostic subtraction angiography (DSA) in young hypertensive patients with non-lobar ICH. METHODS: A retrospective review (2013-2022) identified young (18-60 years) patients who underwent DSA for ICH. HTN history, ICH location, presence/absence of subarachnoid hemorrhage (SAH), and computed tomography angiography (CTA) findings were collected. The main outcome was DSA-positivity, defined as presence of an AVM, aneurysm, Moyamoya disease, reversible cerebral vasoconstriction syndrome, or dural arteriovenous fistula on DSA. RESULTS: Two hundred sixty patients were included, and the DSA-positivity rate was 19%.DSA-positivity was lower in hypertensive patients with ICHs in the cerebellum, pons, or basal ganglia compared to the rest of the patient sample (9% vs 26%, p = 0.0002, Fisher's exact test). We developed the ICH-Angio score (0-5 points) based on CTA findings, ICH location, HTN history, and presence of SAH to predict risk of underlying vascular lesions. DSA-positivity was lower in those with a score of 0 (0/62; 0%) compared to a score of 1 (5/52; 10%), 2 (17/48; 35%), 3 (10/20; 50%), 4 (5/6; 83%), or 5 (3/3; 100%). CONCLUSION: The ICH-Angio score was able to non-invasively rule out an underlying vascular etiology for ICH in up to one-third of patients. HTN, ICH location, CTA findings, and associated SAH can identify patients at low risk for harboring underlying vascular lesions.

Endovascular Management of Arteriovenous Malformation-Associated Intracranial Aneurysms: A Systematic Literature Review.

OBJECTIVE: Intracranial aneurysms are present in up to 18% of arteriovenous malformations (AVMs) and increase the risk of intracranial hemorrhage. No consensus exists on the optimal treatment strategy for AVM-associated aneurysms. The goal of this study was to systematically review endovascular treatment methods of AVM-associated intracranial aneurysms, radiographic outcomes, and periprocedural complications. METHODS: A systematic review was performed in accordance with PRISMA guidelines to identify studies that investigated the use of endovascular treatments for management of patients with AVM-associated aneurysms. Collected variables included aneurysm and AVM location, aneurysm size and characteristics, AVM and aneurysm treatment modality, periprocedural complications, and long-term clinical and radiographic outcomes. RESULTS: Eight studies with 237 patients and 314 AVM-associated intracranial aneurysms were included. Two-hundred and twenty-four aneurysms were flow-related (71.3%), 80 were intranidal (25.5%), and 10 were unrelated (3.2%). Complete occlusion was 56.3% (18/32) for aneurysmal coil embolization and 99% (104/105) for parent vessel sacrifice. Of the 13 aneurysms treated with ethanol sclerotherapy, 8 were successfully obliterated (8/13; 61%) using ethanol sclerotherapy alone and the rest required adjunct endovascular embolization for obliteration of the artery and associated aneurysm. The periprocedural complication rate was approximately 12% and consisted of ischemic symptoms, intracranial hemorrhage, and coiling complications. CONCLUSIONS: Endovascular management options of AVM-associated intracranial aneurysms are limited and mostly comprised primary aneurysmal coil embolization or parent vessel sacrifice using coils or liquid embolics. Embolization strategy depends on factors such as AVM angioarchitecture, rupture status, and adjunct AVM treatments.

Early post-Humanitarian Device Exemption experience with the Neuroform Atlas stent.

INTRODUCTION: The low-profile Neuroform Atlas stent received FDA Humanitarian Device Exemption status (HDE) in January 2018 for stent-assisted coil embolization of wide-necked saccular aneurysms. We review and report our results with the Atlas stent in our institution within the first year after its HDE approval. METHODS: Our retrospective chart review identified patients treated with the Atlas stent. We analyzed the patient demographics, aneurysm characteristics, stent parameters and configuration, complications, angiographic, and clinical outcomes at discharge. RESULTS: From January to December 2018, 76 Atlas stents were deployed in 58 patients (average 1.3 stents/patient). Median patient age was 63.5 (IQR 56-71) years. Fifty-six (96.6%) patients had elective embolization of unruptured aneurysms, while two (3.4%) patients underwent embolization of a ruptured aneurysm within 2 weeks of subarachnoid hemorrhage. Forty (69.0%) patients were treated with a single stent, 15 (25.9%) with a Y-stent, and three (5.2%) with X-stent configuration. All stent deployments were technically successful. Most stents (82.9%) were the smallest 3 mm diameter devices. Procedural complications included transient stent-associated thrombosis in three (5.2%) patients and aneurysm rupture in one (1.7%). None had distal embolization, associated cerebral infarction, or permanent neurological deficits. Immediate Raymond-Roy 1 occlusion was achieved in 41 (70.7%) patients. Median hospital length of stay for elective aneurysm embolization was 1 day. Excellent outcomes with median National Institute of Health Stroke Scale score 0 (IQR 0-0) and modified Rankin Score 0 (IQR 0-1) were seen for elective patients at discharge. CONCLUSION: The Neuroform Atlas stent provided a reliable technical and safety profile for the treatment of intracranial wide-neck aneurysms. Further experience is needed to determine long-term durability and safety of this device.

Carotid Endarterectomy and Carotid Artery Stenting in a Predominantly Symptomatic Real-World Patient Population.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are well-established treatments that have been shown to decrease stroke recurrence in patients with underlying carotid artery disease. We assessed clinical outcome, safety, and restenosis rates for patients who underwent standardized CEA or CAS at our tertiary care center using patient selection criteria based on available scientific evidence. METHODS: Retrospective chart review of patients who underwent CEA or CAS between 2009 and 2016. RESULTS: In total, 314 cases (204 with CEA and 110 with CAS) were analyzed. Patients were predominantly white (84.4%), men (61.1%) with hypertension (86.9%) and hyperlipidemia (81.8%). Most patients (84.5%) had symptomatic carotid disease. No significant differences were observed in median postoperative National Institutes of Health Stroke Scale and modified Rankin scale (mRS) scores based on pretreatment symptomatic status or treatment modality (CEA vs. CAS). Most patients (85.9%) had favorable outcomes (mRS score 0-2) at a median follow-up of 11.7 months (interquartile range, 1.8-28.8). The perioperative complication rate was low (3.2%), and permanent neurologic deficit was seen in only 3 patients (1%). Restenosis was found in 7.3%, without significant difference between CEA and CAS at last follow-up. Restenosis was asymptomatic in most patients. CONCLUSIONS: Our findings in a real-world predominantly symptomatic cohort demonstrate that favorable patient outcomes and low restenosis and complication rates can be achieved with both CEA and CAS by the utilization of a consistent institutional patient selection and treatment process.

Early versus Delayed Extracranial-Intracranial Bypass Surgery in Symptomatic Atherosclerotic Occlusion.

BACKGROUND: Clinical trials of extracranial-intracranial (EC-IC) bypass surgery studied patients in subacute and chronic stage after ischemic event. OBJECTIVE: To investigate the short-term outcomes of EC-IC bypass in progressive acute ischemic stroke or recent transient ischemic attacks. METHODS: The study was a retrospective review at a single tertiary referral center from 2008 to 2015. Inclusion criteria consisted of EC-IC bypass within 1 yr of last ischemic symptoms ipsilateral to atherosclerotic occlusion of internal carotid or middle cerebral artery. Early bypass group who underwent surgery within 7 d of last ischemic symptoms were compared to late bypass group who underwent surgery >7 d from last ischemic symptom. The primary endpoint was perioperative ischemic or hemorrhagic stroke or intracranial hemorrhage within 7 d of surgery. RESULTS: Of 126 patients who underwent EC-IC bypass during the period, 81 patients met inclusion criteria, 69 (85%) persons had carotid artery occlusion, 7 (9%) had proximal MCA occlusion, and 5 (6%) had both. Early surgery had a 31% (9/29) perioperative stroke rate compared to 11.5% (6/52) of patients undergoing late bypass (P = .04). Of patients with acute stroke within 7 d of surgery, 41% (7/17) had perioperative stroke within 7 d (P = .07). Six of nine patients (67%) with blood pressure dependent fluctuation of neurologic symptoms had perioperative stroke (P = .049). CONCLUSION: EC-IC bypass in setting of acute symptomatic stroke within 1 wk may confer higher risk of perioperative stroke. Patients undergoing expedited or urgent bypass for unstable or fluctuating stroke symptoms might be at highest risk for perioperative stroke.

A Tribute to Dr Robert J. White.

Robert J. White is probably best known as the first neurosurgeon to perform successful "cephalic exchange" on monkeys in 1971. However, he was also a pioneer in the field of neurosurgery and contributed tremendously to the field of neuroanesthesia and bioethics. White received medical training at the University of Minnesota, Harvard University, Peter Bent Brigham Hospital, and Mayo Clinic before becoming the first Chief of Neurosurgery at Metrohealth Hospital in Cleveland, Ohio. He made significant strides in the field of spinal cord cooling and hypothermia. White and his team was also the first to successfully isolate the monkey brain with retention of biological activity. In 2004 and 2006, White and colleagues were nominated for the Nobel Prize in Physiology and Medicine, with Harvey Cushing and Wilder Penfield being the only other 2 neurosurgeons ever to be nominated for the award. Aside from his career as a neurosurgeon, he was also an advisor to 2 popes and an advocate for animal research. By the end of his career, White performed over 10 000 brain operations and published over 1000 articles, which has pushed the frontiers of neurosurgical research.

Treatment of an Anterior Inferior Cerebellar Artery Aneurysm With Microsurgical Trapping and In Situ Posterior Inferior Cerebellar Artery to Anterior Inferior Cerebellar Artery Bypass: Case Report.

BACKGROUND: Anterior inferior cerebellar artery (AICA) aneurysms are rare lesions whose treatment can involve microsurgical and/or endovascular techniques. Such treatment can be challenging and may carry a significant risk of neurological morbidity. OBJECTIVE: To demonstrate a case involving a complex AICA aneurysm that was treated with a unique microsurgical approach involving trapping the aneurysm and performing in Situ bypass from the posterior inferior cerebellar artery (PICA) to the distal AICA. The nuances of AICA aneurysms and revascularization strategies are discussed. METHODS: The aneurysm and the distal segments of AICA and PICA were exposed with a retrosigmoid and far lateral approach. A side-to-side anastomosis was performed between the adjacent caudal loops of PICA and AICA. The AICA aneurysm was then treated by trapping the aneurysm-bearing segment of the parent vessel between 2 clips. RESULTS: A postoperative angiogram demonstrated a patent PICA-AICA bypass and complete occlusion of the AICA aneurysm. There were no complications, and the patient made an excellent recovery. CONCLUSION: The combination of parent vessel sacrifice and bypass remains an excellent option for certain difficult-to-treat aneurysms. This case involving PICA-AICA bypass to treat an AICA aneurysm serves as an example of the neurosurgeon's ability to develop unique solutions that take advantage of individual anatomy.

BrainPath-Mediated Resection of a Ruptured Subcortical Arteriovenous Malformation.

BACKGROUND: Although tubular retractor systems have gained popularity for other indications, there have been few reports of their use for arteriovenous malformation (AVM) surgery. A patient was diagnosed with a ruptured 1.2-cm subcortical AVM after presenting with intracerebral hemorrhage in the right frontal lobe and anterior basal ganglia. The characteristics of this AVM made it amenable to resection using a tubular retractor. OBJECTIVE: To demonstrate the feasibility and safety of AVM resection using a tubular retractor system. METHODS: Resection of the ruptured 1.2-cm subcortical AVM was performed utilizing the BrainPathTM (NICO corp, Indianapolis, Indiana) tubular retractor system. RESULTS: The BrainPathTM approach provided sufficient visualization and surgical freedom to permit successful AVM resection and hematoma evacuation. Postoperative imaging demonstrated near total hematoma removal and angiographic obliteration of the AVM. There were no complications, and the patient made an excellent recovery. CONCLUSION: Tubular retractors warrant consideration for accessing small, deep, ruptured AVMs. The nuances of such systems and their role in AVM surgery are discussed.

Treatment Outcomes of A Randomized Trial of Unruptured Brain Arteriovenous Malformation-Eligible Unruptured Brain Arteriovenous Malformation Patients.

BACKGROUND: The guideline for treating unruptured brain arteriovenous malformations (ubAVMs) remains controversial. A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) reported lower risk of stroke or death with conservative management compared to interventional treatment. There were numerous limitations to the study, including short follow-up period and disproportionate number of patients treated with surgery and embolization. OBJECTIVE: To evaluate whether treatment of ARUBA-eligible patients have acceptable outcomes at our institution. METHODS: Retrospective analysis was performed on 673 patients with brain AVMs treated at our institution between 2001 and 2014. One hundred five patients were ARUBA eligible and included in the study. Patients were divided into the microsurgery or Gamma Knife Radiosurgery (GKS; Elekta, Stockholm, Sweden) arm depending on their final treatment. Mean follow-up period was 43 mo (range 4-136 mo). Primary outcome was stroke or death. RESULTS: A total of 8 (7.6%) patients had a stroke or died. The overall risk of stroke or death was 11.4% (5 of 44 patients) for the microsurgery arm and 4.9% (3 of 61 patients) for the GKS arm. The annual rates of stroke or death were 2.1%, 4.0%, and 1.2% for the entire patient cohort, microsurgery arm, and GKS arm, respectively. AVM obliteration rates at the end of the follow-up period were 95.5% and 47.5% for the microsurgery and GKS arms, respectively. CONCLUSION: We report a lower overall risk of stroke or death in our ARUBA-eligible patients following treatment than ARUBA. Our results suggest that microsurgery and GKS may be appropriate treatments for patients with ubAVM.

Initial Single-Center Technical Experience With the BrainPath System for Acute Intracerebral Hemorrhage Evacuation.

BACKGROUND: Surgical intervention has been proposed as a means of reducing the high morbidity and mortality associated with acute intracerebral hemorrhage (ICH), but many previously reported studies have failed to show a clinically significant benefit. Newer, minimally invasive approaches have shown some promise. OBJECTIVE: We report our early single-center technical experience with minimally invasive clot evacuation using the BrainPath system. METHODS: Prospective data were collected on patients who underwent ICH evacuation with BrainPath at the Cleveland Clinic from August 2013 to May 2015. RESULTS: Eighteen patients underwent BrainPath evacuation of ICH at our center. Mean ICH volume was 52.7 mL ± 22.9 mL, which decreased to 2.2 mL ± 3.6 mL postevacuation, resulting in a mean volume reduction of 95.7% ± 5.8% (range 0-14 mL, P < .001). In 65% of patients, a bleeding source was identified and treated. There were no hemorrhagic recurrences during the hospital stay. In this cohort, only 1 patient (5.6%) died in the first 30 days of follow-up. Median Glasgow Coma Score improved from 10 (interquartile range 5.75-12) preoperation to 14 (interquartile range 9-14.25) postoperation. Clinical follow-up in this cohort is ongoing. CONCLUSION: Evacuation of ICH using the BrainPath system is safe and technically effective. The volume of clot removed compares favorably with other published studies. Early improved clinical outcomes are suggested by improvement in Glasgow Coma Score and reduced 30-day mortality. Ongoing analysis is necessary to elucidate long-term clinical outcomes and the subsets of patients who are most likely to benefit from surgery.

Microsurgical Repair of Ruptured Aneurysms Associated with Moyamoya-Pattern Collateral Vessels of the Middle Cerebral Artery: A Report of Two Cases.

BACKGROUND: Patients with Moyamoya or other intracranial steno-occlusive disease are at risk for developing aneurysms associated with flow through collateral vessels. Because these lesions are rare, the optimal management remains unclear. Here, we describe 2 cases of microsurgical repair of ruptured collateral vessel aneurysms associated with middle cerebral artery (MCA) occlusion. CASE DESCRIPTION: The first patient was a 61-year-old man who presented with right frontal and intraventricular hemorrhage. Angiography revealed chronic right M1 occlusion and a 3-mm spherical lenticulostriate aneurysm. The frontal lobe hematoma was evacuated to reveal the aneurysm, which was safely cauterized and resected by coagulating and dividing the lenticulostriate parent vessel. The procedure was carried out with neuronavigation guidance and intraoperative neuromonitoring. The patient was discharged with no neurologic deficits. The second patient was a 53-year-old woman who presented with subarachnoid and intracerebral hemorrhage. Computed tomography angiogram showed a 2-mm saccular MCA aneurysm. Emergency left decompressive hemicraniectomy and hematoma evacuation were performed. The aneurysm, arising from a small collateral type vessel, was safely clipped without complications. Postoperative angiography revealed absence of the superior MCA trunk with a dense network of collateral vessels at the site of the clipped aneurysm. The patient recovered well and was ambulating independently 6 months postoperatively. No rebleeding occurred in the 2 patients. CONCLUSIONS: Our experience suggests that patients with MCA occlusion can harbor associated aneurysms related to flow through collateral vessels and can present with hemorrhage. Microsurgical repair of these aneurysms can be performed safely to prevent rebleeding.

Long-Term Effect of Flow Diversion on Large and Giant Aneurysms: MRI-DSA Clinical Correlation Study.

BACKGROUND: The long-term effect of flow diversion (FD) on aneurysms has not been well studied. OBJECTIVE: We aimed to assess the effect of the Pipeline embolization device (Covidien, Irvine, California, USA) on large and giant intracranial aneurysms with magnetic resonance imaging (MRI) and digital subtraction angiography (DSA) and then correlate with clinical follow-up. METHODS: We conducted a retrospective analysis of aneurysms treated solely with Pipeline without adjunctive therapy. The largest aneurysm diameters were compared with pretreatment and post treatment MRI and correlated with DSA and clinical symptoms. RESULTS: Twelve patients harboring large and giant saccular unruptured aneurysms, treated with Pipeline, were included. Mean follow-up times were as follows: MRI 22.8 months (range 1-57), DSA 18.2 months (range 1-33), and clinical 29 months (range 1-48). Ten (83%) of 12 treated aneurysms decreased in size on MRI, which was first seen at an average of 17 months (range 4-57). In 70% of patients the change was noted on MRI ≤1 year after treatment, at an average of 9.1 months (range 4-12). MRI reduction was more likely in angiographically occluded aneurysms. Five aneurysms with complete occlusion on early angiogram showed size reduction on MRI only at ≥12 months. Mean aneurysm size reduction was 57% (range 19.6-94.2), which correlated well with improvement of cranial neuropathies in 75% and headaches in 100% of patients. CONCLUSION: Most aneurysms treated with Pipeline decreased in size, correlating with clinical improvement. Some aneurysms remained unchanged on MRI until a later time point despite early DSA occlusion. It may be reasonable to eliminate early postprocedural imaging and start follow-up only as late as 1 year after FD treatment in clinically stable, asymptomatic patients.

Long-term Follow-up of In-stent Stenosis After Pipeline Flow Diversion Treatment of Intracranial Aneurysms.

BACKGROUND: There is scant information on in-stent stenosis after flow diversion treatment of intracranial aneurysms with the Pipeline Embolization Device (PED). OBJECTIVE: To assess the incidence, severity, nature, and clinical consequences of in-stent stenosis on angiographic follow-up after treatment with the PED. METHODS: A retrospective study of patients who underwent aneurysm treatment with the PED was conducted. In-stent stenosis was assessed on subsequent follow-up angiography. Intimal hyperplasia was defined as a uniform growth process beyond the limits of the metallic mesh at <25%. In-stent stenosis represented an area of parent vessel narrowing, most often focal, graded as mild (25%-50%), moderate (50%-75%), or severe (>75%). RESULTS: Between June 2011 and April 2015, 80 patients were treated with the PED. Angiographic follow-up was available for 51 patients (representing 76% of available or 64% of all patients). Mean follow-up was 12.5 months. In-stent stenosis was detected in 5 patients (9.8%) at a median of 6 months. Stenosis was mild in 4 of 5 (80%) and moderate in 1 of 5 (20%) patients. There were no cases of severe stenosis. No stenosis caused flow limitation, clinical symptoms, or required re-treatment. Additional follow-up angiography was available in 2 of 5 stenosis patients showing marked improvement. Sixteen patients (31%) had intimal hyperplasia, and 28 patients (55%) had no stenosis. Asymptomatic stent occlusion occurred in 2 patients (4%) related to medication noncompliance. CONCLUSION: Treatment with the PED was associated with a 9.8% rate of in-stent stenosis, detected on first angiographic follow-up, at a median of 6 months. None were symptomatic or required re-treatment, and they showed significant improvement on follow-up. ABBREVIATION: FD, flow diverter.

Physical characteristics of catheters used for subarachnoid drainage.

BACKGROUND: Cerebrospinal fluid diversion through lumbar drainage catheters is a routine procedure that is used in a variety of clinical applications. Fracture of catheters during insertion or removal may result in retained foreign bodies that may lead to patient morbidity with potential legal ramifications. Fracture resistance is an important component of drain selection. OBJECTIVE: To analyze catheter integrity to determine which commercially available catheters are most robust and resistant to fracture. METHODS: Physical properties of the commercially available drainage catheters that can be advanced through a Touhy needle were assessed using laboratory equipment and reported. Five types of catheter were analyzed for break load, tensile strength, extension at break, and shear strength. RESULTS AND CONCLUSIONS: Of the five types of catheter, the Arrow catheter showed the greatest resistance to fracture. Of the drainage catheters, the Codman catheter showed the greatest resistance to fracture.

Chronic Cerebral Ischemia: Where "Evidence-Based Medicine" Fails Patients.

BACKGROUND AND IMPORTANCE: The publication of the COSS (Carotid Occlusion Surgery Study) trial in 2011 concluded that the addition of external carotid to internal carotid (EC-IC) bypass to a medical regimen "did not reduce the risk of ipsilateral ischemic stroke at 2 years" for patients with symptomatic internal carotid artery occlusion. This has resulted in decreasing referrals for surgical management under the guise of "evidence-based" medicine. The conclusions drawn from a study can only be as good as the selected end points. COSS did not consider important end points such as the effects of long-term cerebral ischemia or recurrent debilitating transient ischemic attacks (TIAs). However, the study is often quoted as "proof" that EC-IC bypass has no role in the treatment of these patients. CLINICAL PRESENTATION: A middle-aged patient presented to a primary neurologist with left-sided weakness and 2 months of personality changes. Magnetic resonance imaging (MRI) showed small watershed infarcts in the right hemisphere. An angiogram showed right carotid occlusion. Perfusion scans confirmed hypoperfusion. The patient was managed medically. Without any further clinical stroke events, the patient progressed to complete hemispheric infarction on MRI over the next 5 months. CONCLUSION: The public perception of the results of large randomized clinical trials is significantly altered by their ubiquitous dissemination and broad generalization without adequate understanding of the details. Careful assessment of the methodology and end points of a trial are essential when applying the results for evidence-based medicine to individual patients. This patient would have been considered a medical "success" in COSS, but her outcome with surgical intervention will never be known.