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OBJECTIVE The Pipeline Embolization Device (PED) has prompted a paradigm shift in the approach to posterior circulation aneurysms. The year 2021 marks a decade since FDA approval of this flow diverter, and during this time operators have adapted to its off-label uses. The authors examined whether case selection, practice trends, and patient outcomes have changed over this 10-year period. METHODS This study is a retrospective review of consecutive posterior circulation aneurysms managed with the PED at four academic institutions in the US between January 1, 2011, and January 1, 2021. Factors related to case selection, rates of aneurysm occlusion, or complications were identified and evaluated. Angiographic outcomes as well as thromboembolic and hemorrhagic complications were investigated. RESULTS This study included 117 patients (median age 60 years). At a median follow-up of 12 months, adequate occlusion (> 90%) was attained in 73.2% of aneurysms. Aneurysm occlusion rates were similar over the study interval. Thromboembolic and hemorrhagic complications were reported in 12.0% and 6.0% of the procedures, respectively. There was a nonsignificant trend toward a decline in the rate of thromboembolic (14.1% in 2011–2015 vs 9.4% in 2016–2021, p = 0.443) and hemorrhagic (9.4% in 2011–2015 vs 1.9% in 2016–2021, p = 0.089) complications. CONCLUSIONS The authors observed a trend toward a decline in the rate of thromboembolic and hemorrhagic complications with improved operator experience in using the PED for posterior circulation aneurysms. The use of single-device PED flow diversion significantly increased, as did the tendency to treat smaller aneurysms and observe large unruptured fusiform/dolichoectatic lesions. These findings reflect changes attributable to evolving judgment with maturing experience in PED use.

OBJECTIVE Frailty is one of the important factors in predicting the outcomes of surgery. Many surgical specialties have adopted a frailty assessment in the preoperative period for prognostication; however, there are limited data on the effects of frailty on the outcomes of cerebral aneurysms. The object of this study was to find the effect of frailty on the surgical outcomes of anterior circulation unruptured intracranial aneurysms (UIAs) and compare the frailty index with other comorbidity indexes. METHODS A retrospective study was performed utilizing the National Inpatient Sample (NIS) database (2016–2018). The Hospital Frailty Risk Score (HFRS) was used to assess frailty. On the basis of the HFRS, the whole cohort was divided into low-risk (0–5), intermediate-risk (> 5 to 15), and high-risk (> 15) frailty groups. The analyzed outcomes were nonhome discharge, complication rate, extended length of stay, and in-hospital mortality. RESULTS In total, 37,685 patients were included in the analysis, 5820 of whom had undergone open surgical clipping and 31,865 of whom had undergone endovascular management. Mean age was higher in the high-risk frailty group than in the low-risk group for both clipping (63 vs 55.4 years) and coiling (64.6 vs 57.9 years). The complication rate for open surgical clipping in the high-risk frailty group was 56.1% compared to 0.8% in the low-risk group. Similarly, for endovascular management, the complication rate was 60.6% in the high-risk group compared to 0.3% in the low-risk group. Nonhome discharges were more common in the high-risk group than in the low-risk group for both open clipping (87.8% vs 19.7%) and endovascular management (73.1% vs 4.4%). Mean hospital charges for clipping were $341,379 in the high-risk group compared to $116,892 in the low-risk group. Mean hospital charges for coiling were $392,861 in the high-risk frailty group and $125,336 in the low-risk group. Extended length of stay occurred more frequently in the high-risk frailty group than in the low-risk group for both clipping (82.9% vs 10.7%) and coiling (94.2% vs 12.7%). Frailty had higher area under the receiver operating characteristic curve values than those for other comorbidity indexes and age in predicting outcomes. CONCLUSIONS Frailty affects surgical outcomes significantly and outperforms age and other comorbidity indexes in predicting outcome. It is imperative to include frailty assessment in preoperative planning.

Background The Woven EndoBridge (WEB) device was explicitly designed for wide-neck intracranial bifurcation aneurysms. Small-scale reports have evaluated the off-label use of WEB devices for the treatment of sidewall aneurysms, with promising outcomes. Purpose To compare the angiographic and clinical outcomes of the WEB device for the treatment of sidewall aneurysms compared with the treatment of bifurcation aneurysms. Materials and Methods A retrospective review of the WorldWideWEB Consortium, a synthesis of retrospective databases spanning from January 2011 to June 2021 at 22 academic institutions in North America, South America, and Europe, was performed to identify patients with intracranial aneurysms treated with the WEB device. Characteristics and outcomes were compared between bifurcation and sidewall aneurysms. Propensity score matching (PSM) was used to match by age, pretreatment ordinal modified Rankin Scale score, ruptured aneurysms, location of aneurysm, multiple aneurysms, prior treatment, neck, height, dome width, daughter sac, and incorporated branch. Results A total of 683 intracranial aneurysms were treated using the WEB device in 671 patients (median age, 61 years [IQR, 53-68 years]; male-to-female ratio, 1:2.5). Of those, 572 were bifurcation aneurysms and 111 were sidewall aneurysms. PSM was performed, resulting in 91 bifurcation and sidewall aneurysms pairs. No significant difference was observed in occlusion status at last follow-up, deployment success, or complication rates between the two groups. Conclusion No significantly different outcomes were observed following the off-label use of the Woven EndoBridge, or WEB, device for treatment of sidewall aneurysms compared with bifurcation aneurysms. The correct characterization of the sidewall aneurysm location, neck angle, and size is crucial for successful treatment and lower retreatment rate. © RSNA, 2022 See also the editorial by Hetts in this issue.

Background Open surgery has traditionally been preferred for the management of bifurcation middle cerebral artery (MCA) aneurysms. Flow diverting stents present a novel endovascular strategy for aneurysm treatment. Objective To add to the limited literature describing the outcomes and complications in the use of flow diverters for the treatment of these complex aneurysms. Methods This is a multicenter retrospective review of MCA bifurcation aneurysms undergoing flow diversion. We assessed post-treatment radiological outcomes and both thromboembolic and hemorrhagic complications. Results We reviewed the outcomes of 54 aneurysms treated with flow diversion. Four (7.4%) of the aneurysms had a history of rupture (3 remote and 1 acute). Fourteen (25.9%) of the aneurysms already underwent either open surgery or coiling prior to flow diversion. A total of 36 out of the 45 aneurysms (80%) with available follow-up data had adequate aneurysm occlusion with a median follow-up time of 12 mo. There were no hemorrhagic complications but 16.7% (9/54) had thromboembolic complications. Conclusion Flow diverting stents may be a viable option for the endovascular treatment of complex bifurcation MCA aneurysms. However, compared to published series on the open surgical treatment of this subset of aneurysms, flow diversion has inferior outcomes and are associated with a higher rate of complications.

Several studies have shown promising outcomes of the Woven EndoBridge (WEB) device for the treatment of wide-necked intracranial bifurcation aneurysms. This is a multicenter study attempts to explore the changes in trends and treatment outcomes over time for WEB embolization of intracranial aneurysms. The WorldWideWEB consortium is a retrospective multicenter collaboration of data from international centers spanning from January 2011 and June 2021, with no limitations on aneurysm location or rupture status. Both bifurcation and sidewall aneurysms were included. These patients were stratified based on treatment year into five treatment intervals: 2011-2015 (N = 66), 2016-2017 (N = 77), 2018 (N = 66), 2019 (N = 300), and 2020-2021 (N = 173). Patient characteristics and angiographic and clinical outcomes were compared between these time intervals. This study comprised 671 patients (median age 61.4 years; 71.2% female) with 682 intracranial aneurysms. Over time, we observed an increasing tendency to treat patients presenting with ruptured aneurysms and aneurysms with smaller neck, diameter, and dome widths. Furthermore, we observed a trend towards more off-label use of the WEB for sidewall aneurysms and increased adoption of transradial access for WEB deployment. Moreover, the proportion of patients with adequate WEB occlusion immediately and at last follow-up was significantly higher in more recent year cohorts, as well as lower rates of compaction and retreatment. Mortality and complications did not differ over time. This learning curve study suggests improved experience using the WEB for the treatment of intracranial aneurysms and has yielded higher rates of adequate occlusion over time.

Background Venous thromboembolism (VTE) remains the single most important preventable cause of morbidity and mortality following neurosurgical procedures, with an incidence of approximately 16%. In the absence of stringent guidelines, the variation in current practice patterns could be considerable and was the underlying basis for this study. Objectives Our objective is to evaluate the modality of thromboprophylaxis used by neurosurgeons. Methods In line with “CHERRIES” (Checklist for Reporting Results of Internet E-Surveys) guidelines, an online survey regarding postoperative VTE prophylaxis following elective neurosurgical procedures was created using Google Forms and distributed to 1500 board-certified neurosurgeons in the United States. Results A total of 370 board-certified neurosurgeons (24.7%) responded to the survey. Sequential compression device was the only primary method of thromboprophylaxis used by 27.2% and 26.5% of respondents after elective craniotomy for tumor resection and spine surgery, respectively. Of the chemical prophylaxis, subcutaneous heparin 5000 U every 8 hours was the most commonly used medication followed by enoxaparin 40 mg daily. Most responders were comfortable starting chemical prophylaxis on postoperative day 1, followed by day 2 and day 3 in both types of surgeries. The mean postoperative time of chemical prophylaxis initiation was significantly more delayed by respondents with longer years in practice. Conclusions This study highlights the variation in practice between neurosurgeons in managing postoperative VTE prophylaxis after elective spine and cranial surgeries. In lieu of this variation, our results showed that most neurosurgeons are comfortable starting chemical prophylaxis as soon as postoperative day 1 following both types of procedures.

Background Owing to the rarity of acute ischemic stroke in the pediatric population, evidence supporting the efficacy in children of the various treatments used in adults is scanty. This included mechanical thrombectomy for acute ischemic stroke. Case Description we present the case of an 11-year-old female with acute left hemiparesis, numbness, and left facial droop occurring after tumbling on a trampoline. Computed tomography angiography revealed an 11-mm nonfilling defect in the right middle cerebral artery. She underwent thrombectomy approximately 8.5 hours after the onset of symptoms, and a Thrombolysis in Cerebral Infarction (TICI) scale score of 2b was achieved. She had an uneventful postoperative recovery. Conclusion Pediatric patients likely have more reserve and collateral flow and benefit from a longer therapeutic window following acute ischemic stroke.

Background Numerous randomized controlled trials (RCTs) relevant to the cerebrovascular field have been performed. The fragility index was recently developed to complement the P value and measure the robustness and reproducibility of clinical findings of RCTs. Objective In this study, we evaluate the fragility index for key surgical and endovascular cerebrovascular RCTs and propose a novel RCT classification system based on the fragility index. Methods Cerebrovascular RCTs reported between 2000 and 2018 were reviewed. Six key areas were specifically targeted in relation to stroke, carotid stenosis, cerebral aneurysms, and subarachnoid hemorrhage. The correlation between fragility index, number of patients lost to follow-up, and fragility quotient were evaluated to propose a classification system for the robustness of the studies. Results A total of 20 RCTs that reported significant differences between both study groups in terms of the primary outcome were included. The median fragility index for the trials was 5.5. An additional 30 randomly selected RCTs were added to propose a classification system with high reliability. The difference between the number of patients lost to follow-up and fragility index inversely correlated with the fragility quotient and was used to divide the robustness of the RCTs into 3 classes reflecting the reproducibility of the trial. Conclusions Neurosurgeons and neurointerventionalists should exercise caution with interpreting the results of cerebrovascular RCTs, especially when the sample size and events numbers are small and there is a high number of patients who were lost to follow-up, as quantitatively identified using the proposed classification system.

The concept of spinal cord injury has existed since the earliest human civilizations, with the earliest documented cases dating back to 3000 BC under the Egyptian Empire. Howevr, an understanding of this field developed slowly, with real advancements not emerging until the 20th century. Technological advancements including the dawn of modern warfare producing mass human casualties instigated revolutionary advancement in the field of spine injury and its management. Spine surgeons today encounter "Chance" and "Holdsworth" fractures commonly; however, neurosurgical literature has not explored the history of these physicians and their groundbreaking contributions to the modern understanding of spine injury. A literature search using a historical database, Cochrane, Google Scholar, and PubMed was performed. As needed, hospitals and native universities were contacted to add their original contributions to the literature. George Quentin Chance, a Manchester-based British physician, is well known to many as an eminent radiologist of his time who described the eponymous fracture in 1948. Sir Frank Wild Holdsworth (1904-1969), a renowned British orthopedic surgeon who laid a solid foundation for rehabilitation of spinal injuries under the aegis of the Miners' Welfare Commission, described in detail the management of thoraco-lumbar junctional rotational fracture. The work of these 2 men laid the foundation for today's understanding of spinal instability, which is central to modern spine injury classification and management algorithms. This historical vignette will explore the academic legacies of Sir Frank Wild Holdsworth and George Quentin Chance, and the evolution of spinal instability and spine injury classification systems that ensued from their work.

Aneurysm clips are indispensable tools in the armamentarium of vascular neurosurgeons. The history of the development of aneurysm clips is witness to ingenuity and tenacity in treating a potentially devastating disease. Few know the stories of their innovators and the inspiration behind their designs. Hence, we present this historical vignette in an attempt to shed more light on the pioneers who shaped the evolution of aneurysm clips as we know them. A comprehensive literature search was performed using PubMed, Google Scholar, Google Books, and library historical archives, as well as personal communications with relatives, colleagues, and institutions of the surgeon-designers. We present the following aneurysm clip innovators and chronicle their biographies and contributions: Herbert Olivecrona (1891-1980), Frank Mayfield (1908-1991), Charles Drake (1920-1998), Joseph McFadden (1920-present), Thoralf Sundt Jr. (1930-1992), William M. Lougheed (1923-2004), William B. Scoville (1906-1984), Milton D. Heifetz (1921-2015), Gazi Yaşargil (1925-present), Kenichiro Sugita (1932-1994), and Robert Spetzler (1944-present). Although this compilation of eponymous clips is by no means complete, we hope that it provides an informative historical perspective and an inspiration for aspiring neurosurgeons. The history of aneurysm surgery, an entity once deemed inoperable, teaches us the importance of innovation in medicine.

BackgroundThe literature suggests that minority racial and ethnic groups have lower treatment rates for unruptured intracranial aneurysms (UIA). It is uncertain how these disparities have changed over time.MethodsA cross-sectional study using the National Inpatient Sample database covering 97% of the USA population was carried out.ResultsA total of 213 350 treated patients with UIA were included in the final analysis and compared with 173 375 treated patients with aneurysmal subarachnoid hemorrhage (aSAH) over the years 2000–2019. The mean (SD) age of the UIA and aSAH groups was 56.8 (12.6) years and 54.3 (14.1) years, respectively. In the UIA group, 60.7% were white patients, 10.2% were black patients, 8.6% were Hispanic, 2% were Asian or Pacific Islander, 0.5% were Native Americans, and 2.8% were others. The aSAH group comprised 48.5% white patients, 13.6% black patients, 11.2% Hispanics, 3.6% Asian or Pacific Islanders, 0.4% Native Americans, and 3.7% others. After adjusting for covariates, black patients (OR 0.637, 95% CI 0.625 to 0.648) and Hispanic patients (OR 0.654, 95% CI 0.641 to 0.667) had lower odds of treatment compared with white patients. Medicare patients had higher odds of treatment than private patients, while Medicaid and uninsured patients had lower odds. Interaction analysis showed that non-white/Hispanic patients with any insurance/no insurance had lower treatment odds than white patients. Multivariable regression analysis showed that the treatment odds of black patients has improved slightly over time, while the odds for Hispanic patients and other minorities have remained the same over time.ConclusionThis study from 2000 to 2019 shows that disparities in the treatment of UIA have persisted but have slightly improved over time for black patients while remaining constant for Hispanic patients and other minority groups.

Background: Aneurysmal persistence after flow diversion (FD) occurs in 5% to 25% of aneurysms, which may necessitate retreatment. There are limited data on safety/efficacy of repeat FD—a frequently utilized strategy in such cases. Methods: A series of consecutive patients undergoing FD retreatment from 15 centers were reviewed (2011–2019), with inclusion criteria of repeat FD for the same aneurysm at least 6 months after initial treatment, with minimum of 6 months post-retreatment imaging. The primary outcome was aneurysmal occlusion, and secondary outcome was safety. A multivariable logistic regression model was constructed to identify predictors of incomplete occlusion (90%–99% and Results: Ninety-five patients (median age, 57 years; 81% women) harboring 95 aneurysms underwent 198 treatment procedures. Majority of aneurysms were unruptured (87.4%), saccular (74.7%), and located in the internal carotid artery (79%; median size, 9 mm). Median elapsed time between the first and second treatment was 12.2 months. Last available follow-up was at median 12.8 months after retreatment, and median 30.6 months after the initial treatment, showing complete occlusion in 46.2% and near-complete occlusion (90%–99%) in 20.4% of aneurysms. There was no difference in ischemic complications following initial treatment and retreatment (4.2% versus 4.2%; P >0.99). On multivariable regression, fusiform morphology had higher nonocclusion odds after retreatment (odds ratio [OR], 7.2 [95% CI, 1.97–20.8]). Family history of aneurysms was associated with lower odds of nonocclusion (OR, 0.18 [95% CI, 0.04–0.78]). Likewise, positive smoking history was associated with lower odds of nonocclusion (OR, 0.29 [95% CI, 0.1–0.86]). History of hypertension trended toward incomplete occlusion (OR, 3.10 [95% CI, 0.98–6.3]), similar to incorporated branch into aneurysms (OR, 2.78 [95% CI, 0.98–6.8]). Conclusions: Repeat FD for persistent aneurysms carries a reasonable success/safety profile. Satisfactory occlusion (100% and 90%–99% occlusion) was encountered in two-thirds of patients, with similar complications between the initial and subsequent retreatments. Fusiform morphology was the strongest predictor of retreatment failure.

OBJECTIVE Transradial access (TRA) is commonly utilized in neurointerventional procedures. This study compared the technical and clinical outcomes of the use of TRA versus those of transfemoral access (TFA) for intracranial aneurysm embolization with the Woven EndoBridge (WEB) device. METHODS This is a secondary analysis of the Worldwide WEB Consortium, which comprises multicenter data related to adult patients with intracranial aneurysms who were managed with the WEB device. These aneurysms were categorized into two groups: those who were treated with TRA or TFA. Patient and aneurysm characteristics and technical and clinical outcomes were compared between groups. Propensity score matching (PSM) was used to match groups according to the following baseline characteristics: age, sex, subarachnoid hemorrhage, aneurysm location, bifurcation aneurysm, aneurysm with incorporated branch, neck width, aspect ratio, dome width, and elapsed time since the last follow-up imaging evaluation. RESULTS This study included 682 intracranial aneurysms (median [interquartile range] age 61.3 [53.0–68.0] years), of which 561 were treated with TFA and 121 with TRA. PSM resulted in 65 matched pairs. After PSM, both groups had similar characteristics, angiographic and functional outcomes, and rates of retreatment, thromboembolic and hemorrhagic complications, and death. TFA was associated with longer procedure length (median 96.5 minutes vs 72.0 minutes, p = 0.006) and fluoroscopy time (28.2 minutes vs 24.8 minutes, p = 0.037) as compared with TRA. On the other hand, deployment issues were more common in those treated with TRA, but none resulted in permanent complications. CONCLUSIONS TRA has comparable outcomes, with shorter procedure and fluoroscopy time, to TFA for aneurysm embolization with the WEB device.

Posterior circulation aneurysms are often associated with a higher risk of rupture and compressive symptoms compared to their anterior circulation counterpart. Due to high morbidity and mortality associated with microsurgical treatment of those aneurysms, endovascular therapy gained ascendance as the preferred method of treatment. Flow diversion has emerged as a promising treatment option for posterior circulation aneurysms with a higher occlusion rate compared to other endovascular techniques and a lower complication rate compared to microsurgery. While treatment of saccular and dissecting aneurysms is often associated with comparatively good outcomes, fusiform and dolichoectatic aneurysms should be carefully selected prior to treatment to avoid devastating thromboembolic complications. Occlusion of covered posterior circulation branches showed no correlation with ischemic complications, and appropriate antiplatelet regimen and switching Clopidogrel nonresponders to different antiplatelet agents were associated with lower complication rates following flow diversion of posterior circulation aneurysms.

OBJECTIVECurrently, there is no established standard regarding the ideal number of external ventricular drain (EVD) clamp trials performed before ventriculoperitoneal (VP) shunt insertion following nontraumatic subarachnoid hemorrhage (SAH). In this study, the authors aimed to evaluate this relationship.METHODSA retrospective review of all patients presenting with SAH between July 2007 and December 2016 was performed. Patients with SAH who had received an EVD within the first 24 hours of hospital admission and had undergone at least 1 clamp trial prior to EVD removal were eligible for inclusion in the study. Patient demographics, clinical presentations, SAH etiologies and grades, clamp trial data, hospital lengths of stay, and functional outcomes were recorded.RESULTSOne hundred fourteen patients with nontraumatic SAH complicated by posthemorrhagic hydrocephalus were included in the study. The median patient age was 57 years (range 28–90 years), with a male/female ratio of 1:1.7. A ruptured aneurysm was the underlying etiology of SAH in 79.8% of patients. A majority of patients (69.4%) had a Hunt and Hess grade III–V on admission. The median number of clamp trials performed was 2 (range 1–6). A VP shunt was required in 40.4% of patients. In those who underwent 2 and 3 clamp trials, 60% and 38.9%, respectively, did not require subsequent VP shunt placement.CONCLUSIONSSurgical placement of a VP shunt is associated with complications. Clamp trials are routinely performed before making the decision to insert a shunt. In the present study, the authors found that a significant percentage of patients passed their second and third clamp trials without requiring subsequent shunt insertion. These data support performing multiple clamp trials prior to shunt placement.

OBJECTIVEFlow diversion for posterior circulation aneurysms performed using the Pipeline embolization device (PED) constitutes an increasingly common off-label use for otherwise untreatable aneurysms. The safety and efficacy of this treatment modality has not been assessed in a multicenter study.METHODSA retrospective review of prospectively maintained databases at 8 academic institutions was performed for the years 2009 to 2016 to identify patients with posterior circulation aneurysms treated with PED placement.RESULTSA total of 129 consecutive patients underwent 129 procedures to treat 131 aneurysms; 29 dissecting, 53 fusiform, and 49 saccular lesions were included. At a median follow-up of 11 months, complete and near-complete occlusion was recorded in 78.1%. Dissecting aneurysms had the highest occlusion rate and fusiform the lowest. Major complications were most frequent in fusiform aneurysms, whereas minor complications occurred most commonly in saccular aneurysms. In patients with saccular aneurysms, clopidogrel responders had a lower complication rate than did clopidogrel nonresponders. The majority of dissecting aneurysms were treated in the immediate or acute phase following subarachnoid hemorrhage, a circumstance that contributed to the highest mortality rate in those aneurysms.CONCLUSIONSIn the largest series to date, fusiform aneurysms were found to have the lowest occlusion rate and the highest frequency of major complications. Dissecting aneurysms, frequently treated in the setting of subarachnoid hemorrhage, occluded most often and had a low complication rate. Saccular aneurysms were associated with predominantly minor complications, particularly in clopidogrel nonresponders.

BackgroundThe Woven EndoBridge (WEB) device is a novel intrasaccular flow disruptor tailored for bifurcation aneurysms. We aim to describe the degree of aneurysm occlusion at the latest follow-up, and the rate of complications of aneurysms treated with the WEB device stratified according to rupture status.MethodsOur data were taken from the WorldWideWeb Consortium, an international multicenter cohort including patients treated with the WEB device. Aneurysms were classified into two groups: ruptured and unruptured. We compared clinical and radiologic outcomes of both groups. Propensity score matching (PSM) was done to match according to age, gender, bifurcation, location, prior treatment, neck, height, dome width, daughter sac, incorporated branch, pretreatment antiplatelets, and last imaging follow-up.ResultsThe study included 676 patients with 691 intracranial aneurysms (529 unruptured and 162 ruptured) treated with the WEB device. The PSM analysis had 55 pairs. In both the unmatched (85.8% vs 84.3%, p=0.692) and matched (94.4% vs 83.3%, p=0.066) cohorts there was no significant difference in the adequate occlusion rate at the last follow-up. Likewise, there were no significant differences in both ischemic and hemorrhagic complications between the two groups. There was no documented aneurysm rebleeding after WEB device implantation.ConclusionThere was no significant difference in both the radiologic outcomes and complications between unruptured and ruptured aneurysms. Our findings support the feasibility of treatment of ruptured aneurysms with the WEB device.

Current evidence regarding the benefit of preoperative embolization (POE) of meningiomas is inconclusive. This systematic review and meta-analysis aims to evaluate the safety profile of the procedure and to compare outcomes in embolized versus non-embolized meningiomas. PubMed was queried for studies after January 1990 reporting outcomes of POE. Pertinent variables were extracted and synthesized from eligible articles. Heterogeneity was assessed using I2, and random-effects model was employed to calculate pooled 95% CI effect sizes. Publication bias was assessed using funnel plots and Harbord's and Begg's tests. Meta-analyses were used to assess estimated blood loss and operative duration (mean difference; MD), gross-total resection (odds ratio; OR), and postsurgical complications and postsurgical mortality (risk difference; RD). Thirty-four studies encompassing 1782 preoperatively embolized meningiomas were captured. The pooled immediate complication rate following embolization was 4.3% (34 studies, n = 1782). Although heterogeneity was moderate to high (I2 = 35-86%), meta-analyses showed no statistically significant differences in estimated blood loss (8 studies, n = 1050, MD = 13.9 cc, 95% CI = -101.3 to 129.1), operative duration (11 studies, n = 1887, MD = 2.4 min, 95% CI = -35.5 to 30.8), gross-total resection (6 studies, n = 1608, OR = 1.07, 95% CI = 0.8-1.5), postsurgical complications (12 studies, n = 2060, RD = 0.01, 95% CI = -0.04 to 0.07), and postsurgical mortality (12 studies, n = 2060, RD = 0.01, 95% CI = 0-0.01). Although POE is relatively safe, no clear benefit was observed in operative and postoperative outcomes. However, results must be interpreted with caution due to heterogeneity and selection bias between studies. Well-controlled future investigations are needed to define the patient population most likely to benefit from the procedure.

Due to electronic residency applications, US Medical Licensing Examination Step 1 scores are frequently used by orthopedic surgery program directors to screen applicants. Prospective applicants therefore often use Step 1 scores as a proxy for specialty competitiveness. The goal of this investigation was two-fold: (1) to determine whether trends in Step 1 scores are indicative of trends in competitiveness of orthopedic surgery and (2) to report the characteristics that optimize a US medical student's match success. A retrospective review of published National Resident Matching Program data from 2009 to 2018 was performed for orthopedic surgery residency applicants. Additional data from the Charting Outcomes reports were used for specific analyses of applicant characteristics. From 2009 to 2018, the number of orthopedic surgery residency positions grew at an annual rate of 1.51% (95% confidence interval [CI], 1.37% to 1.64%; P P =.006) annual increase in the number of applicants who ranked orthopedic surgery as their preferred specialty choice (only choice or first choice). There were no significant changes in the applicant-to-position ratio (95% CI, −0.85% to 0.37%; P =.483) or the match rate for US seniors who ranked orthopedic surgery as their preferred choice (95% CI, −0.23% to 0.87%; P =.313). Increases in mean Step 1 scores of matched orthopedic surgery applicants parallel national Step 1 growth trends (0.49% vs 0.44%, respectively). Although orthopedic surgery is currently a competitive specialty to match into, this has been the case since 2009. Increasing Step 1 scores of matched applicants is not unique to orthopedic surgery and should not be misinterpreted as a proxy for increasing competitiveness of the specialty. [ Orthopedics . 2020;43(6):e616–e622.]

Background Aneurysmal persistence after flow-diversion (FD) occurs in 5–25% of aneurysms which might necessitate further treatment. A frequently used retreatment paradigm utilizes the deployment of another flow-diverting device (FDD) in a telescoping fashion within the existing device. There are no current data evaluating this strategy. Methods A retrospective review of patients undergoing FD retreatment from 15 centers was performed, with inclusion criteria being repeat FD occurring for the same aneurysm at least 6 months after initial treatment, with minimum of 6 months of imaging follow-up after retreatment. Primary outcome was aneurysmal occlusion, and secondary outcomes were safety and complications. A multivariable logistic regression model was constructed to identify predictors of persistence/occlusion after retreatment. Comparative Kaplan-Meier curves were developed to assess the effect of early (6–12 months since initial treatment) vs late retreatment (>12 months since initial treatment) on the cumulative incidence of aneurysm occlusion over time. Results Ninety-five patients (median age 57, 81% females) harboring 95 aneurysms underwent 198 treatment procedures. In our cohort, 87.4% of aneurysms were unruptured; 74.7% were saccular and 79% were located in the internal carotid artery (median maximal diameter 9-mm), with 87 patients treated twice and 8 patients treated thrice. Median elapsed-time between first and second treatment was 12.2 months. Last available follow-up was performed at median of 12.8 months after retreatment, and median of 30.6 months after initial treatment, showing complete occlusion in 46.2%, and near-complete occlusion (90–99%) in 20.4% of aneurysms. No difference in ischemic complications following initial treatment and retreatment (4.2% vs 4.2; p>0.99). On multivariable logistic regression, fusiform morphology was associated with higher odds of non-occlusion after retreatment (OR 7.2; p=0.003), with history of hypertension and incorporated branch into aneurysms trending toward incomplete occlusion (p=0.055 and p=0.054; respectively). Family history of aneurysms and positive smoking history were associated with higher odds of complete occlusion (p=0.019 and p=0.026; respectively). Kaplan-Meier curves comparative estimators showed no significant difference in time-to-occlusion between the two groups (log rank test, p=0.48). Conclusion Repeat flow diversion for persistent aneurysms is safe and effective. Fusiform morphology is the strongest predictor of aneurysmal persistence after repeat flow diversion. Disclosures M. Salem: None. A. Sweid: None. A. Kuhn: None. A. Dmytriw: None. S. Gomez-Paz: None. G. Maragkos: None. M. Waqas: None. C. Parra-Farinas: None. A. Salehani: None. N. Adeeb: None. P. Brouwer: None. G. Pickett: None. M. Ghuman: None. V. Yang: None. A. Weill: None. C. Cognard: None. L. Renieri: None. P. Kan: None. N. Limbucci: None. V. Mendes Pereira: None. M. Harrigan: None. A. Puri: None. E. Levy: None. J. Moore: None. C. Ogilvy: None. T. Marotta: None. P. Jabbour: None. A. Thomas: None.

Background and PurposeThe Penumbra JET 7 reperfusion catheter is used in the revascularization of large vessel occlusions in acute ischemic stroke. Description of its use in clinical practice remains limited. Our purpose is to describe our initial experience with the Penumbra JET 7 reperfusion catheter and to report on its safety and efficacy in different thrombectomy techniques.Materials and MethodsWe conducted a retrospective study of 50 patients treated with thrombectomy using the Penumbra JET 7 reperfusion catheter. Mean patient age and admission National Institutes of Health Stroke Scale were 70.6 and 17.76, respectively. The most common sites of vessel occlusion were the M1 segment (72%) followed by distal internal carotid artery (14%). Thrombectomy was performed using the direct aspiration first-pass technique and/or aspiration in conjunction with a stent retriever.ResultsRevascularization was achieved in a total of 44 cases (88%). Successful navigation of the Penumbra JET 7 reperfusion catheter to the occlusion site with clot engagement was achieved in 94% of cases. Mean time from vascular access to revascularization was 31.60 min. No catheter-related complications occurred. Clinical outcome data were collected from 43 patients (86%). Of those patients, 51% achieved good outcome (modified Rankin score of 0–2) at 60 or more days follow-up, 28% had poor outcome (modified Rankin score of 3–5), and 9 patients died (21%).ConclusionThe use of the Penumbra JET 7 reperfusion catheter for treatment of acute ischemic stroke was observed to be safe and effective with appropriate revascularization outcomes in different thrombectomy techniques.

Tumefactive multiple sclerosis (TMS) is a rare variant of multiple sclerosis (MS) with atypical features that pose a diagnostic challenge. In this study, we report a case of cervical MS in a 19-year-old patient that was diagnosed based on the MRI findings and cerebrospinal fluid analysis. The patient was treated with high-dose steroid and five sessions of plasma exchange with significant improvement.

Background Flow diversion for basilar apex aneurysms has rarely been reported. Objective To assess flow diversion for basilar apex aneurysms in a multicenter cohort. Methods Retrospective review of prospectively maintained databases at 8 academic institutions was performed from 2009 to 2016 to identify patients with basilar apex aneurysms treated with flow diversion. Clinical and radiographic data were analyzed. Results Sixteen consecutive patients (median age 54.5 yr) underwent 18 procedures to treat 16 basilar apex aneurysms with either the Pipeline Embolization Device (Medtronic Inc, Dublin, Ireland) or Flow Redirection Endoluminal Device (Microvention, Tustin, California). Five aneurysms (31.3%) were treated in the setting of subarachnoid hemorrhage. Seven aneurysms (43.8%) were treated with flow diversion alone, while 9 (56.2%) underwent flow diversion and adjunctive coiling. At a median follow-up of 6 mo, complete (100%) and near-complete (90%-99%) occlusion was noted in 11 (68.8%) aneurysms. Incomplete occlusion occurred more commonly in patients treated with flow diversion alone compared to those with adjunctive coiling. Patients with partial occlusion were significantly younger. Retreatment with an additional flow diverter and adjunctive coiling occurred in 2 aneurysms with wide necks. There was 1 mortality in a patient (6.3%) who experienced posterior cerebral artery and cerebellar strokes as well as subarachnoid hemorrhage after the placement of a flow diverter. Minor complications occurred in 2 patients (12.5%). Conclusion Flow diversion for the treatment of basilar apex aneurysms results in acceptable occlusion rates in highly selected cases. Both primary flow diversion and rescue after failed clipping or coiling resulted in a modified Rankin Scale score that was either equal or better than at presentation and the technology represents a viable alternative or adjunctive option.

OBJECTIVEChronic subdural hematoma (CSDH) is commonly encountered in neurosurgical practice. However, surgical evacuation remains complicated by a high rate of reoperation. The optimal surgical approach to reduce the reoperation rate has not been determined. In the current study, the authors evaluated the prognostic value of clinical and radiographic factors to predict reoperation in the context of CSDH.METHODSA retrospective review of 325 CSDH patients admitted to an academic medical center in the United States, between 2006 and 2016, was performed. Clinical and radiographic factors predictive of the need for CSDH reoperation were identified on univariable and multivariable analyses.RESULTSUnivariable analysis showed that warfarin use, clopidogrel use, mixed hypo- and isointensity on T1-weighted MRI, greater preoperative midline shift, larger hematoma/fluid residual on first postoperative day CT, lesser decrease in hematoma size after surgery, use of monitored anesthesia care (MAC), and lack of intraoperative irrigation correlated with a significantly higher rate of reoperation. Multivariable analysis, however, showed that only the presence of loculation, clopidogrel or warfarin use, and percent of hematoma change after surgery significantly predicted the need for reoperation. Our results showed that 0% (no reduction), 50%, and 100% hematoma maximum thickness change (complete resolution of hematoma after surgery) were associated with a 41%, 6%, and < 1% rate of reoperation, respectively. The use of drains, either large diameter or small caliber, did not have any effect on the likelihood of reoperation.CONCLUSIONSAmong many factors, clopidogrel or warfarin use, hematoma loculation on preoperative CT, and the amount of hematoma evacuation on the first postoperative CT were the strongest predictors of reoperation.

Introduction Ophthalmic segment aneurysms may present with visual symptoms due to direct compression of the optic nerve. Treatment of these aneurysms with the Pipeline embolization device (PED) often results in visual improvement. Flow diversion, however, has also been associated with occlusion of the ophthalmic artery and visual deficits in a small subset of cases. Case report A 49-year-old Caucasian female presented with subarachnoid hemorrhage due to a ruptured anterior communicating artery aneurysm. On follow-up imaging, the patient was found to have a right asymptomatic ophthalmic segment aneurysm. Due to the irregular shape of the aneurysm and history of aneurysmal subarachnoid hemorrhage, the decision was made to treat the aneurysm with a PED. Postoperatively, the patient complained of floaters in the right eye. Detailed ophthalmologic examination showed retinal hemorrhage and cotton-wool spots on the macula. Such complication after PED placement has never been reported in the literature. Conclusion Visual complications after PED placement for treatment of ophthalmic segment aneurysms are rare. It is thought that even in cases where the ophthalmic artery occludes, patients remain asymptomatic due to the rich collateral supply from the external carotid artery branches. Here we report a patient who developed an acute retinal hemorrhage after PED placement.

Background The choice of appropriate antiplatelet therapy before the Pipeline Embolization Device (PED) placement is usually guided by platelet function testing such as light transmission aggregometry (LTA). In this study, we aimed to define the optimal threshold LTA value for clopidogrel responsiveness to predict the risk of postprocedural thromboembolic complications and to help guide appropriate antiplatelet regimen. Methods A prospectively maintained database at an academic neurosurgical center in the United States was retrospectively analyzed from 2014 to 2017 to identify patients with unruptured intracranial aneurysms treated with the PED. Clinical and radiographic data were analyzed to identify thromboembolic complications in the context of platelet function testing performed by LTA. Results A total of 95 procedures were performed for PED placement to treat 110 unruptured intracranial aneurysms. Thromboembolic complications were encountered in 4 (4.2%) of these patients. After stratifying the complication rate based on the maximal extent of platelet aggregation after administration of an exogenous platelet agonist, a marked increase in thromboembolic events was observed in patients with LTA values greater than 50%. When LTA was dichotomized based on this value, patients with an LTA value less than 50% had a thromboembolic complication rate of 1.3% (1/80), compared with 20% (3/15) for those with LTA values ≥50% (P = 0.001). Conclusions We observed the greatest increase in the rate of thromboembolic complications with LTA values of ≥50%. This can serve as an appropriate cut-off value for determining the clopidogrel response in patients undergoing endovascular treatment with the PED.

Introduction The objective of this study was to analyze patients' perceptions of their headaches both before and after Pipeline flow diversion treatment of their unruptured intracranial aneurysms, with the goal of identifying prognostic factors associated with headache patterns to improve predictions of overall outcomes. Methods We retrospectively identified 133 patients treated with the Pipeline embolization device (PED) between January 1, 2014, and December 31, 2016, at an academic institution in the United States. Patients with at least 6 months of clinical follow-up, who had completed a validated telephone survey assessing their headache perceptions before and after treatment of their UIAs, were included. Results Sixty patients (57.7%) responded to the questionnaire. Median aneurysm size was 6.3 mm. Thirty-two patients (53.3%) presented with headaches before treatment, which had a median intensity of 7 out of 10 (range, 3–10). On postprocedural evaluation, 8 patients (25%) had complete resolution of their headaches. Of the 24 (75%) patients with persistent headaches, the frequency and severity of the headaches decreased or remained the same in most (58.3%) patients. Eleven (18.3%) patients had new-onset headaches. This study found an association between aneurysm size and a reduction in headache frequency and severity after PED treatment. No significant association was found between headache persistence, severity, or frequency and patient demographics, aneurysm characteristics, and other comorbidities. Conclusion An overall improvement of headaches in patients with UIAs who underwent treatment with the PED was observed, particularly in patients harboring large aneurysms and who had presented with daily headaches.

Introduction Dr. Collin S. MacCarty (1915–2003) invented the MacCarty keyhole, which is now widely used as the starting burr hole for orbitozygomatic craniotomy. We present a historical vignette on MacCarty's life and chronicle his contributions to neurosurgery. Methods A detailed search for articles relating to the biography and professional career of Dr. MacCarty was conducted on PubMed and Google Scholar by using the key words “Collin MacCarty” and “MacCarty keyhole.” References found in those articles were also reviewed. Results On September 20, 1915, Collin MacCarty was born in Rochester, Minnesota. MacCarty was exposed to the medical field at an early age. He witnessed legendary surgeons like Alfred Adson perform brain and spine operations. Expectedly, MacCarty pursued a career in neurosurgery. He was influenced by Walter Dandy as a house office at Johns Hopkins and completed his neurosurgical training at the Mayo Clinic under Adson. In a distinguished career in neurosurgery at the Mayo Clinic, MacCarty served many important roles, including Chairman of the Department of Neurosurgery from 1963 to 1975 and President of the American Association of Neurological Surgeons. He was world-renowned for his vast experience with meningiomas. In 1961, MacCarty described a burr hole to expose the periorbita and frontal dura while approaching intraorbital meningiomas. This burr hole became immortalized as the “MacCarty keyhole” and is used widely today in frontotemporal orbitozygomatic approaches. Conclusions Collin S. MacCarty was an influential neurosurgeon. Among a multitude of contributions, he is most well-known for inventing the “MacCarty keyhole” which is widely implemented nowadays as the starting point for orbitozygomatic approaches.

Objectives: Spinal arteriovenous fistula (AVF) is the most common spinal vascular lesion and constitutes an abnormal communication between a feeder artery and a draining vein. Arterialization of the venous plexus leads to venous hypertension; consequent edema and congestion of the spinal cord are associated with progressive neurological decline. Patients and Methods: In this report, we describe two unique cases of type I cervical spinal AVF, in which a radiculomeningeal artery forms an intradural fistula that drains into the ventral venous plexus. Results: Both patients underwent surgical obliteration of the fistula with complete occlusion confirmed on postoperative angiography. Conclusion: Both cases do not fit into the current classification scheme. A modified classification is proposed.

Background Stent-assisted coil embolization and flow diversion with the Pipeline embolization device (PED) are both effective endovascular treatment options for ophthalmic segment aneurysms (OSAs) of the internal carotid artery. Here we present a large comparative cohort study. Methods A multicenter, retrospective cohort comparison study of consecutively treated OSAs was conducted at 2 academic institutions in the United States comparing stent-coiling (between 2007 and 2015) and PED (between 2011 and 2016). Results A total of 62 of OSAs were treated with stent-coiling and 106 were treated with the PED. The stent-coiling–treated aneurysms were larger, although the maximum diameter was not significantly different between the 2 groups (P = 0.05). The median duration of follow-up was 22.5 months for the stent-coiling group and 8.7 months for the PED group (P = 0.0002). Complete occlusion at last follow-up was achieved in 75.9% of aneurysms in the stent-coiling group and in 81.1% of aneurysms in the PED group (P = 0.516). The retreatment rate was higher with stent-coiling, but the difference did not reach statistical significance (P = 0.062). A good functional outcome was achieved in 96.6% of patients in the stent-coiling group and in 94.7% of those in the PED group (P = 0.707). The rate of neurologic complications was 4.8% in the stent-coiling group and 9.4% in the PED group (P = 0.376). Conclusion Stent-coiling and the PED were equally effective for treating OSAs. There were no significant differences in terms of procedural complications, angiographic, functional, and visual outcomes. PED may be more favorable for multiple adjacent OSAs.

Background The development of stent-assisted coiling has allowed for the endovascular treatment of wide-necked bifurcation aneurysms. A variety of options exist, and little is known about the optimal stent configuration in this setting. We report a large multicenter experience of stent-assisted coiling of bifurcations aneurysms using a single stent, with attention to factors predisposing to aneurysm recanalization. Objective To assess the safety and efficacy of single stent-assisted coiling, in addition to analyzing the factors associated with recanalization, and proposal of a predictive scoring scale. Methods A multicenter retrospective analysis of bifurcation aneurysms treated with a single stent-assisted coiling technique between 2007 and 2015 was performed. Clinical and radiographic data were collected and used to develop a scoring system to predict aneurysm occlusion. Results A total of 74 bifurcation aneurysms were treated with single stent-assisted coiling. At a median follow-up of 15.2 mo, complete occlusion or remnant neck was achieved in 90.6% of aneurysms. Aneurysm location, maximal diameter, neck size, and alpha angle were predictive of aneurysm occlusion at last follow-up. A scoring system to predict complete occlusion based on these factors was developed. An increasing score correlated with a higher rate of complete occlusion. Conclusion The treatment of bifurcation aneurysm using single stent technique for stent-assisted coiling is safe and effective. Complete occlusion or remnant neck occlusion was achieved in 90.6% of cases. Class III aneurysms can be effectively treated using a single stent, while class I may require Y-stent technique.

Introduction Flow diversion has become a popular treatment option for a variety of cerebral aneurysms. We sought to compare conscious sedation and general anesthesia for flow diverter placement in a matched cohort study. Methods Patients who underwent flow diverter placement under conscious sedation were matched on the basis of age, sex, American Society of Anesthesiologists classification, aneurysm location, and aneurysm size to patients who received general anesthesia. Results Seventy patients undergoing flow diverter placement under conscious sedation were matched to 70 patients using general anesthesia. There were no statistically significant differences in gender, age, pretreatment modified Rankin Scale scores, or American Society of Anesthesiologists class. Aneurysms were located primarily in the internal carotid artery (87.1%) and posterior circulation (11.4%). Maximal aneurysm diameter and history of aneurysm rupture did not differ between the 2 groups. Duration of flow diverter placement was significantly longer in the general anesthesia group. The number of flow diverters placed was also higher in the general anesthesia group. Complete occlusion was achieved in 75% of aneurysms treated under conscious sedation and 82.4% under general anesthesia. Good functional outcome at last follow-up was recorded in 97.1% of cases of conscious sedation and 96.8% of cases of general anesthesia. The rate of thromboembolic and hemorrhagic neurologic complications was comparable between both groups. Conclusions Placement of a flow diverter can be safely performed under conscious sedation and is associated with reduced procedure length. The ideal candidate is cooperative, requires an intervention that is not too complex, and has an experienced operator performing the intervention.