Neurointerventional procedural volume per hospital in United States: implications for comprehensive stroke center designation

Mechanical thrombectomy in patients with acute ischemic stroke in the USA before and after time window expansion

BACKGROUND

In 2018, the time window for mechanical thrombectomy eligibility in patients with acute ischemic stroke increased from within 6 hours to within 24 hours of symptom onset. The purpose of this study was to evaluate the effect of window expansion on procedural and hospital volumes and patient outcomes at a national level.

METHODS

We conducted a retrospective cohort study of patients with acute ischemic stroke undergoing mechanical thrombectomy using data from the National Inpatient Sample. We compared the numbers of mechanical thrombectomy procedures and performing hospitals between 2017 and 2019 in the USA, and the proportion of patients discharged home/self-care, those with in-hospital mortality and post-procedural intracranial hemorrhage (2019 vs 2017) after adjustment for potential confounders.

RESULTS

The number of patients with ischemic stroke who underwent mechanical thrombectomy increased from 16 960 in 2017 to 28 120 in 2019. There was an increase in the number of hospitals performing mechanical thrombectomy (501 in 2017, 585 in 2019) and those performing ≥50 procedures/year (97 in 2017, 199 in 2019; P<0.001). The odds of in-hospital mortality decreased (OR 0.79, 95% CI 0.66 to 0.94, P=0.008) and the odds of intracranial hemorrhage increased (OR 1.18, 95% CI 1.06 to 1.31, P=0.003) in 2019 compared with 2017, with no change in odds of discharge to home.

CONCLUSIONS

The window expansion for mechanical thrombectomy for patients with acute ischemic stroke was associated with an increase in the numbers of mechanical thrombectomy procedures and performing hospitals with a reduction of in-hospital mortality in the USA.

Effect of Radiographic Contrast Media Shortage on Stroke Evaluation in the United States

BACKGROUND AND PURPOSE

We performed this study to identify the effect of the nationwide iodinated contrast media shortage due to reduction in GE Healthcare production, initiated on April 19, 2022, on the evaluation of patients with stroke.

MATERIALS AND METHODS

We analyzed the data on 72,514 patients who underwent imaging processed with commercial software in a sample of 399 hospitals in United States from February 28, 2022, through July 10, 2022. We quantified the percentage change in the daily number of CTAs and CTPs performed before and after April 19, 2022.

RESULTS

The daily counts of individual patients who underwent CTAs decreased (a 9.6% reduction, P = .002) from 1.584 studies per day per hospital to 1.433 studies per day per hospital. The daily counts of individual patients who underwent CTPs decreased (a 25.9% reduction, P = .003) from 0.484 studies per day per hospital to 0.358 studies per day per hospital. A significant reduction in CTPs using GE Healthcare contrast media (43.06%, P < .001) was seen but not in CTPs using non-GE Healthcare contrast media (increase by 2.93%, P = .29). The daily counts of individual patients with large-vessel occlusion decreased (a 7.69% reduction) from 0.124 per day per hospital to 0.114 per day per hospital.

CONCLUSIONS

Our analysis reported changes in the use of CTA and CTP in patients with acute ischemic stroke during the contrast media shortage. Further research needs to identify effective strategies to reduce the reliance on contrast media-based studies such as CTA and CTP without compromising patient outcomes.

Regional Variability in the Care and Outcomes of Subarachnoid Hemorrhage Patients in the United States

Background and Objectives

Regional variability in subarachnoid hemorrhage (SAH) care is reported in physician surveys. We aimed to describe variability in SAH care using patient-level data and identify factors impacting hospital outcomes and regional variability in outcomes.

Methods

A retrospective multi-center cross-sectional cohort study of consecutive non-traumatic SAH patients in the Vizient Clinical Data Base, between January 1st, 2009 and December 30th, 2018 was performed. Participating hospitals were divided into US regions: Northeast, Midwest, South, West. Regional demographics, co-morbidities, severity-of-illness, complications, interventions and discharge outcomes were compared. Multivariable logistic regression was performed to identify factors independently associated with primary outcomes: hospital mortality and poor discharge outcome. Poor discharge outcome was defined by the Nationwide Inpatient Sample-SAH Outcome Measure, an externally-validated outcome measure combining death, discharge disposition, tracheostomy and/or gastrostomy. Regional variability in the associations between care and outcomes were assessed by introducing an interaction term for US region into the models.

Results

Of 109,034 patients included, 24.3% were from Northeast, 24.9% Midwest, 34.9% South, 15.9% West. Mean (SD) age was 58.6 (15.6) years and 64,245 (58.9%) were female. In-hospital mortality occurred in 21,991 (20.2%) and 44,159 (40.5%) had poor discharge outcome. There was significant variability in severity-of-illness, co-morbidities, complications and interventions across US regions. Notable findings were higher prevalence of surgical clipping (18.8 vs. 11.6%), delayed cerebral ischemia (4.3 vs. 3.1%), seizures (16.5 vs. 14.8%), infections (18 vs. 14.7%), length of stay (mean [SD] days; 15.7 [19.2] vs. 14.1 [16.7]) and health-care direct costs (mean [SD] USD; 80,379 [98,999]. vs. 58,264 [74,430]) in the West when compared to other regions (all p < 0.0001). Variability in care was also associated with modest variability in hospital mortality and discharge outcome. Aneurysm repair, nimodipine use, later admission-year, endovascular rescue therapies reduced the odds for poor outcome. Age, severity-of-illness, co-morbidities, hospital complications, and vasopressor use increased those odds (c-statistic; mortality: 0.77; discharge outcome: 0.81). Regional interaction effect was significant for admission severity-of-illness, aneurysm-repair and nimodipine-use.

Discussion

Multiple hospital-care factors impact SAH outcomes and significant variability in hospital-care and modest variability in discharge-outcomes exists across the US. Variability in SAH-severity, nimodipine-use and aneurysm-repair may drive variability in outcomes.

Association Between Hospital Volumes and Clinical Outcomes for Patients With Nontraumatic Subarachnoid Hemorrhage

Background

Previous studies of patients with nontraumatic subarachnoid hemorrhage (SAH) suggest better outcomes at hospitals with higher case and procedural volumes, but the shape of the volume‐outcome curve has not been defined. We sought to establish minimum volume criteria for SAH and aneurysm obliteration procedures that could be used for comprehensive stroke center certification.

Methods and Results

Data from 8512 discharges in the National Inpatient Sample (NIS) from 2010 to 2011 were analyzed using logistic regression models to evaluate the association between clinical outcomes (in‐hospital mortality and the NIS‐SAH Outcome Measure [NIS‐SOM]) and measures of hospital annual case volume (nontraumatic SAH discharges, coiling, and clipping procedures). Sensitivity and specificity analyses for the association of desirable outcomes with different volume thresholds were performed. During 8512 SAH hospitalizations, 28.7% of cases underwent clipping and 20.1% underwent coiling with rates of 21.2% for in‐hospital mortality and 38.6% for poor outcome on the NIS‐SOM. The mean (range) of SAH, coiling, and clipping annual case volumes were 30.9 (1–195), 8.7 (0–94), and 6.1 (0–69), respectively. Logistic regression demonstrated improved outcomes with increasing annual case volumes of SAH discharges and procedures for aneurysm obliteration, with attenuation of the benefit beyond 35 SAH cases/year. Analysis of sensitivity and specificity using different volume thresholds confirmed these results. Analysis of previously proposed volume thresholds, including those utilized as minimum standards for comprehensive stroke center certification, showed that hospitals with more than 35 SAH cases annually had consistently superior outcomes compared with hospitals with fewer cases, although some hospitals below this threshold had similar outcomes. The adjusted odds ratio demonstrating lower risk of poor outcomes with SAH annual case volume ≥35 compared with 20 to 34 was 0.82 for the NIS‐SOM (95% CI, 0.71–094; P=0.0054) and 0.80 (95% CI, 0.68–0.93; P=0.0055) for in‐hospital mortality.

Conclusions

Outcomes for patients with SAH improve with increasing hospital case volumes and procedure volumes, with consistently better outcomes for hospitals with more than 35 SAH cases per year.

Triage and systems of care in stroke

There has been increasing adoption of endovascular stroke treatment in the United States following multiple clinical trials demonstrating superior efficacy. Next steps in enhancing this treatment include an analysis and development of stroke systems of care geared toward efficient delivery of endovascular and comprehensive stroke care. The chapter presents epidemiological data and an overview of the current state of stroke delivery and potential improvements for the future in the light of clinical data.

Changes in Neuroendovascular Procedural Volume During the COVID-19 Pandemic: An International Multicenter Study

BACKGROUND AND PURPOSE

The effect of coronavirus disease 2019 (COVID‐19) pandemic on performance of neuroendovascular procedures has not been quantified.

METHODS

We performed an audit of performance of neuroendovascular procedures at 18 institutions (seven countries) for two periods; January‐April 2019 and 2020, to identify changes in various core procedures. We divided the region where the hospital was located based on the median value of total number of COVID‐19 cases per 100,00 population‐into high and low prevalent regions.

RESULTS

Between 2019 and 2020, there was a reduction in number of cerebral angiograms (30.9% reduction), mechanical thrombectomy (8% reduction), carotid artery stent placement for symptomatic (22.7% reduction) and asymptomatic (43.4% reduction) stenoses, intracranial angioplasty and/or stent placement (45% reduction), and endovascular treatment of unruptured intracranial aneurysms (44.6% reduction) and ruptured (22.9% reduction) and unruptured brain arteriovenous malformations (66.4% reduction). There was an increase in the treatment of ruptured intracranial aneurysms (10% increase) and other neuroendovascular procedures (34.9% increase). There was no relationship between procedural volume change and intuitional location in high or low COVID‐19 prevalent regions. The procedural volume reduction was mainly observed in March‐April 2020.

CONCLUSIONS

We provided an international multicenter view of changes in neuroendovascular practices to better understand the gaps in provision of care and identify individual procedures, which are susceptible to change.

Deep learning based detection of intracranial aneurysms on digital subtraction angiography: A feasibility study

BACKGROUND

Digital subtraction angiography is the gold standard for detecting and characterising aneurysms. Here, we assess the feasibility of commercial-grade deep learning software for the detection of intracranial aneurysms on whole-brain anteroposterior and lateral 2D digital subtraction angiography images.

MATERIAL AND METHODS

Seven hundred and six digital subtraction angiography images were included from a cohort of 240 patients (157 female, mean age 59 years, range 20-92; 83 male, mean age 55 years, range 19-83). Three hundred and thirty-five (47%) single frame anteroposterior and lateral images of a digital subtraction angiography series of 187 aneurysms (41 ruptured, 146 unruptured; average size 7±5.3 mm, range 1-5 mm; total 372 depicted aneurysms) and 371 (53%) aneurysm-negative study images were retrospectively analysed regarding the presence of intracranial aneurysms. The 2D data was split into testing and training sets in a ratio of 4:1 with 3D rotational digital subtraction angiography as gold standard. Supervised deep learning was performed using commercial-grade machine learning software (Cognex, ViDi Suite 2.0). Monte Carlo cross validation was performed.

RESULTS

Intracranial aneurysms were detected with a sensitivity of 79%, a specificity of 79%, a precision of 0.75, a F1 score of 0.77, and a mean area-under-the-curve of 0.76 (range 0.68-0.86) after Monte Carlo cross-validation, run 45 times.

CONCLUSION

The commercial-grade deep learning software allows for detection of intracranial aneurysms on whole-brain, 2D anteroposterior and lateral digital subtraction angiography images, with results being comparable to more specifically engineered deep learning techniques.

Initial Emergency Room Triage of Acute Ischemic Stroke

Early recognition and differentiation of acute ischemic stroke from intracranial hemorrhage and stroke mimics and the identification of large vessel occlusion (LVO) are critical to the appropriate management of stroke patients. In this review, we discuss the current evidence and practices surrounding safe and efficient triage in the emergency room. As the indications of stroke intervention are evolving to further improve stroke care, focus has begun to revolve around recognition of LVO and provision of endovascular thrombectomy with or without the administration of tissue plasminogen activator. Systems of stroke care are being organized to achieve this goal without delay. Clinical history is important in determining time of onset or last known well time, but, alone or along with an examination, it cannot reliably predict an LVO or exclude intracranial hemorrhage and stroke mimics. The choice of imaging is influenced mainly by the duration of symptoms. On the basis of recent trials, patients presenting after the 6-h therapeutic window can be considered for endovascular thrombectomy if the computed tomographic or magnetic resonance perfusion imaging shows favorable findings. The Society of NeuroInterventional Surgery has established time metrics for each step of triage and initial management. Hospitals are required to develop multidisciplinary stroke teams and emergency protocols to meet these goals. There also needs to be coordination of the emergency medical services with the emergency facility of an appropriate stroke center (a primary stroke center, comprehensive stroke care center, or a thrombectomy-capable stroke center).

Trends in hospital procedure volumes for intra-arterial treatment of acute ischemic stroke: results from the paul coverdell national acute stroke program

BACKGROUND

Rates of intra-arterial revascularization treatments (IAT) for acute ischemic stroke (AIS) are increasing in the USA. Using a multi-state stroke registry, we studied the trend in IAT use among patients with AIS over a period spanning 11 years. We examined the impact of IAT rates on hospital procedure volumes and patient outcome after stroke.

METHODS

We used data from the Paul Coverdell National Acute Stroke Program (PCNASP) and explored trends in IAT between 2008 and 2018. Patient outcomes were examined by rates of IAT procedures across hospitals. Specifically, outcomes were compared across low-volume (<15 IAT per year), medium-volume (15-30 IAT per year), and high-volume hospitals (>30 IAT per year). Favorable outcome was defined as discharge to home.

RESULTS

There were 612 958 patients admitted with AIS to 687 participating hospitals within the PCNASP during this study. Only 2.9% of patients (mean age 68.5 years, 49.3% women) received IAT. The percent of patients with AIS receiving IAT increased from 1% in 2008 to 5.3% in 2018 (p<0.001). The proportion of low-volume hospitals decreased over time (p<0.001), and the proportions of medium-volume (p=0.007) and high-volume hospitals (p<0.001) increased between 2008 and 2018. When compared with medium-volume hospitals, high-volume hospitals had a higher (p<0.0001) and low-volume hospitals had a lower (p<0.0001) percent of patients discharged to home.

CONCLUSION

High-volume hospitals were associated with a higher rate of favorable outcome. With the increased use of IAT among patients with AIS, the proportion of low-volume hospitals performing IAT significantly decreased.

Clinical Outcomes of Endovascular Thrombectomy in Tissue Plasminogen Activator versus Non-Tissue Plasminogen Activator Patients at Primary Stroke Care Centers

Background:

The effect of intravenous tissue plasminogen activator (IV tPA) administration before endovascular intervention as compared to without at thrombectomy-capable low-volume centers on procedural aspects and patient outcomes has not been investigated.

Methods:

Retrospective chart review was performed in all consecutive large vessel cerebrovascular accident patients treated with endovascular therapy at two select rural primary stroke centers between 2011 and 2015. Patients’ data regarding age, sex, and medical history, as well as thrombus location by catheter-based cerebral angiography, postprocedural reperfusion status, and clinical outcomes were reviewed. The primary outcome measure of the study was a comparison of modified Rankin scale (MRS) at 90 days in patients’ postendovascular thrombectomy with prior IV tPA administration versus those who underwent thrombectomy and did not qualify for preprocedural IV tPA.

Results:

After application of the set inclusion and exclusion criteria, data of 46 out of 65 patients were analyzed. Twenty-three patients (50%) received IV tPA before thrombectomy and 23 patients did not qualify for IV tPA (50%). Successful recanalization (thrombolysis in cerebral infarction 2b/3) was achieved in 86% (20/23 patients) of thrombectomy patients without preprocedural IV tPA and 82% (19/23) of patients who received it (odds ratio [OR]: 0.03, confidence interval [CI]: 95% 0.062–0.16, P < 0.0001). MRS of 2 or less at 90 days was 43.4% (10/23) in patients with no preprocedural IV tPA and 39.1% (9/23) in the combined therapy group (OR: 0.84, CI: 0.26–2.70, P = 0.8).

Conclusion:

Patients undergoing endovascular thrombectomy for large vessel occlusion at select low-volume rural centers showed benefit from this treatment regardless of IV tPA administration. Clinical outcomes and complications at select low-volume thrombectomy-proficient centers are comparable to large volume comprehensive stroke centers as well as the landmark studies proving the efficacy of endovascular treatment.

Neurointerventional Procedural Complications in a Growing Canadian Regional Stroke Center: Single Hospital Experience Analysis in the Context of Recommended Case Volumes

BACKGROUND

Evidence continues to emerge regarding the inverse relationship between high neurointerventional case volume and complication rates, leading several medical/surgical societies to recommend minimum volumes for specific procedures. Recent data suggest few centers are meeting these requirements. We report a single center's neurointerventional complication rates with associated case volumes, along with a review of the literature.

METHODS

A retrospective cohort review of all consecutive patients undergoing diagnostic catheter cerebral angiography and/or neurointerventional procedures between January 1, 2013, and March 1, 2018, was undertaken. No diagnostic or interventional procedures were excluded. All major and minor complications were recorded.

RESULTS

A total of 1000 procedures (463 diagnostic cerebral angiograms and 537 neurointerventional procedures) were completed. Of the neurointerventional procedures, 216 (40%) were endovascular thrombectomy, 170 (32%) were aneurysmal embolization, and 48 (9%) were carotid stenting. The mean and median age was 60 years. There were 460 women and 540 men. The total number of major complications for diagnostic angiography, endovascular thrombectomy, ruptured aneurysm embolization, unruptured aneurysm embolization, and carotid artery stenting were 4 (0.9%), 4 (1.9%), 10 (11%), 4 (5.4%), and 3 (6.3%), respectively.

CONCLUSIONS

We provided a single-center experience of the relationship between neurointerventional procedural case volume and complication rates in the growth phase of our center's establishment. We demonstrated that as our center was being developed, specific procedural staffing measures allowed proficiency maintenance, acquisition of new techniques, and complication avoidance, whereas specific case volumes crossed the suggested thresholds as defined in the literature.

Relationship between patient safety indicator events and comprehensive stroke center volume status in the treatment of unruptured cerebral aneurysms

OBJECTIVE

The Agency of Healthcare Research and Quality (AHRQ) has defined Patient Safety Indicators (PSIs) for assessments in quality of inpatient care. The hypothesis of this study is that, in the treatment of unruptured cerebral aneurysms (UCAs), PSI events are less likely to occur in hospitals meeting the volume thresholds defined by The Joint Commission for Comprehensive Stroke Center (CSC) certification.

METHODS

Using the 2002–2011 National (Nationwide) Inpatient Sample, patients treated electively for a nonruptured cerebral aneurysm were selected. Patients were evaluated for PSI events (e.g., pressure ulcers, retained surgical item, perioperative hemorrhage, pulmonary embolism, sepsis) defined by AHRQ-specified ICD-9 codes. Hospitals were categorized by treatment volume into CSC or non-CSC volume status based on The Joint Commission’s annual volume thresholds of at least 20 patients with subarachnoid hemorrhage and performance of 15 or more endovascular coiling or surgical clipping procedures for aneurysms.

RESULTS

A total of 65,824 patients underwent treatment for an unruptured cerebral aneurysm. There were 4818 patients (7.3%) in whom at least 1 PSI event occurred. The overall inpatient mortality rate was 0.7%. In patients with a PSI event, this rate increased to 7% compared with 0.2% in patients without a PSI event (p < 0.0001). The overall rate of poor outcome was 3.8%. In patients with a PSI event, this rate increased to 23.3% compared with 2.3% in patients without a PSI event (p < 0.0001). There were significant differences in PSI event, poor outcome, and mortality rates between non-CSC and CSC volume-status hospitals (PSI event, 8.4% vs 7.2%; poor outcome, 5.1% vs 3.6%; and mortality, 1% vs 0.6%). In multivariate analysis, all patients treated at a non-CSC volume-status hospital were more likely to suffer a PSI event with an OR of 1.2 (1.1–1.3). In patients who underwent surgery, this relationship was more substantial, with an OR of 1.4 (1.2–1.6). The relationship was not significant in the endovascularly treated patients.

CONCLUSIONS

In the treatment of unruptured cerebral aneurysms, PSI events occur relatively frequently and are associated with significant increases in morbidity and mortality. In patients treated at institutions achieving the volume thresholds for CSC certification, the likelihood of having a PSI event, and therefore the likelihood of poor outcome and mortality, was significantly decreased. These improvements are being driven by the improved outcomes in surgical patients, whereas outcomes and mortality in patients treated endovascularly were not sensitive to the CSC volume status of the hospital and showed no significant relationship with treatment volumes.

Indications for the Performance of Intracranial Endovascular Neurointerventional Procedures: A Scientific Statement From the American Heart Association

Intracranial endovascular interventions provide effective and minimally invasive treatment of a broad spectrum of diseases. This area of expertise has continued to gain both wider application and greater depth as new and better techniques are developed and as landmark clinical studies are performed to guide their use. Some of the greatest advances since the last American Heart Association scientific statement on this topic have been made in the treatment of ischemic stroke from large intracranial vessel occlusion, with more effective devices and large randomized clinical trials showing striking therapeutic benefit. The treatment of cerebral aneurysms has also seen substantial evolution, increasing the number of aneurysms that can be treated successfully with minimally invasive therapy. Endovascular therapies for such other diseases as arteriovenous malformations, dural arteriovenous fistulas, idiopathic intracranial hypertension, venous thrombosis, and neoplasms continue to improve. The purpose of the present document is to review current information on the efficacy and safety of procedures used for intracranial endovascular interventional treatment of cerebrovascular diseases and to summarize key aspects of best practice.

Reduced Patient Radiation Exposure during Neurodiagnostic and Interventional X-Ray Angiography with a New Imaging Platform

BACKGROUND AND PURPOSE

Advancements in medical device and imaging technology as well as accruing clinical evidence have accelerated the growth of the endovascular treatment of cerebrovascular diseases. However, the augmented role of these procedures raises concerns about the radiation dose to patients and operators. We evaluated patient doses from an x-ray imaging platform with radiation dose-reduction technology, which combined image noise reduction, motion correction, and contrast-dependent temporal averaging with optimized x-ray exposure settings.

MATERIALS AND METHODS

In this single-center, retrospective study, cumulative dose-area product inclusive of fluoroscopy, angiography, and 3D acquisitions for all neurovascular procedures performed during a 2-year period on the dose-reduction platform were compared with a reference platform. Key study features were the following: The neurointerventional radiologist could select the targeted dose reduction for each patient with the dose-reduction platform, and the statistical analyses included patient characteristics and the neurointerventional radiologist as covariates. The analyzed outcome measures were cumulative dose (kerma)-area product, fluoroscopy duration, and administered contrast volume.

RESULTS

A total of 1238 neurointerventional cases were included, of which 914 and 324 were performed on the reference and dose-reduction platforms, respectively. Over all diagnostic and neurointerventional procedures, the cumulative dose-area product was significantly reduced by 53.2% (mean reduction, 160.3 Gy × cm²; P < .0001), fluoroscopy duration was marginally significantly increased (mean increase, 5.2 minutes; P = .0491), and contrast volume was nonsignificantly increased (mean increase, 15.3 mL; P = .1616) with the dose-reduction platform.

CONCLUSIONS

A significant reduction in patient radiation dose is achievable during neurovascular procedures by using dose-reduction technology with a minimal impact on workflow.

Endovascular Treatment versus Best Medical Treatment in Patients with Acute Ischemic Stroke: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND PURPOSE

Endovascular treatment has emerged as a minimally invasive technique for patients with acute ischemic stroke to achieve recanalization. Our aim was to determine the effects of endovascular treatment on clinical and safety outcomes compared with best medical treatment.

MATERIALS AND METHODS

Fifteen randomized trials that compared endovascular treatment with best medical treatment in patients with acute ischemic stroke met the inclusion criteria. We calculated pooled odds ratios and 95% CIs by using random-effects models. The primary end point was a favorable outcome defined by a modified Rankin Scale score of 0 (no symptoms), 1 (no significant disability), or 2 (slight disability) at 90 days postrandomization.

RESULTS

Of the 2980 subjects randomized, the proportion of subjects who achieved a favorable outcome was significantly greater among those randomized to endovascular treatment compared with best medical treatment (2949 subjects analyzed; odds ratio, 1.82; 95% CI, 1.38-2.40; P < .001). Excellent outcome (modified Rankin Scale score of 0 or 1) was also significantly greater among those randomized to endovascular treatment (2791 subjects analyzed; odds ratio, 1.77; 95% CI, 1.29-2.43, P < .001). Risk of symptomatic intracranial hemorrhage was similar between endovascular treatment and best medical treatment (2906 subjects analyzed; odds ratio, 1.19; 95% CI, 0.84-1.68; P = .34).

CONCLUSIONS

Compared with best medical treatment, the odds of achieving a favorable outcome or excellent outcome at 3 months postrandomization are approximately 80% higher with endovascular treatment among patients with acute ischemic stroke.

Society of Vascular and Interventional Neurology (SVIN) Stroke Interventional Laboratory Consensus (SILC) Criteria: A 7M Management Approach to Developing a Stroke Interventional Laboratory in the Era of Stroke Thrombectomy for Large Vessel Occlusions

Brain attack care is rapidly evolving with cutting-edge stroke interventions similar to the growth of heart attack care with cardiac interventions in the last two decades. As the field of stroke intervention is growing exponentially globally, there is clearly an unmet need to standardize stroke interventional laboratories for safe, effective, and timely stroke care. Towards this goal, the Society of Vascular and Interventional Neurology (SVIN) Writing Committee has developed the Stroke Interventional Laboratory Consensus (SILC) criteria using a 7M management approach for the development and standardization of each stroke interventional laboratory within stroke centers. The SILC criteria include: (1) manpower: personnel including roles of medical and administrative directors, attending physicians, fellows, physician extenders, and all the key stakeholders in the stroke chain of survival; (2) machines: resources needed in terms of physical facilities, and angiography equipment; (3) materials: medical device inventory, medications, and angiography supplies; (4) methods: standardized protocols for stroke workflow optimization; (5) metrics (volume): existing credentialing criteria for facilities and stroke interventionalists; (6) metrics (quality): benchmarks for quality assurance; (7) metrics (safety): radiation and procedural safety practices.

Mechanical Thrombectomy Is Now the Gold Standard for Acute Ischemic Stroke: Implications for Routine Clinical Practice

BACKGROUND

This review aims to summarize the findings of the recently published randomized controlled studies which provide overwhelming evidence in support of mechanical thrombectomy for acute ischemic stroke with large artery occlusion. The five studies, Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN), Endovascular Revascularization with Solitaire Device versus Best Medical Therapy in Anterior Circulation Stroke within 8 h (REVASCAT), Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE), Solitaire™ FR as Primary Treatment for Acute Ischemic Stroke (SWIFT PRIME) and Extending the Time for Thrombolysis in Emergency Neurological Deficits with Intra-Arterial Therapy (EXTEND IA) have demonstrated the critical role of selecting patients by advanced neuroimaging, the superior recanalization capacity of stent retrievers and the effects of minimization of work processes delay.

SUMMARY

This review outlines lessons gained from the 5 positive studies which assessed mechanical thrombectomy as part of endovascular therapy for patients with proximal artery occlusion in the internal carotid and middle cerebral arteries. It discusses the role of age and stroke severity on treatment while also comparing the unique trial designs and selection criteria used amongst the 5 studies. In addition to examining the importance of unique imaging parameters such as collateral circulation, mismatch ratio and ischemic core volume, the review outlines differences in workflow parameters within the context of outcome. Finally the benefit of neuroimaging to broaden treatment eligibility and the issues associated with general anesthesia will be discussed in this review.

KEY MESSAGES

Questions remain over the applicability of mechanical thrombectomy to stroke subgroups including wake-up strokes and basilar artery thrombosis. The role of imaging is integral to this process and can lead to broadening eligibility criteria in the future. Workflow practices have been streamlined in the 5 positive randomized controlled studies, but guidelines will need to be revised accordingly if similar patient outcomes are to be replicated in a wider population.

Endovascular Clot Retrieval Therapy

Endovascular acute ischemic stroke therapy is now proven by randomized controlled trials to produce large, clinically meaningful benefits. In response, stroke systems of care must change to increase timely and equitable access to this therapy. In this review, we provide a North American perspective on implications for stroke systems, focusing on the United States and Canada, accompanied by initial recommendations for changes. Most urgently, every community must create access to a hospital that can safely and quickly provide intravenous tissue-type plasminogen activator and immediately transfer appropriate patients onward to a more capable center as required. Safe and effective therapy in the community setting will be ensured by certification programs, performance measurement, and data entry into registries.

An analysis of patients transferred to a tertiary oncological intensive care unit for defined procedures

BACKGROUND

Up to 50 000 intensive care unit interhospital transfers occur annually in the United States.

OBJECTIVE

To determine the prevalence, characteristics, and outcomes of cancer patients transferred from an intensive care unit in one hospital to another intensive care unit at an oncological center and to evaluate whether interventions planned before transfer were performed.

METHODS

Data on transfers for planned interventions from January 2008 through December 2012 were identified retrospectively. Demographic and clinical variables, receipt of planned interventions, and outcome data were analyzed.

RESULTS

Of 4625 admissions to an intensive care unit at the oncological center, 143 (3%) were transfers from intensive care units of other hospitals. Of these, 47 (33%) were transfers for planned interventions. Patients' mean age was 57 years, and 68% were men. At the time of intensive care unit transfer, 20 (43%) were receiving mechanical ventilation. Interventions included management of airway (n = 19) or gastrointestinal (n = 2) obstruction, treatment of tumor bleeding (n = 12), chemotherapy (n = 10), and other (n = 4). A total of 37 patients (79%) received the planned interventions within 48 hours of intensive care unit arrival; 10 (21%) did not because their signs and symptoms abated. Median intensive care unit and hospital lengths of stay at the oncological center were 4 and 13 days, respectively. Intensive care unit and hospital mortality rates were 11% and 19%, respectively. Deaths occurred only in patients who received interventions.

CONCLUSIONS

Interhospital transfers of cancer patients to an intensive care unit at an oncological center are infrequent but are most commonly done for direct interventional care. Most patients received planned interventions soon after transfer.

Effectiveness and safety of extracranial carotid stent placement: a nationwide self-controlled case-series study

BACKGROUND

Carotid angioplasty and stent (CAS) placement has emerged as an attractive revascularization strategy for patients with internal carotid artery stenosis. However, the effectiveness and safety of CAS were not fully evaluated, mainly because of methodological difficulties in finding an appropriate comparison group.

METHODS

Patients who underwent CAS were identified from Taiwan's National Health Insurance claims database between 2005 and 2008. The incidence rate of ischemic stroke after CAS was compared with that of the year prior to the procedure using a self-controlled case series analysis and a conditional Poisson regression model. Logistic regression was conducted to identify factors associated with poor outcome.

RESULTS

A total of 1258 patients who had undergone CAS were included, and 73 cases (5.8%) of death or ischemic stroke occurred during the index hospitalization. Within 1 year after CAS, 74 patients died and 80 experienced an ischemic stroke. Of the 1184 patients who were followed for 360 days, the rate ratio for ischemic stroke decreased to 0.21 (95% CI: 0.08-0.51) between 31 and 180 days, and 0.10 (95% CI: 0.03-0.32) between 181 and 360 days. Statin therapy was associated with a reduced risk of death or ischemic stroke in the 1(st) month (odds ratio of 0.53; 95% CI: 0.32-0.90). Conversely, the use of nonsteroidal anti-inflammatory agents, possibly histamine-2 receptor blockers, and CAS performed by low-volume operators were associated with a twofold increased risk.

CONCLUSION

CAS reduced the long-term risk for ischemic stroke. Self-controlled case series analysis might be an appropriate design for evaluating device safety and effectiveness.

US nationwide trends in carotid revascularization: is there a clinical opportunity cost associated with the introduction of novel medical devices?

OBJECTIVES

Nationwide practice patterns during the implementation of novel technology, such as carotid angioplasty and stenting (CAS) and embolic protection devices (EPD), and the clinical impact thereof have received less attention.

METHODS

The Nationwide Inpatient Sample, constituting a 20% representative sample of non-federal US hospitals, was analyzed from years 1998 to 2007. Hospital outcome was stratified into in-hospital mortality (IHM), long-term facility discharge, and home/ short-term facility discharge (HSF).

RESULTS

Discharge outcome improved for CAS over the decade. However, this improvement occurred in two phases with a period of worsening (2003-2005) in between. During this transition period, the risk of IHM following CAS was increased (RR 1.29-2.43) and was lower for good outcome (HSF: RR 0.97-0.99) when compared with 2002/2003. During the same transition period, carotid endarterectomy (CEA) was associated with a lower risk of IHM (RR 0.75-1.00), but also a lower risk of HSF (RR 0.98-0.99).

CONCLUSIONS

The results lead to the hypothesis that the nationwide introduction of CAS-EPD may have been associated with temporary increases in in-hospital mortality and discharge morbidity. If such 'clinical opportunity costs' exist with the widespread introduction and adoption of new medical technology with proven efficacy in randomized trials, effective mechanisms are needed for mitigation or prevention during the transition period.

Endovascular neurointervention success and complication rates in the first year of independent practice in a suburban hospital setup

CONTEXT

Endovascular neurointervention (interventional neuroradiology) is a highly demanding science requiring deep understanding of disease, anatomy, clinical skills and manual dexterity, consequently with a long learning curve and thus posing significant challenges to a physician entering new into the competitive arena.

AIM

To evaluate the procedural success, complications and outcome in the first year of independent endovascular neurointervention practice in a suburban hospital.

MATERIALS AND METHODS

Retrospective analysis of prospectively maintained data of all diagnostic and therapeutic neurointerventional cases performed by the author between the period of January 02, 2012 and December 31, 2012.

RESULTS

A total of 61 procedures were performed. The performance success rate of the diagnostic procedures was 100% (38/38) and that of therapeutic procedures was 82.6% (19/23). The periprocedural complication rates were nil and 13%, respectively, for diagnostic and therapeutic procedures. The 3-month patient outcome for therapeutic procedures was good outcome (Modified Rankin Scale <2) in 87% cases (20/23), and poor outcome in 13% (2 dead and 1 debilitated with Modified Rankin Scale of 3).

CONCLUSION

For a well-trained endovascular neurointerventionalist, the first year of practice had high procedural success rate and acceptable complication with patient outcome rates comparable to the existing literature.

Recent trends in neuroendovascular therapy in Japan: analysis of a nationwide survey--Japanese Registry of Neuroendovascular Therapy (JR-NET) 1 and 2

The present study retrospectively analyzed the database of the Japanese Registry of Neuroendovascular Therapy 1 and 2 (JR-NET1&2) to determine annual trends, including adverse events and clinical outcomes at 30 days after undergoing neuroendovascular therapy. JR-NET1&2 are surveys that targeted all patients in Japan who underwent neuroendovascular therapy delivered by physicians certified by the Japanese Society of Neuroendovascular Therapy (JSNET) between 2005 and 2009. Medical information about the patients was anonymized and retrospectively registered via a website. Data from 32,608 patients were analyzed. The number of treated patients constantly increased from 5,040 in 2005 to 7,406 in 2009 and the rate of octogenarians increased from 7.0% in 2005 to 10.4% in 2009. The proportion of procedures remained relatively constant, but ratios of angioplasty slightly increased from 32.8% in 2005 to 33.7% in 2009. Procedural complications were associated more frequently with acute stroke (9.6%), ruptured aneurysms (7.4%), intracranial artery disease (ICAD) (5.4%), and arteriovenous malformation (AVM, 5.2%). The number of patients requiring neuroendovascular treatment in Japan is increasing and the outcomes of such therapy are clinically acceptable. Details of each type of treatment will be investigated in sub-analyses of the database.

Mechanical thrombectomy with the Solitaire stent: is there a learning curve in achieving rapid recanalization times?

METHODS

In acute ischemic stroke, good outcome following successful recanalization is time dependent. In patients undergoing endovascular therapy at our institution, recanalization times with the Solitaire stent were retrospectively evaluated to assess for the presence of a learning curve in achieving rapid recanalization.

METHODS

We reviewed patients who presented to our stroke center and achieved successful recanalization with the Solitaire stent exclusively. Time intervals were calculated (CT to angiography arrival, angiography arrival to groin puncture, groin puncture to first deployment, and deployment to recanalization) from time stamped images and angiography records. Patients were divided into three sequential groups, with overall CT to recanalization time and subdivided time intervals compared.

RESULTS

83 patients were treated with the Solitaire stent from May 2009 to February 2012. Recanalization (Thrombolyis in Cerebral Infarction score 2A) occurred in 75 (90.4%) patients. CT to recanalization demonstrated significant improvement over time, which was greatest between the first 25 and the most recent 25 cases (161-94 min; p<0.01). The maximal contribution to this was from improvements in first stent deployment to recanalization time (p=0.001 between the first and third groups), with modest contributions from moving patients from CT to the angiography suite faster (p=0.02 between the first and third groups) and from groin puncture to first stent deployment (p=0.02 between the first and third groups).

CONCLUSIONS

There is a learning curve involved in the efficient use of the Solitaire stent in endovascular acute stroke therapy. Along with improvements in patient transfer to angiography and improved efficiency with intracranial access, mastering this device contributed significantly towards reducing recanalization times.

Racial and socioeconomic disparities in access to mechanical revascularization procedures for acute ischemic stroke

BACKGROUND

Mechanical revascularization procedures performed for treatment of acute ischemic stroke have increased in recent years. Data suggest association between operative volume and mortality rates. Understanding procedural allocation and patient access patterns is critical. Few studies have examined these demographics.

METHODS

Data were collected from the 2008 Nationwide Inpatient Sample database. Patients hospitalized with ischemic stroke and the subset of individuals who underwent mechanical thrombectomy were characterized by race, payer source, population density, and median wealth of the patient's zip code. Demographic data among patients undergoing mechanical thrombectomy procedures were examined. Stroke admission demographics were analyzed according to thrombectomy volume at admitting centers and patient demographics assessed according to the thrombectomy volume at treating centers.

RESULTS

Significant allocation differences with respect to frequency of mechanical thrombectomy procedures among stroke patients existed according to race, expected payer, population density, and wealth of the patient's zip code (P < .0001). White, Hispanic, and Asian/Pacific Islander patients received endovascular treatment at higher rates than black and Native American patients. Compared with the white stroke patients, black (P < .001), Hispanic (P < .001), Asian/Pacific Islander (P < .001), and Native American stroke patients (P < .001) all demonstrated decreased frequency of admission to hospitals performing mechanical thrombectomy procedures at high volumes. Among treated patients, blacks (P = .0876), Hispanics (P = .0335), and Asian/Pacific Islanders (P < .001) demonstrated decreased frequency in mechanical thrombectomy procedures performed at high-volume centers when compared with whites. While present, socioeconomic disparities were not as consistent or pronounced as racial differences.

CONCLUSIONS

We demonstrate variances in endovascular acute stroke treatment allocation according to racial and socioeconomic factors in 2008. Efforts should be made to monitor and address potential disparities in treatment utilization.

Size and anatomic location of ruptured intracranial aneurysms in patients with single and multiple aneurysms: a retrospective study from a single center

BACKGROUND AND PURPOSE

The difference in the relationship between the size of intracranial aneurysms (IAs) and their risk of rupture in patients with singe IAs versus those with multiple IAs is unclear. We sought to retrospectively analyze the size of ruptured IAs (RIAs) in patients with single and multiple IAs in order to study this relationship further.

METHODS

We retrospectively measured the size and location of RIAs in all patients who presented to our institute with an acute subarachnoid hemorrhage between 1 January 2005 and 31 December 2010. The IAs were classified by size into very small IAs or VSAs (≤3 mm), small IAs or SAs (>3 mm but ≤7 mm) and others (>7 mm).

RESULTS

379 patients (281 with a single IA, Group 1 and 98 with multiple IAs, Group 2) with 419 treated RIAs were included in the study. VSAs and SAs constituted the majority of RIAs in both groups (33.5% and 45.2% in Group 1 and 24.6% and 50.7% in Group 2) and the mean size of the RIAs was not different between the two groups. VSAs constituted almost two-thirds of all RIAs in certain locations whereas IAs > 7 mm in size did not constitute more than a third of the RIAs at any of the arterial locations.

CONCLUSIONS

The high incidence of VSAs, particularly in certain locations in both patient subgroups, suggests that current diagnostic, prognostic and therapeutic options in the management of IAs should be more tailored towards the management of these difficult-to-treat lesions.

Endovascular treatment for acute ischemic stroke

BACKGROUND

In patients with ischemic stroke, endovascular treatment results in a higher rate of recanalization of the affected cerebral artery than systemic intravenous thrombolytic therapy. However, comparison of the clinical efficacy of the two approaches is needed.

METHODS

We randomly assigned 362 patients with acute ischemic stroke, within 4.5 hours after onset, to endovascular therapy (intraarterial thrombolysis with recombinant tissue plasminogen activator [t-PA], mechanical clot disruption or retrieval, or a combination of these approaches) or intravenous t-PA. Treatments were to be given as soon as possible after randomization. The primary outcome was survival free of disability (defined as a modified Rankin score of 0 or 1 on a scale of 0 to 6, with 0 indicating no symptoms, 1 no clinically significant disability despite symptoms, and 6 death) at 3 months.

RESULTS

A total of 181 patients were assigned to receive endovascular therapy, and 181 intravenous t-PA. The median time from stroke onset to the start of treatment was 3.75 hours for endovascular therapy and 2.75 hours for intravenous t-PA (P<0.001). At 3 months, 55 patients in the endovascular-therapy group (30.4%) and 63 in the intravenous t-PA group (34.8%) were alive without disability (odds ratio adjusted for age, sex, stroke severity, and atrial fibrillation status at baseline, 0.71; 95% confidence interval, 0.44 to 1.14; P=0.16). Fatal or nonfatal symptomatic intracranial hemorrhage within 7 days occurred in 6% of the patients in each group, and there were no significant differences between groups in the rates of other serious adverse events or the case fatality rate.

CONCLUSIONS

The results of this trial in patients with acute ischemic stroke indicate that endovascular therapy is not superior to standard treatment with intravenous t-PA. (Funded by the Italian Medicines Agency, ClinicalTrials.gov number, NCT00640367.).

Treating the elderly stroke patient: complications, controversies, and best care metrics

Acute stroke is a devastating disease that affects almost 800,000 Americans annually. Worldwide, the incidence of stroke is rapidly increasing. Although stroke can affect all age groups, patients over age 80 are at much higher risk for ischemic stroke. Despite this, there are disparities in thrombolytic treatment rates, and as well as outcomes, between elderly stroke patients and their younger counterparts. This article discusses what is currently known about the elderly stroke patient for a greater understanding of the disease burden, research limitations and potential treatment options.

Mechanical thrombectomy in acute stroke: utilization variances and impact of procedural volume on inpatient mortality

BACKGROUND

An increasing number of endovascular mechanical thrombectomy procedures are being performed for the treatment of acute ischemic stroke. This study examines variances in the allocation of these procedures in the United States at the hospital level. We investigate operative volume across centers performing mechanical revascularization and establish that procedural volume is independently associated with inpatient mortality.

METHODS

Data was collected using the Nationwide Inpatient Sample database in the United States for 2008. Medical centers performing mechanical thrombectomy were identified using International Classification of Diseases, 9th revision codes, and procedural volumes were evaluated according to hospital size, location, control/ownership, geographic characteristics, and teaching status. Inpatient mortality was compared for hospitals performing ≥10 mechanical thrombectomy procedures versus those performing<10 procedures annually. After univariate analysis identified the factors that were significantly related to mortality, multivariable logistic regression was performed to compare mortality outcome by hospital procedure volume independent of covariates.

RESULTS

Significant allocation differences existed for mechanical thrombectomy procedures according to hospital size (P<.001), location (P<.0001), control/ownership (P<.0001), geography (P<.05), and teaching status (P<.0001). Substantial procedural volume was independently associated with decreased mortality (P=.0002; odds ratio 0.49) when adjusting for demographic covariates.

CONCLUSIONS

The number of mechanical thrombectomy procedures performed nationally remains relatively low, with a disproportionate distribution of neurointerventional centers in high-volume, urban teaching hospitals. Procedural volume is associated with mortality in facilities performing mechanical thrombectomy for acute ischemic stroke patients. These results suggest a potential benefit for treatment centralization to facilities with substantial operative volume.