Diagnostic imaging in the management of patients with possible cerebral venous thrombosis: a cost-effectiveness analysis.

PURPOSE: Imaging is crucial for management of patients with possible cerebral venous thrombosis (CVT). To evaluate the cost-effectiveness of different noninvasive imaging strategies in patients with possible CVT. METHODS: A decision model based on Markov simulations estimated lifetime costs and quality-adjusted life years (QALY) associated with the following imaging strategies: non-contrast CT (NCCT), NCCT plus CT venography (CTV), routine MRI without vascular imaging (R-MRI), and MRI with venography (MRV). The analysis was performed from a US healthcare perspective. Model input was based on best available and most recent evidence, including outcome data from the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT). Starting age was 37 years; both high and low pre-test probabilities of CVT were evaluated. Probabilistic sensitivity analyses (PSA) estimated model uncertainty. RESULTS: In the base-case analysis, NCCT and CTV were dominant over R-MRI and MRV. CTV led to incremental lifetime QALYs compared with NCCT (23.385 QALYs vs. 23.374 QALYs) at slightly higher lifetime costs ($5210 vs. $5057). In PSA, CTV was the strategy with the highest percentage of cost-effective iterations if willingness-to-pay (WTP) thresholds were higher than $13,750/QALY. Complying with contemporary WTP thresholds, CTV was thus identified as the most cost-effective strategy. When the pre-test probability was set to 50%, CTV was also preferred. CONCLUSION: In patients at the peak age of CVT incidence yet low clinical pre-test probability, diagnostic imaging with CTV is the most cost-effective strategy.

Screening for intracranial aneurysms in autosomal dominant polycystic kidney disease is cost-effective.

Intracranial aneurysm rupture is a dramatic complication of autosomal dominant polycystic kidney disease (ADPKD). It remains uncertain whether screening should be widespread or only target patients with risk factors (personal or familial history of intracranial aneurysm), with an at-risk profession, or those who request screening. We evaluated this in a single-center cohort of 495 consecutive patients with ADPKD submitted to targeted intracranial aneurysm screening. Cerebral magnetic resonance angiography was proposed to 110 patients with a familial history of intracranial aneurysm (group 1), whereas it was not our intention to propose it to 385 patients without familial risk (group 2). Magnetic resonance angiography results, intracranial aneurysm prophylactic repair, rupture events, and cost-effectiveness of intracranial aneurysm screening strategies were retrospectively analyzed. During a median follow up of 5.9 years, five non-fatal intracranial aneurysm ruptures occurred (incidence rate 2.0 (0.87-4.6)/1000 patients-year). In group 1, 90% of patients were screened and an intracranial aneurysm was detected in 14, treated preventively in five, and ruptured in one patient despite surveillance. In group 2, 21% of patients were screened and an intracranial aneurysm was detected in five, and treated preventively in one. Intracranial aneurysm rupture occurred in four patients in group 2. Systematic screening was deemed cost-effective and provides a gain of 0.68 quality-adjusted life years compared to targeted screening. Thus, the intracranial aneurysm rupture rate is high in ADPKD despite targeted screening, and involves mostly patients without familial risk factors. Hence, cost-utility analysis suggests that intracranial aneurysm screening could be proposed to all ADPKD patients.

Cost-effectiveness of angiographic imaging in isolated perimesencephalic subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: The purpose of this study is to perform a comprehensive cost-effectiveness analysis of all possible permutations of computed tomographic angiography (CTA) and digital subtraction angiography imaging strategies for both initial diagnosis and follow-up imaging in patients with perimesencephalic subarachnoid hemorrhage on noncontrast CT. METHODS: Each possible imaging strategy was evaluated in a decision tree created with TreeAge Pro Suite 2014, with parameters derived from a meta-analysis of 40 studies and literature values. Base case and sensitivity analyses were performed to assess the cost-effectiveness of each strategy. A Monte Carlo simulation was conducted with distributional variables to evaluate the robustness of the optimal strategy. RESULTS: The base case scenario showed performing initial CTA with no follow-up angiographic studies in patients with perimesencephalic subarachnoid hemorrhage to be the most cost-effective strategy ($5422/quality adjusted life year). Using a willingness-to-pay threshold of $50 000/quality adjusted life year, the most cost-effective strategy based on net monetary benefit is CTA with no follow-up when the sensitivity of initial CTA is >97.9%, and CTA with CTA follow-up otherwise. The Monte Carlo simulation reported CTA with no follow-up to be the optimal strategy at willingness-to-pay of $50 000 in 99.99% of the iterations. Digital subtraction angiography, whether at initial diagnosis or as part of follow-up imaging, is never the optimal strategy in our model. CONCLUSIONS: CTA without follow-up imaging is the optimal strategy for evaluation of patients with perimesencephalic subarachnoid hemorrhage when modern CT scanners and a strict definition of perimesencephalic subarachnoid hemorrhage are used. Digital subtraction angiography and follow-up imaging are not optimal as they carry complications and associated costs.

Clinical utility and cost-effectiveness of CT-angiography in the diagnosis of nontraumatic subarachnoid hemorrhage.

INTRODUCTION: CT-angiography gains an increasing role in the initial diagnosis of patients with nontraumatic subarachnoid hemorrhage (SAH). However, the implementation of CT-angiography does not always exclude the necessity of conventional angiography. Our objective was to determine the practical utility and cost-effectiveness of CT-angiography. METHODS: All patients with nontraumatic subarachnoid hemorrhage admitted to our university hospital after implementation of CT-angiography between June 1, 2011 and June 30, 2012 were retrospectively analyzed in regard to factors of treatment flow, radiation exposure, harms of contrast medium loading, and diagnostic costs. A control group of the same size was assembled from previously admitted SAH patients, who did not undergo pretreatment CT-angiography. Furthermore, cost-effectiveness analysis was performed. RESULTS: The final analysis consisted of 93 patients in each group. Of 93 patients with pretreatment CT-angiography, 74 had to undergo conventional angiography for diagnostic and/or therapeutic purposes. CT-angiography had significant impact on the reduction of collective effective radiation dose by 4.419 mSv per person (p = 0.0002) and was not associated with additional harms. Despite the significantly earlier detection of aneurysms with CT-angiography (p < 0.0001), there were no significant differences in the timing of aneurysm repair and duration of ICU and general hospital stay. There was an increase of diagnostic costs-the cost-effectiveness analysis showed, however, that benefits of CT-angiography in respect to radiation exposure and risk of conventional angiography-related complications justify the additional costs of CT-angiography. CONCLUSIONS: Although the implementation of CT-angiography in SAH diagnosis cannot completely replace conventional angiography, it can be approved in regard to radiation hygiene and cost-effectiveness.

Screening for blunt cerebrovascular injuries is cost-effective.

BACKGROUND: Screening for blunt carotid and vertebral injury (BCVI) is increasing without a clear understanding of whether the chosen screening approach is cost-effective. We hypothesized that screening for BCVI using computed tomography angiography (CTA) was cost-effective in populations at high risk for BCVI. METHODS: A decision analysis was performed modeling current BCVI screening approaches: no screening, duplex ultrasound, magnetic resonance angiography, angiography, and CTA. Treatment options included antiplatelet therapy, anticoagulation, stents for pseudoaneurysm, and no treatment. Probability estimates for incidence of injury and stroke, sensitivity and specificity of the screening modality, and type of treatment were taken from published data. Average wholesale price and medicare reimbursement costs were used. Two populations were analyzed; high-risk and overall blunt trauma populations. Two perspectives were taken; societal (including lifetime stroke costs) and institutional (ignoring lifetime stroke costs). RESULTS: In the high-risk population, from a societal perspective, CTA has the lowest cost and stroke rate; $3,727 per patient screened with a 1% stroke rate. No treatment has the highest cost and stroke rate. From an institutional perspective, no screening is the least costly option but has an 11% stroke rate. Duplex ultrasound is the most cost-effective screening modality; $8,940 per stroke prevented. CONCLUSION: From the societal perspective, CTA is the most cost-effective screening strategy for patients at high risk for BCVI. From an institutional perspective, CTA prevents the most strokes at a reasonable cost.

Cost-Effectiveness of Advanced Neuroimaging for Transient and Minor Neurological Events in the Emergency Department.

Background Accurate diagnosis of patients with transient or minor neurological events can be challenging. Recent studies suggest that advanced neuroimaging can improve diagnostic accuracy in low-risk patients with transient or minor neurological symptoms, but a cost-effective emergency department diagnostic evaluation strategy remains uncertain. Methods and Results We constructed a decision-analytic model to evaluate 2 diagnostic evaluation strategies for patients with low-risk transient or minor neurological symptoms: (1) obtain advanced neuroimaging (magnetic resonance imaging brain and magnetic resonance angiography head and neck) on every patient or (2) current emergency department standard-of-care clinical evaluation with basic neuroimaging. Main probability variables were: proportion of patients with true ischemic events, strategy specificity and sensitivity, and recurrent stroke rate. Direct healthcare costs were included. We calculated incremental cost-effectiveness ratios, conducted sensitivity analyses, and evaluated various diagnostic test parameters primarily using a 1-year time horizon. Cost-effectiveness standards would be met if the incremental cost-effectiveness ratio was less than willingness to pay. We defined willingness to pay as $100 000 US dollars per quality-adjusted life year. Our primary and sensitivity analyses found that the advanced neuroimaging strategy was more cost-effective than emergency department standard of care. The incremental effectiveness of the advanced neuroimaging strategy was slightly less than the standard-of-care strategy, but the standard-of-care strategy was more costly. Potentially superior diagnostic approaches to the modeled advanced neuroimaging strategy would have to be >92% specific, >70% sensitive, and cost less than or equal to standard-of-care strategy's cost. Conclusions Obtaining advanced neuroimaging on emergency department patient with low-risk transient or minor neurological symptoms was the more cost-effective strategy in our model.

Clinical feasibility of ultrafast intracranial vessel imaging with non-Cartesian spiral 3D time-of-flight MR angiography at 1.5T: An intra-individual comparison study.

OBJECTIVES: Non-Cartesian Spiral readout can be implemented in 3D Time-of-flight (TOF) MR angiography (MRA) with short acquisition times. In this intra-individual comparison study we evaluated the clinical feasibility of Spiral TOF MRA in comparison with compressed sensing accelerated TOF MRA at 1.5T for intracranial vessel imaging as it has yet to be determined. MATERIALS AND METHODS: Forty-four consecutive patients with suspected intracranial vascular disease were imaged with two Spiral 3D TOFs (Spiral, 0.82x0.82x1.2 mm3, 01:32 min; Spiral 0.8, 0.8x0.8x0.8 mm3, 02:12 min) and a Compressed SENSE accelerated 3D TOF (CS 3.5, 0.82x0.82x1.2 mm3, 03:06 min) at 1.5T. Two neuroradiologists assessed qualitative (visualization of central and peripheral vessels) and quantitative image quality (Contrast Ratio, CR) and performed lesion and variation assessment for all three TOFs in each patient. After the rating process, the readers were questioned and representative cases were reinspected in a non-blinded fashion. For statistical analysis, the Friedman and Nemenyi post-hoc test, Kendall W tests, repeated measure ANOVA and weighted Cohen's Kappa tests were used. RESULTS: The Spiral and Spiral 0.8 outperformed the CS 3.5 in terms of peripheral image quality (p<0.001) and performed equally well in terms of central image quality (p>0.05). The readers noted slight differences in the appearance of maximum intensity projection images. A good to high degree of interstudy agreement between the three TOFs was observed for lesion and variation assessment (W = 0.638, p<0.001 -W = 1, p<0.001). CR values did not differ significantly between the three TOFs (p = 0.534). Interreader agreement ranged from good (K = 0.638) to excellent (K = 1). CONCLUSIONS: Compared to the CS 3.5, both the Spiral and Spiral 0.8 exhibited comparable or better image quality and comparable diagnostic performance at much shorter acquisition times.

Screening for Intracranial Aneurysms in Coarctation of the Aorta: A Decision and Cost-Effectiveness Analysis.

BACKGROUND: Patients with coarctation of the aorta have a high prevalence of intracranial aneurysms (IA) and suffer subarachnoid hemorrhage (SAH) at younger ages than the general population. American Heart Association/American College of Cardiology guidelines recommend IA screening, but appropriate age and interval of screening and its effectiveness remain a critical knowledge gap. METHODS AND RESULTS: To evaluate the benefits and cost-effectiveness of magnetic resonance angiography screening for IA in patients with coarctation of the aorta, we developed and calibrated a Markov model to match published IA prevalence estimates. The primary outcome was the incremental cost-effectiveness ratio. Secondary outcomes included lifetime cumulative incidence of prophylactic IA treatment and mortality and SAH deaths prevented. Using a payer perspective, a lifetime horizon, and a willingness-to-pay of $150 000 per quality-adjusted life-year gained, we applied a 3% annual discounting rate to costs and effects and performed 1-way, 2-way, and probabilistic sensitivity analyses. In a simulated cohort of 10 000 patients, no screening resulted in a 10.1% lifetime incidence of SAH and 183 SAH-related deaths. Screening at ages 10, 20, and 30 years led to 978 prophylactic treatments for unruptured aneurysms, 19 procedure-related deaths, and 65 SAH-related deaths. Screening at ages 10, 20, and 30 years was cost-effective compared with screening at ages 10 and 20 years (incremental cost-effectiveness ratio $106 841/quality-adjusted life-year). Uncertainty in the outcome after aneurysm treatment and quality of life after SAH influenced the preferred screening strategy. In probabilistic sensitivity analysis, screening at ages 10, 20, and 30 years was cost-effective in 41% of simulations and at ages 10 and 20 in 59% of simulations. CONCLUSIONS: Our model supports the American Heart Association/American College of Cardiology recommendation to screen patients with coarctation of the aorta for IA and suggests screening at ages 10 and 20 or at 10, 20, and 30 years would extend life and be cost-effective.

Economic burden of intracranial vascular malformations in adults: prospective population-based study.

BACKGROUND AND PURPOSE: Although intracranial vascular malformations (IVMs) are the leading cause of intracerebral hemorrhage (ICH) in young adults, there has not been a cost-of-illness study on an unselected cohort. METHODS: We measured the direct healthcare costs (inpatient, outpatient, intervention, and brain imaging) incurred by every adult within 3 years after their first presentation with a brain arteriovenous malformation (AVM) or cavernous malformation (CM) in a prospective, population-based study. We estimated the indirect cost of lost productivity for the whole cohort over the same period by projecting questionnaire responses from living consenting adults. RESULTS: 369 adults (AVM=229 [62%], CM=140 [38%]) incurred healthcare costs of pound 5.96 million over 3 years, of which AVMs accounted for 90%, inpatient care accounted for 75%, and the first year of care accounted for 69%. Median 3-year healthcare costs were statistically significantly higher for adults presenting with ICH, aged <65 years, receiving interventional treatment, and adults with AVMs rather than CMs ( pound 15,784 versus pound 1385, P<0.0005). Healthcare costs diminished with increasing AVM nidus size (P=0.005). Mean 3-year costs of lost productivity per questionnaire respondent (n=145) were pound 17,111 for AVMs and pound 6752 for CMs (P=0.1), and the projected 3-year cost of lost productivity for all 369 adults was pound 8.7 million. CONCLUSIONS: The costs of healthcare and lost productivity attributable to IVMs are considerable, and highest in those aged <65 years, presenting with ICH, receiving interventional treatment, and harboring AVMs rather than CMs. Long-term studies of the cost-effectiveness of interventional treatment are needed.

Clinical results and costs of endovascular treatment in comparison with surgery in non ruptured aneurysms. / Resultados clínicos y de costes del tratamiento endovascular frente al quirúrgico en aneurismas incidentales.

OBJECTIVE: to evaluate the results and costs of surgical treatment against endovascular in non ruptured aneurysms. MATERIAL AND METHODS: retrospective study of a consecutive series non ruptured aneurysms from a single-center treated endovascularly (EV) and surgically (SC). A descriptive study of demographic (age, sex) charqacteristics of the patients and the radiological aspects of the aneurysms have been carried out. Clinical results (GOS at 6 months), angiographic data (occlusion classification) and economic costs have been evaluated in both globally, and in each of the groups. RESULTS: 89 patients treated between 2010 and 2015 were reviewed. Most of them were treated endovascularly (74%). There were no statiscally significant differences between EV and SC groups. 89% of the patients presented favourable GOS (4-5) at six months, being this percentage similar in both groups. Complete occlusion was much higher in SC group (96%) than in EV (55%). Retreatment rate was 24% in EV group and 0% in SC group. The retreatments were more frequent in anterior circulation aneurysms and bigger aneurysms (> 10 mm). The expenses in the SC group come mainly from hospital stay, meanwhile in the EV group is due to embolisation materials. The average length of stay (ALOS) are higher in SC group but costs of first admission are higher in EV group (14% more). When the costs of retreatments and follow up are included the costs of endovascular treatment is much higher than the surgical (61% more expensive). CONCLUSIONS: results of both types of treatment are comparable. The grade of aneurysmal occlusion of the SC group was higher than the EV, as well as the stability of the treatment, requiring fewer retreatments. Althoug the ALOS in SC group were longer, the costs of the EV group were significantly higher than the SC group due to the costs of embolisation materials, follow up that they need and the rate of retreatment. Adequate selection of candidates for endovascular coiling could improve angiographic outcomes, reduce retraction rates, and save costs.

Diagnostic value of multidetector-row CT angiography in the evaluation of thrombosis of the cerebral venous sinuses.

BACKGROUND AND PURPOSE: The diagnosis of cerebral venous and sinus thrombosis (CVST) as a rare but important cause of stroke is challenging. We aimed to investigate the diagnostic value of multidetector-row CT angiography (MDCTA) as a fast and cost-effective imaging tool in diagnosing CVST. MATERIALS AND METHODS: Nineteen patients who presented with clinical symptoms of a possible CVST were included. All patients had received both MDCTA and MR imaging with venous MR-angiography. Three blinded readers were asked to identify the cerebral sinuses and veins in MDCTA and to evaluate the presence of CVST in MDCTA. Consensus reading with interpretation of the MR imaging served to establish the definite diagnosis. RESULTS: The consensus reading revealed CVST in 10 of the 19 patients. With MDCTA, the venous sinuses could be identified in 99.2% and the cerebral veins in 87.6% of cases. The sensitivity and specificity of MDCTA for the diagnosis of CVST were 100%. CONCLUSION: Our study demonstrates that MDCTA provides excellent sensitivity and specificity for the diagnosis of CVST. Further studies are needed to evaluate the diagnostic potential of MDCTA in specific subsets of the general entity of CVST such as cortical venous thrombosis, thrombosis of the cavernous sinus, and thrombosis of the internal cerebral veins.

Cost-effectiveness analysis of CTA and LP for evaluation of suspected SAH after negative non-contrast CT.

OBJECTIVES: Diagnostic workup of patients presenting with thunderclap headache and negative initial head CT remains a challenge, with most commonly employed strategies being lumbar puncture (LP) and CT angiography (CTA). The objective of this study was to determine the cost-effectiveness of these options. PATIENTS AND METHODS: A decision model was designed using clinical probabilities, costs, and utilities from published values in the literature. Base case analysis and Monte Carlo simulation were performed using the model to determine the cost-effectiveness of both options. RESULTS: CTA was associated with an expected cost of $747 and an expected utility of 0.798603029. In comparison, LP was associated with a cost of $504 and an expected utility of 0.799259526, making it the optimal strategy from both the cost and the utility perspectives. LP was also the more cost-effective strategy in all iterations in the Monte Carlo simulation. A sensitivity analysis showed that with the 2014 US Medicare reimbursement values, LP would remain the more cost-effective strategy unless its cost exceeded 4 times its current value. CONCLUSION: LP should remain the preferred strategy for evaluation of SAH in patients presenting with thunderclap headache and negative non-contrast head CT. CTA is not an effective replacement, from either a utility or cost perspective.

Increased risk for complications following diagnostic cerebral angiography in older patients: Trends from the Nationwide Inpatient Sample (1999-2009).

The full utility of diagnostic cerebral angiography, an invasive cerebrovascular imaging technique, is currently debated. Our goal was to determine trends in diagnostic cerebral angiography utilization and associated complications from 1999 through 2009. The National Inpatient Sample (NIS) was used to identify patients who received primary cerebral angiography from 1999-2009 in the United States. We observed trends in discharge volume, total mean charge, and post-procedural complications for this population. Data was based on sample projections and analyzed using univariate and multivariate regression. There were a total of 424,105 discharges indicating primary cerebral angiography nationwide from 1999-2009. The majority of these cases (65%) were in patients older than 55years. Embolic stroke was the most frequent complication, particularly in the oldest age bracket, occurring in 16,304 patients. The risk for complications increased with age (p<0.0001) and with other underlying health conditions. Pulmonary, deep vein thrombosis, and renal associated comorbidities resulted in the greatest risk for developing post-procedural complications. Throughout the study period case volume for cerebral angiography remained constant while total charge per patient increased from $17,365 in 1999 to $45,339 in 2009 (p<0.001). While the overall complication rate for this invasive procedure is relatively low, the potential risk for embolic stroke in older patients is significant. It is worth considering less invasive diagnostic techniques for an older and at risk patient population.

Evaluation for Blunt Cerebrovascular Injury: Review of the Literature and a Cost-Effectiveness Analysis.

BACKGROUND AND PURPOSE: Evaluation for blunt cerebrovascular injury has generated immense controversy with wide variations in recommendations regarding the need for evaluation and the optimal imaging technique. We review the literature and determine the most cost-effective strategy for evaluating blunt cerebrovascular injury in trauma patients. MATERIALS AND METHODS: A comprehensive literature review was performed with data extracted to create a decision-tree analysis for 5 different strategies: anticoagulation for high-risk (based on the Denver screening criteria) patients, selective DSA or CTA (only high-risk patients), and DSA or CTA for all trauma patients. The economic evaluation was based on a health care payer perspective during a 1-year horizon. Statistical analyses were performed. The cost-effectiveness was compared through 2 main indicators: the incremental cost-effectiveness ratio and net monetary benefit. RESULTS: Selective anticoagulation in high-risk patients was shown to be the most cost-effective strategy, with the lowest cost and greatest effectiveness (an average cost of $21.08 and average quality-adjusted life year of 0.7231). Selective CTA has comparable utility and only a slightly higher cost (an average cost of $48.84 and average quality-adjusted life year of 0.7229). DSA, whether performed selectively or for all patients, was not optimal from both the cost and utility perspectives. Sensitivity analyses demonstrated these results to be robust for a wide range of parameter values. CONCLUSIONS: Selective CTA in high-risk patients is the optimal and cost-effective imaging strategy. It remains the dominant strategy over DSA, even assuming a low CTA sensitivity and irrespective of the proportion of patients at high-risk and the incidence of blunt cerebrovascular injury in high-risk patients.

Cost-effectiveness Analysis of Follow-up Strategies for Thunderclap Headache Patients With Negative Noncontrast CT.

OBJECTIVES: Accurate diagnosis of acute subarachnoid hemorrhage (SAH) is critical in thunderclap headache patients due to high morbidity and mortality associated with missed aneurysmal bleeds. The objective of this study was to determine the utility of computed tomography angiography (CTA) in managing patients with acute, severe headaches and negative noncontrast CT and assess the cost-effectiveness of three different screening strategies-no follow up, CTA, and lumbar puncture (LP). METHODS: A modeling-based economic evaluation was performed with a time horizon of 1 year for thunderclap headache patients in the emergency department with negative noncontrast CT for SAH. Sensitivity analyses were performed to determine the effect of sensitivity of CT and the prevalence of SAH on cost-effectiveness. RESULTS: Lumbar puncture follow-up has the lowest cost and the highest utility in the mathematical model. The Monte Carlo simulation shows noncontrast CT with LP follow-up to be the most cost-effective strategy in 85.3% of all cases even at a $1 million/quality-adjusted life-years willingness-to-pay. Sensitivity analyses demonstrate that LP follow-up should be performed, except for when CT sensitivity exceeds 99.2% and the SAH prevalence is below 3.2%, where no follow-up may be considered. CONCLUSIONS: Although CTA is frequently used for evaluation of thunderclap headache patients, its utility is not clearly defined. LP follow-up is shown to be the most cost-effective strategy for evaluation of thunderclap headache patients in most clinical settings.

Screening for blunt cerebrovascular injuries is cost-effective.

BACKGROUND: Recent reports have argued that screening for blunt carotid injury is futile and have called for a cost analysis. Our data previously supported screening asymptomatic trauma patients for blunt cerebrovascular injury (BCVI) to prevent associated neurologic sequelae. Our hypothesis is that aggressive angiographic screening for BCVI based on a patient's injury pattern and symptoms allows for early diagnosis and treatment and is cost-effective because it prevents ischemic neurological events (INEs). METHODS: Beginning in January 1996, we began comprehensive screening using 4-vessel cerebrovascular angiography based on injury patterns; these patients have been followed-up prospectively. Patients without contraindications received antithrombotic therapy immediately for documented BCVI. RESULTS: From January 1996 through June 2004, there were 15,767 blunt-trauma patient admissions to our state-designated level I urban trauma center, of which 727 patients underwent screening angiography. Twenty-one patients presented with signs or symptoms of neurologic ischemia before diagnosis. BCVI was identified in 244 patients (34% screening yield); the majority were men (68%) with a mean age of 35 +/- 3.7 years and mean Injury Severity Score of 28 +/- 3.8. Asymptomatic patients (n = 187) were treated (heparin in 117, low molecular-weight heparin in 11, and antiplatelet in 59); 1 patient had a stroke (0.5%). Using estimated stroke rate by grade of injury, we averted neurologic events in 32 asymptomatic patients with antithrombotic treatment. Of the 48 asymptomatic patients who did not receive adequate anticoagulation, 10 (21%) had an INE. Patients with BCVI-related neurologic events had a statistically higher percentage requiring discharge to rehabilitation facilities (50% vs. 77% for carotid artery injury [CAI]), a higher percentage requiring rehabilitation for BCVI-related stroke (0% vs. 55% for CAI), and a higher stroke-related mortality rate (0% vs. 21% for CAI and 0% vs. 17% for vertebral artery injury) than those without neurologic events. CONCLUSIONS: The cost of long-term rehabilitation care and human life after BCVI-associated neurologic events is substantial. Surgeons caring for the multiply injured should screen for carotid and vertebral artery injuries in high-risk patients.

Screening for Pediatric Blunt Cerebrovascular Injury: Review of Literature and a Cost-Effectiveness Analysis.

BACKGROUND: Timely and accurate screening for pediatric blunt cerebrovascular injury (BCVI) is important in order to administer appropriate anticoagulation therapy thus preventing stroke. The recommended criteria for screening in children are not clear. We performed a systematic review of the literature for screening and management of BCVI in children and designed a cost-effectiveness analysis in order to determine the optimal strategy for managing pediatric BCVI from a societal perspective. METHODS: Comprehensive review of studies citing BCVI in pediatric patients was carried out with data extraction and compilation. An economic evaluation of 5 possible screening strategies was performed by designing a decision tree over a 1-year horizon using parameters derived from literature review. Base case calculations were made to compare cost effectiveness for each strategy. Monte Carlo simulation and extensive sensitivity analyses were performed to examine the robustness of the conclusion against key variables. RESULTS: Selective anticoagulation therapy in patients with high-risk factors was found to be the most cost-effective strategy and selective computed tomography angiography (CTA) in high-risk patients was the optimal imaging strategy. This conclusion was corroborated by a Monte Carlo simulation of 10,000 iterations. In all sensitivity analyses, selective anticoagulation and selective CTA continue to be the optimal strategy until the risk of anticoagulation complications rises above 3.9%. CONCLUSIONS: Our study demonstrated selective CTA to be the optimal imaging strategy in order to assess BCVI in children. Further studies are needed for more clearly defined screening criteria.

Prospective series of two hours supine rest after 4fr sheath-based diagnostic cerebral angiography: Outcomes, productivity and cost.

There is no standard of care for catheter size or post-procedure supine time in cerebral angiography. Catheter sizes range from 4-Fr to 6-Fr with supine times ranging from two to over six hours. The objective of our study was to establish the efficacy, safety, and cost savings of two-hour supine time after 4-Fr elective cerebral angiography. A prospective, single arm study was performed on 107 patients undergoing elective cerebral angiography. All cerebral angiograms were performed with a 4-Fr sheath-based system without closure devices. Ten minutes of manual compression was applied to the femoral access site, with further compression held as clinically indicated. Patients were then monitored in a nursing unit for two hours supine and subsequently mobilized. Nursing discretion was allowed for earlier mobilization. Patients were called the next day to assess delayed hematoma and bleeding. Estimates of cost savings and productivity increases are provided. All patients ambulated in two hours or less. There were no strokes or vessel dissections. Five patients (4.7%) experienced a palpable hematoma, three patients (2.8%) experienced bleeding immediately following the procedure requiring further compression, and one patient (0.9%) experienced minor groin oozing at home. No patient required transfusion, thrombin injection, or endovascular/surgical management of a groin complication. A two-hour post-procedure supine time resulted in cost savings of $952 per angiogram and a total of $101,864. 4-Fr sheath based cerebral angiography with two-hour post-procedure supine time is safe and effective, and allows for a considerable increase in patient satisfaction, cost savings and productivity.

The Utility of Dual-Energy Computed Tomographic Angiography for the Evaluation of Brain Aneurysms After Surgical Clipping: A Prospective Study.

OBJECTIVE: The purpose of this prospective study was to compare a novel dual-energy computed tomographic angiography (DECTA) method for postoperative assessment of clipped brain aneurysms to detect aneurysm remnants and parent artery patency, with catheter-based digital subtraction angiography (DSA). METHODS: Patients who underwent microsurgical cerebral aneurysm repair were prospectively evaluated after surgery by both DECTA and conventional DSA. CTA was performed using a novel dual-energy method with single source and fast kilovoltage switching (Gemstone Spectral Imaging [GSI]). DSA was performed using biplanar cerebral angiography. An experienced neuroradiologist and a neurosurgeon, both blinded to the original radiologic results, reviewed the images. RESULTS: On DSA, 8 of 15 aneurysms (53%) had a remnant after clipping. All of these remnants were <2 mm except for 1. The only residual aneurysm >2 mm was clearly detected by GSI CTA. Of those 7 DSA-confirmed <2-mm remnants, 5 were detected by GSI CTA. Metal artifacts compromised the image quality in 2 patients. The sensitivity and specificity of GSI CTA for remnant aneurysm <2-mm detection in single clip-treated patients were 100%. In all patients, these were 71.4 % and 100%, respectively. GSI CTA was 100% sensitive and 77% specific to detect parent vessel compromise, with associated positive and negative predictive values of 60% and 100%, respectively. CONCLUSIONS: DECTA is a promising noninvasive alternative to conventional catheter-based angiography for identification of aneurysm remnants and assessment of adjacent arteries after surgical clipping of brain aneurysms treated by 2 or fewer clips. It allows for a more rapid image acquisition than DSA, is more cost effective, and is widely available at clinical centers.