Increased volumes of mildly elevated capillary transit time heterogeneity positively predict favorable outcome and negatively predict intracranial hemorrhage in acute ischemic stroke with large vessel occlusion.

OBJECTIVES: In patients with acute ischemic stroke, we aimed to investigate whether microvascular changes, as indexed by capillary transit time heterogeneity (CTH), contribute to the decline of the chance for favorable outcome over time and whether they are a predictor of an intracranial hemorrhage (ICH). METHODS: We retrospectively calculated CTH maps for 131 consecutive patients with acute ischemic stroke due to large vessel occlusion of the anterior circulation who had a relevant MRI PWI-DWI mismatch and were treated with endovascular thrombectomy (ET). Multivariable logistic regressions were conducted with favorable outcome (mRS ≤ 2 after 3 months) and occurrence of an ICH as dependent variables and the volume of mildly elevated CTH as independent variable adjusted for age, successful recanalization, hypertension, diabetes, atrial fibrillation, NIHSS score on admission, DWI lesion volume, and symptom-onset-to-treatment time (OTT). RESULTS: A larger volume of mildly elevated CTH was a positive predictor of favorable outcome (OR 1.17; 1.03-1.33; p = 0.019) and a negative predictor of ICH (OR 0.83; 0.73-0.96; p = 0.009). As expected, successful recanalization (OR 5.54; 1.8-17; p = 0.003), low NIHSS on admission (OR 0.9; 0.82-1.00; p = 0.045), short OTT (OR 0.96; 0.94-0.99; p = 0.006), and low DWI volume (OR 0.68; 0.49-0.94; p = 0.021) were also predictors of favorable outcome, whereas other negative predictors of ICH were atrial fibrillation (OR 2.69; 1.10-6.57; p = 0.030), high NIHSS score on admission (OR 1.10 (1.01-1.19); p = 0.030), and large DWI volume (OR 1.51; 1.17-1.19; p = 0.002). CONCLUSION: An increased volume of mildly elevated CTH is a positive predictor of favorable outcome and a negative predictor for ICH in patients with acute ischemic stroke and mismatch undergoing ET. KEY POINTS: • The classification of potentially salvageable tissue and infarct core based on traditional net perfusion parameters (as Tmax or CBF) does not account for the microvascular distribution of blood. • However, the microvascular distribution of blood, as indexed by the capillary transit time heterogeneity (CTH), directly affects the availability of oxygen within the hypoperfused tissue and should therefore be respected in acute ischemic stroke imaging. • In our study, mildly elevated CTH is found to be a positive predictor for a favorable clinical outcome and a negative predictor for the occurrence of an intracranial hemorrhage in patients with acute ischemic stroke and homogenous mismatch who underwent ET.

Clinical Outcome after Thrombectomy in Patients with Stroke with Premorbid Modified Rankin Scale Scores of 3 and 4: A Cohort Study with 136 Patients.

BACKGROUND AND PURPOSE: We aimed to analyze the clinical outcome after mechanical thrombectomy in patients with premorbid mRS 3 and 4 because there are currently no data on this patient group. MATERIALS AND METHODS: Between January 2009 and November 2017, all patients with premorbid mRS 3 or 4 undergoing mechanical thrombectomy due to anterior circulation stroke were selected. Good outcome was defined as a clinical recovery to the status before stroke onset (ie, equal premorbid mRS and mRS at 90 days). In addition, mortality at discharge and at 90 days was analyzed. RESULTS: One hundred thirty-six patients were included, of whom 81.6% presented with premorbid mRS 3; and 18.4%, with premorbid mRS 4; 24.0% of patients with premorbid mRS 4 achieved clinical recovery compared with 20.7% of patients with premorbid mRS 3 (P = .788). However, the proportion of hospital mortality and mortality at 90 days was nonsignificant, but markedly higher in patients with premorbid mRS 4. Multivariate analysis identified low NIHSS scores (OR, 0.92; 95% CI, 0.85-0.99; P = .040), high ASPECTS (OR, 1.45; 95% CI, 1.02-2.16; P = .049), and TICI 2b-3 (OR, 7.11; 95% CI, 1.73-49.90; P = .017) as independent predictors of good outcome. CONCLUSIONS: Good outcome in patients with premorbid mRS 3 and 4 is less frequent compared with premorbid mRS 0-2. Nevertheless, about 20% of the patients return to their premorbid mRS, which may justify endovascular treatment. The most important predictor of good outcome is successful recanalization.

Value of Contrast-Enhanced MRA versus Time-of-Flight MRA in Acute Ischemic Stroke MRI.

BACKGROUND AND PURPOSE: Vessel imaging in acute ischemic stroke is essential to select patients with large-vessel occlusion for mechanical thrombectomy. Our aim was to compare the diagnostic accuracy of time-of-flight MR angiography and contrast-enhanced MR angiography for identification of vessel occlusion and collateral status in acute ischemic stroke. MATERIALS AND METHODS: One hundred twenty-three patients with stroke with large-vessel occlusion before thrombectomy were included in this retrospective study. Before thrombectomy, 3T MR imaging, including conventional 3D TOF-MRA of the intracranial arteries and contrast-enhanced MRA of intra- and extracranial arteries, was performed. Both techniques were assessed independently by 2 neuroradiologists for location of the occlusion, imaging quality, and collateral status. Findings were compared, with subsequent DSA as the reference standard. RESULTS: Both techniques had good interrater agreement of κ = 0.74 (95% CI, 0.66-0.83) for TOF-MRA and κ = 0.72 (95% CI, 0.63-0.80) for contrast-enhanced MRA. Occlusion localization differed significantly on TOF-MRA compared with DSA (P < .001), while no significant difference was observed between DSA and contrast-enhanced MRA (P = .75). Assessment of collaterals showed very good agreement between contrast-enhanced MRA and DSA (94.9% with P = .25), but only fair agreement between TOF-MRA and DSA (23.2% with P < .001). CONCLUSIONS: Contrast-enhanced MRA offers better diagnostic accuracy than TOF-MRA in acute ischemic stroke. Contrast-enhanced MRA was superior in localizing vessel occlusion within a shorter acquisition time while providing a larger coverage, including extracranial vessels, and a more accurate assessment of collateral status. These results support inclusion of contrast-enhanced MRA in acute stroke MR imaging, perhaps making TOF-MRA superfluous.

First Experiences with the New Enterprise2® Stent.

INTRODUCTION: Stent-assisted coiling of wide-necked intracranial aneurysms has become an established treatment and has significantly benefited from the introduction of compliant, self-expanding devices, such as the Enterprise VRD (EP-VRD). We report our experiences with the successor model, the Enterprise2 (EP2) stent in stent-assisted coiling as well as in the treatment of atherosclerotic stenosis. MATERIALS AND METHODS: In 11 consecutive patients 12 EP2 were used to treat 9 intracranial aneurysms and 2 stenoses. RESULTS: All stents could easily be delivered including partial or complete recapturing when necessary. In two cases with sharp angled curves in the carotid siphon there was kinking and flattening of the stent resulting in incomplete wall apposition of the stent. Moreover, when vascular anatomy showed curves with angles >50° it was regularly observed that the proximal stent markers were asymmetrically arranged along the vessel circumference without influence on the stent apposition. Both findings could be reproduced in a silicone flow model. CONCLUSION: The EP2 performed well in our small patient cohort; however, above a critical acute angle there may be incomplete wall apposition of the stent.

The pCONus Device in Treatment of Wide-necked Aneurysms : Technical and Midterm Clinical and Angiographic Results.

PURPOSE: A variety of devices for treatment of wide-necked bifurcation aneurysms are emerging. Here we report our results using the new pCONus device with special emphasis on the morphological and anatomical requirements for successful implantation. METHODS: In this study we treated 21 patients with 22 aneurysms by endovascular interventions. After providing informed consent, patients were included according to the following criteria: aneurysm dome to neck ratio <2 or neck diameter >4 mm. The primary end points for clinical safety were the absence of death, absence of major or minor stroke and absence of transient ischemic attack. RESULTS: A total of 22 aneurysms in 21 patients were treated with pCONus-assisted coiling. In 19 patients harboring 20 aneurysms the implantation of the device was successful and these aneurysms showed an adequate occlusion after 6 months in 95 %. The complication rate was low (5 %) with one case of minor neurological stroke. Analysis of the data showed that the difference in aneurysm angulation between successful (mean 45°) and failed implantations (mean 71.5°) was highly significant. CONCLUSION: Use of the pCONus device and coiling in wide-necked bifurcation aneurysms is safe and provides good occlusion rates but might be limited by the angulation between the aneurysm and the parent vessel.

The Impact of Conscious Sedation versus General Anesthesia for Stroke Thrombectomy on the Predictive Value of Collateral Status: A Post Hoc Analysis of the SIESTA Trial.

BACKGROUND AND PURPOSE: Radiologic selection criteria to identify patients likely to benefit from endovascular stroke treatment are still controversial. In this post hoc analysis of the recent randomized Sedation versus Intubation for Endovascular Stroke TreAtment (SIESTA) trial, we aimed to investigate the impact of sedation mode (conscious sedation versus general anesthesia) on the predictive value of collateral status. MATERIALS AND METHODS: Using imaging data from SIESTA, we assessed collateral status with the collateral score of Tan et al and graded it from absent to good collaterals (0-3). We examined the association of collateral status with 24-hour improvement of the NIHSS score, infarct volume, and mRS at 3 months according to the sedation regimen. RESULTS: In a cohort of 104 patients, the NIHSS score improved significantly in patients with moderate or good collaterals (2-3) compared with patients with no or poor collaterals (0-1) (P = .011; mean, -5.8 ± 7.6 versus -1.1 ± 10.7). Tan 2-3 was also associated with significantly higher ASPECTS before endovascular stroke treatment (median, 9 versus 7; P < .001) and smaller mean infarct size after endovascular stroke treatment (median, 35.0 versus 107.4; P < .001). When we differentiated the population according to collateral status (0.1 versus 2.3), the sedation modes conscious sedation and general anesthesia were not associated with significant differences in the predictive value of collateral status regarding infarction size or functional outcome. CONCLUSIONS: The sedation mode, conscious sedation or general anesthesia, did not influence the predictive value of collaterals in patients with large-vessel occlusion anterior circulation stroke undergoing thrombectomy in the SIESTA trial.

e-ASPECTS Correlates with and Is Predictive of Outcome after Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: The e-ASPECTS software is a tool for the automated use of ASPECTS. Our aim was to analyze whether baseline e-ASPECT scores correlate with outcome after mechanical thrombectomy. MATERIALS AND METHODS: Patients with ischemic strokes in the anterior circulation who were admitted between 2010 and 2015, diagnosed by CT, and received mechanical thrombectomy were included. The ASPECTS on baseline CT was scored by e-ASPECTS and 3 expert raters, and interclass correlation coefficients were calculated. The e-ASPECTS was correlated with functional outcome (modified Rankin Scale) at 3 months by using the Spearman rank correlation coefficient. Unfavorable outcome was defined as mRS 4-6 at 3 months, and a poor scan was defined as e-ASPECTS 0-5. RESULTS: Two hundred twenty patients were included, and 147 (67%) were treated with bridging protocols. The median e-ASPECTS was 9 (interquartile range, 8-10). Intraclass correlation coefficients between e-ASPECTS and raters were 0.72, 0.74, and 0.76 (all, P < .001). e-ASPECTS (Spearman rank correlation coefficient = -0.15, P = .027) correlated with mRS at 3 months. Patients with unfavorable outcome had lower e-ASPECTS (median, 8; interquartile range, 7-10 versus median, 9; interquartile range, 8-10; P = .014). Sixteen patients (7.4%) had a poor scan, which was associated with unfavorable outcome (OR, 13.6; 95% CI, 1.8-104). Independent predictors of unfavorable outcome were e-ASPECTS (OR, 0.79; 95% CI, 0.63-0.99), blood sugar (OR, 1.01; 95% CI, 1.004-1.02), atrial fibrillation (OR, 2.64; 95% CI, 1.22-5.69), premorbid mRS (OR, 1.77; 95% CI, 1.21-2.58), NIHSS (OR, 1.11; 95% CI, 1.04-1.19), general anesthesia (OR, 0.24; 95% CI, 0.07-0.84), failed recanalization (OR, 8.47; 95% CI, 3.5-20.2), and symptomatic intracerebral hemorrhage (OR, 25.8; 95% CI, 2.5-268). CONCLUSIONS: The e-ASPECTS correlated with mRS at 3 months and was predictive of unfavorable outcome after mechanical thrombectomy, but further studies in patients with poor scan are needed.

Correlation of Thrombectomy Maneuver Count with Recanalization Success and Clinical Outcome in Patients with Ischemic Stroke.

BACKGROUND AND PURPOSE: In the treatment of acute thromboembolic stroke, the effectiveness and success of thrombus removal when using stent retrievers is variable. In this study, we analyzed the correlation of thrombectomy maneuver count with a good clinical outcome and recanalization success. MATERIALS AND METHODS: One hundred and four patients with acute occlusion of the middle cerebral artery or the terminal internal carotid artery who were treated with thrombectomy were included in this retrospective study. A good clinical outcome was defined as a 90-day mRS of ≤2, and successful recanalization was defined as TICI 2b-3. RESULTS: The maneuver count ranged between 1-10, with a median of 2. Multivariate logistic regression analyses identified an increasing number of thrombectomy maneuvers as an independent predictor of poor outcome (adjusted OR, 0.59; 95% CI, 0.38-0.87; P = .011) and unsuccessful recanalization (adjusted OR, 0.48; 95% CI, 0.32-0.66; P < .001). A good outcome was significantly more likely if finished within 2 maneuvers compared with 3 or 4 maneuvers, or even more than 4 maneuvers (P < .001). CONCLUSIONS: An increasing maneuver count correlates strongly with a decreasing probability of both good outcome and recanalization. The probability of successful recanalization decreases below 50% if not achieved within 5 thrombectomy maneuvers. Patients who are recanalized within 2 maneuvers have the best chance of achieving a good clinical outcome.

Liquid Embolic Agents for Endovascular Embolization: Evaluation of an Established (Onyx) and a Novel (PHIL) Embolic Agent in an In Vitro AVM Model.

BACKGROUND AND PURPOSE: Embolization plays a key role in the treatment of arteriovenous malformations. The aim of this study was to evaluate an established (Onyx) and a novel (precipitating hydrophobic injectable liquid [PHIL]) liquid embolic agent in an in vitro AVM model. MATERIALS AND METHODS: An AVM model was integrated into a circuit system. The artificial nidus (subdivided into 28 honeycomb-like sections) was embolized with Onyx 18 (group Onyx; n = 8) or PHIL 25 (group PHIL; n = 8) with different pause times between the injections (30 and 60 seconds, n = 4 per study group) by using a 1.3F microcatheter. Procedure times, number of injections, embolization success (defined as the number of filled sections of the artificial nidus), volume of embolic agent, and frequency and extent of reflux and draining vein embolization were assessed. RESULTS: Embolization success was comparable between Onyx and PHIL. Shorter pause times resulted in a significantly higher embolization success for PHIL (median embolization score, 28 versus 18; P = .011). Compared with Onyx, lower volumes of PHIL were required for the same extent of embolization (median volume per section of the artificial nidus, 15.5 versus 3.6 µL; P < .001). CONCLUSIONS: While the embolization success was comparable for Onyx and PHIL, pause time had a considerable effect on the embolization success in an in vitro AVM model. Compared with Onyx, lower volumes of PHIL were required for the same extent of embolization.

Minor Stroke Syndromes in Large-Vessel Occlusions: Mechanical Thrombectomy or Thrombolysis Only?

While mechanical thrombectomy for large-vessel occlusions is now an evidence-based treatment, its efficacy and safety in minor stroke syndromes (NIHSS ≤ 5) is not proved. We identified, in our prospective data base, 378 patients with minor strokes in the anterior circulation; 54 (14.2%) of these had proved large-vessel occlusions. Eight of 54 (14.8%) were immediately treated with mechanical thrombectomy, 6/54 (11.1%) after early neurologic deterioration, and the rest were treated with standard thrombolysis only. Rates of successful recanalization were similar between the 2 mechanical thrombectomy groups (75% versus 100%). Rates of excellent outcome (modified Rankin Scale 0-1) were higher in patients with immediate thrombectomy (75%) compared with patients with delayed thrombectomy (33.3%) and thrombolysis only (55%). No symptomatic intracranial hemorrhage occurred in either group. These descriptive data are encouraging, and further analysis of large registries or even randomized controlled trials in this patient subgroup should be performed.

Peri-procedural silent cerebral infarcts after left atrial appendage occlusion.

BACKGROUND AND PURPOSE: To determine the rate of peri-interventional silent brain infarcts after left atrial appendage occlusion (LAAO). METHODS: In this prospective, uncontrolled single-center pilot study, consecutive patients with atrial fibrillation undergoing LAAO between July 2013 and January 2016 were included. The Amplatzer Cardiac Plug, WATCHMAN or Amulet device was used. A neurological examination and cranial magnetic resonance imaging (MRI) were performed within 48 h before and after the procedure. MRI was evaluated for new diffusion-weighted imaging (DWI) hyperintensities, cerebral microbleeds (CMBs) and white-matter lesions (WMLs). RESULTS: Left atrial appendage occlusion was performed in 21 patients (mean age, 73.2 ± 9.5 years). Main reasons for LAAO were previous intracerebral hemorrhage (n = 11) and major systemic bleeding (n = 6). No clinically overt stroke occurred peri-interventionally. After the intervention, one patient had a small cerebellar hyperintensity on DWI (4.8%; 95% confidence interval, 0.0-14.3) that was not present on the MRI 1 day before the procedure. Among 11 patients with available MRI just before LAAO, there were no significant changes in the number of CMBs and the severity of WMLs after LAAO. CONCLUSIONS: This study of peri-interventional MRI in LAAO suggests a low rate of silent peri-procedural infarcts in this elderly population. Confirmation in larger studies is needed.

Clinical Outcome After Mechanical Thrombectomy in Non-elderly Patients with Acute Ischemic Stroke in the Anterior Circulation: Primary Admission Versus Patients Referred from Remote Hospitals.

BACKGROUND AND PURPOSE: Stroke networks have been installed to increase access to advanced stroke specific treatments like mechanical thrombectomy (MT). This concept often requires patients to be transferred to a comprehensive stroke center (CSC) offering MT. Do patient referral, transportation, and logistic effort translate into clinical outcomes comparable to patients admitted primarily to the CSC? MATERIAL AND METHODS: We categorized 112 patients with acute ischemic stroke in the anterior circulation, who received MT at our institution, into primary admissions (A) and referrals from either local (B) or regional (C) hospitals, assessed the clinical outcome, and tested the impact of distance and delay of transportation from the referring remote hospital. RESULTS: The median time from symptom onset to initial CT was similar in all groups (p = 0,939). Patients who were transferred to the CSC had significantly increasing median time between initial CT and MT (in minutes (interquartile range [IQR]); A: 83 [68-120]; B: 174 [159-208]; C: 220 [181-235]; p < 0.001) and median time between onset to MT (in minutes [IQR]; A: 178 [150-210]; B: 274 [238-349]; C: 293 [256-329]; p < 0.001). After 90 days of MT there was no significant difference in clinical outcome (modified Rankin Scale ≤ 2) between primary admitted and referred patients (p = 0.502). CONCLUSION: Clinical outcome in patients who received MT after transfer from either local or regional remote hospitals was not significantly worse than in patients primarily admitted to the CSC. In the event of an acute ischemic stroke patients living in urban or rural areas should, despite a possible delay, have access to MT.

Endovascular Stroke Treatment of Nonagenarians.

BACKGROUND AND PURPOSE: Although endovascular treatment has become a standard therapy in patients with acute stroke, the benefit for very old patients remains uncertain. The purpose of this study was the evaluation of procedural and outcome data of patients ≥90 years undergoing endovascular stroke treatment. MATERIALS AND METHODS: We retrospectively analyzed prospectively collected data of patients ≥90 years in whom endovascular stroke treatment was performed between January 2011 and January 2016. Recanalization was assessed according to the TICI score. The clinical condition was evaluated on admission (NIHSS, prestroke mRS), at discharge (NIHSS), and after 3 months (mRS). RESULTS: Twenty-nine patients met the inclusion criteria for this analysis. The median prestroke mRS was 2. Successful recanalization (TICI ≥ 2b) was achieved in 22 patients (75.9%). In 9 patients, an NIHSS improvement ≥ 10 points was noted between admission and discharge. After 3 months, 17.2% of the patients had an mRS of 0-2 or exhibited prestroke mRS, and 24.1% achieved mRS 0-3. Mortality rate was 44.8%. There was only 1 minor procedure-related complication (small SAH without clinical sequelae). CONCLUSIONS: Despite high mortality rates and only moderate overall outcome, 17.2% of the patients achieved mRS 0-2 or prestroke mRS, and no serious procedure-related complications occurred. Therefore, very high age should not per se be an exclusion criterion for endovascular stroke treatment.

Mechanical Thrombectomy in Patients with Acute Ischemic Stroke and Lower NIHSS Scores: Recanalization Rates, Periprocedural Complications, and Clinical Outcome.

BACKGROUND AND PURPOSE: Mechanical thrombectomy, in addition to intravenous thrombolysis, has become standard in acute ischemic stroke treatment in patients with large-vessel occlusion in the anterior circulation. However, previous randomized controlled stroke trials were not focused on patients with mild-to-moderate symptoms. Thus, there are limited data for patient selection, prediction of clinical outcome, and occurrence of complications in this patient population. The purpose of this analysis was to assess clinical and interventional data in patients treated with mechanical thrombectomy in case of ischemic stroke with mild-to-moderate symptoms. MATERIALS AND METHODS: We performed a retrospective analysis of a prospectively collected stroke data base. Inclusion criteria were anterior circulation ischemic stroke treated with mechanical thrombectomy at our institution between September 2010 and October 2015 with an NIHSS score of ≤8. RESULTS: Of 484 patients, we identified 33 (6.8%) with the following characteristics: median NIHSS = 5 (interquartile range, 4-7), median onset-to-groin puncture time = 320 minutes (interquartile range, 237-528 minutes). Recanalization (TICI = 2b-3) was achieved in 26 (78.7%) patients. Two cases of symptomatic intracranial hemorrhage were observed. Favorable (mRS 0-2) and moderate (mRS 0-3) clinical outcome at 90 days was achieved in 21 (63.6%) and 30 (90.9%) patients, respectively. CONCLUSIONS: The clinical outcome of patients undergoing mechanical thrombectomy for acute ischemic stroke with mild stroke due to large-vessel occlusion appears to be predominately favorable, even in a prolonged time window. However, although infrequent, angiographic complications could impair clinical outcome. Future randomized controlled trials should assess the benefit compared with the best medical treatment.

Mechanical Thrombectomy of Distal Occlusions in the Anterior Cerebral Artery: Recanalization Rates, Periprocedural Complications, and Clinical Outcome.

BACKGROUND AND PURPOSE: Patients with acute ischemic stroke in the anterior circulation are at risk for either primary or, following mechanical thrombectomy, secondary occlusion of the anterior cerebral artery. Because previous studies had only a limited informative value, we report our data concerning the frequency and location of distal anterior cerebral artery occlusions, recanalization rates, periprocedural complications, and clinical outcome. MATERIALS AND METHODS: We performed a retrospective analysis of prospectively collected data of patients with acute ischemic stroke undergoing mechanical thrombectomy in the anterior circulation between June 2010 and April 2015. RESULTS: Of 368 patients included in this analysis, we identified 30 (8.1%) with either primary (n = 17, 4.6%) or secondary (n = 13, 3.5%) embolic occlusion of the distal anterior cerebral artery. The recanalization rate after placement of a stent retriever was 88%. Periprocedural complications were rare and included vasospasms (n = 3, 10%) and dissection (n = 1, 3.3%). However, 16 (53.5%) patients sustained an (at least partial) infarction of the anterior cerebral artery territory. Ninety days after the ictus, clinical outcome according to the modified Rankin Scale score was the following: 0-2, n = 11 (36.6%); 3-4, n = 9 (30%); 5-6, n = 10 (33.3%). CONCLUSIONS: Occlusions of the distal anterior cerebral artery affect approximately 8% of patients with acute ischemic stroke in the anterior circulation receiving mechanical thrombectomy. Despite a high recanalization rate and a low complication rate, subsequent (partial) infarction in the anterior cerebral artery territory occurs in approximately half of patients. Fortunately, clinical outcome appears not to be predominately unfavorable.

Angiographic CT for intraprocedural monitoring of complex neuroendovascular procedures.

SUMMARY Evolving techniques in interventional neuroradiology have widened therapeutic options, allowing treatment even in complex cases. Complex neuroendovascular procedures (eg, stent-assisted coiling, stent placement in X- or Y-techniques) require precise delineation of cerebral vasculature and devices. However, because of the complex anatomy or if an ideal projection is not possible, visualization of the parent artery might be difficult. We present 2 complex cases of basilar tip aneurysm in which ACT proved to be beneficial in the intraprocedural monitoring of stent-assisted coil embolization.

Impaired osteoinduction in a rat model for chronic alcohol abuse.

Alcohol abuse is a risk factor for bone fractures. Following a fracture, alcoholics have a higher risk for impaired fracture healing. However, the specific alcohol-induced defect(s) in bone healing are not known. Alcohol is a potent inhibitor of bone formation during bone growth and turnover. Thus, the purpose of this study was to determine the effects of alcohol consumption on induction of new bone formation. Demineralized allogeneic bone matrix (DABM) cylinders were used to model osteoinduction in a rat model for chronic alcohol abuse. DABM cylinders, prepared from femurs and tibiae of rats fed a normal diet, were implanted into sexually mature male rats adapted to alcohol (ethanol contributed 35% of caloric intake) or control liquid diets. Food intake in the control rats was restricted to match food intake of alcohol-fed animals. The implants were recovered 6 weeks later and analyzed by histology, muCT and chemical analysis. Histological evaluation revealed a robust osteoinductive response, resulting in mature bone ossicle formation, in DABM implants in rats fed the control diet. Alcohol consumption affected bone mass and architecture of the DABM implants but not volumetric density or mineral composition. Specifically, alcohol consumption resulted in significant decreases in DABM-induced bone volume, bone volume/mg original cylinder weight, connectivity density, trabecular number and thickness, ash weight and % ash weight. There were no changes in mineral (ash) density nor in the relative amounts of calcium, magnesium, iron, selenium and zinc (microg/mg ash), indicating that alcohol consumption did not impair mineralization. Taken together, these results show that alcohol abuse resulted in decreased bone formation within the DABM implant. We conclude that reduced osteoinduction may contribute to impaired bone healing in alcoholics.

A brief screening tool for suicidal symptoms in adolescents and young adults in general health settings: reliability and validity data from the Australian National General Practice Youth Suicide Prevention Project.

Using data from a nationwide project on young people in Australia aimed at assessing suicidality in general health settings, we present a brief screening tool for suicidality (the depressive symptom index suicidality subscale). Two thousand eight hundred and fifty-one (15-24 year old) patients presenting to 247 Australian general practitioners between 1996 and 1998 were assessed. In addition to the suicide screen, patients completed the general health questionnaire-12 and the Center for Epidemiological Studies depression scale. Patients' chief complaints were taken from the summary sheets completed by their general practitioners. Using inter-item correlational and factor-analytic techniques, as well as a general approach to construct validity, we show that the measure has favorable reliability and validity characteristics. We also provide results on cut-points that may facilitate its use in clinical and research settings. Because the screen is brief, easy to use, reliable, and valid, we encourage its use to combat the vexing international health problem of suicide.

U.S. Army MEDEVAC in the new millennium: a medical perspective.

The U.S. Army Aeromedical Evacuation community (MEDEVAC) possesses a long-standing tradition of excellence in the care and transportation of combat casualties. Recent developments in civilian air medical transport and quantitative review of MEDEVAC operations have identified potential areas for improvement, concentrating on enhanced flight medic standards, training, sustainment and medical oversight of the air ambulance system. These proposed changes are discussed in detail, from the perspective of current emergency medicine and aviation medicine standards of practice. If instituted, these changes would facilitate the emergence of a true air medical transport capability comparable with the civilian community standard.