bluuebunny/crossref_metadata_2025 huggingface dataset:
Geometry Quantification of Abdominal Aortic Aneurysms
Authors: Shum Judy , Di Martino Elena , Muluk Satish , Finol Ender A.
Published: July 2013

Recent studies have shown that the maximum transverse diameter of an abdominal aortic aneurysm (AAA) and expansion rate are not entirely reliable indicators of rupture potential. We hypothesize that aneurysm morphology and wall thickness can be quantified in a systematic approach leading to accurate differentiation of the geometric characteristics of aneurysm population subsets. A non-invasive, image-based evaluation of AAA shape was implemented on a retrospective study of sixty-six subjects who underwent elective repair and twenty-eight subjects who suffered AAA rupture within 1 month of their last pre-operative follow-up. The contrast-enhanced computed tomography (CT) scans of these patients were used to generate three-dimensional models from the segmented images. Twenty-eight geometry-based indices were calculated to characterize the size and shape of the AAA sac, and regional variations in wall thickness were estimated based on a novel segmentation algorithm. A multivariate analysis of variance using a maximum AAA diameter of 5.5 cm as a factor was performed for all indices as dependent variables, for the electively repaired group. Box and Whisker plots and ROC curves were generated to determine the indices’ potential as predictors of rupture risk. Listed from highest to lowest area under the ROC curve (AUC), the following six indices were found statistically significant (p < 0.05): volume (V, p < 0.0001), surface area (S, p < 0.0001), intraluminal thrombus volume (VILT, p < 0.0001), diameter-to-diameter ratio (DDr, p < 0.0001), diameter-to-height ratio (DHr, p = 0.015), and centroid distance of the maximum diameter (dc, p = 0.008). Given that individual AAAs have complex, tortuous and asymmetric shapes with local changes in surface curvature and wall thickness, the assessment of AAA rupture risk should require the accurate characterization of aneurysmal sac shape.
Continuous Separation of Particles Using Contactless Dielectrophoresis
Authors: Sano Michael B. , Davalos Rafael V.
Published: July 2013

One of the most crucial processes in many biomedical applications is the separation of cells and micro-particles from biological fluids3. Water quality analysis to detect viable pathogenic bacterium2, and rare circulating tumour cells (CTCs) isolation from biological samples to detect cancer at its early stage1 are some of the important examples. Dielectrophoresis (DEP), is a technique for sample handling, which employs the electrical signatures of particles in the presence of non uniform electric fields to separate specific cell types4, 5.
Estimation of Pose and Medial/Lateral Contact Force Using Multi-Axial Load Measurements From an Instrumented Knee Implant
Authors: Meyer Andrew J. , D’Lima Darryl D. , Banks Scott A. , Coburn James , Harman Melinda , Fregly Benjamin J.
Published: July 2013

Accurate prediction of contact forces in the knee could be useful for the study of neuromusculoar coordination, the development of treatments for knee osteoarthritis, and the design of knee replacements with improved functionality or durabilty. To assist in these endeavors, researchers have recently designed and constructed novel knee implants capable of measuring four [1] or six [2] loads in vivo. These measurements provide valuable data for evaluating in vivo knee load predictions generated via computational models. One of the challenges of using these experimental data is converting the measured loads into medial and lateral contact forces — quantities that have clinical significance. Furthermore, it would be valuable if in vivo load measurements could be converted into accurate tibiofemoral pose estimates so that knee kinematics could be inferred from these unique load measurements as well.
The Effect of the Fascia on the Stress Distribution in Skeletal Muscle
Authors: Ramirez Angelica Maria , Calvo Calzada Begoña , Grasa Jorge
Published: July 2013

The human and vertebrate interaction with the environment is done primarily through the movement. This is possible due the skeletal muscle: anatomical structure able to contract voluntarily. The skeletal muscles are made up of contractile proteins which slide one over another allowing the muscle shortening and the body force generation. This protein structure of actin and myosin maintains its organization through the connective tissue that surrounds it (endomysium, perimysium and epimysium), creating arrays of myofibrils, fibre bundles, fascicles until conform the whole muscle. All this connective tissue extends to the ends of the muscle to form the tendon.
Measurement of 3D Vertebral Body Position and Orientation Using Single Plane Fluoroscopy
Authors: Conrad Bryan P. , Banks Scott A.
Published: July 2013

The increasing use of motion preserving devices in the spine has highlighted the need for accurate kinematic measurement tools to evaluate the performance of these new implants. In addition to quantifying the motion of the implant itself, it is also desirable to measure how implants affect the motion at adjacent vertebral levels. Single plane fluoroscopy has been used for over 15 years to analyze the in vivo motions of total knee replacement implants, with reported accuracies of 0.5–1.0 deg for rotations and 0.5 mm for in plane translations1,2. It is our goal to apply this type of image registration technique to the spine, so that accurate 3D kinematics of vertebral motion can be measured in vivo. This involves a significant extension to previous work, instead of tracking silhouettes of implants, we proposed to use digitally reconstructed radiograph images generated from a CT as the basis for image registration. The purpose of this project was to develop a methodology that would enable the 3D position and orientation (pose) of a vertebral body to be accurately measured from a single plane fluoroscopic image.
CFD Simulation of Flow Mixing in the Vertobrobasilar System
Authors: Bockman Matthew D. , Kansagra Akash P. , Wong Eric C. , Marsden Alison L.
Published: July 2013

Patient specific modeling can provide detailed hemodynamic information that is not available through most standard imaging modalities. The vertebrobasilar system is comprised of the confluence of the two vertebral arteries into the basilar artery, followed by divergence into the posterior cerebral arteries. A pilot study, by Kansagra and Wong [2], utilized vessel-encoded arterial spin labeling, an experimental MRI technique to quantify vertebrobasilar perfusion. In this method, flow in different vessels can be tagged, and perfusion of tagged flow to different regions of the brain can be quantified. These results demonstrated that blood delivered to the right hemisphere came primarily from the right vertebral, and vice versa.
Molecular Mechanosensors and Focal Adhesion Mechanotransduction
Authors: Mofrad Mohammad R. K.
Published: July 2013

Cellular response to mechanical stimulation is mediated by both biochemical mechanisms via changes in gene expression and by biophysical mechanisms via mechanically induced changes in specific molecules’ structure and function. These mechanically responsive molecules can be described as the cell’s mechanosensors and can function to initiate processes such as focal adhesion formation. A series of molecular dynamics investigations explore the mechanosensor function of key molecules involved in focal adhesion formation and cytoskeletal dynamics.
A Computational Framework for Optimization and Uncertainty Quantification in Surgical Design for Pediatric Cardiology
Authors: Marsden Alison L. , Yang Weiguang , Sankaran Sethuraman , Feinstein Jeffrey A.
Published: July 2013

Recent work has demonstrated substantial progress in capabilities for patient-specific cardiovascular flow simulations. In particular, pediatric cardiology is a field that stands to benefit particularly from patient specific simulations and design capabilities due to the large variation in anatomy among patients and challenging hemodynamics. Recent simulations in pediatric cardiology have emphasized the importance of exercise and respiration, and have been used to test newly proposed surgical designs.
Rapid, Low-Cost, Microfluidic Thermocycler for High-Throughput Genetic Diagnostics
Authors: Phaneuf Christopher R. , Pak Nikita , Forest Craig R.
Published: July 2013

Conventional instrumentation for amplifying nucleic acids by the polymerase chain reaction (PCR), which involves repeated temperature cycling, suffers from slow heating rates (e.g., 3 C/s) and large, costly sample volumes (i.e., 50 μL). Performing PCR is often the most time-consuming step in genetic sample preparation for common procedures such as pathogen detection and forensics. Faster thermocycling can reduce overall runtime and facilitate time-sensitive analyses. Smaller reaction volumes require fewer expensive reagents. Efforts to miniaturize genetic sample preparation have been largely confined to glass devices that are relatively expensive and require elaborate fabrication methods. Landers [1] has used glass microchips fabricated by wet etching to perform PCR, in which volumes of approximately 270 nL can be cycled 25 times with a tungsten filament lamp in only 5 min. Other developments include the work of Yasuda [2] and Faris [3], using infrared laser radiation to perform real-time PCR in 10–30 nL droplets suspended in mineral oil with amplification times of 3.5 and 6 min, respectively. Still, these devices can only perform a single reaction at a time.
Modeling the Interaction Between the Coronary Sinus and the Proximal Anchor Stent in Percutaneous Transvenous Mitral Annuloplasty
Authors: Sun Wei , DeHerrera Milton
Published: July 2013

Surgical treatment of severe functional mitral regurgitation (MR) often involves mitral annuloplasty, a procedure where a flexible or rigid annuloplasty ring is used to downsize the dilated mitral valve annulus (MA) and improve leaflet apposition by posterior annular correction. Recently various minimally invasive percutaneous transvenous mitral annuloplasty (PTMA) devices have been tested in patients who are not suitable candidates for a surgical procedure involving a thoracotomy. The approach is based on the concept that by utilizing the parallel location of the coronary sinus (CS) to the mitral annulus, a device, that can reshape the annulus, can be percutaneously deployed within the coronary sinus (CS) and the great cardiac vein (GCV). When the implanted device deforms, it shortens the MA anterior-posterior dimension and decreases mitral regurgitation (MR) (Fig. 1). Although the approach has been shown to be promising, PTMA device dysfunction and fatigue fracture have been reported in several firstin-human clinical trials (1). We hypothesize that quantitative understanding of the biomechanical interaction between the venous tissue, the mitral improve the efficacy of the PTMA treatment of MR. In this study, we aim to model interactions between the PTMA proximal anchor and the CS using computational tools.
Protective Capabilities of a Watersports Helmet for Boom-to-Head Impacts During Sailing
Authors: Stepan Lenka L. , Scher Irving S. , Thomas Reed
Published: July 2013

In sailing, the boom comes across the boat during tacks and jibes and has potential to impact a participant’s head and cause injury. To our knowledge, there are no sailing specific helmets on the market in the United States. To determine the effectiveness of a wakeboarding helmet to mitigate the risk of head injury, we measured the boom angular velocity on a 24-foot keel sailboat during controlled jibes. The boom motion was recreated in a laboratory setting and positioned to contact the occiput of the instrumented head of a Hybrid III 50th percentile male anthropometric testing device (ATD). Tests were conducted with an unhelmeted ATD and with an ATD wearing a wakeboarding helmet. Boom angular velocities and head accelerations for unhelmeted impacts were highly correlated (R2 = 0.996). The watersports helmet reduced head accelerations by 52 ± 4% when compared to accelerations from unhelmeted impacts.
Emergency department patient knowledge and physician communication regarding CT scans
Authors: Zwank Michael D , Leow Marissa , Anderson Christopher P
Published: July 2013

Objectives

This study evaluated several aspects of patients’ and providers’ knowledge and attitude regarding emergency CT scan use. Specifically, is patient awareness of radiation risks changing over time and do levels of education affect this knowledge? Meanwhile, do emergency medicine providers discuss risks with patients and do patients want to know about these risks?

Methods

We conducted a survey of clinically stable patients in the emergency department (ED) after undergoing a CT scan.

Results

200 patients were surveyed. 82 (41%) were aware that CT scans are associated with radiation exposure. 50 (25%) patients were aware that radiation from CT can increase overall lifetime risk of cancer compared with only 2/76 (3%) conducted in 2002. 29 (14.5%) providers specifically discussed radiation risk with patients prior to the CT. There was a significant trend towards knowledge that CT uses x-rays among those with more education. However, there was no association between level of education and knowledge of cancer risk associated with radiation risk from CT. 82 (41%) would have liked more information regarding radiation risks from the provider.

Conclusions

ED patient knowledge has increased significantly over the past 8 years. At the same time, there is a trend towards ED providers more commonly discussing these risks. Level of education is associated with knowledge that CT uses x-rays, but not with knowledge that this is associated with a greater risk of cancer. Patients often want to be informed of these risks.
Impact of introducing a major trauma network on a regional helicopter emergency medicine service in the UK
Authors: McQueen Carl , Crombie Nick , Perkins Gavin D , Wheaton Steve
Published: July 2013

Introduction

In the West Midlands region of the UK, the delivery of prehospital trauma care has recently been remodelled through the introduction of a regionalised major trauma network (MTN). Helicopter emergency medical services (HEMS) are integral to the network, providing means of delivering highly skilled specialist teams to scenes of trauma and rapid transfer of patients to major trauma centres. This study reviews the impact of introducing the West Midlands MTN on the operation of one its regional HEMS units.

Methods

Retrospective review of the Midlands Air Ambulance clinical database for the 6 months after the launch of the West Midlands MTN. The corresponding period for the previous year was reviewed for comparison. The contribution of trauma cases to overall workload, mission outcome data and the number of interventions performed at the scene were compared.

Results

The proportion of HEMS activations for trauma cases was similar in both cohorts (70.84% before MTN vs 71.57% after MTN). The proportion of mission cancellations was significantly lower after the launch of the network (23.71% vs 19.03%). Significantly more scene attendances resulted in interventions by HEMS crews after the MTN launch (44.66% vs 56.92%).

Conclusions

Since the introduction of the West Midlands MTN, tasking of HEMS assets appears to be better targeted to cases involving significant injury, and a reduction in mission cancellations has been observed. There is a need for more detailed evaluation of patient outcomes to identify strategies for optimising the utilisation of HEMS assets within the regional network.
E-045 A Randomised, Concurrent Controlled Trial to Assess the Safety and Effectiveness of the Penumbra Separator 3D as a Component of the Penumbra System in Acute Stroke Treatment
Authors: Frei D , Siddiqui A , Nogueira R , Mualem E , Sit S , Bose A
Published: July 2013

Introduction/Purpose

The goal of the Penumbra System®Separator 3D Trial (3D RCT) is to assess the safety and effectiveness of the 3D as a component of the Penumbra System®in the revascularisation of large vessel occlusion in acute ischaemic stroke. The novel Separator 3D, with intraluminal chambers to secure clot, should provide more effective clot removal with the large inner diameter aspiration catheters.

Materials and Methods

The 3D RCT is a prospective, multicentre, randomised, concurrent controlled, non-inferiority study. Up to 230 patients from 18 to 85 years old who present with large vessel occlusion (≥2.5mm) within 8 hours of symptom onset and are refractory to or not eligible for IV rtPA therapy are eligible. Patients with an NIHSS score of 8 or greater are randomised (1:1) to treatment with the Penumbra System including the 3D device or the Penumbra System alone. The primary endpoints are revascularisation of the target vessel as defined by a TICI score of 2 or 3 and incidence of 24-hour serious adverse events (SAEs). An independent, blinded Core Lab will review and assess imaging scans for TICI scores and ICH. A Clinical Event Committee/Data Safety Monitoring Board will evaluate SAEs and monitor safety. Secondary endpoints include good 90-day neurological and functional outcomes (NIHSS, mRS scores), all cause mortality, and incidence of symptomatic intracranial haemorrhage.

Results

To date, 25 centres are screening, and 80 patients are enrolled, of which 49 are randomised.

Conclusion

The Separator 3D Trial will determine if inclusion of a novel 3 dimensional clot retriever as a component of the Penumbra System®provides efficient revascularisation with acceptable safety.

Disclosures

D. Frei: 3; C; Penumbra, Inc. A. Siddiqui: None. R. Nogueira: None. E. Mualem: 5; C; Penumbra, Inc. S. Sit: 5; C; Penumbra, Inc. 6; C; Penumbra, Inc. A. Bose: 4; C; Penumbra, Inc. 5; C; Penumbra, Inc.
E-050 The Rationale for the Vertebral artery Ischaemia Stenting trial (VIST)
Authors: Clifton A , Markus H , Kuker W , Rothwell P
Published: July 2013

Symptomatic vertebral stenosis is associated with a high risk of recurrent stroke Most of this risk is in the first weeks Intracranial stenosis is associated with a higher risk Vertebral stenting looks promising but its use is unproven. Trials such as the Vertebral artery Ischaemia Stenting Trial are needed In any trial, or in clinical practice, patients needs to be randomised, and stented, urgently after first symptoms The higher stroke risk in intracranial stenosis means this group could benefit more, even if they have a higher intra-operative risk. The rationale for the VIST trial and an outline and recruitment update of the trial will be presented.

Disclosures

A. Clifton: None. H. Markus: None. W. Kuker: None. P. Rothwell: None.
E-053 Management of Tongue Venous and Lymphatic Vascular Malformations
Authors: Yakes W
Published: July 2013

Purpose

To determine the efficacy of ethanol embolisation in management of tongue vascular malformations.

Materials and Methods

Thirty-nine patients (22 females, 17 males; mean age: 38 years) presented with tongue vascular malformations. Forty-seven patients had undergone 61 failed previous procedures (embo, laser, surgery, steroid injection, alpha-interpheron, radiation). All patients had baseline arteriograms and MRs. All patients underwent direct puncture ethanol therapy.

Results

Of 39 patients with venous-lymphatic malformations, 27 patients had dramatic reduction and 12 patients’ therapy is on-going with concurrent reductions (mean f/up: 60 months). One patient with mixed veno-lymphatic malformation required surgical debulking of excess tissues (>90% after treatment). Minor complications such as tongue blisters (9 instances) healed spontaneously; 3 tongue mucosal injuries healed spontaneously; 3 infections responded to antibiotic treatment; 1 area of hemi-focal numbness resolved.

Conclusion

Ethanol embolotherapy is a primary form of therapy to eradicate low-flow vascular malformations of the tongue permanently at long-term follow-up. Rarely is concurrent surgery required except to debulk an enlarged tongue that shrink minimally after treatment of the underlying vascular malformation. Low complications are encountered. Partial or total glossectomy should be avoided.

Disclosures

W. Yakes: None.
E-056 MR CLEAN - Multicentre Randomised Clinical trial of endovascular treatment for acute ischaemic stroke in the Netherlands (NTR1804)
Authors: Majoie C , Berkhemer O , Beumer D , Oostenbrugge R van , Fransen P , Zwam W van , Lugt A van der , Roos Y , Dippel D
Published: July 2013

Rationale

Ischaemic stroke is often caused by embolic occlusion of proximal intracranial arteries. The effect of intravenous alteplase is limited in these patients. Endovascular treatment increases the likelihood of recanalisation, but the effect of treatment on functional outcome is not certain.

Aim

The main purpose of the Multicentre Randomised Clinical trial of Endovascular treatment for acute ischaemic stroke in the Netherlands (MR CLEAN) is to assess the effect on functional outcome and safety of endovascular treatment in patients with a proximal intracranial arterial occlusion in the anterior circulation.

Design

MR CLEAN is a pragmatic phase III multicentre randomised clinical trial with blinded outcome assessment. The intervention contrast is endovascular treatment with trombolytics (urokinase or alteplase) and/or mechanical trombectomy versus no endovascular treatment. The choice of endovascular treatment modality for each patient is left to the discretion of the local investigator and treating physicians. Background medical management is delivered according to national standards and guidelines. It may include intravenous alteplase within the first 4.5 hours after onset.

Outcomes

The primary outcome is the score on the modified Rankin scale (mRS) 90 days after inclusion in the study. Secondary outcomes are the NIHSS score at 24 hours, vessel patency, infarct size, and the occurrence of major bleeding. The randomisation will be stratified for use of intravenous alteplase, planned treatment modality (intra-arterial thrombolysis, mechanical trombectomy or both) treatment centre and stroke severity. The effect of treatment will be estimated by means of the ordinal logistic regression (shift analysis). In total, 500 patients will be included in the trial.

Discussion

The trial is going well. We estimated that inclusion of patients will take 4 years. The trial has started in December 2010. As of November 2012, 12 participating centres are active and 234 patients have been included.

Disclosures

C. Majoie: 1; C; Dutch Heart Foundation. 6; C; EV3, Penumbra, Angiocare, Top Medical, Lamepro/Medac. O. Berkhemer: None. D. Beumer: None. R. van Oostenbrugge: None. P. Fransen: None. W. van Zwam: None. A. van der Lugt: None. Y. Roos: None. D. Dippel: 1; C; Dutch Heart Foundation. 6; C; EV3, Penumbra, Angiocare, Top Medical, Lamepro/Medac.
E-062 Coiling Cost per Volume Analysis and Strategy for Cost Reduction
Authors: Wang C , Hui F
Published: July 2013

Introduction/Purpose

Aneurysm treatment is a major revenue driver of neurointerventional surgery. The cost of devices used during treatment has a direct effect on the profitability and financial sustainability of a given therapy. For aneurysm coiling procedures, the major component of material costs is the cost of implanted coils. As the healthcare system becomes increasingly cost-sensitive, understanding and controlling costs will prove to be instrumental in maintaining the future health of the specialty while maintaining patient outcomes.

Stable coil embolisation and aneurysm occlusion is not well understood, but may relate to packing density - achieving a minimum sum total coil volume. Other approaches include achieving lower porosity ratios at inflow zone of the aneurysm, which may achieve functional occlusion of an aneurysm despite residual internal unfilled volume. This approach is best exemplified by flow diversion devices.

Modelling the second approach is currently not feasible, as critical factors remain poorly understood, but modelling a reasonable strategy for minimising procedure material costs to achieve a minimum packing density may help identify methods of reducing coiling costs on a volumetric efficiency basis. To date no analysis has been done to model this relationship.

Materials and Methods

The price information for 468 different coils used by our institution were obtained by Q-Sight and normalised to the price of the least expensive coil. Coil volumes were lifted from the database of AngioSuite Neuro Edition software. Coils were grouped as frame, finish or fill coils by FKH by tertiary structural elements for framing coils, and size and length for finishing coils.

Results

Mean normalised coil cost per volume by categories yield 0.22 ± 0.24/mm3 for framing coils, 0.25 ± 0.22/mm3 for fill coils, and 0.99 ± 0.81 for finish coils. Between categories, there was no significant difference (p=0.32) between frame vs fill coils, but an extremely significant difference between both of the former vs finish coils (p < 0.000001). Individual cost/volume of each coil are collectively displayed in figure 1, grouped by coil type.

Conclusions

As a class, finishing coils are approximately 4 times as expensive as their frame and filling counterparts. Upon closer of figure 1 though, as a general trend smaller coils, regardless of frame, fill or finish designation, have a much higher cost per volume.

This analysis suggests that the approach when coiling to minimise costs is to always insert the largest volume coil possible.

Disclosures

C. Wang: None. F. Hui: None.
E-066 Follow Up and Complication Review of Symptomatic Intracranial Angioplasty and Stenting in a Non-Academic Setting
Authors: Parker M , Yin J , Rutledge N , Conrad K , Horowitz B , Luci J
Published: July 2013

Introduction/Purpose

Intracranial stenosis and treatment remains controversial based on mixed reports of complication rates and varying results of medical treatment. We reviewed our series of intracranial angioplasty and stenting done only on symptomatic patients refractory to medical management to the SAMMPRIS trial and as a basis for quality improvement.

Materials and Methods

A retrospective review of 42 sequential patients ranging from 29 to 86 years old (average 61) with symptomatic intracranial stenosis refractory to medical therapy and treated by angioplasty and stenting from December 2006 to March 2011 at our institution was undertaken. Four cases were not included in the analysis because of technical failure of stent placement.

Results

Average presenting stenosis was 74.5% and residual 15.8% after angioplasty and stenting. The patients were followed for up to 3 years.

Of the patients who received angioplasty and stenting 8.8% (4 patients) died within 30 days, three from complications of the procedure (6.8%) and one six days later from supraventricular tachycardia and cardiac arrest associated with a pre-procedure myocardial infarction.

Three additional patients had strokes associated with their procedures for a total complication rate of (13.3%) and five cases have shown asymptomatic restenosis (11%) in the past 3 years.

Compared to the SAMMPRIS trial the overall complication rate is similar (13.3%) versus (14%) with a higher death rate (6.8%) versus (2.2%)

Analysis of our deaths found that two of the deceased patients had hypertensive spikes during extubation and subsequently deteriorated after initially being neurologically intact. One of these patients developed a basal ganglia haemorrhagic transformation (HI2) and went on to have a large ischaemic MCA infarct, the other a subarachnoid haemorrhage consistent with vessel rupture.

Conclusion

We found that successful angioplasty and stenting can be performed in a nonacademic setting with similar complication rates to other reports. Choosing symptomatic patients that have failed aggressive medical management may account for our outcomes.

The two of the deaths in our series may be associated with complications from our anaesthesia care. We have since changed our protocol to have ongoing IV Bp and pain management during extubations.

Disclosures

M. Parker: None. J. Yin: None. N. Rutledge: None. K. Conrad: None. B. Horowitz: None. J. Luci: None.
E-071 Final Results of the Solitaire FR Thrombectomy for Acute Revascularisation (STAR) - Prospective, Multi-Centre, Controlled Clinical Trial in EU, Australia, and Canada
Authors: Bonafe A
Published: July 2013

Solitaire FR is the first in the new generation of mechanical thrombectomy devices based on a stent retriever technology for the treatment of acute ischaemic stroke. The Solitaire FR Thrombectomy for Acute Revascularisation (STAR) study is the largest controlled, prospective, multi-centre study on the use of a stentriever only (Solitaire FR) for acute ischaemic stroke.

Methods

Patients undergoing mechanical thrombectomy for acute ischaemic stroke in the anterior circulation were enrolled in 14 clinical sites in Europe, Canada and Australia. STAR is the first single arm, observational, controlled, multi-centre, prospective study using TICI 2b for revascularisation success. The aim of the study was to evaluate mechanical thrombectomy with the Solitaire FR when used as first intention device for the respective indications for mechanical thrombectomy. Patients were treated with the Solitaire FR Revascularisation Device in routine practice according to the ‘Instructions for Use’ (Balloon guiding catheter use and maximum number of 3 passes per vessel) to reach final result. The primary endpoint was revascularisation (TICI 2b) of the occluded vessel. The secondary endpoints were the clinical outcome mRS at 90 days, and time to revascularisation. The safety endpoints were the serious adverse events (SAEs) related to the device or the procedure. Patients were enrolled consecutively and there was an independent core-lab imaging review as well as a clinical events committee.

Results

202 patients were enrolled in the study with first enrolment in October 2010 and final enrolment in May 2012. The median age of the population was 72 years old and 60.4% of female patients. The median NIHSS was 17. Final patient follow-up occurred in September 2012 and the data has been completely independently monitored and core lab reviewed.

Conclusions

In patients with acute ischaemic stroke, treatment with the Solitaire FR device indicated a high level of success in revascularising vessels in the proximal circulation. In real-world practice using established protocols, the STAR results indicate a new paradigm for improving patient outcomes. (ClinicalTrials.gov numberNCT01327989).

Disclosures

A. Bonafe: 2; C; covidien.
E-072 Image Guided Targeted Radiofrequency (t-RFA) and Sacroplasty of Hypervascular Sacral Metastases for Pain Control
Authors: Zablow B
Published: July 2013

Haematogenous metastases to the sacrum can produce significant pain and lead to spinal instability. Conventional surgery to palliate pain with acceptable morbidity and mortality has been problematic given the usual short life expectancy of these patients and the high incidence of surgical complications. The Dfine STAR radiofrequency ablation system was recently approved for clinical use for the treatment of pain associated with bony spinal malignancy and other painful benign spinal lesions. In the subgroup of patients with hypervascular metastatic hepatocellular and renal cell cancer to the sacrum without neurological deficits, t-RFA and Sacroplasty using flat panel RCT or CT Fluroscopy in conjunction with electrophysiological monitoring preceeded by transarterial sacral embolisation has proven to be an effective method of pain palliation with extremely low morbidity in the eight patients performed to date. These patients have markedly reduced their requirements for narcotic analgesics and in most instances regained the ability to ambulate previously precluded by pain.

Disclosures

B. Zablow: None.
E-076 Fistulae at the Falx and Tentorium cerebelli; Liverpool series
Authors: Nahser H , Puthuran M , Chandran A , Javadpour M , Eldridge P
Published: July 2013

Dural arteriovenous fistulae at the falx and at the an terior and posterior margin of the tentorium cerebelli drain into cortical veins exclusively and their most common mode of presentation is haemorrhage. The concept of dural fistulae that involve smaller sinuses at the tent and falx was introduced by PICARD (1990, Journal of Neuroradiologie 17,161–181). We have retrospectively analysed a series of patients treated in between 2002 and 2012. 12 were found to be located at the falx and 30 located at the tent. One patient with an unruptured fistula died before treatment because of a haemorrhage. All other patients except one were treated initially with embolisation via feeding meningeal arteries with Onyx. This lead to radioanatomic cure in all but sixth patients. In the completely obliterated we observed that during this single feeder injection of Onyx 20 or 34 led to penetration to the origin of the first draining vein at the tentorial or falcine sinus and could then, with continued injection, retrogradely penetrate into the distal parts of the other feeding arteries leading to complete arterial disconnection from the venous side. In two patients for safety reasons to block retrograde embolisation of the internal carotid artery via the artery of Bernasconi, the internal carotid artery was temporarily blocked with a balloon at the origin of this branch during injection. One patient primarily and 3 others were then successfully occluded by surgery, the remaining by an endovascular transvenous approach with injection of Onyx. No lethal or complications with persistent disabling morbidity were recorded.

Disclosures

H. Nahser: 6; C; Support for Travel to meetings by various companies. M. Puthuran: 6; C; Support for Travel by various companies. A. Chandran: None. M. Javadpour: 6; C; Support for Travel to meetings by various companies. P. Eldridge: 6; C; support for Travel to meetings by various companies.
O-002 Initial Clinical Experience with the ADAPT technique: A Direct Aspiration first Pass Technique for Stroke Thrombectomy
Authors: Turk A , Spiotta A , Frei D , Mocco J , Baxter B , Siddiqui A , Mokin M , Dewan M , Turner R , Hawk H , Miranpuri B , Chaudry I
Published: July 2013

Background

The development of new revascularisation devices has improved recanalisation rates and time, but not clinical outcomes. We report our initial results with a new technique utilising a direct aspiration first pass technique with large bore aspiration catheter as the primary method for vessel recanalisation.

Methods

A retrospective chart review of 18 patients at 5 institutions was performed on patients where the ADAPT technique was utilised. The data represents the initial experience with this technique.

Results

The ADAPT technique alone was successful in 2/3 cases, although 4 cases had large downstream emboli that required additional aspiration. Four cases required the additional use of a stent retriever and one case required the addition of a Penumbra aspiration separator to achieve recanalisation. The average time from groin puncture to at least TICI 2b recanalisation was 30 minutes and all cases were successfully revascularised. TICI 3 recanalisation was achieved 72% of the time. On average, patients presented with an admitting NIHSS of 16.4 and improved to NIHSS of 3.1 by the time of discharge. There were no procedural complications.

Discussion

This initial experience highlights the importance of the technique with which new stroke thrombectomy devices are used may be as crucial as the device itself. The ADAPT technique is a simple cost effective method that is leading us to re-think our approach to acute ischaemic stroke thrombectomy by simply utilising the latest generation of large bore aspiration catheters independently to achieve excellent angiographic and clinical outcomes.

Disclosures

A. Turk: 1; C; Penumbra, Covidien, Microvention. A. Spiotta: None. D. Frei: None. J. Mocco: None. B. Baxter: None. A. Siddiqui: None. M. Mokin: None. M. Dewan: None. R. Turner: None. H. Hawk: None. B. Miranpuri: None. I. Chaudry: 1; C; Penumbra, Covidien, Microvention.
O-022 Perfusion-based selection leads to improved outcomes compared with time-based selection for endovascular reperfusion therapy in acute ischaemic stroke
Authors: Soltanolkotabi M , Prabhakaran S , Shaibani A , Hurley M , Curran Y , Conners J , Lee V , Ansari S
Published: July 2013

Background

Controversy exists on the role of perfusion imaging-based selection of patients with acute ischaemic stroke (AIS) for endovascular reperfusion therapy (ERT). Our hypothesis was that perfusion imaging based selection would improve functional outcomes at 3 months compared to time based selection alone.

Methods

We reviewed data from consecutive AIS patients treated with ERT at 4 centres between 2006 and 2011. We excluded patients with initial NIHSS score < 8 and those with posterior circulation occlusions. We collected data on demographics, initial NIHSS score, intravenous tissue plasminogen activator (IV tPA), use of perfusion imaging (CT or MRI), time from onset to groin puncture, initial and final reperfusion grade using the modified TICI scale, procedural complications using ECASS criteria, and functional outcome defined as modified Rankin Scale (mRS) 0–2 at 3 months. Using univariable statistics and multivariable logistic regression, we assessed whether patients who underwent perfusion imaging had better outcomes than those selected based on time alone. We estimated odds ratios (OR) and 95% confidence intervals (CI) in the final model.

Results

One-hundred eighty-five patients (mean age 66.7 years; median NIHSS score 19; MCA occlusion 73% and ICA occlusion 27%) were included. TICI 2b or 3 reperfusion grade was achieved in 49.7% while symptomatic haemorrhage (PH1, PH2, or perforation) occurred in 10.8%. Good outcome at 3 months was seen in 41.7%. Perfusion imaging was used in 69 (37.3%) patients (45 CT and 24 MRI) and was associated with increased onset-to-groin puncture time (359 vs 298 minutes, P=0.019). Patients who underwent perfusion imaging were also older (73 vs 63 years, P<0.001). Those who underwent perfusion imaging were more likely to have good outcome (53.6 vs 34.5%, P=0.011). In multivariable analysis, perfusion imaging remained a predictor of good outcome (adj. OR 2.35, 95% CI 1.17-4.72), independent of initial NIHSS score (adj. OR 0.91, 95% CI 0.86-0.97), TICI 2b or 3 reperfusion (adj. OR 4.94, 95 CI 2.50-9.76), and IV tPA use (adj. OR 2.50, 95% CI 1.26-4.94).

Conclusions

In this multi-centre study, AIS patients who underwent perfusion imaging were over 2-fold more likely to have good outcome following ERT despite a delay in time to treatment and age imbalance between groups. Further studies should continue to address the optimal perfusion imaging thresholds for patient selection for ERT.

Disclosures

M. Soltanolkotabi: None. S. Prabhakaran: None. A. Shaibani: None. M. Hurley: None. Y. Curran: None. J. Conners: None. V. Lee: None. S. Ansari: None.
O-026 Does Transfer Status Affect Outcomes in Acute Ischaemic Stroke Patients Treated Endovascularly?
Authors: Soltanolkotabi M , Shaibani A , Hurley M , Prabhakaran S , Lee V , Conners J , Ansari S
Published: July 2013

Background

Access to intra-arterial therapy (IAT) for acute ischaemic stroke (AIS) is limited to comprehensive stroke centres (CSCs) with timely access deemed critical for success. Inter-hospital transfers represent a growing subset of patients in which outcomes have not been well-studied.

Design/Methods

We retrospectively analysed consecutive anterior circulation AIS patients that underwent IAT at 4 institutions from2006–2011. We excluded patients selected using perfusion imaging. Patient demographics, medical risk factors, presentations, technical, and clinical (NIHSS and mRS scores) outcomes, complications, and mortality were studied. Symptom-onset, groin puncture, and end-of-procedure times were recorded. THRIVE scores were calculated. Successful recanalisation was defined as TIC I≥2b. Good functional outcome was defined as mRS 0–2 at 90 days. Patients were categorised into those who were transferred from outside institutions and those who presented directly to the CSCs.

Results

116 patients were studied. 68 (58.6%) were transferred from outside institutions. Transfers and non-transfers were similar in THRIVE scores (p=0.300), median symptom-onset to groin puncture times (306 vs 315 minutes; p=0.572), successful recanalisation (p=0.574), and symptomatic IC H (13.2 vs 10.4, p=0.776), but differed by age (59 vs 69 years; p=0.002), prior stroke (3% vs 22%, p=0.002), cardiac history (17.9 vs 36.6%, p=0.040), baseline NIHSS (20 vs 17, p=0.005), and location of occlusion (45.6% vs 22.9% IC A, p=0.012). Transfer patients had significantly worse outcomes at 90 days (mRS 0–2: 16.2% vs 60.4%, p>0.001). In multivariate analysis, transfer status was an independent predictor of poor functional outcome (adj. OR 0.05, 0.011 0.222), adjusting for relevant covariates.

Conclusions

Transferred AIS patients have worse functional outcomes at 90 days than non-transfers, independent of baseline risk factors, stroke severity, time to IAT, and procedural success/complications. Further investigation should focus on residual factors that may contribute to our findings such as baseline/final infarct volumes, pre-morbid functional status, and post-stroke care.

Disclosures

M. Soltanolkotabi: None. A. Shaibani: None. M. Hurley: None. S. Prabhakaran: None. V. Lee: None. J. Conners: None. S. Ansari: None.
P-003 Intracranial Aneurysms in the Youngest Patients: Characteristics and Treatment Challenges
Authors: Gross B , Smith E , Scott R , Orbach D
Published: July 2013

Background

Paediatric intracranial aneurysms have been reviewed in several recent series. These series have included patients up to ages 15–18. However, the characteristics and treatment challenges of aneurysms in young children differ from those in teenagers. As such, we focused on the cohort of children age 10 and under who presented with intracranial aneurysms, and discuss subtypes, presentation, treatment strategies, and outcomes.

Methods

With approval from the Boston Children’s Hospital Institutional Review Board, the records of children undergoing cerebral or spinal angiography by the senior author (DBO) from October 2006–June 2012 were reviewed to identify patients aged 10 and under who presented with intracranial aneurysm. Presentation, subtype of aneurysm, treatment strategy, and outcome were evaluated.

Results

Of 592 paediatric cases reviewed, 27 were for paediatric patients up to age 17 harbouring cerebral aneurysms (4.6%), and 15 occurred in children 10 years of age and younger (2.5%), with a mean age at presentation of 5.1 years (range, 3 months - 10 years). Of these fifteen children, 4 had characteristics of arterial dissection, 3 had angiographic characteristics of pseudoaneurysm (with all three having a history of prior microsurgery for tumour), 4 were fusiform, 3 were saccular (with 1/3 in a patient with PHACES and Moyamoya), and 1 was mycotic. Six patients underwent endovascular treatment, 1 underwent combined microsurgical and endovascular repair and 4 underwent microsurgical repair. Four patients have not been treated and are under current observation. One patient expired due to complications related to prior attempted aneurysm treatment at an outside facility, 1 patient expired from complications related to his malignant brain tumour, and 1 patient experienced complications related to attempted microsurgical repair; the other 11 patients are intact or have neurological compromise related to their initial presentation.

Conclusions

Previous investigations, including patients from birth to late teenage years, have documented unique characteristics of paediatric aneurysms relative to adults. We demonstrate that the youngest patients, those age 10 years and under, have aneurysms even more distinct than those in the larger paediatric cohort. These patients present unique treatment challenges.

Disclosures

B. Gross: None. E. Smith: None. R. Scott: None. D. Orbach: None.
P-014 Initial Experience with RF Ablation and Vertebral Augmentation in Spinal Neoplasms
Authors: Rutledge J , Conrad K , Parker M
Published: July 2013

Introduction

Over 1.5M patients are diagnosed annually with cancer in the United States. (Noone) The spine is the most common site of bone metastasis. Over 60% of spinal metastases are symptomatic (Maccauro) and often limit a patient’s ability to cooperate for radiation or chemotherapy. Although radiofrequency (RF) ablation has proven effective in providing palliative relief, the unique anatomy of the spine has resulted in limited adoption of RF ablation of such lesions.

Methods

A retrospective analysis was performed of 39 procedures in 27 patients with a wide variety of spinal neoplasms and secondary painful compression fractures which limited their ability to undergo conventional chemotherapy and radiation. Targeted RF ablation (t-RFA) followed by cement augmentation was performed via a minimally invasive coaxial system. An innovative RF ablation system (STAR) consisting of a robust articulating, navigational bipolar electrode containing two active thermocouples (TCs) permitted real time monitoring to determine the size of the ablations. Access and number of ablations were based on lesion size and location, and ability to articulate the bipolar electrode. Cement augmentation via the same guiding cannula was performed once physiologic temperature was confirmed.

Results

39 levels from T4 to S3 were treated successfully with RF ablation and vertebral augmentation without complication. Articulation of the ablation device enabled access to lesions throughout the vertebral bodies. Ablation zones were successfully controlled by monitoring TC temperature in-situ and, when necessary, adjusting power. No thermal injury occurred. Cement augmentation following t-RFA was efficient and resulted in a predictable filling. Pain control was rapidly achieved in all patients allowing them to restart chemotherapy or radiation therapy. One patient required addition RF ablation and vertebral augmentation at adjacent levels as his disease progressed and pain recurred.

Conclusion

Our initial clinical experience shows that targeted RF ablation using a novel articulating ablation technology, combined with vertebral augmentation, provides a safe method of stabilisation and pain control allowing patients who otherwise would be unable, to continue with conventional cancer therapy.

Disclosures

J. Rutledge: None. K. Conrad: None. M. Parker: None.