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Charles M Strother

Publications and source records attributed to Charles M Strother.

18 recordsLinked to original sources
PubMed2006

MR-visible coatings for endovascular device visualization.

PURPOSE: To investigate the potential utility of magnetic resonance (MR)-visible coatings for passive visualization of therapeutic endovascular devices such as catheters and guidewires. MATERIALS AND METHODS: Using a multistep coating process, gadolinium-based coatings were applied to commercially available off-the-shelf catheters and guidewires. These coated devices were imaged in phantoms made of fat-free yogurt, saline, and whole blood and also in live canine aorta on a 1.5-T cardiovascular MR scanner using T1-weighted two-dimensional radiofrequency (RF)-spoiled gradient-recalled echo, two-dimensional spin echo, and three-dimensional RF-spoiled gradient-recalled echo techniques. RESULTS: Commercially available off-the shelf catheters (4, 5, and 6 French) and guidewires (0.038 inch) were clearly visualized in all phantoms and canine aorta and the coatings proved to be durable and imageable without degradation in signal intensity up to 24 hours. MR-visible coatings address some of the shortcomings that have previously limited the role of MR as a guidance tool. CONCLUSION: Both in vitro and in vivo visualization of therapeutic endovascular devices coated with MR-visible coatings are found to be clinically viable.

4-Aminopyridine↗
PubMed2006

"Cross-over" technique for horizontal stenting of an internal carotid bifurcation aneurysm using a new self-expandable stent: technical case report.

OBJECTIVE AND IMPORTANCE: To describe the use of a newly available self-expandable stent in a cross-over approach for treatment of a large, wide-necked carotid termination aneurysm. CLINICAL PRESENTATION: A 58-year-old hypertensive woman presenting with mild headaches underwent computed tomography, which showed a nonruptured aneurysm of the left internal carotid artery. She subsequently underwent cerebral angiography, confirming that the aneurysm was located at the left terminal carotid segment with a wide neck. INTERVENTION: Using a cross-over approach from the contralateral internal carotid artery, a new self-expandable stent was advanced through the anterior communicating artery and placed horizontally across the aneurysm neck. Aneurysm occlusion was performed by subsequent trans-stent catheterization of the aneurysm and coil packing. CONCLUSION: Successful stent placement allowed subtotal coil occlusion of the aneurysm with a good anatomic and clinical result. No complications were encountered. The new self-expandable stent is a highly flexible, low-profile device that can be safely navigated through tortuous intracranial vessels even in a crossover technique. Its radial force and closed cell design is suitable for stent-assisted coiling and may be superior to stents with an open cell design.

Angioplasty, Balloon↗
PubMed2006

Increased cell opening and prolapse of struts of a neuroform stent in curved vasculature: value of angiographic computed tomography: technical case report.

OBJECTIVE AND IMPORTANCE: To describe the use of a new imaging tool, angiographic computed tomography, for visualization of cell opening and strut prolapse of a Neuroform 2 stent (Boston Scientific/Target, Fremont, CA) placed in curved vasculature for treatment of a basilar tip aneurysm. CLINICAL PRESENTATION: A 46-year-old woman presented with an unruptured 8-mm basilar tip aneurysm with a wide patulous neck. INTERVENTION: A 4 x 20-mm Neuroform 2 stent was placed across the aneurysm neck. Angiographic computed tomographic scanning was performed using a flat detector biplane angiographic system with new commercially available software (Dyna-CT; Siemens Medical Solution, Forchheim, Germany) and the following parameters: 20-second acquisition, 0.4-degree increment, 512 matrix in projections, 220-degree total angle, 20 degree/s, and approximately 15 to 30 frames/s, for a total of 538 projections. Image postprocessing was performed to correct scattered radiation, beam hardening, and ring artifacts on a commercially available workstation (Leonardo, Siemens Medical Solutions, Erlangen, Germany). The aneurysm was coiled in a second session, using bare platinum coils without clinical sequelae. CONCLUSION: Increased opening of cells and prolapsing of struts of an open cell design stent can occur after placement in a curved vessel across an aneurysm orifice. Angiographic computed tomography is a new imaging tool that provides visualization of intracranial stents that is superior to digital subtraction angiogram or nonsubtracted images. It will enhance our understanding of stent behavior in clinical practice and improve the efficacy and safety of intracranial stent placement. Further in vitro and in vivo imaging studies of intracranial stents are necessary to assess the value of this promising new technique.

Angiography, Digital Subtraction↗
PubMed2005

Training, competency, and credentialing standards for diagnostic cervicocerebral angiography, carotid stenting, and cerebrovascular intervention: a joint statement from the American Academy of Neurology, the American Association of Neurological Surgeons, the American Society of Interventional and Therapeutic Neuroradiology, the American Society of Neuroradiology, the Congress of Neurological Surgeons, the AANS/CNS Cerebrovascular Section, and the Society of Interventional Radiology.

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Angioplasty↗
PubMed2005

Self-expandable stent-assisted coiling of wide-necked intracranial aneurysms: a single-center experience.

BACKGROUND AND PURPOSE: Endovascular treatment of wide-necked aneurysms remains a therapeutic challenge. We conducted this study to evaluate the angiographic results and clinical outcome of patients treated with stent-assisted coiling by using a recently available self-expandable intracranial stent. METHODS: A retrospective review of all patients treated with self-expandable stent-assisted coiling between September 2002 and December 2003 was done. Treatment was attempted in 32 patients with 35 aneurysms. Four of the aneurysms were ruptured. All had either a dome-to-neck ratio less than 2 and/or a neck diameter of 5 mm or larger. Following stent placement, coiling was attempted in 33 of 34 aneurysms. The technical success of the procedure, procedure related complications, and the angiographic results were documented. RESULTS: In 34 of 35 aneurysms, stent deployment across the neck of the aneurysm was successful. Coiling was performed successfully in 30 of 33 aneurysms. In 20 aneurysms, immediate posttreatment angiography showed either total (17%) or satisfactory (50%) occlusion. Procedure-related mortality occurred in one patient (3.1%). Adverse events occurred in eight patients (25%); in three of them permanent neurologic deficit resulted (9.3%). In six patients, thrombus formation occurred within the stented segments during the procedure and reopro infusion was used. Follow-up angiography was available in 12 (40%) of 30 treated aneurysms. CONCLUSION: In our practice use of the self-expandable stent seemed to facilitate endovascular treatment of wide-necked intracranial aneurysms. Difficulty of deployment and stent thrombogenicity are the main drawbacks of the system.

Adult↗
PubMed2005

Angiographic CT in cerebrovascular stenting.

We evaluated the feasibility of angiographic CT (ACT) for visualizing metallic stents in three patients who underwent intracranial (n = 2) or extracranial (n = 1) stent placement to treat atherosclerotic lesions. ACT is a new technique that provides cross-sectional CT-like images based on rotational radiography performed with a rotating C-arm-mounted flat-panel detector. ACT allowed for the clear visualization of stents in both intracranial and extracranial arteries and was superior to conventional digital subtraction angiography and digital radiography in visualizing both the stent struts and their relationships to the arterial walls and aneurysmal lumen.

Aged↗
PubMed2005

Stent-assisted coiling of intracranial aneurysms aided by virtual parent artery reconstruction.

The availability of stents designed specifically for use in the intracranial vasculature has increased the use of stent-assisted coiling for treatment of wide-necked and complex intracranial aneurysms. We present a technique for pretreatment planning and visualization of a virtual stent within the parent artery by using a virtual reconstruction of the parent artery across the aneurysm neck. As illustrated by 2 clinical examples, this method provides information not otherwise available regarding the location of portions of the stent that are not visible on fluoroscopy. During treatment, this information enhances the ability to determine the location of coils in relation to the stent boundaries and should thereby improve the ability to avoid parent artery compromise.

Angiography, Digital Subtraction↗
PubMed2004

A technique for improved quantitative characterization of intracranial aneurysms.

3D digital subtraction angiograms of two intracranial aneurysms were imported to a workstation for reconstruction and postprocessing into a format allowing delineation of 1) the extent to which the diameter of the parent artery is incorporated into the aneurysm ostium (percentage of parent artery involvement or neck angle) and 2) the aneurysm volume and surface area. For clear visualization, 3D surface-rendered objects of the reconstructed artery, neck angle, and aneurysm were created.

Angiography, Digital Subtraction↗
PubMed2002

Combined time-resolved and high-spatial-resolution 3D MRA using an extended adaptive acquisition.

PURPOSE: To combine the benefits of time-resolved dynamic imaging and single elliptical centric acquisitions in a reasonable scan time. MATERIALS AND METHODS: A time series of images with moderate spatial resolution was acquired using the 3D Time-Resolved Imaging of Contrast KineticS (3D TRICKS) technique with elliptical centric encoding during contrast arrival. Following venous opacification, a complete large centrically encoded k-space volume was acquired. The high-spatial-frequency portions of this volume were combined with a 3D TRICKS time frame to form a high-resolution image. An additional single image is formed by suppressing background and signal averaging all acquired data, including post-venous low-spatial-frequency data. For this image, 2D temporal correlation analysis is used to suppress low-spatial-frequency vein contributions. Arrival time and spatial correlations are used to suppress background. RESULTS: The 3D TRICKS time frame may be selected to ensure a combined high-resolution image that has optimal central k-space sampling for any vascular region. The single image formed by signal averaging all acquired data has increased contrast-to-noise (CNR) and signal-to-noise (SNR) ratios. CONCLUSION: The advantages of time-resolved and high-spatial-resolution imaging were combined using an extended dual-phase acquisition. Some SNR and CNR gain was achieved by signal averaging. This process is facilitated by background and vein suppression.

Animals↗
PubMed2002

Effect of Guglielmi detachable coils on intraaneurysmal flow: experimental study in canines.

BACKGROUND AND PURPOSE: Guglielmi detachable coils (GDCs) are effective in preventing rebleeding of ruptured aneurysms. To better understand the mechanism underlying this protective effect, we evaluated blood flow in aneurysms and their parent arteries before and after GDC coil placement. METHODS: An 0.14-inch guidewire containing a combined pressure and thermistor sensor was inserted through a microcatheter into both the parent artery and the dome of surgically created canine aneurysms. Before and after GDC coil placement, intravascular pressures and thermodilution responses where recorded in the parent artery and aneurysmal dome during injections of room-temperature isotonic sodium chloride solution over 4 seconds (5 mL/s) and 2 seconds (20 mL/s) in the parent artery. RESULTS: Before GDC coil placement, similar U-shaped thermodilution curves were present in the parent artery and in the dome of the aneurysm. GDC coil placement reduced intraaneurysmal flow by 61-99.6% (P <.05), prolonged aneurysmal filling and washout (dilution interval increased from 5.16 seconds before coil placement to 26.79 seconds after coil placement, P < 0.05), and caused a dissociation of pressure and flow (shift epsilon was 0.45 seconds before coil placement versus 0.56 seconds after coil placement, P <.05). Flow in the parent artery was not significantly affected by GDC coil placement in the aneurysm. CONCLUSION: In this model, intraaneurysmal blood flow can be evaluated with thermodilution. GDC coil placement significantly reduces blood flow in aneurysms.

Animals↗
PubMedDate not supplied

Mycotic carotid artery pseudoaneurysm following stenting--a case report and lessons learned.

Carotid stenting is assuming an important role in the management of carotid disease. Surgeons although hesitant to embrace catheter treatment for the management of primary carotid artery disease, are more enthusiastic regarding it's use in the treatment of recurrent stenoses. This report suggests that caution should be exercised in the selection of patients to be treated with carotid stenting for recurrent disease.

Aneurysm, False↗
PubMedDate not supplied

Hemodynamic versus hydrodynamic effects of Guglielmi detachable coils on intra-aneurysmal pressure and flow at varying pulse rate and systemic pressure.

BACKGROUND AND PURPOSE: Alterations in intra-aneurysmal pressure and flow have been observed after treatment with Guglielmi detachable coils (GDCs). We wished to determine whether these changes could be assigned to a hydrodynamic effect of the coils themselves or a compound effect of coils plus thrombus formation. METHODS: Intra-aneurysmal pressure and flow were measured with a 0.014-inch guidewire- mounted transducer in a canine aneurysm in vivo and in vitro before and after treatment with GDCs. Flow was evaluated by using the thermodilution technique. Pressure and flow were also recorded in a bifurcational silicone aneurysm mounted onto a flow phantom during variations in systemic pressure and pulse rate before and following the insertion of GDCs. RESULTS: The insertion of GDCs induced a reduction in flow that was qualitatively similar when the aneurysm was perfused either by blood (in vivo) or with normal saline (in vitro). Quantitatively, however, flow was reduced less distinctly during perfusion with saline. In the silicone aneurysm, pressure was inversely related to pulse rate and increased with augmenting systemic pressure, whereas flow remained constant regardless of variations in pressure and pulse rate. After GDC placement, reduced flow was dependent on pulse rate but independent of systemic pressure. CONCLUSION: GDCs significantly reduced flow even in the absence of thrombus, indicating that they have a purely hydrodynamic effect. In the silicone model, the decrease in intra-aneurysmal flow after coiling relied upon the pulse rate in a manner suggesting the presence of resonance phenomena.

Aneurysm↗
PubMedDate not supplied

Endovascular treatment of high-flow carotid cavernous fistulas by stent-assisted coil placement.

BACKGROUND AND PURPOSE: Endovascular techniques are the methods of choice for the treatment of patients with carotid cavernous fistulas. We report our experience using stent-assisted coil placement for treatment of patients with high-flow fistulas that are associated with severe laceration of the internal carotid artery. METHODS: In a retrospective review of an internal endovascular therapy database covering the interval between October 2001 and October 2003, we identified a total of 5 patients presenting with 6 high-flow type A carotid cavernous fistulas (one had a bilateral fistula) that were associated with severe laceration of the internal carotid artery. All were treated first with stenting of the injured segment of the internal carotid artery followed by transarterial (3/6) and/or transvenous (4/6) obliteration of the fistula with detachable platinum coils. In 2 cases, a liquid adhesive was also used. In all instances, a compliant balloon was inflated within the stented arterial segment during coil deposition to avoid extension of coils into the parent artery. RESULTS: All 6 fistulas were obliterated, and each internal carotid artery was successfully reconstructed. Except for posttraumatic cranial nerve dysfunction in 1 patient, clinical outcome was very good. Follow-up angiograms in 3 of the 6 patients obtained at intervals between 3 and 6 months (mean, 4.5 months) revealed no fistula recurrence and no evidence of intimal hyperplasia within the stent. CONCLUSION: In this series of patients with high-flow carotid cavernous fistula associated with severe injury to the internal carotid artery, stent-assisted coil placement offered a safe and effective treatment. Stent-assisted coil placement may increase the ability to successfully treat fistulas with severe injury to the internal carotid artery with preservation of the parent artery.

Adult↗