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Guide Wire (guide + wire)
Selected AbstractsMR imaging in assessing cardiovascular interventions and myocardial injuryCONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2007Alexis Jacquier Abstract Performing an MR-guided endovascular intervention requires (1) real-time tracking and guidance of catheters/guide wires to the target, (2) high-resolution images of the target and its surroundings in order to define the extent of the target, (3) performing a therapeutic procedure (delivery of stent or injection of gene or cells) and (4) evaluating the outcome of the therapeutic procedure. The combination of X-ray and MR imaging (XMR) in a single suite was designed for new interventional procedures. MR contrast media can be used to delineate myocardial infarcts and microvascular obstruction, thereby defining the target for local delivery of therapeutic agents under MR-guidance. Iron particles, or gadolinium- or dysprosium-chelates are mixed with the soluble injectates or stem cells in order to track intramyocardial delivery and distribution. Preliminary results show that genes encoded for vascular endothelial and fibroblast growth factor and cells are effective in promoting angiogenesis, arteriogenesis, perfusion and LV function. Angiogenic growth factors, genes and cells administered under MR-guided minimally invasive catheter-based procedures will open up new avenues in treating end-stage ischemic heart disease. The optimum dose of the therapeutic agents, delivery devices and real-time imaging techniques to guide the delivery are currently the subject of ongoing research. The aim of this review is to (1) provide an updated review of experiences using MR imaging to guide transcatheter therapy, (2) address the potential of cardiovascular magnetic resonance (MR) imaging and MR contrast media in assessing myocardial injury at a molecular level and labeling cells and (3) illustrate the applicability of the non-invasive MR imaging in the field of angiogenic therapies through recent clinical and experimental publications. Copyright © 2007 John Wiley & Sons, Ltd. [source] Newly Developed Ultrasonic Probe With Ropeway System for Transpapillary Intraductal Ultrasonography of the Bilio,Pancreatic Ductal SystemDIGESTIVE ENDOSCOPY, Issue 3 2000Naotaka Fujita Background: Intraductal ultrasonography of the bile/pancreatic duct using a thin-caliber ultrasonic probe (IDUS) provides excellent images of these ducts and the surrounding structures. Insertion of the device through the papilla of Vater is essential to carry out this examination. We developed a new probe with a ropeway system (XUM5RG-29R; Olympus, Tokyo) for transpapillary IDUS. Its usefulness such as ease of application and safety were prospectively evaluated. Patients and methods: During the period of October 1997 to April 1998, transpapillary IDUS using the probe was performed in 194 patients at seven medical institutions. The success rates of insertion of the probe into the bile/pancreatic duct, observation of the area of interest, and the incidence of complications were evaluated. Results: Passage of the probe through the papilla was successful without difficulty in all the patients. Successful introduction of the probe into the pancreatic duct, bile duct and both of the ducts was achieved in 98.4, 100 and 85% of the patients, respectively. Once the probe was introduced into the aimed duct, it was possible to obtain IDUS images of the area of interest in all but five patients. Mild acute pancreatitis developed in eight patients (4.1%), all of whom recovered with conservative therapy only. Conclusions: It is possible to introduce the new ultrasonic probe into the desired duct once a guide wire has been inserted. This type of ultrasonic probe is quite useful when performing transpapillary IDUS of the bile and/or pancreatic duct. [source] Navigation by Parallax in Three-Dimensional Space During Fluoroscopy: Application in Guide Wire-Directed Axillary/Subclavian Vein PuncturePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2007ERNEST W. LAU M.D. Background:Fluoroscopy is range ambiguous,the relative positions in three-dimensional space of two structures with superimposed silhouettes cannot be ascertained. The parallax effect can be used to overcome this problem, and was used to develop a technique of axillary/subclavian vein puncture. Method:Patients requiring axillary/subclavian vein puncture were considered for the new technique. The vein was marked by a guide wire placed inside. In the postero-anterior (P-A) caudal projection, the needle was advanced dorsally from medial to the coracoid process at an arbitrary angle until its tip overlay the guide wire over the first intercostal space. Depending on whether the needle tip appeared caudad or cephalad of the guide wire in the P-A projection, the needle was advanced farther into or withdrawn back from the body, with its tip maintained over the guide wire in the P-A caudal projection at all times. Maneuvering of the needle stopped when the needle tip overlay the guide wire in both the P-A caudal and P-A projections or blood was aspirated. Result:Forty-one separate successful punctures were performed in 20 patients. No complications were recorded. Each puncture took no more than 1 minute, and the image intensifier needed to swing between the P-A caudal and the P-A projections only twice. Conclusions:The new technique was effective, efficient, and safe when implemented in clinical practice, justifying the parallax principles on which it is based. The parallax principles may be applied to other invasive medical procedures with due modifications. [source] Nitinol mandril guide wire facilitates percutaneous subclavian vein cannulation in a very small preterm infantPEDIATRIC ANESTHESIA, Issue 3 2006Christian Breschan MD DEAA No abstract is available for this article. [source] Impact of 16-slice computed tomography in percutaneous coronary intervention of chronic total occlusionsCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2006Naoyuki Yokoyama MD Abstract The main reason for failure of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is because the calcified plaque prevents the guide wire crossing the occlusion. We aimed to identify the route, and characterize plaque components within CTO, using 16-slice computed tomography (MSCT). Twenty three angiographic CTO in 22 patients (mean age 69 ±± 5 years, 17 males) were included. All patients had undergone MSCT prior to PCI. Images were analyzed for lesion visibility and plaque characteristics of CTO. The presence and location of calcified plaque within the CTO were systematically assessed. Each lesion was classified as a noncalcified, moderately calcified, or exclusively calcified plaque. Procedural failure was defined as the inability to cross a guide wire through the occlusion. All coronary routes of CTO segment were visualized. MSCT revealed three markedly bent CTO segments (13.0%), which could not be identified by coronary angiography only. Calcified plaques were detected in 30 lesions of 19 CTO segments (82.6%), but were not detected in the other four. The majority of calcified plaque was located in the proximal lesion, or both proximal and distal lesions. Fifteen out of 30 calcified lesions (50.0%) were exclusively calcified plaques. Overall procedural success was obtained in 21 CTOs (91.3%). MSCT can accurately identify the route of the CTO segment and evaluate both distribution and amount of the calcified plaque within it. Even with the complicated and/or calcified lesions, PCI success rate was excellent under MSCT guidance. MSCT should become a useful tool in PCI of CTO. © 2006 Wiley-Liss, Inc. [source] Acute decrease of coronary flow after indomethacin delivery in newborn lambsACTA PAEDIATRICA, Issue 10 2007Solweig Harling Abstract Aim: To document the effects of indomethacin (IND) on coronary flow. Methods: We studied nine premature lambs during the first day of life. The gestational age varied between 132 and 134 days (term 145 days) and weight 3.1,4.7 kg. Coronary flow velocities were recorded with an intracoronary Doppler guide wire in the proximal left anterior descending coronary artery (LAD). Average peak flow velocity was measured before, during and after an intravenous IND injection of 0.2 mg per kilogram of body weight. Results: IND increased systemic blood pressure (p < 0.05) and rate pressure product (RPP; p < 0.05) indicating that IND increased cardiac workload. IND decreased coronary average peak flow velocity in all lambs (p < 0.05). The maximal fall in coronary velocity appeared after 3 min (range 1,7 min) and was regained 10 min (range 4,53 min) after the drug delivery. The maximal reduction of coronary average peak flow velocity was 52% (median 26). The recovery time was directly related to the maximal reduction of the coronary average peak flow velocity (R = 0.91, R2 0.84, p < 0.002). Conclusion: Coronary flow velocity decreased markedly in premature born lambs given a bolus dose of IND. [source] Acetylcholine- and ergonovine-induced coronary microvascular spasm reflected by increased coronary vascular resistance and myocardial lactate productionCLINICAL CARDIOLOGY, Issue 3 2000Masashi Horimoto M.D. Abstract Diagnosis of coronary microvascular spasm remains largely speculative because it has been mostly based on chest pain and electrocardiographic ST-segment shift with slow filling of contrast medium into the coronary artery. A patient with resting chest pain and normal coronary angiograms underwent provocative tests with intracoronary acetylcholine (ACh) and ergonovine. During the tests, coronary diameter and flow velocity in the left anterior descending (LAD) coronary artery were measured with quantitative coronary angiography and intracoronary Doppler guide wire, respectively. Vascular resistance of the LAD and lactate production were determined separately. With injections of 100 ,g of ACh and 20 ,g of ergonovine, chest pain occurred with ST-segment elevation in the precordial leads in the absence of epicardial coronary spasm. Coronary vascular resistance increased by 2.2- and 1.6-fold of the baseline value with ACh and ergonovine, respectively. Myocardial lactate production was noted during the ST-segment elevation. Coronary microvascular spasm was verified by the increment in coronary vascular resistance and myocardial lactate production with concomitant ST-segment elevation in the presence of normal coronary angiograms. [source] Technique of endoscopic retrograde puncture and dilatation of total esophageal stenosis in patients with radiation-induced stricturesHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 2 2004Ronald J. Lew MD Abstract Background. Complete esophageal stenosis can occur after external beam radiation therapy for malignancies. Treatment for this complication has traditionally involved surgery. Methods. A new technique to reestablish luminal patency is described. This minimally invasive technique involves retrograde endoscopy by means of gastrostomy tube tract and puncture of the stenotic occlusion followed by stricture dilatation. The procedure is performed under combined endoscopic and laryngoscopic guidance. Results. Five consecutive patients who had complete esophageal stenoses develop after radiation therapy for malignant disease underwent retrograde endoscopy by way of gastrostomy tube tracts. Stenoses were punctured under endoscopic and laryngoscopic guidance with guide wires. Strictures were dilated with wire-guided balloons or polyvinyl dilators. Luminal patency was established in all patients using this technique without procedural complications. Conclusions. Endoscopic retrograde puncture and dilatation of total esophageal stenoses is safe, effective, and useful to reestablish luminal patency for radiation-induced strictures. This technique should be attempted before more invasive treatments. © 2004 Wiley Periodicals, Inc. Head Neck26: 179,183, 2004 [source] Heparin release from slippery-when-wet guide wires for intravascular useJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 6 2002Camiel C. L. Peerlings Abstract Thin metallic wires with an adherent hydrophilic/ lubricious polymeric coating were manufactured in a new extrusion-like procedure. This procedure is part of a novel and efficient way of assembling lubricious guide wires for intravascular interventions, such as percutaneous transluminal angioplasty. It is reported that heparin can readily be incorporated in the hydrophilic coating. A set of heparin-containing guidewire models was made and studied in detail. This showed that (i) immersion of the guide-wire models in an aqueous environment leads to release of heparin from their surface; (ii) the presence of heparin in the coating does not impede the lubricity of the coils; (iii) addition of stearic acid in the coating, next to heparin, does not influence the lubricity of the guide-wire models. Two different charges of heparin (designated heparin-low and heparin-high) were incorporated in the coating. It is discussed that release of heparin from the surface of medical devices (e.g. guide wires and catheters) is much more effective than systemic heparinization, basically because dissolved heparin molecules have a much larger probability of simply passing a medical device's surface (axial convection) rather than contacting it (radial diffusion). © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 692,698, 2002 [source] | ||||||||||