Fluoroscopy

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Fluoroscopy

  • x-ray fluoroscopy

  • Terms modified by Fluoroscopy

  • fluoroscopy exposure
  • fluoroscopy time

  • Selected Abstracts


    Reduced Fluoroscopy During Atrial Fibrillation Ablation: Benefits of Robotic Guided Navigation

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2010
    DANIEL STEVEN M.D.
    Reduced Fluoroscopy in PVI Using RN.,Background: Recently, a nonmagnetic robotic navigation system (RN, Hansen-SenseiÔ) has been introduced for remote catheter manipulation. Objective: To investigate the influence of RN combined with intuitive 3-dimensional mapping on the fluoroscopy exposure to operator and patient during pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) in a prospective randomized trial. Methods: Sixty patients were randomly assigned to undergo PVI either using a RN guided (group 1; n = 30, 20 male, 62 ± 7.7 years) or conventional ablation approach (group 2; n = 30, 14 male, 61 ± 7.6 years). A 3-dimensional mapping system (NavXÔ) was used in both groups. Results: Electrical disconnection of the ipsilateral pulmonary veins (PVs) was achieved in all patients. Use of RN significantly lowered the overall fluoroscopy time (9 ± 3.4 vs 22 ± 6.5 minutes; P < 0.001) and reduced the operator's fluoroscopy exposure (7 ± 2.1 vs 22 ± 6.5 minutes; P < 0.001). The difference in fluoroscopy duration between both groups was most pronounced during the ablation part of the procedure (3 ± 2.4 vs 17 ± 6.3 minutes; P < 0.001). The overall procedure duration tended to be prolonged using RN without reaching statistical significance (156 ± 44.4 vs 134 ± 12 minutes, P = 0.099). No difference regarding outcome was found during a midterm follow-up of 6 months (AF freedom group 1 = 73% vs 77% in group 2 [P = 0.345]). Conclusion: The use of RN for PVI seems to be effective and significantly reduces overall fluoroscopy time and operator's fluoroscopy exposure without affecting mid-term outcome after 6-month follow-up. (J Cardiovasc Electrophysiol, Vol. 21, pp. 6,12, January 2010) [source]


    Fluoroscopy and risk of cancer in children

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2009
    C. R. Thangaswamy
    No abstract is available for this article. [source]


    Jejunal access loop cholangiogram and intervention using image guided access

    JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 1 2010
    KS Amitha Vikrama
    Summary Jejunal access loop is fashioned in patients who undergo Roux en Y hepaticojejunostomy and biliary intervention is anticipated on follow up. Post-operative study of the biliary tree through the access loop is usually done under fluoroscopic guidance. We present a series of 20 access loop cholangiograms performed in our institution between August 2004 and November 2008. We aimed to evaluate the safety and efficacy of the procedure and to highlight the role of CT guidance in procuring access. Access loop was accessed using CT (n = 13), ultrasound (n = 3) or fluoroscopic guidance (n = 4). Fluoroscopy was used for performing cholangiograms and interventions. Twelve studies had balloon plasty of the stricture at anastomotic site or high up in the hepatic ducts. Seven studies showed normal cholangiogram. Plasty was unsuccessful in one study. Technical success in accessing the jejunal access loop was 100%; in cannulation of anastomotic site and balloon plasty it was 95%. One case required two attempts. Procedure-related complications were not seen. All patients who underwent balloon plasty of the stricture were doing well for variable lengths of time. Access loop cholangiogram and interventions are safe and effective. CT guidance in locating/procuring the access loop is a good technique. [source]


    Navigation by Parallax in Three-Dimensional Space During Fluoroscopy: Application in Guide Wire-Directed Axillary/Subclavian Vein Puncture

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2007
    ERNEST 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]


    Investigation of Cervical Patency and Uterine Appearance in Domestic Cats by Fluoroscopy and Scintigraphy

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 5 2002
    K Chatdarong
    Contents The cervical patency of six domestic female cats was monitored under sedation by infusion of contrast medium (Omnipaque) into the cranial vagina during early oestrus, mid-oestrus, late oestrus and interoestrus or a radiopharmaceutical (99mTc-HSA) during mid- and interoestrus in a non-ovulatory oestrous cycle. The transport of the contrast medium or the radiopharmaceutical through the cervix and within the uterine horns was observed under fluoroscopy and with the aid of scintigraphy. In three of the queens, transcervical transport of contrast medium was demonstrated in all stages of oestrus, in one queen during mid-oestrus, late oestrus and 1 day after oestrus, and in two queens only during late oestrus. The relations between the cervical patency to the contrast medium and the oestrous behaviour, cornification of the vaginal cells and the serum oestradiol-17, concentration were evaluated, and a relationship was found between the cervical patency and the degree of vaginal cornification. Transcervical transport of the radiopharmaceutical was observed in three queens during mid-oestrus. When the cervix was open, hysterography under a fluoroscope and hysteroscintigraphy were performed. The fluoroscopic and scintigraphic recordings revealed the patterns of the uterine contractions during oestrus in both ascending and descending directions, and the movement of the uterine contents back and forth between the uterine horns. The hysterograms were classified according to the shape of the uterine horns and the appearance of the endometrial lining. Spiral-shaped uterine horns with a smooth inner contour were observed in two queens, and a corkscrew appearance with irregular filling defects in the uterine lumen was shown in two queens that had developed subclinical cystic endometrial hyperplasia. These findings demonstrated that fluids or particles deposited in the cranial vagina of the cat can be transported into the uterus during some stages of the oestrous cycle. The fluoroscopic and scintigraphic techniques developed in this study may be further modified to permit more detailed studies of uterine contractile patterns and sperm transport in the feline female reproductive tract. Hysterography proved useful to diagnose uterine disease. The information on cervical patency is of value also for the development of techniques for artificial insemination in this species, and should be studied also in the ovulatory cycle. [source]


    Fluoroscopy guided vascular access: Asking the right question, but getting the wrong answer?,

    CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2009
    Zoltan G. Turi MD
    No abstract is available for this article. [source]


    Comparison of Endovenous Radiofrequency Versus 810 nm Diode Laser Occlusion of Large Veins in an Animal Model

    DERMATOLOGIC SURGERY, Issue 1 2002
    Robert A. Weiss MDArticle first published online: 27 FEB 200
    background. Endovenous occlusion using radiofrequency (RF) energy has been shown to be effective for the elimination of sapheno-femoral reflux and subsequent elimination of varicose veins. Recently, endovenous laser occlusion has been introduced with initial clinical reports indicating effective treatment for varicose veins. However, in our practice we note increased peri-operative hematoma and tenderness with the laser. Little is known regarding the mechanism of action of this new laser vein therapy. objective. To better understand the mechanism of action of endovenous laser vs. the endovenous RF procedure in the jugular vein of the goat model. methods. A bilateral comparison was performed using 810 nm diode laser transmitted by a bare-tipped optical fiber vs. the RF delivery by engineered electrodes with a temperature feedback loop using a thermocouple (Closure procedure) in three goat jugular veins. Immediate and one-week results were studied radiographically and histologically. Temperature measurements during laser treatment were performed by using an array of up to five thermocouples, spaced 2 mm apart, placed adjacent to a laser fiber tip during goat jugular vein treatment. results. Immediate findings showed that 100% of the laser-treated veins showed perforations by histologic examination and immediate contrast fluoroscopy. The RF-treated side showed immediate constriction with maintenance of contrast material within the vein lumen and no perforations. The difference in acute vein shrinkage was also dramatic as laser treatments resulted in vein shrinkage of 26%, while RF-treated veins showed a 77% acute reduction in diameter. At one week, extravasated blood that leaked into the surrounding tissue of laser treated veins acutely, continued to occupy space and impinge on surrounding structures including nerves. For the laser treatment, the highest average temperature was 729°C (peak temperature 1334°C) observed flush with the laser fiber tip, while the temperature feedback mechanism of the RF method maintains temperatures at the electrodes of 85°C. conclusion. Vein perforations, extremely high intravascular temperatures, failure to cause significant collagen shrinkage, and intact endothelium in an animal model justify a closer look at the human clinical application of the 810 nm endovenous laser technique. Extravasated blood impinging on adjacent structures may theoretically lead to increased peri-operative hematoma and tenderness. Further study and clinical investigation is warranted. [source]


    Embolization of Atrial Septal Occluder Device into the Pulmonary Artery: A Rare Complication and Usefulness of Live/Real Time Three-Dimensional Transthoracic Echocardiography

    ECHOCARDIOGRAPHY, Issue 6 2009
    Harvinder S. Dod M.D.
    Percutaneous closure of atrial septal defects (ASD) in adults has emerged as an alternative to surgery. We report a rare complication of an atrial septal occluder device embolization into the pulmonary artery which was detected by fluoroscopy and echocardiography. The potential usefulness of live/real time three-dimensional transthoracic echocardiography in the management of patients undergoing percutaneous ASD occlusion is described. (ECHOCARDIOGRAPHY, Volume 26, July 2009) [source]


    Transcatheter Intracardiac Echocardiography-Assisted Closure of Interatrial Shunts: Complications and Midterm Follow-Up

    ECHOCARDIOGRAPHY, Issue 2 2009
    Gianluca Rigatelli M.D.
    Objective: It has been suggested that intracardiac echocardiography (ICE) improves the safety and effectiveness of transcatheter device-based closure of interatrial shunts, but the impact of this technique on midterm follow-up is unknown. We sought to prospectively evaluate midterm follow-up results of ICE-aided transcatheter closure of interatrial shunts in adults. Methods: Over a 48-month period, we prospectively enrolled 140 consecutive patients (mean age 43 ± 15. 5 years, 98 females) who had been referred to our center for catheter-based closure of interatrial shunts. All patients were screened with transesophageal echocardiography (TEE) before the operation. Patients who met the inclusion criteria underwent ICE study and attempted closure. Immediate success rates, predischarge occlusion rates, complication rates, as well as fluoroscopy and procedural times, patients' radiological exposure, midterm complication rates, and midterm occlusion rates were evaluated. Results: One hundred patients out of 140 (71.4%) underwent an attempt at transcatheter closure. After ICE study and measurements, the TEE-planned device type and size was changed in 31 patients with patent foramen ovale whereas the TEE-planned device size was changed in 41 patients with atrial septal defect (globally 72%). Procedural success rate, predischarge occlusion rate, and complication rate were 99, 90.7, and 12%, respectively. On mean follow-up of 36.6 ± 14.8 months the follow-up occlusion rate was 96.5%. No aortic erosion or device thrombosis was observed. Conclusions: ICE-guided interatrial shunt transcatheter closure is safe and effective and appears to have excellent midterm results thus avoiding the complications caused by device oversizing, such as aortic erosion and device thrombosis. [source]


    The effect of bilateral glossopharyngeal nerve anaesthesia on swallowing in horses

    EQUINE VETERINARY JOURNAL, Issue 1 2005
    E. A. KLEBE
    Summary Reasons for performing study: Dysfunction of the glossopharyngeal nerve has been implicated as a cause of dysphagia in horses. However, recent studies have indicated that this is not the case. Objectives: To determine whether bilateral glossopharyngeal nerve anaesthesia would cause dysphagia in horses or result in measurable alterations in the timing, function, or sequence of swallowing. Methods: Swallowing was evaluated in 6 normal horses with and without bilateral glossopharyngeal nerve anaesthesia. Swallowing dynamics were assessed subjectively and objectively based on time from prehension of food until swallowing, number of tongue movements until initiation of swallowing, depth of bolus at the base of the tongue prior to initiation of swallow and evidence of tracheal aspiration using fluoroscopy and endoscopy. Results: There was no evidence of aspiration or dysphagia in horses before or after bilateral glossopharyngeal nerve block. No observed or measured differences in swallowing sequence or function could be detected in blocked compared to unblocked horses. However, there was a trend in blocked horses for the number of tongue pushes and the time to swallowing to be increased. Conclusions: Glossopharyngeal nerve function may not be essential for normal swallowing function in otherwise healthy horses. Potential relevance: Clinically, normal swallowing is not an appropriate test of glossopharyngeal nerve function and dysphagic horses should not be assumed to have glossopharyngeal nerve dysfunction. [source]


    Integrating modelling and experiments to assess dynamic musculoskeletal function in humans

    EXPERIMENTAL PHYSIOLOGY, Issue 2 2006
    J. W. Fernandez
    Magnetic resonance imaging, bi-plane X-ray fluoroscopy and biomechanical modelling are enabling technologies for the non-invasive evaluation of muscle, ligament and joint function during dynamic activity. This paper reviews these various technologies in the context of their application to the study of human movement. We describe how three-dimensional, subject-specific computer models of the muscles, ligaments, cartilage and bones can be developed from high-resolution magnetic resonance images; how X-ray fluoroscopy can be used to measure the relative movements of the bones at a joint in three dimensions with submillimetre accuracy; how complex 3-D dynamic simulations of movement can be performed using new computational methods based on non-linear control theory; and how musculoskeletal forces derived from such simulations can be used as inputs to elaborate finite-element models of a joint to calculate contact stress distributions on a subject-specific basis. A hierarchical modelling approach is highlighted that links rigid-body models of limb segments with detailed finite-element models of the joints. A framework is proposed that integrates subject-specific musculoskeletal computer models with highly accurate in vivo experimental data. [source]


    Neurolytic phenol blockade of the obturator nerve for severe adductor spasticity

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2010
    T. AKKAYA
    Background: In this study, we present the 3-month follow-up results of a retrospective analysis of obturator nerve (ON) phenol neurolysis performed between 2000 and 2007 in patients with adductor spasticity. Methods: The study was performed by retrospective investigation of the clinical follow-up results of 80 ON phenol treatments in 62 patients. Neurolysis using 5,10 ml 6% phenol was applied with the guidance of fluoroscopy and a peripheral nerve stimulator. Pain, spasticity and hygiene were evaluated and the hip abduction range of motion (ROM) was measured at the end of the first week and in the first, second and third months following the intervention. Results: The visual analogue scale scores decreased significantly in the first week, first month and the second month, but reached their initial values in the third month. A drastic increase in the ROM values was shown in hip abduction in the first week, first month and second month. An increase in the Ashworth Scale values was observed in the second and third months, but they did not reach their initial values. The hygiene score decreased drastically in the first week and the first and second months, but worsened in the third month. The success rate in nerve localization during ON neurolysis was 100%. Conclusion: ON phenol blockade with fluoroscopy and peripheral nerve stimulator guidance in patients with adductor spasticity led to a decrease in spasticity and pain with an increase in the ROM of the hip and better hygiene with an efficacy lasting for about 3 months. [source]


    Persistence of Pulmonary Vein Isolation After Robotic Remote-Navigated Ablation for Atrial Fibrillation and its Relation to Clinical Outcome

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2010
    STEPHAN WILLEMS M.D.
    Robotic Remote Ablation for AF. Aims: A robotic navigation system (RNS, HansenÔ) has been developed as an alternative method of performing ablation for atrial fibrillation (AF). Despite the growing application of RNS-guided pulmonary vein isolation (PVI), its consequences and mechanisms of subsequent AF recurrences are unknown. We investigated the acute procedural success and persistence of PVI over time after robotic PVI and its relation to clinical outcome. Methods and Results: Sixty-four patients (60.7 ± 9.8 years, 53 male) with paroxysmal AF underwent robotic circumferential PVI with 3-dimensional left atrial reconstruction (NavXÔ). A voluntary repeat invasive electrophysiological study was performed 3 months after ablation irrespective of clinical course. Robotic PVI was successful in all patients without complication (fluoroscopy time: 23.5 [12,34], procedure time: 180 [150,225] minutes). Fluoroscopy time demonstrated a gradual decline but was significantly reduced after the 30th patient following the introduction of additional navigation software (34 [29,45] vs 12 [9,17] minutes; P < 0.001). A repeat study at 3 months was performed in 63% of patients and revealed electrical conduction recovery in 43% of all PVs. Restudied patients without AF recurrence (n = 28) showed a significantly lower number of recovered PVs (1 (0,2) vs 2 (2,3); P = 0.006) and a longer LA-PV conduction delay than patients with AF recurrences (n = 12). Persistent block of all PVs was associated with freedom from AF in all patients. At 3 months, 67% of patients were free of AF, while reablation of recovered PVs led to an overall freedom from AF in 81% of patients after 1 year. Conclusion: Robotic PVI for PAF is safe, effective, and requires limited fluoroscopy while yielding comparable success rates to conventional ablation approaches with PV reconduction as a common phenomenon associated with AF recurrences. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1079-1084) [source]


    Effect of Left Ventricular Lead Concordance to the Delayed Contraction Segment on Echocardiographic and Clinical Outcomes after Cardiac Resynchronization Therapy

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2009
    JEFFREY W.H. FUNG M.D.
    Introduction: The optimal left ventricular (LV) pacing site for cardiac resynchronization therapy (CRT) is unclear. The current study aims to explore the clinical significance of LV lead concordance to delayed contraction segment in CRT. Methods and Results: Concordant LV lead position was defined as the lead tip located by fluoroscopy at or immediately adjacent to the LV segment with latest contraction determined by tissue Doppler imaging. Echocardiographic and clinical outcomes among 101 consecutive patients with or without concordant LV lead positions were compared. There was no significant difference in changes in LV volumes and clinical parameters between patients with concordant (n = 46) or nonconcordant (n = 55) LV lead positions at 3 and 6 months. In multivariate analysis, the baseline asynchrony index (,= 1.092, 95% CI: 1.050,1.114; P < 0.001), but not LV lead concordance, was the only independent predictor of LV reverse remodeling. By Cox regression analysis, ischemic etiology, and LV reverse remodeling, but not LV lead concordance, were independent predictors of mortality (,= 2.475, 95% CI: 1.183,5.178; P = 0.016, and ,= 0.272, 95% CI: 0.130,0.567; P < 0.001, respectively), cardiovascular hospitalization (,= 1.551, 95% CI: 1.032,2.333; P = 0.035, and ,= 0.460, 95% CI: 0.298,0.708; P < 0.001, respectively), and heart failure hospitalization (,= 0.486, 95% CI: 0.320,0.738; P = 0.001 for LV reverse remodeling). Conclusion: LV lead concordance to the delayed contraction segment may not be a major determining factor for favorable echocardiographic and clinical outcomes after CRT. [source]


    Pulmonary Vein Disconnection Using the LocaLisa Three-Dimensional Nonfluoroscopic Catheter Imaging System

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2003
    Laurent Macle M.D.
    Introduction: Catheter ablation for atrial fibrillation (AF) is associated with prolonged fluoroscopy times. We prospectively evaluated the use of the LocaLisa three-dimensional nonfluoroscopic catheter imaging system with the aim of reducing fluoroscopy times during pulmonary vein (PV) disconnection. Methods and Results: Fifty-two patients with AF (47 men and 5 women, mean age 53 ± 9 years) underwent disconnection of all four PVs guided by a circumferential mapping catheter. The LocaLisa navigation system was used for real-time three-dimensional nonfluoroscopic imaging of the circumferential mapping catheter and ablation catheter electrodes in 26 patients. Procedural parameters were compared with those of a control group consisting of 26 patients in whom only standard fluoroscopy was used. PV disconnection was performed similarly in both groups by circumferential ablation around the ostia, with the endpoint of disconnecting left atrium to PV breakthroughs. The cumulative duration of radiofrequency (RF) energy delivery, procedural time, and fluoroscopy time required for PV disconnection were compared. Successful disconnection was achieved in all PVs, without acute complications. There was no significant difference in cumulative RF energy delivery: 34.8 ± 11.4 minutes for the nonfluoroscopic imaging group versus 38.2 ± 10.5 minutes for the control group. The fluoroscopy time required for disconnection of all four PVs was significantly lower in the LocaLisa group than in the control group: 8.4 ± 4.3 minutes versus 23.7 ± 9.7 minutes (P < 0.0001). There also was a significant difference in the mean time taken for PV disconnection: 46.5 ± 12.0 minutes for the nonfluoroscopic imaging group versus 66.3 ± 18.9 minutes for the control group (P < 0.0001). Conclusion: By allowing continuous three-dimensional monitoring of ablation and mapping catheter position and orientation, the LocaLisa nonfluoroscopic imaging system significantly reduces fluoroscopy and PV disconnection times. (J Cardiovasc Electrophysiol, Vol. 14, pp. 693,697, July 2003) [source]


    Nonfluoroscopic Three-Dimensional Mapping for Arrhythmia Ablation: Tool or Toy?

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2000
    APICHAI KHONGPHATTHANAYOTHIN M.D.
    Arrhythmia Ahlation with Nonfluoroscopic 3D Mapping. Introduction: Conventional mapping and ablation rely on fluoroscopy, which can result in imprecise positioning of the ablation catheter and long fluoroscopic exposure times. We evaluated a nonfluoroscopic three-dimensional mapping system, termed CARTO, and compared the results of ablation using this technique with those of conventional mapping. Methods and Results: We compared the results of 88 arrhythmia ablations (79 patients) using CARTO with 100 ablations (94 patients) using the conventional technique. The ablations were separated into four groups: (1) AV nodal reentrant tachycardia (AVNRT); (2) atrial tachycardia/flutter; (3) ventricular tacbycardia (VT); and (4) bypass tract tachycardia. We compared the success rate, complications, and fluoroscopy and procedure times. Tbe ablation outcomes were excellent and comparable in all four types of the arrhythmias between the two techniques. Major complications included one cardiac tamponade in each group and one second-degree AV block in the conventional group. Fluoroscopy time was shorter using the CARTO technique: 10 ± 7 versus 27 ± 15 minutes for AVNRT (P < 0.01), 18 ± 17 versus 44 ± 23 minutes for atrial tachycardia and flutter (P < 0.01), 15 ± 12 versus 34 ± 31 minutes for VT (P < 0.05), and 21 ± 14 versus 53 ± 32 minutes for bypass tract tachycardia (P < 0.01). Procedure times were similar except for the bypass tract patients, wbich was shorter in the CARTO group, 4 ± 1.3 versus 5.5 ± 2.5 hours (P < 0.01). Conclusion: The electroanatomic three-dimensional mapping technique reduced fluoroscopy time and resulted in excellent outcome without increasing the procedure time. [source]


    Transvenous Parasympathetic Nerve Stimulation in the Inferior Vena Cava and Atrioventricular Conduction

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2000
    PATRICK SCHAUERTE M.D.
    Parasympathetic Stimulation in the Inferior Vena Cava. Introduction: In previous reports, we demonstrated a technique for parasympathetic nerve stimulation (PNS) within the superior vena cava, pulmonary artery, and coronary sinus to control rapid ventricular rates during atrial fibrillation (AF). In this report, we describe another vascular site, the inferior vena cava (IVC), at which negative dromotropic effects during AF could consistently he obtained. Moreover, stimulation at this site also induced dual AV nodal electrophysiology. Methods and Results: PNS was performed in ten dogs using rectangular stimuli (0.1 msec/20 Hz) delivered through a catheter with an expandable electrode basket at its tip. Within 3 minutes and without using fluoroscopy, the catheter was positioned at an effective PNS site in the IVC at the junction of the right atrium. AF was induced and maintained by rapid atrial pacing. During stepwise increase of the PNS voltage from 2 to 34 V, a graded response of ventricular rate slowing during AF was observed (266 ± 79 msec without PNS vs 1,539 ± 2,460 msec with PNS at 34 V; P = 0.005 by analysis of variance), which was abolished by atropine and blunted by hexamethonium. In three animals, PNS was performed during sinus rhythm. Dual AV nodal electrophysiology was present in 1 of 3 dogs in control, whereas with PNS, dual AV nodal electrophysiology was observed in all three dogs. PNS did not significantly change sinus rate or arterial blood pressure during ventricular pacing. Conclusion: Stable and consistent transvenous electrical stimulation of parasympathetic nerves innervating the AV node can be achieved in the IVC, a transvenous site that is rapidly and readily accessible. The proposed catheter approach for PNS can be used to control ventricular rate during AF in this animal model. [source]


    Intravascular ultrasound-guided central vein angioplasty and stenting without the use of radiographic contrast agents

    JOURNAL OF CLINICAL ULTRASOUND, Issue 4 2008
    Ray Matthews MD
    Abstract Patients with contraindications to iodinated radiographic contrast agents present a significant challenge during endovascular intervention. A 46-year-old man with end-stage renal disease and a normally functioning left upper extremity arteriovenous fistula presented with severe left arm edema. The patient's history included repeated severe anaphylactoid reactions with severe respiratory distress upon exposure to iodinated contrast. In an attempt to avoid the use of iodinated contrast, angioplasty and stent placement of a severe central venous stenosis were performed using only fluoroscopy and intravascular sonography. In patients unable to receive iodinated contrast secondary to anaphylactoid reactions, intravascular sonography can be used to guide angioplasty and stenting of central venous stenosis. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008. [source]


    Single-session, graded esophageal dilation without fluoroscopy in outpatients with lower esophageal (Schatzki's) rings: A prospective, long-term follow-up study

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 5 2007
    Spiros N Sgouros
    Abstract Background:, Distal esophageal (Schatzki's) ring is a frequent cause of dysphagia. Bougienage is generally effective but relapses are common. The aim of this study was to evaluate the safety and long-term efficacy of single-session graded esophageal dilation with Savary dilators, without fluoroscopic guidance, in outpatients who presented with Schatzki's ring. Methods:, The study was performed on 44 consecutive patients with symptomatic Schatzki's ring, detected endoscopically and/or radiologically. Graded esophageal dilation was performed as an outpatient procedure in a single session with Savary dilators, without fluoroscopic guidance. After appropriate assessment with esophageal manometry and 24 h ambulatory pHmetry, patients with documented gastroesophageal reflux disease (GERD) were treated with omeprazole continuously. All results, including clinical follow up and technical aspects of bougienage, were recorded prospectively. The necessity for re-dilation after documentation of the ring with endoscopy and/or radiology was considered as a relapse of the ring. Results:, In four (9%) patients a second session was necessary to ensure complete symptom relief. Two (4.5%) patients developed post-dilation bacteremia and were managed with antibiotics as outpatients. Patients with (n = 14) or without (n = 30) GERD were comparable with respect to sex, age, body mass index, smoke and ethanol consumption, diameter of the esophageal lumen at the level of the ring, resting lower esophageal sphincter pressure, duration of dysphagia, need for taking antacids during the follow-up period, and duration of follow-up. There was no recurrence of the ring in patients with GERD during a mean follow-up period of 43.8 ± 9.3 months (range 27,62 months); however, in patients without GERD, during a mean follow-up period of 40.6 ± 12.2 months (range 10,58 months), 32% of patients relapsed after a mean 19.9 ± 10.6 months (P = 0.04). Conclusions:, Single-session graded esophageal dilation with large caliber Savary dilators without fluoroscopic guidance can be safely used for the symptomatic relief in patients with lower esophageal (Schatzki's) rings. GERD should be treated if present in order to prevent a symptomatic recurrence of the ring. [source]


    Image-guided and -monitored renal artery stenting using only MRI

    JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 5 2006
    Daniel R. Elgort PhD
    Abstract Purpose To demonstrate the ability of a unique interventional MR system to be used safely and effectively as the only imaging modality for all phases of MR-guided stent-supported angioplasty. Materials and Methods An experimental disease model of renal stenosis was created in six pigs. An interventional MR system, which employed previously reported tools for real-time catheter tracking with automated scan-plane positioning, adaptive image parameters, and radial true,FISP imaging with steady-state precession (True-FISP) imaging coupled with a high-speed reconstruction technique, was then used to guide all phases of the intervention, including: guidewire and catheter insertion, stent deployment, and confirmation of therapeutic success. Pre- and postprocedural X-ray imaging was used as a gold standard to validate the experimental results. Results All of the stent-supported angioplasty interventions were a technical success and were performed without complications. The average postoperative residual stenosis was 14.9%. The image guidance enabled the stents to be deployed with an accuracy of 0.98 ± 0.69 mm. Additionally, using this interventional MRI system to guide renal artery stenting significantly reduces the procedure time, as compared to using X-ray fluoroscopy. Conclusion This study has clearly demonstrated the first successful treatment of renal artery stenting in an experimental animal model solely under MRI guidance and monitoring. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source]


    Balloon sizing and transcatheter closure of acute atrial septal defects guided by magnetic resonance fluoroscopy: Assessment and validation in a large animal model,

    JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2005
    Simon Schalla MD
    Abstract Purpose To quantitatively assess atrial septal defects (ASDs) with small shunts using MRI followed by transcatheter closure monitored by MR fluoroscopy. Materials and Methods Acute ASDs were created in 14 pigs under x-ray fluoroscopy. Six animals were studied in order to select MR-compatible delivery systems and imaging strategies. ASDs in eight animals were examined with balloon sizing under MR fluoroscopy, flow measurements, and contrast media injections, after which transcatheter closure was performed under MR fluoroscopy. The delivery system was assembled from commercially available materials. Results The ratio of pulmonary to systemic flow (Qp/Qs) was reduced from 1.23 ± 0.15 before ASD closure to 1.07 ± 0.11 after ASD closure (P < 0.001). In two out of eight animals Qp/Qs was close to 1.0 before closure despite the presence of defects >15 mm. The ASDs were measurable with MR balloon sizing in all of the animals. Balloon sizing was identical with MR (16.9 ± 2.3 mm) and x-ray fluoroscopy (17.1 ± 1.3 mm). The in-house-assembled delivery system allowed successful placement of closure devices under MR guidance. Conclusion Assessment and closure of small shunts with MR fluoroscopy is feasible. A barrier to the rapid implementation of transcatheter closure in patients is uncertainty about the MR safety of guidewires and device delivery systems. J. Magn. Reson. Imaging 2005;21:204,211. © 2005 Wiley-Liss, Inc. [source]


    MR-guided biopsy of musculoskeletal lesions in a low-field system

    JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 5 2001
    Claudius W. Koenig MD
    Abstract Thirty magnetic resonance (MR)-guided biopsies were obtained from 20 skeletal and 10 soft-tissue lesions in 31 patients using an open 0.2 T MR system equipped with interventional accessories. The results from aspiration (N = 3), core biopsy (N = 15), and transcortical trephine biopsy (N = 12) were evaluated for accuracy and clinical efficacy. Specimens were successfully obtained from 29 patients. Results were clinically effective in 23 patients, rated definitive in 16, nonconclusive in 9, and unspecific in 2 patients. A false diagnosis due to sampling error occurred in 2 patients, and biopsy sampling was impossible in one case. The best diagnostic yield was achieved from nontranscortical biopsies of osteolytic or soft-tissue masses. Results from transcortical biopsies were less specific due to the predominance of benign lesions. MR fluoroscopy for needle guidance was applied in 13 patients. Complete needle placement inside the magnet could be performed in 16 patients. MR-guided biopsy using an open low-field MR imager is feasible and clinically effective and will become a valuable tool in the management of musculoskeletal lesions. J. Magn. Reson. Imaging 2001;13:761,768. © 2001 Wiley-Liss, Inc. [source]


    Fluoroscopic guidance of Arndt endobronchial blocker placement for single-lung ventilation in small children

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2008
    B. MARCINIAK
    Background: Thoracoscopic surgery may require single-lung ventilation (SLV) in infants and small children. A variety of balloon-tipped endobronchial blockers exist but the placement is technically challenging if the size of the tracheal tube does not allow the simultaneous passage of the fibreoptic scope and the endobronchial blocker. This report describes a technique for endobronchial blocker insertion using fluoroscopic guidance in children undergoing SLV. Methods: After approval from the local Medical Ethics Committee and parental consent, 18 patients aged 2 years or younger scheduled for thoracic surgery requiring SLV were prospectively included. Following induction of anesthesia, a 5 Fr endobronchial blocker (Cook® Arndt endobronchial blocker) was inserted first into the trachea under direct laryngoscopy. Correct placement in the main bronchus was assessed by fluoroscopy and tracheal intubation next to the endobronchial blocker. Optimal position and balloon inflation was verified using a fibreoptic scope. The duration and number of insertion attempts as well as age, weight and size of the tracheal tube were recorded. Results: Eighteen patients were studied. Median (range) age and weight were 12 (0.2,24) months and 11.2 (4,15) kg, respectively. SLV was successfully achieved in all patients using a 5 Fr endobronchial blocker outside a 3.5,4.5 mm ID tracheal tube within 11.2 (±2.2) min. No side effects were observed during the procedure. Conclusion: Fluoroscopic-guided insertion of extraluminal endobronchial blocker is an effective and reliable tool to place Arndt endobronchial blockers in small children. [source]


    Management of persistent post-dural puncture headache after repeated epidural blood patch

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2007
    K.-Y. Ho
    We report a case of persistent post-dural puncture headache (PDPH) in a patient despite two epidural blood patches (EBPs). Successful resolution of headache was achieved with a third EBP performed under computed tomography (CT) guidance. A 38-year-old female had a total abdominal hysterectomy under combined spinal-epidural anesthesia with no complications. After surgery, she developed a postural headache consistent with PDPH. The first EBP was performed by injecting autologous blood through the epidural catheter that was in situ. The second EBP was performed under fluoroscopy. The patient continued to have a persistent headache. A computed tomography (CT) myelogram demonstrated cerebrospinal fluid (CSF) leak at L3,4 level. A ,directed' CT-guided blood patch was then performed successfully with resolution of the headache. [source]


    Clinical trial: a randomized trial comparing fluoroscopy guided percutaneous technique vs. endoscopic ultrasound guided technique of coeliac plexus block for treatment of pain in chronic pancreatitis

    ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2009
    D. SANTOSH
    Summary Background, Coeliac plexus block (CPB) is a management option for pain control in chronic pancreatitis. CPB is conventionally performed by percutaneous technique with fluoroscopic guidance (PCFG). Endoscopic ultrasound (EUS) is increasingly used for CPB as it offers a better visualization of the plexus. There are limited data comparing the two modalities. Aim, To compare the pain relief in chronic pancreatitis among patients undergoing CPB either by PCFG technique or by EUS guided technique. Methods, Chronic pancreatitis patients with abdominal pain requiring daily analgesics for more than 4 weeks were included. Fifty six consecutive patients (41 males, 15 females) participated in the study. EUSG-CPB was performed in 27 and PCFG-CPB in 29 patients. In both the groups, 10 mL of Bupivacaine (0.25%) and 3 mL of Triamcinolone (40 mg) were given on both sides of the coeliac artery through separate punctures. Results, Pre and post procedure pain scores were obtained using a 0-10 visual analogue scale. Improvement in pain scores was seen in 70% of subjects undergoing EUS-CPB and 30% in Percutaneous- block group (P = 0.044). Conclusions, EUS-guided coeliac block appears to be better than PCFG-CPB for controlling abdominal pain in patients with chronic pancreatitis. [source]


    Uterus masculinus: an unusual complication in a case of feline urethral obstruction

    JOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 1 2006
    Gabriella Sfiligoi DVM
    Abstract A 6-year-old, male castrated domestic short hair cat presented for urethral obstruction. Despite passage of a urinary catheter, urine could not be drained through the catheter, but urine flow was noted around the catheter. Special imaging studies, including ultrasound and fluoroscopy, revealed that the catheter had been passed into an abnormal small bicornuate structure that entered the urethra from dorsally within the pelvic canal. This structure was believed to be a uterus masculinus or remnants of the Mullerian ducts. The anomalous structure was not felt to be related to the cause of the urethral obstruction, but was simply an incidental finding which resulted in difficult catheterization. [source]


    3D fluoroscopy with real-time 3D non-cartesian phased-array contrast-enhanced MRA,

    MAGNETIC RESONANCE IN MEDICINE, Issue 2 2006
    Ethan Brodsky
    Abstract For optimized CE-MRA of the chest and abdomen, the scan time and breath-hold must be coordinated with the arrival of contrast. A 3D fluoroscopy system is demonstrated that performs real-time 3D projection reconstruction acquisition, reconstruction, and visualization using only the standard scanner hardware and operator console workstation. Unlike 2D fluorotriggering techniques, no specification of a monitoring slab or careful placement of the imaging volume is required. 3DPR data are acquired continuously throughout the examination using an eight-channel receiver and 1 s interleaved subframes. The data are reconstructed using 1 s segments for real-time monitoring with 0.8-cm isotropic spatial resolution over the entire torso, allowing full-volume axial, coronal, and sagittal MIPs to be displayed simultaneously with minimal latency. The system later uses the same scan data to generate high-spatial-resolution time-resolved sequences of the breath-hold interval. The 3D fluoroscopy system was validated on phantoms and human volunteers. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc. [source]


    Coiling of lumbar epidural catheters

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2002
    Y. J. Lim
    Background: The difficulties in threading an epidural catheter to vertebral levels remote to the puncture level have been well documented. This study was undertaken to determine the length that a single orifice epidural catheter can be threaded into the lumbar space without coiling (coiling length), and whether this is affected by the direction of the epidural needle bevel. Methods: Forty-five young male patients scheduled for surgery under epidural analgesia were enrolled. The epidural space was identified using a midline approach at the L2,3 or L3,4 interspace with the loss of resistance to air technique. A 19-G single-orifice epidural catheter (Flextip PlusTM, Arrow International, Inc, Reading, PA, USA) was inserted through a Tuohy needle oriented either cephalad (n=20) or caudad (n=25). During insertion, the path and the position of the catheter tip was determined by fluoroscopy using iohexol dye. Results: The median coiling length was 2.8 cm, ranging from 1.0 to 8.0 cm. Only 13% of epidural catheters could be threaded 4 cm beyond the tip of the needle without coiling. No significant difference was found in coiling length between the cephalad group (2.9 cm) and the caudad group (2.5 cm). Conclusion: This study demonstrates that coiling length is independent of whether the bevel of the Tuohy needle is directed cephalad or caudad. We recommend that an optimal insertion depth of an end-hole single orifice catheter is 3 cm. [source]


    Linear Radiofrequency Microcatheter Ablation Guided by Phased Array Intracardiac Echocardiography Combined with Temperature Decay

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2009
    DAVID KEANE M.D., Ph.D.
    Background:Fluoroscopy-guided catheter placement is limited in its ability to determine electrode-endocardial contact and involves radiation exposure. We hypothesized that (1) intracardiac echocardiography (ICE) would provide superior assessment of linear electrode contact compared to fluoroscopy and (2) slow temperature decay upon discontinuation of the radiofrequency current (time for temperature to fall 90% after a 10-second test application of the radiofrequency current T90) would indicate optimal electrode-myocardial contact. Methods:Sixty endocardial lesions were created in the atria and ventricles of six goats by simultaneous delivery of the radiofrequency current through two linear electrodes of a microcatheter with a central interelectrode thermocouple. Catheter placement was guided by fluoroscopy. A 7.5-MHz ICE transducer in the right atrium or ventricle assessed electrode contact. T90 and previously reported parameters of electrode contact and lesion formation were recorded. Histomorphometry was performed on the lesions. Results:T90 was 4.27 ± 4.98 seconds. Lesion depth significantly correlated with ICE assessment of electrode contact (r = 0.56, P = 0.001); T90 upon radiofrequency current offset (r = 0.48, P = 0.008), impedance fall upon radiofrequency current onset (r = 0.37, P = 0.008), bipolar pacing threshold preablation (r =,0.56, P = 0.001), bipolar electrogram amplitude preablation (r = 0.43, P = 0.02), but not with fluoroscopic assessment of the electrode contact (r = 0.18, n.s.). For the prediction of achieving a lesion depth of >2 mm, a T90 of >4.0 seconds yielded a specificity of 86% and a sensitivity of 52%, ICE yielded a specificity and sensitivity of 58% and 68%, respectively, while the specificity and sensitivity of fluoroscopy were 26% and 68%, respectively. Both ICE and T90 provide additional clinical relevance during guidance of cardiac microcatheter ablation. [source]


    Search for the Optimal Right Ventricular Pacing Site: Design and Implementation of Three Randomized Multicenter Clinical Trials

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 4 2009
    GERRY KAYE M.D.
    Background: The optimal site to permanently pace the right ventricle (RV) has yet to be determined. To address this issue, three randomized prospective multicenter clinical trials are in progress comparing the long-term effects of RV apical versus septal pacing on left ventricular (LV) function. The three trials are Optimize RV Selective Site Pacing Clinical Trial (Optimize RV), Right Ventricular Apical and High Septal Pacing to Preserve Left Ventricular Function (Protect Pace), and Right Ventricular Apical versus Septal Pacing (RASP). Methods: Patients that require frequent or continuous ventricular pacing are randomized to RV apical or septal pacing. Optimize RV excludes patients with LV ejection fraction <40% prior to implantation, whereas the other trials include patients regardless of baseline LV systolic function. The RV septal lead is positioned in the mid-septum in Optimize RV, the high septum in Protect Pace, and the mid-septal inflow tract in RASP. Lead position is confirmed by fluoroscopy in two planes and adjudicated by a blinded panel. The combined trials will follow approximately 800 patients for up to 3 years. Results: The primary outcome in each trial is LV ejection fraction evaluated by radionuclide ventriculography or echocardiography. Secondary outcomes include echo-based measurements of ventricular/atrial remodeling, 6-minute hall walk distance, brain natriuretic peptide levels, and clinical events (atrial tachyarrhythmias, heart failure, stroke, or death). Conclusion: These selective site ventricular pacing trials should provide evidence of the importance of RV pacing site in the long-term preservation of LV function in patients that require ventricular pacing and help to clarify the optimal RV pacing site. [source]