Science.gov

Sample records for 2-french radiofrequency catheter

  1. The use of radiofrequency catheter ablation to cure dilated cardiomyopathy.

    PubMed

    Schmidt, S B; Lobban, J H; Reddy, S; Hoelper, M; Palmer, D L

    1997-01-01

    Incessant supraventricular tachycardia can cause a dilated cardiomyopathy. This article discusses the case of a 55-year-old woman whose cardiomyopathy was reversed when she underwent successful radiofrequency catheter ablation of a unifocal atrial tachycardia. PMID:9197188

  2. Successful Management of Atrio-Esophageal Fistula after Cardiac Radiofrequency Catheter Ablation

    PubMed Central

    Shim, Hun Bo; Kim, Chilsung; Kim, Hong-Kwan

    2013-01-01

    An increase in cardiac radiofrequency catheter ablation for treating refractory atrial fibrillation has resulted in an increased prevalence of complications. Among numerous complications of radiofrequency catheter ablation, atrio-esophageal fistula, although rare, is known to have fatal results. We report a case of successful management of an atrio-esophageal fistula as a complication of cardiac radiofrequency catheter ablation. PMID:23614102

  3. Radiofrequency catheter ablation of accessory pathways in infants.

    PubMed Central

    Benito, F.; Sánchez, C.

    1997-01-01

    OBJECTIVE: To evaluate the indications, results and complications of radiofrequency catheter ablation in small infants with supraventricular tachycardia due to an accessory atrioventricular pathway. METHODS: Five infants less than 9 months old underwent radiofrequency catheter ablation of accessory pathways. Ablation was done for medically refractory tachyarrhythmia associated with aborted sudden death in two patients, left ventricular dysfunction in one, failure of antiarrhythmic drugs in one, and planned cardiac surgery in one. All five patients underwent a single successful procedure. Three left free wall pathways were ablated by transseptal approach, a right posteroseptal pathway was ablated from the inferior vena cava, and a left posteroseptal pathway was approached from the inferior vena cava into the coronary sinus. A deflectable 5F bipolar electrode catheter with a 3 mm tip was used. RESULTS: A sudden increment in impedance indicative of coagulum formation was observed in two procedures. One patient developed a transient ischaemic complication after ablation of a left lateral accessory pathway by transseptal approach. This patient had mild pericardial effusion after the procedure. Moderate pericardial effusion was also noted in another patient. After a mean follow up of 18.4 months all patients are symptom free without treatment. CONCLUSIONS: Radiofrequency catheter ablation can be performed successfully in infants. Temperature monitoring in 5F ablation catheters would be desirable to prevent the development of coagulum. Echocardiography must be performed after the ablation procedure to investigate pericardial effusion. Images PMID:9326990

  4. Novel catheter enabling simultaneous radiofrequency ablation and optical coherence reflectometry

    PubMed Central

    Herranz, D.; Lloret, Juan; Jiménez-Valero, Santiago; Rubio-Guivernau, J. L.; Margallo-Balbás, Eduardo

    2015-01-01

    A novel radiofrequency ablation catheter has been developed with integrated custom designed optics, enabling real-time monitoring of radiofrequency ablation procedures through polarization-sensitive optical coherence reflectometry. The optics allow for proper tissue illumination through a view-port machined in the catheter tip, thus providing lesion depth control over the RF ablation treatment. The system was verified in an in-vitro model of swine myocardium. Optical performance and thermal stability was confirmed after more than 25 procedures, without any damage to the optical assembly induced by thermal stress or material degradation. The use of this catheter in RF ablation treatments may make possible to assess lesion depth during therapy, thus translating into a reduction of potential complications on the procedure. PMID:26417499

  5. Irrigated tip catheters for radiofrequency ablation in ventricular tachycardia.

    PubMed

    Müssigbrodt, Andreas; Grothoff, Matthias; Dinov, Borislav; Kosiuk, Jedrzej; Richter, Sergio; Sommer, Philipp; Breithardt, Ole A; Rolf, Sascha; Bollmann, Andreas; Arya, Arash; Hindricks, Gerhard

    2015-01-01

    Radiofrequency (RF) ablation with irrigated tip catheters decreases the likelihood of thrombus and char formation and enables the creation of larger lesions. Due to the potential dramatic consequences, the prevention of thromboembolic events is of particular importance for left-sided procedures. Although acute success rates of ventricular tachycardia (VT) ablation are satisfactory, recurrence rate is high. Apart from the progress of the underlying disease, reconduction and the lack of effective transmural lesions play a major role for VT recurrences. This paper reviews principles of lesion formation with radiofrequency and the effect of tip irrigation as well as recent advances in new technology. Potential areas of further development of catheter technology might be the improvement of mapping by better substrate definition and resolution, the introduction of bipolar and multipolar ablation techniques into clinical routine, and the use of alternative sources of energy. PMID:25705659

  6. Irrigated Tip Catheters for Radiofrequency Ablation in Ventricular Tachycardia

    PubMed Central

    Grothoff, Matthias; Dinov, Borislav; Kosiuk, Jedrzej; Richter, Sergio; Sommer, Philipp; Breithardt, Ole A.; Bollmann, Andreas; Arya, Arash; Hindricks, Gerhard

    2015-01-01

    Radiofrequency (RF) ablation with irrigated tip catheters decreases the likelihood of thrombus and char formation and enables the creation of larger lesions. Due to the potential dramatic consequences, the prevention of thromboembolic events is of particular importance for left-sided procedures. Although acute success rates of ventricular tachycardia (VT) ablation are satisfactory, recurrence rate is high. Apart from the progress of the underlying disease, reconduction and the lack of effective transmural lesions play a major role for VT recurrences. This paper reviews principles of lesion formation with radiofrequency and the effect of tip irrigation as well as recent advances in new technology. Potential areas of further development of catheter technology might be the improvement of mapping by better substrate definition and resolution, the introduction of bipolar and multipolar ablation techniques into clinical routine, and the use of alternative sources of energy. PMID:25705659

  7. Radiofrequency catheter septal ablation for hypertrophic obstructive cardiomyopathy in children

    PubMed Central

    Emmel, M.; Sreeram, N.

    2005-01-01

    Background The definitive therapeutic options for symptomatic obstructive cardiomyopathy in childhood are restricted. At present, extensive surgical myectomy is the only procedure that is of proven benefit. Patients and Methods Three patients, aged 5, 11 and 17 years, respectively, with progressive hypertrophic obstructive cardiomyopathy and increasing symptoms were considered for radiofrequency catheter septal ablation. The peak Doppler gradient recorded on several occasions ranged between 50 to 90mmHg. Via a femoral arterial approach, the His bundle was initially plotted and marked using the LocaLisa navigation system. Subsequently, using a cooled tip catheter a series of lesions were placed in the hypertrophied septum, taking care to stay away from the His bundle. A total of 17, 50 and 45 lesions were applied in the three patients. In one case, the procedure was complicated by two episodes of ventricular fibrillation requiring DC cardioversion but without any neurological sequelae. Results The preablation peak-to-peak gradient between left ventricle and aorta was 50 mmHg, 60 mmHg and 60 mmHg, respectively, and remained unchanged immediately after the procedure. All patients were discharged from hospital 48 hours later. Serial measurement of serum troponin T and CK-MB isoenzyme confirmed significant myocardial necrosis. Follow-up echocardiography both at seven days and at six weeks postablation confirmed a beneficial haemodynamic result, with reduction of left ventricular outflow obstruction and relief of symptoms. Conclusion In young children, in whom alcohol-induced septal ablation is not an option, radiofrequency catheter ablation offers an alternative to surgery, with the benefits of repeatability and a lower risk of procedure-related permanent AV block. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:25696442

  8. Determination of lesion size by ultrasound during radiofrequency catheter ablation.

    PubMed

    Awad, S; Eick, O

    2003-01-01

    The catheter tip temperature that is used to control the radiofrequency generator output poorly correlates to lesion size. We, therefore, evaluated lesions created in vitro using a B-mode ultrasound imaging device as a potential means to assess lesion generation during RF applications non-invasively. Porcine ventricular tissue was immersed in saline solution at 37 degrees C. The catheter was fixed in a holder and positioned in a parallel orientation to the tissue with an array transducer (7.5 MHz) app. 3 cm above the tissue. Lesions were produced either in a temperature controlled mode with a 4-mm tip catheter with different target temperatures (50, 60, 70 and 80 degrees C, 80 W maximum output) or in a power controlled mode (25, 50 and 75 W, 20 ml/min irrigation flow) using an irrigated tip catheter. Different contact forces (0.5 N, 1.0 N) were tested, and RF was delivered for 60 s. A total of 138 lesions was produced. Out of these, 128 could be identified on the ultrasound image. The lesion depth and volume was on average 4.1 +/- 1.6 mm and 52 +/- 53 mm3 as determined by ultrasound and 3.9 +/- 1.7 mm and 52 +/- 55 mm3 as measured thereafter, respectively. A linear correlation between the lesion size determined by ultrasound and that measured thereafter was demonstrated with a correlation coefficient of r = 0.87 for lesion depth and r = 0.93 for lesion volume. We conclude that lesions can be assessed by B-mode ultrasound imaging. PMID:12910859

  9. Catheter ablation of atrioventricular accessory pathways by radiofrequency current.

    PubMed

    Wang, L; Hu, D; Ding, Y

    1993-12-15

    Tachycardias mediated by atrioventricular accessory pathways, which are refractory to antiarrhythmic drug therapy have been treated both by surgery and by catheter ablation with high energy direct current shock. These procedures have variable success rates and substantial associated morbidity and mortality. Radiofrequency ablation, a newer, low-energy technique is potentially safer and more effective. Of 110 patients with 117 accessory pathways, 101 were located on the left side and 16 on the right. Accessory pathway conduction was abolished permanently in 101 (91.8%) patients. VA conduction dissociation and VA decremental conduction were found in 88 and 13 successful patients, respectively. Four (3.9%) patients with decremental VA conduction suffered arrhythmia recurrence after a mean of 8 months follow-up. Complications developed in two patients including right femoral vein thrombosis and left ventricular insufficiency. There were no deaths from the procedure. We conclude that radiofrequency current ablation is a safe and effective interventional modality for patients with symptomatic tachycardias mediated by atrioventricular accessory pathways. PMID:8112920

  10. Catheter ablation of atrial fibrillation: Radiofrequency catheter ablation for redo procedures after cryoablation

    PubMed Central

    Kettering, Klaus; Gramley, Felix

    2013-01-01

    AIM: To evaluate the effectiveness of two different strategies using radiofrequency catheter ablation for redo procedures after cryoablation of atrial fibrillation. METHODS: Thirty patients (paroxysmal atrial fibrillation: 22 patients, persistent atrial fibrillation: 8 patients) had to undergo a redo procedure after initially successful circumferential pulmonary vein (PV) isolation with the cryoballoon technique (Arctic Front Balloon, CryoCath Technologies/Medtronic). The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy (CARTO; Biosense Webster) depending on the intra-procedural findings. After discharge, patients were scheduled for repeated visits at the arrhythmia clinic. A 7-day Holter monitoring was performed at 3, 12 and 24 mo after the ablation procedure. RESULTS: During the redo procedure, a mean number of 2.9 re-conducting pulmonary veins (SD ± 1.0 PVs) were detected (using a circular mapping catheter). In 20 patients, a segmental approach was sufficient to eliminate the residual pulmonary vein conduction because there were only a few recovered pulmonary vein fibres. In the remaining 10 patients, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction. All recovered pulmonary veins could be isolated successfully again. At 2-year follow-up, 73.3% of all patients were free from an arrhythmia recurrence (22/30). There were no major complications. CONCLUSION: In patients with an initial circumferential pulmonary vein isolation using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. PMID:24009817

  11. In Vivo Evaluation and Proof of Radiofrequency Safety of a Novel Diagnostic MR-Electrophysiology Catheter

    PubMed Central

    Weiss, Steffen; Wirtz, Daniel; David, Bernd; Krueger, Sascha; Lips, Oliver; Caulfield, Dennis; Pedersen, Steen Fjord; Bostock, Julian; Razavi, Reza; Schaeffter, Tobias

    2013-01-01

    An MR-electrophysiology (EP) catheter is presented that provides full diagnostic EP functionality and a high level of radiofrequency safety achieved by custom-designed transmission lines. Highly resistive wires transmit intracardiac electrograms and currents for intracardiac pacing. A transformer cable transmits the localization signal of a tip coil. Specific absorption rate simulations and temperature measurements at 1.5 T demonstrate that a wire resistance > 3 kΩ/m limits dielectric heating to a physiologically irrelevant level. Additional wires do not increase tip specific absorption rate significantly, which is important because some clinical catheters require up to 20 electrodes. It is further demonstrated that radiofrequency-induced and pacing-induced resistive heating of the wires is negligible under clinical conditions. The MR-EP catheters provided uncompromised recording of electrograms and cardiac pacing in combination with a standard EP recorder in MR-guided in vivo EP studies, and the tip coil enabled fast and robust catheter localization. In vivo temperature measurements during such a study did not detect any device-related heating, which confirms the high level of safety of the catheter, whereas unacceptable heating was found with a standard EP catheter. The presented concept for the first time enables catheters with full diagnostic EP functionality and active tracking and at the same time a sufficient level of radiofrequency safety for MRI without specific absorption rate-related limitations. PMID:21337409

  12. Radiofrequency catheter ablation of the atrioventricular junction from the left ventricle

    SciTech Connect

    Sousa, J.; el-Atassi, R.; Rosenheck, S.; Calkins, H.; Langberg, J.; Morady, F. )

    1991-08-01

    The purpose of this study was to describe a new technique for catheter ablation of the atrioventricular junction using radiofrequency energy delivered in the left ventricle. Catheter ablation of the atrioventricular (AV) junction using a catheter positioned across the tricuspid annulus was unsuccessful in eight patients with a mean {plus minus} SD age of 51 {plus minus} 19 years who had AV nodal reentry tachycardia (three patients), orthodromic tachycardia using a concealed midseptal accessory pathway, atrial tachycardia, atrial flutter (two patients), or atrial fibrillation. Before attempts at catheter ablation of the AV junction, each patient had been refractory to pharmacological therapy, and four had failed attempts at either catheter modification of the AV node using radiofrequency energy or surgical and catheter ablation of the accessory pathway. Conventional right-sided catheter ablation of the AV junction using radiofrequency energy in six patients and both radiofrequency energy and direct current shocks in two patients was ineffective. The mean amplitude of the His bundle potential recorded at the tricuspid annulus at the sites of unsuccessful AV junction ablation was 0.1 {plus minus} 0.08 mV, with a maximum His amplitude of 0.03-0.28 mV. A 7F deflectable-tip quadripolar electrode catheter with a 4-mm distal electrode was positioned against the upper left ventricular septum using a retrograde aortic approach from the femoral artery. Third-degree AV block was induced in each of the eight patients with 20-36 W applied for 15-30 seconds. The His bundle potential at the sites of successful AV junction ablation ranged from 0.06 to 0.99 mV, with a mean of 0.27 {plus minus} 0.32 mV. There was no rise in the creatine kinase-MB fraction and no complications occurred. An intrinsic escape rhythm of 30-60 beats/min was present in seven of the eight patients.

  13. Radiofrequency catheter ablation in pediatric patients with supraventricular arrhythmias.

    PubMed

    Rhodes, L A; Lobban, J H; Schmidt, S B

    1995-01-01

    Radiofrequency (RF) ablation of foci leading to abnormal cardiac rhythms is rapidly becoming the procedure of choice in the management of arrhythmias in adults. This report reviews our initial experience with RF ablation in the pediatric population. PMID:8533398

  14. Radiofrequency catheter ablation in patients with Wolff-Parkinson-White syndrome.

    PubMed Central

    Thakur, R K; Klein, G J; Yee, R

    1994-01-01

    OBJECTIVE: To report on the experience with radiofrequency catheter ablation of accessory atrioventricular pathways in patients with Wolff-Parkinson-White syndrome in terms of the duration of fluoroscopy exposure to the patient and the operator and the effect of accessory-pathway location and operator experience on the success rate. DESIGN: Retrospective review. SETTING: Tertiary care university hospital. PATIENTS: Two hundred consecutive patients with Wolff-Parkinson-White syndrome who underwent radiofrequency catheter ablation between September 1990 and June 1992. INTERVENTIONS: Electrophysiologic study and radiofrequency catheter ablation. MAIN OUTCOME MEASURES: Success rate, duration of fluoroscopy, complications and long-term follow-up. RESULTS: Of the 224 accessory pathways in the 200 patients 135 were left free wall, 47 posteroseptal, 32 right free wall and 10 anteroseptal. The overall success rate increased from 53% in the first 3 months of the study period to 96% in the last 3 months. The success rate depended on the location of the accessory pathway. The duration of fluoroscopic exposure decreased from 50 (standard deviation [SD] 21) minutes in the first 3 months to 40 (SD 15) minutes in the last 3 months (p < 0.05). Complications occurred in 3.5% of the patients; they included hemopericardium, cerebral embolism, perforation of the right atrial wall, air embolism in a coronary artery and hematoma at the arterial perforation site. None of the complications resulted in death. CONCLUSIONS: With experience, radiofrequency catheter ablation of accessory pathways can have an overall success rate of more than 95% and a complication rate of less than 4%. Such rates make this procedure suitable for first-line therapy for patients with Wolff-Parkinson-White syndrome. Images Fig. 1 PMID:8087753

  15. Radiofrequency catheter ablation of Type 1 atrial flutter using a large-tip electrode catheter and high-power radiofrequency energy generator.

    PubMed

    Feld, Gregory K

    2004-11-01

    Recent studies have demonstrated a high degree of efficacy of 8 mm electrode-tipped or saline-irrigated-tip catheters for ablation of atrial flutter (AFL). These catheters have a theoretical advantage as they produce a large ablation lesion. However, large-tip ablation catheters have a larger surface area and require a higher power radiofrequency (RF) generator with up to 100 W capacity to produce adequate ablation temperatures (50-60 degrees C). The potential advantages of a large-tip ablation catheter and high-power RF generator include the need for fewer energy applications, shorter procedure and fluoroscopy times, and greater efficacy. Therefore, the safety and efficacy of AFL ablation using 8 or 10 mm electrode catheters and a 100-W RF generator was studied using the Boston Scientific, Inc., EPT-1000 XP cardiac ablation system. There were 169 patients, aged 61 +/- 12 years involved. Acute end points were bidirectional isthmus block and no inducible AFL. Following ablation, patients were seen at 1, 3 and 6 months, with event monitoring performed weekly and for any symptoms. Three quality of life surveys were completed during follow-up. Acute success was achieved in 158 patients (93%), with 12 +/- 11 RF energy applications. The efficacy of 8 and 10 mm electrodes did not differ significantly. The number of RF energy applications (10 +/- 8 vs. 14 +/- 8) and ablation time (0.5 +/- 0.4 vs. 0.8 +/- 0.6 h) were less with 10 mm compared with 8 mm electrodes (p < 0.01). Of 158 patients with acute success, 42 were not evaluated at 6 months due to study exclusions. Of the 116 patients evaluated at 6 months, 112 (97%) had no AFL recurrence. Of those without AFL recurrence at 6 months, 95 and 93% were free of symptoms at 12 and 24 months, respectively. Ablation of AFL improved quality of life scores (p < 0.05) and reduced anti-arrhythmic and rate control drug use (p < 0.05). Complications occurred in six out of 169 patients (3.6%) but there were no deaths. It was concluded

  16. Fiber-optic catheter-based polarization-sensitive OCT for radio-frequency ablation monitoring

    PubMed Central

    Fu, Xiaoyong; Wang, Zhao; Wang, Hui; Wang, Yves T; Jenkins, Michael W; Rollins, Andrew M

    2015-01-01

    An all-fiber optic catheter-based polarization-sensitive optical coherence tomography system is demonstrated. A novel multiplexing method was used to illuminate the sample, splitting the light from a 58.5kHz Fourier-domain mode-locked laser such that two different polarization states, alternated in time, are generated by two semiconductor optical amplifiers. A 2.3mm forward-view cone-scanning catheter probe was designed, fabricated, and used to acquire sample scattering intensity and phase retardation images. The system was first verified with a quarter-wave plate and then by obtaining intensity and phase retardation images of high-birefringence plastic, human skin in vivo, and untreated and thermally ablated porcine myocardium ex vivo. The system can potentially in vivo image of the cardiac wall to aid radio-frequency ablation therapy for cardiac arrhythmias. PMID:25166075

  17. Fiber-optic catheter-based polarization-sensitive OCT for radio-frequency ablation monitoring.

    PubMed

    Fu, Xiaoyong; Wang, Zhao; Wang, Hui; Wang, Yves T; Jenkins, Michael W; Rollins, Andrew M

    2014-09-01

    An all-fiber optic catheter-based polarization-sensitive optical coherence tomography system is demonstrated. A novel multiplexing method was used to illuminate the sample, splitting the light from a 58.5 kHz Fourier-domain mode-locked laser such that two different polarization states, alternated in time, are generated by two semiconductor optical amplifiers. A 2.3 mm forward-view cone-scanning catheter probe was designed, fabricated, and used to acquire sample scattering intensity and phase retardation images. The system was first verified with a quarter-wave plate and then by obtaining intensity and phase retardation images of high-birefringence plastic, human skin in vivo, and untreated and thermally ablated porcine myocardium ex vivo. The system can potentially in vivo image of the cardiac wall to aid radio-frequency ablation therapy for cardiac arrhythmias. PMID:25166075

  18. Comparison between retrograde and transeptal approach in radiofrequency catheter ablation of left accessory pathways.

    PubMed

    Hashem, S; Choudhury, A K; Paul, G K; Rahman, M Z

    2015-01-01

    To study a series of patients submitted to radiofrequency catheter ablation (RFA) of left accessory pathways (AP) using the transeptal approach (TSA) as compared to the conventional retrograde arterial approach (RAA). Sixty consecutive patients (44 male; mean age of 35.60±11.63 years) with 60 left APs (39 overt and 21 concealed) underwent catheter ablation using the TS method (30 patients) and the RAA method (30 patients) in an alternate fashion. The analysis was performed according to the intention-to-treat principle. The transeptal puncture was successfully performed in 29 patients (96%). This access allowed primary success in the ablation in all the patients without any complication. When we compared this approach with the RAA there was no difference as regards the primary success (p=0.103), fluoroscopy time (p=0.565) and total time (p=0.1917). Three patients in the RAA group presented a vascular complication. The TSA allowed shorter ablation times (p=0.006) and smaller number of radiofrequency applications (p=0.042) as compared to the conventional RAA. The patients who had unsuccessful ablation in the first session in each approach underwent with the opposite technique (cross-over), with a final ablation success rate of 100%.The TS and RA approaches showed similar efficacy and safety for the ablation of left accessory pathways. The TSA allowed shorter ablation times and smaller number of radiofrequency applications. When the techniques were used in a complementary fashion, they increased the final efficacy of the ablation. PMID:25725674

  19. Radiofrequency catheter ablation of Mahaim tachycardia by targeting Mahaim potentials at the tricuspid annulus.

    PubMed Central

    Heald, S. C.; Davies, D. W.; Ward, D. E.; Garratt, C. J.; Rowland, E.

    1995-01-01

    BACKGROUND--Reentrant tachycardias associated with Mahaim pathways are rare but potentially troublesome. Various electrophysiological substrates have been postulated and catheter ablation at several sites has been described. OBJECTIVE--To assess the efficacy and feasibility of targeting discrete Mahaim potentials recorded on the tricuspid annulus for the delivery of radiofrequency energy in the treatment of Mahaim tachycardia. PATIENTS--21 patients out of a consecutive series of 579 patients referred to one of three tertiary centres for catheter ablation of accessory pathways causing tachycardia. All had symptoms and presented with tachycardia of left bundle branch block configuration or had this induced at electrophysiological study. In all cases, the tachycardia was antidromic with anterograde conduction over a Mahaim pathway. RESULTS--6 patients had additional tachycardia substrates (4 had accessory atrioventricular connections and 2 had dual atrioventricular nodal pathways and atrioventricular nodal reentry). After ablation of the additional pathways, Mahaim potentials were identified in 16 (76%) associated with early activation of the distal right bundle branch and radiofrequency energy at this site on the tricuspid annulus abolished Mahaim conduction in all 16 cases. In 2 patients there was early ventricular activation at the annulus without a Mahaim potential but radiofrequency energy abolished pre-excitation. In the remaining patients no potential could be found (1 patient), no tachycardia could be induced after ablation of an additional pathway (1 patient), or no Mahaim conduction was evident during the study (1 patient). During follow up (1-29 months (median 9 months)) all but 1 patient remained symptom free without medication. CONCLUSIONS--Additional accessory pathways seem to be common in patients with Mahaim tachycardias. The identification of Mahaim potentials at the tricuspid annulus confirms that most of these pathways are in the right free wall and

  20. Clinical utility of the Covidien Closure Fast™ Endovenous Radiofrequency Ablation Catheter

    PubMed Central

    Braithwaite, Simon A; Braithwaite, Bruce D

    2014-01-01

    The Closure Fast™ Endovenous Radiofrequency Ablation Catheter is the latest version of a minimally invasive system for the treatment of patients with superficial venous disease. The Closure Fast™ catheter heats the vein wall to 120°C, causing denaturation of the collagen of the vein wall and contraction of the vessel such that no blood can flow through it. Nearly one million systems have been sold since the product was launched. Many, if not all, patients can be treated under local anesthesia with the Closure Fast™ catheter. Duplex ultrasound reports occlusion rates for the treated vein of 94%–98% at 1 year and 85%–93% at 3 years. The system produces average postoperative pain scores of less than 2 out of 10 on a visual analog score. In the first postoperative week, 76% of patients do not require analgesia. Some 45% of patients return to normal activity on the first postoperative day. Serious complications appear to be rare following the Closure Fast™ procedure. Transient paresthesia occurs in 0.2% of cases, thrombophlebitis in 1%–10%, and thromboembolic events in up to 1.4%, mainly heat-induced thrombosis. Closure Fast™ adds significant costs to treating superficial venous disease but studies have shown it to be cost-effective when used in an office setting. PMID:24940086

  1. Prevention of immediate recurrence of atrial fibrillation with low-dose landiolol after radiofrequency catheter ablation

    PubMed Central

    Ishigaki, Daisuke; Arimoto, Takanori; Iwayama, Tadateru; Hashimoto, Naoaki; Kutsuzawa, Daisuke; Kumagai, Yu; Nishiyama, Satoshi; Takahashi, Hiroki; Shishido, Tetsuro; Miyamoto, Takuya; Watanabe, Tetsu; Kubota, Isao

    2015-01-01

    Background Immediate recurrence of atrial fibrillation (AF) after radiofrequency (RF) catheter ablation is commonly observed within 3 d after the procedure. The mechanism and pharmacological management of immediate AF recurrence remain unclear. Methods A total of 50 consecutive patients with paroxysmal AF were randomized to receive either low-dose landiolol (landiolol group) or a placebo (placebo group). In the landiolol group, intravenous landiolol (0.5 μg kg−1 min−1) was administered for 3 d after AF ablation. Results No serious adverse event associated with RF catheter ablation or landiolol administration was observed. The prevalence of immediate AF recurrence (≤3 d after RF catheter ablation) was significantly lower in the landiolol group than in the placebo group (16% vs. 48%, p=0.015). Although the postprocedural change in heart rate was significantly lower in the landiolol group compared to that in the placebo group, the changes in blood pressure and body temperature were not different between the two groups. Multiple logistic regression analysis revealed that landiolol treatment was the only independent predictor of immediate AF recurrence after ablation (odds ratio: 0.180; 95% confidence interval: 0.044–0.729; p=0.016). Conclusions Prophylactic administration of low-dose landiolol after AF ablation may be effective and safe for preventing immediate AF recurrence within 3 d after AF ablation. PMID:26550083

  2. [Radiofrequency catheter ablation of two accessory pathways in patients with WPW Syndrome].

    PubMed

    Kalarus, Z; Kowalski, O; Prokopczuk, J; Chodór, P; Sredniawa, B; Pasyk, S

    1998-12-01

    In 10-30% patients with WPW syndrome more than one accessory pathway in electrophysiology study is observed. These patients make a group of higher atrial fibrillation and coming next ventricle fibrillation risk. We present the 39 years old patient with symptomatic WPW syndrome, without preexcitation signs in ECG at rest. In medical history--palpitations was observed from childhood with one episode of atrial fibrillation with high ventricle response required cardioversion. Electrophysiology study: without preexcitation signs at rest, two ortodromic AV reentrant tachycardias were induced--200 and 166/min. Two accessory pathways were diagnosed, left lateral and left midseptal. Radiofrequency catheter ablation of both accessory pathways was made during tachycardia, first lateral, next septal. In six month follow-up the patient was asymptomatic. PMID:10405568

  3. Novel use of epidural catheter: Air injection for neuroprotection during radiofrequency ablation of spinal osteoid osteoma.

    PubMed

    Doctor, J R; Solanki, S L; Patil, V P; Divatia, J V

    2016-01-01

    Osteoid osteoma (OO) is a benign bone tumor, with a male-female ratio of approximately 2:1 and mainly affecting long bones. Ten percent of the lesions occur in the spine, mostly within the posterior elements. Treatment options for OO include surgical excision and percutaneous imaging-guided radiofrequency ablation (RFA). Lesions within the spine have an inherent risk of thermal damage to the vital structure because of proximity to the neural elements. We report a novel use of the epidural catheter for air injection for the neuroprotection of nerves close to the OO of the spine. A 12-year-old and 30 kg male child with an OO of the L3 vertebra was taken up for RFA. His preoperative examinations were within normal limits. The OO was very close to the L3 nerve root. Under general anesthesia, lumbar epidural catheter was placed in the L3-L4 space under imaging guidance. Ten ml of aliquots of air was injected under imaging guidance to avoid injury to the neural structures due to RFA. The air created a gap between neural elements and the tumor and served as an insulating material thereby protecting the neural elements from damage due to the RFA. Postoperatively, the patient did not develop any neurological deficit. PMID:27375396

  4. Novel use of epidural catheter: Air injection for neuroprotection during radiofrequency ablation of spinal osteoid osteoma

    PubMed Central

    Doctor, JR; Solanki, SL; Patil, VP; Divatia, JV

    2016-01-01

    Osteoid osteoma (OO) is a benign bone tumor, with a male-female ratio of approximately 2:1 and mainly affecting long bones. Ten percent of the lesions occur in the spine, mostly within the posterior elements. Treatment options for OO include surgical excision and percutaneous imaging-guided radiofrequency ablation (RFA). Lesions within the spine have an inherent risk of thermal damage to the vital structure because of proximity to the neural elements. We report a novel use of the epidural catheter for air injection for the neuroprotection of nerves close to the OO of the spine. A 12-year-old and 30 kg male child with an OO of the L3 vertebra was taken up for RFA. His preoperative examinations were within normal limits. The OO was very close to the L3 nerve root. Under general anesthesia, lumbar epidural catheter was placed in the L3-L4 space under imaging guidance. Ten ml of aliquots of air was injected under imaging guidance to avoid injury to the neural structures due to RFA. The air created a gap between neural elements and the tumor and served as an insulating material thereby protecting the neural elements from damage due to the RFA. Postoperatively, the patient did not develop any neurological deficit. PMID:27375396

  5. Radiation exposure to operator and patients during cardiac electrophysiology study, radiofrequency catheter ablation and cardiac device implantation procedures

    NASA Astrophysics Data System (ADS)

    Lee, C. H.; Cho, J. H.; Park, S. J.; Kim, J. S.; On, Y. K.; Huh, J.

    2015-10-01

    The purpose of this study was to measure the radiation exposure to operator and patient during cardiac electrophysiology study, radiofrequency catheter ablation and cardiac device implantation procedures and to calculate the allowable number of cases per year. We carried out 9 electrophysiology studies, 40 radiofrequency catheter ablation and 11 cardiac device implantation procedures. To measure occupational radiation dose and dose-area product (DAP), 13 photoluminescence glass dosimeters were placed at eyes (inside and outside lead glass), thyroids (inside and outside thyroid collar), chest (inside and outside lead apron), wrists, genital of the operator (inside lead apron), and 6 of photoluminescence glass dosimeters were placed at eyes, thyroids, chest and genital of the patient. Exposure time and DAP values were 11.7 ± 11.8 min and 23.2 ± 26.2 Gy cm2 for electrophysiology study; 36.5 ± 42.1 min and 822.4 ± 125.5 Gy cm2 for radiofrequency catheter ablation; 16.2 ± 9.3 min and 27.8 ± 16.5 Gy cm2 for cardiac device implantation procedure, prospectively. 4591 electrophysiology studies can be conducted within the occupational exposure limit for the eyes (150 mSv), and 658-electrophysiology studies with radiofrequency catheter ablation can be carried out within the occupational exposure limit for the hands (500 mSv). 1654 cardiac device implantation procedure can be conducted within the occupational exposure limit for the eyes (150 mSv). The amounts of the operator and patient's radiation exposure were comparatively small. So, electrophysiology study, radio frequency catheter ablation and cardiac device implantation procedures are safe when performed with modern equipment and optimized protective radiation protect equipment.

  6. Catheter-based radiofrequency renal-nerve ablation in patients with resistant hypertension.

    PubMed

    Azizi, M; Steichen, O; Frank, M; Bobrie, G; Plouin, P-F; Sapoval, M

    2012-03-01

    This review aims to describe the role and the results of catheter-based renal nerve ablation for the treatment of resistant hypertension. Despite the availability of multiple classes of orally active antihypertensive treatments, resistant hypertension remains an important public health issue in 2012 due to its prevalence and association with target-organ damage and poor prognosis. The failure of purely pharmacological approaches to treat resistant hypertension has stimulated interest in invasive device-based treatments based on old concepts. In the absence of orally active antihypertensive agents, patients with severe and complicated hypertension were widely treated by surgical denervation of the kidney until the 1960s, but this approach was associated with a high incidence of severe adverse events and a high mortality rate. A new catheter system using radiofrequency energy has been developed, allowing an endovascular approach to renal denervation and providing patients with resistant hypertension with a new therapeutic option that is less invasive than surgery and can be performed rapidly under local anaesthesia. To date, this technique has been evaluated only in open-label trials including small numbers of highly selected resistant hypertensive patients with suitable renal artery anatomy. The available evidence suggests a favourable blood pressure-lowering effect in the short term (6 months) and a low incidence of immediate local and endovascular complications. This follow-up period is, however, too short for the detection of rare or late-onset adverse events. For the time being, the benefit/risk ratio of this technique remains to be evaluated, precluding its uncontrolled and widespread use in routine practice. PMID:22237510

  7. [Long-term results of low-speed irrigated radiofrequency catheter ablation of atrial flutter].

    PubMed

    Ardashev, V N; Ardashev, A V; Novichkov, S A; Konev, A V; Voloshko, S V; Shavarov, A A

    2007-01-01

    The authors studied long-term results of low-speed (10 ml/min) irrigated radiofrequency catheter ablation (RFA) of the lower isthmus (LI) in patients with typical atrial flutter (AF). This treatment was based upon combined use of local and indirect criteria of the block of isthmus conduction. The influence of RFA LI on quality of life (QL), echocardiographic parameters and cardiac rhythm variability (CRV) was studied. Low-speed irrigated RFA LI, based upon combined use of local and indirect criteria for verification of complete bidirectional blockade in this area, is an effective and safe method of treatment of patients with different variants of clinical course of typical AF which makes it possible to significantly improve QL characteristics and central hemodynamic parameters, and normalize CVR parameters as well. Self-organization of chaos, which realizes according to RR interval time rows, in patients with typical AF after RFA LI may be considered an additional criterion of the effectiveness of this operative intervention and a prognostic sign that predicts maintenance of sinus rhythm in this category of patients. PMID:17601035

  8. Value of Implantable Loop Recorders in Monitoring Efficacy of Radiofrequency Catheter Ablation in Atrial Fibrillation

    PubMed Central

    Yang, Ping; Pu, Lijin; Yang, Liuqing; Li, Fang; Luo, Zhiling; Guo, Tao; Hua, Baotong; Li, Shumin

    2016-01-01

    Background The aim of this study was to evaluate the value of the implantable loop recorder (ILR) in diagnosing atrial fibrillation (AF) and assessing the postoperative efficacy of radiofrequency catheter ablation (RFCA). Material/Methods A total of 32 patients who successfully underwent RFCA were selected. These patients discontinued antiarrhythmic medication with no AF recurrence for more than 3 months after RFCA, and underwent ILR placement by a conventional method. The clinical manifestations and information on arrhythmias recorded by the ILR were followed up to assess the efficacy of AF RFCA. Results The mean follow-up period was 24.7±12.5 months. Of 32 patients with ILR information, 27 had successful RFCA and 5 had recurrent AF. The follow-up results obtained by traditional methods showed 29 patients with successful RFCA and 3 with recurrent AF (P<0.05). Among the 18 patients with clinical symptoms, 13 had recorded cardiac arrhythmic events (72.2%) and 5 showed sinus rhythm (27.8%). The ILRs recorded 18 patients with arrhythmic events (56.3%), including 12 cases of atrial arrhythmias, among whom 5 recurred at 9, 12, 16, 17, and 32 months after AF RFCA; there were also 2 patients with ventricular tachycardia (VT) and 4 with bradycardia. Conclusions The value of ILR in assessing the efficacy of AF RFCA was superior to that of traditional methods. ILR can promptly detect asymptomatic AF, and can monitor electrocardiogram features after RFCA, thus providing objective evidence of efficacy. PMID:27518153

  9. Pulmonary vein stenosis complicating radiofrequency catheter ablation for atrial fibrillation: A literature review.

    PubMed

    Edriss, Hawa; Denega, Tatiana; Test, Victor; Nugent, Kenneth

    2016-08-01

    Radiofrequency catheter ablation has become a widely used intervention in the treatment of atrial fibrillation. Pulmonary vein stenosis (PVS) is one of the most serious complications associated with this procedure; the degree of stenosis ranges from mild (<50%) to complete venous occlusion. The natural history of PVS and the risk of progression of existing PVS are uncertain. Symptomatic and/or severe PVS is a serious medical problem and can be easily misdiagnosed since it is an uncommon and relatively new medical problem, often has low clinical suspicion among clinicians, and has a non-specific presentation that mimics other more common respiratory or cardiac diseases. The estimated incidence varies in literature reports from 0% to 42% of ablation procedures, depending on technical aspects of the procedure and operator skill. Most patients with significant PVS remain asymptomatic or have few symptoms. Symptomatic patients usually present with dyspnea, chest pain, or hemoptysis and are usually treated with balloon angioplasty and/or stent placement. Little is known about the long term effect of PV stenosis/occlusion on the pulmonary circulation and the development of pulmonary hypertension. Evolving technology may reduce the frequency of this complication, but long term studies are needed to understand the effect of therapeutic atrial injury and adverse outcomes. This review summarizes the current literature and outlines an approach to the evaluation and management of these patients. PMID:27492534

  10. New-onset ventricular arrhythmias post radiofrequency catheter ablation for atrial fibrillation.

    PubMed

    Wu, Lingmin; Lu, Yanlai; Yao, Yan; Zheng, Lihui; Chen, Gang; Ding, Ligang; Hou, Bingbo; Qiao, Yu; Sun, Wei; Zhang, Shu

    2016-09-01

    As a new complication, new-onset ventricular arrhythmias (VAs) post atrial fibrillation (AF) ablation have not been well defined. This prospective study aimed to describe the details of new-onset VAs post AF ablation in a large study cohort.One thousand fifty-three consecutive patients who underwent the first radiofrequency catheter ablation for AF were enrolled. All patients had no evidence of pre-ablation VAs. New-onset VAs were defined as new-onset ventricular tachycardia (VT) or premature ventricular contractions (PVC) ≥1000/24 h within 1 month post ablation.There were 46 patients (4.4%) who had 62 different new-onset VAs, among whom 42 were PVC alone, and 4 were PVC coexisting with nonsustained VT. Multivariate analysis showed that increased serum leukocyte counts ≥50% post ablation were independently associated with new-onset VAs (OR: 1.9; 95% CI: 1.0-3.5; P = 0.043). The median number of PVC was 3161 (1001-27,407) times/24 h. Outflow tract VAs were recorded in 35 (76.1%) patients. No significant differences were found in origin of VAs (P = 0.187). VAs disappeared without any treatment in 6 patients (13.0%). No VAs-related adverse cardiac event occurred.The study revealed a noticeable prevalence but relatively benign prognosis of new-onset VAs post AF ablation. Increased serum leukocyte counts ≥50% post ablation appeared to be associated with new-onset VAs, implying that inflammatory response caused by ablation might be the mechanism. PMID:27603357

  11. Non-fluoroscopic navigation systems for radiofrequency catheter ablation for supraventricular tachycardia reduce ionising radiation exposure

    PubMed Central

    See, Jason; Amora, Jonah L; Lee, Sheldon; Lim, Paul; Teo, Wee Siong; Tan, Boon Yew; Ho, Kah Leng; Lee, Chee Wan; Ching, Chi Keong

    2016-01-01

    INTRODUCTION The use of non-fluoroscopic systems (NFS) to guide radiofrequency catheter ablation (RFCA) for the treatment of supraventricular tachycardia (SVT) is associated with lower radiation exposure. This study aimed to determine if NFS reduces fluoroscopy time, radiation dose and procedure time. METHODS We prospectively enrolled patients undergoing RFCA for SVT. NFS included EnSite™ NavX™ or CARTO® mapping. We compared procedure and fluoroscopy times, and radiation exposure between NFS and conventional fluoroscopy (CF) cohorts. Procedural success, complications and one-year success rates were reported. RESULTS A total of 200 patients over 27 months were included and RFCA was guided by NFS for 79 patients; those with atrioventricular nodal reentrant tachycardia (AVNRT), left-sided atrioventricular reentrant tachycardia (AVRT) and right-sided AVRT were included (n = 101, 63 and 36, respectively). Fluoroscopy times were significantly lower with NFS than with CF (10.8 ± 11.1 minutes vs. 32.0 ± 27.5 minutes; p < 0.001). The mean fluoroscopic dose area product was also significantly reduced with NFS (NSF: 5,382 ± 5,768 mGy*cm2 vs. CF: 21,070 ± 23,311 mGy*cm2; p < 0.001); for all SVT subtypes. There was no significant reduction in procedure time, except for left-sided AVRT ablation (NFS: 79.2 minutes vs. CF: 116.4 minutes; p = 0.001). Procedural success rates were comparable (NFS: 97.5% vs. CF: 98.3%) and at one-year follow-up, there was no significant difference in the recurrence rates (NFS: 5.2% vs. CF: 4.2%). No clinically significant complications were observed in both groups. CONCLUSION The use of NFS for RFCA for SVT is safe, with significantly reduced radiation dose and fluoroscopy time. PMID:26805664

  12. Near-infrared spectroscopy integrated catheter for characterization of myocardial tissues: preliminary demonstrations to radiofrequency ablation therapy for atrial fibrillation

    PubMed Central

    Singh-Moon, Rajinder P.; Marboe, Charles C.; Hendon, Christine P.

    2015-01-01

    Effects of radiofrequency ablation (RFA) treatment of atrial fibrillation can be limited by the ability to characterize the tissue in contact. Parameters obtained by conventional catheters, such as impedance and temperature can be insufficient in providing physiological information pertaining to effective treatment. In this report, we present a near-infrared spectroscopy (NIRS)-integrated catheter capable of extracting tissue optical properties. Validation experiments were first performed in tissue phantoms with known optical properties. We then apply the technique for characterization of myocardial tissues in swine and human hearts, ex vivo. Additionally, we demonstrate the recovery of critical parameters relevant to RFA therapy including contact verification, and lesion transmurality. These findings support the application of NIRS for improved guidance in RFA therapeutic interventions. PMID:26203376

  13. Near-infrared spectroscopy integrated catheter for characterization of myocardial tissues: preliminary demonstrations to radiofrequency ablation therapy for atrial fibrillation.

    PubMed

    Singh-Moon, Rajinder P; Marboe, Charles C; Hendon, Christine P

    2015-07-01

    Effects of radiofrequency ablation (RFA) treatment of atrial fibrillation can be limited by the ability to characterize the tissue in contact. Parameters obtained by conventional catheters, such as impedance and temperature can be insufficient in providing physiological information pertaining to effective treatment. In this report, we present a near-infrared spectroscopy (NIRS)-integrated catheter capable of extracting tissue optical properties. Validation experiments were first performed in tissue phantoms with known optical properties. We then apply the technique for characterization of myocardial tissues in swine and human hearts, ex vivo. Additionally, we demonstrate the recovery of critical parameters relevant to RFA therapy including contact verification, and lesion transmurality. These findings support the application of NIRS for improved guidance in RFA therapeutic interventions. PMID:26203376

  14. Atrial rhythm influences catheter tissue contact during radiofrequency catheter ablation of atrial fibrillation: comparison of contact force between sinus rhythm and atrial fibrillation.

    PubMed

    Matsuda, Hisao; Parwani, Abdul Shokor; Attanasio, Philipp; Huemer, Martin; Wutzler, Alexander; Blaschke, Florian; Haverkamp, Wilhelm; Boldt, Leif-Hendrik

    2016-09-01

    Catheter tissue contact force (CF) is an important factor for durable lesion formation during radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). Since CF varies in the beating heart, atrial rhythm during RFCA may influence CF. A high-density map and RFCA points were obtained in 25 patients undergoing RFCA of AF using a CF-sensing catheter (Tacticath, St. Jude Medical). The operators were blinded to the CF information. Contact type was classified into three categories: constant, variable, and intermittent contact. Average CF and contact type were analyzed according to atrial rhythm (SR vs. AF) and anatomical location. A total of 1364 points (891 points during SR and 473 points during AF) were analyzed. Average CFs showed no significant difference between SR (17.2 ± 11.3 g) and AF (17.2 ± 13.3 g; p = 0.99). The distribution of points with an average CF of ≥20 and <10 g also showed no significant difference. However, the distribution of excessive CF (CF ≥40 g) was significantly higher during AF (7.4 %) in comparison with SR (4.2 %; p < 0.05). At the anterior area of the right inferior pulmonary vein (RIPV), the average CF during AF was significantly higher than during SR (p < 0.05). Constant contact was significantly higher during AF (32.2 %) when compared to SR (9.9 %; p < 0.01). Although the average CF was not different between atrial rhythms, constant contact was more often achievable during AF than it was during SR. However, excessive CF also seems to occur more frequently during AF especially at the anterior part of RIPV. PMID:26498938

  15. Radiofrequency ablation with a vibrating catheter: A new method for electrode cooling.

    PubMed

    Yu, Kaihong; Yamashita, Tetsui; Shingyochi, Shigeaki; Matsumoto, Kazuo; Ohta, Makoto

    2016-05-01

    A new electrode cooling system using a vibrating catheter is described for conditions of low blood flow when saline irrigation cannot be used. Vibrations of the catheter are hypothesized to disturb blood flow around the electrode, leading to increased convective cooling of the electrode. The aim of this study is to confirm the cooling effect of vibration and investigate the associated mechanisms. As methods, an in vitro system with polyvinyl alcohol-hydrogel (PVA-H) as ablated tissue and saline flow in an open channel was used to measure changes in electrode and tissue temperatures under vibration of 0-63Hz and flow velocity of 0-0.1m/s. Flow around the catheter was observed using particle image velocimetry (PIV). Results show that under conditions of no flow, electrode temperatures decreased with increasing vibration frequency, and in the absence of vibrations, electrode temperatures decreased with increasing flow velocity. In the presence of vibrations, electrode temperatures decreased under conditions of low flow velocity, but not under those of high flow velocity. PIV analyses showed disturbed flow around the vibrating catheter, and flow velocity around the catheter increased with higher-frequency vibrations. In conclusion, catheter vibration facilitated electrode cooling by increasing flow around the catheter, and cooling was proportional to vibration frequency. PMID:27013053

  16. Optoacoustic monitoring of real-time lesion formation during radiofrequency catheter ablation

    NASA Astrophysics Data System (ADS)

    Pang, Genny A.; Bay, Erwin; Deán-Ben, Xosé L.; Razansky, Daniel

    2015-03-01

    Current radiofrequency cardiac ablation procedures lack real-time lesion monitoring guidance, limiting the reliability and efficacy of the treatment. The objective of this work is to demonstrate that optoacoustic imaging can be applied to develop a diagnostic technique applicable to radiofrequency ablation for cardiac arrhythmia treatment with the capabilities of real-time monitoring of ablated lesion size and geometry. We demonstrate an optoacoustic imaging method using a 256-detector optoacoustic imaging probe and pulsed-laser illumination in the infrared wavelength range that is applied during radiofrequency ablation in excised porcine myocardial tissue samples. This technique results in images with high contrast between the lesion volume and unablated tissue, and is also capable of capturing time-resolved image sequences that provide information on the lesion development process. The size and geometry of the imaged lesion were shown to be in excellent agreement with the histological examinations. This study demonstrates the first deep-lesion real-time monitoring for radiofrequency ablation generated lesions, and the technique presented here has the potential for providing critical feedback that can significantly impact the outcome of clinical radiofrequency ablation procedures.

  17. Radiofrequency catheter ablation of accessory atrioventricular pathways in children and young adults.

    PubMed Central

    Sreeram, N; Smeets, J L; Pulles-Heintzberger, C F; Wellens, H J

    1993-01-01

    OBJECTIVE--To assess the efficacy of radiofrequency ablation for reentrant tachyarrhythmias in children and young adults. SETTING--A tertiary cardiac referral centre. PATIENTS AND INTERVENTIONS--Over a 16 month period 22 patients aged less than 20 years (median age 16.5 years) underwent 26 radiofrequency ablation procedures for atrioventricular reentry tachycardia through an accessory pathway. The results of radiofrequency ablation were compared with those in a group of 16 patients (median age 14 years) who had had surgical ablation for atrioventricular reentry tachycardia over a preceding six year period. RESULTS--Ablation of an accessory atrioventricular pathway was accomplished for 18 (76%) of 25 pathways in 16 (73%) of 22 patients. There were no procedure-related complications. Surgery was eventually curative in 15/16 patients (94%). However, three patients required a second open heart surgical procedure because tachyarrhythmia recurred. There were no surgical deaths. Failures for radiofrequency ablation were related to accessory pathway location, and were greater for right free wall and posteroseptal pathways (success rate of 50% and 57% respectively). Recurrence after surgery was also associated with pathways in these locations. CONCLUSIONS--Transcatheter radiofrequency current ablation was safe and achieved a cure with less patient morbidity and improved cost efficiency. It is an attractive alternative to long-term drug therapy or surgery in older children and adolescents. A higher success rate may be expected with increased experience. PMID:8038027

  18. PATH OPTIMIZATION AND CONTROL OF A SHAPE MEMORY ALLOY ACTUATED CATHETER FOR ENDOCARDIAL RADIOFREQUENCY ABLATION

    PubMed Central

    Wiest, Jennifer H.; Buckner, Gregory D.

    2014-01-01

    This paper introduces a real-time path optimization and control strategy for shape memory alloy (SMA) actuated cardiac ablation catheters, potentially enabling the creation of more precise lesions with reduced procedure times and improved patient outcomes. Catheter tip locations and orientations are optimized using parallel genetic algorithms to produce continuous ablation paths with near normal tissue contact through physician-specified points. A nonlinear multivariable control strategy is presented to compensate for SMA hysteresis, bandwidth limitations, and coupling between system inputs. Simulated and experimental results demonstrate efficient generation of ablation paths and optimal reference trajectories. Closed-loop control of the SMA-actuated catheter along optimized ablation paths is validated experimentally. PMID:25684857

  19. Radiofrequency catheter ablation for dyssynchrony-induced dilated cardiomyopathy in an infant.

    PubMed

    Kwon, Elena N; Carter, Kerri A; Kanter, Ronald J

    2014-01-01

    The relationship between accessory pathway-mediated ventricular preexcitation and left ventricular dyssynchrony-induced dysfunction has been described in patients with Wolff-Parkinson-White (WPW) syndrome in the absence of sustained supraventricular tachycardia (SVT). Supraventricular tachycardia in infants is usually successfully suppressed with antiarrhythmic medications, but catheter ablation has ultimately been required as definitive treatment in medically resistant cases. Catheter ablation has not been described in young infants for dyssynchrony-related dilated cardiomyopathy in the absence of SVT. We describe a case of an infant with WPW who did not have sustained supraventricular tachycardia, but who developed rapid progression of ventricular dysfunction after birth. Preexcitation could not be medically suppressed but was successfully ablated. This was followed by complete resolution of ventricular dysfunction within 2 months. PMID:23902593

  20. Prevention and Treatment of Lower Limb Deep Vein Thrombosis after Radiofrequency Catheter Ablation: Results of a Prospective active controlled Study

    PubMed Central

    Li, Lan; Zhang, Bao-jian; Zhang, Bao-ku; Ma, Jun; Liu, Xu-zheng; Jiang, Shu-bin

    2016-01-01

    We conducted a prospective, single-center, active controlled study from July 2013 to January 2015, in Chinese patients with rapid ventricular arrhythmia who had received radiofrequency catheter ablation (RFCA) treatment to determine formation of lower extremity deep vein thrombosis (LDVT) post RFCA procedure, and evaluated the effect of rivaroxaban on LDVT. Patients with asymptomatic pulmonary thromboembolism who had not received any other anticoagulant and had received no more than 36 hours of treatment with unfractionated heparin were included. Post RFCA procedure, patients received either rivaroxaban (10 mg/d for 14 days beginning 2–3 hours post-operation; n = 86) or aspirin (100 mg/d for 3 months beginning 2–3 hours post-operation; n = 90). The primary outcome was a composite of LDVT occurrence, change in diameter of femoral veins, and safety outcomes that were analyzed based on major or minor bleeding events. In addition, blood flow velocity was determined. No complete occlusive thrombus or bleeding events were reported with either of the group. The lower incidence rate of non-occluded thrombus in rivaroxaban (5.8%) compared to the aspirin group (16.7%) indicates rivaroxaban may be administered post-RFCA to prevent and treat femoral venous thrombosis in a secure and effective way with a faster inset of action than standard aspirin therapy. PMID:27329582

  1. Radiofrequency Catheter Ablation for Atrial Fibrillation Elicited "Jackhammer Esophagus": A New Complication Due to Vagal Nerve Stimulation?

    PubMed

    Tolone, Salvatore; Savarino, Edoardo; Docimo, Ludovico

    2015-10-01

    Radiofrequency catheter ablation (RFCA) is a potentially curative method for treatment of highly symptomatic and drug-refractory atrial fibrillation (AF). However, this technique can provoke esophageal and nerve lesion, due to thermal injury. To our knowledge, there have been no reported cases of a newly described motor disorder, the Jackhammer esophagus (JE) after RFCA, independently of GERD. We report a case of JE diagnosed by high-resolution manometry (HRM), in whom esophageal symptoms developed 2 weeks after RFCA, in absence of objective evidence of GERD. A 65-year-old male with highly symptomatic, drug-refractory paroxysmal AF was candidate to complete electrical pulmonary vein isolation with RFCA. Prior the procedure, the patient underwent HRM and impedance-pH to rule out GERD or hiatal hernia presence. All HRM parameters, according to Chicago classification, were within normal limits. No significant gastroesophageal reflux was documented at impedance pH monitoring. Patient underwent RFCA with electrical disconnection of pulmonary vein. After two weeks, patient started to complain of dysphagia for solids, with acute chest-pain. The patient repeated HRM and impedance-pH monitoring 8 weeks after RFCA. HRM showed in all liquid swallows the typical spastic hypercontractile contractions consistent with the diagnosis of JE, whereas impedance-pH monitoring resulted again negative for GERD. Esophageal dysmotility can represent a possible complication of RFCA for AF, probably due to a vagal nerve injury, and dysphagia appearance after this procedure must be timely investigated by HRM. PMID:26351090

  2. Incidence and Factors Predicting Skin Burns at the Site of Indifferent Electrode during Radiofrequency Catheter Ablation of Cardiac Arrhythmias

    PubMed Central

    Ibrahim, Hussain; Finta, Bohuslav; Rind, Jubran

    2016-01-01

    Radiofrequency catheter ablation (RFA) has become a mainstay for treatment of cardiac arrhythmias. Skin burns at the site of an indifferent electrode patch have been a rare, serious, and likely an underreported complication of RFA. The purpose of this study was to determine the incidence of skin burns in cardiac RFA procedures performed at one institution. Also, we wanted to determine the factors predicting skin burns after cardiac RFA procedures at the indifferent electrode skin pad site. Methods. A retrospective case control study was performed to compare the characteristics in patients who developed skin burns in a 2-year period. Results. Incidence of significant skin burns after RFA was 0.28% (6/2167). Four of the six patients were female and all were Caucasians. Four controls for every case were age and sex matched. Burn patients had significantly higher BMI, procedure time, and postprocedure pain, relative to control subjects (p < 0.05, one-tailed testing). No one in either group had evidence of dispersive pad malattachment. Conclusions. Our results indicate that burn patients had higher BMI and longer procedure times compared to control subjects. These findings warrant further larger studies on this topic. PMID:27213077

  3. Radiofrequency Catheter Ablation for Atrial Fibrillation Elicited “Jackhammer Esophagus”: A New Complication Due to Vagal Nerve Stimulation?

    PubMed Central

    Tolone, Salvatore; Savarino, Edoardo; Docimo, Ludovico

    2015-01-01

    Radiofrequency catheter ablation (RFCA) is a potentially curative method for treatment of highly symptomatic and drug-refractory atrial fibrillation (AF). However, this technique can provoke esophageal and nerve lesion, due to thermal injury. To our knowledge, there have been no reported cases of a newly described motor disorder, the Jackhammer esophagus (JE) after RFCA, independently of GERD. We report a case of JE diagnosed by high-resolution manometry (HRM), in whom esophageal symptoms developed 2 weeks after RFCA, in absence of objective evidence of GERD. A 65-year-old male with highly symptomatic, drug-refractory paroxysmal AF was candidate to complete electrical pulmonary vein isolation with RFCA. Prior the procedure, the patient underwent HRM and impedance-pH to rule out GERD or hiatal hernia presence. All HRM parameters, according to Chicago classification, were within normal limits. No significant gastroesophageal reflux was documented at impedance pH monitoring. Patient underwent RFCA with electrical disconnection of pulmonary vein. After two weeks, patient started to complain of dysphagia for solids, with acute chest-pain. The patient repeated HRM and impedance-pH monitoring 8 weeks after RFCA. HRM showed in all liquid swallows the typical spastic hypercontractile contractions consistent with the diagnosis of JE, whereas impedance-pH monitoring resulted again negative for GERD. Esophageal dysmotility can represent a possible complication of RFCA for AF, probably due to a vagal nerve injury, and dysphagia appearance after this procedure must be timely investigated by HRM. PMID:26351090

  4. Radiofrequency Catheter Ablation of Accessory Atrioventricular Pathways in Infants and Toddlers ≤ 15 kg.

    PubMed

    Backhoff, David; Klehs, Sophia; Müller, Matthias J; Schneider, Heike; Kriebel, Thomas; Paul, Thomas; Krause, Ulrich

    2016-06-01

    Accessory atrioventricular pathways (AP) are the most common substrate for paroxysmal supraventricular tachycardia in infants and small children. Up-to-date data on AP ablation in infants and small children are limited. The aim of the present study was to gain additional insight into radiofrequency (RF) catheter ablation of AP in infants and toddlers focusing on efficacy and safety in patients with a body weight of ≤ 15 kg. Since 10/2002, RF ablation of AP was performed in 281 children in our institution. Indications, procedural data as well as success and complication rates in children with a body weight ≤ 15 kg (n = 22) were compared with children > 15 kg (n = 259). Prevalence of structural heart anomalies was significantly higher among children ≤ 15 kg (27 vs. 5.7 %; p = 0.001). Procedure duration (median 262 vs. 177 min; p = 0.001) and fluoroscopy time (median 20.6 vs. 14.0 min; p = 0.007) were significantly longer among patients ≤ 15 kg. Procedural success rate did not differ significantly between the two groups (82 vs. 90 %). More RF lesions were required for AP ablation in the smaller patients (median 12 vs. 7; p = 0.019). Major complication rate was significantly higher in children ≤ 15 kg (9 vs. 1.1 %; p = 0.05) with femoral vessel occlusion being the only major adverse event in patients ≤ 15 kg. Catheter ablation of AP in children was effective irrespective of body weight. In children ≤ 15 kg, however, procedures were more challenging and time-consuming. Complication rate and number of RF lesions in smaller children were higher when compared to older children. PMID:26961570

  5. Fibrillation number based on wavelength and critical mass in patients who underwent radiofrequency catheter ablation for atrial fibrillation.

    PubMed

    Hwang, Minki; Park, Junbeum; Lee, Young-Seon; Park, Jae Hyung; Choi, Sung Hwan; Shim, Eun Bo; Pak, Hui-Nam

    2015-02-01

    The heart characteristic length, the inverse of conduction velocity (CV), and the inverse of the refractory period are known to determine vulnerability to cardiac fibrillation (fibrillation number, FibN) in in silico or ex vivo models. The purpose of this study was to validate the accuracy of FibN through in silico atrial modeling and to evaluate its clinical application in patients with atrial fibrillation (AF) who had undergone radiofrequency catheter ablation. We compared the maintenance duration of AF at various FibNAF values using in silico bidomain atrial modeling. Among 60 patients (72% male, 54±13 years old, 82% with paroxysmal AF) who underwent circumferential pulmonary vein isolation (CPVI) for AF rhythm control, we examined the relationship between FibN AF and postprocedural AF inducibility or induction pacing cycle length (iPCL). Clinical FibNAF was calculated using left atrium (LA) dimension (echocardiogram), the inverse of CV, and the inverse of the atrial effective refractory periods measured at proximal and distal coronary sinus. In silico simulation found a positive correlation between AF maintenance duration and FibNAF ( R = 0.90, ). After clinical CPVI, FibNAF ( 0.296±0.038 versus 0.192±0.028, ) was significantly higher in patients with postprocedural AF inducibility ( n = 41) than in those without ( n = 19 ). Among 41 patients with postprocedural AF inducibility, FibNAF ( P = 0.935, ) had excellent correlations with induction pacing cycle length. FibNAF, based on LA mass and wavelength, correlates well with AF maintenance in computational modeling and clinical AF inducibility after CPVI. PMID:25343755

  6. Real-time monitoring of cardiac radio-frequency ablation lesion formation using an optical coherence tomography forward-imaging catheter

    PubMed Central

    Fleming, Christine P.; Wang, Hui; Quan, Kara J.; Rollins, Andrew M.

    2010-01-01

    Radio-frequency ablation (rfa) is the standard of care for the treatment of cardiac arrhythmias; however, there are no direct measures of the successful delivery of ablation lesions. Optical coherence tomography (OCT) imaging has the potential to provide real-time monitoring of cardiac rfa therapy, visualizing lesion formation and assessing tissue contact in the presence of blood. A rfa-compatible forward-imaging conical scanning probe is prototyped to meet this need. The forward-imaging probe provides circular scanning, with a 2-mm scan diameter and 30-μm spot size. During the application of rf energy, dynamics are recorded at 20 frames per second with a 40-kHz A-line rate. Real-time monitoring of cardiac rfa lesion formation and imaging in the presence of blood is demonstrated ex vivo in a swine left ventricle with a forward, flexible, circular scanning OCT catheter. PMID:20614999

  7. The effect of changes in patients’ body position on the back pain intensity and hemodynamic status during and after radiofrequency catheter ablation of cardiac dysrhythmias

    PubMed Central

    Haghshenas, Hajar; Mansoori, Parisa; Najafi, Saeed; Nikoo, Mohamad Hosein; Zare, Najaf; Jonoobi, Mitra

    2013-01-01

    Background: After radiofrequency catheter ablation of arrhythmias, patients have to bed rest for 4-6 h to prevent bleeding and hematoma. However, such a rest may cause back pain in the patients. The aim of this study was to determine the effects of continuous change in body position during and after the radiofrequency ablation on the back pain. Materials and Methods: In a quasi-experimental design 75 patients referring to university-affiliated hospitals were randomly assigned to a control group, receiving no change in body position, group A subjected to changes in body position during and after ablation, and group B subjected to changes in body position during ablation. The intensity of pain, blood pressure, heart rate, and extent of bleeding and hematoma were measured. Results: The groups were not significantly different in terms of demographic characteristics, blood pressure, heart rate, overall bleeding, or hematoma at the entry into the coronary care unit. While not significantly different from each other, the intensity of back pain between group A and B were significantly lower than that of group C. Compared to group C, group A and B had a significantly lower pain score up to 6 and 4 h after the procedure, respectively. Group B had a significantly higher pain score at 2, 4, and 6 h post ablation than group A. Conclusions: The findings show that changing the body position during and after the ablation procedure would reduce or prevent the back pain without increasing the chance of bleeding and hematoma. PMID:23983735

  8. Two-Year Follow-Up after Contact Force Sensing Radiofrequency Catheter and Second-Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation: A Comparative Single Centre Study.

    PubMed

    Kardos, Attila; Kis, Zsuzsanna; Som, Zoltan; Nagy, Zsofia; Foldesi, Csaba

    2016-01-01

    Background. There are little comparative data on catheter ablation of paroxysmal atrial fibrillation (AF) using the contact force radiofrequency (CF-RF) catheter versus the second-generation cryoballoon (CB2). Methods and results. This is a single center, retrospective, nonrandomized study of 98 patients with symptomatic, drug-refractory paroxysmal AF who underwent their first PVI ablation using either the CB2 (n = 40) or CF-RF (n = 58). The mean age was 60 years with 63% men, a mean LA size of 42 mm. The procedure duration (74 ± 17 versus 120 ± 49 minutes p < 0.05) was shorter for CB2 group; the fluoroscopy time (14 ± 17 versus 16 ± 5 minutes, p = 0.45) was similar. Complete PVI was achieved in 96% of patients with RF-CF and 98% with CB2. Phrenic nerve palsies (2 transient and 1 persistent) occurred exclusively in the CB2 group and 1 severe, nonlethal complication (pericardial tamponade) occurred in the CF-RF group. At 24-month follow-up, the success rate, defined as freedom from AF/atrial tachycardia (AT) after a single procedure without antiarrhythmic drug, was comparable in CF-RF group and CB2 group (65.5% versus 67%, resp., log rank p = 0.54). Conclusion. Both the CB2 and the RF-CF ablation appeared safe; the success rate at 2 years was comparable between both technologies. PMID:27314032

  9. Two-Year Follow-Up after Contact Force Sensing Radiofrequency Catheter and Second-Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation: A Comparative Single Centre Study

    PubMed Central

    Kardos, Attila; Kis, Zsuzsanna; Som, Zoltan; Nagy, Zsofia; Foldesi, Csaba

    2016-01-01

    Background. There are little comparative data on catheter ablation of paroxysmal atrial fibrillation (AF) using the contact force radiofrequency (CF-RF) catheter versus the second-generation cryoballoon (CB2). Methods and results. This is a single center, retrospective, nonrandomized study of 98 patients with symptomatic, drug-refractory paroxysmal AF who underwent their first PVI ablation using either the CB2 (n = 40) or CF-RF (n = 58). The mean age was 60 years with 63% men, a mean LA size of 42 mm. The procedure duration (74 ± 17 versus 120 ± 49 minutes p < 0.05) was shorter for CB2 group; the fluoroscopy time (14 ± 17 versus 16 ± 5 minutes, p = 0.45) was similar. Complete PVI was achieved in 96% of patients with RF-CF and 98% with CB2. Phrenic nerve palsies (2 transient and 1 persistent) occurred exclusively in the CB2 group and 1 severe, nonlethal complication (pericardial tamponade) occurred in the CF-RF group. At 24-month follow-up, the success rate, defined as freedom from AF/atrial tachycardia (AT) after a single procedure without antiarrhythmic drug, was comparable in CF-RF group and CB2 group (65.5% versus 67%, resp., log rank p = 0.54). Conclusion. Both the CB2 and the RF-CF ablation appeared safe; the success rate at 2 years was comparable between both technologies. PMID:27314032

  10. Impact of Additional Transthoracic Electrical Cardioversion on Cardiac Function and Atrial Fibrillation Recurrence in Patients with Persistent Atrial Fibrillation Who Underwent Radiofrequency Catheter Ablation

    PubMed Central

    Wang, Deguo; Zhang, Fengxiang; Wang, Ancai

    2016-01-01

    Backgrounds and Objective. During the procession of radiofrequency catheter ablation (RFCA) in persistent atrial fibrillation (AF), transthoracic electrical cardioversion (ECV) is required to terminate AF. The purpose of this study was to determine the impact of additional ECV on cardiac function and recurrence of AF. Methods and Results. Persistent AF patients received extensive encircling pulmonary vein isolation (PVI) and additional line ablation. Patients were divided into two groups based on whether they need transthoracic electrical cardioversion to terminate AF: electrical cardioversion (ECV group) and nonelectrical cardioversion (NECV group). Among 111 subjects, 35 patients were returned to sinus rhythm after ablation by ECV (ECV group) and 76 patients had AF termination after the ablation processions (NECV group). During the 12-month follow-ups, the recurrence ratio of patients was comparable in ECV group (15/35) and NECV group (34/76) (44.14% versus 44.74%, P = 0.853). Although left atrial diameters (LAD) decreased significantly in both groups, there were no significant differences in LAD and left ventricular cardiac function between ECV group and NECV group. Conclusions. This study revealed that ECV has no significant impact on the maintenance of SR and the recovery of cardiac function. Therefore, ECV could be applied safely to recover SR during the procedure of catheter ablation of persistent atrial fibrillation. PMID:27022500

  11. Characterization of Pulmonary Vein Dimensions Using High-Definition 64-Slice Computed Tomography prior to Radiofrequency Catheter Ablation for Atrial Fibrillation

    PubMed Central

    Stähli, Barbara E.; Klaeser, Bernd; Fuchs, Tobias A.; Ghadri, Jelena R.; Lüscher, Thomas F.; Kaufmann, Philipp A.; Duru, Firat

    2014-01-01

    Background. Contrast-enhanced computed tomography is commonly acquired before radiofrequency catheter ablation (RFCA) for atrial fibrillation (AFib) to guide the procedure. We analyzed pulmonary vein (PV) ostial diameter and volumes on a high-definition 64-slice CT (HDCT) scanner in patients with AFib prior to RFCA. Methods and Results. This retrospective study included 50 patients (mean age 60.2 ± 11.4 years, 30 males) undergoing cardiac HDCT scanning before RFCA for drug refractory AFib and 50 age-, BMI-, and sex-matched controls with normal sinus rhythm undergoing HDCT. PV ostial diameter and volume were measured and calculated using a semiautomatic calliper tool. Total ostial PV volume was significantly increased in patients with AFib as compared to controls (P < 0.005). Similarly, total ostial PV diameter was significantly increased in AFib compared to controls (P < 0.001). In AFib, the largest PV volume and diameters were measured in right superior PV (P < 0.05 versus controls). The difference in PV volume between patients and controls was most pronounced in right superior PVs (P = 0.015). Right middle PVs were found more often in patients with AFib (16/50; 32%) than in normal subjects (7/50; 14%). Conclusion. Enlargement of PV ostial area and enlargement of volume are frequent findings in patients with drug refractory AFib. These parameters may add to the risk stratification for AFib recurrence following RFCA. PMID:25089213

  12. The Effects of Catheter-Based Radiofrequency Renal Denervation on Renal Function and Renal Artery Structure in Patients With Resistant Hypertension

    PubMed Central

    Zhang, Zhi-Hui; Yang, Kan; Jiang, Feng-Lin; Zeng, Li-Xiong; Jiang, Wei-Hong; Wang, Xiao-Yan

    2014-01-01

    There are no clinical studies on the effects of catheter-based radiofrequency renal denervation (RDN) on renal artery structure using 64-detector computed tomography (CT). A total of 39 patients with resistant hypertension received RDN and 38 patients received drug treatment. Mean systolic pressure and diastolic pressure in the RDN group decreased after 1, 3, 6, and 12 months of procedure (P<.05) and urinary protein level significantly decreased after 6 and 12 months (P<.05). The diameter, length, and sectional area of the renal artery; number of cases of atherosclerosis; and plaque burden of 64-detector CT renal arteriography did not change at 12 months of follow-up (P<.05), whereas the plaque burden increased significantly in the control group (P<.05). RDN significantly and persistently reduced blood pressure and decreased urinary protein excretion rate in patients with resistant hypertension and did not exhibit any adverse effect on renal function and renal artery structure. PMID:25039997

  13. Adenosine-induced atrioventricular block: a rapid and reliable method to assess surgical and radiofrequency catheter ablation of accessory atrioventricular pathways.

    PubMed

    Keim, S; Curtis, A B; Belardinelli, L; Epstein, M L; Staples, E D; Lerman, B B

    1992-04-01

    Adenosine has been shown to inhibit anterograde and retrograde conduction through the atrioventricular (AV) node while having little or no effect on accessory pathway conduction. Its rapid onset of action and short half-life make it particularly suitable for repetitive measurements. In this study, the utility of adenosine was tested in assessing completeness of accessory pathway ablation. Sixteen patients with an accessory pathway were studied (eight surgical ablations, eight catheter ablations with radiofrequency energy). Before ablation, no accessory pathway was sensitive to adenosine. Twelve patients with pre-excitation showed high grade AV node block with maximal pre-excitation on the administration of adenosine during atrial pacing. Four patients with a concealed accessory pathway demonstrated high grade AV block without evidence of latent anterograde accessory pathway conduction. Preablation ventriculoatrial (VA) block was not observed in any of the 16 patients in response to adenosine during ventricular pacing. Immediately after accessory pathway ablation, all patients developed AV and VA block with the administration of adenosine during atrial and ventricular pacing, respectively. These findings were confirmed during follow-up study 1 week later. Atrioventricular block during atrial and ventricular pacing with adenosine affords a reliable and immediate assessment of successful pathway ablation. PMID:1552087

  14. [Radiofrequency catheter ablation of an accessory atrioventricular conduction pathway with persistent left superior vena cava and hypertrophic cardiomyopathy].

    PubMed

    Neuser, H; Hofmann, E; Ebeling, F; Remp, T; Steinbeck, G

    1996-08-01

    A 43-year-old man with a 30-year history of WPW-syndrome and a hypertrophic cardiomyopathy developed acute heart failure after onset of atrial fibrillation with fast antegrade conduction, which could be converted to sinus rhythm with antiarrhythmic medication. Catheterization of the coronary sinus during EP testing demonstrated a persistent left superior vena cava. The accessory pathway could be localized at the orifice of an atypical epicardial vein. It was successfully abolished after subvalvular placement of the electrode catheter in the left ventricle. This constellation indicates a combined defect during the regression of the sinus venosus to the sinus coronarius with persistence of conducting muscle fibers. Successful RF ablation procedure provides an obvious risk reduction as a result of a lower frequency of atrial fibrillation and the eliminated risk of ventricular fibrillation due to rapid conduction via an accessory pathway. Beyond that, harmless therapeutic treatment of hypertrophic cardiomyopathy with a calcium-channel-blocker (verapamil type) can follow RF ablation. PMID:8975500

  15. Safety and efficacy of multipolar pulmonary vein ablation catheter vs. irrigated radiofrequency ablation for paroxysmal atrial fibrillation: a randomized multicentre trial

    PubMed Central

    McCready, J.; Chow, A. W.; Lowe, M. D.; Segal, O. R.; Ahsan, S.; de Bono, J.; Dhaliwal, M.; Mfuko, C.; Ng, A.; Rowland, E. R.; Bradley, R. J. W.; Paisey, J.; Roberts, P.; Morgan, J. M.; Sandilands, A.; Yue, A.; Lambiase, P. D.

    2014-01-01

    Aims The current challenge in atrial fibrillation (AF) treatment is to develop effective, efficient, and safe ablation strategies. This randomized controlled trial assesses the medium-term efficacy of duty-cycled radiofrequency ablation via the circular pulmonary vein ablation catheter (PVAC) vs. conventional electro-anatomically guided wide-area circumferential ablation (WACA). Methods and results One hundred and eighty-eight patients (mean age 62 ± 12 years, 116 M : 72 F) with paroxysmal AF were prospectively randomized to PVAC or WACA strategies and sequentially followed for 12 months. The primary endpoint was freedom from symptomatic or documented >30 s AF off medications for 7 days at 12 months post-procedure. One hundred and eighty-three patients completed 12 m follow-up. Ninety-four patients underwent PVAC PV isolation with 372 of 376 pulmonary veins (PVs) successfully isolated and all PVs isolated in 92 WACA patients. Three WACA and no PVAC patients developed tamponade. Fifty-six percent of WACA and 60% of PVAC patients were free of AF at 12 months post-procedure (P = ns) with a significant attrition rate from 77 to 78%, respectively, at 6 months. The mean procedure (140 ± 43 vs. 167 ± 42 min, P<0.0001), fluoroscopy (35 ± 16 vs. 42 ± 20 min, P<0.05) times were significantly shorter for PVAC than for WACA. Two patients developed strokes within 72 h of the procedure in the PVAC group, one possibly related directly to PVAC ablation in a high-risk patient and none in the WACA group (P = ns). Two of the 47 patients in the PVAC group who underwent repeat ablation had sub-clinical mild PV stenoses of 25–50% and 1 WACA patient developed delayed severe PV stenosis requiring venoplasty. Conclusion The pulmonary vein ablation catheter is equivalent in efficacy to WACA with reduced procedural and fluoroscopy times. However, there is a risk of thrombo-embolic and pulmonary stenosis complications which needs to be addressed and prospectively monitored. Clinical

  16. Urinary catheters

    MedlinePlus

    ... provider's office. An indwelling catheter has a small balloon inflated on the end of it. This prevents ... When the catheter needs to be removed, the balloon is deflated. CONDOM CATHETERS Condom catheters can be ...

  17. Using Conventional Sequences in L2 French

    ERIC Educational Resources Information Center

    Forsberg, Fanny

    2010-01-01

    By means of a phraseological identification method, this study provides a general description of the use of conventional sequences (CSs) in interviews at four different levels of spoken L2 French as well as in interviews with native speakers. Use of conventional sequences is studied with regard to overall quantity, category distribution and type…

  18. Advances in Radiofrequency Ablation of the Cerebral Cortex in Primates Using the Venous System: Improvements for Treating Epilepsy with Catheter Ablation Technology

    PubMed Central

    Henz, Benhur D.; Friedman, Paul A.; Bruce, Charles J.; Holmes, David R.; Bower, Mark; Madhavan, Malini; DeSimone, Christopher V.; Wahnschaffe, Douglas; Berhow, Steven; Danielsen, Andrew J.; Ladewig, Dorothy J.; Mikell, Susan B.; Johnson, Susan B.; Suddendorf, Scott H.; Kara, Tomas; Worrell, Gregory A.; Asirvatham, Samuel J.

    2015-01-01

    Background Pharmacology frequently fails for the treatment of epilepsy. Although surgical techniques are effective, these procedures are highly invasive. We describe feasibility and efficacy of minimally invasive mapping and ablation for the treatment of epilepsy. Methods Mapping and radiofrequency ablations were performed via the venous system in eleven baboons and three dogs. Results Mapping in deep cerebral areas was obtained in all animals. High-frequency pacing was able to induce seizure activity of local cerebral tissue in 72% of our attempts. Cerebral activity could be seen during mapping. Ablative lesions were deployed at deep brain sites without steam pops or sudden impedance rise. Histologic analysis showed necrosis at the sites of ablation in all primates. Conclusion Navigation through the cerebral venous system to map seizure activity is feasible. Radiofrequency energy can be delivered transvenously or transcortically to successful ablate cortical tissue in this animal model using this innovative approach. PMID:24836846

  19. [Catheter ablation of atrial flutter and paroxysmal atrial fibrillation].

    PubMed

    Márquez, Manlio F

    2003-01-01

    Radiofrequency catheter ablation has emerged as a curative therapy for atrial flutter based on studies demonstrating the role of the cavotricuspid isthmus. With a high rate of success and minimal complications, catheter ablation is the therapy of choice for patients with the common type of atrial flutter. Left atrial flutter, non-cavotricuspid isthmus dependent, and those associated with heart disease have a worst outcome with catheter ablation. Radiofrequency catheter ablation has also emerged as a curative therapy for paroxysmal atrial fibrillation based on studies demonstrating the role of triggering foci in the pulmonary veins for the initiation of atrial fibrillation. Catheter ablation is performed by a transseptal approach using radiofrequency energy at the ostium of each pulmonary vein. Mapping is guided by special catheters. Sequential radiofrequency applications eliminates or dissociates pulmonary vein muscle activity. Although complications exists, this is the only curative method for these patients. PMID:12966653

  20. Is dabigatran efficacy enough to prevent stroke in atrial fibrillation patient with high CHADS2 score during peri-procedural catheter radiofrequency ablation? A case report with literature review

    PubMed Central

    Shi, Xiang-Min; Chen, Fu-Kun; Liang, Zhuo; Li, Jian; Lin, Kun; Guo, Jian-Ping; Shan, Zhao-Liang

    2015-01-01

    Atrial fibrillation (AF) is a major cause of thromboembolic (TE) events including stroke and transient ischemic attacks, catheter radiofrequency ablation (CA) has been demonstrated to effectively eliminate AF in majority of patients. During the peri-procedural CA of AF, dabigatran, a reversible direct thrombin inhibitor, has been proved as safe and efficacy as warfarin in the prevention of thromboembolic complication. However, for patients with CHADS2 score ≥3, sometimes dabigatran may not be an ideal substitute of warfarin. The current study presents delayed stroke occurred in a middle-aged AF patient with high CHADS2 score who had undergone successful CA of AF being on dabigatran, trans esophageal echocardiogram (TEE) detected a clot in the left atrium appendage (LAA) and magnetic resonance image (MRI) indicated stroke of left basal ganglia, therefore anticoagulant was switched to warfarin with well controlled international normalization ratio (INR) ranging from 2.0-3.0 and the patient eventually recovered without any TE events during the subsequent follow-up. PMID:26131290

  1. Polymorphism rs2200733 at chromosome 4q25 is associated with atrial fibrillation recurrence after radiofrequency catheter ablation in the Chinese Han population

    PubMed Central

    Chen, Feifei; Yang, Yanzong; Zhang, Rongfeng; Zhang, Shulong; Dong, Yingxue; Yin, Xiaomeng; Chang, Dong; Yang, Zhiqiang; Wang, Kejing; Gao, Lianjun; Xia, Yunlong

    2016-01-01

    To test polymorphisms rs2200733 (chromosome 4q25) and rs2106261 (ZFHX3) were associated with AF recurrence after catheter ablation in a Chinese Han cohort. A total of 235 AF patients who underwent catheter ablation were recruited consecutively. Two polymorphisms were amplified by polymerase chain reaction and genotyped using high resolution melting analysis. Primary endpoints for AF recurrence were defined as the time to the first recurrence of atrial tachycardia/flutter/fibrillation (AT/AF). AT/AF recurrence was observed in 76 patients (35%). Allelic analysis demonstrated that rs2200733 was strongly associated with AF recurrence after ablation (P = 0.011) and the minor allele T increased the risk for recurrence (OR = 1.715). Diameters of the right atrium as well as the left and right superior pulmonary veins (PVs) were associated with rs2200733 in different genetic models (P = 0.040, 0.047 and 0.028, respectively). No significant association was detected between rs2106261 and AT/AF recurrence after ablation or atrial/PV diameters in any models. On multivariate Cox regression analysis, only rs2200733 was an independent factor of AF recurrence after ablation (HR = 0.532, P = 0.022). In Chinese Han population, rs2200733 but not rs2106261 is associated with AT/AF recurrence after ablation. The patients with genotype TT have larger size of right atrium and superior PVs than those of CC genotype. The findings suggest that rs2200733 may play a key role in regulating proper development and differentiation of atria/PVs. PMID:27158361

  2. Umbilical catheters

    MedlinePlus

    ... pregnancy. Two arteries and one vein in the umbilical cord carry blood back and forth. If the ... catheter is a long, soft, hollow tube. An umbilical artery catheter (UAC) allows blood to be taken ...

  3. Urinary catheters

    MedlinePlus

    ... that you use a catheter if you have: Urinary incontinence (leaking urine or being unable to control when ... Surgery Bladder Diseases Spinal Cord Injuries Urethral Disorders Urinary Incontinence Urine and Urination Browse the Encyclopedia A.D. ...

  4. Catheter Angiography

    MedlinePlus

    ... Catheter Angiography? Angiography is a minimally invasive medical test that helps physicians diagnose and treat medical conditions. Angiography uses one of three imaging technologies and, in most cases, a contrast material injection ...

  5. Esophageal papilloma: Flexible endoscopic ablation by radiofrequency

    PubMed Central

    del Genio, Gianmattia; del Genio, Federica; Schettino, Pietro; Limongelli, Paolo; Tolone, Salvatore; Brusciano, Luigi; Avellino, Manuela; Vitiello, Chiara; Docimo, Giovanni; Pezzullo, Angelo; Docimo, Ludovico

    2015-01-01

    Squamous papilloma of the esophagus is a rare benign lesion of the esophagus. Radiofrequency ablation is an established endoscopic technique for the eradication of Barrett esophagus. No cases of endoscopic ablation of esophageal papilloma by radiofrequency ablation (RFA) have been reported. We report a case of esophageal papilloma successfully treated with a single session of radiofrequency ablation. Endoscopic ablation of the lesion was achieved by radiofrequency using a new catheter inserted through the working channel of endoscope. The esophageal ablated tissue was removed by a specifically designed cup. Complete ablation was confirmed at 3 mo by endoscopy with biopsies. This case supports feasibility and safety of as a new potential indication for BarrxTM RFA in patients with esophageal papilloma. PMID:25789102

  6. Conservative Management of Left Atrial Intramural Hematoma after Catheter Ablation

    PubMed Central

    Oraii, Saeed; Roshanali, Farideh; Ghorbanisharif, Alireza; Mikaeili, Javad; Tahraei, Mahmood

    2016-01-01

    Left atrial intramural hematoma is a very rare complication of radiofrequency ablation procedures. A patient with tachyarrhythmia underwent radiofrequency catheter ablation. Echocardiography performed the following morning showed a large mass in the left atrium, suggestive of intramural hematoma formation. The patient was in a stable condition; therefore, it was decided that follow-up should be conservative and her anticoagulation therapy was continued. The size of the hematoma decreased significantly over the following 50 days. This case highlights a rare complication of a complex catheter ablation procedure in the left atrium that was managed via a noninvasive approach, with which all interventionists should be familiar. PMID:27482270

  7. Thermal compression and molding of atherosclerotic vascular tissue with use of radiofrequency energy: implications for radiofrequency balloon angioplasty

    SciTech Connect

    Lee, B.I.; Becker, G.J.; Waller, B.F.; Barry, K.J.; Connolly, R.J.; Kaplan, J.; Shapiro, A.R.; Nardella, P.C.

    1989-04-01

    The combined delivery of pressure and thermal energy may effectively remodel intraluminal atherosclerotic plaque and fuse intimal tears. To test these hypotheses with use of a non-laser thermal energy source, radiofrequency energy was delivered to postmortem human atherosclerotic vessels from a metal hot-tip catheter, block-mounted bipolar electrodes and from a prototype radiofrequency balloon catheter. Sixty-two radiofrequency doses delivered from a metal electrode tip produced dose-dependent ablation of atherosclerotic plaque, ranging from clean and shallow craters with histologic evidence of thermal compression at doses less than 40 J to tissue charring and vaporization at higher (greater than 80 J) doses. Lesion dimensions ranged between 3.14 and 3.79 mm in diameter and 0.20 and 0.47 mm in depth. Tissue perforation was not observed. To test the potential for radiofrequency fusion of intimal tears, 5 atm of pressure and 200 J radiofrequency energy were delivered from block-mounted bipolar electrodes to 48 segments of human atherosclerotic aorta, which had been manually separated into intima-media and media-adventitial layers. Significantly stronger tissue fusion resulted (28.5 +/- 3.3 g) with radiofrequency compared with that with pressure alone (4.8 +/- 0.26 g; p less than 0.0001). A prototype radiofrequency balloon catheter was used to deliver 3 atm of balloon pressure with or without 200 J radiofrequency energy to 20 postmortem human atherosclerotic arterial segments. In 10 of 10 radiofrequency-treated vessels, thermal molding of both normal and atherosclerotic vessel wall segments resulted with increased luminal diameter and histologic evidence of medial myocyte damage.

  8. Central venous catheters - ports

    MedlinePlus

    Central venous catheter - subcutaneous; Port-a-Cath; InfusaPort; PasPort; Subclavian port; Medi - port; Central venous line - port ... catheter is attached to a device called a port that will be under your skin. The port ...

  9. [Suprapubic catheter insertion].

    PubMed

    Neumann, Eva; Schwentner, Christian

    2016-01-01

    The suprapubic catheter enables a percutaneous drainage of urine. The insertion is made superior of the pubic bone through the abdominal wall into the bladder. It allows a permanent drainage of urine bypassing the urethra. The insertion of a suprapubic catheter requires knowledge and expertise. This paper summarizes the basic background and allows to follow the practical application step by step. PMID:26800072

  10. Radiofrequency Ablation of Liver Tumors

    MedlinePlus

    ... Other equipment such as needle electrodes, an electrical generator and grounding pads may also be used. Radiofrequency ... retractable electrodes that extend when needed. The radiofrequency generator produces electrical currents in the range of radiofrequency ...

  11. Cryo-balloon catheter localization in fluoroscopic images

    NASA Astrophysics Data System (ADS)

    Kurzendorfer, Tanja; Brost, Alexander; Jakob, Carolin; Mewes, Philip W.; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2013-03-01

    Minimally invasive catheter ablation has become the preferred treatment option for atrial fibrillation. Although the standard ablation procedure involves ablation points set by radio-frequency catheters, cryo-balloon catheters have even been reported to be more advantageous in certain cases. As electro-anatomical mapping systems do not support cryo-balloon ablation procedures, X-ray guidance is needed. However, current methods to provide support for cryo-balloon catheters in fluoroscopically guided ablation procedures rely heavily on manual user interaction. To improve this, we propose a first method for automatic cryo-balloon catheter localization in fluoroscopic images based on a blob detection algorithm. Our method is evaluated on 24 clinical images from 17 patients. The method successfully detected the cryoballoon in 22 out of 24 images, yielding a success rate of 91.6 %. The successful localization achieved an accuracy of 1.00 mm +/- 0.44 mm. Even though our methods currently fails in 8.4 % of the images available, it still offers a significant improvement over manual methods. Furthermore, detecting a landmark point along the cryo-balloon catheter can be a very important step for additional post-processing operations.

  12. Catheter selection for ablation of the cavotricuspid isthmus for treatment of typical atrial flutter.

    PubMed

    Da Costa, Antoine; Jamon, Yann; Romeyer-Bouchard, Cécile; Thévenin, Jérôme; Messier, Marc; Isaaz, Karl

    2006-11-01

    Radiofrequency catheter ablation (RFA) represents the first line therapy of the cavotricuspid isthmus-dependent atrial flutter (CTI-AFL) with a high efficacy and low secondary effects. RFA of CTI-dependent AFL can be performed by using various types of ablation catheters. Recent evaluations comparing externally cooled tip RFA (ecRFA) catheters and large-tip (8 mm) catheters have revealed that these catheters have a higher efficacy for CTI-AFL ablation compared to 4-mm catheters. The reliability of RFA catheters for AFL is variable and an optimal catheter selection may enhance the RFA effectiveness. The main goal of this article is to review the elements that improve the management of CTI RFA. Preliminary examinations of histopathologic and anatomical elements that may interfere with conventional CTI RFA are presented. Experimental studies concerning the electrobiology of large-tip and cooled-tip catheters are compared. The different catheter designs between cooled-tip and 8-mm-tip catheters are examined (size of the deflectable curve, rotation stability, and size of the distal nonsteerable catheter part) because of their critical role in CTI RFA results. A thorough review of clinical trials of each catheter is presented, and comparison of both catheters in this clinical setting is analyzed. In addition, the role of CTI morphology on AFL RF duration is underlined such as the value of right atrial angiography as an adjunct tool for CTI RFA catheter selection. Based on randomized studies, 8-mm-tip catheters seem to be more effective for ablation in case of straight angiographic isthmus morphology. On the other hand, ecRFA catheters appear to be more effective in cases of complex CTI anatomy or difficult CTI RFA. To reduce X-ray exposition and RFA application time, few studies report that CTI angiographic evaluation before RFA allows a catheter selection based on both CTI morphology and length. Moreover, preliminary data of randomized studies showed that an

  13. Auditing urinary catheter care.

    PubMed

    Dailly, Sue

    Urinary catheters are the main cause of hospital-acquired urinary tract infections among inpatients. Healthcare staff can reduce the risk of patients developing an infection by ensuring they give evidence-based care and by removing the catheter as soon as it is no longer necessary. An audit conducted in a Hampshire hospital demonstrated there was poor documented evidence that best practice was being carried out. Therefore a urinary catheter assessment and monitoring tool was designed to promote best practice and produce clear evidence that care had been provided. PMID:22375340

  14. Sinuplasty (Balloon Catheter Dilation)

    MedlinePlus

    ... development of the balloon dilating catheter and its adaptation to sinus surgery. In the 1980s, the field ... used in endoscopic sinus surgery. It is the adaptation or application of minimally-invasive balloon technology to ...

  15. Suprapubic catheter care

    MedlinePlus

    ... store. Other supplies you will need are sterile gloves, a catheter pack, syringes, sterile solution to clean ... your back. Put on two pairs of sterile gloves, one over the other. Then: Make sure your ...

  16. Indwelling catheter care

    MedlinePlus

    ... Common reasons to have an indwelling catheter are urinary incontinence (leakage), urinary retention (not being able to urinate), ... gov/pubmed/22094023 . Read More Radical prostatectomy Stress urinary incontinence Transurethral resection of the prostate Urge incontinence Urinary ...

  17. Suprapubic catheter care

    MedlinePlus

    ... You may need a catheter because you have urinary incontinence (leakage), urinary retention (not being able to urinate), ... vaginal wall repair Inflatable artificial sphincter Radical prostatectomy Urinary incontinence - injectable implant Urinary incontinence - retropubic suspension Urinary incontinence - ...

  18. Central venous catheter - flushing

    MedlinePlus

    ... To flush your catheter, you will need: Clean paper towels Saline syringes (clear), and maybe heparin syringes ( ... your fingers before washing. Dry with a clean paper towel. Set up your supplies on a clean ...

  19. [Urinary catheter biofilm infections].

    PubMed

    Holá, V; Růzicka, F

    2008-04-01

    Urinary tract infections, most of which are biofilm infections in catheterized patients, account for more than 40% of hospital infections. Bacterial colonization of the urinary tract and catheters causes not only infection but also other complications such as catheter blockage by bacterial encrustation, urolithiasis and pyelonephritis. About 50% of long-term catheterized patients face urinary flow obstruction due to catheter encrustation, but no measure is currently available to prevent it. Encrustation has been known either to result from metabolic dysfunction or to be of microbial origin, with urease positive bacterial species implicated most often. Infectious calculi account for about 15-20% of all cases of urolithiasis and are often associated with biofilm colonization of a long-term indwelling urinary catheter or urethral stent. The use of closed catheter systems is helpful in reducing such problems; nevertheless, such a system only delays the inevitable, with infections emerging a little later. Various coatings intended to prevent the bacterial adhesion to the surface of catheters and implants and thus also the emergence of biofilm infections, unfortunately, do not inhibit the microbial adhesion completely and permanently and the only reliable method for biofilm eradication remains the removal of the foreign body from the patient. PMID:18578409

  20. Cryo-balloon catheter position planning using AFiT

    NASA Astrophysics Data System (ADS)

    Kleinoeder, Andreas; Brost, Alexander; Bourier, Felix; Koch, Martin; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2012-02-01

    Atrial fibrillation (AFib) is the most common heart arrhythmia. In certain situations, it can result in life-threatening complications such as stroke and heart failure. For paroxsysmal AFib, pulmonary vein isolation (PVI) by catheter ablation is the recommended choice of treatment if drug therapy fails. During minimally invasive procedures, electrically active tissue around the pulmonary veins is destroyed by either applying heat or cryothermal energy to the tissue. The procedure is usually performed in electrophysiology labs under fluoroscopic guidance. Besides radio-frequency catheter ablation devices, so-called single-shot devices, e.g., the cryothermal balloon catheters, are receiving more and more interest in the electrophysiology (EP) community. Single-shot devices may be advantageous for certain cases, since they can simplify the creation of contiguous (gapless) lesion sets around the pulmonary vein which is needed to achieve PVI. In many cases, a 3-D (CT, MRI, or C-arm CT) image of a patient's left atrium is available. This data can then be used for planning purposes and for supporting catheter navigation during the procedure. Cryo-thermal balloon catheters are commercially available in two different sizes. We propose the Atrial Fibrillation Planning Tool (AFiT), which visualizes the segmented left atrium as well as multiple cryo-balloon catheters within a virtual reality, to find out how well cryo-balloons fit to the anatomy of a patient's left atrium. First evaluations have shown that AFiT helps physicians in two ways. First, they can better assess whether cryoballoon ablation or RF ablation is the treatment of choice at all. Second, they can select the proper-size cryo-balloon catheter with more confidence.

  1. Nanoscale memristive radiofrequency switches

    NASA Astrophysics Data System (ADS)

    Pi, Shuang; Ghadiri-Sadrabadi, Mohammad; Bardin, Joseph C.; Xia, Qiangfei

    2015-06-01

    Radiofrequency switches are critical components in wireless communication systems and consumer electronics. Emerging devices include switches based on microelectromechanical systems and phase-change materials. However, these devices suffer from disadvantages such as large physical dimensions and high actuation voltages. Here we propose and demonstrate a nanoscale radiofrequency switch based on a memristive device. The device can be programmed with a voltage as low as 0.4 V and has an ON/OFF conductance ratio up to 1012 with long state retention. We measure the radiofrequency performance of the switch up to 110 GHz and demonstrate low insertion loss (0.3 dB at 40 GHz), high isolation (30 dB at 40 GHz), an average cutoff frequency of 35 THz and competitive linearity and power-handling capability. Our results suggest that, in addition to their application in memory and computing, memristive devices are also a leading contender for radiofrequency switch applications.

  2. Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

    SciTech Connect

    Mizandari, Malkhaz; Ao, Guokun; Zhang Yaojun; Feng Xi; Shen Qiang; Chen Minshan; Lau, Wan Yee; Nicholls, Joanna; Jiao Long; Habib, Nagy

    2013-02-15

    We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus. There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.

  3. Peripherally inserted central catheter - insertion

    MedlinePlus

    ... central catheters and nontunneled central venous catheters. In: Mauro MA, Murphy KPJ, Thomson KR, et al., eds. ... Procedures . 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2007:chap 4. Mansour JC, Neiderhuber JE. Establishing and ...

  4. L1 (English) to L2 (French) Transfer: The Question of Nasalization

    ERIC Educational Resources Information Center

    Garrott, Carl L.

    2006-01-01

    The purpose of this investigation was to answer the following questions: (1) Do transfer and developmental errors decrease or increase during informal and formal tasks? (2) What nasal vowels present greater markedness for L2 French learners? and (3) Using recall as the dependent variable, will French nasals continue to be produced over a time…

  5. Beginners' Progress in Decoding L2 French: Some Longitudinal Evidence from English Modern Foreign Languages Classrooms

    ERIC Educational Resources Information Center

    Woore, Robert

    2009-01-01

    "Decoding"--converting the written symbols (or graphemes) of an alphabetical writing system into the sounds (or phonemes) they represent, using knowledge of the language's symbol/sound correspondences--has been argued to be an important but neglected skill in the teaching of second language (L2) French in English secondary schools. Previous…

  6. The Development of Complexity, Accuracy and Fluency in the Written Production of L2 French

    ERIC Educational Resources Information Center

    Gunnarsson, Cecilia

    2012-01-01

    The present longitudinal case study investigated the development of fluency, complexity and accuracy--and the possible relationships between them--in the written production of L2 French. We assessed fluency and complexity in five intermediate learners by means of conventional indicators for written L2 (cf. Wolfe-Quintero et al. 1998), while…

  7. Indwelling catheter care

    MedlinePlus

    ... clean between your fingers and under your nails. Wet one of the washcloths with warm water and soap it up. Gently wash all around the area where the catheter goes in with the soapy washcloth. Females should wipe from front to back. Males should wipe from ...

  8. Catheter-related bloodstream infection.

    PubMed

    Goede, Matthew R; Coopersmith, Craig M

    2009-04-01

    Catheter-related bloodstream infections (CR-BSIs) are a common, frequently preventable complication of central venous catheterization. CR-BSIs can be prevented by strict attention to insertion and maintenance of central venous catheters and removing unneeded catheters as soon as possible. Antiseptic- or antibiotic-impregnated catheters are also an effective tool to prevent infections. The diagnosis of CR-BSI is made largely based on culture results. CR-BSIs should always be treated with antibiotics, and except in rare circumstances the infected catheter needs to be removed. PMID:19281894

  9. The Growth of Complexity and Accuracy in L2 French: Past Observations and Recent Applications of Developmental Stages

    ERIC Educational Resources Information Center

    Agren, Malin; Granfeldt, Jonas; Schlyter, Suzanne

    2012-01-01

    This chapter addresses the question of the growth of accuracy and complexity in L2 French from the perspective of developmental sequences of morphosyntax, developmental stages and linguistic profiling. The six developmental stages for L2 French proposed by Bartning and Schlyter (2004) are presented and exemplified and new results are added to the…

  10. Radiofrequency Ablation of Lung Tumors

    MedlinePlus

    ... computed tomography (CT) imaging, needle electrodes , an electrical generator and grounding pads are used. There are two ... retractable electrodes that extend when needed. The radiofrequency generator produces electrical currents in the range of radiofrequency ...

  11. Development of a Novel Shock Wave Catheter Ablation System

    NASA Astrophysics Data System (ADS)

    Yamamoto, H.; Hasebe, Yuhi; Kondo, Masateru; Fukuda, Koji; Takayama, Kazuyoshi; Shimokawa, Hiroaki

    Although radio-frequency catheter ablation (RFCA) is quite effective for the treatment tachyarrhythmias, it possesses two fundamental limitations, including limited efficacy for the treatment of ventricular tachyarrhythmias of epicardial origin and the risk of thromboembolism. Consequently, new method is required, which can eradicate arrhythmia source in deep part of cardiac muscle without heating. On the other hand, for a medical application of shock waves, extracorporeal shock wave lithotripter (ESWL) has been established [1]. It was demonstrated that the underwater shock focusing is one of most efficient method to generate a controlled high pressure in a small region [2]. In order to overcome limitations of existing methods, we aimed to develop a new catheter ablation system with underwater shock waves that can treat myocardium at arbitrary depth without causing heat.

  12. Minimally Invasive Radiofrequency Devices.

    PubMed

    Sadick, Neil; Rothaus, Kenneth O

    2016-07-01

    This article reviews minimally invasive radiofrequency options for skin tightening, focusing on describing their mechanism of action and clinical profile in terms of safety and efficacy and presenting peer-reviewed articles associated with the specific technologies. Treatments offered by minimally invasive radiofrequency devices (fractional, microneedling, temperature-controlled) are increasing in popularity due to the dramatic effects they can have without requiring skin excision, downtime, or even extreme financial burden from the patient's perspective. Clinical applications thus far have yielded impressive results in treating signs of the aging face and neck, either as stand-alone or as postoperative maintenance treatments. PMID:27363771

  13. Catheter ablation of the accessory pathways of the Wolff-Parkinson-White syndrome and its variants.

    PubMed

    Plumb, V J

    1995-01-01

    The basis of arrhythmias in the Wolff-Parkinson-White (WPW) syndrome and its variants is the presence of accessory atrioventricular connections. Those variants include the concealed form of the WPW syndrome, the permanent form of junctional reciprocating tachycardia, and Mahaim preexcitation. In all forms of symptomatic WPW syndrome, catheter ablation of the accessory atrioventricular connections using radiofrequency current has become the treatment of choice. This review traces the development of this therapy, outlines the basics of the technique, summarizes the results reported in the largest series, indicate remaining areas of controversy, and discusses the indications and limitations of radiofrequency ablation therapy. PMID:7871178

  14. Catheter associated urinary tract infections

    PubMed Central

    2014-01-01

    Urinary tract infection attributed to the use of an indwelling urinary catheter is one of the most common infections acquired by patients in health care facilities. As biofilm ultimately develops on all of these devices, the major determinant for development of bacteriuria is duration of catheterization. While the proportion of bacteriuric subjects who develop symptomatic infection is low, the high frequency of use of indwelling urinary catheters means there is a substantial burden attributable to these infections. Catheter-acquired urinary infection is the source for about 20% of episodes of health-care acquired bacteremia in acute care facilities, and over 50% in long term care facilities. The most important interventions to prevent bacteriuria and infection are to limit indwelling catheter use and, when catheter use is necessary, to discontinue the catheter as soon as clinically feasible. Infection control programs in health care facilities must implement and monitor strategies to limit catheter-acquired urinary infection, including surveillance of catheter use, appropriateness of catheter indications, and complications. Ultimately, prevention of these infections will require technical advances in catheter materials which prevent biofilm formation. PMID:25075308

  15. The role of catheter ablation in the management of atrial fibrillation.

    PubMed

    Ang, Richard; Earley, Mark J

    2016-06-01

    Atrial fibrillation is driven by spontaneous electrical activation emerging from the pulmonary veins. Catheter ablation using either radiofrequency or cryothermal energy electrically isolates these veins from the left atrium, both reducing the burden of atrial fibrillation episodes and improving the patient's symptoms. Catheter ablation is superior to antiarryhthmic drugs when patients are carefully selected. Underlying medical problems - including obesity, hypertension and obstructive sleep apnoea - should be optimally treated before considering ablation. Although this treatment has the potential to cure patients of their symptoms, they should be aware of the important associated procedural complications. PMID:27251918

  16. Nanoscale memristive radiofrequency switches.

    PubMed

    Pi, Shuang; Ghadiri-Sadrabadi, Mohammad; Bardin, Joseph C; Xia, Qiangfei

    2015-01-01

    Radiofrequency switches are critical components in wireless communication systems and consumer electronics. Emerging devices include switches based on microelectromechanical systems and phase-change materials. However, these devices suffer from disadvantages such as large physical dimensions and high actuation voltages. Here we propose and demonstrate a nanoscale radiofrequency switch based on a memristive device. The device can be programmed with a voltage as low as 0.4 V and has an ON/OFF conductance ratio up to 10(12) with long state retention. We measure the radiofrequency performance of the switch up to 110 GHz and demonstrate low insertion loss (0.3 dB at 40 GHz), high isolation (30 dB at 40 GHz), an average cutoff frequency of 35 THz and competitive linearity and power-handling capability. Our results suggest that, in addition to their application in memory and computing, memristive devices are also a leading contender for radiofrequency switch applications. PMID:26108890

  17. A simple and fast technique for radiofrequency-assisted perforation of the atrial septum in congenital heart disease

    PubMed Central

    Sandoval, Juan Pablo; Chaturvedi, Rajiv R

    2016-01-01

    Radiofrequency (RF) assisted perforation of the atrial septum was performed successfully in three infants using a 0.035” RF wire deployed through a Williams right posterior catheter. Balloon atrial septoplasty was performed over the 0.035” RF wire in two of them, shortening the procedural time. PMID:27011690

  18. A simple and fast technique for radiofrequency-assisted perforation of the atrial septum in congenital heart disease.

    PubMed

    Sandoval, Juan Pablo; Chaturvedi, Rajiv R

    2016-01-01

    Radiofrequency (RF) assisted perforation of the atrial septum was performed successfully in three infants using a 0.035" RF wire deployed through a Williams right posterior catheter. Balloon atrial septoplasty was performed over the 0.035" RF wire in two of them, shortening the procedural time. PMID:27011690

  19. Thermistor guided radiofrequency ablation of atrial insertion sites in patients with accessory pathways.

    PubMed

    Tracy, C M; Moore, H J; Solomon, A J; Rodak, D J; Fletcher, R D

    1995-11-01

    Radiofrequency ablation has gained acceptance in the treatment of patients with symptomatic Wolff-Parkinson-White syndrome. The purpose of this study was to characterize the relation between temperature and other electroconductive parameters in patients undergoing atrial insertion accessory pathway ablation utilizing a thermistor equipped catheter. The mean temperature and power at sites of atrial insertion ablation are lower than has been previously associated with creation of radiofrequency lesions in the ventricle. While high cavitary blood flow in the atrium may result in cooling, the thinner atrial tissue may require less energy to achieve adequate heating than ventricular myocardium. PMID:8552513

  20. Should radiofrequency current ablation be performed in asymptomatic patients with the Wolff-Parkinson-White syndrome?

    PubMed

    Steinbeck, G

    1993-03-01

    The exiting new method of ablation of accessory pathways using radiofrequency current applied by catheters will dramatically change our therapeutic decisions in these patients in the near future. This brief survey reviews the existing literature about the risk of the disease as well as of the procedure of catheter ablation. From these data, the risk of sudden death appears to be extremely low in asymptomatic Wolff-Parkinson-White (WPW) individuals. Side effects of catheter ablation may result from the invasive procedure as well as from radiation exposure (the latter to the patient as well as to operating physicians). While the complication rate in experienced centers is extremely low, a multicenter registry of the success and complication rate is urgently needed in view of the many centers starting with catheter ablation. Based on a subjective benefit-to-risk analysis, asymptomatic WPW individuals should be offered catheter ablation only under special circumstances (high risk profession, athletes, family history of sudden death). On the other hand, catheter ablation need not be and should not be considered generally in asymptomatic individuals with WPW pattern. Finally, this author cannot imagine that the energy, time, and money spent for mass screening and eventual catheter ablation of asymptomatic WPW individuals with its attending risks can be outweighed by the potential benefits for these asymptomatic individuals. PMID:7681970

  1. FAQs about Catheter-Associated Bloodstream Infections

    MedlinePlus

    ... Wear a mask, cap, sterile gown, and sterile gloves when putting in the catheter to keep it ... putting in the catheter. • Clean their hands, wear gloves, and clean the catheter opening with an antiseptic ...

  2. Catheter Ablation Related Mitral Valve Injury: The Importance of Early Recognition and Rescue Mitral Valve Repair

    PubMed Central

    DeSimone, Christopher V.; Hu, Tiffany; Ebrille, Elisa; Syed, Faisal F.; Vaidya, Vaibhav R.; Cha, Yong-Mei; Valverde, Arturo M.; Friedman, Paul A.; Suri, Rakesh M.; Asirvatham, Samuel J.

    2015-01-01

    Introduction An increasing number of catheter ablations involve the mitral annular region and valve apparatus, increasing the risk of catheter interaction with the mitral valve (MV) complex. We review our experience with catheter ablation-related MV injury resulting in severe mitral regurgitation (MR) to delineate mechanisms of injury and outcomes. Methods We searched the Mayo Clinic mitral valve surgical database over a 19-year period (1993–2012) and the electrophysiologic procedures database over a 23-year period (1990–2013) and identified 9 patients with catheter ablation related MV injury requiring clinical intervention. Results Indications for ablation included atrial fibrillation (AF) [n=4], ventricular tachycardia (VT) [n =3], and left-sided accessory pathways [n=2]. In all 4 AF patients, a circular mapping catheter entrapped in the MV apparatus was responsible for severe mitral regurgitation. In all 3 VT patients, radiofrequency energy delivery led to direct injury to the MV apparatus. In the 2 patients with accessory pathways, both mechanisms were involved (1 per patient). Six patients required surgical intervention (5 MV repair, 1 catheter removal). One patient developed severe functional MR upon successful endovascular catheter disentanglement that improved spontaneously. Two VT patients with persistent severe post-ablation MR were managed non-surgically, one of whom died 3 months post-procedure. Conclusion Circular mapping catheter entrapment and ablation at the mitral annulus are the most common etiologies of MV injury during catheter ablation. Close surveillance of the MV is needed during such procedures and early surgical repair is important for successful salvage if significant injury occurs. PMID:24758402

  3. Heart catheter cable and connector

    NASA Technical Reports Server (NTRS)

    Harrison, D. R.; Cota, F. L.; Sandler, H.

    1972-01-01

    Ultraminiature catheter cables that are stiff enough for intravenous insertion yet flexible at the tip, sterilizable, and economical are fabricated entirely from commercially available parts. Assembly includes air passageway for reference pressures and coaxial cable for transmission of signals from the tip of catheter.

  4. Radiofrequency Ablation of Cancer

    PubMed Central

    Friedman, Marc; Mikityansky, Igor; Kam, Anthony; Libutti, Steven K.; Walther, McClellan M.; Neeman, Ziv; Locklin, Julia K.; Wood, Bradford J.

    2008-01-01

    Radiofrequency ablation (RFA) has been used for over 18 years for treatment of nerve-related chronic pain and cardiac arrhythmias. In the last 10 years, technical developments have increased ablation volumes in a controllable, versatile, and relatively inexpensive manner. The host of clinical applications for RFA have similarly expanded. Current RFA equipment, techniques, applications, results, complications, and research avenues for local tumor ablation are summarized. PMID:15383844

  5. Radiofrequency Ablation of Cancer

    SciTech Connect

    Friedman, Marc; Mikityansky, Igor; Kam, Anthony; Libutti, Steven K.; Walther, McClellan M.; Neeman, Ziv; Locklin, Julia K.; Wood, Bradford J.

    2004-09-15

    Radiofrequency ablation (RFA) has been used for over 18 years for treatment of nerve-related chronic pain and cardiac arrhythmias. In the last 10 years, technical developments have increased ablation volumes in a controllable, versatile, and relatively inexpensive manner. The host of clinical applications for RFA have similarly expanded. Current RFA equipment, techniques, applications, results, complications, and research avenues for local tumor ablation are summarized.

  6. Optimization of the generator settings for endobiliary radiofrequency ablation

    PubMed Central

    Barret, Maximilien; Leblanc, Sarah; Vienne, Ariane; Rouquette, Alexandre; Beuvon, Frederic; Chaussade, Stanislas; Prat, Frederic

    2015-01-01

    AIM: To determine the optimal generator settings for endobiliary radiofrequency ablation. METHODS: Endobiliary radiofrequency ablation was performed in live swine on the ampulla of Vater, the common bile duct and in the hepatic parenchyma. Radiofrequency ablation time, “effect”, and power were allowed to vary. The animals were sacrificed two hours after the procedure. Histopathological assessment of the depth of the thermal lesions was performed. RESULTS: Twenty-five radiofrequency bursts were applied in three swine. In the ampulla of Vater (n = 3), necrosis of the duodenal wall was observed starting with an effect set at 8, power output set at 10 W, and a 30 s shot duration, whereas superficial mucosal damage of up to 350 μm in depth was recorded for an effect set at 8, power output set at 6 W and a 30 s shot duration. In the common bile duct (n = 4), a 1070 μm, safe and efficient ablation was obtained for an effect set at 8, a power output of 8 W, and an ablation time of 30 s. Within the hepatic parenchyma (n = 18), the depth of tissue damage varied from 1620 μm (effect = 8, power = 10 W, ablation time = 15 s) to 4480 μm (effect = 8, power = 8 W, ablation time = 90 s). CONCLUSION: The duration of the catheter application appeared to be the most important parameter influencing the depth of the thermal injury during endobiliary radiofrequency ablation. In healthy swine, the currently recommended settings of the generator may induce severe, supratherapeutic tissue damage in the biliary tree, especially in the high-risk area of the ampulla of Vater. PMID:26566429

  7. Radiofrequency Guide Wire Recanalization of Venous Occlusions in Patients with Malignant Superior Vena Cava Syndrome

    SciTech Connect

    Davis, Robert M.; David, Elizabeth; Pugash, Robyn A.; Annamalai, Ganesan

    2012-06-15

    Fibrotic central venous occlusions in patients with thoracic malignancy and prior radiotherapy can be impassable with standard catheters and wires, including the trailing or stiff end of a hydrophilic wire. We report two patients with superior vena cava syndrome in whom we successfully utilized a radiofrequency guide wire (PowerWire, Baylis Medical, Montreal, Quebec, Canada) to perforate through the occlusion and recanalize the occluded segment to alleviate symptoms.

  8. Current and future modalities of catheter ablation for the treatment of cardiac arrhythmias.

    PubMed

    Haines, D E

    1992-01-01

    Catheter ablation has proven to be a safe and effective treatment for a wide variety of cardiac arrhythmias. By destroying the critical zone of conductive tissue responsible for impulse generation or propagation, the arrhythmias may be cured. A variety of modalities of catheter ablation have been tested in the past decade. Initially, high energy direct current shocks delivered through a conventional electrode catheter were used. Now, use of radiofrequency energy as a power supply has resulted in higher efficacy and much improved safety of this technique. New approaches including low energy direct current shock ablation, microwave hyperthermic ablation, and laser photocoagulation are being tested, and may result in further refinement of nonsurgical curative therapy of arrhythmias. PMID:10147817

  9. Microwave catheter design.

    PubMed

    Nevels, R D; Arndt, G D; Raffoul, G W; Carl, J R; Pacifico, A

    1998-07-01

    A microwave antenna system for transcatheter ablation of cardiac tissue is investigated. A numerical model based on the finite-difference time-domain method incorporating a Gaussian pulse excitation has been constructed and frequency domain electric and magnetic fields are obtained through Fourier transformation. Results are presented for a coaxial line fed monopole catheter which is modified by the successive inclusion of a Teflon sheath outer coating, a terminating disk at the tip of the antenna, a sleeve choke, and a high dielectric constant cylinder surrounding the monopole antenna. The effects of these design features are characterized in terms of specific absorption rate (SAR) and return loss (RL). Numerical calculations are confirmed by comparing with the RL measurement of a Teflon-coated monopole containing a disk and choke. PMID:9644897

  10. Balloon catheter coronary angioplasty

    SciTech Connect

    Angelini, P.

    1987-01-01

    The author has produced a reference and teaching book on balloon angioplasty. Because it borders in surgery and is performed on an awake patient without circulatory assistance, it is a complex and demanding procedure that requires thorough knowledge before it is attempted. The text is divided into seven sections. The first section describes coronary anatomy and pathophysiology, defines the objectives and mechanisms of the procedure and lists four possible physiologic results. The next section describes equipment in the catheterization laboratory, catheters, guidewires and required personnel. The following section is on the procedure itself and includes a discussion of examination, testing, technique and follow-up. The fourth section details possible complications that can occur during the procedure, such as coronary spasms, occlusion, thrombosis, perforations and ruptures, and also discusses cardiac surgery after failed angioplasty. The fifth section details complex or unusual cases that can occur. The sixth and seventh sections discuss radiation, alternative procedures and the future of angioplasty.

  11. [A comparative study between surgical section and radiofrequency ablation of the anomalous pathways in the WPW syndrome].

    PubMed

    Iturralde, P; Colín, L; Kershenovich, S; Saucedo, J; de Micheli, A; Barragán, R; Martínez Rios, M A; González Hermosillo, J A

    1993-01-01

    Radiofrequency catheter ablation is an effective alternative to medical therapy to patient with Wolff Parkinson White syndrome (WPW). The purpose of this study is to compare our results in 70 patients with WPW that underwent either surgery or ablation procedure with radiofrequency energy. Of this number of patients the surgical procedure was successful in 82%; complications were present in 15% and mortality in 8%. Average hospitalization was 6 to 10 days and cost from 2 to 10 thousand of new pesos. On the other hand, of 44 patients that underwent radiofrequency ablation, in 80% the procedure was finally successful with recurrence of 9% and no mortality. The hospitalization period was one day, the cost run from 500 to 2 thousand of new pesos in our institution. These results demonstrate the efficacy of the radiofrequency energy ablation in the treatment of WPW. This procedure is safe and less expensive than surgery. PMID:8466362

  12. [Catheter-related infections: microbiology].

    PubMed

    Timsit, J F

    2005-03-01

    Coagulase negative staphylococci, Staphylococcus aureus and Pseudomonas sp. are the most frequent microorganisms responsible for catheter-related infections. A relative frequency of microorganisms varies according to the countries, microenvironment and outbreaks of multiresistant bacterias. Infections due to fungi, S. aureus and Pseudomonas sp. are associated with the more severe complications. Recent data suggest that chlorhexidine, either used for cutaneous antisepsis or for catheter impregnation decreases infections due to gram positive cocci. Ecological data should be taken into account when deciding a probabilistic treatment in case of suspicion of catheter-related infection. PMID:15792563

  13. [Radiofrequency ablation in tachycardias due to accessory pathways in a pediatric population].

    PubMed

    Iturralde, P; Saucedo, J; Colín, L; Kershenovich, S; Robledo, R; Garrido, A; González-Hermosillo, J A; Buendía, A

    1994-01-01

    Catheter ablation of accessory atrioventricular pathways using radiofrequency current was attempted in 61 children and young adolescents less than 18 years of age who were referred for treatment of symptomatic supraventricular tachycardia. Thirty-three children had the Wolff-Parkinson-White syndrome and 30 tachyarrhythmias related to an accessory pathway conducting only in retrograde fashion. Ablation of left sided accessory pathways was usually attempted utilizing an arterial approach to the annulus of the mitral valve, only in one case we used the transseptal approach, while the venous route to the atrial aspect of the tricuspid valvular annulus was chosen for right sided accessory connections. Ablation of 55 of 63 accessory connections was achieved (87% success) with a range of 1 to 42 applications of radiofrequency current. The sessions were completed within 19 to 180 minutes, and we used within 16 to 45 watts of radiofrequency current. Two patients had complications as a result of their ablation procedure. One patient had complete heart block but did not require pacemaker implantation, and other one had mitral regurgitation. A second session was necessary in three patients, two of three accessory pathways were ablated, giving a success rate of 90%. During a one year period of follow-up, we had 4 recurrences (7.2%). Catheter ablation using radiofrequency current is a highly effective and safe curative approach for treating young patients with supraventricular tachycardia mediated by accessory pathways. PMID:7840718

  14. Radiofrequency in cosmetic dermatology.

    PubMed

    Beasley, Karen L; Weiss, Robert A

    2014-01-01

    The demand for noninvasive methods of facial and body rejuvenation has experienced exponential growth over the last decade. There is a particular interest in safe and effective ways to decrease skin laxity and smooth irregular body contours and texture without downtime. These noninvasive treatments are being sought after because less time for recovery means less time lost from work and social endeavors. Radiofrequency (RF) treatments are traditionally titrated to be nonablative and are optimal for those wishing to avoid recovery time. Not only is there minimal recovery but also a high level of safety with aesthetic RF treatments. PMID:24267424

  15. In vivo intracardiac OCT imaging through percutaneous access: towards image guided radio-frequency ablation

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Kang, Wei; Carrigan, Thomas; Bishop, Austin; Rosenthal, Noah; Arruda, Mauricio; Rollins, Andrew M.

    2012-01-01

    BACKGROUND Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. We aim to develop optical coherence tomography (OCT) as an imaging guidance for RFA. OBJECTIVES The purpose of this study is to evaluate the feasibility of using OCT catheter to image endocardia wall in active beating hearts through percutaneous access. This is a critical step toward image guided RFA in a clinic setting. METHODS A cone-scanning forward-viewing OCT catheter was advanced into active beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardia wall. The images were then acquired at 10 frames per second at an axial resolution and lateral resolution of 15 μm. RESULTS We report the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. We are able to acquire high quality OCT images in active beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium and readily evaluate catheter-tissue contact. CONCLUSIONS It is feasible to acquire OCT images in beating hearts through percutaneous access. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.

  16. Temperature-controlled cooled-tip radiofrequency ablation in left ventricular myocardium.

    PubMed

    Watanabe, Ichiro; Nuo, Min; Okumura, Yasuo; Ohkubo, Kimie; Ashino, Sonoko; Kofune, Masayoshi; Kofune, Tatsuya; Nakai, Toshiko; Kasamaki, Yuji; Hirayama, Atsushi

    2010-05-01

    Steam pop and intramural charring have been reported during cooled-tip radiofrequency catheter ablation (RFCA). We studied the feasibility of temperature-controlled cooled-tip RFCA in the canine heart.An internally cooled ablation catheter was inserted into the left ventricle. A custom-made radiofrequency (RF) generator capable of controlling the tip-temperature at the preset level by slow increases in the power was used. Temperature-controlled cooled-tip RF applications were performed at a target temperature of 40 degrees C for 90 seconds. Acute study: Intramyocardial temperature was measured at the ablation site in 10 dogs by inserting a fluoroptic probe. Chronic study: Lesion depth and volume were measured in 5 dogs after 3 weeks of survival. In the acute study, no pop or abrupt impedance rise was observed. Maximum intramyocardial temperature was 72.4 + or - 14.4 degrees C at 2-4 mm above the endocardium. No coagulum formation, craters, or intramural charring were observed. Maximum lesion depth was 6.7 + or - 1.5 mm, and lesion volume was 404 + or - 219 mm3. In the chronic study, maximum lesion depth was 5.9 + or - 1.1 mm, and lesion volume was 281 + or - 210 mm(3).Temperature controlled RFCA is feasible with a cooled-tip catheter and an RF generator that slowly increases the RF power until the preset catheter-tip temperature is reached. PMID:20558910

  17. Percutaneously inserted central catheter - infants

    MedlinePlus

    PICC - infants; PQC - infants; Pic line - infants; Per-Q cath - infants ... A percutaneously inserted central catheter (PICC) is a long, very thin, soft plastic tube that is put into a small blood vessel. This article addresses PICCs in ...

  18. Central venous catheter - dressing change

    MedlinePlus

    ... will need: Sterile gloves Cleaning solution A special sponge A special patch, called a Biopatch A clear ... around the catheter. Clean the skin with the sponge and cleaning solution. Air dry after cleaning. Place ...

  19. Peripherally inserted central catheter - flushing

    MedlinePlus

    ... To flush your catheter, you will need: Clean paper towels Saline syringes (clear), and maybe heparin syringes ( ... your fingers before washing. Dry with a clean paper towel. Set up your supplies on a clean ...

  20. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  1. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  2. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  3. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  4. 21 CFR 870.1210 - Continuous flush catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1210 Continuous flush catheter. (a) Identification. A continuous flush catheter is an attachment to a catheter-transducer...

  5. Compensation for Unconstrained Catheter Shaft Motion in Cardiac Catheters

    PubMed Central

    Degirmenci, Alperen; Loschak, Paul M.; Tschabrunn, Cory M.; Anter, Elad; Howe, Robert D.

    2016-01-01

    Cardiac catheterization with ultrasound (US) imaging catheters provides real time US imaging from within the heart, but manually navigating a four degree of freedom (DOF) imaging catheter is difficult and requires extensive training. Existing work has demonstrated robotic catheter steering in constrained bench top environments. Closed-loop control in an unconstrained setting, such as patient vasculature, remains a significant challenge due to friction, backlash, and physiological disturbances. In this paper we present a new method for closed-loop control of the catheter tip that can accurately and robustly steer 4-DOF cardiac catheters and other flexible manipulators despite these effects. The performance of the system is demonstrated in a vasculature phantom and an in vivo porcine animal model. During bench top studies the robotic system converged to the desired US imager pose with sub-millimeter and sub-degree-level accuracy. During animal trials the system achieved 2.0 mm and 0.65° accuracy. Accurate and robust robotic navigation of flexible manipulators will enable enhanced visualization and treatment during procedures. PMID:27525170

  6. Real-time circumferential mapping catheter tracking for motion compensation in atrial fibrillation ablation procedures

    NASA Astrophysics Data System (ADS)

    Brost, Alexander; Bourier, Felix; Wimmer, Andreas; Koch, Martin; Kiraly, Atilla; Liao, Rui; Kurzidim, Klaus; Hornegger, Joachim; Strobel, Norbert

    2012-02-01

    Atrial fibrillation (AFib) has been identified as a major cause of stroke. Radiofrequency catheter ablation has become an increasingly important treatment option, especially when drug therapy fails. Navigation under X-ray can be enhanced by using augmented fluoroscopy. It renders overlay images from pre-operative 3-D data sets which are then fused with X-ray images to provide more details about the underlying soft-tissue anatomy. Unfortunately, these fluoroscopic overlay images are compromised by respiratory and cardiac motion. Various methods to deal with motion have been proposed. To meet clinical demands, they have to be fast. Methods providing a processing frame rate of 3 frames-per-second (fps) are considered suitable for interventional electrophysiology catheter procedures if an acquisition frame rate of 2 fps is used. Unfortunately, when working at a processing rate of 3 fps, the delay until the actual motion compensated image can be displayed is about 300 ms. More recent algorithms can achieve frame rates of up to 20 fps, which reduces the lag to 50 ms. By using a novel approach involving a 3-D catheter model, catheter segmentation and a distance transform, we can speed up motion compensation to 25 fps which results in a display delay of only 40 ms on a standard workstation for medical applications. Our method uses a constrained 2-D/3-D registration to perform catheter tracking, and it obtained a 2-D tracking error of 0.61 mm.

  7. Incorporating a Gaussian model at the catheter tip for improved registration of preoperative surface models

    NASA Astrophysics Data System (ADS)

    Rettmann, M. E.; Holmes, D. R., III; Packer, D. L.; Robb, R. A.

    2011-03-01

    Atrial fibrillation is a common cardiac arrhythmia in which aberrant electrical activity cause the atria to quiver which results in irregular beating of the heart. Catheter ablation therapy is becoming increasingly popular in treating atrial fibrillation, a procedure in which an electrophysiologist guides a catheter into the left atrium and creates radiofrequency lesions to stop the arrhythmia. Typical visualization tools include bi-plane fluoroscopy, 2-D ultrasound, and electroanatomic maps, however, recently there has been increased interest in incorporating preoperative surface models into the procedure. Typical strategies for registration include landmark-based and surface-based methods. Drawbacks of these approaches include difficulty in accurately locating corresponding landmark pairs and the time required to sample surface points with a catheter. In this paper, we describe a new approach which models the catheter tip as a Gaussian kernel and eliminates the need to collect surface points by instead using the stream of continuosly tracked catheter points. We demonstrate the feasibility of this technique with a left atrial phantom model and compare the results with a standard surface based approach.

  8. Direct cooling of the catheter tip increases safety for CMR-guided electrophysiological procedures

    PubMed Central

    2012-01-01

    Background One of the safety concerns when performing electrophysiological (EP) procedures under magnetic resonance (MR) guidance is the risk of passive tissue heating due to the EP catheter being exposed to the radiofrequency (RF) field of the RF transmitting body coil. Ablation procedures that use catheters with irrigated tips are well established therapeutic options for the treatment of cardiac arrhythmias and when used in a modified mode might offer an additional system for suppressing passive catheter heating. Methods A two-step approach was chosen. Firstly, tests on passive catheter heating were performed in a 1.5 T Avanto system (Siemens Healthcare Sector, Erlangen, Germany) using a ASTM Phantom in order to determine a possible maximum temperature rise. Secondly, a phantom was designed for simulation of the interface between blood and the vascular wall. The MR-RF induced temperature rise was simulated by catheter tip heating via a standard ablation generator. Power levels from 1 to 6 W were selected. Ablation duration was 120 s with no tip irrigation during the first 60 s and irrigation at rates from 2 ml/min to 35 ml/min for the remaining 60 s (Biotronik Qiona Pump, Berlin, Germany). The temperature was measured with fluoroscopic sensors (Luxtron, Santa Barbara, CA, USA) at a distance of 0 mm, 2 mm, 4 mm, and 6 mm from the catheter tip. Results A maximum temperature rise of 22.4°C at the catheter tip was documented in the MR scanner. This temperature rise is equivalent to the heating effect of an ablator's power output of 6 W at a contact force of the weight of 90 g (0.883 N). The catheter tip irrigation was able to limit the temperature rise to less than 2°C for the majority of examined power levels, and for all examined power levels the residual temperature rise was less than 8°C. Conclusion Up to a maximum of 22.4°C, the temperature rise at the tissue surface can be entirely suppressed by using the catheter's own irrigation system. The irrigated tip

  9. Measurement of radiofrequency fields

    NASA Astrophysics Data System (ADS)

    Leonowich, J. A.

    1992-05-01

    We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields.

  10. Radiofrequency attenuator and method

    DOEpatents

    Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.; Agrawal, Anoop; Hall, Simon B.

    2009-01-20

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  11. Radiofrequency attenuator and method

    DOEpatents

    Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.; Agrawal, Anoop; Hall, Simon B.

    2009-11-10

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3 C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  12. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1997-03-11

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly has a superconducting metal-ceramic design. The srf window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  13. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, H.L.; Elliott, T.S.

    1998-05-19

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The SRF window assembly has a superconducting metal-ceramic design. The SRF window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the SRF window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator. 11 figs.

  14. Cryoballoon or Radiofrequency Ablation for Paroxysmal Atrial Fibrillation.

    PubMed

    Kuck, Karl-Heinz; Brugada, Josep; Fürnkranz, Alexander; Metzner, Andreas; Ouyang, Feifan; Chun, K R Julian; Elvan, Arif; Arentz, Thomas; Bestehorn, Kurt; Pocock, Stuart J; Albenque, Jean-Paul; Tondo, Claudio

    2016-06-01

    Background Current guidelines recommend pulmonary-vein isolation by means of catheter ablation as treatment for drug-refractory paroxysmal atrial fibrillation. Radiofrequency ablation is the most common method, and cryoballoon ablation is the second most frequently used technology. Methods We conducted a multicenter, randomized trial to determine whether cryoballoon ablation was noninferior to radiofrequency ablation in symptomatic patients with drug-refractory paroxysmal atrial fibrillation. The primary efficacy end point in a time-to-event analysis was the first documented clinical failure (recurrence of atrial fibrillation, occurrence of atrial flutter or atrial tachycardia, use of antiarrhythmic drugs, or repeat ablation) following a 90-day period after the index ablation. The noninferiority margin was prespecified as a hazard ratio of 1.43. The primary safety end point was a composite of death, cerebrovascular events, or serious treatment-related adverse events. Results A total of 762 patients underwent randomization (378 assigned to cryoballoon ablation and 384 assigned to radiofrequency ablation). The mean duration of follow-up was 1.5 years. The primary efficacy end point occurred in 138 patients in the cryoballoon group and in 143 in the radiofrequency group (1-year Kaplan-Meier event rate estimates, 34.6% and 35.9%, respectively; hazard ratio, 0.96; 95% confidence interval [CI], 0.76 to 1.22; P<0.001 for noninferiority). The primary safety end point occurred in 40 patients in the cryoballoon group and in 51 patients in the radiofrequency group (1-year Kaplan-Meier event rate estimates, 10.2% and 12.8%, respectively; hazard ratio, 0.78; 95% CI, 0.52 to 1.18; P=0.24). Conclusions In this randomized trial, cryoballoon ablation was noninferior to radiofrequency ablation with respect to efficacy for the treatment of patients with drug-refractory paroxysmal atrial fibrillation, and there was no significant difference between the two methods with regard to

  15. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... This generic type of device includes the suprapubic catheter and tube, Malecot catheter, catheter punch... (performance standards). (2) Class I for the catheter punch instrument, nondisposable cannula and trocar,...

  16. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... This generic type of device includes the suprapubic catheter and tube, Malecot catheter, catheter punch... (performance standards). (2) Class I for the catheter punch instrument, nondisposable cannula and trocar,...

  17. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... This generic type of device includes the suprapubic catheter and tube, Malecot catheter, catheter punch... (performance standards). (2) Class I for the catheter punch instrument, nondisposable cannula and trocar,...

  18. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... This generic type of device includes the suprapubic catheter and tube, Malecot catheter, catheter punch... (performance standards). (2) Class I for the catheter punch instrument, nondisposable cannula and trocar,...

  19. Catheter-based photoacoustic endoscope

    NASA Astrophysics Data System (ADS)

    Yang, Joon-Mo; Li, Chiye; Chen, Ruimin; Zhou, Qifa; Shung, K. Kirk; Wang, Lihong V.

    2014-06-01

    We report a flexible shaft-based mechanical scanning photoacoustic endoscopy (PAE) system that can be potentially used for imaging the human gastrointestinal tract via the instrument channel of a clinical video endoscope. The development of such a catheter endoscope has been an important challenge to realize the technique's benefits in clinical settings. We successfully implemented a prototype PAE system that has a 3.2-mm diameter and 2.5-m long catheter section. As the instrument's flexible shaft and scanning tip are fully encapsulated in a plastic catheter, it easily fits within the 3.7-mm diameter instrument channel of a clinical video endoscope. Here, we demonstrate the intra-instrument channel workability and in vivo animal imaging capability of the PAE system.

  20. Per-catheter ASD closure.

    PubMed

    Latson, L A

    1998-01-01

    Per-catheter devices for atrial septal defect (ASD) closure have been evolving since 1974. The four major devices available for use on a limited basis in early 1997 are reviewed. These include (in alphabetical order) the Angel Wing device, the ASDOS device, the Buttoned device, and the CardioSeal device (successor to the Clamshell). Sufficient data have been collected to indicate that transcatheter ASD closure is a viable alternative to surgery in selected patients. The advantages of the concept of per-catheter closure over surgical closure should lead to the continued development of devices and techniques for per-catheter treatment of ASD and other septal defects in the years to come. PMID:9396853

  1. Switches to English during French Service Encounters: Relationships with L2 French Speakers' Willingness to Communicate and Motivation

    ERIC Educational Resources Information Center

    McNaughton, Stephanie; McDonough, Kim

    2015-01-01

    This exploratory study investigated second language (L2) French speakers' service encounters in the multilingual setting of Montreal, specifically whether switches to English during French service encounters were related to L2 speakers' willingness to communicate or motivation. Over a two-week period, 17 French L2 speakers in Montreal submitted…

  2. On the Role of Linguistic Contextual Factors for Morphosyntactic Stabilization in High-Level L2 French

    ERIC Educational Resources Information Center

    Bartning, Inge; Lundell, Fanny Forsberg; Hancock, Victorine

    2012-01-01

    The purpose of this article is to offer contextual linguistic explanations for morphosyntactic deviances (MSDs) in high-level second language (L2) French (30 nonnative speakers vs. 10 native speakers). It is hypothesized that the distribution of formulaic sequences (FSs) and the complexity of information structure will influence the occurrence of…

  3. Hemodialysis Catheter Care: Identifying Best Cleansing Agents.

    PubMed

    Stupak, Deborah M; Trubilla, Jennifer A; Groller, Susann R

    2016-01-01

    In an attempt to create a standardized resource for cleansing both non-tunneled and tunneled hemodialysis catheters, it was discovered that all disinfectants are not compatible with all catheters. This article describes the process used to identify best practices for hemodialysis catheter care and steps taken to standardize practice throughout a hospital network. Standardized evidence-based practice preserves the integrity of catheters while allowing nurses to provide quality care to patients. PMID:27254970

  4. A novel guide catheter enabling intracranial placement.

    PubMed

    Hurley, Michael C; Sherma, Arun K; Surdell, Daniel; Shaibani, Ali; Bendok, Bernard R

    2009-11-15

    We describe use of a novel guide, catheter with a soft and pliable, 6-cm or 12-cm distal segment that enables distal, including intracranial, placement--the Neuron guide catheter (Penumbra, San Leandro, CA)--in the treatment of 11 cases with a range of neuroendovascular lesions. We were able to advance the Neuron guide catheter to the intended level in each case and suffered no complications related to catheter spasm, dissection, thrombosis or thromboembolism. PMID:19670314

  5. 21 CFR 876.5090 - Suprapubic urological catheter and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... This generic type of device includes the suprapubic catheter and tube, Malecot catheter, catheter punch... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Suprapubic urological catheter and accessories... Suprapubic urological catheter and accessories. (a) Identification. A suprapubic urological catheter...

  6. Model-based lasso catheter tracking in monoplane fluoroscopy for 3D breathing motion compensation during EP procedures

    NASA Astrophysics Data System (ADS)

    Liao, Rui

    2010-02-01

    Radio-frequency catheter ablation (RFCA) of the pulmonary veins (PVs) attached to the left atrium (LA) is usually carried out under fluoroscopy guidance. Overlay of detailed anatomical structures via 3-D CT and/or MR volumes onto the fluoroscopy helps visualization and navigation in electrophysiology procedures (EP). Unfortunately, respiratory motion may impair the utility of static overlay of the volume with fluoroscopy for catheter navigation. In this paper, we propose a B-spline based method for tracking the circumferential catheter (lasso catheter) in monoplane fluoroscopy. The tracked motion can be used for the estimation of the 3-D trajectory of breathing motion and for subsequent motion compensation. A lasso catheter is typically used during EP procedures and is pushed against the ostia of the PVs to be ablated. Hence this method does not require additional instruments, and achieves motion estimation right at the site of ablation. The performance of the proposed tracking algorithm was evaluated on 340 monoplane frames with an average error of 0.68 +/- 0.36 mms. Our contributions in this work are twofold. First and foremost, we show how to design an effective, practical, and workflow-friendly 3-D motion compensation scheme for EP procedures in a monoplane setup. In addition, we develop an efficient and accurate method for model-based tracking of the circumferential lasso catheter in the low-dose EP fluoroscopy.

  7. Biplanar Radiofrequency Coil Design

    NASA Astrophysics Data System (ADS)

    Roberts, D. A.; Insko, E. K.; Bolinger, L.; Leigh, J. S.

    A novel geometry for radiofrequency coil design is described. In this geometry, longitudinal wires of the coil lie on two parallel planes. The currents in the wires of one plane run in the direction opposite to those of the other plane. An analytic solution is provided for the field produced by infinite surface currents running in the biplanar geometry. For the case of discrete wires, computer-generated field maps imply that the homogeneity and sensitivity of the biplanar design are superior to those of a saddle coil, but worse than those obtained in an equivalent discrete cosine or birdcage coil design. Optimization of this coil design was performed using computer simulations. The measured B1 map of an optimized, single-tuned biplanar coil compares favorably to that of an equivalent discrete cosine coil, demonstrating excellent homogeneity in the central region of the coil. A 30 × 24 × 40 cm biplanar coil has been coupled to a 1.5 T imaging system. Images of the human abdomen generated with this coil demonstrate a high degree of homogeneity across nearly all of the sensitive region of the coil.

  8. Measurement of radiofrequency fields

    SciTech Connect

    Leonowich, J.A.

    1992-05-01

    We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs.

  9. Superconductive radiofrequency window assembly

    DOEpatents

    Phillips, Harry Lawrence; Elliott, Thomas S.

    1998-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  10. Superconducting radiofrequency window assembly

    DOEpatents

    Phillips, Harry L.; Elliott, Thomas S.

    1997-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  11. Cytometric Catheter for Neurosurgical Applications

    SciTech Connect

    Evans III, Boyd Mccutchen; Allison, Stephen W; Fillmore, Helen; Broaddus, William C; Dyer, Rachel L; Gillies, George

    2010-01-01

    Implantation of neural progenitor cells into the central nervous system has attracted strong interest for treatment of a variety of pathologies. For example, the replacement of dopamine-producing (DA) neural cells in the brain appears promising for the treatment of patients affected by Parkinson's disease. Previous studies of cell-replacement strategies have shown that less than 90% of implanted cells survive longer than 24 - 48 hours following the implantation procedure. However, it is unknown if these cells were viable upon delivery, or if they were affected by other factors such as brain pathology or an immune response. An instrumented cell-delivery catheter has been developed to assist in answering these questions by facilitating quantification and monitoring of the viability of the cells delivered. The catheter uses a fiber optic probe to perform flourescence-based cytometric measurments on cells exiting the port at the catheter tip. The current implementation of this design is on a 3.2 mm diameter catheter with 245 micrometer diameter optical fibers. Results of fluorescence testing data are presented and show that the device can characterize the quantity of cell densities ranging from 60,000 cells/ml to 600,000 cells/ml with a coefficient of determination of 0.93.

  12. Patency and Complications of Translumbar Dialysis Catheters.

    PubMed

    Liu, Fanna; Bennett, Stacy; Arrigain, Susana; Schold, Jesse; Heyka, Robert; McLennan, Gordon; Navaneethan, Sankar D

    2015-01-01

    Translumbar tunneled dialysis catheter (TLDC) is a temporary dialysis access for patients exhausted traditional access for dialysis. While few small studies reported successes with TLDC, additional studies are warranted to understand the short- and long-term patency and safety of TLDC. We conducted a retrospective analysis of adult patients who received TLDC for hemodialysis access from June 2006 to June 2013. Patient demographics, comorbid conditions, dialysis details, catheter insertion procedures and associated complications, catheter patency, and patient survival data were collected. Catheter patency was studied using Kaplan-Meier curve; catheter functionality was assessed with catheter intervals and catheter-related complications were used to estimate catheter safety. There were 84 TLDCs inserted in 28 patients with 28 primary insertions and 56 exchanges. All TLDC insertions were technically successful with good blood flow during dialysis (>300 ml/minute) and no immediate complications (major bleeding or clotting) were noted. The median number of days in place for initial catheter, secondary catheter, and total catheter were 65, 84, and 244 respectively. The catheter patency rate at 3, 6, and 12 months were 43%, 25%, and 7% respectively. The main complications were poor blood flow (40%) and catheter-related infection (36%), which led to 30.8% and 35.9% catheter removal, respectively. After translumbar catheter, 42.8% of the patients were successfully converted to another vascular access or peritoneal dialysis. This study data suggest that TLDC might serve as a safe, alternate access for dialysis patients in short-term who have exhausted conventional vascular access. PMID:25800550

  13. Minimizing the complications associated with migrating catheters.

    PubMed

    Billington, A; Crane, C; Jownally, S; Kirkwood, L; Roodhouse, A

    2008-11-01

    This article seeks to explore the clinical practice of urinary catheter fixation. Traditionally, this area of practice has been neglected and nurses are familiar with tension lesions and dermal problems associated with inappropriate or incorrect urinary catheter fixation. A novel solution to this problem is a catheter fixation device. This device secures the catheter safely, making clinical practice safer and the experience of catheterization more tolerable for the patient. An example of a urinary catheter fixation device available in the UK is Bard's StatLock. PMID:18981965

  14. Reduction of Fluoroscopy Time and Radiation Dosage During Catheter Ablation for Atrial Fibrillation

    PubMed Central

    Aldhoon, Bashar; Kautzner, Josef

    2016-01-01

    Radiofrequency catheter ablation has become the treatment of choice for atrial fibrillation (AF) that does not respond to antiarrhythmic drug therapy. During the procedure, fluoroscopy imaging is still considered essential to visualise catheters in real-time. However, radiation is often ignored by physicians since it is invisible and the long-term risks are underestimated. In this respect, it must be emphasised that radiation exposure has various potentially harmful effects, such as acute skin injury, malignancies and genetic disease, both to patients and physicians. For this reason, every electrophysiologist should be aware of the problem and should learn how to decrease radiation exposure by both changing the setting of the system and using complementary imaging technologies. In this review, we aim to discuss the basics of X-ray exposure and suggest practical instructions for how to reduce radiation dosage during AF ablation procedures. PMID:27617094

  15. Three-dimensional electroanatomic mapping systems in catheter ablation of atrial fibrillation.

    PubMed

    Lo, Li-Wei; Chen, Shih-Ann

    2010-01-01

    Atrial fibrillation (AF) is the most common tachyarrhythmia, with a prevalence of 5% in people over the age of 65. Catheter ablation of AF has emerged as an important management choice for drug-refractory symptomatic paroxysmal or persistent AF. Three-dimensional (3D) electroanatomic mapping systems were introduced into catheter ablation of AF more than a decade ago. The 3D tool has the benefit of reducing the radiation exposure time, as well as voltage and fractionation mapping in order to identify the critical substrate during the ablation, prevent the formation of gaps, guide the ablation of post-ablation atrial tachycardia or flutter, and integrate images to improve the safety and long-term success rate. The 3D systems successfully enable safe and tailored radiofrequency ablation of AF in individual patients. (Circ J 2010; 74: 18 - 23). PMID:19920357

  16. Light modulated electron beam driven radiofrequency emitter

    DOEpatents

    Wilson, M.T.; Tallerico, P.J.

    1979-10-10

    The disclosure relates to a light modulated electron beam-driven radiofrequency emitter. Pulses of light impinge on a photoemissive device which generates an electron beam having the pulse characteristics of the light. The electron beam is accelerated through a radiofrequency resonator which produces radiofrequency emission in accordance with the electron, hence, the light pulses.

  17. New-generation radiofrequency technology.

    PubMed

    Krueger, Nils; Sadick, Neil S

    2013-01-01

    Radiofrequency (RF) technology has become a standard treatment in aesthetic medicine with many indications due to its versatility, efficacy, and safety. It is used worldwide for cellulite reduction; acne scar revision; and treatment of hypertrophic scars and keloids, rosacea, and inflammatory acne in all skin types. However, the most common indication for RF technology is the nonablative tightening of tissue to improve skin laxity and reduce wrinkles. Radiofrequency devices are classified as unipolar, bipolar, or multipolar depending on the number of electrodes used. Additional modalities include fractional RF; sublative RF; phase-controlled RF; and combination RF therapies that apply light, massage, or pulsed electromagnetic fields (PEMFs). This article reviews studies and case series on these devices. Radiofrequency technology for aesthetic medicine has seen rapid advancements since it was used for skin tightening in 2003. Future developments will continue to keep RF technology at the forefront of the dermatologist's armamentarium for skin tightening and rejuvenation. PMID:23461058

  18. Cardiac ablation catheter guidance by means of a single equivalent moving dipole inverse algorithm

    PubMed Central

    Lee, Kichang; Lv, Wener; Ter-Ovanesyan, Evgeny; Barley, Maya E.; Voysey, Graham E.; Galea, Anna; Hirschman, Gordon; LeRoy, Kristen; Marini, Robert P.; Barrett, Conor; Armoundas, Antonis A.; Cohen, Richard J.

    2015-01-01

    We developed and evaluated a novel system for guiding radio-frequency catheter ablation therapy of ventricular tachycardia. This guidance system employs an Inverse Solution Guidance Algorithm (ISGA) utilizing a single equivalent moving dipole (SEMD) localization method. The method and system were evaluated in both a saline-tank phantom model and in-vivo animal (swine) experiments. A catheter with two platinum electrodes spaced 3 mm apart was used as the dipole source in the phantom study. A 40 Hz sinusoidal signal was applied to the electrode pair. In the animal study, four to eight electrodes were sutured onto the right ventricle. These electrodes were connected to a stimulus generator delivering one millisecond duration pacing pulses. Signals were recorded from 64 electrodes, located either on the inner surface of the saline-tank or the body surface of the pig, and then processed by the ISGA to localize the physical or bioelectrical SEMD. In the phantom studies, the guidance algorithm was used to advance a catheter tip to the location of the source dipole. The distance from the final position of the catheter tip to the position of the target dipole was 2.22 ± 0.78 mm in real space and 1.38± 0.78 mm in image space (computational space). The ISGA successfully tracked the locations of electrodes sutured on the ventricular myocardium and the movement of an endocardial catheter placed in the animal’s right ventricle. In conclusion, we successfully demonstrated the feasibility of using a SEMD inverse algorithm to guide a cardiac ablation catheter. PMID:23448231

  19. In vivo intracardiac optical coherence tomography imaging through percutaneous access: toward image-guided radio-frequency ablation

    PubMed Central

    Wang, Hui; Kang, Wei; Carrigan, Thomas; Bishop, Austin; Rosenthal, Noah; Arruda, Mauricio; Rollins, Andrew M.

    2011-01-01

    Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. The purpose of this study is to evaluate the feasibility of using optical coherence tomography (OCT) catheter to image endocardial wall in actively beating hearts through percutaneous access. We reported the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. This is a critical step toward image-guided RFA in a clinical setting. A cone-scanning forward-viewing OCT catheter was advanced into beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardial wall. We are able to acquire high quality OCT images in beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium, and readily evaluate catheter-tissue contact. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA. PMID:22112101

  20. In vivo intracardiac optical coherence tomography imaging through percutaneous access: toward image-guided radio-frequency ablation

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Kang, Wei; Carrigan, Thomas; Bishop, Austin; Rosenthal, Noah; Arruda, Mauricio; Rollins, Andrew M.

    2011-11-01

    Complete catheter-tissue contact and permanent tissue destruction are essential for efficient radio-frequency ablation (RFA) during cardiac arrhythmia treatment. Current methods of monitoring lesion formation are indirect and unreliable. The purpose of this study is to evaluate the feasibility of using optical coherence tomography (OCT) catheter to image endocardial wall in actively beating hearts through percutaneous access. We reported the first in vivo intracardiac OCT imaging through percutaneous access with a thin and flexible OCT catheter. This is a critical step toward image-guided RFA in a clinical setting. A cone-scanning forward-viewing OCT catheter was advanced into beating hearts through percutaneous access in four swine. The OCT catheter was steered by an introducer to touch the endocardial wall. We are able to acquire high quality OCT images in beating hearts, observe the polarization-related artifacts induced by the birefringence of myocardium, and readily evaluate catheter-tissue contact. The observations indicate that OCT could be a promising technique for in vivo guidance of RFA.

  1. Catheter ablation of Wolff-Parkinson-White syndrome associated with congenital absence of inferior vena cava.

    PubMed

    Inama, G; Vergara, G; Gramegna, L; Rillo, M; Fuochi, C; Furlanello, F

    1998-09-01

    In the present report we describe a patient (a 36-year-old woman with 15 year history of supraventricular tachyarrhythmias) with congenital absence of inferior vena cava (IVC) revealed during radiofrequency (RF) catheter ablation procedure for right postero-septal Wolff-Parkinson-White syndrome (WPW). For the absence of IVC, the ablation procedure was more difficult, because we had to perform the ablation with the catheters (the ablator catheter and the coronary sinus catheter) introduced both through the superior vena cava. The application of RF energy (35 Watt for 60 seconds) at successful site abolished accessory pathway conduction. The following day was performed the venous angiography, showing the absence of the IVC and a venous return via paravertebral venous plexus to the azygous vein and superior vena cava into the right atrium. Computer tomography confirmed the absence of the IVC with azygous continuation. The drainage via the azygous system modified the radiological image on chest roentgenogram of the right mediastinal silhouette. During cardiogenesis fusion of the IVC and organisation of the heart occur between the 33rd to 40th embryonic days. It is therefore possible that some unknown teratogenic mechanism at this critical period might have caused, in the patient, both the developmental arrest of IVC and failure of regression of atrio-ventricular anatomical and electrical continuity in the right postero-septal region. PMID:9870026

  2. Respiratory motion influence on catheter contact force during radio frequency ablation procedures

    NASA Astrophysics Data System (ADS)

    Koch, Martin; Brost, Alexander; Hornegger, Joachim; Strobel, Norbert

    2013-03-01

    Minimally invasive catheter ablation is a common treatment option for atrial fibrillation. A common treatment strategy is pulmonary vein isolation. In this case, individual ablation points need to be placed around the ostia of the pulmonary veins attached to the left atrium to generate transmural lesions and thereby block electric signals. To achieve a durable transmural lesion, the tip of the catheter has to be stable with a sufficient tissue contact during radio-frequency ablation. Besides the steerable interface operated by the physician, the movement of the catheter is also influenced by the heart and breathing motion - particularly during ablation. In this paper we investigate the influence of breathing motion on different areas of the endocardium during radio frequency ablation. To this end, we analyze the frequency spectrum of the continuous catheter contact force to identify areas with increased breathing motion using a classification method. This approach has been applied to clinical patient data acquired during three pulmonary vein isolation procedures. Initial findings show that motion due to respiration is more pronounced at the roof and around the right pulmonary veins.

  3. [RADIOFREQUENCY ABLATION FOR THE TREATMENT OF VARICOSE VEINS].

    PubMed

    Sugiyama, Satoru; Miyade, Yoshio; Inaki, Yasuhiko

    2015-05-01

    Significant advances in the endovenous technique for treating incompetent saphenous veins could change the surgical strategy in patients with varicose veins. Radiofrequency ablation (RFA) was approved as a new technique for the treatment of varicose veins in Japan in June 2014. In RFA, the ablation temperature is controlled by a sensor at the upper end of the catheter. The vein wall is heated with stable conductive power of 120 degrees C, resulting in endothelial denudation. The RFA method was approved in 1998 in Europe and in 1999 in the USA. The ClosurePLUS catheter was developed in 2003 and ClosureFAST in 2006. High occlusion rates and lower postoperative complication rates were reported with ClosureFAST than with ClosurePLUS. It is expected that this new ablation technique will control saphenous vein reflux with less pain and less ecchymosis after surgery. The treatment of varicose veins is less invasive with RFA devices and will become widely accepted as an alternative to conventional surgery for varicose veins in Japan. PMID:26281655

  4. Calcium phosphate in catheter encrustation.

    PubMed

    Cox, A J; Harries, J E; Hukins, D W; Kennedy, A P; Sutton, T M

    1987-02-01

    Encrusted catheters from nine female patients were the source of samples of deposits which were examined by X-ray diffraction, atomic absorption spectroscopy, infra-red spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy. In eight samples the only crystalline phase which could be clearly distinguished by X-ray diffraction was ammonium magnesium orthophosphate hexahydrate, NH4MgPO4 X 6H2O, which occurs naturally as the mineral struvite. However, atomic absorption spectroscopy revealed an appreciable concentration of calcium in all samples. Calcium phosphates have previously been detected in catheter deposits. Infra-red and EXAFS spectra were consistent with the calcium phosphate being present as a poorly crystalline hydroxyapatite. Thus the deposits appear to consist of a mixture of crystalline struvite and a form of hydroxyapatite which is not fully crystalline. PMID:3030487

  5. Intraductal radiofrequency ablation of tumour ingrowth into an uncovered metal stent used for inoperable cholangiocarcinoma.

    PubMed

    Lui, K L; Li, K K

    2013-12-01

    A 91-year-old woman diagnosed to have an inoperable cholangiocarcinoma had an uncovered metal stent inserted for palliative drainage. About 1.5 years later, tumour ingrowth into the metal stent caused cholangitis. Intraductal radiofrequency ablation was applied to create local coagulative tumour necrosis and the necrotic tissue was removed via a balloon catheter. A plastic stent was inserted to empirically treat any ensuing potential bile duct injury. The patient was discharged without complication with good palliative drainage. Intraductal radiofrequency ablation is a new technique for the treatment of metal stent occlusion due to tumour ingrowths. This is the first case report of this relatively safe and feasible new technique for the treatment of tumour ingrowth into a metal stent used as palliation for malignant biliary obstruction. PMID:24310661

  6. Optimization of dialysis catheter function.

    PubMed

    Gallieni, Maurizio; Giordano, Antonino; Rossi, Umberto; Cariati, Maurizio

    2016-03-01

    Central venous catheters (CVCs) are essential in the management of hemodialysis patients, but they also carry unintended negative consequences and in particular thrombosis and infection, adversely affecting patient morbidity and mortality. This review will focus on the etiology, prevention, and management of CVC-related dysfunction, which is mainly associated with inadequate blood flow. CVC dysfunction is a major cause of inadequate depuration. Thrombus, intraluminal and extrinsic, as well as fibrous connective tissue sheath (traditionally indicated as fibrin sheath) formation play a central role in establishing CVC dysfunction. Thrombolysis with urokinase or recombinant tissue plasminogen activator (rTPA) can be undertaken in the dialysis unit, restoring adequate blood flow in most patients, preserving the existing catheter, and avoiding an interventional procedure. If thrombolytics fail, mainly because of the presence of fibrous connective tissue sheath, catheter exchange with fibrin sheath disruption may be successful and preserve the venous access site. Prevention of CVC dysfunction is important for containing costly pharmacologic and interventional treatments, which also affect patients' quality of life. Prevention is based on the use of anticoagulant and/or thrombolytic CVC locks, which are only partially effective. Chronic oral anticoagulation with warfarin has also been proposed, but its use for this indication is controversial and its overall risk-benefit profile has not been clearly established. PMID:26951903

  7. Central vascular catheters and infections.

    PubMed

    Dioni, Elisabetta; Franceschini, Renata; Marzollo, Roberto; Oprandi, Daniela; Chirico, Gaetano

    2014-03-01

    Newborn infants in critical conditions require a permanent intra-venous line to allow for the administration of fluids, parenteral nutrition and drugs. The use of central venous catheters, however, is associated with an increased risk of infections, leading to prolongation of length of stay and higher hospitalization costs, particularly in extremely preterm infants. Dwell time is a significant factor for complications, with a predicted risk of catheter related infections of about 4 per 1000 catheter-days. To reduce the incidence of complications, several requirements must be met, including adequate staff and resources to provide education, training, and quality improvement programs, within a culture of communication and teamwork. Rigorous reporting schedule on line care and the implementation of unique bundle elements, the use of health care failure mode and effect analysis, the judicious use of antibiotics through an antimicrobial stewardship strategy, the application of specific antifungal prophylaxis are among the most effective interventions, while the addition of heparin to parenteral solution, or the use of antibiotic plus heparin lock therapy are under evaluation. Nursing assistance plays a fundamental role in managing central venous lines and in reducing or preventing the incidence of infection, by the application of several complex professional strategies. PMID:24709460

  8. JAG Tearing Technique with Radiofrequency Guide Wire for Aortic Fenestration in Thoracic Endovascular Aneurysm Repair

    SciTech Connect

    Ricci, Carmelo; Ceccherini, Claudio Leonini, Sara; Cini, Marco; Vigni, Francesco; Neri, Eugenio; Tucci, Enrico; Benvenuti, Antonio; Tommasino, Giulio; Sassi, Carlo

    2012-02-15

    An innovative approach, the JAG tearing technique, was performed during thoracic endovascular aneurysm repair in a patient with previous surgical replacement of the ascending aorta with a residual uncomplicated type B aortic dissection who developed an aneurysm of the descending thoracic aorta with its lumen divided in two parts by an intimal flap. The proximal landing zone was suitable to place a thoracic stent graft. The distal landing zone was created by cutting the intimal flap in the distal third of the descending thoracic aorta with a radiofrequency guide wire and intravascular ultrasound catheter.

  9. Tensile set behavior of Foley catheter balloons.

    PubMed

    Joseph, R; Ramesh, P; Sivakumar, R

    1999-01-01

    The removal of indwelling urinary balloon catheters from patients is usually associated with many problems. The problems such as balloon deflation failure; encrustations on balloons, eyes, and lumen; and catheter associated infections are widely discussed in the literature. The tensile set exhibited by the catheter balloon material could also play a role and further complicate the removal process. This article addresses this issue by comparing the tensile set behavior of the balloon material from three commercially available Foley catheters. The balloon materials were subjected to aging in synthetic urine at 37 degrees C for 28 days to simulate clinical conditions. The deflation time of catheter balloons aged in similar conditions were also measured. It was found that different brands of catheters exhibited statistically significant differences in their properties. The tensile set data of the aged samples could be correlated with the deflation time of the balloons. The clinical significance of the tensile set is also highlighted. PMID:10029146

  10. Position Control of Motion Compensation Cardiac Catheters.

    PubMed

    Kesner, Samuel B; Howe, Robert D

    2011-07-21

    Robotic catheters have the potential to revolutionize cardiac surgery by enabling minimally invasive structural repairs within the beating heart. This paper presents an actuated catheter system that compensates for the fast motion of cardiac tissue using 3D ultrasound image guidance. We describe the design and operation of the mechanical drive system and catheter module and analyze the catheter performance limitations of friction and backlash in detail. To mitigate these limitations, we propose and evaluate mechanical and control system compensation methods, including inverse and model-based backlash compensation, to improve the system performance. Finally, in vivo results are presented that demonstrate that the catheter can track the cardiac tissue motion with less than 1 mm RMS error. The ultimate goal of this research is to create a fast and dexterous robotic catheter system that can perform surgery on the delicate structures inside of the beating heart. PMID:21874124

  11. Accidental Entrapment of Electrical Mapping Catheter by Chiari's Network in Right Atrium during Catheter Ablation Procedure

    PubMed Central

    Sakamoto, Atsushi; Urushida, Tsuyoshi; Sakakibara, Tomoaki; Sano, Makoto; Suwa, Kenichiro; Saitoh, Takeji; Saotome, Masao; Katoh, Hideki; Satoh, Hiroshi; Hayashi, Hideharu

    2016-01-01

    A 78-year-old male was admitted to our hospital due to frequent palpitation. His electrocardiogram (ECG) presented regular narrow QRS tachycardia with 170 bpm, and catheter ablation was planned. During electroanatomical mapping of the right atrium (RA) with a multiloop mapping catheter, the catheter head was entrapped nearby the ostium of inferior vena cava. Rotation and traction of the catheter failed to detach the catheter head from the RA wall. Exfoliation of connective tissue twined around catheter tip by forceps, which were designed for endomyocardial biopsy, succeeded to retract and remove the catheter. Postprocedural echocardiography and pathologic examination proved the existence of Chiari's network. The handling of complex catheters in the RA has a potential risk of entrapment with Chiari's network. PMID:27366332

  12. Translumbar placement of paired hemodialysis catheters (Tesio Catheters) and follow-up in 10 patients

    SciTech Connect

    Biswal, Rajiv; Nosher, John L.; Siegel, Randall L.; Bodner, Leonard J.

    2000-01-15

    For lack of other suitable access, 10 consecutive patients received paired hemodialysis catheters for long-term hemodialysis using a translumbar approach to the inferior vena cava (IVC). All attempts were successful. Five paired catheters were placed using the single-puncture technique, and five using the dual-puncture technique. Catheters were in place for a total of 2252 catheter days. The average duration of catheter placement was 250 days (range 30-580 days). All catheters were functioning up to the time the study was completed or the patient died. The most common complication was partial dislodgment of the catheter in 3 of 23 catheters (13%), all occurring in obese patients. One episode of retroperitoneal hemorrhage was noted in a patient having the single-access technique. There were no episodes of infection or IVC thrombosis.

  13. Efficacy comparison between cryoablation and radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter: a meta-analysis.

    PubMed

    Chen, Yi-He; Lin, Hui; Xie, Cheng-Long; Zhang, Xiao-Ting; Li, Yi-Gang

    2015-01-01

    We perform this meta-analysis to compare the efficacy and safety of cryoablation versus radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter. By searching EMBASE, MEDLINE, PubMed and Cochrane electronic databases from March 1986 to September 2014, 7 randomized clinical trials were included. Acute (risk ratio[RR]: 0.93; P = 0.14) and long-term (RR: 0.94; P = 0.08) success rate were slightly lower in cryoablation group than in radiofrequency ablation group, but the difference was not statistically significant. Additionally, the fluoroscopy time was nonsignificantly reduced (weighted mean difference[WMD]: -2.83; P = 0.29), whereas procedure time was significantly longer (WMD: 25.95; P = 0.01) in cryoablation group compared with radiofrequency ablation group. Furthermore, Pain perception during the catheter ablation was substantially less in cryoablation group than in radiofrequency ablation group (standardized mean difference[SMD]: -2.36; P < 0.00001). Thus, our meta-analysis demonstrated that cryoablation and radiofrequency ablation produce comparable acute and long-term success rate for patients with cavotricuspid valve isthmus dependent atrial flutter. Meanwhile, cryoablation ablation tends to reduce the fluoroscopy time and significantly reduce pain perception in cost of significantly prolonged procedure time. PMID:26039980

  14. Efficacy comparison between cryoablation and radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter: a meta-analysis

    NASA Astrophysics Data System (ADS)

    Chen, Yi-He; Lin, Hui; Xie, Cheng-Long; Zhang, Xiao-Ting; Li, Yi-Gang

    2015-06-01

    We perform this meta-analysis to compare the efficacy and safety of cryoablation versus radiofrequency ablation for patients with cavotricuspid valve isthmus dependent atrial flutter. By searching EMBASE, MEDLINE, PubMed and Cochrane electronic databases from March 1986 to September 2014, 7 randomized clinical trials were included. Acute (risk ratio[RR]: 0.93; P = 0.14) and long-term (RR: 0.94; P = 0.08) success rate were slightly lower in cryoablation group than in radiofrequency ablation group, but the difference was not statistically significant. Additionally, the fluoroscopy time was nonsignificantly reduced (weighted mean difference[WMD]: -2.83 P = 0.29), whereas procedure time was significantly longer (WMD: 25.95; P = 0.01) in cryoablation group compared with radiofrequency ablation group. Furthermore, Pain perception during the catheter ablation was substantially less in cryoabaltion group than in radiofrequency ablation group (standardized mean difference[SMD]: -2.36 P < 0.00001). Thus, our meta-analysis demonstrated that cryoablation and radiofrequency ablation produce comparable acute and long-term success rate for patients with cavotricuspid valve isthmus dependent atrial flutter. Meanwhile, cryoablation ablation tends to reduce the fluoroscopy time and significantly reduce pain perception in cost of significantly prolonged procedure time.

  15. Orthogonal electrode catheter array for mapping of endocardial focal site of ventricular activation

    SciTech Connect

    Desai, J.M.; Nyo, H.; Vera, Z.; Seibert, J.A.; Vogelsang, P.J. )

    1991-04-01

    Precise location of the endocardial site of origin of ventricular tachycardia may facilitate surgical and catheter ablation of this arrhythmia. The endocardial catheter mapping technique can locate the site of ventricular tachycardia within 4-8 cm2 of the earliest site recorded by the catheter. This report describes an orthogonal electrode catheter array (OECA) for mapping and radiofrequency ablation (RFA) of endocardial focal site of origin of a plunge electrode paced model of ventricular activation in dogs. The OECA is an 8 F five pole catheter with four peripheral electrodes and one central electrode (total surface area 0.8 cm{sup 2}). In eight mongrel dogs, mapping was performed by arbitrarily dividing the left ventricle (LV) into four segments. Each segment was mapped with OECA to find the earliest segment. Bipolar and unipolar electrograms were obtained. The plunge electrode (not visible on fluoroscopy) site was identified by the earliest wave front arrival times of -30 msec or earlier at two or more electrodes (unipolar electrograms) with reference to the earliest recorded surface ECG (I, AVF, and V1). Validation of the proximity of the five electrodes of the OECA to the plunge electrode was performed by digital radiography and RFA. Pathological examination was performed to document the proximity of the OECA to the plunge electrode and also for the width, depth, and microscopic changes of the ablation. To find the segment with the earliest LV activation a total of 10 {plus minus} 3 (mean {plus minus} SD) positions were mapped. Mean arrival times at the two earlier electrodes were -39 {plus minus} 4 msec and -35 {plus minus} 3 msec. Digital radiography showed the plunge electrode to be within the area covered by all five electrodes in all eight dogs. The plunge electrode was within 1 cm2 area of the region of RFA in all eight dogs.

  16. 3D model-based catheter tracking for motion compensation in EP procedures

    NASA Astrophysics Data System (ADS)

    Brost, Alexander; Liao, Rui; Hornegger, Joachim; Strobel, Norbert

    2010-02-01

    Atrial fibrillation is the most common sustained heart arrhythmia and a leading cause of stroke. Its treatment by radio-frequency catheter ablation, performed using fluoroscopic image guidance, is gaining increasingly more importance. Two-dimensional fluoroscopic navigation can take advantage of overlay images derived from pre-operative 3-D data to add anatomical details otherwise not visible under X-ray. Unfortunately, respiratory motion may impair the utility of these static overlay images for catheter navigation. We developed an approach for image-based 3-D motion compensation as a solution to this problem. A bi-plane C-arm system is used to take X-ray images of a special circumferential mapping catheter from two directions. In the first step of the method, a 3-D model of the device is reconstructed. Three-dimensional respiratory motion at the site of ablation is then estimated by tracking the reconstructed catheter model in 3-D. This step involves bi-plane fluoroscopy and 2-D/3-D registration. Phantom data and clinical data were used to assess our model-based catheter tracking method. Experiments involving a moving heart phantom yielded an average 2-D tracking error of 1.4 mm and an average 3-D tracking error of 1.1 mm. Our evaluation of clinical data sets comprised 469 bi-plane fluoroscopy frames (938 monoplane fluoroscopy frames). We observed an average 2-D tracking error of 1.0 mm +/- 0.4 mm and an average 3-D tracking error of 0.8 mm +/- 0.5 mm. These results demonstrate that model-based motion-compensation based on 2-D/3-D registration is both feasible and accurate.

  17. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  18. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  19. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  20. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  1. 21 CFR 870.1200 - Diagnostic intravascular catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters,...

  2. Phrenic Nerve Injury After Catheter Ablation of Atrial Fibrillation

    PubMed Central

    Sacher, Frederic; Jais, Pierre; Stephenson, Kent; O'Neill, Mark D; Hocini, Meleze; Clementy, Jacques; Stevenson, William G; Haissaguerre, Michel

    2007-01-01

    Phrenic Nerve Injury (PNI) has been well studied by cardiac surgeons. More recently it has been recognized as a potential complication of catheter ablation with a prevalence of 0.11 to 0.48 % after atrial fibrillation (AF) ablation. This review will focus on PNI after AF ablation Anatomical studies have shown a close relationship between the right phrenic nerve and it's proximity to the superior vena cava (SVC), and the antero-inferior part of the right superior pulmonary vein (RSPV). In addition, the proximity of the left phrenic nerve to the left atrial appendage has been well established. Independent of the type of ablation catheter (4mm, 8 mm, irrigated tip, balloon) or energy source used (radiofrequency (RF), ultrasound, cryothermia, and laser); the risk of PNI exists during ablation at the critical areas listed above. Although up to thirty-one percent of patients with PNI after AF ablation remain asymptomatic, dyspnea remain the cardinal symptom and is present in all symptomatic patients. Despite the theoretical risk for significant adverse effect on functional status and quality of life, short-term outcomes from published studies appear favorable with 81% of patients with PNI having a complete recovery after 7 ± 7 months. Conclusion Existing studies have described PNI as an uncommon but avoidable complication in patients undergoing pulmonary vein isolation for AF. Prior to ablation at the SVC, antero-inferior RSPV ostium or the left atrial appendage, pacing should be performed before energy delivery. If phrenic nerve capture is documented, energy delivery should be avoided at this site. Electrophysiologist's vigilance as well as pacing prior to ablation at high risk sites in close proximity to the phrenic nerve are the currently available tools to avoid the complication of PNI. PMID:17235367

  3. Laser welding of balloon catheters

    NASA Astrophysics Data System (ADS)

    Flanagan, Aidan J.

    2003-03-01

    The balloon catheter is one of the principal instruments of non-invasive vascular surgery. It is used most commonly for angioplasty (and in recent years for delivering stents) at a multitude of different sites in the body from small arteries in the heart to the bilary duct. It is composed of a polymer balloon that is attached to a polymer shaft at two points called the distal and proximal bonds. The diverse utility of balloon catheters means a large range of component sizes and materials are used during production; this leads to a complexity of bonding methods and technology. The proximal and distal bonds have been conventionally made using cyanoacrylate or UV curing glue, however with performance requirements of bond strength, flexibility, profile, and manufacturing costs these bonds are increasingly being made by welding using laser, RF, and Hot Jaw methods. This paper describes laser welding of distal and proximal balloon bonds and details beam delivery, bonding mechanisms, bond shaping, laser types, and wavelength choice.

  4. Automated Pointing of Cardiac Imaging Catheters.

    PubMed

    Loschak, Paul M; Brattain, Laura J; Howe, Robert D

    2013-12-31

    Intracardiac echocardiography (ICE) catheters enable high-quality ultrasound imaging within the heart, but their use in guiding procedures is limited due to the difficulty of manually pointing them at structures of interest. This paper presents the design and testing of a catheter steering model for robotic control of commercial ICE catheters. The four actuated degrees of freedom (4-DOF) are two catheter handle knobs to produce bi-directional bending in combination with rotation and translation of the handle. An extra degree of freedom in the system allows the imaging plane (dependent on orientation) to be directed at an object of interest. A closed form solution for forward and inverse kinematics enables control of the catheter tip position and the imaging plane orientation. The proposed algorithms were validated with a robotic test bed using electromagnetic sensor tracking of the catheter tip. The ability to automatically acquire imaging targets in the heart may improve the efficiency and effectiveness of intracardiac catheter interventions by allowing visualization of soft tissue structures that are not visible using standard fluoroscopic guidance. Although the system has been developed and tested for manipulating ICE catheters, the methods described here are applicable to any long thin tendon-driven tool (with single or bi-directional bending) requiring accurate tip position and orientation control. PMID:24683501

  5. Tandem balloon catheter for coronary angioplasty.

    PubMed

    Finci, L; Meier, B; Steffenino, G; Rutishauser, W

    1986-01-01

    The Tandem balloon catheter is a triple lumen steerable catheter for coronary angioplasty with two separately inflatable balloons of different diameters. Indications and results of 26 consecutive patients treated with a Tandem balloon catheter are reviewed. Adequate distal pressure measurements were obtained in 71% of the cases. In ten patients, the Tandem balloon catheter was selected for two stenoses in different segments of the same coronary artery. Angioplasty was successful for all lesions in five and for at least the strategic lesions in five patients (in one only after changing to a single-balloon catheter). In the seven patients with stenoses in two different coronary arteries of various calibers, angioplasty was successful for both vessels in three and for one vessel in four patients. In the six patients with a very tight stenosis, where the Tandem balloon catheter was selected to predilate with the small balloon, the procedure was technically successful in all, but there was a myocardial infarction in one patient. In the three patients with a chronic total occlusion, where the stiffness of the Tandem balloon was the reason for selection, one recanalization was successful. The Tandem balloon catheter provides a handy tool for complex coronary angioplasty. It offers comparable ease in manipulation and pressure transmission and may save time, money, and radiation exposure by avoiding catheter exchanges. PMID:2949848

  6. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nasopharyngeal catheter. 874.4175 Section 874.4175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter....

  7. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nasopharyngeal catheter. 874.4175 Section 874.4175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter....

  8. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nasopharyngeal catheter. 874.4175 Section 874.4175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter....

  9. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nasopharyngeal catheter. 874.4175 Section 874.4175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter....

  10. 21 CFR 874.4175 - Nasopharyngeal catheter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nasopharyngeal catheter. 874.4175 Section 874.4175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Surgical Devices § 874.4175 Nasopharyngeal catheter....

  11. Automated Pointing of Cardiac Imaging Catheters

    PubMed Central

    Loschak, Paul M.; Brattain, Laura J.; Howe, Robert D.

    2013-01-01

    Intracardiac echocardiography (ICE) catheters enable high-quality ultrasound imaging within the heart, but their use in guiding procedures is limited due to the difficulty of manually pointing them at structures of interest. This paper presents the design and testing of a catheter steering model for robotic control of commercial ICE catheters. The four actuated degrees of freedom (4-DOF) are two catheter handle knobs to produce bi-directional bending in combination with rotation and translation of the handle. An extra degree of freedom in the system allows the imaging plane (dependent on orientation) to be directed at an object of interest. A closed form solution for forward and inverse kinematics enables control of the catheter tip position and the imaging plane orientation. The proposed algorithms were validated with a robotic test bed using electromagnetic sensor tracking of the catheter tip. The ability to automatically acquire imaging targets in the heart may improve the efficiency and effectiveness of intracardiac catheter interventions by allowing visualization of soft tissue structures that are not visible using standard fluoroscopic guidance. Although the system has been developed and tested for manipulating ICE catheters, the methods described here are applicable to any long thin tendon-driven tool (with single or bi-directional bending) requiring accurate tip position and orientation control. PMID:24683501

  12. Spontaneous Intravesical Knotting of Urethral Catheter

    PubMed Central

    2011-01-01

    Infant feeding tubes (IFT) have been universally used as urethral catheters in neonates and children for several decades. Though generally a safe procedure, it may cause significant morbidity if the catheter spontaneously knots inside the bladder. We report this complication in three children including a neonate. PMID:22953288

  13. Use of ultrasound guidance to remove entrapped stimulating popliteal catheters

    PubMed Central

    Hulin, James B.; Daniels, Don J.

    2016-01-01

    Peripheral nerve catheters are beneficial for continuous pain relief following surgery or trauma to an extremity. However, spring-loaded peripheral nerve catheters can become uncoiled and entrapped, resulting in difficulty in catheter removal. We present two cases where ultrasound guidance provided significant assistance in the safe removal of entrapped peripheral nerve catheters without neurologic sequelae. One of the catheters was adhered to nearby tissue, and one had become uncoiled and anchored in place by the distal tip. Guidelines for the safe management of entrapped catheters are suggested, including the use of saline injections through the catheter under ultrasound guidance to assist in the evaluation and removal of the catheters. PMID:27034548

  14. In vivo quantitative assessment of catheter patency in rats

    PubMed Central

    Yang, Jun; Maarek, Jean-Michel I; Holschneider, Daniel P

    2014-01-01

    Summary Formation of fibrin sleeves around catheter tips is a central factor in catheter failure during chronic implantation, and such tissue growth can occur despite administration of anticoagulants. We developed a novel method for monitoring catheter patency. This method recognizes the progressive nature of catheter occlusion, and tracks this process over time through measurement of changes in catheter resistance to a standardized 1 mL bolus infusion from a pressurized reservoir. Two indirect measures of catheter patency were used: (a) reservoir residual pressure and (b) reservoir discharge time. This method was applied to the study of catheter patency in rats comparing the effect of catheter material (silastic, polyurethane, Microrenathane™), lock solution (heparin, heparin/dexamethasone) and two different cannulation sites (superior vena cava via the external jugular vein, inferior vena cava via the femoral vein). Our findings reveal that application of flexible smaller-size silastic catheters and a dexamethasone lock solution resulted in prolonged catheter patency. Patency could be maintained over nine weeks with the femoral vein catheters, compared with five weeks with the external jugular vein catheters. The current method for measuring catheter patency provides a useful index for the assessment of tissue growth around the catheter tip. The method also provides an objective and quantitative way of comparing changes in catheter patency for different surgical methods and catheter types. Our method improves on the conventional method of assessing catheter occlusion by judging the ability to aspirate from the catheter. PMID:16004684

  15. Development of Bend Sensor for Catheter Tip

    NASA Astrophysics Data System (ADS)

    Nagano, Yoshitaka; Sano, Akihito; Fujimoto, Hideo

    Recently, a minimally invasive surgery which makes the best use of the catheter has been becoming more popular. In endovascular coil embolization for a cerebral aneurysm, the observation of the catheter's painting phenomenon is very important to execute the appropriate manipulation of the delivery wire and the catheter. In this study, the internal bend sensor which consists of at least two bending enhanced plastic optical fibers was developed in order to measure the curvature of the catheter tip. Consequently, the painting could be more sensitively detected in the neighborhood of the aneurysm. In this paper, the basic characteristics of the developed sensor system are described and its usefulness is confirmed from the comparison of the insertion force of delivery wire and the curvature of catheter tip in the experiment of coil embolization.

  16. Nonoperative replacement of a jejunostomy feeding catheter.

    PubMed

    Stogdill, B J; Page, C P; Pestana, C

    1984-02-01

    Nonoperative replacement of lost or occluded jejunal feeding catheters proved successful in 8 of 11 patients. This technique is recommended as a nonoperative means of replacing a needle catheter jejunostomy when it is accidentally lost or becomes occluded. Adherence to sterile technique and gentle advancement of the guide wire to avoid injury to the bowel are important. Since the technique depends on an established tract between the skin and the bowel, catheter replacement should not be attempted when the feeding catheter is lost or becomes occluded in the immediate postoperative period. In addition, confirmation of catheter patency and intraluminal position with sterile water-soluble contrast medium is critical to the safe use of this technique. PMID:6421183

  17. [The radiofrequency ablation of accessory pathways in 100 consecutive patients with supraventricular tachycardias].

    PubMed

    Colín, L; Kershenovich, S; Iturralde, P; Dan, L; Martínez Ríos, M A; Casanova, M; González Hermosillo, J A

    1993-01-01

    The purpose of this study is to describe the results and the complications of radiofrequency catheter ablation, of accessory pathways in 100 consecutive patients. We had one patient with two pathways. Of the 101 accessory pathways, 56 were overt and 45 concealed. Only 19 patients have had a previous electrophysiology study, in the others, the study and the ablation were performed simultaneously. The location of the accessory pathways were as follows: 61 pathways in the free wall of the left ventricle, 4 in the free wall of the right ventricle, 25 in the left posteroseptal region, 9 in the right posteroseptal region and 2 in the right anteroseptal area. The time required for the diagnostic component of the electrophysiology study, the ablation procedure and the fluoroscopic time was recorded for each patient. Ninety-one of 101 accessory AV connections were successfully ablated (90%). Our success rate for the initial attempt was 87%. We had the opportunity to do a second attempt in only 4 out of 14 patients. The mean time of the procedure, including the electrophysiology test and the ablation was 95.6 %/-55.3 minutes. We have had a recurrence of 9% and 4% of non fatal complications. Radiofrequency catheter ablation can be performed safely and with a high success rate. PMID:8466365

  18. Impact of computed tomography image and contact force technology on catheter ablation for atrial fibrillation

    PubMed Central

    Marai, Ibrahim; Suleiman, Mahmoud; Blich, Miry; Lessick, Jonathan; Abadi, Sobhi; Boulos, Monther

    2016-01-01

    AIM: To investigate the impact of using computed tomography (CT) and contact force (CF) technology on recurrence of atrial tachyarrhythmia after atrial fibrillation (AF) ablation. METHODS: This non-randomized study included 2 groups of patients. All patients had symptomatic recurrent paroxysmal or persistent AF and were treated with at least 1 anti arrhythmic medication or intolerant to medication. The first group included 33 patients who underwent circumferential pulmonary veins isolation (PVI) for AF during 2012 and 2013 guided by CT image integration (Cartomerge, Biosense Webster, Diamond Bar, CA, United States) of left atrium and pulmonary veins into an electroanatomic mapping (EAM) system (CT group) using standard irrigated radiofrequency catheter (ThermoCool, Carto, Biosense Webster, Diamond Bar, CA, United States) or irrigated catheter with integrated CF sensor (Smart Touch, Carto, Biosense Webster, Diamond Bar, CA, United States). The second group included immediately preceding 32 patients who had circumferential PVI by standard irrigated catheter (ThermoCool) using only EAM (Carto) system (EAM group). Linear lesions were performed according to the discretion of operator. RESULTS: Sex, age, and persistent AF were not different between groups. PVI was achieved in all patients in both groups. Linear ablations including cavo-tricuspid isthmus and or roof line ablation were not different between groups. Free of atrial tachyarrhythmia during follow-up of 24 mo was significantly higher among CT group compared to EAM group (81% vs 55%; respectively; P = 0.027). When 11 patients from CT group who had ablation using Smart Touch catheter were excluded, the difference between CT group and EAM became non significant (73% vs 55%; respectively; P = 0.16). Sub analysis of CT group showed that patients who had ablation using Smart Touch catheter tend to be more free of atrial tachyarrhythmia compared to patients who had ablation using standard irrigated catheter during

  19. Radiological Interventions for Correction of Central Venous Port Catheter Migrations

    SciTech Connect

    Gebauer, Bernhard Teichgraeber, Ulf Karl; Podrabsky, Petr; Werk, Michael; Haenninen, Enrique Lopez; Felix, Roland

    2007-07-15

    Purpose. The purpose of this study was to evaluate radiological-interventional central venous port catheter corrections in migrated/malpositioned catheter tips. Materials and Methods. Thirty patients with migrated/malpositioned port catheter tips were included in this retrospective analysis. To visualize the catheter patency a contrast-enhanced port catheter series was performed, followed by transfemoral port catheter correction with various 5-F angiographic catheters (pigtail; Sos Omni), gooseneck snares, or combinations thereof. Results. One patient showed spontaneous reposition of the catheter tip. In 27 of 29 patients (93%), radiological-interventional port catheter correction was successful. In two patients port catheter malposition correction was not possible, because of the inability to catch either the catheter tip or the catheter in its course, possibly due to fibrin sheath formation with attachment of the catheter to the vessel wall. No disconnection or port catheter dysfunction was observed after correction. Conclusions. We conclude that in migrated catheter tips radiological-interventional port catheter correction is a minimally invasive alternative to port extraction and reimplantation. In patients with a fibrin sheath and/or thrombosis port catheter correction is often more challenging.

  20. ATLS: Catheter and tube placement

    NASA Technical Reports Server (NTRS)

    Gosbee, John; Krupa, Debra T.; Pepper, L.; Orsak, Debra

    1991-01-01

    The specific objectives of this experiment are: to evaluate the rack mounted equipment and medical supplies necessary for medical procedures; to evaluate the attachments, mounting points, and inner drawer assemblies for the medical supplies; and to evaluate the procedures for performing medical scenarios. The resources available in the HMF miniracks to accomplish medical scenarios and/or procedures include: medical equipment mounted in the racks; a patch panel with places to attach tubing and catheters; self contained drawers full of critical care medical supplies; and an ALS 'backpack' for deploying supplies. The attachment lines, tubing and associated medical supplies will be deployed and used with the equipment and a patient mannequin. Data collection is provided by direct observations by the inflight experimenters, and analysis of still and video photography.

  1. Catheters for optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Atif, M.; Ullah, H.; Hamza, M. Y.; Ikram, M.

    2011-09-01

    The objective of this review article is to overview technology, clinical evidence, and future applications to date optical coherence tomography (OCT) probes to yield the diagnostic purpose. We have reviewed the designing, construction and working of different categories of OCT probes developed for optical diagnostics having a potential for non invasive and improved detection of different types of cancer as well as other neoplasm. Rotational and balloon catheters, imaging needles and hand-held, linear scanning, multichannel, micro electro mechanical systems (MEMS) technology based, dynamic focusing, forward view imaging, and common path interferometer based probes have been discussed in details. The fiber probes have shown excellent performance for two dimensional and three dimensional higher resolution, cross-sectional imaging of interior and exterior body tissues that can be compared with histopathology to provide the information about the angiogenesis and other lesions in the tissue. The MEMS-technology based probes are found to be more suitable for three dimensional morphological imaging.

  2. Radiofrequency Physics for Minimally Invasive Aesthetic Surgery.

    PubMed

    Levy, Adam S; Grant, Robert T; Rothaus, Kenneth O

    2016-07-01

    Radiofrequency energy has a wide range of medical applications, including noninvasive treatment of wrinkles and body contouring. This technology works by differential heating of skin and soft tissue layers causing dermal remodeling or adipolysis, ultimately leading to observable effects. This article reviews the physics of radiofrequency as applied clinically. PMID:27363769

  3. Catheter associated infections in hemodialysis patients.

    PubMed

    Sanavi, Suzan; Ghods, Ahad; Afshar, Reza

    2007-03-01

    Hemodialysis catheter related infections (HCRI) are one of the major causes of increasing mortality, morbidity and cost of therapy in hemodialysis patients. Prevention of HCRI requires the identification of predisposing risk factors. To determine the frequency of HCRI risk factors, we studied 116 patients (54% male, mean age of 49.5+/-16 years) patients with HCRI between 2003-2004. Forty one percent of the patients were diabetic. There was a history of previous catheter placement and infection in 41% and 32% of patients, respectively. Pathogenic organisms isolated from blood cultures included Staphylococcus-aureus 42%, Coagulase-negative Staphylococci 20%, E. Coli 19%, Enterococci 7%, Streptococcus D 7%, Pseudomonas aeruginosa 4%, and Klebsiella 1%. Bacterial resistance to vancomycin and amikacin was present in 7% and 4% of the cases, respectively. Hemodialysis catheter related blood borne infections comprised 67% of the total blood-borne infections in our hospital. No significant statistical association was found between HCRI and age, gender, diabetes mellitus, serum albumin level <30 g/L, leukocyte count, erythrocyte sedimentation rate, anatomical location of catheter, mean duration of antibiotic therapy, mean catheter duration, frequency of hemodialysis sessions, pathogenic organisms, and history of previous catheter infection. We conclude that the prevalence of pathogenic organisms of HCRI were similar to previous studies. However, bacterial resistance to antibiotics was low. The mean duration of catheter usage was longer than previously reported. PMID:17237890

  4. Consensus for the Treatment of Varicose Vein with Radiofrequency Ablation

    PubMed Central

    Joh, Jin Hyun; Kim, Woo-Shik; Jung, In Mok; Park, Ki-Hyuk; Lee, Taeseung; Kang, Jin Mo

    2014-01-01

    The objective of this paper is to introduce the schematic protocol of radiofrequency (RF) ablation for the treatment of varicose veins. Indication: anatomic or pathophysiologic indication includes venous diameter within 2–20 mm, reflux time ≥0.5 seconds and distance from the skin ≥5 mm or subfascial location. Access: it is recommended to access at or above the knee joint for great saphenous vein and above the mid-calf for small saphenous vein. Catheter placement: the catheter tip should be placed 2.0 cm inferior to the saphenofemoral or saphenopopliteal junction. Endovenous heat-induced thrombosis ≥class III should be treated with low-molecular weight heparin. Tumescent solution: the composition of solution can be variable (e.g., 2% lidocaine 20 mL+500 mL normal saline+bicarbonate 2.5 mL with/without epinephrine). Infiltration can be done from each direction. Ablation: two cycles’ ablation for the first proximal segment of saphenous vein and the segment with the incompetent perforators is recommended. The other segments should be ablated one time. During RF energy delivery, it is recommended to apply external compression. Concomitant procedure: It is recommended to do simultaneously ambulatory phlebectomy. For sclerotherapy, it is recommended to defer at least 2 weeks. Post-procedural management: post-procedural ambulation is encouraged to reduce the thrombotic complications. Compression stocking should be applied for at least 7 days. Minor daily activity is not limited, but strenuous activities should be avoided for 2 weeks. It is suggested to take showers after 24 hours and tub baths, swimming, or soaking in water after 2 weeks. PMID:26217628

  5. Electrophysiological mapping and radiofrequency catheter ablation for ventricular tachycardia in a patient with peripartum cardiomyopathy.

    PubMed

    Tokuda, Michifumi; Stevenson, William G; Nagashima, Koichi; Rubin, David A

    2013-11-01

    A 38-year-old female with prior failed endocardial ablation for ventricular tachycardia (VT) was referred for further treatment. She had been diagnosed with peripartum cardiomyopathy 7 years before and had persistent left ventricular dysfunction with an ejection fraction of 20%. Epicardial voltage mapping showed extensive epicardial scar despite absence of endocardial scar. Five distinct VT morphologies were induced. Ablation was aided by electrogram characteristics, pace mapping, entrainment mapping, and establishing electrical inexcitability along areas of epicardial scar. After epicardial ablation no sustained VT was induced. She had been doing well without VT occurrence but died 1 year later unexpectedly at home. PMID:24102817

  6. Aesthetic Applications of Radiofrequency Devices.

    PubMed

    Sadick, Neil; Rothaus, Kenneth O

    2016-07-01

    Radiofrequency (RF)-based devices are used to improve face and neck laxity, a major feature of aging that until recently could only be addressed with surgery. Although these treatments are not meant to replace surgical procedures, patient satisfaction studies have been consistently high. For physicians offering these skin rejuvenation procedures, it is essential to have intimate knowledge of how the devices work, select appropriate candidates, set realistic expectations, and combine treatments to optimize outcomes. This article discusses the various noninvasive RF technologies currently in use and reviews pertinent clinical studies evaluating their efficacy and safety. PMID:27363770

  7. [Catheter-associated urinary tract infections].

    PubMed

    Liedl, B

    2015-09-01

    In patients with indwelling urethral catheters significant bacteriuria develops within 4 weeks of indwelling time in practically 100% of the cases. Catheter encrustation and obstruction can occur in approximately 40% of patients. Symptomatic ascending urinary tract infections, urethral complications and urolithiasis can occur in significant numbers in the long term. Regular educational and surveillance programs in nursing homes, hospitals and in home care are important to instruct personnel in hygiene procedures, to learn the indications for catheterization, to keep the indwelling time of catheters as short as possible, to detect any complications early and to initiate appropriate diagnostics and therapy by the urologist. PMID:26275988

  8. [Pericardial tamponade due to malpositioned cooling catheter].

    PubMed

    Löwer, C; Niedeggen, A; Janssens, U

    2016-05-01

    The case of a 60-year-old woman who received prehospital cardiopulmonary resuscitation for cardiopulmonary arrest is reported. In the hospital, coronary angiography was performed including percutaneous coronary intervention of the left anterior descending artery and placement of a cooling catheter. After approximately 30 min, severe hypotension progressively developed. Pericardial tamponade was identified and treated by pericardial puncture. Clear fluid was drained. Transesophageal echocardiography detected a perforation of the right atrial roof by the cooling catheter. Open surgery was performed immediately and the catheter was removed. The patient was discharged from the hospital without any further complication 10 days later. PMID:26065384

  9. Percutaneous Intraductal Radiofrequency Ablation is a Safe Treatment for Malignant Biliary Obstruction: Feasibility and Early Results

    SciTech Connect

    Mizandari, Malkhaz; Pai, Madhava Xi Feng; Valek, Vlastimil; Tomas, Andrasina; Quaretti, Pietro; Golfieri, Rita; Mosconi, Cristina; Ao Guokun; Kyriakides, Charis; Dickinson, Robert; Nicholls, Joanna; Habib, Nagy

    2013-06-15

    Purpose. Previous clinical studies have shown the safety and efficacy of this novel radiofrequency ablation catheter when used for endoscopic palliative procedures. We report a retrospective study with the results of first in man percutaneous intraductal radiofrequency ablation in patients with malignant biliary obstruction. Methods. Thirty-nine patients with inoperable malignant biliary obstruction were included. These patients underwent intraductal biliary radiofrequency ablation of their malignant biliary strictures following external biliary decompression with an internal-external biliary drainage. Following ablation, they had a metal stent inserted. Results. Following this intervention, there were no 30-day mortality, hemorrhage, bile duct perforation, bile leak, or pancreatitis. Of the 39 patients, 28 are alive and 10 patients are dead with a median survival of 89.5 (range 14-260) days and median stent patency of 84.5 (range 14-260) days. One patient was lost to follow-up. All but one patient had their stent patent at the time of last follow-up or death. One patient with stent blockage at 42 days postprocedure underwent percutaneous transhepatic drain insertion and restenting. Among the patients who are alive (n = 28) the median stent patency was 92 (range 14-260) days, whereas the patients who died (n = 10) had a median stent patency of 62.5 (range 38-210) days. Conclusions. In this group of patients, it appears that this new approach is feasible and safe. Efficacy remains to be proven in future, randomized, prospective studies.

  10. Retained Urethral Catheter Secondary to Placement in Proximal Ureter

    PubMed Central

    Sharda, Rajan

    2016-01-01

    We present an unusual complication secondary to indwelling urethral catheter placement. Routine catheter placement by the obstetrics team in a postpartum female leads to retention of the catheter and inability of its removal by both the obstetrics and urology teams. Although a retained urinary catheter is relatively common, inability to remove a catheter secondary to placement inadvertently into a ureter is extremely rare. In this paper we will discuss the options in removing a retained catheter and present our case of a retained catheter secondary to placement within the right proximal ureter. PMID:27144050

  11. Dialysis catheter fibrin sheath stripping: a useful technique after failed catheter exchange.

    PubMed

    Mohamad Ali, Af; Uhwut, E; Liew, Sk

    2012-01-01

    Fibrin sheath formation around long-term haemodialysis catheter is a common cause of failed dialysis access. Treatment options include pharmacological and mechanical methods. This paper reports a case of failed dialysis access due to fibrin sheath encasement. Pharmacologic thrombolysis, mechanical disruption using guide wire and catheter exchange had failed to address the issue. Eventually, fibrin sheath stripping using the loop snare technique was able to successfully restore the catheter function. PMID:22970064

  12. Band-selective radiofrequency pulses

    NASA Astrophysics Data System (ADS)

    Geen, Helen; Freeman, Ray

    A theoretical treatment is given of the general problem of designing amplitude-modulated radiofrequency pulses that will excite a specified band of frequencies within a high-resolution NMR spectrum with uniform intensity and phase but with negligible excitation elsewhere. First a trial pulse envelope is defined in terms of a finite Fourier series and its frequency-domain profile calculated through the Bloch equations. The result is compared with the desired target profile to give a multidimensional error surface. The method of simulated annealing is then used to find the global minimum on this surface and the result refined by standard gradient-descent optimization. In this manner, a family of new shaped radio-frequency pulses, known as BURP ( band-selective, uniform response, pure-phase) pulses, has been created. These are of two classes—pulses that excite or invert z magnetization and those that act as general-rotation πr/2 or π pulses irrespective of the initial condition of the nuclear magnetization. It was found convenient to design the latter class as amplitude-modulated time-symmetric pulses. Tables of Fourier coefficients and pulse-shape ordinates are given for practical implementation of BURP pulses, together with the calculated frequency-domain responses and experimental verifications. Examples of the application of band-selective pulses in conventional and multidimensional spectroscopy are given. Pure-phase pulses of this type should also find applications in magnetic resonance imaging where refocusing schemes are undesirable.

  13. Toward guidance of epicardial cardiac radiofrequency ablation therapy using optical coherence tomography

    PubMed Central

    Fleming, Christine P.; Quan, Kara J.; Rollins, Andrew M.

    2010-01-01

    Radiofrequency ablation (RFA) is the standard of care to cure many cardiac arrhythmias. Epicardial ablation for the treatment of ventricular tachycardia has limited success rates due in part to the presence of epicardial fat, which prevents proper rf energy delivery, inadequate contact of ablation catheter with tissue, and increased likelihood of complications with energy delivery in close proximity to coronary vessels. A method to directly visualize the epicardial surface during RFA could potentially provide feedback to reduce complications and titrate rf energy dose by detecting critical structures, assessing probe contact, and confirming energy delivery by visualizing lesion formation. Currently, there is no technology available for direct visualization of the heart surface during epicardial RFA therapy. We demonstrate that optical coherence tomography (OCT) imaging has the potential to fill this unmet need. Spectral domain OCT at 1310 nm is employed to image the epicardial surface of freshly excised swine hearts using a microscope integrated bench-top scanner and a forward imaging catheter probe. OCT image features are observed that clearly distinguish untreated myocardium, ablation lesions, epicardial fat, and coronary vessels, and assess tissue contact with catheter-based imaging. These results support the potential for real-time guidance of epicardial RFA therapy using OCT imaging. PMID:20799788

  14. Toward guidance of epicardial cardiac radiofrequency ablation therapy using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Fleming, Christine P.; Quan, Kara J.; Rollins, Andrew M.

    2010-07-01

    Radiofrequency ablation (RFA) is the standard of care to cure many cardiac arrhythmias. Epicardial ablation for the treatment of ventricular tachycardia has limited success rates due in part to the presence of epicardial fat, which prevents proper rf energy delivery, inadequate contact of ablation catheter with tissue, and increased likelihood of complications with energy delivery in close proximity to coronary vessels. A method to directly visualize the epicardial surface during RFA could potentially provide feedback to reduce complications and titrate rf energy dose by detecting critical structures, assessing probe contact, and confirming energy delivery by visualizing lesion formation. Currently, there is no technology available for direct visualization of the heart surface during epicardial RFA therapy. We demonstrate that optical coherence tomography (OCT) imaging has the potential to fill this unmet need. Spectral domain OCT at 1310 nm is employed to image the epicardial surface of freshly excised swine hearts using a microscope integrated bench-top scanner and a forward imaging catheter probe. OCT image features are observed that clearly distinguish untreated myocardium, ablation lesions, epicardial fat, and coronary vessels, and assess tissue contact with catheter-based imaging. These results support the potential for real-time guidance of epicardial RFA therapy using OCT imaging.

  15. Antimicrobial-impregnated catheters for the prevention of catheter-related bloodstream infections

    PubMed Central

    Lorente, Leonardo

    2016-01-01

    Central venous catheters are commonly used in critically ill patients. Such catheterization may entail mechanical and infectious complications. The interest in catheter-related infection lies in the morbidity, mortality and costs that it involved. Numerous contributions have been made in the prevention of catheter-related infection and the current review focuses on the possible current role of antimicrobial impregnated catheters to reduce catheter-related bloodstream infections (CRBSI). There is evidence that the use of chlorhexidine-silver sulfadiazine (CHSS), rifampicin-minocycline, or rifampicin-miconazol impregnated catheters reduce the incidence of CRBSI and costs. In addition, there are some clinical circumstances associated with higher risk of CRBSI, such as the venous catheter access and the presence of tracheostomy. Current guidelines for the prevention of CRBSI recommended the use of a CHSS or rifampicin-minocycline impregnated catheter in patients whose catheter is expected to remain in place > 5 d and if the CRBSI rate has not decreased after implementation of a comprehensive strategy to reduce it. PMID:27152256

  16. Antimicrobial-impregnated catheters for the prevention of catheter-related bloodstream infections.

    PubMed

    Lorente, Leonardo

    2016-05-01

    Central venous catheters are commonly used in critically ill patients. Such catheterization may entail mechanical and infectious complications. The interest in catheter-related infection lies in the morbidity, mortality and costs that it involved. Numerous contributions have been made in the prevention of catheter-related infection and the current review focuses on the possible current role of antimicrobial impregnated catheters to reduce catheter-related bloodstream infections (CRBSI). There is evidence that the use of chlorhexidine-silver sulfadiazine (CHSS), rifampicin-minocycline, or rifampicin-miconazol impregnated catheters reduce the incidence of CRBSI and costs. In addition, there are some clinical circumstances associated with higher risk of CRBSI, such as the venous catheter access and the presence of tracheostomy. Current guidelines for the prevention of CRBSI recommended the use of a CHSS or rifampicin-minocycline impregnated catheter in patients whose catheter is expected to remain in place > 5 d and if the CRBSI rate has not decreased after implementation of a comprehensive strategy to reduce it. PMID:27152256

  17. Catheter Ablation of Pediatric Focal Atrial Tachycardia: Ten-Year Experience Using Modern Mapping Systems.

    PubMed

    Dieks, Jana-K; Müller, Matthias J; Schneider, Heike E; Krause, Ulrich; Steinmetz, Michael; Paul, Thomas; Kriebel, Thomas

    2016-03-01

    Experience of catheter ablation of pediatric focal atrial tachycardia (FAT) is still limited. There are data which were gathered prior to the introduction of modern 3D mapping and navigation systems into the clinical routine. Accordingly, procedures were associated with significant fluoroscopy and low success rates. The aim of this study was to present clinical and electrophysiological details of catheter ablation of pediatric FAT using modern mapping systems. Since March 2003, 17 consecutive patients <20 years underwent electrophysiological study (EPS) for FAT using the NavX(®) system (n = 7), the non-contact mapping system (n = 6) or the LocaLisa(®) system (n = 4), respectively. Radiofrequency was the primary energy source; cryoablation was performed in selected patients with a focus close to the AV node. In 16 patients, a total number of 19 atrial foci (right-sided n = 13, left-sided n = 6) could be targeted. In the remaining patient, FAT was not present/inducible during EPS. On an intention-to-treat basis, acute success was achieved in 14/16 patients (87.5 %) with a median number of 11 (1-31) energy applications. Ablation was unsuccessful in two patients due to an epicardial location of a right atrial focus (n = 1) and a focus close to the His bundle (n = 1), respectively. Median procedure time was 210 (84-332) min, and median fluoroscopy time was 13.1 (4.5-22.5) min. In pediatric patients with FAT, 3D mapping and catheter ablation provided improved clinical quality of care. Catheter ablation may be considered early in the course of treatment of this tachyarrhythmia in symptomatic patients. PMID:26538211

  18. RF HEATING OF MRI-ASSISTED CATHETER STEERING COILS FOR INTERVENTIONAL MRI

    PubMed Central

    Settecase, Fabio; Hetts, Steven W.; Martin, Alastair J.; Roberts, Timothy P. L.; Bernhardt, Anthony F.; Evans, Lee; Malba, Vincent; Saeed, Maythem; Arenson, Ronald L.; Kucharzyk, Walter; Wilson, Mark W.

    2010-01-01

    RATIONALE AND OBJECTIVES To assess magnetic resonance imaging (MRI) radiofrequency (RF) related heating of conductive wire coils used in magnetically steerable endovascular catheters. MATERIALS AND METHODS A 3-axis microcoil was fabricated onto a 1.8 Fr catheter tip. In vitro testing was performed in a 1.5 T MRI system using an agarose gel filled vessel phantom, a transmit/receive body RF coil and a steady state free precession (SSFP) pulse sequence, and a fluoroptic thermometry system. Temperature was measured without simulated blood flow at varying distances from magnet isocenter and varying flip angles. Additional experiments were performed with laser-lithographed single-axis microcoil-tipped microcatheters in air and in a saline bath with varied grounding of the microcoil wires. Preliminary in vivo evaluation of RF heating was performed in pigs at 1.5 T with coil-tipped catheters in various positions in the common carotid arteries with SSFP pulse sequence on and off, and under physiologic flow and zero flow conditions. RESULTS In tissue-mimicking agarose gel, RF heating resulted in a maximal temperature increase of 0.35°C after 15 minutes of imaging, 15 cm from magnet isocenter. For a single axis microcoil, maximal temperature increases were 0.73-1.91°C in air and 0.45-0.55°C in saline. In vivo, delayed contrast enhanced MRI revealed no evidence of vascular injury and histopathological sections from the common carotid arteries confirmed the lack of vascular damage. CONCLUSIONS Microcatheter tip microcoils for endovascular catheter steering in MRI experience minimal RF heating under the conditions tested. These data provide the basis for further in vivo testing of this promising technology for endovascular interventional MRI. PMID:21075019

  19. Stuck suction catheter in endotracheal tube.

    PubMed

    Raut, Monish S; Joshi, Sandeep; Maheshwari, Arun

    2015-02-01

    Endotracheal tube (ETT) suction is essential to clear secretions so that airway patency can be maintained. Stuck suction catheter in ETT is an uncommon event, and it can be dangerous in patients with difficult airway cases. PMID:25722554

  20. Stuck suction catheter in endotracheal tube

    PubMed Central

    Raut, Monish S.; Joshi, Sandeep; Maheshwari, Arun

    2015-01-01

    Endotracheal tube (ETT) suction is essential to clear secretions so that airway patency can be maintained. Stuck suction catheter in ETT is an uncommon event, and it can be dangerous in patients with difficult airway cases. PMID:25722554

  1. Advanced Imaging Catheter: Final Project Report

    SciTech Connect

    Krulevitch, P; Colston, B; DaSilva, L; Hilken, D; Kluiwstra, J U; Lee, A P; London, R; Miles, R; Schumann, D; Seward, K; Wang, A

    2001-07-20

    Minimally invasive surgery (MIS) is an approach whereby procedures conventionally performed with large and potentially traumatic incisions are replaced by several tiny incisions through which specialized instruments are inserted. Early MIS, often called laparoscopic surgery, used video cameras and laparoscopes to visualize and control the medical devices, which were typically cutting or stapling tools. More recently, catheter-based procedures have become a fast growing sector of all surgeries. In these procedures, small incisions are made into one of the main arteries (e.g. femoral artery in the thigh), and a long thin hollow tube is inserted and positioned near the target area. The key advantage of this technique is that recovery time can be reduced from months to a matter of days. In the United States, over 700,000 catheter procedures are performed annually representing a market of over $350 million. Further growth in this area will require significant improvements in the current catheter technology. In order to effectively navigate a catheter through the tortuous vessels of the body, two capabilities must exist: imaging and positioning. In most cases, catheter procedures rely on radiography for visualization and manual manipulation for positioning of the device. Radiography provides two-dimensional, global images of the vasculature and cannot be used continuously due to radiation exposure to both the patient and physician. Intravascular ultrasound devices are available for continuous local imaging at the catheter tip, but these devices cannot be used simultaneously with therapeutic devices. Catheters are highly compliant devices, and manipulating the catheter is similar to pushing on a string. Often, a guide wire is used to help position the catheter, but this procedure has its own set of problems. Three characteristics are used to describe catheter maneuverability: (1) pushability -- the amount of linear displacement of the distal end (inside body) relative to

  2. Comparative efficacy of stellate ganglion block with bupivacaine vs pulsed radiofrequency in a patient with refractory ventricular arrhythmias.

    PubMed

    Hayase, Justin; Vampola, Stephen; Ahadian, Farshad; Narayan, Sanjiv M; Krummen, David E

    2016-06-01

    There is increasing interest in interventional therapies targeting the cardiac sympathetic nervous system to suppress ventricular arrhythmias. In this case report, we describe an 80-year-old patient with ischemic cardiomyopathy and multiple implantable cardioverter-defibrillator shocks due to refractory ventricular tachycardia and ventricular fibrillation who was unable to continue biweekly stellate ganglion block procedures using bupivacaine 0.25% for suppression of his arrhythmias. He had previously failed antiarrhythmic drug therapy with amiodarone, catheter ablation, and attempted surgical autonomic denervation. He underwent pulsed radiofrequency treatment (3 lesions, 2 minutes each, temperature 42°C, 2-Hz frequency, 20-millisecond pulse width) of the left stellate ganglion resulting in persistent arrhythmia suppression for more than 12 months duration. This represents the first report of a pulsed radiofrequency stellate ganglion lesion providing long-term suppression of ventricular arrhythmias. Further study of this technique in patients with refractory ventricular tachycardia or ventricular fibrillation is warranted. PMID:27185701

  3. Catheter Ablation of Arrhythmia During Pregnancy.

    PubMed

    Driver, Kevin; Chisholm, Christian A; Darby, Andrew E; Malhotra, Rohit; Dimarco, John P; Ferguson, John D

    2015-06-01

    Cardiac arrhythmia as a complication of pregnancy can be problematic to maternal health and fetal life and development. Catheter ablation of tachyarrhythmias during pregnancy has been successfully performed in selected patients with limited experience. Techniques to limit maternal and fetal radiation exposure, including intracardiac echo and electroanatomic mapping systems, are particularly important in this setting. Specific accommodations are necessary in the care of the gravid patient during catheter ablation. PMID:25828853

  4. Mechanical properties and imaging characteristics of remanufactured intravascular ultrasound catheters.

    PubMed

    Hoffmann, R; Haager, P; Mintz, G; Klues, H

    2000-02-01

    Intravascular ultrasound (IVUS) as a routine device in interventional cardiology is handicapped by its high price. 19 factory-made, 'remanufactured' IVUS catheters which consist of sterilized, used phased-array IVUS transducers inserted into a new catheter shaft were compared with 23 new IVUS catheters. 3 mechanical and 4 imaging characteristics were assessed on a 5 point scale (1 = unacceptable, 5 = excellent). Mechanical as well as imaging properties of 'remanufactured' IVUS catheter were comparable to new catheters with excellent ratings for each of the evaluated characteristics in 38 to 94% of 'remanufactured' catheters and 50 to 96% of new catheters. The initial failure rate for 'remanufactured' IVUS catheters was 31.6% vs. 4.3% for new catheters (P < 0.05). Overall failure rate was 47.3% for "remanufactured" catheters vs. 8.7% for new catheters (P < 0.05). The failure was due to an electronic connecting problem occurring during mechanical stress to the IVUS catheter. In conclusion, 'remanufactured' IVUS catheters offer mechanical and imaging characteristics which are comparable to new catheters. Improvements in the 'remanufacturing' process to resolve the high rate of electronic connecting problems may make this a promising approach to substantially lower the price of IVUS catheters. PMID:10832621

  5. Haemolyzed samples: responsibility of short catheters.

    PubMed

    Raisky, F; Gauthier, C; Marchal, A; Blum, D

    1994-01-01

    The haemolysis of blood samples is a source of error in the electrolytic and enzymatic determination in clinical biochemistry. This circumstance seems dependent on the material used for the venepuncture. In this study we compared three kinds of material in 350 patients who were sampled in the emergency department. This randomized study compared the haemolysis of blood samples collected with stainless steel needles and short catheters, either Teflon FEP (Cathlon Critikon) or polyurethane Vialon (Insyte Becton-Dickinson). Quantification of hemolysis was performed by assay of the optical density of plasma haemoglobin. Results were analysed, after verification of the randomization, by one-way analysis of variance by ranks. This study demonstrated a highly significant relation between occurrence of haemolysis and the sampling material, used according to its technical obligations. Haemolysis occurred frequently when short catheters were used in 42% and 55% of cases with the Teflon and Vialon catheters, respectively. Haemolysis was much less frequent with stainless steel needles (12%). This difference was even more marked for haemoglobin levels above 1.5 milligrams of plasma, where the incidence was 4.2%, 9% and 30%, respectively, for the stainless steel needles, the Teflon catheter and the Vialon catheter. This study induced our emergency department to take more blood samples with a needle, even if an infusion was to be given subsequently, or to take them using a Teflon catheter. PMID:7840428

  6. Magnetocardiographically-guided catheter ablation.

    PubMed

    Fenici, R R; Covino, M; Cellerino, C; Di Lillo, M; De Filippo, M C; Melillo, G

    1995-12-01

    After more than 30 years since the first magnetocardiographic (MCG) recording was carried out with induction coils, MCG is now approaching the threshold of clinical use. During the last 5 years, in fact, there has been a growing interest of clinicians in this new method which provides an unrivalled accuracy for noninvasive, three-dimensional localization of intracardiac source. An increasing number of laboratories are reporting data validating the use of MCG as an effective method for preoperative localization of arrhythmogenic substrates and for planning the best catheter ablation approach for different arrhythmogenic substrates. In this article, available data from literature have been reviewed. We consider the clinical use of MCG to localize arrhythmogenic substrates in patients with Wolff-Parkinson-White syndrome and in patients with ventricular tachycardia in order to assess the state-of-the-art of the method on a large number of patients. This article also addresses some suggestions for industrial development of more compact, medically oriented MCG equipments at reasonable cost. PMID:10159774

  7. [Ablation using radiofrequency in the treatment of ventricular tachycardia].

    PubMed

    Cordero Cabra, J A; Iturralde Torres, P; Lara Vaca, S; Colín Lizalde, L; Kershenovich, S; Carvajal, A; González Hermosillo, J A

    1996-01-01

    We performed radiofrequency catheter ablation in 14 consecutive patients with Ventricular Tachycardia (VT) 10 of which had healthy hearts, one patient with ischemic heart disease, one with arrhythmogenic dysplasia, one with dilated cardiomyopathy, and one with congenital heart disease. The localization of the VT was: 10 in the left posterior fascicular region, 3 in the right ventricular outflow tract (RVOT), and one patient with ischemic heart disease with the substrate in the left ventricular apex. All of them with VT refractory to pharmacological management, using an average of 2.7 drugs per patient. After all patients underwent Electrophysiological Study (EPS), an intracavitary mapping was performed, in order to locate the arrhythmogenic substrate. Later on, the RF ablation was performed, delivering an average of 15 pulses, using 40 Watts, and an average time of 25 sec. per pulse. The procedure was successful in 60% of the fascicular VT, with a 16% of recurrence; 100% of success with those originated in the RVOT with no recurrence; in the ischemic patient we achieved primary success, but with recurrence, a second session was successful with no recurrence up to date. No major complications occurred in this group. Those patients which showed no success required the use of antiarrhythmic drugs. The total success of the series is 71.4% with 10% recurrence, and no mortality. PMID:8967816

  8. Radiofrequency Ablation of Metastatic Pheochromocytoma

    PubMed Central

    Venkatesan, Aradhana M.; Locklin, Julia; Lai, Edwin W.; Adams, Karen T.; Fojo, Antonio Tito; Pacak, Karel; Wood, Bradford J.

    2013-01-01

    In the present report on the preliminary safety and effectiveness of radiofrequency (RF) ablation for pheochromocytoma metastases, seven metastases were treated in six patients (mean size, 3.4 cm; range, 2.2–6 cm). α- and β-adrenergic and catecholamine synthesis inhibition and intraprocedural anesthesia monitoring were used. Safety was assessed by recording ablation-related complications. Complete ablation was defined as a lack of enhancement within the ablation zone on follow-up computed tomography. No serious adverse sequelae were observed. Complete ablation was achieved in six of seven metastases (mean follow-up, 12.3 months; range, 2.5–28 months). In conclusion, RF ablation may be safely performed for metastatic pheochromocytoma given careful attention to peri-procedural management. PMID:19875067

  9. Trigeminal Neuralgia and Radiofrequency Lesioning

    PubMed Central

    Eugene, Andy R.

    2016-01-01

    Trigeminal Neuralgia is a disorder that is characterized with electrical-type shocking pain in the face and jaw. This pain may either present as sharp unbearable pain unilateral or bilaterally. There is no definite etiology for this condition. There are various treatment methods that are currently being used to relieve the pain. One of the pharmacological treatments is Carbamazepine and the most prevalent surgical treatments include Gamma Knife Surgery (GKS), Microvascular Decompression (MVD) and Radiofrequency Lesioning (RFL). Although, MVD is the most used surgical method it is not an option for all the patients due to the intensity of the procedure. RFL is used when MVD is not suitable. In this paper we present the various options in the treatment of Trigeminal Neuralgia. PMID:26770820

  10. Reducing inappropriate urinary catheter use: quality care initiatives.

    PubMed

    Buckley, Catherine; Clements, Charlotte; Hopper, Adrian

    Healthcare-acquired urinary infection presents a substantial burden for patients and the healthcare system. Urinary tract infections have not gained the same level of media attention as other healthcare-associated infections, yet interventions to reduce urinary catheter use are one of the top ten recommended patient safety strategies. To improve practice around urinary catheter placement and removal requires interventions to change the expectations and habits of nurses, medical teams and patients regarding the need for a urinary catheter. In the authors' trust, a redesign of the existing urinary catheter device record was undertaken to help avoid unnecessary placement of catheters, and resulted in a reduction of urinary catheters in situ longer than 48 hours. Other strategies included implementation of catheter rounds in a high-usage area, and credit-card-sized education cards. A catheter 'passport' was introduced for patients discharged with a catheter to ensure information for insertion and ongoing use were effectively communicated. PMID:25978469

  11. Strategies for the control of catheter encrustation.

    PubMed

    Stickler, D J; Evans, A; Morris, N; Hughes, G

    2002-06-01

    Two general strategies have been adopted to develop catheter materials that resist encrustaion by bacterial biofilms: (a) the incorporation of antimicrobial agents into the polymers and (b) the production of materials with surface properties which prevent the adherence of bacterial cells. Our experience to develop non-adherent surfaces which abstracts design from nature is reported. Compounds based on 2-methacryloloxyethylphosphorylcholine co-polymerised with long-chain alkyl methacrylates have been produced which have structural and surface properties similar to those of the outer membranes of erythrocytes. These PC-coatings have been applied onto catheter base materials where they produce polar surfaces that are extremely hydrophilic. In experiments using a laboratory model of the catheterised bladder we found that the PC-coatings did not reduce colonisation of latex or silicone catheters by crystalline Proteus mirabilis biofilm. There were no significant difference between the amounts of calcium and magnesium salts deposited on coated and non-coated catheters. In a further set of experiments the PC-coatings did not significantly increase the mean times for which catheters drained freely. In a parallel clinical study, the performance of PC-coated ureteral stents was investigated. Scanning electron microscopy and bacteriological analysis on 44 PC-coated stents that had been implanted in patients for 12-week periods and 28 control stents suggested that the PC-coated devices were less vulnerable to encrustation and colonisation by bacterial biofilm than normal stents. It was of interest that in contrast to encrusted catheters, urease producing species such as P. mirabilis were rarely isolated from the stents. The main organisms colonising the stents were enterococci and coagulase-negative staphylococci. These results suggest that the mechanisms of catheter and stent encrustation may be different and require different strategies for control. PMID:12135840

  12. Radiofrequency quadrupole accelerators and their applications

    SciTech Connect

    Stokes, R.H.; Wangler, T.P.

    1988-01-01

    This review of Radiofrequency Quadrupole (RFQ) Acelerators contains a short history of Soviet and Los Alamos RFQ developments, RFQ beam dynamics, resonator structures, and the characteristics and performance of RFQ accelerators. (AIP)

  13. Conversion of Non-Tunneled to Tunneled Hemodialysis Catheters

    SciTech Connect

    Ha, Thuong G. Van Fimmen, Derek; Han, Laura; Funaki, Brian S.; Santeler, Scott; Lorenz, Jonathan

    2007-04-15

    Purpose. To determine the safety and efficacy of conversion of non-tunneled (temporary) catheters to tunneled catheters in hemodialysis patients. Methods. A retrospective review of 112 consecutive conversions in 111 patients was performed over a period of 4 years. Fourteen patients were lost to follow-up. The remaining 97 patients had clinical follow-up. Temporary catheters were converted to tunneled catheters utilizing the same internal jugular venotomy sites and a modified over-the-wire technique with use of a peel-away sheath . Follow-up clinical data were reviewed. Results. Technical success was achieved in all 112 procedures. None of the 97 patients with follow-up suffered early infection within 30 days. The total number of follow-up catheter days was 13,659 (range 2-790). Cases of confirmed and suspected bacteremia requiring catheter removal occurred at a frequency of 0.10 per 100 catheter days. Suspected catheter infection treated with antibiotics but not requiring catheter intervention occurred at a frequency of 0.04 per 100 catheter days. Frequency of all suspected or confirmed infections was 0.14 per 100 catheter days. Catheter interventions as a result of poor blood flow, inadvertent removal, catheter fracture, or kinking occurred at a rate of 0.18 per 100 catheter days. Life table analysis revealed primary patency rates of 86%, 64%, and 39% at 30 days, 90 days, and 180 days, respectively. Conclusion. Conversion of temporary catheters to tunneled catheters using the pre-existing venotomy sites is safe and has low rates of infection and malfunction. These rates are comparable to previously published rates for tunneled catheters placed de novo and tunneled catheter exchanges.

  14. [Swan Ganz catheter. Experts opinion].

    PubMed

    Cohen Arazi, Hernán; Nani, Sebastián; Giorgi, Mariano; Guardiani, Fernando; Caturla, Nicolás; Benzadón, Mariano

    2014-01-01

    Investigators have raised doubts as to the safety of the Swan Ganz catheter (SGC). In order to define the point of view of cardiologists in our country, the Argentine Society of Cardiology's Emergency Council organized a meeting to analyze their views in different settings (non-cardiac surgery, cardiac surgery, acute coronary syndromes and heart failure) using the RAND-UCLA appropriateness method. A detailed review with the scientific evidence was sent to the experts in cardiology prior to the meeting in the SAC auditorium where the panellists selected the clinical variables create the specific situations. These hypothetic situations were resent to the panellists at a second stage for their individual evaluation, rating the benefit-to-harm ratio of the procedure on a scale of 1 to 9 (1 meant that the expected harms greatly outweighed the expected benefits, and 9 that the expected benefits greatly outweighed the expected harms, 5 could mean either that the harms and benefits were roughly equal). Two experts analyzed the results, describing the agreement/disagreement ratio. Finally, each indication was classified as "appropriate" "uncertain" or "inappropriate" ,for the procedure in accordance with the panelists' median score: median scores in the 1-3 range were classified as inappropriate, those in the 4-6 range as uncertain, and those in the 7-9 range as appropriate. We observed high disagreement rates in SGC indications between cardiologists. However, the panelists were in favor of SGC use when situations included shock and myocardial dysfunction, especially in the presence of organic dysfunction. There were some situations when panelists considered SGC not useful, in patients without organ failure. PMID:25188663

  15. How to manage an arterial catheter.

    PubMed

    Parry, Andrew; Higginson, Ray

    2016-03-16

    Rationale and key points This article provides nurses with information on the safe and effective use and management of arterial catheters, the gold standard for accurate blood pressure measurement and routine serial blood gas sampling in critical care. Arterial catheters are used when real-time blood pressure monitoring is required, such as when there is a risk of significant blood loss. ▶ Arterial catheters provide real-time blood pressure monitoring, enabling rapid identification of changes in blood pressure and guiding fluid resuscitation. ▶ Arterial catheters can be used to take blood samples without having to perform multiple arterial or venous punctures. Reflective activity Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. How this article will change your practice when managing a patient with an arterial catheter. 2. Any further learning needs you have identified. Subscribers can upload their reflective accounts at: rcni.com/portfolio . PMID:26982866

  16. Nonholonomic catheter path reconstruction using electromagnetic tracking

    NASA Astrophysics Data System (ADS)

    Lugez, Elodie; Sadjadi, Hossein; Akl, Selim G.; Fichtinger, Gabor

    2015-03-01

    Catheter path reconstruction is a necessary step in many clinical procedures, such as cardiovascular interventions and high-dose-rate brachytherapy. To overcome limitations of standard imaging modalities, electromagnetic tracking has been employed to reconstruct catheter paths. However, tracking errors pose a challenge in accurate path reconstructions. We address this challenge by means of a filtering technique incorporating the electromagnetic measurements with the nonholonomic motion constraints of the sensor inside a catheter. The nonholonomic motion model of the sensor within the catheter and the electromagnetic measurement data were integrated using an extended Kalman filter. The performance of our proposed approach was experimentally evaluated using the Ascension's 3D Guidance trakStar electromagnetic tracker. Sensor measurements were recorded during insertions of an electromagnetic sensor (model 55) along ten predefined ground truth paths. Our method was implemented in MATLAB and applied to the measurement data. Our reconstruction results were compared to raw measurements as well as filtered measurements provided by the manufacturer. The mean of the root-mean-square (RMS) errors along the ten paths was 3.7 mm for the raw measurements, and 3.3 mm with manufacturer's filters. Our approach effectively reduced the mean RMS error to 2.7 mm. Compared to other filtering methods, our approach successfully improved the path reconstruction accuracy by exploiting the sensor's nonholonomic motion constraints in its formulation. Our approach seems promising for a variety of clinical procedures involving reconstruction of a catheter path.

  17. Catheter-associated urinary tract infections.

    PubMed

    Liedl, B

    2001-01-01

    In the past few years it has been clearly demonstrated that the concept of bacterial biofilm production permits an understanding and provides some explanation of the pathogenesis, diagnosis and treatment of catheter-associated urinary tract infections. This concept describes the colonization of catheter surfaces and the movement of bacteria against the urinary flow. It explains the antibacterial resistance of these matrix-enclosed sessile populations of bacteria. The catheter encrustation can be observed as mineralizing bacterial biofilm. The differentiation in swarming cells exposing a much higher activity of the enzyme urease is responsible for the predominant role of Proteus mirabilis in obstructing encrustations. The guidelines for the prevention of catheter-associated urinary tract infections were developed over the past decades by clinicians and are still valid. They can now be better understood taking into consideration these new theories. As overuse of urethral catheters and non-compliance of their recommended use are still apparent, educational and surveillance programmes are needed to help maintain good standards of care. PMID:11148750

  18. Stereotactic catheter placement for Ommaya reservoirs.

    PubMed

    Kennedy, Benjamin C; Brown, Lauren T; Komotar, Ricardo J; McKhann, Guy M

    2016-05-01

    Ommaya reservoirs are an important surgical therapy for the chronic intrathecal administration of chemotherapy for patients with leptomeningeal carcinomatosis. Surgical accuracy is paramount in these patients with typically normal sized ventricles, and may be improved with stereotactic guidance. This paper aimed to review a large series of stereotactic Ommaya catheter placements, examining accuracy and complications. We conducted a retrospective review of 109 consecutive adult patients who underwent stereotactic Ommaya catheter placement for leptomeningeal carcinomatosis or central nervous system lymphoma at Columbia University Medical Center, USA, from 1998-2013. The rate of accurate placement in the ventricular system was 99%, with the only poor catheter position due to post-placement migration. The rate of peri-operative complications was 6.4%. Hemorrhagic complications occurred in patients with thrombocytopenia or therapeutic anti-coagulation pre-operatively or during the post-operative period. Use of stereotaxy for catheter placement of Ommaya reservoirs is safe and effective, and should be considered when placing a catheter into non-hydrocephalic ventricles. PMID:26778516

  19. Catheter Ablation for Long-Standing Persistent Atrial Fibrillation

    PubMed Central

    Romero, Jorge; Gianni, Carola; Di Biase, Luigi; Natale, Andrea

    2015-01-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and represents a major burden to health care systems. Atrial fibrillation is associated with a 4- to 5-fold increased risk of thromboembolic stroke. The pulmonary veins have been identified as major sources of atrial triggers for AF. This is particularly true in patients with paroxysmal AF but not always the case for those with long-standing persistent AF (LSPAF), in which other locations for ectopic beats have been well recognized. Structures with foci triggering AF include the coronary sinus, the left atrial appendage (LAA), the superior vena cava, the crista terminalis, and the ligament of Marshall. More than 30 studies reporting results on radiofrequency ablation of LSPAF have been published to date. Most of these are observational studies with very different methodologies using different strategies. As a result, there has been remarkable variation in short- and long-term success, which suggests that the optimal ablation technique for LSPAF is still to be elucidated. In this review we discuss the different approaches to LSPAF catheter ablation, starting with pulmonary vein isolation (PVI) through ablation lines in different left atrial locations, the role of complex fractionated atrial electrograms, focal impulses and rotor modulation, autonomic modulation (ganglionated plexi), alcohol ablation, and the future of epicardial mapping and ablation for this arrhythmia. A stepwise ablation approach requires several key ablation techniques, such as meticulous PVI, linear ablation at the roof and mitral isthmus, electrogram-targeted ablation with particular attention to triggers in the coronary sinus and LAA, and discretionary right atrial ablation (superior vena cava, intercaval, or cavotricuspid isthmus lines). PMID:26306125

  20. Left Atrial Anatomy Relevant to Catheter Ablation

    PubMed Central

    Sánchez-Quintana, Damián; Cabrera, José Angel; Saremi, Farhood

    2014-01-01

    The rapid development of interventional procedures for the treatment of arrhythmias in humans, especially the use of catheter ablation techniques, has renewed interest in cardiac anatomy. Although the substrates of atrial fibrillation (AF), its initiation and maintenance, remain to be fully elucidated, catheter ablation in the left atrium (LA) has become a common therapeutic option for patients with this arrhythmia. Using ablation catheters, various isolation lines and focal targets are created, the majority of which are based on gross anatomical, electroanatomical, and myoarchitectual patterns of the left atrial wall. Our aim was therefore to review the gross morphological and architectural features of the LA and their relations to extracardiac structures. The latter have also become relevant because extracardiac complications of AF ablation can occur, due to injuries to the phrenic and vagal plexus nerves, adjacent coronary arteries, or the esophageal wall causing devastating consequences. PMID:25057427

  1. The importance of effective catheter securement.

    PubMed

    Fisher, Jayne

    This article examines the importance of securing/fixing indwelling urinary catheters. The Oxford English dictionary interlinks the two words-'secure' and 'fix'-as having the same meaning. To secure the catheter should not be confused with 'support', whereby the weight of the urine drainage bag is supported with the use of velcro straps or a sleeve. The author introduces the need for the concept of this practice to be at the forefront of nurses' minds in all settings, and this is demonstrated through the use of case studies. Current guidance in this area is reviewed, as well as the problems that can arise when catheters are not secured properly and the available products for health professionals to use. PMID:20948482

  2. Catheter tip force transducer for cardiovascular research

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Lewis, G. W.; Silver, R. H.; Culler, V. H. (Inventor)

    1976-01-01

    A force transducer for measuring dynamic force activity within the heart of a subject essentially consists of a U-shaped beam of low elastic compliance material. Two lines extend from the beams's legs and a long coil spring is attached to the beam. A strain gauge is coupled to one of the beam's legs to sense deflections thereof. The beam with the tines and most of the spring are surrounded by a flexible tube, defining a catheter, which is insertable into a subject's heart through an appropriate artery. The tines are extractable from the catheter for implantation into the myocardium by pushing on the end of the spring which extends beyond the external end of the catheter.

  3. Everting (toposcopic) catheter for broad clinical application.

    PubMed

    Shook, D R; Doppman, J L; Cattau, E L; Goldstein, S R

    1986-05-01

    The advanced development of the clinical everting (toposcopic) catheter is described. A detailed discussion of the design and outline of the fabrication techniques are followed by a thorough performance evaluation and summary of the first two clinical applications. The everting element is a low-durometer thermoplastic polyurethane elastomer. Surface treatments include the bonding of a hydrophilic polymeric coating, optimized for lubricity, to the sliding internal surfaces of the catheter. Eversion pressures and infusion/aspiration flow rates have been measured under various conditions and the infusate-in-blood mixing potential investigated. A preliminary assessment is given of the clinical performance of the catheter in the vascular delivery of chemotherapy and standard endoscopic retrograde cholangiopancreatography. PMID:3724105

  4. Ventriculoperitoneal Shunt Peritoneal Catheter Knot Formation

    PubMed Central

    Ul-Haq, Anwar; Al-Otaibi, Faisal; Alshanafey, Saud; Sabbagh, Mohamed Diya; Al Shail, Essam

    2013-01-01

    The ventriculoperitoneal (VP) shunt is a common procedure in pediatric neurosurgery that carries a risk of complications at cranial and abdominal sites. We report on the case of a child with shunt infection and malfunction. The peritoneal catheter was tethered within the abdominal cavity, precluding its removal. Subsequently, laparoscopic exploration identified a knot at the distal end of the peritoneal catheter around the omentum. A new VP shunt was inserted after the infection was healed. This type of complication occurs rarely, so there are a limited number of case reports in the literature. This report is complemented by a literature review. PMID:24109528

  5. Catheter-related bacteremia by Cupriavidus metallidurans.

    PubMed

    D'Inzeo, Tiziana; Santangelo, Rosaria; Fiori, Barbara; De Angelis, Giulia; Conte, Viola; Giaquinto, Alessia; Palucci, Ivana; Scoppettuolo, Giancarlo; Di Florio, Viviana; Giani, Tommaso; Sanguinetti, Maurizio; Rossolini, Gian Maria; Spanu, Teresa

    2015-01-01

    Cupriavidus bacteremia is a rare infection and identification of the pathogen is difficult. We present four cases of bacteremia by Cupriavidus metallidurans that were initially identified to the genus level by both Bruker and Vitek matrix-assisted laser desorption ionization-time of flight mass spectrometry and later identified to the species level by 16S rRNA gene sequencing. To our knowledge, these are the first cases of C. metallidurans catheter-related infections. Patients were successfully treated with antibiotic therapy and catheter removal. PMID:25446890

  6. Catheter ablation of inappropriate sinus tachycardia.

    PubMed

    Gianni, Carola; Di Biase, Luigi; Mohanty, Sanghamitra; Gökoğlan, Yalçın; Güneş, Mahmut F; Horton, Rodney; Hranitzky, Patrick M; Burkhardt, J David; Natale, Andrea

    2016-06-01

    Catheter ablation for inappropriate sinus tachycardia (IST) is recommended for patients symptomatic for palpitations and refractory to other treatments. The current approach consists in sinus node modification (SNM), achieved by ablation of the cranial part of the sinus node to eliminate faster sinus rates while trying to preserve chronotropic competence. This approach has a limited efficacy, with a very modest long-term clinical success. To overcome this, proper patient selection is crucial and an epicardial approach should always be considered. This brief review will discuss the current role and limitations of catheter ablation in the management of patients with IST. PMID:26310299

  7. [Phlebitogenicity of venous catheters of Vialon].

    PubMed

    Fassolt, A

    1985-12-01

    During three days 132 surgical patients with postoperative infusion treatment were checked on the frequency of venous reactions in the arms when catheters/cannulas of 4 different materials were used and the outcome compared. A significant result was obtained in connection with the I-cath catheter made of vialon (a polyurethanelike resin polymer) and the L-cath of polyurethane. Phlebitis was decreased to 27.3% resp. 24.2% - approximately half of its usual frequency - when I-cath of polyvinyl-chloride and FEP-teflon vasofix cannulas were applied (both 51.5%). The different predisposing factors of infusion phlebitis are under discussion. PMID:4093198

  8. Central Venous Access Catheters (CVAC) and Gastrostomy (Feeding) Tubes

    MedlinePlus

    ... Membership Directory (SIR login) Interventional Radiology Central Venous Access Catheters (CVAC) and Gastrostomy (Feeding) Tubes People with ... without surgery by an interventional radiologist. Central Venous Access Catheters (CVAC) A CVAC is a tube that ...

  9. Proteus mirabilis biofilms and the encrustation of urethral catheters.

    PubMed

    Stickler, D; Ganderton, L; King, J; Nettleton, J; Winters, C

    1993-01-01

    Bacterial biofilms were observed on 69 of 75 catheters taken from patients undergoing long-term bladder management. Ten catheters were colonized by pure cultures of Proteus mirabilis. In each of these cases the bacteria formed layers on the catheter surface, underlying encrustations of struvite and hydroxyapatite which partially or completely occluded the catheter lumen. Encrustation was also apparent on catheters colonized by P. mirabilis plus other species, but was rarely seen on catheters colonized by non-urease-producing species. These observations support the hypothesis that catheter encrustation is brought about by the activity of urease-producing biofilms and confirms that the main target in the control of catheter encrustation should be P. mirabilis. PMID:8171763

  10. Reduced intravascular catheter-related infection by routine use of antibiotic-bonded catheters in a surgical intensive care unit.

    PubMed

    Kamal, G D; Divishek, D; Kumar, G C; Porter, B R; Tatman, D J; Adams, J R

    1998-03-01

    We report a comparative analysis of intravascular catheter-related infection before and after routine use of antibiotic-bonded catheters in an intensive care unit. Cefazolin-bonded catheters were placed in patients requiring catheterization for at least 3 days, or with remote infection, standard catheters at other times. One thousand forty-five catheters (259 patients) over 6 months were compared with 801 (236 antibiotic-bonded, 565 standard) catheters (239 patients) the next 6 months. After use of antibiotic-bonded catheters, we found: 1.7% catheters infected versus 3.7% (p = 0.01); catheter-associated bacteremia 0.1% versus 1.3% (p < 0.005); catheter-related infection rate 4.39 versus 10.73 per 1000 patient days (p < 0.005), and 5.06 versus 11.47 per 1000 catheter days (p < 0.01); and cumulative risk of infection decreased (p < 0.005). Antibiotic-bonded catheters were used with more remote infections (52% versus 27%, p < 0.001), had longer indwelling time (4.4 versus 3.1 days, p = 0.0001), and more were inserted over a guide wire (66% vs. 28%, p < 0.001). In conclusion routine use of antibiotic-bonded catheters was associated with a significant reduction in infectious complications. PMID:9572020