Reduction In Fluoroscopy Time Research Articles

An anatomical study comparing standard fluoroscopy and virtual fluoroscopy for the placement of C1–2 transarticular screws

The authors sought to compare radiation exposure, surgical time, and accuracy of screw placement when using either standard fluoroscopy or virtual fluoroscopy for the placement of C1-2 transarticular screws. Twenty-two C1-2 transarticular screws were placed in 11 cadavers in a randomized and alternating order by using either standard fluoroscopy or virtual fluoroscopy (fluoronavigation). The radiation time, procedure time, and accuracy of screw placement were recorded and statistically compared. A small but statistically significant reduction in fluoroscopy time was noted with the virtual fluoroscopy technique but the surgical times were similar between the two techniques. The incidence of noncritical and critical breaches (those at risk of causing a neurovascular injury) was not significantly different between the two groups. Careful analysis of the C1-2 anatomy in these specimens underscored the importance of placing the screw path in a maximally dorsal and medial portion of the C-2 isthmus to avoid injury to the vertebral artery and to maximize the bone purchase of the C-1 lateral mass. Although virtual fluoroscopy may represent a useful tool for transarticular screw placement, it does not supplant traditional surgical techniques and does not appear to lower the incidence of bone breaches that can occur when performing this demanding procedure.

Differences in success of repeat ablation procedure for recurrent atrial fibrillation after two different ablation strategies: Results from a prospective randomized study comparing pulmonary vein isolation versus circumferential pulmonary vein ablation

Minnesota.) non-fluoroscopic mapping system has the potential to reduce X-ray exposure during electrophysiological procedures. This is the first prospective randomised controlled study to compare radiation exposure, safety and cost between conventional, electroanatomical (Carto) and high frequency electrical field (NavX) mapping techniques. Methods: All patients undergoing catheter ablation (except AV node and AF ablation) were randomised to a Carto, NavX or conventional mapping procedures. Immediate procedural success was defined using standard criteria (eg bi-directional block for typical atrial flutter, non inducibilty of AVNRT/AVRT etc). All patients were seen 6 weeks following the procedure and success defined as both freedom from symptoms and no documented recurrence of any arrhythmia other than ectopy. Procedure costs included diagnostic and ablation catheters, Carto reference patch and the complete NavX kit. All costs are the published UK list prices. Statistical comparison was made against conventional procedures. Results: Eighty-nine patients (54% men) aged 48 17 (mean SD) were randomised. 5 patients were withdrawn as no arrhythmia could be induced. There were no significant differences between Carto and NavX in any variable. Conclusion: For all catheter ablation procedures, procedure duration and outcome are similar for Carto, Navx and conventional procedures. Both Carto and NavX are associated with reduced fluoroscopy time and radiation dose compared to conventional x-rays but at an increased cost. The costs of NavX are likely to reduce as we become more comfortable using fewer catheters for EP procedures.

Ablation of atrial fibrillation: Energy sources and navigation tools: A review

a d c U t w t p i t s l c a t p t t t e r l t a e ( c s t f a t a t r u m a v Inspired by the pioneering work of Michel Haisaguerre (1), transvenous ablation of atrial fibrillaion (AF) has become the most exciting and innoative field in interventional electrophysiology. ven though radiofrequency current remains to be ost widely used, alternative energy sources such s cryoand ultrasound energy have gained inreasing attention in an attempt to overcome cerain limitations associated with this technology. urthermore, various navigation tools have been ntroduced aiming to reduce fluoroscopy time and mprove catheter steering. This review provides a escription and critical comparison of energy ources and navigation tools currently available for ransvenous AF ablation in humans.

Computer aided long bone fracture treatment

Intraoperative fluoroscopy is the tool for intraoperative control of long bone fracture reduction and osteosynthesis. Limitations of this technology include: High radiation exposure to the patient and the surgical team, limited field of view, image distortion, limitation to 2-D representations, and cumbersome updating of verification images. Fluoroscopy based navigation systems partially address these limitations by allowing fluoroscopic images to be used for real-time surgical localization and instrument tracking. In a clinical study on computer guidance by virtual fluoroscopy for distal locking, the capability to provide online guidance with significantly reduced fluoroscopy times is demonstrated. Virtual fluoroscopy applied for guidewire placement in a laboratory setup demonstrated the potential of the method to reduce procedure times, and the potential to increase precision of implant placement with decreased fluoroscopy times. By using virtual reality enhancement, starting from multiple registered fluoroscopy images, a virtual 3-D cylinder model for each principal bone fragment is reconstructed. This spatial cylinder model is not only used to supply a 3-D image of the fracture, but also allows effective fragment projection extraction from the fluoroscopic images and further achieves radiation-free updates of in-situ surgical fluoroscopic images through a non-linear interpolation and warping algorithm. After primary image acquisition, the image intensifier was replaced by the virtual reality system. It was shown that all the steps of the procedure, including fracture reduction and LISS osteosynthesis can be performed completely in virtual reality.

Technical Results and Effects of Operator Experience on Uterine Artery Embolization for Fibroids: The Ontario Uterine Fibroid Embolization Trial

To document the technical results and spectrum of practice of uterine artery embolization (UAE) for fibroids in the health care setting in Canada. The effects of interventional radiologist's (IR's) experience with UAE on procedure and fluoroscopy time were also investigated. The study involved a multicenter prospective single-arm clinical treatment trial and included the practices of 11 IRs at eight university-affiliated teaching and community hospitals. Vascular access with percutaneous femoral artery approach was followed by transcatheter delivery of polyvinyl alcohol (PVA) particles into uterine arteries with fluoroscopic guidance. Technical success, complications, procedural time, fluoroscopy time, and effects of operator experience were outcomes analyzed. Between November 1998 and November 2000, 570 embolization procedures were performed in 555 patients. UAE was bilaterally successful in 97% (95% CI: 95%-98%). Variant anatomy was the most common reason for failure to embolize bilaterally. The procedural complication rate was 5.3% (95% CI: 3.6%-7.4%). Of the 30 events, three involved major complications (one seizure and two allergic reactions) that resulted in additional care or extended hospital stay. Procedure time and fluoroscopy time averaged 61 minutes (95% CI; 58-63 minutes) and 18.9 minutes (95% CI; 18-19.8) and varied significantly among IRs (P <.001; P <.001). The average 27% reduction in procedure time (20 minutes; P <.001) and 24% reduction in fluoroscopy time (5.1 minutes; P <.001) with increasing UAE experience were significant. A high level of technical success with few complications was obtained with a variety of operators in diverse practice settings. Increased experience in UAE significantly reduced procedure and fluoroscopy time.

Intracardiac and intraluminal echocardiography: indications and standard approaches

In particular clinical scenarios, transthoracic and transoesophageal echocardiography (TEE) have limitations. This study sought to test if intracardiac and intraluminal echocardiography (ICLE), including 2-D, M-mode and Doppler analysis with a miniaturised, multiple-frequency transducer-tipped catheter, is suitable for assessing distinct cardiac and vascular disorders. ICLE was employed in 10 animals using 6 standard approaches. In 12 patients undergoing device closure of patent foramina ovalia (PFO) ( n = 6) or atrial septal defects (ASD) ( n = 3), or aortic stent implantation ( n = 3), interventional procedures were guided by ICLE and, for comparison, also by TEE. ICLE provided enhanced diagnostic information on the aorta, cardiac valves, main pulmonary vessels and both atria and, therefore, added to the diagnostic spectrum of TEE. Especially for guiding interventional procedures ( e.g., device closure of atrial septal defects and patent foramina ovalia), ICLE was shown to be helpful. Compared with the conventional approach, the technique reduced fluoroscopy time for device closure procedures: 6.5 min vs. 8.9 min, p < 0.0011. With the patient in a supine position, ICLE was better tolerated than TEE. Complications did not occur, either with ICLE or with TEE. In conclusion, ICLE adds to conventional echocardiography and promises to become a clinical alternative for guiding interventional procedures. (E-mail: thomas.bartel@uni-essen.de)

Echocardiography before, during, and after interventions.

Before intervention, a detailed echocardiographic examination is mandatory for the decision whether this procedure will be necessary, possible, and safe. During intervention, transesophageal echocardiography (TEE) is needed for the continuous monitoring of the procedure, immediate assessment of results, and complications. TEE results in a significant reduction of fluoroscopy time. After intervention, echocardiography provides information on long-term results and newly developed complications.

Use of Intracardiac Echocardiography in Interventional Electrophysiology

Intracardiac echocardiography is emerging as a potentially useful tool during RF ablation procedures. There are a number of potential benefits of direct endocardial visualization during RF ablation including: (1) precise anatomical localization of the ablation catheter tip in relation to important endocardial structures, which cannot be visualized with fluoroscopy; (2) reduction in fluoroscopy time; (3) evaluation of catheter tip tissue contact; (4) confirmation of lesion formation and identification of lesion size and continuity; (5) immediate identification of complications; and (6) as a research tool to help in understanding the critical role played by specific endocardial structures in arrhythmogenesis. This article will review existing data and speculate as to possible future roles for intracardiac echocardiography in interventional electrophysiology.

Frameless stereotactic guidance for surgery of the upper cervical spine.

The goal was to evaluate and describe the use of a frameless, computed tomography-guided, stereotactic technique in complex procedures involving the craniocervical junction. Eleven procedures, including transoral odontoid resection, posterior atlantoaxial fusion with transarticular C1-C2 screw fixation, and spinal tumor resection, were performed in the preceding 26 months. In each case, frameless stereotaxy was used to plan the incision, to define resection margins, and to determine the appropriate orientation of instrumentation. There were no intraoperative complications noted. Each patient underwent adequate resection of the pathological lesion and satisfactory placement of instrumentation. The stereotactic system provided detailed anatomic visualization, which increased the confidence of the surgeon during the procedure. The system limited the need for extensive surgical exposure, reduced fluoroscopy time, and decreased the risk of neurovascular injury. Frameless stereotaxy provided the surgeon with intraoperative information regarding the extent of bone and soft tissue resection. It provided a multidimensional view of anatomic relationships in the operative field, which significantly increased surgical accuracy and safety.

Beneficial impact of aorto-coronary graft markers on post-operative angiography

When coronary and graft angiography is required for patients with prior coronary artery bypass (CAB) graft surgery, it is often difficult to localize the proximal aorto-coronary graft anastamosis. Our goal was to quantify the potential benefit during subsequent angiography if the proximal anastamosis is marked by an aorto-coronary graft marker at the time of CAB. Retrospective review of 414 angiograms that were performed for patients with prior CAB. Cohorts with an without graft markers were compared. In the group with aorto-coronary graft markers and > or = 2 aorto-coronary grafts, there were significant reductions in fluoroscopy time (30.5%, p < 0.0001), contrast volume (21.7%, p < 0.0001), and numbers of angiographic catheters used (17.0%, p = 0.0001). If only one aorto-coronary graft was placed and marked, a trend toward reduced fluoroscopy time was observed (23.8%, p = 0.07). This study demonstrates the objective benefit supporting routine placement of circumferential aorto-coronary graft markers during CAB, particularly if > 1 graft is required.

Computer assisted determination of the dose-area product in retrograde urethrography.

Retrograde urethrography (RUG) is a dynamic radiological procedure in which the cumulative dose-area product (DAP) comprises radiation doses derived from both fluoroscopy and radiography. In the present prospective study, digital retrograde urethrographs (Prestilix 1600X/DRS, General Electric) were obtained in 40 consecutive male patients (mean age 60.6 years; range 23-88 years) presenting for evaluation of urinary pathology. The radiation dose was recorded as the dose-area product. From these data, a computer program (Diasoft 2.0, PTW, Freiburg, Germany) then determined the respective proportions of the total radiation dose deriving from fluoroscopy and radiography, as well as the number of radiographic exposures. The average total radiation dose was 316 cGy cm2. In five of the 40 patients examined (12.5%), the number of radiographic exposures registered by the program and, hence, the calculated DAPs were erroneous. In the remaining 35 patients, the average proportion of the cumulative DAP resulting from fluoroscopy was 81%, while that deriving from radiography was 19%. The computer program utilized in this study makes possible an intelligent evaluation of the DAP in dynamic procedures such as RUG. Since fluoroscopy is responsible for 81% of the cumulative DAP at RUG, a significant decrease in applied radiation dose may be achieved by reducing fluoroscopy time or by using pulsed fluoroscopy.

Modified multipurpose catheter enhances clinical utility for cardiac catheterizations

The Multipurpose technique for coronary arteriography employs a single catheter. The benefits are a reduction in the cost of the procedure and a shorter procedural time by experienced operators. To enhance the performance of these catheters, a modification was made in the materials and tip design, and these modifications were clinically evaluated in a small study. Compared to the control group of patients (n = 41), patients catheterized with the Multipurpose-SM (n = 43) were shown to have a shorter procedural time as measured by a reduced fluoroscopy time (7.08 min vs. 9.52 min, P = .007). This difference is statistically significant at a 95% confidence level and resulted in less radiation exposure to the operator and cath lab staff. The procedural time was significantly reduced by fewer catheter exchanges (19% study vs. 46% control; P = .006), which were needed to successfully complete the procedure. The new Multipurpose-SM catheter also demonstrated enhanced flexibility for cannulating coronary arteries with superior or anterior takeoffs. This study concludes that the utilization of a modified Multipurpose-SM catheter is safe and effective in cannulating both the left and right coronary arteries, bypass grafts, and performing left ventriculography. The primary benefits of using this modified catheter are reduced fluoroscopy time and the need for fewer catheter exchanges.

Radiofrequency ablation of accessory pathways: implications of accumulated experience and time dedicated to procedures.

Previous reports on radiofrequency ablation of accessory pathways have shown that the experience of the operator is of crucial importance in reducing fluoroscopy time and achieving higher success rates. However, a detailed analysis of this important issue has not been previously attempted. We analysed 71 consecutive ablation procedures undertaken at St George's Hospital by the same electrophysiology group and always with the same first operator. Of all procedures, 66 (91.6%) were successful, as judged by abolition of accessory pathway conduction without recurrence within the next 24 h. Failures included two out of 38 left-sided pathway procedures (5.3%), one out of 11 intermediate septal (9.1%) and four out of 22 right-sided pathway procedures (18.2%). These differences were not statistically significant. Average procedure and screening times for all procedures were 162.9 +/- 86.0 min and 56.8 +/- 48.2 min respectively, whereas the median of the number of discharges was 12, ranging from one to 51. There was no significant difference between pathway groups or between concealed and non-concealed pathways in respect to procedure and screening time or number of discharges. There was a significant tendency towards decreased procedure and screening times with accumulating experience and this was similar for all pathway groups. There was also a tendency towards improved cumulative success rates with time dedicated to procedures. We conclude that a certain amount of ablation experience is required, even by experienced electrophysiologists, before a relatively high success rate without long radiation exposure can be achieved, regardless of the location or the mode of conduction of the pathway.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiation exposure: Comparison of rapid exchange and conventional over‐the‐wire coronary angioplasty systems

The growth of coronary angioplasty has resulted in increased fluoroscopy time to patients, staff, and physicians. Rapid exchange-type catheters have purported to reduce fluoroscopy time and procedure time compared to conventional over-the-wire systems. Of 150 consecutive patients, 54 were treated solely with rapid-exchange catheters and 84 were treated solely with over-the-wire catheters. Excluding 12 cases treated with fixed wire or combination catheters, the following data were found: [table: see text] Overall procedural success was obtained in 98.5% (136/138) of patients, 1.5% (2) requiring emergency coronary artery bypass graft surgery. A significant 35% reduction in fluoroscopy time and 13% reduction in procedure time were found when rapid-exchange catheters were used, with identical success rates, number of balloons used per case, and complication rates compared to over-the-wire catheters. Rapid-exchange catheters should be considered as part of an overall effort to reduce radiation exposure in the interventional cardiology laboratory.