Significant Difference In Fluoroscopy Time Research Articles

Abstract 21364: Multicenter Prospective Study Comparing Phased Multipolar versus Traditional Radiofrequency Ablation

Background: Multipolar, phased radiofrequency (RF) catheter ablation (PVAC) has been associated with reduced procedural times compared to traditional RF. We performed a multicenter study to assess the efficacy and efficiency of using this catheter. Methods: This is a multicenter, sequential, prospective, cohort study between 2012 to 2016 in 6 tertiary care centers (NCT01562912). Patients were enrolled if they had symptomatic, paroxysmal AF (less than 7 days) refractory to at least one antiarrhythmic medication. Patients were enrolled in a 2:1 ratio of PVAC (group A) to control point-by-point RF with 3D mapping (group B). ECG and 48 hour Holter monitor were used to assess patients at 3, 6, 9 and 12 months post-ablation follow up. Recurrence was defined as any atrial arrhythmia >30 seconds excluding an initial 3 month blanking period. Results: Overall, 230 patients consisting of 162 males (70.4%) with mean age 57±11 years were analyzed. By Kaplan-Meier analysis, freedom from any atrial arrhythmia at 12 months was 49% and 69.2% in group A and B respectively (p=0.033) (Figure1). Among patients with recurrence, 14.7% (21) in group A and 7.7% (6) in group B had redo procedure within 12 month post procedure(p=0.12). Procedure time was significantly lower in Group A than Group B (P<0.0001). There was no significant difference in fluoroscopy time between the two groups (p=0.49). Stroke was not reported in any of the patients. Pulmonary Embolism, occurred in 1.3% of patients in group B. Pericardial effusion occurred in 1.4% in group A and 2.6% in group B. Tamponade occurred in 3.8% of patients in group B. Conclusion: This study demonstrated that the PVAC catheter is associated with significantly reduced procedure times for AF ablation, however, AF recurrence rates may be higher than contemporary point-by-point RF ablation with 3D mapping technology.

Fluoroscopy Learning Curve in Hip Arthroscopy—A Single Surgeon's Experience

To determine if (1) absorbed radiation dose and (2) fluoroscopy time decreased with experience over the first 100 cases of a single surgeon's hip arthroscopy practice. Subjects who underwent hip arthroscopy for symptomatic femoroacetabular impingement and labral injury were eligible for analysis. Inclusion criteria included the first 100 subjects who underwent hip arthroscopy by a single surgeon (December 2013 to December 2014). Subject demographics, procedure details, fluoroscopy absorbed dose (milligray [mGy]), and time were recorded. Subjects were categorized by date of surgery to one of 4 possible groups (25 per group). One-way analysis of variance was used to determine if a significant difference in dose (mGy) or time was present between groups. Simple linear regression analysis was performed to determine the relation between case number and both radiation dose and fluoroscopy time. Subjects underwent labral repair (n= 93), cam osteoplasty (n= 90), and pincer acetabuloplasty (n= 65). There was a significant (P < .001 for both) linear regression between case number and both radiation dose and fluoroscopy time. A significant difference in mGy was observed between groups, group 1 the highest and group 4 the lowest amounts of radiation (P= .003). Comparing individual groups, group 4 was found to have a significantly lower amount of radiation than group 1 (P= .002), though it was not significantly lower than that of group 2 (P= .09) or group 3 (P= .08). A significant difference in fluoroscopy time was observed between groups, group 1 the highest and group 4 the lowest times (P= .05). Comparing individual groups, group 4 was found to have a significantly lower fluoroscopy time than group 1 (P= .039). Correction for weight, height, and body mass index all revealed the same findings: significant (P < .05) differences in both dose and time across groups. The absorbed dose of radiation and fluoroscopy time decreased significantly over the first 100 cases of a single surgeon's hip arthroscopy practice learning curve. Level IV, therapeutic, retrospective, noncomparative case series.

A PROSPECTIVE, MULTICENTER COHORT STUDY COMPARING PHASED MULTIPOLAR VERSUS TRADITIONAL RADIOFREQUENCY ABLATION

Percutaneous catheter ablation has emerged as an effective therapeutic method for Atrial Fibrillation as the most common arrhythmia. Multipolar, phased radiofrequency (RF) catheter ablation (PVAC) has been shown to have comparable efficacy, and reduced fluoroscopy and procedural times compared to traditional RF. These studies have been small, therefore, we performed this multicenter cohort study in order to assess the efficacy and efficiency (procedural time and safety) of using this catheter for ablation in patients with highly symptomatic paroxysmal AF (PAF). This is a multicenter, sequential, prospective, cohort study between 2012 to 2016 in 6 tertiary care centers. The protocol of the study was registered on Clinicaltrials.gov website (NCT01562912). Patients were enrolled if they had symptomatic, paroxysmal AF (less than 7 days) refractory to at least one antiarrhythmic medication. A total of 230 patients were enrolled in a 2:1 ratio of PVAC (group A) to control (group B). Ablations were performed by the same operators. ECG and 48 hour Holter monitor were used to assess patients at 3, 6, 9 and 12 months post-ablation follow up. Recurrence was defined as any atrial arrhythmia >30 seconds. The primary endpoint was PVAC efficiency combining procedural time, efficacy, and repeat procedures. Intention to treat analysis was utilized for this study. Overall, 230 patients consisted of 162 males (70.4%) with mean age 57 ± 11 years were analyzed. Recurrence post ablation was 73.2% (101) and 58.9% (43) in groups A, and B respectively (p=0.034). Three, 6, 9, and 12-month recurrence for Group A versus B were 56.7% vs 49.3%, (p=0.31), 48.3% vs. 29.9%, (p=0.013), 44.3% vs 30.6, (p=0.07), and 35.2% vs 29.4%, (p=0.42) respectively. Among these patients, 14.7% (21) in group A and 7.7% (6) in group B had redo procedure (p=0.12). Procedure time was significantly lower in Group A than Group B (190.2±39.9 vs. 230±50.38 minutes, P < 0.0001). There was not any significant difference in fluoroscopy time between the two groups (p=0.49). Mean survival from recurrence for group A and B at 12 months was 26.8% vs 41.1% respectively (p=0.051). There were no significant differences in adverse events between the two groups in 12-month follow-up (P=0.16). This study demonstrated that PVAC catheter can significantly reduce procedure time for PVAI procedure, however, it may increase the likelihood of further recurrence of atrial tachyarrhythmia.

Randomized trial of cholangioscopy-guided laser lithotripsy versus conventional therapy for large bile duct stones (with videos)

Bile duct stones >1 cm have a decreased incidence of successful endoscopic extraction and often require lithotripsy. Although previous guidelines suggested mechanical lithotripsy for large common bile duct stones, current guidelines suggest cholangioscopy-guided lithotripsy as an adjunct with or without balloon dilation or mechanical lithotripsy. However, no randomized trials have assessed the usefulness of this practice. Patients with bile duct stones >1 cm in diameter were randomized in a 2:1 ratio to cholangioscopy-guided laser lithotripsy versus conventional therapy only. Conventional therapies such as mechanical lithotripsy or balloon dilation were also allowed in the laser lithotripsy group. Randomization was stratified by history of ERCP in the past 3 months. The primary outcome was endoscopic clearance of the bile duct stones. Endoscopic clearance was achieved in 39 (93%) of 42 patients treated with cholangioscopy-guided laser lithotripsy and 12 (67%) of 18 treated with conventional therapy only (P= .009). The 9 patients in whom ERCP was unsuccessful underwent surgical common duct exploration with stone removal. Mean procedure time was 120.7 ± 40.2 minutes for the cholangioscopy-guided laser lithotripsy group compared with 81.2 ± 49.3 minutes for the conventional therapy group (P= .0008). There was no significant difference in fluoroscopy time, number of procedures, or adverse events (cholangitis) (cholangioscopy, 2; conventional, 1) and post-ERCP pancreatitis (cholangioscopy, 2; conventional, 1). Cholangioscopy-guided laser lithotripsy increases the incidence of endoscopic clearance of large bile duct stones and decreases the need for surgery compared with conventional therapy alone. However, it is associated with longer procedure times. (Clinical trial registration number: NCT0175997.).

Abstract No. 273 - Comparison of fluoroscopic radiation exposure between chemoembolization and radioembolization: results from a prospective randomized study

The aim of this study is to compare radiation exposure related to fluoroscopy for patients undergoing conventional transarterial chemoembolization (cTACE) vs. yttrium-90 radioembolization (Y90) for Hepatocellular Carcinoma (HCC). With IRB approval, 45 patients with unresectable HCC were prospectively randomized to cTACE vs. Y90 [PREMIERE TRIAL (1)]. From this cohort, the fluoroscopy times and doses were recorded for all of these patients' procedures. Statistical comparison between both cohorts was conducted using independent sample t-test assuming unequal variances. Statistical significance was set at p<0.05. Twenty-one patients received cTACE (32 treatment sessions) and 24 patients received Y90 (29 treatment sessions) with glass microspheres. All Y90 patients had a separate planning angiogram prior to radioembolization. Mean fluoroscopic time (95%CI) for the planning angiography prior to Y90 was 11.6 minutes (9.3-14) and mean fluoroscopic dose was 1611 mGy (969–2253). Mean fluoroscopy time (95%CI) for Y90 treatment procedures was 13.3 minutes (10-16.5) and 18.3 minutes (15.5-21) for cTACE procedures (P = 0.021). Mean fluoroscopic dose (95%CI) for Y90 treatment was 1154 mGy (712–1596) and 1834 mGy (1356-2312) for cTACE (P = 0.035). Mean accumulative fluoroscopic time/dose for Y90 included the dose administered on planning angiography and on treatment day. Mean accumulative fluoroscopy time (95%CI) for cTACE patients after multiple treatments was 29 minutes (21-38) and 28 minutes for Y90 patients (24–33) (P = 0.8213). Mean fluoroscopic dose (95%CI) for Y90 patients was 2978 mGy (1933-4023) and 3941 mGy (1830-6053) for cTACE patients (P = 0.4). Y90 radioembolization exposes patients to significantly less fluoroscopy time and dose compared to cTACE per treatment session. When combined with planning angiography, there is no statistically significant difference in fluoroscopy time and dose between Y90 and cTACE.

The effect of body mass index on fluoroscopy time and radiation dose in intra-articular glenohumeral joint injections

PurposeTo determine the relationship between body mass index (BMI) and fluoroscopy time and radiation dose during fluoroscopy-guided glenohumeral joint injections. MethodsThis was a retrospective analysis of prospectively collected data. Physicians with board certification in Physical Medicine and Rehabilitation and/or Sports Medicine performed or supervised all injections. BMI was calculated within three months of the injection. Fluoroscopy time and radiation dose data were recorded by the fluoroscopy system and transcribed into the clinical database after each procedure. ResultsA total of 335 intra-articular GHJ injections were performed, 230 on the right shoulder and 105 on the left shoulder; none were bilateral. The mean fluoroscopy time for all injections was 18.8±12.6s, and the mean radiation DAP was 656±1190mGy-cm2. There was no significant difference in fluoroscopy time or dose between first-time and repeat injections (P=.405; P=.011) and no significant differences in fluoroscopy time or radiation dose when a trainee was involved (P=.756 for time and P=.149 for dose). Needle lengths of 1.5, 2.5, or 3.5in. were used during the injection, and there was no significant difference in needle length selection between BMI groups (P=.319). ConclusionsIntra-articular glenohumeral joint injection fluoroscopy time and radiation dose are not affected by body mass index, age, gender, trainee-involvement, first versus repeat injection, or needle length. This procedure is associated with a dose of radiation that likely has minimal to no clinical significance.

Abstract 13434: Relationship Between Fluoroscopy Time, Absorbed Dose And Effective Dose In A High-volume Electrophysiology Laboratory

Introduction: It is important to correctly quantify radiation exposure to assess the deterministic (tissue damage) and stochastic (cancer and genetic changes) risk associated with fluoroscopy use. Hypothesis: There is little correlation between fluoroscopy time and both the absorbed dose (AD; deterministic risk) and the effective dose (ED; stochastic risk) measured during EP procedures. Methods: A retrospective analysis of radiation dose data for subjects undergoing EP procedures in which fluoroscopy was used. Data collected included fluoroscopy time (min), dose area product (DAP - Gy*cm 2 ) and AD or air kerma (AK - mGy). The ED was calculated by multiplying DAP with a conversion factor of 0.20 mSv/(Gy*cm 2 ). Results: 3331 consecutive EP procedures were analyzed. Overall, the correlation between DAP/ED and AD is strong (r = 0.63, P &lt; .000001), while between fluoroscopy time and AD is moderate (r = 0.46, P &lt; .000001), and between fluoroscopy time and DAP/ED is weak (r = 0.26, P &lt; .000001). There were wide variations in dose and statistically significant differences in fluoroscopy time, DAP/ED, and AD depending on the nature of the procedure, with AF ablation conferring the highest values, followed by BIV implant, LAA exclusion and VT ablation procedures (Table). When considering AF ablation procedures, radiation exposure was found to be highly operator dependent (Figure). Conclusions: Fluoroscopy time does not correlate well with both ED and AD. Therefore, it shouldn’t be the sole indicator of radiation exposure reported for EP procedures, as it does not accurately reflect neither the stochastic nor the deterministic risk.

Introduction of a Team Based Approach to Radiation Dose Reduction in the Enhancement of the Overall Radiation Safety Profile of FEVAR

Fenestrated endovascular aneurysm repair (FEVAR) exposes operators and patients to considerable amounts of radiation. Introduction of fusion of three-dimensional (3D) computed tomography (CT) with intraoperative fluoroscopy puts new focus on advanced imaging techniques in the operating environment and has been found to reduce radiation and facilitate faster repair. The aim of this study is to evaluate the radiation dose effect of introducing a team-based approach to complex aortic repair. Procedural details for a cohort of 21 patients undergoing FEVAR after fusion-guided (Modern Group) imaging was introduced are compared with 21 patients treated in the immediate 12 months prior to implementation (Historic Group) at a centre with expertise in FEVAR. Non-parametric tests were used to compare procedure time (PT), air kerma, dose-area product (DAP), fluoroscopy time (FT), estimated blood loss (EBL) and pre- and post-operative estimated glomerular filtration rate (eGFR) between the groups. Change in operative approach resulted in a significant reduction in PT for the Modern group (median 285mins; interquartile range 268-322) compared with the Historic group (450mins; IQR 360-540 p=<0.001). There were reductions in skin dose for the Modern group (1.6Gy; IQR 1.09-2.1) compared with the Historic group (4.4Gy; 3.2-7.05 p=<0.001), and DAP (Modern 159Gy.cm2; IQR 123-226 vs 264.93Gy.cm2; 173.3-366.8 for Historic (p=0.006). There were no significant differences in FT, and pre- and post-operative eGFR between the two groups. Weight and height were distributed equally across both groups. Structured dose reports including the changes in frame rate were not available for analysis. Implementation of a team-based approach to radiation reduction significantly reduces radiation dose. These findings suggest that the radiation safety awareness that accompanies the introduction of fusion imaging may improve the overall radiation safety profile of FEVAR for patients and providers.

SU‐F‐I‐77: Radiation Dose in Cardiac Catheterization Procedures: Impact of a Systematic Reduction in Pulsed Fluoroscopy Frame Rate

Purpose:To evaluate whether one small systematic reduction in fluoroscopy frame rate has a significant effect on the total air kerma and/or dose area product for diagnostic and interventional cardiac catheterization procedures.Methods:The default fluoroscopy frame rate (FFR) was lowered from 15 to 10 fps in 5 Siemens™ Axiom Artis cardiac catheterization labs (CCL) on July 1, 2013. A total of 7212 consecutive diagnostic and interventional CCL procedures were divided into two study groups: 3602 procedures from 10/1/12 –6/30/13 with FFR of 15 fps; and 3610 procedures 7/1/13 – 3/31/14 at 10 fps. For each procedure, total air kerma (TAK), fluoroscopy skin dose (FSD), total/fluoroscopy dose area products (TAD, FAD), and total fluoroscopy time (FT) were recorded. Patient specific data collected for each procedure included: BSA, sex, height, weight, interventional versus diagnostic; and elective versus emergent.Results:For pre to post change in FFR, each categorical variable was compared using Pearson's Chi‐square test, Odds ratios and 95% confidence intervals. No statistically significant difference in BSA, height, weight, number of interventional versus diagnostic, elective versus emergent procedures was found between the two study groups. Decreasing the default FFR from 15 fps to 10 fps in the two study groups significantly reduced TAK from 1305 to 1061 mGy (p&lt;0.0001), FSD from 627 to 454 mGy (p&lt;0.0001), TAD from 8681 to 6991 uGy × m2(p&lt;0.0001), and FAD from 4493 to 3297 uGy × m2(p&lt;0.0001). No statistically significant difference in FT was noted. Clinical image quality was not analyzed, and reports of noticeable effects were minimal. From July 1, 2013 to date, the default FFR has remained 10 fps.Conclusion:Reducing the FFR from 15 to 10 fps significantly reduced total air kerma and dose area product which may decrease risk for potential radiation‐induced skin injuries and improve patient outcomes.

(471) The relationship between body mass index and fluoroscopy time during intra-articular hip injections: a multicenter cohort study

Hip pain is a common complaint and is often related to osteoarthritis (OA). When conservative management is ineffective for managing pain, intra-articular (IA) injections often with corticosteroid are typically performed. Ultrasound guidance during IA hip injection can be used in order to avoid radiation exposure; however, true IA injection cannot be confirmed without the use of contrast and fluoroscopy, and ultrasound guidance may be more challenging or impossible in patients with higher body mass index(BMI). Thus, fluoroscopic guidance is often used in obese patients. However, the relationship between BMI and fluoroscopy time during IA hip injections has not been investigated. The present study sought to define this relationship in retrospective cohort study at three outpatient pain centers. Median and standard deviation fluoroscopy time. Comparisons were made between body mass index categories of normal (18.5 - 24.9 kg/m2), overweight (25.0 - 29.9 kg/m2), and obese (≥30.0 kg/m2). Statistical significance was set at p=0.01 due to comparison of three groups. A total of 559 IA hip injections were analyzed. Patients had a mean age of 58 (standard deviation [SD] 14) years and 63% were female. There was no significant difference in fluoroscopy time when comparing BMI categories (p=0.02). However, when trainees were not involved in the injection, fluoroscopy times were significantly longer with increasing BMI, with obese patients requiring higher fluoroscopy time (p=0.01). The findings of this study indicate that fluoroscopy time during IA hip injection is increased with greater BMI, though this relationship is not present when trainees are involved due to comparatively longer fluoroscopy times in patients with lower BMI. Future study of the impact of BMI on radiation dose during fluoroscopically-guided IA hip injections is needed.

Puncture Reduction in Percutaneous Transforaminal Endoscopic Discectomy with HE's Lumbar LOcation (HELLO) System: A Cadaver Study.

BackgroundPercutaneous transforaminal endoscopic discectomy (PTED) usually requires numerous punctures under X-ray fluoroscopy. Repeated puncture will lead to more radiation exposure and reduce the beginners' confidence.ObjectiveThis cadaver study aimed to investigate the efficacy of HE’s Lumbar Location (HELLO) system in puncture reduction of PTED.Study designCadaver study.SettingComparative groups.MethodsHELLO system consists of self-made surface locator and puncture locator. One senior surgeon conducted the puncture procedure of PTED on the left side of 20 cadavers at L4/L5 and L5/S1 level with the assistance of HELLO system (Group A). Additionally, the senior surgeon conducted the puncture procedure of PTED on the right side of the cadavers at L4/L5 and L5/S1 level with traditional methods (Group B). On the other hand, an inexperienced surgeon conducted the puncture procedure of PTED on the left side of the cadavers at L4/L5 and L5/S1 level with the assistance of our HELLO system (Group C).ResultsAt L4/L5 level, there was significant difference in puncture times between Group A and Group B (P<0.001), but no significant difference was observed between Group A and Group C (P = 0.811). Similarly at L5/S1 level, there was significant difference in puncture times between Group A and Group B (P<0.001), but no significant difference was observed between Group A and Group C (P = 0.981). At L4/L5 level, there was significant difference in fluoroscopy time between Group A and Group B (P<0.001), but no significant difference was observed between Group A and Group C (P = 0.290). Similarly at L5/S1 level, there was significant difference in fluoroscopy time between Group A and Group B (P<0.001), but no significant difference was observed between Group A and Group C (P = 0.523). As for radiation exposure, HELLO system reduced 39%-45% radiation dosage when comparing Group A and Group B, but there was no significant difference in radiation exposure between Group A and Group C whatever at L4/L5 level or L5/S1 level (P>0.05). There was no difference in location time between Group A and Group B or Group A and Group C either at L4/L5 level or L5/S1 level (P>0.05).LimitationsSmall-sample preclinical study.ConclusionHELLO system was effective in reducing puncture times, fluoroscopy time and radiation exposure, as well as the difficulty of learning PTED. (2015-RES-127)

The Effect of Body Mass Index on Fluoroscopic Time and Radiation Dose During Sacroiliac Joint Injections

BackgroundSacroiliac joint (SIJ) injections are commonly performed under fluoroscopic guidance. Radiation exposure to patients and providers has not been comprehensively studied, particularly the effect of body mass index (BMI). ObjectiveTo identify whether patients with a larger BMI require longer fluoroscopy time or a larger radiation dose during performance of an SIJ injection. DesignRetrospective study of an academic institution database. SettingAcademic outpatient musculoskeletal clinic. PatientsAll patients who underwent SIJ injections during a 10-year period. Main Outcome MeasurementsMachine-reported fluoroscopic time and machine-reported radiation dose. A Bonferroni correction was implemented with P ≤ .01 as statistically significant. ResultsA total of 453 SIJ injections were performed in 359 patients. No statistically significant differences in fluoroscopy time were found between patients with BMI scores identified as normal, overweight, and obese (P = .054). However, the radiation doses were significantly greater for patients with higher BMI scores (χ2 [2, n = 441] = 62.4, P < .001); the median (interquartile range) doses were 1210 (839), 1671 (1240), and 2090 (2170) mGy-cm2 for normal weight, overweight, and obese patients, respectively. Although longer needles were used more often in obese patients (χ2 [2, n = 452] = 31.5, P < .001), fluoroscopy time was not associated with needle length (P = .162). No relationships were identified between fluoroscopy time and first-time (as opposed to repeat) injection (P = .123), trainee involvement (χ2 [1, n = 698] = 3.9, P = .049), or age (P = .337). ConclusionsPatients with an elevated BMI score who are undergoing SIJ injection receive an increased radiation dose despite equivalent fluoroscopic time. This finding suggests that the increased dose is likely due to x-ray output from the fluoroscope traversing a greater tissue mass, as opposed to the physician requiring more fluoroscopic images for proper needle placement. Fortunately, the increased radiation dose delivered to patients with a larger BMI score likely has negligible effects.

CTA with Fluoroscopy Image Fusion Guidance in Endovascular Complex Aortic Aneurysm Repair

To evaluate the effect of intraoperative guidance by means of live fluoroscopy image fusion with computed tomography angiography (CTA) on iodinated contrast material volume, procedure time, and fluoroscopy time in endovascular thoraco-abdominal aortic repair. CTA with fluoroscopy image fusion road-mapping was prospectively evaluated in patients with complex aortic aneurysms who underwent fenestrated and/or branched endovascular repair (FEVAR/BEVAR). Total iodinated contrast material volume, overall procedure time, and fluoroscopy time were compared between the fusion group (n=31) and case controls (n=31). Reasons for potential fusion image inaccuracy were analyzed. Fusion imaging was feasible in all patients. Fusion image road-mapping was used for navigation and positioning of the devices and catheter guidance during access to target vessels. Iodinated contrast material volume and procedure time were significantly lower in the fusion group than in case controls (159mL [95% CI 132-186mL] vs. 199mL [95% CI 170-229mL], p=.037 and 5.2 hours [95% CI 4.5-5.9 hours] vs. 6.3 hours (95% CI 5.4-7.2 hours), p=.022). No significant differences in fluoroscopy time were observed (p=.38). Respiration-related vessel displacement, vessel elongation, and displacement by stiff devices as well as patient movement were identified as reasons for fusion image inaccuracy. Image fusion guidance provides added value in complex endovascular interventions. The technology significantly reduces iodinated contrast material dose and procedure time.

Comparison of a Safety Strategy Using Transradial Access and Dual‐Axis Rotational Coronary Angiography with Transfemoral Access and Standard Coronary Angiography

We sought to investigate the radiation exposure and contrast utilization associated with using a strategy of transradial access and rotational angiography (radial-DARCA) compared to the traditional approach of transfemoral access and standard angiography (femoral-SA). There is an increased focus on optimizing patient safety during cardiac catheterization procedures. Professional guidelines have highlighted physician responsibility to minimize radiation doses and contrast volume. Dual axis rotational coronary angiography (DARCA) is the most recently investigated type of rotational angiography. This new technique permits complete visualization of the left or right coronary tree with a single injection, and is felt to reduce contrast and radiation exposure. A total of 56 consecutive patients who underwent radial-DARCA were identified. From the same time period, an age- and gender-matched group of 61 patients who had femoral-SA were selected for comparison. Total volume of contrast agent used, fluoroscopy time, and 2 measures of radiation dose (dose area product and air kerma) were recorded for each group. Mean contrast agent use and patient radiation exposure of the radial-DARCA group were significantly less than that of the femoral-SA group. There was no significant difference in fluoroscopy time between the 2 groups. Physicians can successfully employ an innovative safety strategy of transradial access combined with DARCA that is feasible and is associated with lower radiation doses and contrast volume than femoral artery access and traditional coronary angiography approach.

Real life results of ablation of atrial fibrillation in patients with hypertrophic cardiomyopathy. Outcome from the German Ablation registry

Introduction: Ablation is a standard option in the treatment of atrial fibrillation (AF). Patients with AF and hypertrophic cardiomyopathy (HCM) may represent a more difficult substrate for AF ablation. Hypothesis: Is ablation AF in patients with HCM as successful as in patients with lone AF? Methods: Patient and procedural data as well as acute and long-term outcome data from pts. with ablation of AF were prospectively collected in 55 centres. One-year follow-up (1yFU) data were gathered by telephone call. Data collection and the statistical analysis were performed for the German Ablation Registry organized. Results: In total, 63 pts. with HCM (71% men, mean age 57y, 70% complete follow-up) and 4437 pts. without structural heart disease (65% men, mean age 61y, 59% complete follow-up) underwent ablation for AF. Pts. with HCM had additional coronary artery disease in 11%, valvular heart disease in 9.5% and a reduced ejection fraction (<50%) in 27,8%. Pts. with HCM significantly more often suffered from paroxysmal AF (46% vs. 68,6% p<0,01). There was no difference with regard to the percentage of pts. undergoing the first ablation attempt (79,4% vs. 82,3% p=n.s.), acute procedural success (98,4% vs. 97,4% p=n.s.) or the recurrence rate of AF during 1yFU (45,2% vs. 46,9% p=n.s.) between HCM pts. and lone AF pts. Acute and long-term complication rates also did not differ significantly. The HCM pts. had a higher procedural duration (180 min vs. 165 min, p<0,05) but without a significant difference in fluoroscopy time (29.5 vs. 27.0 min, p=n.s.) and in the dose area product (4083 vs. 3298 cGy*cm2). Conclusions: These results from a multicentre registry based on real life data indicate that the ablation of AF in pts. with HCM can be performed with the same efficacy and safety as in pts. with lone atrial fibrillation. Limitations: Non randomized registry data - incomplete follow up (holter data).

Impact of access site selection and operator expertise on radiation exposure; a controlled prospective study

Published data relating to arterial access site selection and radiation exposure during coronary procedures suggest radial access may lead to increased radiation exposure, but this is based on poorly controlled studies. We sought to measure radiation exposure to patients and operators during elective coronary angiography (CA) according to access site, with other procedure related variables controlled for. We also investigated the specific effect of operator expertise in relation to radiation exposure. 100 consecutive patients undergoing first time elective CA were recruited prospectively. An expert transradial (TR) and an expert transfemoral (TF) operator performed 25 cases each via their default route. A trainee cardiologist with intermediate experience in both access sites performed 25 cases via each route. Angiographic projections were standardised and optimised radiation protection was utilised for all procedures. The primary endpoints were operator and patient exposure, quantified by effective dose (ED) and dose area product (DAP) respectively. Secondary endpoints included fluoroscopy time (FT) and time to patient ambulation. The trainee operator recorded higher values for radiation exposure in radial and femoral cases when compared to the expert operators. There were no significant differences in radiation exposure during CA to operator or patient according to access site when standardised by operator experience. For the trainee, ED for TR and TF procedures was 8.8 ± 4.3 μSv and 8.5 ± 6.5 μSv (P = .86) and DAP was 25.4 ± 4.8 Gycm(2) vs 25.2 ± 8.3 Gycm(2) (P = .9). For the expert TR and TF operators, ED was 6.4 ± 4.7 μSv vs 6.1 ± 5.6 μSv (P = .85) and DAP was 21.7 ± 6.5 Gycm(2) vs 22.4 ± 8.0 Gycm(2), (P = .74). There was no significant difference in FT in relation to access site. Time to ambulation was significantly longer with TF access. The use of TR access has no adverse effect on radiation exposure or FT for diagnostic CA, but does allow for quicker ambulation compared to TF access. The magnitude of radiation exposure is related to operator expertise for both access sites. The results of previous studies reflect the effect of uncontrolled patient and operator variables and not access site selection.

Abstract No. 342: Splenic salvage rate and radiation dose of proximal embolization compared to distal embolization in the blunt trauma patient

The purpose is to compare Proximal Splenic Embolization (PSE) to Distal Splenic Embolization (DSE) in terms of fluoroscopy time and splenic salvage rate to determine if either technique is advantageous in terms of radiation safety and/or outcome. The Trauma Registry and Interventional Radiology log books were cross-referenced from May 2002 until May 2011 to identify all trauma patients who underwent splenic arterial embolization. Patients were entered into a secure spreadsheet and the following information was recorded: medical record number, date of procedure, and fluoroscopy time. All cases were reviewed with an attending interventional radiologist and divided into one of two subgroups: PSE or DSE. The electronic medical record was then reviewed as far out as available to determine if the patient's spleen was subsequently removed. During the nine year interval of this retrospective cohort study, 35 patients were identified: 25 underwent PSE and 10 underwent DSE. The splenic salvage rate was 84% in the PSE group (21 of 25 patients) and 80% in the DSE group (2 of 10 patients). Fisher's Exact T-test was used to demonstrate a P value of 0.54 between the two groups. The average fluoroscopy time for the PSE group was 13 minutes 18 seconds. The average fluoroscopy time for the DSE group was 50 minutes 24 seconds. Non-parametric Kruskall-Wallis test (chi-square=11.3095) was used to demonstrate a P value of 0.008. These results demonstrate a statistically significant difference in fluoroscopy time between the two groups with no significant difference in splenic salvage rate, suggesting that in scenarios where neither technique is obviously indicated, PSE may be performed as efficaciously in terms of splenic salvage rate as DSE while reducing fluoroscopy time and thus procedure time and radiation dose to the patient and operating team. An additional benefit is that the trauma patient can then be more rapidly transferred to the ICU for stabilization and attention to other comorbidities. To our knowledge, this is the only study that directly compares both radiation dose and outcome between PSE and DSE.

Operator Radiation Exposure During Percutaneous Coronary Procedures Through the Left or Right Radial Approach

Background— Transradial percutaneous coronary procedures may be effectively performed through the right radial approach (RRA) or the left radial approach (LRA), but data on radiation dose absorbed by operators comparing the two approaches are lacking. The aim of the present study was to evaluate radiation dose absorbed by operators during coronary procedures through the RRA and LRA. Methods and Results— Three operators were equipped with 5 different dosimeters (left wrist, shoulder, thorax outside the lead apron, thorax under the lead apron, and thyroid) during RRA or LRA for coronary procedures. Each month, the dosimeters were analyzed to determine the radiation dose absorbed. From February to December 2009, 390 patients were randomly assigned to the RRA (185 patients; age, 66±11 years) or the LRA (185 patients; age, 66±11 years). There were no significant differences in fluoroscopy time (for RRA, 369 seconds; interquartile range, 134 to 857 seconds; for LRA, 362 seconds; interquartile range, 142 to 885 seconds; P =0.58) between the 2 groups. There were no significant differences in monthly radiation dose at the thorax (0.85±0.46 mSv for RRA and 1.12±0.78 mSv for LRA, P =0.33), at the thyroid (0.36±0.2 mSv for RRA and 0.34±0.3 mSv for LRA, P =0.87), and at the shoulder (0.73±0.44 mSv for RRA and 0.94±0.42 mSv for LRA, P =0.27). The dose at the wrist was significantly higher for the RRA (2.44±1.12 mSv) compared with the LRA (1±0.8 mSv, P =0.002). In both radial approaches, the thoracic radiation dose under the lead apron was undetectable. Conclusions— Compared with RRA, LRA for coronary procedures is associated with similar radiation dose for operators at the body, shoulder, or thyroid level, with a possible significant advantage at the wrist. The cumulative radiation dose for both approaches is well under to the annual dose-equivalent limit. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00282646.

Transradial approach (left vs right) and procedural times during percutaneous coronary procedures: TALENT study

most of the studies assessing transradial approach for coronary angiography (CA) have been performed through right radial approach (RRA). Our aim was to evaluate the safety and efficacy of left radial approach (LRA) compared with RRA for coronary procedures. from January 2009 to December 2009, in 2 hospitals, 1,540 patients were randomized to RRA (770 patients) or LRA (770 patients) for percutaneous coronary procedures. The primary end point was fluoroscopy time for CA and for percutaneous coronary intervention (PCI) evaluated independently. Prespecified subgroup analyses according to patient age and operator experience were planned. in 1,467 patients (732 RRA and 735 LRA), a CA (diagnostic group) was performed, and in 688 (344 each for RRA and LRA), a PCI. In the diagnostic group, LRA was associated with significantly lower fluoroscopy time (149 seconds, interquartile range [IQR] 95-270 seconds) and dose area product fluoroscopy (10.7 Gy cm(2), IQR 6-20.5 Gy cm(2)) compared with the RRA (168 seconds, IQR 110-277 seconds, P = .0025 and 12.1 Gy cm(2), IQR 7-23.8 Gy cm(2), P = .004, respectively). In the PCI group, there were no significant differences in fluoroscopy time (614 seconds, IQR 367-1,087 seconds for LRA and 695 seconds, IQR 415-1,235 seconds, P = .087 for RRA) and dose area product fluoroscopy (53.7 Gy cm(2), IQR 29-101 Gy cm(2) for LRA and 63.1 Gy cm(2), IQR 31-119 Gy cm(2), P = .17 for RRA). According to subgroup analyses, the differences between LRA and RRA were confined to older patients (≥ 70 years old) and to operators in training. left radial approach for coronary diagnostic procedures is associated with lower fluoroscopy time and radiation dose adsorbed by patients compared with the RRA, particularly in older patients and for operators in training.

Pediatric Radiation Exposure and Effective Dose Reduction during Voiding Cystourethrography

To compare radiation exposure and effective dose in children who underwent voiding cystourethrography (VCUG) performed with grid-controlled variable-rate pulsed fluoroscopy (GCPFL) with radiation exposure and effective dose in children who underwent VCUG performed with continuous fluoroscopy (CFL) and to compare these effective doses with those estimated with radionuclide cystography (RNC). Institutional review board approval was obtained, and the informed consent requirement was waived for this HIPAA-compliant retrospective study. Radiation exposure and fluoroscopy time during VCUG were reviewed in 145 children (75 girls, 70 boys; age range, 3 days to 8 years) who underwent GCPFL or CFL between 2001 and 2002. Children were grouped on the basis of the fluoroscopy unit used and their supine anteroposterior abdominal diameter (group 1, 8.0-8.5-cm diameter; group 2, 10-11-cm diameter; group 3, 12-13-cm diameter). Analysis of variance was used to compare radiation exposure and fluoroscopy time between fluoroscopy units and patient diameter groups. Effective doses were calculated and compared for both fluoroscopes and for estimated RNC dose values. GCPFL resulted in a significant reduction in total radiation exposure, which was at least eight times lower than that with CFL in all three groups (P < .001 for all). There was no significant difference in fluoroscopy time (P > .50). Effective radiation doses from GCPFL were approximately one order of magnitude lower than those from CFL but one order of magnitude higher than those from RNC. In children, VCUG can be performed with a GCPFL unit that delivers radiation exposures that are at least eight times lower than those delivered by a conventional CFL unit. http://radiology.rsnajnls.org/cgi/content/full/2492062066/DC1.