Radiation exposure of the operator during cardiac catheter ablation procedures

Non fluoroscopic ablation of different arrhythmic structures in an electrophysiology unit. Assessment of efficiency and security

BACKGROUND

Electroanatomical mapping systems (EMS) reduce fluoroscopy dose for the ablation. Higher costs and longer procedure times are the drawbacks associated with EMS. Our objective was to validate the efficiency of the EMS.

OBJECTIVE

To demonstrate that using EMS is more efficient and as secure as the traditional system of ablation.

METHODS

From April 2013 to June 2018, all patients were included into two groups, according to the intention of ablation with or without fluoroscopy. Right, left, supraventricular and ventricular ablation were included. We compared procedure variables (fluoroscopy, radiofrequency and procedure times, ablation results, complication rates and costs of the procedure) that included material and detrimental effect of fluoroscopy.

RESULTS

A total of 105 were included in the fluoroscopy group and 287 in the without fluoroscopy group. We found an important reduction in time and radiation dose in all the ablation procedures studied, without increasing the procedure time. No differences in ablation results nor complications rate were found. We found lower costs in the flutter ablation without fluoroscopy, similar costs in the right focal tachycardia ablation group and higher costs in the without fluoroscopy group for the AVNRT and left accessory pathway. When detrimental effect of fluoroscopy was added, all procedures without fluoroscopy were significantly more efficient than the ones performed with it.

CONCLUSIONS

Ablation without fluoroscopy is a technique as safe and effective as the conventional technique. Our study suggests that the radiation dose delivered to the patient and staff might be reduced, without increasing the total procedure time, being even more efficient.

Surgeon eye lens dose monitoring in catheterization lab: A multi-center survey: Invited for ECMP 2018 Focus Issue

PURPOSE

To perform a multi-centre survey on the eye lens equivalent dose absorbed by primary interventionalist during catheterization procedures, using a personal dosimeter placed close to the eye lens.

METHODS

15 different cardiologists working in 3 different centers, for a total of 5 operating rooms were enrolled. All of them were provided with a single thermoluminescent dosimeter positioned on the inner side of the temples of eyeglasses. The dose monitoring, performed on a two-months basis, started in 2016 and is still running. All dose measurements were performed by a ISO 17025 standard accredited dosimetry service thus providing certified uncertainties as well. Correlation of eye lens and wrist dose with KAP was also investigated.

RESULTS

A total number of 101 eye lens measurements were performed. Annual eye lens dose estimation was obtained for all 15 surgeons (mean, mode, range, standard deviation: 10.8, 8, 4.9-27.3, 5.6  mSv, respectively). Uncertainties on annual eye lens dose estimations ranged between 10% and 20%. No significant correlation was found between eye lens dose and KAP.

CONCLUSIONS

Cardiologists involved in catheterization procedures may receive annual eye lens doses close to the ICRP 118 dose limit and thus individual monitoring with a dedicated dosimeter should be carried out. Uncertainty assessment play a relevant role in eye lens equivalent dose estimation to ensure not to exceed dose limit.

Potential occupational exposures in diagnostic and interventional radiology: statistical modeling based on Finnish national dose registry data

BACKGROUND

Radiation worker categorization and exposure monitoring practices must be proportional to the current working environment.

PURPOSE

To analyze exposure data of Finnish radiological workers and to estimate the magnitude and frequency of their potential occupational radiation exposure, and to propose appropriate radiation worker categorization.

MATERIAL AND METHODS

Estimates of the probabilities of annual effective doses exceeding certain levels were obtained by calculating the survival function of a lognormal probability density function (PDF) fitted in the measured occupational exposure data.

RESULTS

The estimated probabilities of exceeding annual effective dose limits of 1 mSv, 6 mSv, and 20 mSv were in the order of 1:200, 1:10,000, and 1:500,000 per person, respectively.

CONCLUSION

It is very unlikely that the Category B annual effective dose limit of 6 mSv could even potentially be exceeded using modern equipment and appropriate working methods. Therefore, in terms of estimated effective dose, workers in diagnostic and interventional radiology could be placed into Category B in Finland. Current national personal monitoring practice could be replaced or supplemented using active personal dosimeters, which offer more effective means for optimizing working methods.

Reducing radiation exposure during procedures performed in the electrophysiology laboratory

INTRODUCTION

Expert societies recently published strong recommendations to reduce the exposure of patients and staff to ionizing radiation (IR) during interventional and electrophysiology (EP) procedures. However, adherence to these guidelines remains difficult and the impact of implementing such recommendations is poorly characterized.

METHODS AND RESULTS

We conducted a single-center cohort study to quantify radiation exposure over time in three EP laboratories at the Montreal Heart Institute during 5,546 consecutive procedures from 2012 to 2015 by 11 primary operators. Overall, 2,618 (47.2%) procedures were catheter-based and 2,928 (52.8%) were device interventions. Interventions to reduce radiation exposure included educational initiatives to raise awareness (i.e., limiting cine acquisition, patient position, table height), slower frame rate, lower radiation dose per pulse, collimation, and integration with 3-D mapping systems and/or MediGuide technology. An 85% reduction in IR exposure was observed from 2012 to 2015, with the mean dose-area-product (DAP) decreasing from 7.65 ± 0.05 Gy·cm² to 1.15 ± 0.04 Gy·cm² (P < 0.001). This was true for catheter-based procedures (mean DAP 16.99 ± 0.08 to 2.00 ± 0.06 Gy·cm² , P < 0.001) and device interventions (mean DAP 4.18 ± 0.06 to 0.64 ± 0.05 Gy·cm² , P < 0.001). The median effective dose of IR recorded per quarter by 282 cervical dosimeters on EP staff decreased from 0.57 (IQR 0.18, 1.03) mSv in 2012 to 0.00 (IQR 0.00, 0.19) mSv in 2015, P < 0.001.

CONCLUSION

Enforcing good clinical practices with simple measures and low-dose fluoroscopy settings are highly effective in reducing IR exposure in the EP lab. These promising results should encourage other EP labs to adopt similar protective measures.

Reduction of radiation exposure during atrial fibrillation ablation using a novel fluoroscopy image integrated 3-dimensional electroanatomic mapping system: A prospective, randomized, single-blind, and controlled study

OBJECTIVE

We explored whether the use of a novel fluoroscopy image integrated 3-dimensional electroanatomic mapping (F-EAM) system could result in a reduction of overall fluoroscopy time and radiation doses during the whole procedure of atrial fibrillation (AF) ablation.

METHODS

Eighty patients (44 men (55%); mean age 63 ± 10 years) who underwent catheter ablation due to paroxysmal AF were recruited consecutively in the present study. Patients were randomized (1:1) into 2 arms for AF ablation: one using a conventional 3-dimensional electroanatomical mapping (EAM) system and the other using the F-EAM system.

RESULTS

Fluoroscopy time (10:42 [interquartile range {IQR} 8:45-12:46] minutes:seconds vs 1:45 [IQR 1:05-2:22] minutes:seconds; P < .001) and radiation doses (2440 [IQR 1593-3091] cGy·cm(2) vs 652 [IQR 326-1489] cGy·cm(2); P < .001) in the EAM group were significantly greater than those in the F-EAM group. The majority of reduction of radiation exposure was achieved after transseptal puncture, which was near-zero fluoroscopic exposure. In total, approximately 84% of fluoroscopy time and 73% of radiation doses have been reduced during the AF ablation procedure using the F-EAM system compared to using the conventional EAM system. However, procedure time did not differ significantly (1:39 [IQR 1:18-2:10] hours:minutes vs 1:37 [IQR 1:17-1:50] hours:minutes; P = .362). During follow-up (5.9 ± 1.3 months), 61 patients (76.3%) had no recurrence of atrial arrhythmias. The recurrence rate between the 2 groups did not differ.

CONCLUSION

AF catheter ablation using the F-EAM system was safe and resulted in a significant reduction of radiation exposure to patients and staff without complicating the workflow of the procedure. A near-zero fluoroscopic catheter ablation procedure could be performed without compromising acute/mid-term efficacy and safety.

The Growing Culture Of A Minimally Fluoroscopic Approach In Electrophysiology Lab

Most of interventional procedures in cardiology are carried out under fluoroscopic imaging guidance. Besides other peri-interventional risks, radiation exposure should be considered for its stochastic (inducing malignancy) and deterministic effects on health (tissue reactions like erythema, hair loss and cataracts). In this article we analized the radiation risk from cardiovascular imaging to both patients and medical staff and discusses how customize the X-ray system and how to implement shielding measures in the cath lab. Finally, we reviewed the most recent developments and the latest findings in catheter navigation and 3D electronatomical mapping systems that may help to reduce patient and operator exposure.

Impact of respiration gating on image integration guided atrial fibrillation ablation

BACKGROUND

Radiofrequency (RF) catheter ablation guided by electroanatomic mapping systems is an effective therapy for atrial fibrillation. However, it may be affected by respiration movements. The aim of this study was to determine the impact of respiratory gating on procedural parameters in patients undergoing catheter ablation of atrial fibrillation (AF).

METHODS AND RESULTS

One-hundred forty consecutive patients undergoing pulmonary vein isolation were admitted to study. Respiratory gating module (AccuResp algorithm, Carto3, Biosense Webster) was enabled in 70 patients and disabled in 70 patients during procedures. Successful pulmonary vein isolation and sinus rhythm were obtained in all patients. A significant reduction in total procedure times [median 77, interquartile range (IQR 66-95) min vs median 82 (IQR 72-104) min, p < 0.05] and fluoroscopy times [median 14 (IQR 9-17) min vs median 16 (IQR 12-22) min, p < 0.05] were observed in the respiratory gated group. Although ablation times (duration between the first and last ablation) were significantly shorter in respiratory gated group [median 37 (IQR 32-53) min vs median 48 (IQR 39-65) min, p < 0.05], total RF application durations were not different between two groups [median 1,554 (IQR 1,213-2,196) s vs median 1,802 (IQR 1,344-2,448) s, p = 0.11]. Difference in electroanatomical map reconstruction times was not significant [median 14 (IQR 12-16) min in gated group vs median 13 (IQR 10-18) min in nongated group, p = 0.19].

CONCLUSION

Respiratory gating significantly improves fluoroscopy and ablation times during electroanatomic mapping guided AF ablation. Respiratory gated maps may provide uninterrupted continuous ablation applications. Furthermore, using automatic respiratory gating module does not prolong mapping times.