Occupational health hazards in the interventional laboratory: time for a safer environment

Comprehensive radiation shield minimizes operator radiation exposure in coronary and structural heart procedures

OBJECTIVES

This study evaluated the efficacy of a novel comprehensive shield designed to minimize radiation exposure (RE) to Physicians performing coronary and structural heart procedures.

BACKGROUND

The Protego™ radiation shielding system (Image Diagnostics Inc., Fitchburg, Ma) is designed to provide comprehensive protection from RE and has been State certified sufficient to allow operators to perform procedures without orthopedically burdensome lead aprons.

METHODS

This single center two-group cohort study assessed the efficacy of this shield in a large number of cardiac procedures (coronary and structural), comparing operator RE compared to standard protection methods (personal lead apparel and "drop down" shield).

RESULTS

The Protego™ system reduced operator RE by 99 % compared to Standard Protection. RE was significantly lower at both "Head" level by thyroid median dose 0.0 (0.0, 0,0) vs 5.7 (2.9, 8.2) μSv (p < 0.001), as well as waist dose 0.0 (0.0, 0.0) vs 10.0 (5.0, 16.6) μSv (p < 0.001). "Zero" Total RE was documented by Raysafe™ in 64 % (n = 32) of TAVR cases and 73.2 % (n = 183) of the coronary cases utilizing Protego™. In contrast, standard protection did not achieve "Zero" exposure in a single case. These dramatic differences in RE were achieved despite higher fluoroscopy times in the Protego™ arm (11.9 ± 8.6 vs 14.3 ± 12.5 min, p = 0.015). Per case procedural exposure measured by Dose Area Product was higher in the Protego™ group compared to standard protection (115.4 ± 139.2 vs 74.9 ± 69.3, p < 0.001).

CONCLUSION

The Protego™ shield provides total body RE protection for operators performing both coronary and structural heart procedures. This shield allows procedural performance without the need for personal lead aprons and has potential to reduce catheterization laboratory occupational health hazards.

Comprehensive Shielding System Enhances Radiation Protection for Structural Heart Procedures

Background

This study of radiation exposure (RE) to physicians performing structural heart procedures evaluated the efficacy of a novel comprehensive radiation shield compared to those of traditional shielding methods. A novel comprehensive shielding system (Protego, Image Diagnostics Inc) has been documented to provide superior RE protection during coronary procedures compared to that provided by a standard "drop down" shield. The purpose of this study was to assess the efficacy of this shield in transcatheter aortic valve replacement (TAVR) procedures, which are associated with disproportionate RE to operators.

Methods

This single-center, 2-group cohort, observational analysis compared RE to the primary physician operator performing TAVR using the Protego shield (n = 25) with that using a standard drop-down shield with personal leaded apparel (n = 25). RE was measured at both thyroid and waist levels with a real-time dosimetry system (RaySafe i3, RaySafe) and was calculated on a mean per case basis. Data were collected on additional procedural parameters, including access site(s) for device implantation, per case fluoroscopy time, air kerma, and patient factors, including body mass index. Between-group comparisons were conducted to evaluate RE by group and measurement sites.

Results

The Protego system reduced operator RE by 99% compared to that using standard protection. RE was significantly lower at both the thyroid level (0.08 ± 0.27 vs 79.2 ± 62.4 μSv; P < .001) and the waist level (0.70 ± 1.50 vs 162.0 ± 91.0 μSv, P < .001). "Zero" total RE was documented by RaySafe in 60% (n = 15) of TAVR cases using Protego. In contrast, standard protection did not achieve zero exposure in a single case.

Conclusions

The Protego shield system provides superior operator RE protection during TAVR procedures. This shield allows operators to work without the need for personal lead aprons and has potential to reduce catheterization laboratory occupational health hazards.

An In-depth Analysis of the Adverse Effects of Ionizing Radiation Exposure on Cardiac Catheterization Staffs

Diagnostic and interventional angiograms are instrumental in the multidisciplinary approach to CAD management, enabling accurate diagnosis and effective targeted treatments that significantly enhance patient care and cardiovascular outcomes. However, cath lab staff, including interventional cardiologists, is consistently exposed to ionizing radiation, which poses inherent health risks. Radiation exposure in the cath lab primarily results from the use of fluoroscopy and cineangiography during diagnostic and interventional procedures. Understanding these risks and implementing effective radiation protection measurements are imperative to ensure the well-being of healthcare professionals while delivering high-quality cardiac care. Prolonged and repeated exposure can lead to both deterministic and stochastic effects. Deterministic effects, such as skin erythema and tissue damage, are more likely to occur at high radiation doses. Interventional cardiologists and staff may experience these effects when safety measures are not rigorously followed. In fact, while ionizing radiation is essential in the practice of radiation cardiology ward, cath lab staff faces inherent risks from radiation exposure. Stochastic effects, on the other hand, are characterized by a probabilistic relationship between radiation exposure and the likelihood of harm. These effects include the increased risk of cancer, particularly for those with long-term exposure. Interventional cardiologists, due to their frequent presence in the cath lab, face a higher lifetime cumulative radiation dose, potentially elevating their cancer risk. Protective measures, including the use of lead aprons, thyroid shields, and radiation monitoring devices, play a crucial role in reducing radiation exposure for cath lab personnel. Adherence to strict dose optimization protocols, such as minimizing fluoroscopy time and maximizing distance from the radiation source, is also essential in mitigating these risks. Ongoing research and advancements in radiation safety technology are essential in further for minimizing the adverse effects of ionizing radiation in the cath lab.

A novel comprehensive radiation shielding system eliminates need for personal lead aprons in the catheterization laboratory

OBJECTIVES

This clinical study evaluated the efficacy of a novel radiation shielding system for the cardiac catheterization laboratory designed to provide comprehensive protection that obviates the need for personal lead aprons.

BACKGROUND

Invasive Cardiologists are exposed to occupational health hazards related directly to radiation exposure (RE) and indirectly to the orthopedic burden of wearing only partially protective lead aprons. Innovations to reduce these risks are warranted. A novel comprehensive shielding system (Protego^TM , Image Diagnostics Inc, Fitchburg, Ma) has been validated in pre-clinical studies to provide excellent radiation protection, sufficient for the State of Michigan to certify it for use without need for personal lead aprons.

METHODS

This clinical analysis measured RE to a single Physician operator utilizing the Protego^TM shield (and not wearing personal lead apron) during routine cardiac catheterization procedures (diagnostic and interventional). RE was measured at both thyroid and waist level with a real-time dosimetry system (Raysafe^TM , Billdal, Sweden), calculated on a median per case basis (mrems). Additional parameters collected included procedure type, access site, per case fluoroscopy time, and patient factors including body mass index.

RESULTS

In n=98 cases (25% diagnostic, 75% interventional including 22% chronic total occlusions), median/case RE was 0.4 mrems (thyroid) and 0.2 mrems (waist). RE=0 in 12 cases. In no case did radiation exposure exceed 3.2 mrems.

CONCLUSION

The Protego^TM shield system provides excellent RE protection to the Physician operator, without the need for personal lead aprons and has the potential to reduce catheterization laboratory occupational health hazards.

Kinetics Analysis and ADRC-Based Controller for a String-Driven Vascular Intervention Surgical Robotic System

Vascular interventional surgery is a typical method for diagnosing and treating cardio-cerebrovascular diseases. However, a surgeon is exposed to significant X-radiation exposure when the operation is conducted for a long period of time. A vascular intervention surgical robotic system for assisting the surgeon is a promising approach to address the aforementioned issue. When developing the robotic system, a high displacement accuracy is crucial, and this can aid in enhancing operating efficiency and safety. In this study, a novel kinetics analysis and active disturbance rejection control (ADRC)-based controller is proposed to provide high accuracy for a string-driven robotic system. In this controller, kinetics analysis is initially used to improve the accuracy affected by the inner factors of the slave manipulator. Then, the ADRC controller is used to further improve the operating accuracy of the robotic system. Finally, the proposed controller is evaluated by conducting experiments on a vascular model. The results indicate maximum steady errors of 0.45 mm and 6.67°. The experimental results demonstrate that the proposed controller can satisfy the safety requirements of the string-driven robotic system.

Evaluating the physical, psychosocial and ergonomic burden of lead aprons among Jordanian interventionists: a nationwide study

Objectives. This study assessed the physical and psychological burden of lead apron use on Jordanian interventionists and investigated the attitudes and knowledge of interventional personnel toward ergonomic guidelines and practices. Methods. A cross-sectional investigation of a randomly sampled Jordanian cohort of interventional personnel was conducted using a self-administered questionnaire.

Results. A nationwide sample of 130 practitioners with a mean 9.3 ± 8.1 years of experience in interventional procedures participated. Practitioners were aware of their apron's weight but not of its lead equivalence (71.5%). More than 60% of respondents complained of back pain. While 66.9% did not develop musculoskeletal pathologies, 64.3% of those with already established musculoskeletal pathologies experienced worse pain due to apron usage. Despite believing in the effect of lead aprons on muscular strain and work performance, 78.5% adhere to its usage. In terms of ergonomics, only 39.2% were aware of ergonomic guidelines; however, 90.0% believe that ergonomic practices are essential as 49.2% have experienced discomfort due to bad ergonomics. In terms of psychological burden, anxiety and depression were suggested in 16.4 and 21.6% of the sample.

Conclusion. Jordanian interventionists portray positive attitudes toward lead aprons; nevertheless, their awareness of ergonomic practices warrants the implementation of evidenced-based interventions.

Occupational radiation exposure in doctors: an analysis of exposure rates over 25 years

OBJECTIVES

Healthcare professionals' occupational exposure to ionising radiation may be increasing due to increasing use of imaging and image-guided intervention. This study aims to assess the occupational exposure of doctors over a 25-year period at an NHS teaching hospital.

METHODS

Dosemeter measurements were collected prospectively from 1995 to 2019. Two retrospective analyses were performed over time (first including all measurements, second excluding "zero-dose" measurements), and by speciality. Group comparisons were undertaken using multilevel linear regression; a p-value <0.05 was deemed significant.

RESULTS

8,892 measurements (3,983 body, 1,514 collar, 649 eye, 2,846 hand), of which 3,350 were non-zero measurements (1,541 body, 883 collar, 155 eye, 771 hand), were included. Whole dataset analysis found a significant decrease in exposure for radiologists and cardiologists, as measured by body, hand and collar dosemeters over the last 25 years (p < 0.01 for all). The non-zero readings reflect the whole cohort analysis except in the case of eye dosemeters, which showed a significant decrease in exposure for cardiologists (p < 0.01), but a significant increase for radiologists and surgeons/anaesthetists (p < 0.01 for both).

CONCLUSIONS

Whilst ionising radiation remains an occupational risk for doctors, the overall decreasing trend in occupational exposure is reassuring. However, a significant rise in eye dose for radiologists, surgeons and anaesthetists is concerning, and close monitoring is required to prevent future issues.

ADVANCES IN KNOWLEDGE

This paper is one of few evaluating the occupational radiation exposure to doctors over a 25-year period, showing that although most dosemeter measurements reflect decreasing exposure, the increase in eye exposure warrants caution.

Enhancing occupational safety in the X-ray laboratory

Despite more than 80% of interventional operators reporting one or more orthopedic injuries attributed to the X-ray laboratory, there has been limited adoption of various strategies and equipment to minimize these injuries. A comprehensive review of these methods to reduce musculoskeletal strain is lacking in the current literature, and is essential in order to ensure a long, healthy, and productive interventional career.

A novel catheterization laboratory radiation shielding system: Results of pre-clinical testing

BACKGROUND

This pre-clinical study evaluated the efficacy of a novel shielding system to reduce scatter radiation in the cardiac catheterization laboratory.

METHODS

Using a scatter radiation phantom in a standard cardiac catheterization laboratory, a radiation physicist recorded radiation measurements at 20 reference points on the operator side of the table. Measurements were made with fluoroscopy and cine with the C-arm in the posterior-anterior (PA) and 40 degrees left anterior oblique (LAO) orientations. Scatter radiation doses were compared with and without use of the shielding system.

RESULTS

Use of the shielding system was associated with >94.2% reduction in scatter radiation across all reference points in the PA and LAO projections with fluoroscopy and cine. With the shielding system, dose reductions at the location of the primary operator ranged from 97.8% to 99.8%. At locations of maximum scatter radiation, use of the shielding system resulted in dose reductions ranging from 97.8% to 99.8% with fluoroscopy and from 97.9% to 99.8% with cine.

CONCLUSIONS

In this pre-clinical study, a novel radiation shielding system was observed to dramatically reduce scatter radiation doses. Based on these results, clinical testing is warranted to determine whether the shielding system will enable operators and staff to perform interventional procedures with less radiation exposure that may obviate the need to wear standard lead apparel.

INDEXING WORDS

Radiation safety; occupational health; occupational hazard.

[Assessment of the practices and knowledge among cardiologists regarding radiation protection in Tunisia]

Introduction

les procédures de cardiologie interventionnelle sont devenues complexes et chronophages avec un sur-risque d´exposition aux rayonnements ionisants. L’objectif de notre étude était d’évaluer le niveau des connaissances et des pratiques en radioprotection des cardiologues Tunisiens exposés au rayon X.

Méthodes

notre étude est descriptive analytique réalisée en octobre 2019, organisée sous forme de questionnaire anonyme des connaissances et pratiques en radioprotection et envoyé à tous les Cardiologues Tunisiens exposés aux rayons X.

Résultats

parmi 126 cardiologues exposés aux rayons X et ayant reçu le questionnaire, 58 médecins ont répondu au questionnaire (48%), avec une prédominance masculine (72%, n=42). Trente-huit médecins (65%) exerçaient dans le secteur public. L´expérience professionnelle était en moyenne de 12,02 ans (ET 6,88 ans). La moitié des médecins avaient un score de connaissances inférieur à 50%. La moyenne du score des pratiques était de 43,83 (ET 13,95%). Le port du tablier en plomb, de la cache thyroïde, du dosimètre, des lunettes en plomb, du calot en plomb était respectivement de 100% (n=58), 86,2% (n=50), 30,7% (n=18), 12,1% (n=7) et 1,7% (n=1). Il n´y avait pas de corrélation entre les scores et l´âge du médecin ainsi que la durée de l´expérience professionnelle. Les scores de connaissances ne différaient pas statistiquement entre les 2 sexes (p=0,06) ni entre le secteur public et le secteur privé (p=0,9). Le score de pratique était significativement plus élevé chez les hommes (0.007) et les cardiologues interventionnels comparés aux rythmologues et cardiopédiatres (p<0.001).

Conclusion

le niveau des connaissances et des pratiques des cardiologues Tunisiens en radioprotection est globalement insuffisant. Ce qui interpelle les autorités sanitaires à organiser un plan de formation régulier pour cette population.

Gender Issues in Italian Catheterization Laboratories: The Gender-CATH Study

Background Women represent an increasing percentage of interventional cardiologists in Italy compared with other countries. However, gaps exist in understanding and adapting to the impact of these changing demographics. Methods and Results We performed a national survey to analyze demographics, gender-based professional difference, needs in terms of catheterization laboratory (Cath-Lab) abstention, and radiation safety issues in Italian Cath-Lab settings. A survey supported by the Italian Society of Interventional Cardiology (Società Italiana di Cardiologia Interventistica-Gruppo Italiano di Studi Emodinamici SICI-GISE) was mailed to all SICI-GISE members. Categorical data were compared using the χ2 test. P<0.05 was considered significant. There were 326 respondents: 20.2% were <35 years old, and 64.4% had >10 years of Cath-Lab experience. Notably, 26.4% were women. Workload was not gender-influenced (women performed "on-call" duty 69.8% versus men 68.3%; P=0.97). Women were more frequently unmarried (22.1% women versus 8.7% men; P=0.002) and childless (43.9% versus 56.1%; P<0.001). Interestingly, 69.8% of women versus 44.6% of men (P<0.001) argued that pregnancy/breastfeeding negatively impacts professional skill development and career advancement. For Cath-Lab abstention, 38.9% and 69.6% of respondents considered it useful to perform percutaneous coronary intervention robotic simulations and "refresh-skill" sessions while they were absent or on return to work, respectively, without gender differences. Overall, 80% of respondents described current radioprotection counseling efforts as inadequate and not gender specific. Finally, 26.7% faced some type of job discrimination, a significantly higher proportion of whom were women. Conclusions Several gender-based differences exist or are perceived to exist among interventional cardiologists in Italian Cath-Labs. Joint strategies addressing Cath-Lab abstention and radiation exposure education should be developed to promote gender equity in interventional cardiologists.

Radiation Exposure Reduction in Ultrasound-Guided Transforaminal Percutaneous Endoscopic Lumbar Discectomy for Lumbar Disc Herniation: A Randomized Controlled Trial

BACKGROUND

Transforaminal percutaneous endoscopic lumbar discectomy (TF-PELD) is a minimally invasive technique with high radiation exposure. The purpose of this study was to compare radiation exposure of ultrasound-guided TF-PELD with fluoroscopy-guided TF-PELD.

METHODS

In this prospective randomized controlled clinical trial, 60 patients with lumbar disc herniation were enrolled and randomly assigned to 2 groups (30 cases in each group): the ultrasound-guided group or the fluoroscopy-guided group. The radiation exposure, fluoroscopy time, and visual analog scale score were recorded. The number of possible operations per year within the yearly occupational exposure limit (OEL) was calculated. We also recorded the adverse events to evaluate the safety of ultrasound-guided TF-PELD.

RESULTS

In 30 patients from the ultrasound-guided group, the lumbar disc structure was clearly visible under ultrasound guidance. The effective dose to surgeons and radiation dose to patients were 1.7 ± 0.4 and 25.2 ± 4.9 μSv in the ultrasound-guided group and 9.0 ± 2.5 and 127.4 ± 27.1 μSv in the fluoroscopy-guided group (P < 0.05), respectively. The fluoroscopy time was 2.6 ± 0.5 seconds in the ultrasound-guided group and 127.3 ± 29.5 seconds in the fluoroscopy-guided group (P < 0.05). A surgeon with shielding devices could treat 5556 cases per year in the fluoroscopy-guided group before exceeding the OEL for whole-body radiation, whereas they could treat 29,412 cases in the ultrasound-guided group. No difference between groups was detected in postoperative visual analog scale score (P > 0.58). No serious adverse event was found in any patient.

CONCLUSIONS

Ultrasound-guided TF-PELD could decrease radiation exposure to surgeons and patients, without serious adverse events. It seems to be an acceptable alternative to fluoroscopy-guided TF-PELD.

Simple preoperative radiation safety interventions significantly lower radiation doses during central venous line placement in children

PURPOSE

The purpose of this study was to reduce radiation exposure during pediatric central venous line (CVL) placement by implementing a radiation safety process including a radiation safety briefing and a job-instruction model with a preradiation time-out.

METHODS

We reviewed records of all patients under 21 who underwent CVL placement in the operating room covering 22 months before the intervention through 10 months after 2013-2016. The intervention consisted of a radiation safety briefing by the surgeon to the intraoperative staff before each case and a radiation safety time-out. We measured and analyzed the dose area product (DAP), total radiation time pre- and postintervention, and the use of postprocedural chest radiograph.

RESULTS

100 patients with valid DAP measurements were identified for analysis (59 preintervention, 41 postintervention). Following implementation of the radiation safety process, there was a 79% decrease in median DAP (61.4 vs 13.1 rad*cm², P < 0.001) and a 73% decrease in the median radiation time (28 vs 7.6 s, P < 0.001). Additionally, there was a significant reduction in use of confirmatory CXR (95% vs 15%, P < 0.01).

CONCLUSION

A preoperative radiation safety briefing and a radiation safety time-out supported by a job-instruction model were effective in significantly lowering the absorbed doses of radiation in children undergoing CVL insertion.

TYPE OF STUDY

Case-control study.

LEVEL OF EVIDENCE

Level III.

Usefulness of Pelvic Radiation Protection Shields During Transfemoral Procedures-Operator and Patient Considerations

Interventional cardiologists are increasingly exposed to radiation-induced hazards. The MAVIG shield is a lead-free drape and the RADPAD is a sterile, disposable, and lead-free shield, placed on the patient with the aim to minimize operator-received scatter radiation. The objective of the trial was to examine their efficacy in a real-world situation. We randomized 125 patients who underwent coronary procedures from the right femoral artery into 3 groups: Control group (n = 48 [39%]) without additional protection, MAVIG lead shield (n = 38 [30%]) and RADPAD shield (n = 39 [31%]). Multiple radiation dosimeters were used in each case. All 3 groups were with similar baseline and procedural characteristics. Fluoroscopy time and number of views were similar in all 3 study groups. Compared with the standard (no shield) protection [3.5 ± 5.57 mSv], the scatter radiation was reduced by a factor of 5 for the MAVIG group [0.46 ± 1.6 mSv and p = 0.001] and a factor of 4 for the RADPAD group [1.16 ± 2.29 mSv and p = 0.01]. The physician's radiation decreased with the 2 shields, but only the MAVIG shield showed statistically significant lower radiation: 0.49 ± 0.42 mSv in the standard group versus 0.26 ± 0.3 mSv in the MAVIG and 0.35 ± 0.44 mSv in the RADPAD (p = 0.135 for RADPAD and p = 0.005 for MAVIG). Patient's exposure was statistically similar to the control group. Although numerically there was an increase in radiation with the RADPAD and decrease with the MAVIG.

CONCLUSIONS

Our study found no statistically increase in patient radiation while the operator's radiation exposure was reduced. Decreasing scatter radiation can be done effectively using simple measurements and is of major importance.

Compensatory force measurement and multimodal force feedback for remote-controlled vascular interventional robot

Minimally invasive vascular interventional surgery is widely used and remote-controlled vascular interventional surgery robots (RVIRs) are being developed to reduce the occupational risk of the intervening physician in minimally invasive vascular interventional surgeries. Skilled surgeon performs surgeries mainly depending on the detection of collisions. Inaccurate force feedback will be difficult for surgeons to perform surgeries or even results in medical accidents. In addition, the surgeon cannot quickly and easily distinguish whether the proximal force exceeds the safety threshold of blood vessels or not, and thus it results in damage to the blood vessels. In this paper, we present a novel method comprising compensatory force measurement and multimodal force feedback (MFF). Calibration experiments and performance evaluation experiments were carried out. Experimental results demonstrated that the proposed method can measure the proximal force of catheter/guidewire accurately and assist surgeons to distinguish the change of proximal force more easily. This novel method is suitable for use in actual surgical operations.

Operation evaluation in-human of a novel remote-controlled vascular interventional robot

Remote-controlled vascular interventional robots (RVIRs) are being developed to increase the accuracy of surgical operations and reduce the number of occupational risks sustained by intervening physicians, such as radiation exposure and chronic neck/back pain. However, complex control of the RVIRs improves the doctor's operation difficulty and reduces the operation efficiency. Furthermore, incomplete sterilization of the RVIRs will increase the risk of infection, or even cause medical accidents. In this study, we introduced a novel method that provides higher operation efficiency than a previous prototype and allows for complete robot sterilization. A prototype was fabricated and validated through laboratory setting experiments and an in-human experiment. The results illustrated that the proposed RVIR has better performance compared with the previous prototype, and preliminarily demonstrated that the proposed RVIR has good safety and reliability and can be used in clinical surgeries.

A cooperation of catheters and guidewires-based novel remote-controlled vascular interventional robot

Remote-controlled vascular interventional robots (RVIRs) are being developed to increase the overall accuracy of surgical operations and reduce the occupational risks of intervening physicians, such as radiation exposure and chronic neck/back pain. Several RVIRs have been used to operate catheters or guidewires accurately. However, a lack of cooperation between the catheters and guidewires results in the surgeon being unable to complete complex surgery by propelling the catheter/guidewire to the target position. Furthermore, it is a significant challenge to operate the catheter/guidewire accurately and detect their proximal force without damaging their surfaces. In this study, we introduce a novel method that allows catheters and guidewires to be operated simultaneously in complex surgery. Our method accurately captures force measurements and enables precisely controlled catheter and guidewire operation. A prototype is validated through various experiments. The results demonstrate the feasibility of the proposed RVIR to operate a catheter and guidewire accurately, detect the resistance forces, and complete complex surgical operations in a cooperative manner.

The Amigo™ Remote Catheter System: From Concept to Bedside

Radiation exposure is a serious concern during fluoroscopic procedures, including electrophysiology (EP) studies and radiofrequency catheter ablation of arrhythmias. Operators typically don lead aprons to protect themselves from radiation, but wearing lead can result in greater fatigue and orthopedic injury during long procedures. To address this problem, two robotic catheter systems (RCS) have previously been introduced on the market, the Niobe^® (Stereotaxis Inc., St. Louis, MO, USA) and Sensei^® X (Hansen Medical, Inc., Mountain View, CA, USA) systems. However, the widespread adoption of these systems has been limited by both cost and ease of use. In contrast, the Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) was developed to provide a simple, lower profile, and less expensive remote catheter manipulation solution. Approved by the United States Food and Drug Administration (FDA), this technology allows for operators to remotely manipulate electrophysiology (EP) catheters from outside the fluoroscopy field. Notably, the Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) first underwent an early study in dogs in 2008 to demonstrate its safety and efficacy in an animal model. After a clinical trial evaluating its safety and mapping capabilities in humans was completed in 2010, the Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) underwent several scientific studies to examine its ability to assist in the mapping and ablation of various arrhythmias in comparison with the conventional manual approach. The Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) achieved mapping and ablation success rates that were similar to those achieved with manual catheter manipulation, and no complications due to its use were observed. It was approved by the FDA for use in diagnostic EP studies of the right atrium and ventricle in 2012, with this indication later expanded in 2014 to include radiofrequency ablations. The device is currently compatible with the Blazer™ (Boston Scientific, Natick, MA, USA) and EZ STEER™ (Biosense Webster, Inc., Diamond Bar, CA, USA) catheter handles. Here, we present a clinical report in which the Amigo™ RCS (Catheter Precision, Inc., Mount Olive, NJ, USA) was employed to map and ablate symptomatic supraventricular tachycardia. Dr. Cohen’s clinical experience with this robotic system is also reviewed.

Dose-Decreasing Effect of the First Reversed Laser Beam Collimator for C-Arm Type Angiographic Equipment

This is a study on the dose-decreasing effect of the first reversed laser beam collimator (RLBC) for C-arm type angiographic equipment. A laser beam was located at the center of each plane at an oblique angle to the angiographic equipment detector. A field of view, which could be seen with the naked eye, was made by focusing the laser beam in the direction of the X-ray source. The height of the table was fixed at 75 cm and the iron balls were located within 2 mm of the top, bottom, left, and right edges of the output image. The time needed for location fixing, fluoroscopy, and measurement of dose area product (DAP) were compared by having 30 radiologists perform location fixing by looking at the fluoroscopic image while performing location fixing (no radiation) and while the RLBC was turned on. In the next test, the time needed for location fixing, fluoroscopy, and DAP were compared when varying the location of the iron balls from 2 to 10 mm from the edges of the output image. The results showed that the time needed for location fixing, the time needed for fluoroscopy, and DAP decreased, both in the first test and the second test. This study confirmed that the use of a RLBC for C-arm type angiographic equipment decreases both the time needed to perform the procedure and the radiation dose received. It is expected that continuous advancement of RLBC technology will contribute greatly to decreasing the dose of radiation needed and improving convenience during angiography.

EFFICACY OF AN ADDITIONAL MOBILE LEADED SHIELD ON OPERATOR RADIATION DURING PERCUTANEOUS CORONARY ANGIOGRAPHY

Operator radiation protection during percutaneous coronary angiography (CA) is a growing concern in the catheterisation laboratory (cath lab). The purpose of this study was to evaluate the efficacy of an additional mobile leaded shield on operator radiation exposure during diagnostic CA. The study involved two operators from the same cath lab and patients scheduled for diagnostic coronary catheterisation over a period of 2 months. Procedures were performed with standard radiation equipment during the first month. An additional mobile lead shield was added during the second month. Radiation exposure was measured by three dosimeters positioned on the operator's left hand, on their chest under the lead apron and on lead glasses. The intra-operator results were compared. Ninety-nine per cent of the procedures were carried out by radial access. For Operators 1 and 2, the mobile shield, respectively, decreased the radiation dose to the eyes by 43 and 33 % and to the hands by 61 and 83 %. Thorax dose was less than the minimum measurable dose (<0.01 mSv) for each operator. There was no significant difference in total procedure duration, fluoroscopy time or contrast dose required between the two groups of patients. Improved operator radiation protection is an important issue in the face of increased occupational doses. Mobile leaded shield, combined with standard preventive measures, seems to be an effective additional option to reduce the radiation exposure during diagnostic CA.

Mortality in U.S. Physicians Likely to Perform Fluoroscopy-guided Interventional Procedures Compared with Psychiatrists, 1979 to 2008

Purpose To compare total and cause-specific mortality rates between physicians likely to have performed fluoroscopy-guided interventional (FGI) procedures (referred to as FGI MDs) and psychiatrists to determine if any differences are consistent with known radiation risks. Materials and Methods Mortality risks were compared in nationwide cohorts of 45 634 FGI MDs and 64 401 psychiatrists. Cause of death was ascertained from the National Death Index. Poisson regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for FGI MDs versus psychiatrists, with adjustment (via stratification) for year of birth and attained age. Results During follow-up (1979-2008), 3506 FGI MDs (86 women) and 7814 psychiatrists (507 women) died. Compared with psychiatrists, FGI MDs had lower total (men: RR, 0.80 [95% CI: 0.77, 0.83]; women: RR, 0.80 [95% CI: 0.63, 1.00]) and cancer (men: RR, 0.92 [95% CI: 0.85, 0.99]; women: RR, 0.83 [95% CI: 0.58, 1.18]) mortality. Mortality because of specific types of cancer, total and specific types of circulatory diseases, and other causes were not elevated in FGI MDs compared with psychiatrists. On the basis of small numbers, leukemia mortality was elevated among male FGI MDs who graduated from medical school before 1940 (RR, 3.86; 95% CI: 1.21, 12.3). Conclusion Overall, total deaths and deaths from specific causes were not elevated in FGI MDs compared with psychiatrists. These findings require confirmation in large cohort studies with individual doses, detailed work histories, and extended follow-up of the subjects to substantially older median age at exit. ^© RSNA, 2017 Online supplemental material is available for this article.

RADIATION PROTECTION IN AN INTERVENTIONAL LABORATORY: A COMPARATIVE STUDY OF AUSTRALIAN AND SAUDI ARABIAN HOSPITALS

This study aimed to investigate whether the use of protection devices and attitudes of interventional professionals (including radiologists, cardiologists, vascular surgeons, medical imaging technicians and nurses) towards radiation protection will differ between Saudi Arabian and Australian hospitals. Hard copies of an anonymous survey were distributed to 10 and 6 clinical departments in the Eastern province of Saudi Arabia and metropolitan hospitals in Western Australia, respectively. The overall response rate was 43 % comprising 110 Australian participants and 63 % comprising 147 Saudi participants. Analysis showed that Australian respondents differed significantly from Saudi respondents with respect to their usages of leaded glasses (p < 0.001), ceiling-suspended lead screen (p < 0.001) and lead drape suspended from the table (p < 0.001). This study indicates that the trained interventional professionals in Australia tend to adhere to benefit from having an array of tools for personal radiation protection than the corresponding group in Saudi Arabia.

THE EFFECT OF RADIATION SHIELDS ON OPERATOR EXPOSURE DURING CONGENITAL CARDIAC CATHETERISATION

Cardiac catheterisation personnel are exposed to occupational radiation and its health risks. Little data exist regarding the efficacy of radiation-protective equipment from congenital catheterisation laboratories (CLs). The authors retrospectively reviewed data in which CL operators wore a radiation dosemeter during catheterizations on patients of >20 kg. A leaded under-table skirt was present in all cases. Three additional radiation-protective devices were utilised at operator discretion: a top extension to the under-table skirt, a ceiling-mounted shield and a disposable patient drape. Case details, operator position, fluoroscopy time, incident air KERMA in the patient plane (K, mGy) and dose-area product (DAP, µGy·m²) were recorded. A total of 136 catheterizations over 8 months were included. Median operator dose (OpD) was 12 µSv (range 0-930) and indexed to K and DAP to correct for patient factors and case times. Indexed OpD decreased significantly with each additional shield used (14.8 vs. 1.3 nSv µGy^-1 m^-2 and 124 vs. 14 nSv mGy^-1 with one and four shields, respectively, p < 0.001). This trend was not significant with operator at head-of-bed. Combinations that included the ceiling shield had the lowest indexed OpD. The patient drape did not further reduce OpD when all other shields were used (1.3 vs. 2.2 nSv µGy^-1 m^-2, p = 0.5; 14 vs. 17 nSv mGy^-1, p = 0.4) and was associated with higher patient exposure indexed to weight and fluoroscopy time (4.5 vs. 3.1 µGy m² kg-min^-1, p = 0.009; and 0.51 vs. 0.38 mGy kg-min^-1, p = 0.01). Supplemental radiation barriers can decrease operator-absorbed radiation. A ceiling-mounted shield may provide greatest benefit. The authors do not recommend routine use of disposable patient drapes.

Changing Patterns in the Performance of Fluoroscopically Guided Interventional Procedures and Adherence to Radiation Safety Practices in a U.S. Cohort of Radiologic Technologists

OBJECTIVE

Information is limited on changes over time in the types of fluoroscopically guided interventional procedures performed and associated radiation safety practices used by radiologic technologists.

MATERIALS AND METHODS

Our study included 12,571 U.S. radiologic technologists who were certified for at least 2 years in 1926-1982 and who reported in a 2012-2013 survey that they ever performed or assisted with fluoroscopically guided interventional procedures. They completed a mailed questionnaire in 2013-2014 describing their detailed work practices for 21 fluoroscopically guided interventional procedures and associated radiation safety practices from the 1950s through 2009.

RESULTS

Overall, the proportion of technologists who reported working with therapeutic fluoroscopically guided interventional procedures, including percutaneous coronary interventions, increased over time, whereas the proportion of technologists who worked with diagnostic fluoroscopically guided interventional procedures, including diagnostic cardiovascular catheterization and neuroangiographic procedures, decreased. We also observed substantial increases in the median number of times per month that technologists worked with diagnostic cardiovascular catheterizations and percutaneous coronary interventions. In each time period, most technologists reported consistently (≥ 75% of work time) wearing radiation monitoring badges and lead aprons during fluoroscopically guided interventional procedures. However, fewer than 50% of the technologists reported consistent use of thyroid shields, lead glasses, and room shields during fluoroscopically guided interventional procedures, even in more recent time periods.

CONCLUSION

This study provides a detailed historical assessment of fluoroscopically guided interventional procedures performed and radiation safety practices used by radiologic technologists from the 1950s through 2009. Results can be used in conjunction with badge dose data to estimate organ radiation dose for studies of radiation-related health risks in radiologic technologists who have worked with fluoroscopically guided interventional procedures.

Risk of cancer among cardiologists who frequently perform percutaneous coronary interventions: a population-based study

BACKGROUND

Cardiologists who frequently perform percutaneous coronary interventions (PCIs) are exposed to high levels of radiation; therefore, their risk of cancer may be higher compared with other internists or cardiologists who perform fewer PCIs.

METHODS

Data were obtained from the Taiwan National Health Insurance Research Database for the 2000-2011 period. A cohort of 542 cardiologists was randomly frequency-matched according to age and sex with four other internists to form a cohort of noncardiologist controls. The incidence of cancer was measured for both cohorts, who were followed up until the end of 2011. Cox proportional hazards models were employed to analyse the risk of cancer between cardiologist and control cohorts.

RESULTS

In general, the cardiologists did not have a higher risk of cancer compared with the other internists. However, the cardiologists who worked in medical centres or regional hospitals had a higher risk of cancer than did the other internists in the same work settings. Furthermore, the cardiologists working in medical centres or regional hospitals (large hospitals) who performed >15 PCIs per year had a higher risk of cancer than did those working in district hospitals (small hospitals) or clinics who performed ≤15 PCIs per year.

CONCLUSION

Cardiologists who frequently perform PCIs have a higher risk of cancer compared with other internists or cardiologists who perform relatively fewer PCIs. Protection from radiation exposure should therefore be emphasized in coronary catheterization laboratories.

Magnetic resonance imaging compatible remote catheter navigation system with 3 degrees of freedom

PURPOSE

To facilitate MRI-guided catheterization procedures, we present an MRI-compatible remote catheter navigation system that allows remote navigation of steerable catheters with 3 degrees of freedom.

METHODS

The system consists of a user interface (master), a robot (slave), and an ultrasonic motor control servomechanism. The interventionalist applies conventional motions (axial, radial and plunger manipulations) on an input catheter in the master unit; this user input is measured and used by the servomechanism to control a compact catheter manipulating robot, such that it replicates the interventionalist's input motion on the patient catheter. The performance of the system was evaluated in terms of MRI compatibility (SNR and artifact), feasibility of remote navigation under real-time MRI guidance, and motion replication accuracy.

RESULTS

Real-time MRI experiments demonstrated that catheter was successfully navigated remotely to desired target references in all 3 degrees of freedom. The system had an absolute value error of [Formula: see text]1 mm in axial catheter motion replication over 30 mm of travel and [Formula: see text] for radial catheter motion replication over [Formula: see text]. The worst case SNR drop was observed to be [Formula: see text]3 %; the robot did not introduce any artifacts in the MR images.

CONCLUSION

An MRI-compatible compact remote catheter navigation system has been developed that allows remote navigation of steerable catheters with 3 degrees of freedom. The proposed system allows for safe and accurate remote catheter navigation, within conventional closed-bore scanners, without degrading MR image quality.

Design, development and evaluation of a compact telerobotic catheter navigation system

BACKGROUND

Remote catheter navigation systems protect interventionalists from scattered ionizing radiation. However, these systems typically require specialized catheters and extensive operator training.

METHODS

A new compact and sterilizable telerobotic system is described, which allows remote navigation of conventional tip-steerable catheters, with three degrees of freedom, using an interface that takes advantage of the interventionalist's existing dexterity skills. The performance of the system is evaluated ex vivo and in vivo for remote catheter navigation and ablation delivery.

RESULTS

The system has absolute errors of 0.1 ± 0.1 mm and 7 ± 6° over 100 mm of axial motion and 360° of catheter rotation, respectively. In vivo experiments proved the safety of the proposed telerobotic system and demonstrated the feasibility of remote navigation and delivery of ablation.

CONCLUSION

The proposed telerobotic system allows the interventionalist to use conventional steerable catheters; while maintaining a safe distance from the radiation source, he/she can remotely navigate the catheter and deliver ablation lesions. Copyright © 2015 John Wiley & Sons, Ltd.

Occupational health hazards of interventional cardiologists in the current decade: Results of the 2014 SCAI membership survey

BACKGROUND

Interventional cardiologists and staff are subject to unique physical demands that predispose them to distinct occupational health hazards not seen in other medical disciplines.

METHODS

To characterize the prevalence of these occupational health problems, The Society for Cardiovascular Angiography and Interventions (SCAI) surveyed its members by email. Inquiries included age, years of invasive practice, and diagnostic and interventional cases per year. Questions focused on orthopedic (spine, hips, knees, and ankles) and radiation-associated problems (cataracts and cancers).

RESULTS

There were 314 responses. Responders were on average busy and experienced, performing a mean of 380±249 diagnostic and 200±129 interventional cases annually. Of the responders, 6.9% of operators have had to limit their caseload because of radiation exposure and 9.3% have had a health-related period of absence. Furthermore, 153 (49.4%) operators reported at least one orthopedic injury: 24.7% cervical spine disease, 34.4% lumbar spine problems, and 19.6% hip, knee or ankle joint problems. Age was most significantly correlated with orthopedic illnesses: cervical injuries (χ2=150.7, P<0.0001); hip/knee or ankle injuries (χ2=80.9, P<0.0001); lumbar injuries (χ2=147.0, P<0.0001); and any orthopedic illness (χ2= 241.2, P<0.0001). Annual total caseload was also associated: the estimated change in the odds of orthopedic illness for each additional total caseload quintile is 1.0013 (1.0001, 1.0026). There is a small but substantial incidence of cancer.

CONCLUSIONS

These findings are consistent with, and extend the findings, of a prior 2004 SCAI survey, in documenting a substantial prevalence of orthopedic complications among active interventional cardiologists, which persists despite increased awareness.

Complex robotic-enhanced percutaneous coronary intervention

A remote-controlled, robotic system was developed to address procedural challenges and occupational hazards associated with traditional percutaneous coronary intervention (PCI). The PRECISE (Percutaneous Robotically Enhanced Coronary Intervention) Study demonstrated the safety and feasibility of the robotic system. We report four cases of complex coronary interventions demonstrating the capabilities of robotic-enhanced PCI to treat multilesion, multivessel coronary disease, saphenous venous graft disease, and an ST-elevation myocardial infarction. The robotic system offers enhanced visibility, precise measurement, accurate stent positioning, improved ergonomics, and superior operator protection from radiation.