Occupational hazards of interventional cardiology

A Human-Scale Clinically Ready Electromagnetic Navigation System for Magnetically Responsive Biomaterials and Medical Devices

Magnetic navigation systems are used to precisely manipulate magnetically responsive materials enabling the realization of new minimally invasive procedures using magnetic medical devices. Their widespread applicability has been constrained by high infrastructure demands and costs. The study reports on a portable electromagnetic navigation system, the Navion, which is capable of generating a large magnetic field over a large workspace. The system is easy to install in hospital operating rooms and transportable through health care facilities, aiding in the widespread adoption of magnetically responsive medical devices. First, the design and implementation approach for the system are introduced and its performance is characterized. Next, in vitro navigation of different microrobot structures is demonstrated using magnetic field gradients and rotating magnetic fields. Spherical permanent magnets, electroplated cylindrical microrobots, microparticle swarms, and magnetic composite bacteria-inspired helical structures are investigated. The navigation of magnetic catheters is also demonstrated in two challenging endovascular tasks: 1) an angiography procedure and 2) deep navigation within the circle of Willis. Catheter navigation is demonstrated in a porcine model in vivo to perform an angiography under magnetic guidance.

Safety and feasibility study of a novel robotic system in an in vivo porcine vascular model

PURPOSE

The goal of this preclinical study is to assess the functionality, technical feasibility, and safety of a new vascular robotic LIBERTYR 3 System, in the microcatheterization of vascular targets using a range of guidewires and microcatheters.

MATERIAL AND METHODS

An anesthetized pig served as an arterial model for the robotic device (LIBERTYR3; Microbot Medical Ltd, Yoqneam, IL). The primary efficacy endpoint was the evaluation of its capability to selectively catheterize predetermined distal arterial branches in the liver, kidneys, and mesenteric arteries (technical success), under fluoroscopy guidance. The primary safety endpoint was the occurrence of angiographic acute catheterization-related complications (dissection, thrombosis, embolism, perforation). The catheterizations were conducted by two interventional radiologists that present different work experience in endovascular procedures (18 and 2 years respectively), using a variety of microcatheters and wires. Various procedural parameters such as functionality, practicality, ease of use, and time required for selective catheterization, were evaluated, and recorded.

RESULTS

All pre-determined arteries were successfully selectively catheterized (100% technical success), by both operators. No angiographic acute complications occurred. The microcatheters and wires were manipulated using the remote portable console in an effortless manner that maintained a high level of accuracy. Mean time for selective catheterization was 131 ± 82 s. The robot's conversion function to manual operation was successfully demonstrated.

CONCLUSION

Robotic navigation and catheterization of selected target arteries were accomplished without observable vascular damage, suggesting that the LIBERTYR 3 robotic system is a reliable and safe tool for robotic-assisted endovascular navigation. Further experimental studies are required to evaluate safety and efficacy prior to introduction into clinical practice.

What happened when medical staff in Beijing, China wore over-apron dosemeters?

The wearing method of personal dosemeters for medical staff changed from under to outside the operator's protective apron in April 2020. We measured the radiation dose Hp(10) for medical staff in Beijing from September 2020 to October 2021. The study population consisted of 3291 medical staff. All participants were divided into three groups. After excluding unusually low doses, the collected data higher than the detection limit involved 811 (7.8%) of 10 395 readings from 479 (14.6%) of 3291 staff. The mean equivalent dose was 1.4 mSv/3 months, with an SD of 2.3 mSv. The calculated average annual effective doses of radiation workers in the three groups after the interventional procedures from September 2020 to October 2021 ranged from 0.47 to 0.63 mSv/year, with median values of 0.32, 0.23 and 0.26 mSv/year, respectively.

Evaluation of the R-One robotic system for percutaneous coronary intervention: the R-EVOLUTION study

BACKGROUND

R-One is a robotic percutaneous coronary intervention (PCI) system (CE mark 2019) designed to reduce operator radiation exposure, improve ergonomics, and accurately navigate, position, and deliver guidewires/devices during PCI.

AIMS

We aimed to evaluate the safety and efficacy of the R-One system for PCI.

METHODS

The European multicentre prospective R-EVOLUTION study included patients with a de novo coronary artery stenosis (length <38 mm, reference diameter 2.5-4.0 mm) undergoing stent implantation. Patients with recent ST-segment elevation myocardial infarction, ostial or left main lesion, bifurcation, severe tortuosity, or calcification were excluded. Clinical success was defined as the absence of major intraprocedural complications. Technical success was defined as the successful advancement and retraction of all PCI devices (guidewires/balloon/stents) without total manual conversion. Radiation exposure to patients, to a simulated manual operator, and to robotic PCI operators was measured.

RESULTS

Sixty-two consecutive patients (B2/C lesions: 25.0% [16/64]) underwent robotic PCI. Radial access was used in 96.8% (60/62) of procedures. The mean robotic procedure duration was 19.9±9.6 min and the mean fluoroscopy time was 10.3±5.4 min. Clinical success was 100% with no complications at 30 days. Technical success was 95.2% (59/62). Total manual conversion was required in 4.8% (3/62) cases, with 1 case directly related to the robotic system. Operator radiation exposure was reduced by 84.5% under and 77.1% on top of the lead apron, compared to doses received on the patient table.

CONCLUSIONS

This study suggests that robotic PCI using R-One is safe and effective with markedly lower radiation exposure to the operator. Further studies are needed to evaluate R-One in larger patient populations with more complex lesions. (ClinicalTrials.gov: NCT04163393).

X-Ray Protective Aprons Re-Evaluated

BACKGROUND

The evaluation of the protective effect of X-ray protective clothing requires new criteria. The current concept assumes more or less uniform covering of the torso with protective material. The frequently worn heavy wrap-around aprons can weigh 7 to 8 kg. As relevant studies show, orthopedic damage can result from long-term activity. It should therefore be investigated whether the apron weight can be reduced by optimizing the material distribution. For a radiobiological evaluation of the protective effect, the "effective dose" should be used.

METHODS

Numerous laboratory measurements were performed with an Alderson Rando phantom as well as dose measurements on clinical personnel. The measurements were supplemented by Monte Carlo simulation of an interventional workplace in which a female ICRP reference phantom was used for the operator. The measured back doses on the Alderson phantom as well as the measured back doses at interventional workplaces were based on the personal equivalent dose Hp(10). Monte Carlo simulations were used to introduce protection factors for the protective clothing based on the "effective dose" introduced in radiation protection.

RESULTS

Back doses in clinical radiology personnel are largely negligible. Therefore, back protection can be much lower than currently used or can even be eliminated. The Monte Carlo simulations show that the protective effect of protective aprons worn on the body is higher than when the flat protective material is radiated through (3 D effect). About 80 % of the effective dose is attributed to the body region from the gonads to the chest. By additional shielding of this area, the effective dose can be lowered or, optionally, aprons with less weight can be produced. Attention must also be paid to the "radiation leaks" (upper arms, neck, skull), which can reduce the whole-body protective effect.

CONCLUSION

In the future, the evaluation of the protective effect of X-ray protective clothing should be based on the effective dose. For this purpose, effective dose-based protection factors could be introduced, while the lead equivalent should be used for measurement purposes only. If the results are implemented, protective aprons with approx. 40 % less weight can be produced with a comparable protective effect.

KEY POINTS

· The protective effect of X-ray protective clothing should be described by protection factors based on effective dose.. · The lead equivalent should only be used for measurement purposes.. · More than 80 % of the effective dose is attributed to the body region from the gonads to the chest.. · A reinforcing layer in this area increases the protective effect considerably.. · With optimized material distribution, protective aprons could be up to 40 % lighter..

CITATION FORMAT

· Eder H. X-Ray Protective Aprons Re-Evaluated. Fortschr Röntgenstr 2023; 195: 234 - 243.

Ionizing radiation exposure during adulthood and risk of developing central nervous system tumors: systematic review and meta-analysis

Many studies on ionizing radiation (IR) exposure during childhood have shown deleterious effects on the central nervous system (CNS), however results regarding adult exposure are inconsistent, and no systematic reviews have been performed. The objectives are to synthesize the findings and draw evidence-based conclusions from epidemiological studies on the risk of benign and malignant brain and CNS tumors in humans exposed to low-to-moderate doses (< 0.5 Gy) of IR during adulthood/young adulthood. A systematic literature search of four electronic databases, supplemented by a hand search, was performed to retrieve relevant epidemiological studies published from 2000 to 2022. Pooled excess relative risk (ERR_pooled) was estimated using a random effect model. Eighteen publications were included in the systematic review and twelve out of them were included in a meta-analysis. The following IR sources were considered: atomic bombs, occupational, and environmental exposures. No significant dose-risk association was found for brain/CNS tumors (ERR_pooled at 100 mGy = − 0.01; 95% CI: − 0.05, 0.04). Our systematic review and meta-analysis did not show any association between exposure to low-to-moderate doses of IR and risk of CNS tumors. Further studies with histological information and precise dose assessment are needed.

Effect of Different Anthropometric Body Indexes on Radiation Exposure in Patients Undergoing Cardiac Catheterisation and Percutaneous Coronary Intervention

Background: Patient factors, such as sex and body mass index (BMI), are known to influence patient radiation exposure. Body surface area (BSA) and its association with patient radiation exposure has not been well studied. Methods and Results: We analysed height, weight, BMI and BSA in consecutive patients undergoing cardiac catheterisation and percutaneous coronary intervention (PCI) at a high-volume Australian centre between September 2016 and April 2020 to assess their association with dose–area product (DAP, Gycm²). The mean age of the cohort was 64.5 ± 12.3 years with males comprising 68.8% (n = 8100, 5124 diagnostic cardiac catheterisation cases and 2976 PCI cases). Median male BMI was 28.4 kg/m² [IQR 25.2–32.1] versus 28.8 kg/m² [24.7–33.7] for females, p = 0.01. Males had higher BSA (2.0 ± 0.2 m²) than females (1.78 ± 0.2 m²), p = 0.001. Each 0.4 m² increase in BSA conferred a 1.32x fold change in DAP (95% CI 1.29–1.36, p ≤ 0.001). Each 5 kg/m² increase in BMI was linked to a 1.13x DAP fold change (1.12–1.14, p ≤ 0.001). Male sex conferred a 1.23x DAP fold change (1.20–1.26, p ≤ 0.001). Multivariable modelling with BMI or BSA explained 14% of DAP variance (R² 0.67 vs. 0.53 for both, p ≤ 0.001). Conclusions: BSA is an important anthropometric measure between the sexes and a key predictor of radiation dose and radiation exposure beyond sex, BMI, and weight.

[Electromagnetic interference in 3D-mapping procedures]

Catheter-based ablation is nowadays a safe and widespread procedure for the treatment of cardiac arrhythmia. This requires exact anatomical knowledge both before and during the examination and is an important prerequisite for targeted treatment. At the beginning of the era of interventional catheter-based treatment, fluoroscopy was the only and usual means of visualization, whereas in the middle of the 1990s continuous 3D-mapping systems were developed for the non-fluoroscopic examination of patients. The correct use of these 3‑D systems, which non-fluoroscopically visualize the catheter and mostly identify mechanisms of arrhythmia in great detail, nowadays makes an important contribution to successful interventional catheter treatment of arrhythmia; however, it is not uncommon for patients with ventricular arrhythmia to also carry implanted electronic devices, such as pacemakers, defibrillators or less frequently left ventricular hemodynamic support systems. All implantable devices lead to electromagnetic interferences, which can complicate the diagnostics and treatment during electrophysiological examinations and ablation. This article addresses the adversities and experiences associated with magnet-based 3D systems and implantable electromagnetically active cardiac devices.

Pilot Animal Study on Robotic-Assisted Endovascular Visceral Interventions

Purpose

To evaluate technical feasibility and safety of common endovascular visceral interventions using a vascular robotic platform through preclinical study.

Material and Methods

The CorPath GRX Robotic System (Corindus Inc, Waltham, Massachusetts) was tested in an anesthetized pig for its ability to navigate various commercially available devices in the abdominal vasculature and to perform routine endovascular visceral procedures. After manually placing a guiding catheter in the celiac trunk, several visceral branches were probed with microcatheters and -wires under robotic assistance, and embolization with liquids (lipiodol), detachable coils and plugs were performed. Furthermore, the origin of the celiac trunk was stented before accessing the left hypogastric artery for pelvic embolization.

Results

All procedures were performed with technical success and without any complications. Navigating the catheters and wires via the steering console proved intuitive. Coil, plug and stent deployment were exclusively controlled by remote with remarkable precision and stability.

Conclusion

Robotic-assisted visceral embolization and stenting as well as pelvic embolization using the CorPath GRX System is feasible and safe. Application of the platform in the abdominal vasculature is demonstrated for the first time. Considering the precision and the potential for reducing the operator’s radiation exposure, further research in this area is highly encouraged to enable translation into clinical practice.

Robot-assisted techniques in vascular and endovascular surgery

For thousands of years, robots have inspired the imagination of humans, but it was only about 35 years ago that a robot was used for the first time in medicine. Since then, robot-assisted procedures have become increasingly popular in urology, general surgical specialties, and gynecology. Robot-assisted vascular surgery was first introduced in 2002 and was thought to overcome the limitations of laparoscopy. However, it did not gain widespread popularity, and its usage is still limited to a few centers worldwide. Robot-assisted endovascular procedures, on the other hand, while still in its infancy, have become a promising alternative to existing techniques. The improvements of the robotic systems promote better surgical performance and reduce occupational hazards for vascular and endovascular surgeons. A comprehensive review of literature was performed using the search terms “robotic,” “robot assisted,” “vascular surgery,” and “aortic” for surgical procedures or “robotic,” “robot assisted,” and “endovascular” for endovascular procedures. Full text articles that were published between January 1990 and March 2021 were included. This review summarizes the development of the techniques for robot-assisted vascular and endovascular surgery in recent years, its outcomes, advantages, disadvantages, and perspectives.

Safety and effectiveness of introducing a robotic-assisted percutaneous coronary intervention program in a tertiary center: a prospective study

BACKGROUND

Robotic-assisted percutaneous coronary intervention (PCI) is a novel technology that permits remote operation of interventional devices. However, little is known about the safety and effectiveness of introducing a robotic PCI program in a hospital already experienced in traditional coronary angioplasty.

METHODS

Prospective single-arm survey to assess the safety and effectiveness of robotic-assisted PCI in comparison to pre-defined performance goals. The study cohort comprised all consecutive cases treated with robotic PCI since its introduction. The safety primary endpoint was a composite of (I) overall death or (II) non-fatal adverse events related to target vessel complications (stent thrombosis, myocardial infarction, vessel perforation or cardiac tamponade, or repeat invasive treatment) during the index hospitalization. The efficacy primary endpoint was robotic-assisted procedural success, a composite of (I) successful dilatation of the target lesion and (II) successful robotic assistance, defined as absent non-planned manual conversion.

RESULTS

A total of 83 patients and 112 lesions were prospectively enrolled. The rate of angiographic success was 99.1%. From these, 97 lesions (86.6%) were treated with only robotic PCI or with hybrid according to the pre-interventional plan. The rates of efficacy and safety primary endpoints were 85.7% and 2.4% respectively (P<0.01 for non-inferior to the pre-defined performance threshold).

CONCLUSIONS

Introduction of robotic-assisted PCI in a tertiary center was associated with safe and effective results, comparable to pre-defined goals of optimal performance.

The use of digital magnification to reduce radiation dose in the cardiac catheter laboratory

OBJECTIVES

To audit whether using magnification of images by use of a large viewing screen using digital matrix magnification which enlarges the image by 33% without using the X-ray machine zoom magnification protocols on a Siemens Artis Zee X-ray machine in a cardiac catheter laboratory results in a reduction of kerma-area product (KAP) for both diagnostic and interventional procedures. This reduction was predicted in an in vitro study in our laboratory, which has previously shown a 20.4% reduction in KAP.

METHODS

A retrospective analysis was conducted of the radiation exposure to compare the measured KAP recorded during the period when conventional magnification with automatic brightness and dose control was used on a Siemens Artis Zee X-ray machine with a flat panel detector and when magnification settings were avoided by using a large screen to enlarge and project a non-magnified image by digital magnification. The analysis was carried out for patients having a diagnostic coronary angiogram and those having an interventional coronary procedure.

RESULTS

For diagnostic coronary angiograms the median KAP per procedure in the period using conventional magnification was 2124.5 µGy.m² compared to 1401 µGy.m² when image matrix magnification was used, a 34% reduction (p < 0.0001). For interventional coronary procedures, the median KAP per procedure in the period using conventional magnification was 3791 µGy.m² compared to 2568.5 µGy.m² when image matrix magnification was used, a 32% reduction (p < 0.0001).

CONCLUSION

Avoiding using conventional magnification in the cardiac catheter laboratory and using a large screen to magnify images was associated with a statistically significant greater than 30% reduction in KAP.

ADVANCES IN KNOWLEDGE

This paper is the proof in clinical practice of a theoretical conclusion that radiation dose (KAP) is reduced by use of Image matrix magnification using a large viewing screen without the need to use X-ray tube magnification without significant loss of image resolution in interventional cardiology. The same approach will be useful in interventional radiology.

Use of effective dose to assess x-ray protective clothing

This review article provides an overview on the results of studies conducted by the authors to improve the current personal protection concept in the clinical application of x-rays. With the aid of personal dose equivalent measurements during radiologically guided clinical interventions, laboratory tests using the Alderson-Rando phantom as well as Monte Carlo simulations various x-ray application scenarios were investigated. The organ doses and the effective doses of staff persons standing near the patient were determined. The 3D-attenuation properties of protective clothing under the scattered radiation emitted by the patient play a special role here. With regard to the minimisation of the quantity 'effective dose' the protection of the lower body from the gonads to the chest is of particular importance, since 80% of the effective dose is contributed by this region of the body. In contrast, protection of the back plays a subordinate role. Protective aprons optimised in terms of effective dose can be significantly lighter than conventional aprons, providing equal protection. The assessment of the attenuation properties of protective clothing should be based on the risk-related dose quantity, effective dose, rather than lead equivalent. In the future, the evaluation of radiation protective clothing could be based on the calculation of the effective dose assuming standardised irradiation conditions.

OCCUPATIONAL EXPOSURE IN RADIATION APPLICATIONS IN INDIA: TRENDS AND DISTRIBUTION ANALYSIS

Occupational exposure data in radiation applications provide a good insight on the radiation risks to workers from occupational hazards, the safe practices adopted and in deriving methods to prevent possible radiation exposures. The analysis of occupational exposure may be used to provide regulatory guidance and more focused attention to improve the safety systems, thus improving the personnel and environment safety. In this study, occupational exposure from radiation applications during 2004-18 amounting to a total number of 1951 486 occupational dose data are collected and analysed using the statistical software package, SPSS. As recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation, four critical parameters viz., annual collective effective dose, average annual effective dose, individual dose distribution ratio and the annual collective dose distribution ratio for each practice are estimated. Using the trend observed for these parameters, it is predicted that occupational exposure in diagnostic radiology in the year 2023 would increase by 80% in total number of monitored with 76% increase in average collective dose and no significant change in average annual effective dose. In the same manner, nuclear medicine would see 28% of increase in radiation workers with the increase of 24% in collective dose with no significant change in average annual effective dose. Further, the reasons and area of regulatory focus for the different practices are discussed.

Design and Performance Evaluation of a Novel Vascular Robotic System for Complex Percutaneous Coronary Interventions

The robotic-assisted percutaneous coronary intervention is an emerging technology with great potential to solve the shortcomings of existing treatments. However, the current robotic systems can not manipulate two guidewires or ballons/stents simultaneously for coronary bifurcation lesions. This paper presents VasCure, a novel bio-inspired vascular robotic system, to deliver two guidewires and stents into the main branch and side branch of bifurcation lesions in sequence. The system is designed in master-slave architecture to reduce occupational hazards of radiation exposure and orthopedic injury to interventional surgeons. The slave delivery device has one active roller and two passive rollers to manipulate two interventional devices. The performance of the VasCure was verified by in vitro and in vivo animal experiments. In vitro results showed the robotic system has good accuracy to deliver guidewires and the maximum error is 0.38mm. In an animal experiment, the interventional surgeon delivered two guidewires and balloons to the left circumflex branch and the left anterior descending branch of the pig, which confirmed the feasibility of the vascular robotic system.

First in Man Pilot Feasibility Study in Extracranial Carotid Robotic-Assisted Endovascular Intervention

BACKGROUND

Robotic-assistance in endovascular intervention represents a nascent yet promising innovation.

OBJECTIVE

To present the first human experience utilizing robotic-assisted angiography in the extracranial carotid circulation.

METHODS

Between March 2019 and September 2019, patients with extracranial carotid circulation pathology presenting to Houston Methodist Hospital were enrolled.

RESULTS

A total of 6 patients met inclusion criteria: 5 underwent diagnostic angiography only with robotic-assisted catheter manipulation, while 1 underwent both diagnostic followed by delayed therapeutic intervention. Mean age was 51 +/- 17.5 yr. Mean anesthesia time was 158.7 +/- 37.9 min, mean fluoroscopic time was 22.0 +/- 7.3 min, and mean radiation dose was 815.0 +/- 517.0 mGy. There were no technical complications and no clinical deficits postprocedure. None of the cases required conversion to manual neurovascular intervention (NVI).

CONCLUSION

Incorporating robotic technology in NVI can enhance procedural technique and diminish occupational hazards. Its application in the coronary and peripheral vascular settings has established safety and efficacy, but in the neurovascular setting, this has yet to be demonstrated. This study presents the first in human feasibility experience of robotic-assisted NVI in the extracranial carotid circulation.

Interventional radiologists have a higher rate of chromosomal damage due to occupational radiation exposure: a dicentric chromosome assay

OBJECTIVES

There are growing concerns regarding radiation exposure in medical workers who perform interventional fluoroscopy procedures. Owing to the nature of certain interventional procedures, workers may be subjected to partial-body radiation exposure that is high enough to cause local damage. We aimed to investigate the level of radiation exposure in interventional radiologists in South Korea by performing cytogenetic biodosimetry, particularly focusing on partial-body exposure.

METHODS

Interventional radiologists (n = 52) completed a questionnaire, providing information about their work history and practices. Blood samples were collected and processed for a dicentric chromosome assay. We determined Papworth's U-value to assess the conformity of dicentrics with the Poisson distribution to estimate the partial-body exposures of the radiologists.

RESULTS

Radiologists had a higher number of dicentrics than the normal population and industrial radiographers. Indeed, subjects with a U-value of > 1.96, an indicator of heterogeneous exposure, were observed more frequently; 4.67 ± 0.81% of their body was irradiated at an average dose of 4.64 ± 0.67 Gy. Logistic regression analysis revealed that the total duration of all interventional procedures per week was associated with partial-body exposure levels.

CONCLUSIONS

Our findings suggest that interventional radiologists had greater chromosomal damages than those in other occupational groups, and their partial-body exposure levels might be high enough to cause local damage. Use of special dosimeters to monitor partial-body exposure, as well as restricting the time and frequency of interventional procedures, could help reduce occupational radiation exposure.

KEY POINTS

• Interventional radiologists had a higher number of dicentrics than the normal population and industrial radiographers. • The level of partial-body exposure of interventional radiologists might be high enough to cause occupational local damage such as a skin cancer in fingers. • Restricting the duration and frequency of interventional procedures might be helpful in reducing occupational radiation exposure.

A Review of Robotic Interventional Neuroradiology

Robotic interventional neuroradiology is an emerging field with the potential to enhance patient safety, reduce occupational hazards, and expand systems of care. Endovascular robots allow the operator to precisely control guidewires and catheters from a lead-shielded cockpit located several feet (or potentially hundreds of miles) from the patient. This has opened up the possibility of expanding telestroke networks to patients without access to life-saving procedures such as stroke thrombectomy and cerebral aneurysm occlusion by highly-experienced physicians. The prototype machines, first developed in the early 2000s, have evolved into machines capable of a broad range of techniques, while incorporating newly automated maneuvers and safety algorithms. In recent years, preliminary clinical research has been published demonstrating the safety and feasibility of the technology in cerebral angiography and intracranial intervention. The next step is to conduct larger, multisite, prospective studies to assess generalizability and, ultimately, improve patient outcomes in neurovascular disease.

Microbial Contamination Risk and Disinfection of Radiation Protective Garments

ABSTRACT

Healthcare-associated infections are a major public health concern for both patients and medical personnel. This has taken on greater urgency during the current COVID-19 pandemic. Radiation Personal Protective Equipment (RPPE) may contribute to risks of microbial contamination. This possibility was tested in 61 personal or shared-use lead aprons and thyroid collars at Columbia Presbyterian Irving Medical Center. Fifty percent tested positive for either bacterial or fungal contamination, mostly around the neckline of lead vests and thyroid collars. Repeated testing of garments some weeks to months later confirmed continued presence of microbial contamination. The possibility that hospital-approved disinfection agents could degrade the radio-protective features of these garments was also examined. Samples of identical construction to garments in regular use were subjected to either daily or weekly wipes with hypochlorite or alcohol-based hospital-approved cleaning agents for 6 mo. A third group of samples was maintained in contact with the cleaning agents for 6 mo. All samples were fluoroscoped four times during the study. None demonstrated any degradation in radioprotection. All samples were photographed monthly. Physical degradation of the outer plastic covering by concentrated hypochlorite and limited mechanical damage around stitched seams of the samples cleaned daily with alcohol was noted. Based on the high prevalence of microbial contamination, regular cleaning and disinfection protocols should be implemented. Regular cleaning with medical-facility-approved cleaning and disinfecting agents is likely to be effective at reducing the microbial load and unlikely to result in significant reduction in radioprotective properties of these garments.

Iterative Improvement and Marginal Gains in Coronary Revascularisation: Is Robot-assisted Percutaneous Coronary Intervention the New Hope?

Percutaneous coronary intervention (PCI) has undergone a rapid and adaptive evolution since its introduction into clinical practice more than 40 years ago. It is the most common mode of coronary revascularisation in use, with the scope, breadth and constellation of disease being treated increasing markedly over time. This has principally been driven by improvements in technology, engineering and training in the field, which has facilitated more complex PCI procedures to be undertaken safely. Robot-assisted PCI represents the next paradigm shift in contemporary PCI practice. It has the ability to enhance procedural accuracy for the patient while improving radiation safety and ergonomics for the operator. This state-of-the-art review outlines the current position and future potential of robot-assisted PCI.

Zero-fluoroscopy catheter ablation for atrial fibrillation: a transitional period experience

BACKGROUND

Radiofrequency catheter ablation for atrial fibrillation (AF) without using fluoroscopy has been getting popular. In this study, we reported the transition period experience of the zero-fluoroscopy procedure by an experienced operator and shared our zero-fluoroscopy protocol.

METHOD

A total of consecutive 30 AF ablation cases attempted to be treated without fluoroscopy were investigated. Ten serial cases were grouped as fluoroscopy-guided period, and period 1-3 in chronological order. All zero-fluoroscopy attempted cases were assisted with an intracardiac echocardiography device with a three-dimensional electroanatomical system.

RESULTS

Complete zero-fluoroscopy procedure was achieved at the 6th case during the transitional period. During the first period, the total procedure time slightly increased in, but afterward, procedure time was continuously decreased, and it became significantly shorter in the third period than the previous fluoroscopy-guided period. Any additional use of fluoroscopy during the transitional period was mainly for transseptal puncture and diagnostic catheter placement into the coronary sinus. Pulmonary vein isolation was achieved in all patients, and there was one case of hemodynamically insignificant moderate amount pericardial effusion.

CONCLUSION

For an experienced operator, complete zero-fluoroscopy AF ablation might be achieved safely and feasibly within 5-10 cases. Fluoroscopy equipment backup might be useful during the learning period for beginners in the zero-fluoroscopy procedure.

Patient and Provider Risk in Managing ST-Elevation Myocardial Infarction During the COVID-19 Pandemic: A Decision Analysis

BACKGROUND

The optimal treatment strategy for treating ST-segment-elevation myocardial infarction (STEMI) in context of the coronavirus disease 2019 (COVID-19) pandemic is unclear given the potential risk of occupational exposure during primary percutaneous coronary intervention (PPCI). We quantified the impact of different STEMI treatment strategies on patient outcomes and provider risk in context of the COVID-19 pandemic.

METHODS

Using a decision-analytic framework, we evaluated the effect of PPCI versus the pharmaco-invasive strategy for managing STEMI on 30-day patient mortality and individual provider infection risk based on presence of cardiogenic shock, suspected coronary territory, and presence of known or presumptive COVID-19 infection.

RESULTS

For patients with low suspicion for COVID-19, PPCI had mortality benefit over the pharmaco-invasive strategy, and the risk of cardiac catheterization laboratory provider infection remained very low (<0.25%) across all subgroups. For patients with presumptive COVID-19 with cardiogenic shock, PPCI offered substantial mortality benefit to patients relative to the pharmaco-invasive strategy (7.9% absolute decrease in 30-day mortality), but also greater risk of provider infection (2.3% absolute increase in risk of provider infection). For patients with presumptive COVID-19 with nonanterior STEMI without cardiogenic shock, PPCI offered a 0.4% absolute mortality benefit over the pharmaco-invasive strategy with a 0.2% greater absolute risk of provider infection, and the tradeoff between patient and provider risk with PPCI became more apparent in sensitivity analysis with more severe COVID-19 infections.

CONCLUSIONS

Usual care with PPCI remains the appropriate treatment strategy in the majority of cases presenting with STEMI in the setting of the COVID-19 pandemic. However, utilization of a pharmaco-invasive strategy in selected patients with STEMI with presumptive COVID-19 and low likelihood of mortality from STEMI and use of preventive strategies such as preprocedural intubation in high risk patients when PPCI is the preferred strategy may be reasonable to reduce provider risk of COVID-19 infection.

Radiation protection in the cardiac catheterization laboratory

The trend towards more minimally invasive procedures in the past few decades has resulted in an exponential growth in fluoroscopy-guided catheter-based cardiology procedures. As these techniques are becoming more commonly used and developed, the adverse effects of radiation exposure to the patient, operator, and ancillary staff have been a subject of concern. Although occupational radiation dose limits are being monitored and seldom reached, exposure to chronic, low dose radiation has been shown to have harmful biological effects that are not readily apparent until years after. Given this, it is imperative that reducing radiation dose exposure in the cardiac catheterization laboratory remains a priority. Staff education and training, radiation dose monitoring, ensuring use of proper personal protective equipment, employment of shields, and various procedural techniques in minimizing radiation must always be diligently employed. Special care and consideration should be extended to pregnant women working in the cardiac catheterization laboratory. This review article presents a practical approach to radiation dose management and discusses best practice recommendations in the cardiac catheterization laboratory.

Neuroendovascular-specific engineering modifications to the CorPath GRX Robotic System

OBJECTIVE

The aim of this study was to evaluate new, neuroendovascular-specific engineering and software modifications to the CorPath GRX Robotic System for their ability to support safer and more effective cranial neurovascular interventions in a preclinical model.

METHODS

Active device fixation (ADF) control software, permitting automated manipulation of the guidewire relative to the microcatheter, and a modified drive cassette suitable for neuroendovascular instruments were the respective software and hardware modifications to the current CorPath GRX robot, which was cleared by the FDA for percutaneous coronary and peripheral vascular intervention. The authors then trialed the modified system in a live porcine model with simulated neuroendovascular pathology. Femoral access through the aortic arch to the common carotid artery was accomplished manually (without robotic assistance), and the remaining endovascular procedures were performed with robotic assistance. The system was tested for the enhanced ability to navigate and manipulate neurovascular-specific guidewires and microcatheters. The authors specifically evaluated the movement of the wire forward and backward during the advancement of the microcatheter.

RESULTS

Navigation of the rete mirabile and an induced aneurysm within the common carotid artery were successful. The active device fixation feature enabled independent advancement and retraction of the guidewire and working device relative to the microcatheter. When ADF was inactive, the mean forward motion of the guidewire was 5 mm and backward motion was 0 mm. When ADF was active, the mean forward motion of the guidewire was 0 mm and backward motion was 1.5 mm. The modifications made to the robotic cassette enabled the system to successfully manipulate the microcatheter and guidewire safely and in a manner more suited to neuroendovascular procedures than before. There were no occurrences of dissection, extravasation, or thrombosis.

CONCLUSIONS

The robotic system was originally designed to navigate and manipulate devices for cardiac and peripheral vascular intervention. The current modifications described here improved its utility for the more delicate and tortuous neurovascular environment. This will set the stage for the development of a neurovascular-specific robot.

Ophthalmic manifestations of ionising radiation among interventionalists

Background: Ionising radiation (IR) is an occupational hazard for interventionalists. Dry eye syndrome may develop. There may be damage to the corneal epithelium, causing irritation and ulceration. Radiation-induced cataracts commonly develop in the posterior sub-capsular (PSC) region of the lens and are more common in the left eye.Aim: The aim of this study was to describe the ophthalmological findings in South African interventionalists occupationally exposed to IR.Setting: This study was conducted in South Africa.Methods: A prospective cross-sectional study was conducted. Interventional radiologists (25), adult cardiologists (42) and paediatric cardiologists (31) were recruited at conferences and included in the study. Convenience sampling was used. Participants completed a survey that collected data on their demographics, their cataract risk factors and co-morbid diseases, their occupational history, their radiation safety practices and their training in occupational history. Participants’ eyes were examined using a slit lamp after dilation of the eyes. Ethics clearance was obtained and each participant gave informed consent. A descriptive analysis was done.Results: The median age of the 98 interventionalists screened was 43.5 years. They worked with radiation for a median of 7.5 years. Cataracts occurred in the left eye of 17 (17.3%) participants and in the right eye of nine (9.2%). There were five (5.1%) PSC cataracts in the left eye and one (1%) in the right eye. The vitreous was abnormal in 19.4% of participants. The tear break-up time was abnormal in 48% of participants.Conclusion: Ionising radiation is an occupational hazard posing a risk to interventionalists’ eyes. They are at increased risk of cataracts and dry eye syndrome, which can affect their occupational performance and quality of life. Education can positively influence the radiation safety practices of interventionalists that could reduce the detrimental effects of IR on their eyes.

Personal Protective Equipment Availability and Utilization Among Interventionalists

OBJECTIVE

This study explored personal protective equipment (PPE) availability and PPE utilization among interventionalists in the catheterization laboratory, which is a highly contextualized workplace.

METHODS

This is a cross-sectional study using mixed methods. Participants (108) completed a survey. A hyperlink was sent to the participants, or they were asked to complete a paper-based survey. Purposively selected participants (54) were selected for individual (30) or group (six) interviews. The interviews were conducted at conferences, or appointments were made to see the participants. Logistic regression analysis was performed. The qualitative data were analyzed thematically.

RESULTS

Lead glasses were consistently used 10.2% and never used 61.1% of the time. All forms of PPE were inconsistently used by 92.6% of participants. Women were 4.3 times more likely to report that PPE was not available. PPE compliance was related to fit and availability.

CONCLUSIONS

PPE use was inconsistent and not always available. Improving the culture of radiation protection in catheterization laboratories is essential to improve PPE compliance with the aim of protecting patients and operators. This culture of radiation protection must include all those involved including the users of PPE and the administrators and managers who are responsible for supplying sufficient, appropriate, fitting PPE for all workers requiring such protection.

Cytogenetic status of interventional radiology unit workers occupationally exposed to low-dose ionising radiation: A pilot study

Interventional radiology unit workers represent one of the occupationally most exposed populations to low-dose ionizing radiation. Since there are many uncertainties in research of doses below 100 mSv, this study attempted to evaluate DNA damage levels in chronically exposed personnel. The study group consisted of 24 subjects matched with a control population by the number of participants, age, gender ratio, active smoking status, the period of blood sampling, and residence. Based on regular dosimetry using thermoluminiscent dosimeters, our study group occupationally received a dose of 1.82 ± 3.60 mSv over the last year. The results of the cytokinesis-block micronucleus assay and the comet assay showed a higher nuclear buds frequency (4.09 ± 1.88) and tail length (15.46 ± 1.47 μm) than in the control group (2.96 ± 1.67, 14.05 ± 1.36 μm, respectively). Differences in other descriptors from both tests did not reach statistical significance. Further investigations are needed to develop algorithms for improving personal dosimetry and those that would engage larger biomonitoring study groups.

Interventionalists' perceptions on a culture of radiation protection

BACKGROUND

Occupational exposure to ionising radiation poses potential health risks to radiation workers unless adequate protection is in place. The catheterisation laboratory is a highly contextualised workplace with a distinctive organisational and workplace culture.

OBJECTIVE

This study was conducted to understand the culture of radiation protection (CRP).

METHODS

This study was a qualitative study and data were collected through 30 in-depth and 6 group interviews with 54 purposively selected South African interventionalists (interventional radiologists and cardiologists). The participants included a diversity of interventionalists who varied in sex, geographic location and years of experience with fluoroscopy. The transcribed data were analysed thematically using a deductive and inductive approach.

RESULTS

'Culture of radiation protection' emerged as a complex theme that intersected with other themes: 'knowledge and awareness of radiation', 'radiation safety practice', 'personal protective equipment (PPE) utilisation' and 'education and training'.

CONCLUSION

Establishing and sustaining a CRP provides an opportunity to mitigate the potentially detrimental health effects of occupational radiation exposure. Education and training are pivotal to establishing a CRP. The time to establish a culture of radiation in the catheterisation laboratory is now.

First experience with zero-fluoroscopic ablation for supraventricular tachycardias using a novel impedance and magnetic-field-based mapping system

AIMS

Zero- and near-zero-fluoroscopic ablation techniques reduce the harmful effects of ionizing radiation during invasive electrophysiology procedures. We aimed to test the feasibility and safety of a zero-fluoroscopic strategy using a novel integrated magnetic and impedance-based electroanatomical mapping system for radiofrequency ablation (RFA) of supraventricular tachycardias (SVTs).

METHODS

We retrospectively studied 92 consecutive patients undergoing electrophysiology studies with/without RFA for supraventricular tachycardia (SVT) performed by a single operator at a single center. The first 42 (Group 1) underwent a conventional fluoroscopic-guided approach and the second 50 (Group 2) underwent a zero-fluoroscopic approach using the Ensite Precision^™ 3-D magnetic and impedance-based mapping system (Abbott Inc).

RESULTS

Group 1 comprised 14 AV-nodal re-entrant tachycardia (AVNRT), 12 typical atrial flutter, 4 accessory pathway (AP), 2 atrial tachycardia (AT), and 9 diagnostic EP studies (EPS). Group 2 comprised 16 AVNRT, 17 atrial flutter, 6 AP, 3 AT, 2 AV-nodal ablations, and 7 EPS. A complete zero-fluoroscopic approach was achieved in 94% of Group 2 patients. All procedures were acutely successful, and no complications occurred. There was a significant reduction in fluoroscopy dose, dose area product, and time (p < 0.0001, for all), with no difference in procedure times. Ablation time for typical atrial flutter was shorter in Group 2 (p = 0.006).

CONCLUSIONS

A zero-fluoroscopic strategy for diagnosis and treatment of SVTs using this novel 3D-electroanatomical mapping system is feasible in majority of patients, is safe, reduces ionizing radiation exposure, and does not compromise procedural times, success rates, or complication rates.

The Development of Robotic Technology in Cardiac and Vascular Interventions

Robotic technology has been used in cardiovascular medicine for over a decade, and over that period its use has been expanded to interventional cardiology and percutaneous coronary and peripheral vascular interventions. The safety and feasibility of robotically assisted interventions has been demonstrated in multiple studies ranging from simple to complex coronary lesions, and in the treatment of iliofemoral and infrapopliteal disease. These studies have shown a reduction in operator exposure to harmful ionizing radiation, and the use of robotics has the intuitive benefit of alleviating the occupational hazard of operator orthopedic injuries. In addition to the interventional operator benefits, robotically assisted intervention has the potential to also be beneficial for patients by allowing more accurate lesion length measurement, stent placement, and patient radiation exposure; however, more investigation is required to elucidate these benefits fully.

Sleep deprivation in interventional cardiology: Implications for patient care and physician-health

The burden and impact of sleep deprivation on both patient care and on the health of interventional cardiologists is not well understood. Due to the nature of emergent procedures occurring in the cardiac catheterization laboratory, interventionalists are prone to suffer from acute and/or chronic sleep deprivation. Sleep deprivation has been associated with numerous adverse effects, such as impaired performance, cognitive deficits, reduced psychomotor vigilance, and workplace errors and injuries, among many others. Although sleep deprivation has been linked to more errors in trainees, there is paucity of data addressing outcomes in interventional cardiology. The purpose of this overview is to explore the possible impact of sleep deprivation on interventional cardiology in relation to patient care and physician health, and examine potential approaches to this issue.

Perceptions of radiation safety training among interventionalists in South Africa

Exposure to ionising radiation may have deterministic and stochastic health effects, which include skin changes, chromosomal aberrations, cataracts and carcinomas. Formalised training in radiation safety and protection improves knowledge on the subject and facilitates greater compliance in safety practices. This qualitative study included 54 interventionalists (adult and paediatric cardiologists, and interventional radiologists). The participants were purposively selected and interviewed to explore their perceptions about radiation safety. A thematic analysis of the transcripts was done using a deductive and inductive approach. Findings showed participating cardiologists had less knowledge about radiation safety than participating radiologists. Cardiologists reported little or no formal training on radiation safety and did not display a culture of radiation safety. There was no consensus on how the training gap should be addressed. There is a perceived need to change and enhance the radiation safety culture among interventionists, and the participants proffered some ideas. These included the need for re-curricularisation of cardiologists’ training to create awareness of radiation safety practices.

Occupational Radiation Exposure and Deaths From Malignant Intracranial Neoplasms of the Brain and CNS in U.S. Radiologic Technologists, 1983-2012

OBJECTIVE

Childhood exposure to acute, high-dose radiation has consistently been associated with risk of benign and malignant intracranial tumors of the brain and CNS, but data on risks of adulthood exposure to protracted, low-to-moderate doses of radiation are limited. In a large cohort of radiologic technologists, we quantified the association between protracted, low-to-moderate doses of radiation and malignant intracranial tumor mortality.

MATERIALS AND METHODS

The study population included 83,655 female and 26,642 male U.S. radiologic technologists who were certified for at least 2 years as of 1982. The cohort was followed from the completion date of the first or second survey (1983-1989 or 1994-1998) to the date of death, loss to follow-up, or December 31, 2012, whichever was earliest. Occupational brain doses through 1997 were based on work history, historical data, and, for most years after the mid 1970s, individual film badge measurements. Radiation-related excess relative risks (ERRs) and 95% CIs were estimated from Poisson regression models adjusted for attained age and sex.

RESULTS

Cumulative mean absorbed brain dose was 12 mGy (range, 0-290 mGy). During follow-up (median, 26.7 years), 193 technologists died of a malignant intracranial neoplasm. Based on models incorporating a 5-year lagged cumulative brain dose, cumulative brain dose was not associated with malignant intracranial tumor mortality (overall ERR per 100 mGy, 0.1; 95% CI, < -0.3 to 1.5). No effect modification was observed by sex or birth cohort.

CONCLUSION

In this nationwide cohort of radiologic technologists, cumulative occupational radiation exposure to the brain was not associated with malignant intracranial tumor mortality.

Radiation Protection for the Fluoroscopy Operator and Staff

OBJECTIVE

The purposes of this article are to review available data regarding the range of protection devices and garments with a focus on eye protection and to summarize techniques for reducing scatter radiation exposure.

CONCLUSION

Fluoroscopy operators and staff can greatly reduce their radiation exposure by wearing properly fitted protective garments, positioning protective devices to block scatter radiation, and adhering to good radiation practices. By understanding the essentials of radiation physics, protective equipment, and the features of each imaging system, operators and staff can capitalize on opportunities for radiation protection while minimizing ergonomic strain. Practicing and promoting a culture of radiation safety can help fluoroscopy operators and staff enjoy long, productive careers helping patients.

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.

ECG-gated coronary angiography enables submillisievert imaging in invasive cardiology

BACKGROUND

The median dose area products (DAP) and effective doses (ED) of patients arising from coronary angiography (CA) are considerable: According the 2013 National German Registry, they amount to 19.8 Gy × cm(2) and 4.0 mSv, respectively.

METHODS

We investigated the feasibility of prospective electrocardiogram (ECG)-gated coronary angiography (CA)-a novel technique in invasive cardiology-with respect to possible reduction in irradiation effects. Instead of universally fix-rated radiographic acquisition within 7.5-15 frames/s, one single frame/heartbeat was triggered toward the diastolic moment immediately before atrial contraction (77 % of ECG-RR interval) most likely to provide motion-free and hence optimized resolution of the coronary tree. For 200 patients (body mass index 27.8 kg/m(2), age 67.5 years, male 55 %, 68 bpm) undergoing ECG-gated CA, we measured various median (interquartile range) parameters for radiation exposure.

RESULTS

The total DAP was 0.64 (0.46-1.00), radiographic fraction was 0.30 (0.19-0.43), and fluoroscopic fraction was 0.35 (0.21-0.57) Gy × cm(2). Radiographic imaging occurred within 21.7 s (17.1-26.3), with 25 frames (20-30) over the course of 7 runs (6-8). Fluoroscopy time was 119 s (94-141). Radiographic DAP was 12.6 mGy × cm(2)/frame and 13.8 mGy × cm(2)/s. Fluoroscopic DAP was 0.8 mGy × cm(2)/pulse and 3.1 mGy × cm(2)/s. Patient reference point air kerma was 17.0 mGy (11.1-28.1) and contrast volume was 70 ml (60-85).

CONCLUSION

In conclusion, invasive ECG-gated coronary imaging is feasible in clinical routine and enables patient EDs of approx. 3 % of typical values in invasive cardiology: 0.13 mSv (0.09-0.20).