The European Society for Vascular Surgery (ESVS) has released clinical practice guidelines on radiation safety, which the writing committee notes are the first guidelines on the topic to be published under the auspices of a vascular surgical society. The guidelines were published online ahead of print in the European Journal of Vascular and Endovascular Surgery (EJVES) and presented for the first time at this year’s ESVS annual meeting (ESVS 2022; 20–23 September, Rome, Italy).
Bijan Modarai (Guy’s and St Thomas’ NHS Foundation Trust and King’s College, London, UK) and Stéphan Haulon (Hôpital Marie Lannelongue, GHPSJ, Paris, France) co-chaired the guideline writing committee that included 13 members in total which, as well as vascular surgeons and interventional radiologists, included a radiation protection scientist and a medical physicist.
In EJVES, the authors outline the aim of the guidelines as being “to inform the reader about radiation physics and radiation dosimetry, raising awareness of the risks of ionising radiation, and describing the methods available to protect against radiation exposure”.
The need for guidelines on radiation safety has grown in line with the rise of endovascular procedures over the last two decades, Modarai, Haulon et al state in the introductory chapter. They note that the risks of radiation exposure, however, are “not universally recognised” due to a “poor understanding of key concepts and paucity of educational material directly relevant to vascular surgery”.
The authors cover measuring radiation exposure and the associated risks of exposure, legislation regarding exposure limits for radiation-exposed workers, and radiation safety practices and protection equipment in the operating room, among other topics.
At ESVS 2022, Modarai stated that the “pioneering” new document, as described by writing committee member Anders Wanhainen (Uppsala University, Uppsala, Sweden), is long-awaited—the culmination of two years of work. He expressed that while the guidelines will help to raise awareness amongst stakeholders and set the standard for individuals and institutions, these also underline the fact that this is an evolving area of practice and highlight areas where more research is needed.
The future is radiation free
In a chapter on future technologies and gaps in evidence, Modarai et al underline the fact that several recommendations are supported by level C evidence and are relying on expert opinion of the committee, which they say “highlights the need for the vascular community and allied disciplines to instigate studies that will strengthen the evidence base for radiation protection matters”. New technologies—including 3D navigation, robotic tracking, and artificial intelligence—that require a reduced need for X-ray “should be embraced and evaluated carefully,” for example.
At ESVS 2022, Joost van Herwaarden (Utrecht University Medical Center, Utrecht, The Netherlands), who disclosed a research collaboration with Philips, spoke on the benefits and drawbacks of some of these technologies, speaking first on robotic navigation. He highlighted its ability to reduce radiation exposure for the operator and increase accuracy of catheter positioning, while acknowledging that the technology still carries the limitations associated with fluoroscopy use, due to its requirement for navigation.
Another technology is intravascular ultrasound (IVUS). “You get circular information about the vessel wall, the lumen, and also about aortic side branches, as well as improved arterial wall and stenosis characterisation, and improved sizing for your percutaneous transluminal angioplasty,” he said, noting however that visualisation length is limited to the ultrasound transducer, which is “why you still need fluoroscopy for navigation of your endovascular devices” with the use of IVUS.
According to Van Herwaarden, electromagnetic tracking addresses the limiting factors of greyscale images, offering instead brightly coloured images, as well as 3D navigation of devices, unlimited viewing angles, and no radiation, with the limited numbers of wires and catheters being a drawback.
Fiber Optic RealShape (FORS) technology from Philips also shows potential in this space, offering the benefits of 3D navigation, unlimited viewing angles, and the radiation-reducing benefits associated with the use of light instead of fluoroscopy, Van Herwaarden highlighted. He noted that one drawback is the fact there are only a limited number of devices available.
Finally, the presenter gave an overview of the pros and cons of image fusion. He stated that there is one system in this space—the Cydar Medical system—that offers automated registration. This technology compares the anatomy visible on live fluoroscopy with anatomy of a preoperative computed tomography angiography (CTA) and automatically produces 3D overlay, he explained. According to the presenter, this technology offers “a significant reduction of contrast agent and also reduction of procedure time,” despite having a somewhat “complex setup”. Image fusion is “widely available” and, in the presenter’s opinion, “should be used in all complex procedures”.
Van Herwaarden summarised that these technologies show radiation-reducing potential, the small number of available publications suggest that these techniques are “still minimally applied”. According to the presenter, the future of these technologies lies in their combined use. For example, he said that, while electromagnetic tracking and FORS are “still under development,” they do offer “an even greater promise for simplifying complex procedures and realising dose reduction for patients and for staff,” when used in combination with IVUS or a robotic navigation system.
“Performing endovascular interventions without any form of radiation is certainly the future,” he concluded.
Education and training are paramount
Another chapter of the guidelines is dedicated to education and training. Speaking to Vascular News on the topic, Isabelle Van Herzeele (Ghent University Hospital, Ghent, Belgium) highlighted the necessity of starting early with education and training in radiation safety. “Ideally we should start training about radiation protection in medical school or in nursing school, so that everybody is aware of the dangers and knows the theory about justification (do benefits outweigh the risks), optimisation (obtain image of sufficient quality to guide treatment while respecting the ALARA principle in real life) and dose limits (be aware of possible side effects)”. She noted also that several technologies exist to remove radiation as a factor at the practical training stage. “Nowadays, you should have the opportunity to train in a radiation-free environment, so using simulation to learn steps, basic endovascular skills, and how to manoeuvre your C-arm without being exposed,” she said.
Furthermore, Van Herzeele underlined the benefits of continued training in radiation safety, especially regarding the changing technological landscape outlined by Van Herwaarden. “Techniques and the materials that we use are evolving, and whenever big changes are being made in your radiation safety environment, additional training should take place, with the overarching goal of ensuring we can treat our patients safely and protect everybody within the team.”
Van Herzeele also expressed her hope that these new guidelines will not only provide awareness on the risks of radiation, as well as practical steps for reducing exposure, but also provide vascular team members with some “backup” if ever faced with addressing a manager about the need to improve radiation safety protection within the endovascular operating room.