The ethics committee of the City of Vienna approved the collection of the participants data during a live radiation training under the identifier EK 18-075-0618. All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki declaration of 1975, as revised in 2008.

The participants consisted of surgical residents, medical students, and scrub nurses who were expected to participate in real-life endovascular procedures. Before participating in the training, they received a standardized refresher on X‑ray exposure, radiation safety, and handling of the C‑arm.

Central to our simulation was a negative cast of a 3D print of a patient’s aorta made from silicone. When placed under a Ziehm Vision RFD (Ziehm Imaging GmbH, Nuremberg, Germany) and primed with silicone spray and water, the image rendered resembles an overlay after angiography (Figs. 1 and 2).

We filmed and cut a video depicting cannulation of the left renal artery. The goal of the training was to cannulate the left renal artery using a soft wire and an appropriate catheter and to switch to a semi-stiff wire. A standardized layout of different wires and catheters was available to the trainees.

The trainees received the training video before the training date and were asked to study it (Video 1). A standardized presentation using the video was given to each group of trainees directly before the training session. The trainees were randomized to a control and an intervention group. Both groups participated in an inaugural training session. Their performance was rated on a standardized five-point scale in the style of the Objective Structured Assessment of Technical Skills (OSATS) global rating scale ([3]; Fig. 3). Because multiple tasks, e.g., exact handling of the wires and catheters, fluoroscopy, collimation, and C‑arm setting had to be observed simultaneously, we filmed the trainees’ performance from multiple angles to allow the observer to review the performance of the trainees after each session. Additionally, we recorded the total time of each session and the radiation time and dose. After the first training session, the intervention group had the opportunity to train using the simulator for another 30 min and to review the instructional video. Afterwards, they were asked to perform another training session, which was observed and rated.

Trainees were responsible for operating the C‑arm and choosing the collimation and settings. The key switch was kept in an X‑ray off position until appropriate settings were chosen by the trainees to ensure minimal radiation exposure.

Descriptive statistics of the collected data include means, medians, and standard deviations (SD). Wilcoxon signed-rank and rank sum tests were used to compare group means. A p-value < 0.05 was considered statistically significant. Statistical analyses were performed in R using RStudio (Posit PBC, Boston, MA, USA).