All procedures were performed using CO
2insufflation with the patient in prone or left lateral decubitus position under conscious sedation controlled by an anesthesiologist and a nurse. The study procedures were performed using a floor-mounted Siemens Artis zee multi-purpose (MP) fluoroscopy system (Siemens Healthcare, Erlangen, Germany) or a mobile Siemens Cios Alpha c-arm device (Siemens Healthcare, Erlangen, Germany). Fixed, mobile, and ceiling-mounted radiation shields and personal protective equipment, such as protective aprons, thyroid shields, and leaded eyewear were used during all the procedures. A more detailed description of the imaging protocols and radiation protection tools implemented is provided as supplementary material.
Other data collected for each procedure included patient characteristics (age, height, weight, and body mass index [BMI]), fluoroscopy time, KAP, and air-kerma at reference point (K
a,r). Moreover, the procedural complexity of each ERCP was determined and collected based on the 4-point American Society for Gastrointestinal Endoscopy (ASGE) complexity-grading system
18 (link)
19
. The radiation doses in ERCP and other gastrointestinal endoscopy procedures were compared. ERCPs performed for diagnosis and follow up of PSC included a significantly larger number of single image exposures compared to other ERCPs and were thus categorized separately. The effect of ERCP procedural complexity level and fluoroscopy system on radiation doses was then analyzed.
