Vascular surgeons from the medical center that pioneered use of the radiation-lowering Fiber Optic RealShape (FORS) imaging modality reported a 62% technical success rate using the first-generation version of the technology across the first 50 procedures performed.
The data were reported at the 2022 Vascular Annual Meeting (VAM) in Boston (June 15–18) by Giuseppe Panuccio, MD, from University Heart and Vascular Center Hamburg in Germany, who told those gathered his team’s work with the system represented “moderate success cannulating aortic branch vessels and a high potential in reducing radiation exposure.”
The cases involved—mostly branched and fenestrated endovascular aneurysm repairs (B/FEVARs) all performed by three operators—were carried out between February 2020 and February 2021 in Hamburg using the FORS guidewire and a pair of FORS catheters (with conventional catheter compatibility). A total of 186 tasks were included in the study.
Challenges related to vessel catheterization, including stenosis >50% and angulation >45º, were assessed, as were the time required for each catheterization as well as radiation exposure.
Panuccio reported no FORS-related complications as he delivered the data showing a 62% rate of technical success, with 38% of the cases abandoned. “What was really impressive was that when FORS was successful, the amount of radiation required for catheterization was really minimal,” he said. “You have to consider that inside of the radiation needed for catheterization, we consider also the angiography that was performed before the catheterization.”
Reduced technical success was associated with cannulation of renal arteries, vessel angulation, and vessel stenosis, he told VAM 2022. Catheterization tasks through a branch of a complex aortic endograft frequently required a non-FORS catheter—technical success with the FORS catheter was 18% (p<0.001), Panuccio revealed. Successful FORS task catheterization was associated with a significant three-fold radiation exposure reduction (dose area product 12.5 vs. 4.4 cGycm2, p<0.001). Further, success ranged from 81% at the superior mesenteric artery to 42% at the celiac trunk. Panuccio said the operators also encountered problems with branches (success rate of 52%), angulation (33%), and stenosis greater than 50% (17%).
“The reduced success rate observed in challenging anatomy appears related to the limited availability of FORS catheter shapes and its device properties,” the authors concluded. “Iterative FORS improvements are underway to address these limitations with the hopes of increasing success.”
Panuccio said the researchers expect visualization improvements when using conventional catheters to be forthcoming. Further evaluation is ongoing through a FORS multicenter registry, which includes nine transatlantic centers and more than 350 enrolled patients.
Gustavo Oderich, MD, a moderator of the session in which Panuccio was presenting, commented on the “changing paradigm” the technology and associated data represented, and also queried Panuccio on how many of the tasks he and his colleagues couldn’t complete were down to not having the proper wire or catheter versus an inability to see other landmarks.
“One of the main limitations was the material properties—but also how we learn how to use it,” Panuccio said. “You have to completely reset how you use the wire and with which catheter is the best combination. Material properties have to be developed, improved.”
