The Protego shield provides protection from total body radiation exposure (RE) for operators performing coronary and structural heart procedures, allowing procedural performance without the need for personal lead aprons, a new study finds. Additional findings from the single-center, two-group cohort study suggest that the Protego shield could reduce catheterization laboratory occupational health hazards. “The present findings based on a large number of patients undergoing a broad spectrum of procedures (diagnostic catheterizations, percutaneous coronary interventions and structural heart procedures) are consistent with and extend those of prior studies in smaller patient cohorts (16-20), documenting that the Protego radiation shielding system provides unprecedented RE protection and reduced >99% compared to standard methods,” David G. Rizik, MD, chief scientific officer at HonorHealth in Scottsdale, Arizona, and colleagues wrote in a manuscript reporting the results that was published online in Cardiovascular Revascularization Medicine, simultaneous with his presentation Tuesday at Cardiovascular Research Technologies (CRT) 2024 in Washington, D.C . Radiation exposure reduced In the manuscript, Rizik and colleagues revealed that compared to standard protection, the Protego system was able to reduce operator RE, which was significantly lower at both thyroid level (0.63±2.03 vs 66.4±54.2 microsievert [µSv], p<0.001) and the waist (0.33±1.37 vs 142.5±149.1 µSv, p<0.001). “Zero” total RE was documented by the real-time dosimetry system RaySafe in 64% (n=32) of transcatheter aortic valve replacement (TAVR) cases and 73.2% (n=183) of the coronary cases utilizing Protego. In contrast, standard protection did not achieve “zero” exposure in a single case. These differences in RE were achieved despite higher fluoroscopy times in the Protego arm (14.3 ± 12.5 vs. 11.9 ± 8.6 minutes, p=0.015). Per-case procedural exposure measured by Dose Area Product was higher in the Protego group compared to standard protection (115.4±139.2 vs 74.9±69.3 Gy*cm2), with 100% procedural success achieved in the Protego group. “The full range of C-arm angulations was easily accommodated,” Rizik and colleagues wrote. “In no case did the shield system impair procedural performance with respect to vascular access, utilization and manipulation of catheter equipment, or observation and communication with the patient or staff. They added that 76% of the coronary cases in the Protego group involved radial access, and 96% of the TAVR cases in the Protego group involved both femoral and radial access. Study limitations Commenting on the study’s limitations, the study’s authors said that RE measurements beneath the aprons were not expected to yield informative data. Therefore, dosimeters were deployed outside the lead aprons and the goal was to analyze total body exposure. As so measured, the present findings emphasize the benefits of the more comprehensive shielding afforded by the Protego shield. The research team also pointed out that patient radiation doses (i.e., total fluoroscopy time and DAP) were significantly higher in the Protego group. These differences, not seen in the TAVR comparisons between Protego and Standard Protection, were noted only in the coronary case comparisons. Specifically, there were more coronary interventions performed in the Protego arm of the coronary cohort than in the Standard Protection arm (65.2% vs 46%). “We speculate this may be due to the sense that the protective benefits of the shield led operators to preferentially seek to use Protego for more complex (and thus RE intensive) percutaneous coronary interventions,” said the study authors. “Most importantly, the higher procedure based RE in the coronary group serves to emphasize the protective capabilities of the Protego shield, for the reductions in operator RE were dramatically lower than coronary cases in the control arm which had lower procedure based (DAP) exposure.” Methodology This single-center, two-group cohort study compared physician RE to the primary operator utilizing the Protego shield (n= 300 cases) or standard protection alone (personal lead apron 0.5 mm, thyroid collar, and leaded glasses, together with ceiling drop-down shield, n=150 cases). Overall, the study analyzed 350 coronary procedures including four chronic total occlusions, eight cases involving unprotected left main intervention, and 100 TAVR cases. The Protego radiation shielding system consists of rigid shields above and below the table, integrated with interconnecting flexible radiation resistant drapes. The standard protection “control” cohort represented consecutive cases by multiple operators who similarly wore dosimeters at waist and thyroid levels. Procedures were performed in a single cardiac catheterization laboratory equipped with a floor-based single plane C-arm (Axiom Artis, Siemens, Munich) The primary outcome was physician operator RE measured in µSv. “Zero” RE was defined as individual cases in which both thyroid and waist badges showed no detectable RE. Photo Credit: Jason Wermers/CRTonline.org Photo Caption: David G. Rizik, MD, presents results of a study of the Protego radiation shield, an alternative to lead aprons in the catheterization laboratory, on Tuesday at CRT 2024 in Washington, D.C.