Cap, Patient Shield Provide Substantial Reductions in Operator Radiation Exposure
Integration of 2 simple protection devices—a 2-piece lead drape over the patient and a lightweight, disposable cap worn by the operator—into coronary angiography and intervention procedures reduces operator radiation exposure by more than 70%, according to a study published in the August 2015 issue of Circulation: Cardiovascular Interventions.
Researchers led by Sanjit S. Jolly, MD, MSc, of Hamilton General Hospital (Hamilton, Canada), enrolled 228 patients (mean age 65.7 years; 32% women) at their center who were referred for PCI or coronary angiography with a high likelihood of undergoing PCI. Patients were randomized to usual care or to undergo the procedure while wearing a drape (0.5-mm lead equivalent), which was made of 2 pieces exceeding the patient’s width and featured 2 semicircular cutouts to accommodate femoral vascular access (UltraRay Medical; Oakville, Canada). All 10 operators also wore the nonlead No Brainer cap (Worldwide Innovations & Technologies; Kansas City, KS), which contains bismuth and barium to block radiation.
Most cases (71.5%) involved PCI with stenting, whereas diagnostic angiography alone was performed in 26.0% of patients. Radial access was used in 75.4% of patients, and 7.9% of procedures were planned PCI for chronic total occlusion. Fluoroscopy time, air kerma, and contrast volume were similar in both treatment groups.
Compared with usual care, use of the lead shield resulted in a 76% reduction in operator mean left chest radiation exposure and a 72% reduction in dose as a function of air kerma (table 1).
The lead drape was well tolerated by patients, with only 1 patient who weighed 52 kg asking for it to be removed due to discomfort.
As measured by dosimeters inside and outside the surgical cap, operator mean left temporal radiation exposure also was reduced with its use, regardless of lead drape use (table 2).
Median operator comfort level with cap during the procedure on a 1- to 10-point scale was 9.
Results were consistent across multiple subgroups, but a greater reduction in radiation exposure was observed in patients treated via the femoral approach (P = .002 for interaction).
It’s the Little Things
In a telephone interview with TCTMD, Dr. Jolly said that both Canadian sites at which he works now use some type of lead drape on all patients receiving coronary angiography or PCI. “The cost is actually quite small,” he noted, adding that though cap use is not required, most operators are using each cap for months at a time before throwing them away. “Wearing a lead cap that weighs a kilogram is very cumbersome, whereas you barely notice a cap that weighs 100 grams,” he said.
Aesthetics should not be overlooked, Dr. Jolly commented. “If somebody wears something and is made fun of and [they] can’t get their colleagues to use [it], it’s going to die very quickly,” he said, “whereas something that’s seamless and looks like a standard surgical cap and happens to be protective will be taken up much more quickly.”
Pointing to a survey published by the Society for Cardiovascular Angiography and Interventions earlier this year, Dr. Jolly said the issue of radiation safety remains important for cath lab operators. “A number of operators in the US are actually going over their dose limit and have to stop and take a break out of the lab,” he said. “Also, a substantial proportion of operators are not wearing their [radiation dosimeter] badges… Finally, orthopedic injuries related to lead are so high. Measures that we can do to reduce radiation at its source or before it gets to the operator are very important for the operators’ health.”
Ultimately, “it’s the small interventions [that] seem to have large benefits in terms of reducing radiation exposure,” Dr. Jolly observed.
Imaging Only When Justified
In an email to TCTMD, Reza Fazel, MD, of Brigham and Women’s Hospital (Boston, MA), said he uses protective caps and a disposable version of the patient apron “in certain situations, such as a left radial approach for angiography or PCI where leaning over the patient exposes operators to more radiation.”
“There has been increasing focus on the issue of radiation safety over the past decade or so,” but overall physician awareness is still “far from ideal,” he said. “However, it is encouraging to see efforts to bridge this knowledge gap, including increased visibility of this topic in peer-reviewed journals, increased time allotted to this topic at national scientific meetings, as well as more organized educational campaigns such as Image Wisely.”
Future priorities should be “ensuring that imaging studies are clinically necessary and appropriate,” Dr. Fazel said. “The ACC/AHA Appropriate Use Criteria were developed to promote justification and help avoid inappropriate imaging. However, we still don’t have a balanced, fair system for implementing AUC in clinical practice, and I believe we need to figure out how to develop such a system.”
Alazzoni A, Gordon CL, Syed J, et al. Randomized controlled trial of radiation protection with a patient lead shield and a novel, nonlead surgical cap for operators performing coronary angiography or intervention. Circ Cardiovasc Interv. 2015;8:e002384.
- The study was sponsored by McMaster University, the lead drapes were provided by UltraRay Medical, and the caps were provided by Worldwide Innovations & Technologies.
- Drs. Jolly and Fazel report no relevant conflicts of interest.