Interventional echocardiographers receive higher radiation doses than interventional cardiologists

In structural heart procedures such as mitral valve repair (TEER) and left atrial appendage closure (LAAO), the interventional echocardiographer guides the case with a transesophageal probe, standing near the patient and the x-ray source, where scatter comes from. Two studies have measured what that position receives.

Higher doses than the cardiologist at the table

McNamara and colleagues put real-time dosimeters on interventional echocardiographers, interventional cardiologists and sonographers through 30 consecutive LAAO and 30 consecutive TEER procedures at one center.¹ Across all 60 cases, the median dose per case was 10.6 µSv for the echocardiographer and 2.1 µSv for the interventional cardiologist.

• LAAO: 10.6 µSv against 3.5 µSv, 3.0 times higher.
• TEER: 10.5 µSv against 0.9 µSv, 11.7 times higher.

The echocardiographer received more than 20 µSv in 30% of LAAO cases and 27% of TEER cases. The authors chose that mark because it is roughly ten times the mean dose previously reported for interventional cardiologists across a range of procedures. Sonographers received low doses throughout.¹

The waist and lower body

Kataoka and colleagues modeled where scatter lands on an echocardiographer’s body and checked the model against measurements in 79 procedures (44 TEER, 35 transcatheter aortic valve replacements).² The highest exposure fell on the right half of the body, especially the waist and lower body, from radiation scattered at the bottom edge of the patient bed. Waist exposure was higher in TEER than in valve replacement. The authors conclude that interventional echocardiographers, especially young women, should be taught about this exposure, and they note that the ovary is in the exposed area.

Shielding the echo position

In a phantom study of EggNest^® Complete, scatter at the echo or EP implanter position was 96% lower than with standard cath lab shielding, averaged over five C-arm angulations. The study was sponsored by Egg Medical, and its authors note the results need confirming in clinical studies.³ See the study on the Evidence page.