Reduction of radiation exposure in transcatheter atrial septal defect closure: How low must we go?

BACKGROUND: Cardiac catheterization relies on X-ray imaging. Most procedures are now standardized. Interventionists must strive to minimize radiation exposure to reduce the risk of induced cancers.

AIMS: To describe the radiation level in our institution, and evaluate the components contributing to radiation exposure, during transcatheter atrial septal defect (ASD) closure.

METHODS: Radiation doses for ASD closure performed between January 2009 and November 2015 were reviewed retrospectively. Data on fluoroscopic time, dose area product (DAP), DAP/kg of body weight and total air kerma were collected.

RESULTS: One hundred and seventy-four consecutive patients were included. Procedural success was 98.3%. Median procedural and fluoroscopic times were 15minutes and 1.2minutes, respectively. Median total air kerma, DAP and DAP/kg were 9.2 mGy, 88.3μGy.m2 and 3.2μGy.m2 /kg, respectively. Risk factors associated with higher DAP were older age, larger ASD and device, need for balloon calibration, occurrence of complications and use of higher frame rate. Reduction of frame rate to 7.5 frames/second alone reduced by a factor of 2 the median DAP, DAP/kg and air kerma (99 vs 43μGy.m2 , 3.5 vs 1.7μGy.m2 /kg and 11 vs 4.8 mGy, respectively; P<0.001).

CONCLUSIONS: A low dose of radiation can be achieved for transcatheter ASD closure, even in complex ASDs, by following these recommendations: reduction of frame rate; avoidance of lateral view and cine acquisition; and limitation of fluoroscopic time by avoiding unnecessary manoeuvres and using echocardiographic guidance as much as possible.