Radiation Dose Reduction During EVAR: Results from a Prospective Multicentre Study (The REVAR Study)

Abstract

To evaluate radiation exposure in standard endovascular aneurysm repair (EVAR) using intra-operative guidance with pre-operative computed tomographic angiography (CTA) fusion and strict ALARA guidelines in a modern hybrid room. Between February and November 2016, consecutive patients with AAA undergoing EVAR with a bifurcated device in a hybrid room under fusion imaging guidance were prospectively enrolled in six aortic centres from the United States (n = 1), Europe (n = 4), and Japan (n = 1). Demographic data including body mass index (BMI), indirect dose area product (DAP), cumulative air kerma (CAK), variables influencing dose delivery, and contrast media volume were collected. 85 patients (90.4% males) were included. The median age was 75 (IQR 69–81), with a median BMI of 27.4 (IQR 24.7–30.6). Median DAP and CAK were 14.7 (IQR 10.0–27.7) Gy·cm2 and 107 (IQR 68.0–189.0) mGy, respectively. The median contrast volume was 47 mL (IQR 35–70) (equivalent to 14.1g of iodine [IQR 10.5–21.0]). Median DAP per centre was 28.1 (n = 16, IQR 12.6–47.1), 15.9 (n = 11, IQR 11.9–22.5), 14.2 (n = 12, IQR 10.9–25.7), 20.2 (n = 18, IQR 7.0–39.5), 10.3 (n = 27, IQR 8.2–14.7) and 26.5 (n = 1) Gy·cm2. In multivariable analysis, collimation was the only factor that was significantly associated with DAP reduction, (coefficient = −0.014 per percentage of collimation, 95% CI −0.019 to −0.008, p < .001). With adherence to the ALARA principle and routine application of fusion imaging guidance for EVAR, low radiation exposure compared with the published literature can be achieved in a real world setting.