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

Abstract

Objective: 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.

Material and methods: 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.

Results: 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).

Conclusions: 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.

Keywords: Aortic aneurysm; Dose archiving system; Endograft; Fusion imaging; Hybrid room; Radiation.