Dyeless EVAR for Ruptured AAA: From Dream to Reality

In their paper, Masana Llimona et al. present a case report of ruptured abdominal aortic aneurysm (rAAA) treatment by endovascular aortic aneurysm repair (EVAR) using an intra-operative fusion imaging technique after unenhanced computed tomography (CT) pre-operative examination in a patient with acute renal failure (ARF). This approach is quite original and must be kept in mind in daily clinical practice, not only for ARF but also for severe iodinated contrast media (ICM) allergy. Advances in CT systems have improved image quality of unenhanced CT examinations tremendously, and in selected cases elective EVAR can be planned, particularly in patients with ICM allergy or with chronic kidney disease (CKD). Many of the other details needed for EVAR planning can be provided by good quality colour flow imaging (CFI). ARF is a serious complication after rAAA repair and requires long term dialysis in up to 17% of cases, so all the measures useful for contrast induced nephropathy (CIN) prevention must always be put in place. Unenhanced CT with the most modern equipment, in addition to detecting AAA rupture by showing surrounding retroperitoneal haemorrhage, is able to precisely locate the renal arteries and iliac bifurcations and their relationships to nearby bone structures. Image fusion for urgent EVAR of rAAA after CT angiography was first described by Ziza et al. in 2015; Knipp et al. in 2010 demonstrated a significant reduction in the use of ICM for endovascular repair of rAAA with carbon dioxide (CO2) as the principal contrast agent, but the combined use of the two methods has not yet been studied in this field. Regarding the approach adopted by Masana Llimona et al., we would like to make the following comments. The total amount of ICM used for the whole procedure was 47 mL; however, today it is possible to perform an EVAR procedure with even less ICM for those who do not have fusion imaging readily available in the operating room (i.e., perform intra-operative angiography with diluted ICM, locate the lower renal artery with vertebral bone mark on