Intra-arterial catheter-directed CT angiography for assessment of endovascular aortic aneurysm repair

Abstract

Objective: To compare the efficacy and safety as well as associated image quality of catheter-directed CT angiography (CCTA) with a low dose of iodine contrast agent compared to intravenous CTA in patients undergoing endovascular aortic aneurysm repair (EVAR).

Methods: Retrospective data analysis of 92 patients undergoing EVAR between January 2009 and December 2017 was performed. Patients were divided in two groups; those receiving CTA (n = 59) after intravenous contrast agent application and those receiving CCTA (n = 33) via an intraarterial catheter placed in the descending aorta. Demographic and cardiovascular risk factors as well as renal function parameters before, immediately after and 6-60 months after EVAR were evaluated. As primary endpoint, changes in serum creatinine levels in the two groups were evaluated. Secondary endpoints encompassed complications associated with intraarterial catheter placement. Objective (signal-to-noise ratios) and subjective image quality (5-point Likert scale) were compared.

Results: Amount of contrast medium was significantly lower in CCTA compared to i.v. CTA (23 ± 7 ml vs. 119 ± 15 ml, p<0.0001). Patients undergoing catheter-directed CTA had higher baseline creatinine values compared to the group with intravenous iodine application (1.9 ± 0.6 mg/dl vs. 1.3 ± 0.5 mg/dl; p<0.0001). Follow-up serum creatinine levels however did not show significant alterations between the two groups (1.9 ± 0.4 mg/dl vs. 1.3 ± 0.5 mg/dl). No major complications were detected in the CCTA group. Signal-to-noise ratio (SNR) was comparable between i.v. CTA and CCTA (8.5 ± 4.6 vs. 7.7 ± 4.0; p = 0.37) and subjective image similarly revealed no differences with a good interobserver agreement (ICC = 0.647).

Conclusions: Catheter-directed CTA is safe and provides comparable image quality with a substantial retrenchment of the needed amount of iodine-based contrast medium. However, no benefit of the reduced contrast medium protocol with respect to renal function was observed.

Fig 1. Creatinine levels in the course of CTA at baseline (B), 1–7 days post CT imaging (I), preoperatively before endovascular aortic aneurysm repair (P) and at late follow-up (F).

Dotted line marks border towards elevated creatine levels beyond the reference values of 1.4 mg/dl.

Fig 2

Representative CTA images of a catheter-directed CTA (coronal maximum intensity projection in A, transversal image after i.a. contrast application in B), and in comparison of an intravenous CTA (coronal maximum intensity projection in C, transversal image after i.v. contrast application in D).