Background/Rationale:
Patients with AAA who have undergone EVAR of the abdominal aortic aneurysm require
indefinite follow-up since a 4-year complication rate after EVAR of up to 40% has been
described in some series.
In some patients a decrease in the diameters of the residual aneurysm sac after EVAR has
been described, which is known as remodeling.
CTA is the gold standard imaging technique for the follow-up of these patients, although
it has the disadvantage of using ionizing radiation and iodinated contrasts that are
nephrotoxic and can produce hypersensitivity reactions. Furthermore, there is no
consensus on which protocol is the most suitable (one phase, two phases or three phases).
Currently, in our hospital, three-phase CTA is being performed, as well as CTA with the
Split Bolus technique, which allows the acquisition of images in arterial and venous
phases in a single acquisition, thus reducing radiation doses; a correlation between both
techniques of 85.7-100% and a decrease in radiation doses of between 30-78% has been
described.
An alternative to CTA is CEUS that presents a sensitivity of 90.5% (22-100%) and a
specificity of 90.65% (71-100%) for the detection of endoleaks. It is a technique that
does not use ionizing radiation; furthermore, ultrasound contrasts are not nephrotoxic
and hypersensitivity reactions to them are exceptional. In addition, there are
publications concerning the determination of biomarkers in the follow-up of patients with
AAA both before and after treatment with EVAR.
Hypothesis:
Performing CEUS together with biomarker determination in patients with AAA treated by
EVAR would allow reducing the number of CTA to these patients; and, therefore, radiation
doses and the use of iodinated contrasts that may cause nephrotoxicity, as well as
hypersensitivity reactions.
Primary objectives:
1.
- To determine whether the combination of biomarker levels together with CEUS in
the follow-up of treated AAA patients is as effective as performing CTA to
detect endoleaks.
2.
- To validate the usefulness of CEUS together with biomarker determination in the
follow-up of these patients.
Secondary Objectives:
1.- To determine the cost-effectiveness of biomarkers in the follow-up of these patients.
To establish a protocol for the follow-up of patients with AAA treated with EVAR,
including biomarkers and CEUS.
3.-To reduce radiation doses in the follow-up of patients with AAA treated with EVAR.
Methodology:
Prospective observational study. Biomarker levels will be determined before (within 30
days prior to the procedure) and after stent implantation (24-48 h, 1 month, 3 months, 6
months and 1 year) together with contrast echography. In addition, a control CTA will be
performed to validate concordance. These biomarkers will be analyzed comparing the values
obtained in patients with endoleaks versus patients without endoleaks, as well as in
those with aneurysm remodeling.