Introduction
The noninvasive nature of endovascular procedures and successful early
results were the main reasons of endovascular popularity all around the
world (1-3). As the endovascular procedures has potential device related
complications and aneurysm related events has not completely vanished,
lifelong surveillance is mandatory. The follow up protocols should
diagnose complications requiring reintervention, earlier enough to have
time for elective treatment. Increasing awareness of the risks and costs
of a lifelong computed tomographic angiography (CTA) surveillance, led
to find out convenient follow up modalities offering non-invasiveness,
cost saving, safety, availability and accuracy.
CTA still is the gold standard as a diagnostic tool and preoperative
measurements in aortic aneurysms for endovascular abdominal aortic
aneurysm repair (EVAR), however since potential malignancy risk is not
zero and there is risk of nephrotoxicity (7-12%)(4-8), as it may not be
a suitable follow-up modality. Also regarding health economics, almost
one third of the EVAR cost can be attributed to post-EVAR radiologic
imaging (9-12). The Markov model base-case analysis results show that
annual follow-up with Color Doppler Ultrasonography (CDUS) only is the
strategy with the lowest cost (12). There are conflicting conclusions
among the studies about CDUS as a surveillance modality after EVAR,
maybe because of the heterogeneity of study designs, equipment,
techniques, or training (9,10,13-26). The findings of the nine
systematic reviews of diagnostic accuracy show that for CDUS the pooled
sensitivity for detection of all types of endoleaks ranged from 65 to
96% and the pooled specificity ranged from 90 to 97% (12). Anyway,
current guidelines suggest CTA and CDUS as follow up modalities in case
of different scenarios (4,5).
Eventhough life-long surveillance after EVAR is universally accepted,
there are currently no ideal frequency or standart regimen for imaging
protocols. Because of this heterogeneity, almost every clinic has its
own protocol. Modified surveillance protocols have been proposed to
eliminate repetitive CTA examinations. In this study, we evaluated CDUS
as the primary follow-up modality for post-EVAR patients by comparing
the results with CTA.