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.