Safety of Utilizing Ultrasound as the Sole Modality of Follow-Up after Endovascular Aneurysm Repair

Abstract

Post-EVAR, surveillance with CTA remains the most common practice, per SVS guidelines. Chronic exposure to both radiation and IV contrast has raised concerns about long-term CTA follow-up. As we have selectively used US as a sole modality for post-EVAR surveillance, we sought to review our outcomes in this subset of patients. Retrospective review of our institution's Vascular Database identified 213 EVAR patients from 2013 to 2021. FEVAR and snorkel reconstructions were excluded. Patient demographics/outcomes, AAA characteristics, and FU modalities and outcomes were analyzed. Unpaired student t-test, ANOVA, and Chi-square test were used to assess group differences. Eighty-five of the 213 EVAR patients (39.9%) were lost to FU within 3 months. Among the 128 remaining patients, 91 underwent FU using initial US, while 37 patients underwent post-EVAR FU initially using CTA. There were no significant differences (p > 0.05) between patient age (75.5 ± 9.4 vs. 75.3 ± 8.5), BMI (27.7 ± 5.4 vs. 28.9 ± 7.4), or mean AAA size (5.6 ± 1.1 vs. 5.9 ± 1.2) in US-surveilled and CT-surveilled groups respectively. Of the 91 patients initially surveilled with US, 15 patients demonstrated endoleak and/or AAA growth (>5 mm). The 15 patients with US demonstrated-endoleak and/or growth underwent confirmatory CTA with 3 patients eventually requiring EVAR revision. Among 37 patients initially surveilled with CT, 10 demonstrated significant growth and 2 patients eventually required EVAR revision. There were no patients with AAA rupture during post-EVAR surveillance. Follow-up data was analyzed among a select lower-risk group of patients (pre-operative AAA diameter ≤ 5.5 cm, BMI ≤ 30, and no endoleak at completion of EVAR). Among this group, there were no surveilled patients that required EVAR reintervention regardless of surveillance modality (US n=32; CT n=4). The average follow-up was 29.5 ± 26.4 months in the US group and 26.4 ± 22.3 months in the CT group (p > 0.05). Although initial CT surveillance following EVAR remains ideal, in select lower-risk patients, ultrasound is a viable alternative even for the initial post-procedure study. Advantages include decreased radiation exposure and cost. Our data suggest that US is a safe sole modality for surveillance following EVAR in selective patients.