Computed tomographic angiography- and magnetic resonance imaging-based diagnosis of abdominal aortic aneurysm with perianeurysmal fibrosis: from presence to consequences.

BACKGROUND

Abdominal aortic aneurysm (AAA) complicated by perianeurysmal fibrosis (PAF) can cause ureteral obstruction, chronic pain, and increased risk of rupture. However, the temporal relationship between AAA onset and PAF development, as well as the optimal management strategy [anti-inflammatory medication versus endovascular aneurysm repair (EVAR)], remains unclear. This study investigates the temporal sequence of PAF relative to AAA and evaluates treatment outcomes to define evidence-based management.

METHODS

This retrospective study reviewed patients with AAA from three tertiary medical centers between September 2015 and December 2021. Pre- and post-treatment computed tomography (CT) angiography and magnetic resonance images were analyzed to examine the prevalence, course, and clinical outcome of PAF.

RESULTS

A total of 29 AAA patients with PAF before treatment (of which, 22 patients were treated with EVAR, 5 patients with medical therapy, and 2 patients with open surgical repair) and 8 patients with 
de novo PAF after EVAR were included in this study. The median follow-up for all enrolled patients was 
4 months [IQR (interquartile range), 2-8 months]. The prevalence of PAF was 8.3%. Additionally, reduced PAF thickness was observed following medical therapy, while a decrease in the maximum AAA diameter was noted post-EVAR (from 58.4 to 56.1 mm, P=0.001). Furthermore, the medical treatment group reduced PAF thickness more than the EVAR group after adjustment for baseline thickness (from 12.7 to 5.5 mm, P=0.001). Interestingly, PAF secondary to AAA was observed in 2 patients, and de novo PAF was detected in 8 AAA patients post-EVAR with preoperatively PAF-free.

CONCLUSIONS

Medication significantly reduces PAF thickness in patients with pre-existing PAF. EVAR decreases the AAA diameter but may be associated with de novo PAF. The observed sequence of AAA preceding PAF suggests PAF as a secondary inflammatory response.