Factors predicting asymptomatic splenic artery aneurysm expansion in patients managed conservatively: A single-center, retrospective, observational study.

Although splenic artery aneurysms (SAAs) are relatively rare in the general population, they represent the most prevalent type among visceral artery aneurysms. This study aimed to identify predictors of SAA expansion during follow-up and to contribute to a more comprehensive understanding of the natural history of SAAs. This single-center, retrospective, observational study included 137 patients with SAAs who were managed conservatively with computed tomography follow-up for a minimum of 1 year. The primary outcome was sac expansion, defined as any increase in the maximum sac diameter (≥1 mm) observed on follow-up computed tomography. The relationships between clinical variables and SAA expansion were examined. The incidence of SAA expansion was 35.0% (48/137). Eligible patients were categorized into 2 groups: the no-change (n = 89, 65.0%) and expansion (n = 48, 35.0%) groups. The 2 groups did not exhibit significant differences in demographic characteristics or risk factors, except for a higher likelihood of current smoking and portal hypertension in the expansion group. The prevalence of SAA wall calcification was notably higher in the no-change group (41/89 [46.1%] vs 8/48 [16.7%]; P  < .01). Multivariable Cox proportional hazards modeling revealed that SAA expansion was more likely to occur in current smokers (hazard ratio [HR], 4.34 [95% confidence interval [CI], 1.41-13.34]; P = .01) and in those with an initial maximum SAA diameter >14 mm (HR, 3.13 [95% CI, 1.61-6.08]; P < .01), but expansion was less likely to occur in patients with SAA wall calcification (HR, 0.27 [95% CI, 0.12-0.61]; P  < .01). SAA expansion was associated with wall calcification and initial maximum SAA diameters >14 mm. Further larger-scale studies are required to ascertain risk factors for rapid expansion, which could ultimately identify which categories of patients benefit most from early prophylactic intervention.