Splenic artery aneurysms: a retrospective review at Kaiser Permanente

Abstract

Purpose: Splenic artery aneurysms are the most common visceral aneurysms. While their incidence has grown with increased use of cross-sectional imaging, little is known about the natural history of these lesions. We sought to investigate patient characteristics, clinical risk factors, and growth patterns of splenic artery aneurysms in a large patient cohort. Materials and Methods: A patient list was retrieved from all Kaiser Permanente sites in Southern California via query of the electronic medical records system for the ICD9 code 442.83 (splenic artery aneurysm). Patient charts were retrospectively reviewed and demographics and medical comorbidities documented for each case. Cases of splenic pseudoaneurysm were excluded. Image reports were reviewed to find the oldest and most recent imaging in which the lesion was noted and the size was recorded for each. The patient chart was also reviewed for interventions in the form of open surgical or IR procedures. Results: 569 patient with splenic artery aneurysms were identified with females accounting for 78% (n¼442) of cases. The mean number of pregnancies in the 221 women with a documented obstetrics history was 3.9. The largest proportion of patients were White (69.1%), followed by Hispanic (22.5%), Asian (4.5%), and African American (3.8%). Current or former smokers made up 43.5% of all patients. The most frequent comorbidities in patients with splenic artery aneurysms were hypertension (67.4%), hyperlipidemia (55.9%), obesity (28.9%), diabetes mellitus (27.6%), atherosclerosis (25.3%), and liver cirrhosis (7.9%). 60 patients underwent a therapeutic procedure for their aneurysm including 39 with IR (primarily coil embolization), 18 with surgery, and 3 requiring both surgical and IR management. Longitudinal imaging data were available for 277 patients. 179 (65%) of these patients had aneurysms that were stable or decreased in maximum dimension. In the 98 patients who experienced interval aneurysm growth, the average growth rate was 0.95 mm/year. Conclusion: The preliminary results from our patient cohort represent the largest retrospective review of splenic artery aneurysms and aid in better defining the patient risk factors and natural history of these lesions.