Systematic Review of the Co-Prevalence of Arterial Aneurysms Within the Vasculature

Aneurysms are considered focal manifestations of a systemic vascular condition, and various studies report co-prevalence of aneurysms in different vascular beds. Insight into profiles of patients at risk of multiple aneurysms is lacking, and few clinical algorithms exist if additional screening is indicated. This systematic review assessed the co-prevalence of aneurysms in different vascular beds and analysed putative risk factors for multiple aneurysms.

Medline, Embase, and Cochrane libraries were searched up to February 2020 for studies reporting co-prevalence of aneurysms in different vascular beds using the keywords: "aneurysm", "co-prevalence", or synonyms. All studies were reviewed by two authors independently. Studies were excluded if they described concomitant treatment of multi-aneurysms, or if the aneurysm was reported solely bilateral, post-dissection, mycotic, traumatic, iatrogenic, or caused by a connective tissue disease. Radar plots were used to indicate studies that found an association between the investigated features and aneurysm co-prevalence against those that did not.

Thirty-two studies met the inclusion criteria, describing in total 16 353 patients of whom 2 015 had at least one additional aneurysm. The weighted co-prevalence was 16.9% (95% confidence interval [CI] 11.8-22.6), I² > 90%. At least 19 combinations of aneurysms were described, mostly derived from retrospective studies. Seventeen of 32 (53%) studies described concurrent aneurysms in patients with an abdominal aortic aneurysm. Predominantly positive associations were found for higher age, hypertension, stenotic disease, presence of multiple (at least three) aneurysms, and primary aneurysm size.

Approximately one in six patients with a primary aneurysm harbours an additional aneurysm, increasing to one in four if the patient has a popliteal artery aneurysm. Higher age, hypertension, stenotic disease, presence of multiple (at least three) aneurysms, and primary aneurysm size were predictive of aneurysm co-prevalence. These clinical predictors may assist when deciding whether a patient with a primary aneurysm needs to be screened for additional aneurysms.