Natural History of Patients with Popliteal Artery Aneurysms – Untreated and Treated

Abstract

Introduction: The definition of a popliteal artery aneurysm (PAA) is not well establised, the normal popliteal arterial diameter in a man is approximately 7 mm. There is limited knowledge about the natural history of PAA in patients. The suggested thresholds in contemporary series for elective vascular surgery ranges from 20-30 mm. The aim was to investigate the natural history in persons with PAA regarding growth as well as treatment rates and outcome. Methods: A retrospective medical chart review was performed on all patients with a PAA at a single center 2009-2016, with a catchment population of 1.2 million inhabitants. PAA was defined as “small” (diameter 12-15 mm, or defined as PAA by vascular surgeon) or “large” ( ≥16 mm). Comorbidity and outcome was analyzed on a patient-specific level, and the patients are classified according to their largest PAA diameter. Mean surveillance from diagnosis to follow-up or intervention was 4 years (range 1-10 years). Results: There were 174 patients (287 limbs) with a PAA diagnosis. 113 patients (65 %) had bilateral disease. Mean age was 72 years, 13 were women (8 %), most patients were current or former smokers (n=122, 70 %), 93 had abdominal aortic aneurysm (AAA) (53 %) and 92 (53 %) had lipid lowering treatment. (See Table). A larger proportion of patients with small PAA had concurrent PAA and (AAA) (73 % vs 49 %, p = 0.016). The proportion of small PAA was 30 % (86/287). The mean diameter at diagnosis for the 287 PAA was 21.6 mm. Growth rate was 0.38 mm/year in PAA < 16 mm, and 2.59 mm/year in PAA ≥16 mm. During the study period, 57/174 patients (33 %) were left untreated, however continuously surveilled. 117 persons were treated (67 %), 34 bilaterally. Most PAAs were treated with elective repair (120/151, 79 %), of them 12 % were small (flowchart). Among the 21 % (31/151) of PAAs treated for acute limb ischemia, 10/31 (32 %) were small. Only 5 patients (3 %) presented with a PAA rupture. During the study period 54/174 (31 %) patients died. Conclusion: PAA is more uncommon than AAA in the population; however, with increased awareness and targeted screening in risk groups at a vascular department, more patients can be diagnosed and evaluated for elective treatment. The growth rate is, as expected higher in larger PAAs. A considerable number of patients with acute limb ischemia have small PAAs. More concise thresholds for definition, surveillance and treatment of patients with PAA is called for in order to optimize the care flow of PAA patients.[Flowchart]View Large Image Figure ViewerDownload Hi-res image Download (PPT) Disclosure: Nothing to disclose