Is assessment of popliteal artery diameter in patients undergoing screening for abdominal aortic aneurysms a worthwhile procedure

Purpose. The aim of this study was to assess whether screening of popliteal arteries in patients undergoing ultrasound screening of their abdominal aortas was worthwhile. Methods. All male patients undergoing ultrasound screening for abdominal aortic aneurysm (AAA) during the period February 2000 to June 2002 were offered scanning of their popliteal arteries. All scans were performed by a single, trained operator using a Sonosite 180. Results. Four hundred and forty-nine patients underwent screening and thus 898 popliteal arteries were assessed. The mean aortic diameter was 2.1 standard deviations (SD) 0.5 cm and the tipper limit of normal (2 SD) was 2.7 cm. The mean diameter of the popliteal arteries was 0.74 SD 0.11 and the upper limit of normal was 0.96 cm. Thirty patients had aortic diameters greater than 2.5 cm (ectatic or aneurysmal aortas) but based on a popliteal diameter of 2 cm, no popliteal aneurysms were detected. However, 39 (4.3%) popliteal arteries measured >= 1 cm (> mean + 2 SD); 3/60 (5%) in the ectatic/AAA subgroup and 361838 (4.3%) in the non-AAA subgroup, Conclusions. This study has shown that, using conventional definitions, the imaging of popliteal arteries during screening for AAAs does not detect any popliteal aneurysms and is thus of limited value. However, if a definition of popliteal aneurysm of >= 1 cm (based on mean + 2 S/D) is used then 391898 (4.3%) of arteries would be regarded as having abnormal diameters and may require surveillance.