Introduction: The popliteal artery (PA) is, after aorta, the most common site for aneurysm formation. Why the PA is more susceptible than other peripheral muscular arteries is unknown. We hypothesised that the wall composition, which in turn affects wall properties, as well as the circumferential wall stress imposed on the arterial wall, might differ compared to other muscular arteries. The aim was to study the circumferential wall stress of the PA in healthy subjects with the adjacent muscular common femoral artery (CFA) as a comparison.
Material and Methods: Ninety-four healthy subjects were included in this study (45 males, range 10-78 years and 49 females, range 10-83 years). The lumen diameter (LD) and intima-media thickness (IMT) in the PA and CFA were investigated with a Philips P700 ultrasound device. Together with blood pressure the circumferential wall stress was defined according to the law of Laplace adjusted for IMT.
Results: The diameter increased with age in both PA and CFA (P<.001), with males having larger diameter than females (P<.001). IMT increased with age in both PA and CFA (P<.001), with higher IMT values in males only in PA (P<0.001). The calculated wall stress was unchanged with age in both arteries, but lower in PA than in CFA in both male and female subjects (P<0.001).
Conclusion: This study shows that the popliteal and common femoral artery wall stress is maintained during ageing, probably due to compensatory remodeling response with an increase in arterial wall thickness. However, the stress imposed on the popliteal artery wall is quite low, indicating that other mechanisms than wall stress contribute to the process of pathological arterial dilatation in the popliteal artery.