Rogier H. Kropman1
, Herman J. Zandvoort2
, Danyel A. van de Heuvel1
, Jan Wille1
, Frans L. Moll2
, Jean-Paul P. de Vries11Vascular surgery, St Antonius Hospital, Nieuwegein, Netherlands; 2University Medical Center, Utrecht, Netherlands.OBJECTIVES:
It is not clear which characteristics of an asymptomatic popliteal artery aneurysm (PAA) will increase the risk for acute thrombosis. Besides PAA diameter, hemodynamic changes in the popliteal artery during knee movement may play a role.
METHODS: A single center prospective study of consecutive patients with PAAs presenting from January 2010 to April 2012. Computed tomography angiography was used to perform measurements of the PAA during extension and 90 degrees flexion of the knee in a specially prepared brace. After semi-automated segmentation of the popliteal lumen, a center lumen line (CLL) was automatically constructed. Popliteal aneurysm diameter and length, lumen area and the degree of angulation were measured.
RESULTS: Thirteen men with 16 asymptomatic PAAs were included. Median PAA diameter was 28mm (IQR 19 - 39) and median PAA length 63mm (IQR 51 - 112). Median lumen area of popliteal artery direct proximal of the PAA was 57mm2 (IQR 44 - 87) in extension versus 51mm2 (IQR 38 - 73) during 90 degree flexion (p=0.007). Direct distal of the PAA was the median lumen area 46mm2 (IQR32 - 66) in extension compared to 38mm2 (IQR 30 - 62) in flexion (p=0.03). The greatest decrease in lumen area (direct proximal or distal from the aneurysm) after flexion was significant larger in PAAs ≥30mm compared with PAAs <30mm (p< 0.05). Median degree of proximal angulation of the popliteal artery was 48 degrees in extension (IQR 27 - 61) and 75 degrees during flexion (IQR 46 - 99) (p=0.02). Median degree of distal angulation was 31 degrees (IQR 21 - 42) after extension versus 62 degrees (IQR 33 - 81) during flexion (p=0.03).
CONCLUSIONS: Knee bending in patients with PAAs will lead to a significant reduction in lumen area and a significant change in degree of angulation proximal and distal of the PAA, which may be a cause for increased thromboemboli. A significant decrease in lumen area was seen in PAA ≥30mm compared with PAA <30mm after flexion of the knee.
AUTHOR DISCLOSURES: J. P. de Vries: Nothing to disclose; R. H. Kropman: Nothing to disclose; F. L. Moll: Nothing to disclose; D. A. van de Heuvel: Nothing to disclose; J. Wille: Nothing to disclose; H. J. Zandvoort: Nothing to disclose.
Posted April 2013