Deformation of the Femoropopliteal Segment: Effect of Stent Length, Location, Flexibility, and Curvature

J Endovasc Ther. 2016 Dec;23(6):907-918. doi: 10.1177/1526602816669135. Epub 2016 Sep 19.

Abstract

Purpose: To quantify the deformation behavior of the diseased femoropopliteal segment and assess the change to deformation behavior due to various stent placements.

Methods: The length and curvature changes of 6 femoropopliteal segments (the right and left superficial femoral and popliteal arteries) from 3 cadavers were measured in 3-dimensional space based on rotational angiography image data in straight leg and flexed hip/knee (50°/90°) positions before and after placement of nitinol stents of varying type (EverFlex, Misago, and BioMimics 3D) and length (60, 100, and 200 mm) in different locations along the arteries. Three-dimensional centerline data were extracted for the measurements.

Results: All 6 femoropopliteal cadaver segments displayed signs of peripheral artery disease. Hip/knee flexion resulted in vessel shortening and increases in the mean and maximum vessel curvatures in all cases. Location-specific results of the unstented arteries showed that magnitudes of vessel length and curvature change vary as a function of vessel length. The average shortening of the entire femoropopliteal segment due to flexion was observed at 10.7%±0.7%, which was reduced to 8.1%±0.9% after stent deployment. Average and maximum curvatures of the unstented segment increased due to flexion (average: 0.008±0.002 mm-1 to 0.019±0.006 mm-1, maximum: 0.030±0.009 mm-1 to 0.091±0.045 mm-1). After stent deployment, average and maximum curvatures of the flexed stented segments increased compared with the flexed unstented segments (average: 0.019±0.006 mm-1 to 0.022±0.004 mm-1, maximum: 0.091±0.045 mm-1 to 0.103±0.025 mm-1). The most flexurally stiff stent demonstrated the least ability to axially shorten during flexion of the leg at the knee joint.

Conclusion: The deformation characteristics of the femoropopliteal segment change in the presence of a stent, with the change to the deformation behavior dependent on stent type, stent length, location, flexibility, and intrinsic centerline curvature.

Keywords: biomechanics; cadaver; curvature; femoropopliteal segment; nitinol stent; peripheral artery disease; popliteal artery; rotational angiography; superficial femoral artery; vascular deformation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Video-Audio Media

MeSH terms

  • Aged
  • Alloys
  • Biomechanical Phenomena
  • Cadaver
  • Computed Tomography Angiography
  • Endovascular Procedures / adverse effects
  • Endovascular Procedures / instrumentation*
  • Female
  • Femoral Artery* / diagnostic imaging
  • Femoral Artery* / physiopathology
  • Hip Joint / diagnostic imaging
  • Humans
  • Knee Joint / diagnostic imaging
  • Male
  • Peripheral Arterial Disease / diagnostic imaging
  • Peripheral Arterial Disease / physiopathology
  • Peripheral Arterial Disease / therapy*
  • Pliability
  • Popliteal Artery* / diagnostic imaging
  • Popliteal Artery* / physiopathology
  • Posture
  • Prosthesis Design
  • Range of Motion, Articular
  • Stents*

Substances

  • Alloys
  • nitinol