Table 2. DUS Velocity and ABI Threshold Criteria for
Stratification of Risk for Thrombosis of Infrainguinal
Vein Grafts
Category
High-velocity
criteria (PSV)
Velocity ratio
(Vr)
Low-velocity
criteria (GFV) Change in ABI
Highest risk >300 cm/s >3.5 <45 cm/s >0.15
High risk >300 cm/s >3.5 >45 cm/s <0.15
Moderate risk 180–300 cm/s >2.0 >45 cm/s <0.15
Low risk <180 cm/s <2.0 >45 cm/s <0.15
Adapted from Bandyk DF, Seabrook GR, Moldenhauer P, Lavin J, Edward J, Cato R, et al. Hemodynamics
of vein gra stenosis. J Vasc Surg 1988;8:688-95.
Endovascular Lower Extremity Arterial Revascularization
➤ The SVS recommends clinical examination, ABI, and DUS within the first
month after aortoiliac segment endovascular therapy (EVT) to provide
a post-treatment baseline and to evaluate for residual stenosis. Clinical
examination and ABI, with or without the addition of DUS, should be
performed at 6 and 12 months and then annually as long as there are no
new signs or symptoms. (1-C)
➤ The SVS suggests clinical examination, ABI, and DUS within the first
month after femoropopliteal artery EVT to provide a post-treatment
baseline and to evaluate for residual stenosis. Continued surveillance at
3 months and then every 6 months is indicated for the following (2-C):
• Patients with interventions using stents because of the potential increased difficulty of
treating an occlusive vs. stenotic in-stent lesion.
• Patients undergoing angioplasty or atherectomy for critical limb ischemia because of
increased risk of recurrent critical limb ischemia should the intervention fail.
➤ The SVS suggests clinical examination, ABI, and DUS within the first
month after tibial artery EVT to provide a post-treatment baseline and
to evaluate for residual stenosis. Continued surveillance at 3 months
and then every 6 months should be considered. Those patients with a
deteriorating clinical vascular examination, return of rest pain, nonhealing
wounds or new tissue loss should undergo repeated DUS. (2-C)
