Table 3

PARC Lesion and Vessel Characteristics and Definitions

Lesion or VesselTermDefinition
Significant peripheral artery stenosisMild<50%
Moderate50%–69%
Severe70%–99%
Occluded100%
Lesion lengthFocal≤1 cm
Short>1 and <5 cm
Intermediate≥5 and <15 cm
Long≥15 cm
Degree of lesion
calcification (26)
Focal<180° (1 side of vessel) and less than one-half of the total lesion length
Mild<180° and greater than one-half of the total lesion length
Moderate≥180° (both sides of vessel at same location) and less than one-half of the total lesion length
Severe>180° (both sides of the vessel at the same location) and greater than one-half of the total lesion length
Anatomic level of LE-PADAortoiliacAortoiliac (distal limit bottom of pelvic rim in the AP view by angiography or inguinal ligament)
FemoropoplitealFemoropopliteal (distal limit is origin of anterior tibial artery)
TibialpedalTibialpedal (anterior tibial and below including foot arteries)
Aortoiliac segmentInfrarenal abdominal aorta
Common iliac artery
Internal iliac artery
External iliac artery
FemoropoplitealCommon femoral artery
Profunda femoris artery
Superficial femoral artery
P1 segment (above knee popliteal artery): from Hunter’s canal to proximal edge of patella
P2 segment: from the proximal part of patella to center of knee joint space
P3 segment (below knee popliteal artery): from the center of knee joint space to origin of anterior tibial artery
TibialpedalTibial-peroneal trunk (from the origin of the anterior tibial artery to the bifurcation of the posterior tibial and peroneal artery)
Anterior tibial artery
Posterior tibial artery
Peroneal artery
Plantar pedal loop
pedal vessel
PT, DP
Target lesionAny vascular segment treated or attempted to be treated during the trial procedure with the index device. The target lesion is the treated segment including 10 mm proximal and ending 10 mm distal to the index device or therapy (stent, balloon, or atherectomy catheter).
TLRTLR is any repeat intervention of the target lesions (plus 10 mm proximal and distal to the index device) or surgical bypass of the target vessel performed for restenosis or other complication involving the target lesion. If the target vessel is occluded and bypass is done to another artery below the knee, this should be considered TLR. In the assessment of TLR, angiograms should be assessed by an angiographic core laboratory (if designated) and made available to the clinical endpoints committee for review.
Target vesselAny vessel (e.g., noncardiac or nonintracranial) that contains the target lesion treated with the study device. The target vessel includes the target lesion as well as the entire length of native vessel upstream and downstream from the target lesion, including side branches.
Target limbAny symptomatic limb that contains the target lesion and all vessels from aortic bifurcation to the foot.

The majority of the anatomic classifications were adapted from Diehm et al. (7).

DP = dorsalis pedis artery; PT = posterior tibial artery; QCA = quantitative coronary angiography; TLR = target lesion revascularization; other abbreviations as in Table 2.

  • Lesion stenoses are clinically based on visual angiographic assessments. For clinical trials, lesion stenosis may be evaluated with core-laboratory QCA.

  • PARC recommends continued efforts to encourage documentation of pedal anatomy in relevant patients.

  • It is desirable to obtain selective tibial imaging evaluating the vascular supply to tissue at risk with categorization of pedal/arcuate vessels in patients with tissue loss.