The Fontaine stages, were introduced by René Fontaine in 1954 to define severity of chronic limb ischemia:
Stage I: asymptomatic
Stage IIa: intermittent claudication after walking a distance of more than 200 meters
Stage IIb: intermittent claudication after walking a distance of less than 200 meters
Stage III: rest pain
Stage IV: ulcers or gangrene of the limbThe Rutherford classification was created by the Society for Vascular Surgery and International Society of Cardiovascular Surgery, introduced in 1986 and revised in 1997 (and known as the Rutherford classification after the lead author, Robert B. Rutherford). This classification system consists of four grades and seven categories (categories 0–6):
Grade 0, Category 0: asymptomatic
Grade I, Category 1: mild claudication
Grade I, Category 2: moderate claudication
Grade I, Category 3: severe claudication
Grade II, Category 4: rest pain
Grade III, Category 5: minor tissue loss; ischemic ulceration not exceeding ulcer of the digits of the foot
Grade IV, Category 6: major tissue loss; severe ischemic ulcers or frank gangreneModerate to severe PAD classified by Fontaines stages III to IV or Rutherfords categories 4 to 5, presents limb threat (risk of limb loss) in the form of critical limb ischemia.Recently, the Society for Vascular Surgery came out with a classification system based on "wound, ischemia and foot Infection" (WIfI). This classification system, published in 2013 was created to account for the demographic changes that have occurred over the past forty years including increased incidence of high blood sugar and evolving techniques and ability for revascularization.
As of 2017, two randomized clinical trials are being conducted to better understand the optimal revascularization technique for severe PAD and critical limb ischemia (CLI), the BEST-CLI (Best Endovascular Versus Best Surgical Therapy for Patients With Critical Limb Ischemia) Trial, and the BASIL-2 (Bypass Versus Angioplasty in Severe Ischaemia of the Leg – 2 )Trial.In 2011, pCMV-vegf165 was registered in Russia as the first-in-class gene therapy drug for treatment of PAD, including the advanced stage of critical limb ischemia. References
External links
"Peripheral Arterial Disease" at the National Heart, Lung and Blood Institute
Peripheral Arterial Disease (P.A.D.) at the American College of Foot and Ankle Surgeons
Gerhard-Herman, Marie D.; Gornik, Heather L.; Barrett, Coletta; Barshes, Neal R.; Corriere, Matthew A.;  et al. (November 13, 2016). "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease: Executive Summary". Circulation. 135 (12): e686–e725. doi:10.1161/CIR.0000000000000470. PMC 5479414. PMID 27840332.