Definition of critical limb ischemia includes:-

Critical limb Ischemia CLI results from severe aerial occlusive disease in whom resting blood flow cannot provide for basal nutritional needs of tissues Ischemic symptoms are present even during rest (rest pain) Pain is worse when legs are horizontal and may improve when legs are kept in a dependent position. Ischemic ulcers, lesions on the foot and gangrene may be seen ABI < 0.5