From the Guidelines
Peripheral Arterial Disease (PAD), Critical Limb Ischemia (CLI), and Acute Limb Ischemia (ALI) are distinct clinical subsets of patients with lower extremity peripheral artery disease, with PAD being the broader condition, CLI representing an advanced stage with chronic severe ischemia, and ALI being a sudden and severe decrease in limb perfusion requiring immediate intervention 1.
Key Differences
- PAD is characterized by narrowing of peripheral arteries, typically due to atherosclerosis, causing reduced blood flow to the limbs, with symptoms including intermittent claudication, but many patients remain asymptomatic 1.
- CLI is an advanced stage of PAD where blood flow is severely reduced, resulting in rest pain, non-healing ulcers, or gangrene, and represents a chronic condition that develops over time and threatens limb viability if not treated 1.
- ALI, in contrast, is a sudden decrease in limb perfusion, typically due to an embolism or thrombosis, causing the "six Ps": pain, pallor, pulselessness, paresthesia, paralysis, and poikilothermia (cold limb), and is a medical emergency requiring immediate intervention to prevent tissue death and limb loss, typically within hours 1.
Clinical Presentation
- PAD: intermittent claudication, asymptomatic, or atypical leg symptoms 1.
- CLI: rest pain, non-healing ulcers, or gangrene 1.
- ALI: sudden onset of pain, pallor, pulselessness, paresthesia, paralysis, and poikilothermia (cold limb) 1.
Management
- PAD: lifestyle modifications, medical therapy, and revascularization procedures 1.
- CLI: revascularization procedures, wound care, and management of comorbidities 1.
- ALI: immediate revascularization, anticoagulation, and management of comorbidities 1.
Prognosis
- PAD: increased risk of major adverse cardiovascular events (MACE), including mortality 1.
- CLI: high risk of amputation and mortality if left untreated 1.
- ALI: high risk of limb loss and mortality if not promptly treated 1.
From the Research
Definition and Differences
- PAOD (Peripheral Arterial Occlusive Disease) refers to a condition where the arteries that supply blood to the limbs are narrowed or blocked, leading to reduced blood flow [(2,3,4)].
- CLI (Critical Limb Ischemia) is a severe form of PAOD, characterized by chronic ischemic rest pain, ulcers, or gangrene in one or both legs [(2,5,6)].
- ALI (Acute Limb Ischemia) is not explicitly defined in the provided studies, but it can be inferred as a condition where there is a sudden loss of blood flow to a limb, as opposed to the chronic nature of CLI 6.
Key Characteristics
- PAOD is a broader term that encompasses various stages of peripheral artery disease, including intermittent claudication and CLI [(3,4)].
- CLI is a more advanced stage of PAOD, with a higher risk of amputation, myocardial infarction, stroke, and vascular death [(2,5,6)].
- The goals of treatment for PAOD and CLI differ, with PAOD focusing on preventing cardiovascular events and improving symptoms, while CLI aims to promote wound healing, limb salvage, and prevent amputation [(3,5,4)].
Treatment Options
- Treatment for PAOD includes lifestyle modifications, risk factor management, antiplatelet therapy, and endovascular interventions [(3,4)].
- Treatment for CLI involves a multidisciplinary approach, including medical therapy, surgical interventions, and endovascular techniques [(2,5)].
- The use of antithrombotic agents, such as antiplatelet therapy and anticoagulation, is crucial in the management of PAOD and CLI [(3,4)].