From the Guidelines
Chronic limb ischemia (CLI) is the most advanced stage of peripheral arterial occlusive disease (PAOD), characterized by persistent rest pain, tissue loss, ulceration, or gangrene due to severely reduced blood flow to the limbs, whereas PAOD is a broader term that refers to any obstruction of arteries outside the heart and brain, most commonly affecting the legs. The key difference between CLI and PAOD lies in their severity and progression, with CLI representing a critical situation where the blood supply is insufficient even at rest, putting the limb at risk for amputation if not treated promptly 1. While PAOD patients may experience pain only during activity, CLI patients have constant pain, even at rest, particularly at night, and require urgent intervention, typically through revascularization procedures like bypass surgery or endovascular techniques 1. Some key characteristics of CLI include:
- Persistent rest pain
- Tissue loss
- Ulceration
- Gangrene
- Severely reduced blood flow to the limbs In contrast, PAOD may be asymptomatic or may present with intermittent claudication, which is pain in the legs that occurs during walking and resolves with rest 1. The progression from PAOD to CLI occurs when arterial narrowing becomes so severe that baseline metabolic needs cannot be met, resulting in tissue death and potential limb loss 1. Revascularization is the central component of CLI management, aiming to improve blood flow to the limb, prevent amputation, and minimize tissue loss 1. Factors influencing revascularization strategy for CLI include lesion characteristics, availability of high-quality autogenous vein conduit, and technical aspects of surgery, as informed by trials such as the BEST-CLI and BASIL-2 trials 1. Overall, the distinction between CLI and PAOD is crucial, as it guides the management approach, with CLI requiring urgent and aggressive intervention to prevent limb loss and improve patient outcomes 1.
From the Research
Definition and Diagnosis
- Chronic limb ischemia (CLI) is defined as greater than 2 weeks of extremity rest pain, ulcers or extremity gangrene, secondary to objectively proven peripheral artery disease 2.
- Peripheral arterial occlusive disease (PAOD) is a broader term that encompasses a range of conditions, including intermittent claudication and CLI 3.
- CLI is considered the end-stage of PAOD, requiring a thoughtful and multidisciplinary approach, risk-benefit analysis and treatment of comorbid conditions 2.
Treatment Options
- Treatment options for CLI include medical therapy, revascularization, and amputation 4, 5, 2.
- Medical therapy for CLI involves wound care, antiplatelet therapy, anti-inflammatory therapy, and treatment of underlying conditions like diabetes mellitus, hyperlipidemia, and hypertension 2.
- Revascularization options include surgical bypass, endovascular therapy, and hybrid therapy 4, 5.
- Endovascular techniques include percutaneous transluminal angioplasty, bare metal stents, atherectomy, drug-coated balloon, and drug-eluting stents 2.
Differences between CLI and PAOD
- CLI is a more advanced and severe form of PAOD, characterized by rest pain, ulcers, or gangrene 2.
- PAOD, on the other hand, encompasses a range of conditions, including intermittent claudication, which is characterized by pain in the legs during exercise 3.
- Treatment goals for CLI and PAOD differ, with CLI requiring a more aggressive and multidisciplinary approach to prevent amputation and improve quality of life 2.
- Risk factor modification is important for both CLI and PAOD, involving tobacco cessation, and treatment of underlying conditions like diabetes mellitus, hyperlipidemia, and hypertension 3, 2.