ASK DIS: Critical limb ischemia (CLI)

Critical limb ischemia (CLI) is a severe blockage in the arteries of the lower extremities, which markedly reduces blood-flow.
It is a serious form of peripheral arterial disease, or PAD, but less common than claudication.
PAD is caused by atherosclerosis, the hardening and narrowing of the arteries over time due to the buildup of fatty deposits called plaque.
CLI is a chronic condition that results in severe pain in the feet or toes, even while resting.
Complications of poor circulation can include sores and wounds that won't heal in the legs and feet.
Left untreated, the complications of CLI will result in amputation of the affected limb.

Treatment

1. Endovascular treatments
Minimally invasive endovascular therapy is often an option in the care of CLI:

Angioplasty: A tiny balloon is inserted through a puncture in the groin. The balloon is inflated one or more times, using a saline solution, to open the artery.

Cutting balloon: A balloon imbedded with micro-blades is used to dilate the diseased area. The blades cut the surface of the plaque, reducing the force necessary to dilate the vessel.
Cold balloon (CryoPlasty): Instead of using saline, the balloon is inflated using nitrous oxide. The gas freezes the plaque. The procedure is easier on the artery; the growth of the plaque is halted; and little scar tissue is generated.

Stents: Metal mesh tubes that provide scaffolding are left in place after an artery has been opened using a balloon angioplasty.

Balloon-expanded: A balloon is use to expand the stent. These stents are stronger but less flexible.
Self-expanding: Compressed stents are delivered to the diseased site. They expand upon release. These stents are more flexible.

Laser atherectomy: Small bits of plaque are vaporized by the tip of a laser probe.
Directional atherectomy: A catheter with a rotating cutting blade is use to physically remove plaque from the artery, opening the flow channel.

2. Surgical treatments

Treatment of wounds or ulcers may require additional surgical procedures or other follow-up care.
If the arterial blockages are not favorable for endovascular therapy, surgical treatment is often recommended.
Typically involves bypass around the diseased segment with either a vein from the patient or a synthetic graft.
Hospitalization after a bypass operation varies from a few days to more than a week.
Recovery from surgery may take several weeks

3. Amputation:

The last recourse would be amputation of a toe, part of the foot, or leg. Amputation occurs in about 25% of all CLI patients

4. Medications Therapy

Thrombolytic

Catheter-based intraarterial thrombolytic therapy is an alternative to surgery or percutaneous intervention in the management of acute thrombosis superimposed on chronic stenosis or occlusion in patients with critical limb ischemia
2005 ACC/AHA guidelines on Peripheral Artery Disease (PAD), concluded that there was general agreement that catheter-based thrombolytic therapy is effective and beneficial and is indicated in patients with acute limb ischemia of fewer than 14 days duration
Thrombolytic drugs in clinical use for leg arterial occlusion are streptokinase, urokinase, and recombinant human tissue-type plasminogen activator (rt- PA, alteplase).
There are no data to support the routine use of primary pharmacologic therapy in patients with critical leg ischemia, and the best therapeutic options are revascularization with surgery or PTA.
However, many patients are poor candidates for either procedure because of concomitant diseases or unfavorable anatomy

Antithrombotic Therapy

Intravenous heparin at full anticoagulant dosage should be administered as soon as possible (unless there is a specific contraindication to such therapy) and continued until other interventions, such as thrombolysis, are initiated.
This is intended to reduce recurrent emboli and to prevent propagation of thrombus

Risk Reduction

Following lower extremity arterial bypass, the benefits of the long-term administration of antithrombotic therapy remain unclear.
ACCP guideline on antithrombotic therapy for peripheral artery occlusive disease made the following recommendations for the use of antithrombotic agents in patients undergoing infrainguinal vascular surgery
Aspirin

(75 to 100 mg/day) should begin preoperatively and continue indefinitely in all patients undergoing infrainguinal bypass or arterial reconstruction.

are not routinely recommended in patients undergoing infrainguinal arterial reconstruction or bypass, except in those at high risk of bypass occlusion and limb loss.

major society guidelines recommend long-term aspirin therapy or clopidogrel for all patients with atherosclerotic peripheral artery disease

Prevention

Several medications may be prescribed to prevent further progression of the disease and to reduce the effect of contributing factors such as high blood pressure, high cholesterol and diabetes, and most certainly to reduce the pain.

References

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