Chronic limb threatening ischemia (CLTI), also known as critical limb ischemia (CLI), is an advanced stage of
peripheral artery disease (PAD). It is defined as ischemic rest pain,
arterial insufficiency ulcer
Arterial insufficiency ulcers (also known as ischemic ulcers, or ischemic wounds) are mostly located on the lateral surface of the ankle or the distal digits. They are commonly caused by peripheral artery disease (PAD).
Characteristics
The ulcer ...
s, and
gangrene. The latter two conditions are jointly referred to as tissue loss, reflecting the development of surface damage to the limb
tissue due to the most severe stage of
ischemia. Compared to the other manifestation of PAD,
intermittent claudication, CLI has a negative prognosis within a year after the initial diagnosis, with 1-year amputation rates of approximately 12% and mortality of 50% at 5 years and 70% at 10 years.
CLI was conceived to identify patients at high-risk for
major amputation, but the increasing prevalence of
diabetes mellitus
Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...
has led to a broader conception of limb threat that includes the risk of amputation associated with severely
infected and non-healing
wounds.
Signs and symptoms
Critical limb ischemia includes rest pain and tissue loss.
Rest pain
Rest pain is a continuous burning
pain of the
lower leg
The human leg, in the general word sense, is the entire lower limb of the human body, including the foot, thigh or sometimes even the hip or gluteal region. However, the definition in human anatomy refers only to the section of the lower limb e ...
or
feet
The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
. It begins, or is aggravated, after reclining or elevating the limb and is relieved by sitting or standing. It is more severe than
intermittent claudication, which is also a pain in the legs from
arterial insufficiency.
Tissue loss
Tissue loss is the development of
arterial insufficiency ulcers or
gangrene due to
peripheral artery disease
Peripheral artery disease (PAD) is an abnormal narrowing of arteries other than those that supply the heart or brain. When narrowing occurs in the heart, it is called coronary artery disease, and in the brain, it is called cerebrovascular dis ...
.
Diagnosis
Critical limb ischemia is diagnosed by the presence of ischemic rest pain, and an ulcers that will not heal or gangrene due to insufficient blood flow.
[ Insufficient blood flow may be confirmed by ankle-brachial index (ABI), ankle pressure, toe-brachial index (TBI), toe systolic pressure, transcutaneous oxygen measurement (TcPo2 ), or skin perfusion pressure (SPP).]Buerger's test
Buerger's test is used in an assessment of arterial sufficiency. It is named after Leo Buerger. The ''vascular angle'', which is also called ''Buerger's angle'', is the angle to which the leg has to be raised before it becomes pale, whilst lying d ...
, a capillary refill of more than 15 seconds or diminished or absent pulses.
Critical limb ischemia is different from acute limb ischemia. Acute limb ischemia is a sudden lack of blood flow to the limb, for example caused by an embolus whereas critical limb ischemia is a late sign of a progressive chronic disease.
Treatment
Treatment mirrors that of other symptoms of peripheral artery disease
Peripheral artery disease (PAD) is an abnormal narrowing of arteries other than those that supply the heart or brain. When narrowing occurs in the heart, it is called coronary artery disease, and in the brain, it is called cerebrovascular dis ...
, and includes modifying risk factors
In epidemiology, a risk factor or determinant is a variable associated with an increased risk of disease or infection.
Due to a lack of harmonization across disciplines, determinant, in its more widely accepted scientific meaning, is often use ...
, revascularization
In medical and surgical therapy, revascularization is the restoration of perfusion to a body part or organ that has had ischemia. It is typically accomplished by surgical means. Vascular bypass and angioplasty are the two primary means of rev ...
via vascular bypass
A vascular bypass is a surgical procedure performed to redirect blood flow from one area to another by reconnecting blood vessels. Often, this is done to bypass around a diseased artery, from an area of normal blood flow to another relatively nor ...
or angioplasty
Angioplasty, is also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atheroscle ...
, and in the case of tissue loss, wound debridement
Debridement is the medical removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue. Removal may be surgical, mechanical, chemical, autolytic (self-digestion), and by maggot therapy.
In p ...
.
Research
As of 2015 pCMV-vegf165, a gene-therapy was being studied in critical limb ischemia.
References
External links
Cochrane Peripheral Vascular Diseases Review Group
{{Vascular diseases
Hypertension