Acute arterial insufficiency is a medical condition in which the tissues do not receive enough oxygen and nutrients (ischemia) due to poor arterial blood supply.
Most cases of acute arterial insufficiency are caused by atherosclerosis, a condition in which the arteries become clogged by cholesterol plaques. This results in poor blood flow to the affected blood vessels and may also lead to the increased formation of blood clots (thrombus) due to the turbulence caused by these plaques.
The formation of blood clots can lead to two things. First, it can cause complete obstruction of the blood flow in that artery. Second, a part of the blood clot can break off (embolus or emboli) and block some other, smaller artery and cause obstruction. An acute myocardial infarction (heart attack) is one example of acute arterial insufficiency due to an embolus. Acute arterial insufficiency can also affect the small arteries of the limbs, a condition known as peripheral arterial occlusive disease (PAOD).
Acute arterial insufficiency is characterized by intermittent claudication, which is defined as muscle pain due to ischemia upon prolonged use of the involved body part. Most patients with acute arterial insufficiency of the lower extremities experience this after walking.
Patients with diabetes are at risk for acute arterial insufficiency. Diabetics suffer from a wide range of metabolic problems, among which is fats and fatty acid metabolism, increasing their risk for atherosclerosis. They are also prone to develop disease of the small vessels and nerves (diabetic neuropathy), which makes them vulnerable to ischemia. People with hypertension are also at risk because the high blood pressure within their blood vessels causes more turbulent blood flow. This can lead to thrombus formation. Smoking, a sedentary lifestyle and a high-fat diet are also risk factors that may contribute to the development of acute arterial insufficiency.
Acute arterial insufficiency is usually diagnosed by measuring the amount of blood flow and pressure to the affected arteries. Blood pressure in different segments of the affected blood vessel is measured (segmental pressure measurement). The ankle-brachial index (ABI) is another method used to diagnose peripheral arterial occlusive disease, which affects mostly the lower limbs. In this test, the pressure in the ankle is compared to the pressure in the arm. A result of 0.9 to 1.1 indicates a normal artery, while a score lower than 0.9 signifies the presence of peripheral arterial occlusive disease. The lower the ABI, the worse the PAOD. Assessment of the blood flow can also be made using a Doppler device, which is able to translate the blood flow present in a blood vessel into an audible sound. The absence of a sound when a Doppler device is placed on an artery indicates that there is no blood flowing in that area.
The treatment for acute arterial insufficiency is primarily medical and includes the use of drugs to decrease the risk of thrombus formation. These drugs may include aspirin, cilostazol, heparins (anticoagulants) or platelet inhibitors. Non-medical treatments in the form of moderate exercise, such as walking, is also important to help reduce the progression of the disease. Surgical treatment is reserved for severe cases of occlusion.