Stem Cell Therapy for Peripheral Arterial Disease

Peripheral vascular disease (PVD), commonly referred to as peripheral arterial disease (PAD) or peripheral artery occlusive disease (PAOD), refers to the obstruction of large arteries not within the coronary, aortic arch vasculature, or brain. PVD can result from atherosclerosis, inflammatory processes leading to stenosis, an embolism, or thrombus formation. It causes either acute or chronic ischemia (lack of blood supply). Often peripheral arterial disease(PAD) is a term used to refer to atherosclerotic blockages found in the lower extremity.

PVD also includes a subset of diseases classified as microvascular diseases resulting from episodal narrowing of the arteries (Raynaud’s phenomenon), or widening thereof (erythromelalgia), i.e. vascular spasms.

Levels of disability are divided into 6 subsets. The classification system, by Rutherford, consists of three grades and six categories:
Mild claudication
Moderate claudication
Severe claudication
Ischemic pain at rest
Minor tissue loss
Major tissue loss
Symptoms
About 20% of patients with mild peripheral arterial disease(PAD) may be asymptomatic; other symptoms include:[1]
Claudication – pain, weakness, numbness, or cramping in muscles due to decreased blood flow,Sores, wounds, or ulcers that heal slowly or not at all.

Noticeable change in color (blueness or paleness) or temperature (coolness) when compared to the other limb
Diminished hair and nail growth on affected limb and digits.

Bouchard’s nodes and Heberden’s nodes may form in osteoarthritis
The main symptom is pain, causing loss of ability and often stiffness. “Pain” is generally described as a sharp ache, or a burning sensation in the associate muscles and tendons. OA can cause a crackling noise (called “crepitus”) when the affected joint is moved or touched, and patients may experience muscle spasm and contractions in the tendons. Occasionally, the joints may also be filled with fluid. Humid and cold weather increases the pain in many patients.

OA commonly affects the hands, feet, spine, and the large weight bearing joints, such as the hips and knees, although in theory, any joint in the body can be affected. As OA progresses, the affected joints appear larger, are stiff and painful, and usually feel better with gentle use but worse with excessive or prolonged use, thus distinguishing it from rheumatoid arthritis.

In smaller joints, such as at the fingers, hard bony enlargements, called Heberden’s nodes (on the distal interphalangeal joints) and/or Bouchard’s nodes (on the proximal interphalangeal joints), may form, and though they are not necessarily painful, they do limit the movement of the fingers significantly. OA at the toes leads to the formation of bunions, rendering them red or swollen. Some people notice these physical changes before they experience any pain.OA is the most common cause of joint effusion, sometimes called water on the knee in lay terms, an accumulation of excess fluid in or around the knee joint.

Risk factors contributing to peripheral arterial disease(PAD) are the same as those for therosclerosis:
Smoking – tobacco use in any form is the single most important modifiable cause of PVD internationally. Smokers have up to a tenfold increase in relative risk for PVD in a dose-related effect. Exposure to second-hand smoke from environmental exposure has also been shown to promote changes in blood vessel lining (endothelium) which is a precursor to atherosclerosis.

Diabetes mellitus – causes between two and four times increased risk of PVD by causing endothelial and smooth muscle cell dysfunction in peripheral arteries. Diabetics account for up to 70% of nontraumatic amputations performed, and a known diabetic who smokes runs an approximately 30% risk of amputation within 5 years.

Dyslipidemia (high low density lipoprotein [LDL] cholesterol, low high density lipoprotein [HDL] cholesterol) – elevation of total cholesterol, LDL cholesterol, and triglyceride levels each have been correlated with accelerated peripheral arterial disease(PAD). Correction of dyslipidemia by diet and/or medication is associated with a major improvement in short-term rates of heart attack and stroke This benefit is gained even though current evidence does not demonstrate a major reversal of peripheral and/or coronary atherosclerosis.
Hypertension – elevated blood pressure is correlated with an increase in the risk of developing peripheral arterial disease(PAD), as well as in associated coronary and cerebrovascular events (heart attack and stroke).

Risk of peripheral arterial disease(PAD) also increases in individuals who are over the age of 50, male, obese, or with a family history of vascular disease, heart attack, or stroke.Other risk factors, which are being studied, include levels of various inflammatory mediators such as C-reactive protein, homocysteine.

Upon suspicion of PVD, the first-line study is the ankle brachial pressure index (ABPI/ABI). This non-invasive and cost effect test is easily done in your physicians office. When the blood pressure readings in the ankles are lower than that in the arms, blockages in the arteries, which provide blood from the heart to the ankle, are suspected. An ABI ratio less than 0.9 is consistent with PVD; values of ABI below 0.8 indicate moderate disease and below 0.4 imply severe ischemic disease.[1]

It is possible for conditions which stiffen the vessel walls (such as calcifications that occur in the setting of chronic diabetes) to produce false negatives usually, but not always, indicated by abnormally high ABIs (> 1.3). Such results and suspicions require further investigation using ultrasound to fully evaluate.

If your ABIs are abnormal typically a lower limb doppler ultrasound examination to look at site and extent of atherosclerosis should be ordered.? Other imaging can be performed by angiography,[1] where a catheter is inserted into the common femoral artery and selectively guided to the artery in question. While injecting a radiodense contrast agent an X-ray is taken. Any flow limiting stenoses found in the x-ray can be identified and potentially treated by atherectomy, angioplasty or stenting, however these procedure are not risk free.

Modern multislice computerized tomography (CT) scanners provide direct imaging of the arterial system as an alternative to angiography. CT provides complete evaluation of the aorta and lower limb arteries without the need for an angiogram’s arterial injection of contrast agent. This method employs a significant exposure to radiation and one should always use NAC, a supplement if contrast is used.