Dr. Billy Kim, a Vascular Surgeon with The Surgical Clinic, treats patients with Peripheral Arterial Disease (PAD). People with PAD normally experience some sort of pain in their legs. Sometimes this pain occurs while at rest and sometimes it is experienced during times of activity. Understanding your risk factors for PAD can help patients change some aspects of the disease process.
There are several risk factors which have been shown to be associated with PAD. These risk factors can further be delineated by those which cannot be modified, such as age, and those which can be, such as cigarette smoking, diabetes and hypertension. Several large population studies demonstrate that the incidence of Intermittent Claudication (IC) and Critical Limb Ischemia (CLI) increase with age. No real surprise there.
Smoking has been shown to be an independent risk factor for the development of PAD. There is a two-to-six-fold increase in the risk of developing PAD. In fact, the association of smoking with PAD is thought to be stronger than its association with coronary artery disease. The severity of PAD appears also to be directly proportional to the number of cigarettes smoked in ones lifetime. The good news is that smoking cessation has been associated with a decline in the incidence of IC.
Diabetes mellitus is associate with a twofold increase in the risk of developing PAD. The risk is directly proportional to the severity and duration of diabetes. For every 1% increase in hemoglobin A1C, a corresponding 26% increase has been suggested in the risk of developing PAD. The other issues with diabetes is poor wound healing in addition to peripheral neuropathy. Therefore it does carry a five to tenfold increase in the rate of major amputations compared to nondiabetics. With this understanding, it is paramount to have a good control of the hemoglobin A1C, through evaluation of the feet on a daily basis, especially those with peripheral neuropathy.
Elevated total serum cholesterol, low-density lipoprotein (LDL) cholesterol, decreased high-density lipoprotein(HDL), and hypertriglyceridemia have been associated with an increased risk of developing PAD. This risk is increased by 5% to 10% for every 10 mg/dl rise in total cholesterol. The best predictor for PAD was the ratio of total to HDL cholesterol. In addition, smoking seems to enhance the effects of hypercholesterolemia. Low serum HDL levels may also be related to smoking and reduced physical activity. Therefore evidence suggests that control of serum cholesterol and triglyceride levels decrease both the incidence and the progression of PAD. Recommendations include aggressive treatment of these patients with lipid lowering drugs (statins), which is also true for patients with coronary artery disease.
Hypertension is associated with an increased risk of developing PAD. However this association is weaker than for cerebrovascular and coronary disease. In addition, hypertension risk factor is less when compared to smoking and diabetes.
Something that is not talked about a great deal is hyperhomocysteinemia. Increased levels of homocysteine levels are detected in approximately 30-40% of patients with lower extremity PAD. This association between hyperhomocysteinemia and PAD has been suggested to be stronger than for coronary artery disease.
Patients with PAD are not only at risk for progression of disease but also for other significant cardiovascular events such as myocardial infarction (20-60% increased) and stroke (40%). Interestingly enough though, the clinical course for PAD in regards to the legs are fairly stable. Only a quarter of patients with intermittent claudication will ever deteriorate significantly. This is attributed to the develop of collaterals, metabolic adaption of ischemic muscle, and the alternation of gait to favor nonischemic muscle groups. Therefore a worsening ankle-brachial index (ABI) is the best predictor for deterioration of PAD. However for patients with CLI, 60-90% require some form of revascularization procedure. These patients generally have a poor prognosis. At 1 year, only 25% of these patients have resolution of their symptoms, 20% continue to have symptoms, 30% have undergone an amputation, and 25% are dead. In those patients who have unreconstructable disease or attempts at reconstruction have failed, the 6 month follow up results indicated that approximately 40% end up with an amputation and 20% die.
Traditional treatment goals for intermittent claudication are to relieve symptoms of pain while walking, to increase walking capacity, and to improve quality of life. The approach for these patient involved a multi-faceted approach to address the risk factors, pharmacologic agents (antiplatelet agents, phosphodiesterase inhibitor, statins) and invasive procedures. These invasive procedures include endovascular interventions such as angioplasty, stent, atherectomy and combination. More invasive procedures would include endarterectomy, thrombectomy and bypasses.
At The Surgical Clinic, PLLC, board-certified vascular surgeons are trained and equipped to assess, identify and provide various treatment options for our patients. This may include conservative risk and behavior modifications, pharmacologic agents. Depending on the severity of IC and CLI, the next steps may include invasive interventions which we will provide the full spectrum of treatment tailored to the needs of the patients.