ISCHEMIA

Present as:
Pain with walking, cramping in leg muscles, nonhealing wound, discoloration of leg or toes

Leg Ischemia occurs when the leg does not receive the necessary amount of oxygen (via blood circulation) that is required for the activity underway.  Ischemia of the lower extremities will manifest itself in many different ways ranging from asymptomatic (simply the presence of a blockage) to gangrene of a part of the leg.  Quite often, a patient will unknowingly have an asymptomatic blockage that is manifested by the absence of one of the pulses in the leg or by an abnormal angiogram that is usually done at the time of a cardiac catheterization.  A person will have no symptoms referable to this blockage and will only know of the abnormality when their physician informs them of it.  This is generally referred to as Fontaine’s Class I.

The next “level” of ischemia is that of claudication.  This is manifested by cramping pain that occurs with walking and is relieved with cessation of exercise.  It most often affects the calf muscles and generally occurs at a rather fixed distance (usually measured in blocks.)  Depending on the severity of the symptoms—either by its level of lifestyle interference or by distance at which symptoms begin—it is referred to as Fontaine’s Class II(a) or II(b).  

The next stage is rest pain (Fontaine Level III) in the classification of leg ischemia.  This is typified by pain that occurs at rest—that is, when a person is lying in bed or sitting down.  It often occurs in the evenings and awakens the patient from sleep.  Quite often, hanging the leg from the side of the bed will improve the painful symptoms that are experienced.  The foot will often turn a light purple or deep red-violet color as it is held in a dependent position—often referred to as “dependent rubor.”  This is a sign of significant leg ischemia and warrants aggressive intervention.  

The final stage of leg ischemia (Fontaine Level IV) is tissue loss (a non-healing sore or gangrene.)  This level (along with rest pain) is appropriately referred to as “limb-threatening ischemia” and must be evaluated appropriately by those with expertise in this area.  Ignoring this degree of ischemia will very likely lead to limb loss (amputation) at some point in the near future!


Diagnosis:
The important step in making the diagnosis is, quite simply, the recognition of this disorder.  Most cases of ischemia (Fontaine levels I and II) are often treated with lifestyle modification and risk factor adjustment alone.  However, once the symptoms have progressed to Level III (rest pain and beyond), aggressive and appropriate therapy is mandatory. 
Diagnosing limb ischemia is usually done using noninvasive means in the Noninvasive Vascular Laboratory.  Simple tests can be performed to assess the degree of arterial insufficiency.  These are tests that are noninvasive and cause no discomfort to the patient.  The Vascular Surgeon can interpret them immediately and, combined with physical examination and careful consideration of the medical history, will make appropriate recommendations regarding the care that is right for that patient.  If indicated, an angiogram may be performed to assess if a balloon angioplasty (and/or a stent) is appropriate or to plan a surgical procedure such as a bypass.  Irrespective of the procedure chosen, the goal is to improve blood flow to the limb and rid the patient of the ischemic symptoms. 

Treatment Options:
Intervention (endovascular or open surgery) should be reserved as a “last resort” for the treatment of leg ischemia.  The vast majority of patients are best served by a conservative approach to limb ischemia.  Lifestyle adjustments (such as exercise programs and nutritional counseling) and risk factor modification (cessation of tobacco use, treatment of hypercholesterolemia) have proved quite successful to patients over the years.  Physicians might recommend intervention for those with claudication that is disabling. 

Having stated a conservative approach to claudication, it is imperative to understand that an aggressive approach to limb salvage is appropriate!  Three decades ago it was believed that bypass surgery could not be performed with good results if the bypass had to extend below the level of the knee.  That belief has clearly (and appropriately) been discarded as microvascular techniques have been demonstrated, improved and perfected since the 1970s.  Bypass surgery to the vessels in the foot and ankle are routine procedures for those with proper training in the field of Vascular Surgery.  Simply suggesting an amputation of the leg without evaluating the patient for a bypass is no longer conscionable, except in the excessively old and infirmed patient who is non-ambulatory to start.  Quite often, once patients undergo a major amputation of the leg, the complications that ensue from their bedridden state lead to their demise.  We are quite proud of our results with limb salvage surgery and believe that it is an appropriate option for the great majority of patients.  We have cared for scores of patients over the years who have been informed that they had to have their leg amputated only to find that we were able to save it!

Most of our patients usually ask what intervention is best– medication, dilation (balloon angioplasty) or operation (bypass surgery)?  The answer to this question requires individualization.  Often one specific therapy is more appropriate than another; sometimes a combination of the two work best for patients.  The most important advice that a patient can receive is to make sure that the person treating them is able to do everything—that way, there is no inherent bias as to which procedure is best in that instance.