Chronic Venous Insufficiency
PERIPHERAL VASCULAR DISEASE
A frequent reason for consultation of the vascular surgeon is poor blood supply to the lower extremities, or lower extremity ischemia. This can manifest in the patient in a form that is life-style limiting, such as pain that occurs with walking (claudication) all the way to forms in which the patient no longer has sufficient blood to maintain the viability of the leg and must undergo an amputation. The treatment of these problems requires consideration of the patient's underlying general health, the severity of their ischemic symptoms and how amendable their particular vascular lesions are to therapy.
Claudication occurs when a patient exercises and the oxygen demands created by this exercise cannot be met. This manifests in pain, usually in the musculature of the calf. These patients have a clogged artery that allows enough flow during rest, but is not able to augment the flow when needed. It can vary from mild, in which patients can walk many blocks before having pain, to severe forms where a patient is hardly able to walk. The pain abates when the exercise stops. Objectively, tests in which the blood pressure in the arms is compared to that in the legs at different levels can demonstrate reduced pressure distal to these lesions. Invasive tests where dye is injected into the arteries and x-rays taken (angiography), are only indicated if one is considering an invasive intervention. There are now several noninvasive forms of visualizing blood vessels (MR angiography and CT angiography), but their role in diagnosing claudication has not been clearly defined.
It is important to note that only 10% of patients who present with claudication have progression of their disease to a point that the viability of their leg is in question (limb threat). Thus, for most patients the initial treatment plan is conservative. Smoking cessation and monitored exercise programs to increase walking distance are the cornerstones of conservative therapy and help many patients. There are a few medicines, most notably Trental (pentoxifylline) that help some patients with their symptoms, but many vascular surgeons do not consider them particularly useful.
If a patient's symptoms are disabling or having a deleterious effect on their lifestyle, an invasive procedure might by considered. These can range from percutaneous techniques in which access to the blood vessels is attained and then balloons used to dilate them (angioplasty) to open bypass operations where the occluded segment of artery has blood routed around it. Before any of these procedures is done, angiography is performed. If a lesion is seen that appears amendable to angioplasty, this can frequently be done at the time of the initial angioplasty. If open operation is needed, this will be scheduled after the angiograms are reviewed and the surgeon has discussed the plans and options with the patient.
When a patient has blood supply problems that is left untreated will lead to amputation, they are said to be in limb threat. There are essentially two forms of limb threat, rest pain and gangrene. Rest pain typically occurs when a patient is recumbent and their blood flow down the leg cannot overcome the pressure gradient that gravity supplies them when standing. Patients will awake from sleep with severe pain that is relieved by hanging their legs over the bed to allow gravity to augment their blood pressure. This condition has a high likelihood of leading to amputation, and intervention needs to be considered. Patients with rest pain usually undergo angiography and an invasive intervention. These patients frequently have other medical problems (heart disease, diabetes) and frequently require coordination among their various physicians.
Gangrene occurs when a segment of the lower extremity is no longer receiving any blood supply. This can occur in a limited area (such as the toes) or can affect an entire foot or even more. If it occurs slowly over time and is not purulent, this is referred to as dry gangrene. This process is not infected and can generally be allowed to define itself and be treated in a non-urgent fashion. However, in the presence of infected, or wet gangrene, urgent operation must be performed to remove the dead, infected tissue to prevent them from making the patient systemically ill. For either form, augmentation of the blood supply to the diseased lower extremity is frequently required either to limit the extent of operation to only the effected tissues or to ensure that the amputation site has enough blood supply to heal. Sometimes in the face of wet gangrene, urgent amputation is initially performed, with staged augmenting of the blood supply and closure of the amputation site. Again, these patients tend to have other medical problems, and close consultation with their other physicians is required.