Insights On Testing And Treatment Of Ischemic Wounds
Ischemic wounds can be challenging for any physician. With this in mind, the panelists discuss key indicators to look for in the history and physical exam, the effectiveness of noninvasive vascular testing and parameters for performing an amputation after bypass surgery. They also explore the treatment possibilities of angioplasty/stenting and the long leg distal bypass. Without further delay, here is what they had to say. Q: What is your workup/treatment plan when a new patient presents with an ischemic foot wound? A: Mark Beylin, DPM, says it starts by determining the patient’s chief complaints. He asks the patient for a full and clear chronological account of his or her symptoms, including initial onset, duration, attempted treatment (if any) and if there’s any history of previous episodes, etc. Richard Stillman, MD, determines if the patient has any symptoms, such as intermittent claudication or leg pain at rest, that are suggestive of arterial insufficiency. Not only is the medical history important, but Dr. Beylin notes the patient’s social history, in regard to smoking, alcohol and drug use, can reveal a direct relationship to developing an ischemic disease. He also says the patient’s family history may reveal the risk of developing certain diseases. When performing the physical examination, Dr. Stillman checks the extremity for the absence of femoral, popliteal, dorsalis pedis or posterior tibial pulses. However, he cautions that approximately 10 percent of the normal population lacks a dorsalis pedis pulse. Dr. Stillman also encourages physicians to listen for bruits, especially overlying the iliofemoral segment. When palpating the pulses, Dr. Beylin says you should also note the presence or absence of aneurysmal dilation. Dr. Stillman emphasizes recording the status of venous and capillary refilling, and noting the existence of skin atrophy, the presence of cyanosis or dependent rubor and the absence of hair growth on the toes. If you suspect arterial insufficiency, Dr. Beylin recommends checking the amount of pallor on the lower extremities upon elevation. He also checks for asymmetry, edema, stasis pigmentation, inflammatory changes, and dilated veins as well as the condition of the patient’s skin and nails. Often these patients will require a more extensive workup and Dr. Beylin says he refers them to a vascular or endovascular specialist. If the wound appears to be infected, Dr. Beylin will obtain a culture, begin preliminary antibiotics and seek an infectious diseases consult. Q: What role does noninvasive vascular testing play in the management of these wounds? What absolute toe pressure numbers do you consider adequate for healing? A: Dr. Beylin calls noninvasive vascular testing a “very useful tool” in determining a general idea of a vascular compromise. Specifically, he uses testing such as arterial/venous duplex scanning, limb blood pressures, velocity patterns and transcutaneous toe pressures. In his opinion, Dr. Beylin believes transcutaneous toe pressures greater than 40 mm are adequate for healing in most patients. Lawrence Karlock, DPM, has found that an absolute toe pressure of greater than 55 mmHg with a biphasic pedal pulse is usually satisfactory for healing while a toe pressure less than 30 mmHg is not conducive for healing. Dr. Karlock says he employs noninvasive vascular testing to obtain absolute toe pressures for patients who have any signs of a non-healing, ischemic ulcer. He prefers to use an accredited vascular lab. He says doing so gives him an objective measure of the patient’s healing potential even in the face of calcified lower extremity vessels. Other tests can be misleading according to Dr. Stillman. He says this is particularly the case when trying to use ankle-brachial pressure indices to assess patients with diabetes. Dr. Stillman points out these patients may have poorly compressible calcified arteries that tend to give normal or high pressures despite poor flow. While ultrasonic visualization of arterial anatomy does help identify aneurysmal disease or ulcerated plaque, Dr. Stillman says it generally correlates poorly with hemodynamic data. When one employs noninvasive arterial blood flow testing (such as pulse volume recording and plethysmography), pneumatic cuffs encircle the thighs, calves, ankles, feet and, sometimes, individual toes, according to Dr. Stillman.