Page 203 - Libro 2

12
Ultrasound Following Interventional Procedures
Dennis F. Bandyk
OBJECTIVES
KEY TERMS
duplex ultrasound | peripheral angioplasty | stent angioplasty | surveillance
GLOSSARY
angioplasty a surgical repair of a blood vessel by reconstructing or replacing part of the vessel; balloon angioplasty is a specific type of angioplasty in which a balloon-tipped catheter is used to enlarge a narrowing (stenosis) in a blood vessel
atherectomy a nonsurgical procedure to remove plaque from an artery using a special catheter with a device at the tip that cuts away the plaque
Vascular diagnostics are integral to the care of pa- tients with peripheral arterial disease (PAD) prior to and following endovascular intervention. Care of the PAD patient includes medical treatment (atheroscle- rotic risk factor reduction, antiplatelet medications, exercise training, and drug therapy for claudication) and in selected patients with symptoms or signs of ad- vanced limb ischemia, intervention by surgical recon- struction/bypass grafting or endovascular therapy.1 The type of intervention depends primarily on disease location and extent, which can be accurately deter- mined using duplex ultrasound, but comorbid medical conditions and the risk–benefit ratio of the proposed procedure also influence treatment decisions. Endo- vascular therapy has become a preferred initial inter- vention with a variety of techniques available to treat lower and upper limb atherosclerotic occlusive (ASO) disease (Table 12-1).1–6 The method of lesion repair,
dissection a tear along the inner layer of an artery, which results in the splitting or separation of the walls of a blood vessel
hyperplasia an abnormal increase in the number of cells;
myointimal hyperplasia an increase in the number of smooth muscle cells within the intima in response to vessel injury
stent a tubelike structure placed inside a blood vessel to provide patency and support
stenosis-free patency, and failure mode varies with intervention techniques. Percutaneous transluminal angioplasty (PTA) is the most common endovascular procedure and requires passage of guide wire across a stenosis or occlusion followed by inflation of angio- plasty balloon or deployment of a stent to expand the artery lumen. Other endovascular techniques such as subintimal angioplasty, mechanical atherectomy (plaque debulking or excision), or stent-graft angio- plasty can treat more extensive (longer stenotic seg- ments or occlusion, multiple lesions) atherosclerotic occlusive disease.5–10 Often, endovascular therapy does not restore normal peripheral pulses because of multilevel disease, especially in limbs treated for criti- cal limb ischemia (CLI). The outcome of endovascu- lar intervention is largely dependent on the procedure indication (claudication versus CLI) and lesion sever- ity classified using the Trans-Atlantic Inter-Society
List the types of commonly performed interventions
Describe the pathology observed on ultrasound during postinterventional evaluations
Define the ultrasound criteria applied to vessels following angioplasty and stenting
Identify normal and abnormal spectral Doppler waveforms obtained from vessels following angioplasty and stenting
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