Page 161 - Libro 2

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Duplex Ultrasound of Lower Extremity Arteries
Natalie Marks, Anil Hingorani, and Enrico Ascher
OBJECTIVES
KEY TERMS
aneurysm | contrast arteriography | duplex arteriography| peak systolic velocity| plaque
GLOSSARY
aneurysm a localized dilation of an artery involv- ing all three layers of the arterial wall
contrast arteriography a radiologic imaging technique performed using ionizing radiation to provide detailed arterial system configuration and pathology information
Contrast arteriography (CA) has been used for de- cades as the gold standard imaging tool to evaluate the peripheral arterial system particularly prior to lower extremity revascularization procedures. It is well-known that CA is associated with systemic and local complications and, nowadays, media-educated patients are demanding less invasive alternatives. Current technical advances in ultrasonographic im- aging have motivated a number of authors to inves- tigate the potential of duplex arteriography (DA) to replace standard CA in the assessment of the arterial system.1–13 Although many authors have demonstrat- ed a promising association between arteriography and DA,1–9 others have been less enthusiastic and continue to promote preoperative or prebypass arte- riography.10–13 There are several factors contributing to this results discrepancy, such as: (1) lack of so- nographers and vascular technologists’ experience, (2) lack of commitment of time and effort to perfect the technique, (3) outdated duplex equipment with poor imaging quality, (4) surgeon’s unwillingness to give up the visual effect of a complete arteriogra- phy and incorporate a perception of duplex imaging,
duplex arteriography ultrasound imaging of the arterial system performed to identify atheroscle- rotic disease and other arterial pathology proving a detailed map of the arterial system evaluated
plaque the deposit of fatty material within the ves- sel walls, which is characteristic of atherosclerosis
and (5) heavy vessel calcification and other local obstacles preventing adequate insonation in some patients.
It has been the experience of these authors to preferentially use DA since 1998. At first, the utility of DA was explored for purely diagnostic purposes in patients undergoing lower extremity revascular- izations.14–17 Over the last 6 years, DA was applied not only to diagnostic use but also for endovascular procedures such as duplex-guided angioplasties.18–21 The use of intraoperative and postendovascular arte- rial ultrasound will be discussed in subsequent chap- ters of this text. This chapter will explore DA in the diagnosis of disease in the lower extremity arterial system.
INDICATIONS
Signs and symptoms of arterial disease, which were described in the preceding chapter on indi- rect arterial testing, also apply to a patient present- ing for a lower extremity arterial duplex ultrasound
Describe the ultrasound techniques used to image lower extremity arteries
Define normal image and Doppler characteristics of peripheral arteries
Identify peripheral arterial abnormal waveforms
Describe the use of ultrasound with arterial revascularization procedures
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