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Chapter 9
Duplex assessment of lower limb arterial disease
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INTRODUCTION
Duplex scanning of the lower limb arteries is a well-established technique and provides comparable results to arteriography (Legemate et al 1989, Pemberton & London 1997). In most cases, this allows the vascular surgeon or physician to formulate a management plan without the aid of diagnostic arteriograms, which are known to carry a complica- tion rate of 1–2% (Egglin et al 1995). For instance, it may be decided to treat the patient by conservative methods without further investigations. Vascular radiologists can spend less time performing diagnos- tic arteriograms, concentrating their skills on thera- peutic treatment by balloon angioplasty. In some centers the patient undergoes surgery on the basis of diagnostic duplex scanning alone (McCarthy et al 1999, Proia et al 2001). This chapter provides an overview of lower limb arterial disorders and offers practical advice on color duplex scanning of periph- eral arteries.
ANATOMY OF THE LOWER LIMB ARTERIAL SYSTEM
The anatomy of the lower limb arterial system is demonstrated in Figure 9.1. The abdominal aorta has been included in this section, as it can be a source of lower limb symptoms.
The aorta lies slightly to the left of the midline in the abdomen, and its bifurcation is located at the level of the fourth lumbar vertebra in the region of the umbilicus. The aorta divides into the left and right common iliac arteries (CIA) at the
CHAPTER CONTENTS
Introduction 111
Anatomy of the lower limb arterial system 111
Collateral pathways and anatomical variations 113
Ankle–brachial pressure measurements and exercise testing 113
Symptoms of lower limb arterial disease 116
Intermittent claudication 116
Chronic critical lower limb ischemia 116 Acute ischemia 117
Practical considerations for lower extremity duplex scanning 118
Scanner setup 119
Starting the scan 119
AssessmentoftheaortoiliacarteryandCFA 119 Assessment of the femoral and popliteal
arteries 120
Assessment of the tibial arteries 122 Assessment of tibial arteries and the plantar
arch prior to bypass surgery 123 Commonly encountered problems 123
Scan appearances 124
B-mode images 124 Color flow images 125 Spectral Doppler 126
Assessment of arterial stents 129
Other abnormalities and syndromes 129
Popliteal entrapment syndrome 129 Cystic adventitial disease of the popliteal
artery 130
Reporting 130